linux/net/ipv4/ping.c

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// SPDX-License-Identifier: GPL-2.0-or-later
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* "Ping" sockets
*
* Based on ipv4/udp.c code.
*
* Authors: Vasiliy Kulikov / Openwall (for Linux 2.6),
* Pavel Kankovsky (for Linux 2.4.32)
*
* Pavel gave all rights to bugs to Vasiliy,
* none of the bugs are Pavel's now.
*/
#include <linux/uaccess.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <net/snmp.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/protocol.h>
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/export.h>
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
#include <net/sock.h>
#include <net/ping.h>
#include <net/udp.h>
#include <net/route.h>
#include <net/inet_common.h>
#include <net/checksum.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <linux/in6.h>
#include <linux/icmpv6.h>
#include <net/addrconf.h>
#include <net/ipv6.h>
#include <net/transp_v6.h>
#endif
struct ping_table {
struct hlist_nulls_head hash[PING_HTABLE_SIZE];
rwlock_t lock;
};
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
static struct ping_table ping_table;
struct pingv6_ops pingv6_ops;
EXPORT_SYMBOL_GPL(pingv6_ops);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
static u16 ping_port_rover;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
u32 res = (num + net_hash_mix(net)) & mask;
pr_debug("hash(%u) = %u\n", num, res);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
return res;
}
EXPORT_SYMBOL_GPL(ping_hash);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
struct net *net, unsigned int num)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
}
int ping_get_port(struct sock *sk, unsigned short ident)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
struct hlist_nulls_node *node;
struct hlist_nulls_head *hlist;
struct inet_sock *isk, *isk2;
struct sock *sk2 = NULL;
isk = inet_sk(sk);
write_lock_bh(&ping_table.lock);
if (ident == 0) {
u32 i;
u16 result = ping_port_rover + 1;
for (i = 0; i < (1L << 16); i++, result++) {
if (!result)
result++; /* avoid zero */
hlist = ping_hashslot(&ping_table, sock_net(sk),
result);
ping_portaddr_for_each_entry(sk2, node, hlist) {
isk2 = inet_sk(sk2);
if (isk2->inet_num == result)
goto next_port;
}
/* found */
ping_port_rover = ident = result;
break;
next_port:
;
}
if (i >= (1L << 16))
goto fail;
} else {
hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
ping_portaddr_for_each_entry(sk2, node, hlist) {
isk2 = inet_sk(sk2);
/* BUG? Why is this reuse and not reuseaddr? ping.c
* doesn't turn off SO_REUSEADDR, and it doesn't expect
* that other ping processes can steal its packets.
*/
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if ((isk2->inet_num == ident) &&
(sk2 != sk) &&
(!sk2->sk_reuse || !sk->sk_reuse))
goto fail;
}
}
pr_debug("found port/ident = %d\n", ident);
isk->inet_num = ident;
if (sk_unhashed(sk)) {
pr_debug("was not hashed\n");
sock_hold(sk);
hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
}
write_unlock_bh(&ping_table.lock);
return 0;
fail:
write_unlock_bh(&ping_table.lock);
return 1;
}
EXPORT_SYMBOL_GPL(ping_get_port);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
int ping_hash(struct sock *sk)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
BUG(); /* "Please do not press this button again." */
return 0;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
void ping_unhash(struct sock *sk)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
struct inet_sock *isk = inet_sk(sk);
pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
write_lock_bh(&ping_table.lock);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (sk_hashed(sk)) {
hlist_nulls_del(&sk->sk_nulls_node);
sk_nulls_node_init(&sk->sk_nulls_node);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
sock_put(sk);
isk->inet_num = 0;
isk->inet_sport = 0;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
}
write_unlock_bh(&ping_table.lock);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
EXPORT_SYMBOL_GPL(ping_unhash);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
struct sock *sk = NULL;
struct inet_sock *isk;
struct hlist_nulls_node *hnode;
int dif = skb->dev->ifindex;
if (skb->protocol == htons(ETH_P_IP)) {
pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
(int)ident, &ip_hdr(skb)->daddr, dif);
#if IS_ENABLED(CONFIG_IPV6)
} else if (skb->protocol == htons(ETH_P_IPV6)) {
pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
(int)ident, &ipv6_hdr(skb)->daddr, dif);
#endif
}
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
read_lock_bh(&ping_table.lock);
ping_portaddr_for_each_entry(sk, hnode, hslot) {
isk = inet_sk(sk);
pr_debug("iterate\n");
if (isk->inet_num != ident)
continue;
if (skb->protocol == htons(ETH_P_IP) &&
sk->sk_family == AF_INET) {
pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
(int) isk->inet_num, &isk->inet_rcv_saddr,
sk->sk_bound_dev_if);
if (isk->inet_rcv_saddr &&
isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
continue;
#if IS_ENABLED(CONFIG_IPV6)
} else if (skb->protocol == htons(ETH_P_IPV6) &&
sk->sk_family == AF_INET6) {
pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
(int) isk->inet_num,
&sk->sk_v6_rcv_saddr,
sk->sk_bound_dev_if);
if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
!ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
&ipv6_hdr(skb)->daddr))
continue;
#endif
} else {
continue;
}
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
continue;
sock_hold(sk);
goto exit;
}
sk = NULL;
exit:
read_unlock_bh(&ping_table.lock);
return sk;
}
static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
kgid_t *high)
{
kgid_t *data = net->ipv4.ping_group_range.range;
unsigned int seq;
do {
seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
*low = data[0];
*high = data[1];
} while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
}
int ping_init_sock(struct sock *sk)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
struct net *net = sock_net(sk);
kgid_t group = current_egid();
struct group_info *group_info;
cred: simpler, 1D supplementary groups Current supplementary groups code can massively overallocate memory and is implemented in a way so that access to individual gid is done via 2D array. If number of gids is <= 32, memory allocation is more or less tolerable (140/148 bytes). But if it is not, code allocates full page (!) regardless and, what's even more fun, doesn't reuse small 32-entry array. 2D array means dependent shifts, loads and LEAs without possibility to optimize them (gid is never known at compile time). All of the above is unnecessary. Switch to the usual trailing-zero-len-array scheme. Memory is allocated with kmalloc/vmalloc() and only as much as needed. Accesses become simpler (LEA 8(gi,idx,4) or even without displacement). Maximum number of gids is 65536 which translates to 256KB+8 bytes. I think kernel can handle such allocation. On my usual desktop system with whole 9 (nine) aux groups, struct group_info shrinks from 148 bytes to 44 bytes, yay! Nice side effects: - "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing, - fix little mess in net/ipv4/ping.c should have been using GROUP_AT macro but this point becomes moot, - aux group allocation is persistent and should be accounted as such. Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-08 00:03:12 +00:00
int i;
kgid_t low, high;
int ret = 0;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (sk->sk_family == AF_INET6)
sk->sk_ipv6only = 1;
inet_get_ping_group_range_net(net, &low, &high);
if (gid_lte(low, group) && gid_lte(group, high))
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
return 0;
group_info = get_current_groups();
cred: simpler, 1D supplementary groups Current supplementary groups code can massively overallocate memory and is implemented in a way so that access to individual gid is done via 2D array. If number of gids is <= 32, memory allocation is more or less tolerable (140/148 bytes). But if it is not, code allocates full page (!) regardless and, what's even more fun, doesn't reuse small 32-entry array. 2D array means dependent shifts, loads and LEAs without possibility to optimize them (gid is never known at compile time). All of the above is unnecessary. Switch to the usual trailing-zero-len-array scheme. Memory is allocated with kmalloc/vmalloc() and only as much as needed. Accesses become simpler (LEA 8(gi,idx,4) or even without displacement). Maximum number of gids is 65536 which translates to 256KB+8 bytes. I think kernel can handle such allocation. On my usual desktop system with whole 9 (nine) aux groups, struct group_info shrinks from 148 bytes to 44 bytes, yay! Nice side effects: - "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing, - fix little mess in net/ipv4/ping.c should have been using GROUP_AT macro but this point becomes moot, - aux group allocation is persistent and should be accounted as such. Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-08 00:03:12 +00:00
for (i = 0; i < group_info->ngroups; i++) {
kgid_t gid = group_info->gid[i];
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
cred: simpler, 1D supplementary groups Current supplementary groups code can massively overallocate memory and is implemented in a way so that access to individual gid is done via 2D array. If number of gids is <= 32, memory allocation is more or less tolerable (140/148 bytes). But if it is not, code allocates full page (!) regardless and, what's even more fun, doesn't reuse small 32-entry array. 2D array means dependent shifts, loads and LEAs without possibility to optimize them (gid is never known at compile time). All of the above is unnecessary. Switch to the usual trailing-zero-len-array scheme. Memory is allocated with kmalloc/vmalloc() and only as much as needed. Accesses become simpler (LEA 8(gi,idx,4) or even without displacement). Maximum number of gids is 65536 which translates to 256KB+8 bytes. I think kernel can handle such allocation. On my usual desktop system with whole 9 (nine) aux groups, struct group_info shrinks from 148 bytes to 44 bytes, yay! Nice side effects: - "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing, - fix little mess in net/ipv4/ping.c should have been using GROUP_AT macro but this point becomes moot, - aux group allocation is persistent and should be accounted as such. Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-08 00:03:12 +00:00
if (gid_lte(low, gid) && gid_lte(gid, high))
goto out_release_group;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
ret = -EACCES;
out_release_group:
put_group_info(group_info);
return ret;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
EXPORT_SYMBOL_GPL(ping_init_sock);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
void ping_close(struct sock *sk, long timeout)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
pr_debug("ping_close(sk=%p,sk->num=%u)\n",
inet_sk(sk), inet_sk(sk)->inet_num);
pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt));
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
sk_common_release(sk);
}
EXPORT_SYMBOL_GPL(ping_close);
/* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
struct sockaddr *uaddr, int addr_len)
{
struct net *net = sock_net(sk);
if (sk->sk_family == AF_INET) {
struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
int chk_addr_ret;
if (addr_len < sizeof(*addr))
return -EINVAL;
if (addr->sin_family != AF_INET &&
!(addr->sin_family == AF_UNSPEC &&
addr->sin_addr.s_addr == htonl(INADDR_ANY)))
return -EAFNOSUPPORT;
pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
chk_addr_ret = RTN_LOCAL;
else
chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
if ((!inet_can_nonlocal_bind(net, isk) &&
chk_addr_ret != RTN_LOCAL) ||
chk_addr_ret == RTN_MULTICAST ||
chk_addr_ret == RTN_BROADCAST)
return -EADDRNOTAVAIL;
#if IS_ENABLED(CONFIG_IPV6)
} else if (sk->sk_family == AF_INET6) {
struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
int addr_type, scoped, has_addr;
struct net_device *dev = NULL;
if (addr_len < sizeof(*addr))
return -EINVAL;
if (addr->sin6_family != AF_INET6)
return -EAFNOSUPPORT;
pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
addr_type = ipv6_addr_type(&addr->sin6_addr);
scoped = __ipv6_addr_needs_scope_id(addr_type);
if ((addr_type != IPV6_ADDR_ANY &&
!(addr_type & IPV6_ADDR_UNICAST)) ||
(scoped && !addr->sin6_scope_id))
return -EINVAL;
rcu_read_lock();
if (addr->sin6_scope_id) {
dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
if (!dev) {
rcu_read_unlock();
return -ENODEV;
}
}
has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
scoped);
rcu_read_unlock();
if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr ||
addr_type == IPV6_ADDR_ANY))
return -EADDRNOTAVAIL;
if (scoped)
sk->sk_bound_dev_if = addr->sin6_scope_id;
#endif
} else {
return -EAFNOSUPPORT;
}
return 0;
}
static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
{
if (saddr->sa_family == AF_INET) {
struct inet_sock *isk = inet_sk(sk);
struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
#if IS_ENABLED(CONFIG_IPV6)
} else if (saddr->sa_family == AF_INET6) {
struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
struct ipv6_pinfo *np = inet6_sk(sk);
sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
#endif
}
}
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
/*
* We need our own bind because there are no privileged id's == local ports.
* Moreover, we don't allow binding to multi- and broadcast addresses.
*/
int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
struct inet_sock *isk = inet_sk(sk);
unsigned short snum;
int err;
int dif = sk->sk_bound_dev_if;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
if (err)
return err;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
lock_sock(sk);
err = -EINVAL;
if (isk->inet_num != 0)
goto out;
err = -EADDRINUSE;
snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
if (ping_get_port(sk, snum) != 0) {
/* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */
sk->sk_bound_dev_if = dif;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
goto out;
}
ping_set_saddr(sk, uaddr);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
pr_debug("after bind(): num = %hu, dif = %d\n",
isk->inet_num,
sk->sk_bound_dev_if);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
err = 0;
if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
#if IS_ENABLED(CONFIG_IPV6)
if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
#endif
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (snum)
sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
isk->inet_sport = htons(isk->inet_num);
isk->inet_daddr = 0;
isk->inet_dport = 0;
#if IS_ENABLED(CONFIG_IPV6)
if (sk->sk_family == AF_INET6)
memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
#endif
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
sk_dst_reset(sk);
out:
release_sock(sk);
pr_debug("ping_v4_bind -> %d\n", err);
return err;
}
EXPORT_SYMBOL_GPL(ping_bind);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
/*
* Is this a supported type of ICMP message?
*/
static inline int ping_supported(int family, int type, int code)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
(family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
/*
* This routine is called by the ICMP module when it gets some
* sort of error condition.
*/
void ping_err(struct sk_buff *skb, int offset, u32 info)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
int family;
struct icmphdr *icmph;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
struct inet_sock *inet_sock;
int type;
int code;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
struct net *net = dev_net(skb->dev);
struct sock *sk;
int harderr;
int err;
if (skb->protocol == htons(ETH_P_IP)) {
family = AF_INET;
type = icmp_hdr(skb)->type;
code = icmp_hdr(skb)->code;
icmph = (struct icmphdr *)(skb->data + offset);
} else if (skb->protocol == htons(ETH_P_IPV6)) {
family = AF_INET6;
type = icmp6_hdr(skb)->icmp6_type;
code = icmp6_hdr(skb)->icmp6_code;
icmph = (struct icmphdr *) (skb->data + offset);
} else {
BUG();
}
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
/* We assume the packet has already been checked by icmp_unreach */
if (!ping_supported(family, icmph->type, icmph->code))
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
return;
pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
skb->protocol, type, code, ntohs(icmph->un.echo.id),
ntohs(icmph->un.echo.sequence));
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
if (!sk) {
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
pr_debug("no socket, dropping\n");
return; /* No socket for error */
}
pr_debug("err on socket %p\n", sk);
err = 0;
harderr = 0;
inet_sock = inet_sk(sk);
if (skb->protocol == htons(ETH_P_IP)) {
switch (type) {
default:
case ICMP_TIME_EXCEEDED:
err = EHOSTUNREACH;
break;
case ICMP_SOURCE_QUENCH:
/* This is not a real error but ping wants to see it.
* Report it with some fake errno.
*/
err = EREMOTEIO;
break;
case ICMP_PARAMETERPROB:
err = EPROTO;
harderr = 1;
break;
case ICMP_DEST_UNREACH:
if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
ipv4_sk_update_pmtu(skb, sk, info);
if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
err = EMSGSIZE;
harderr = 1;
break;
}
goto out;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
err = EHOSTUNREACH;
if (code <= NR_ICMP_UNREACH) {
harderr = icmp_err_convert[code].fatal;
err = icmp_err_convert[code].errno;
}
break;
case ICMP_REDIRECT:
/* See ICMP_SOURCE_QUENCH */
ipv4_sk_redirect(skb, sk);
err = EREMOTEIO;
break;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
#if IS_ENABLED(CONFIG_IPV6)
} else if (skb->protocol == htons(ETH_P_IPV6)) {
harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
#endif
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
/*
* RFC1122: OK. Passes ICMP errors back to application, as per
* 4.1.3.3.
*/
if ((family == AF_INET && !inet_sock->recverr) ||
(family == AF_INET6 && !inet6_sk(sk)->recverr)) {
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (!harderr || sk->sk_state != TCP_ESTABLISHED)
goto out;
} else {
if (family == AF_INET) {
ip_icmp_error(sk, skb, err, 0 /* no remote port */,
info, (u8 *)icmph);
#if IS_ENABLED(CONFIG_IPV6)
} else if (family == AF_INET6) {
pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
info, (u8 *)icmph);
#endif
}
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
sk->sk_err = err;
sk->sk_error_report(sk);
out:
sock_put(sk);
}
EXPORT_SYMBOL_GPL(ping_err);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
/*
* Copy and checksum an ICMP Echo packet from user space into a buffer
* starting from the payload.
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
*/
int ping_getfrag(void *from, char *to,
int offset, int fraglen, int odd, struct sk_buff *skb)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
struct pingfakehdr *pfh = (struct pingfakehdr *)from;
if (offset == 0) {
fraglen -= sizeof(struct icmphdr);
if (fraglen < 0)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
BUG();
if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr),
fraglen, &pfh->wcheck,
&pfh->msg->msg_iter))
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
return -EFAULT;
} else if (offset < sizeof(struct icmphdr)) {
BUG();
} else {
if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
&pfh->msg->msg_iter))
return -EFAULT;
}
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
#if IS_ENABLED(CONFIG_IPV6)
/* For IPv6, checksum each skb as we go along, as expected by
* icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
* wcheck, it will be finalized in ping_v4_push_pending_frames.
*/
if (pfh->family == AF_INET6) {
skb->csum = pfh->wcheck;
skb->ip_summed = CHECKSUM_NONE;
pfh->wcheck = 0;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
#endif
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
return 0;
}
EXPORT_SYMBOL_GPL(ping_getfrag);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
struct flowi4 *fl4)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
ping: fix a null pointer dereference Andrey reported a kernel crash: general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 2 PID: 3880 Comm: syz-executor1 Not tainted 4.10.0-rc6+ #124 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff880060048040 task.stack: ffff880069be8000 RIP: 0010:ping_v4_push_pending_frames net/ipv4/ping.c:647 [inline] RIP: 0010:ping_v4_sendmsg+0x1acd/0x23f0 net/ipv4/ping.c:837 RSP: 0018:ffff880069bef8b8 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffff880069befb90 RCX: 0000000000000000 RDX: 0000000000000018 RSI: ffff880069befa30 RDI: 00000000000000c2 RBP: ffff880069befbb8 R08: 0000000000000008 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: ffff880069befab0 R13: ffff88006c624a80 R14: ffff880069befa70 R15: 0000000000000000 FS: 00007f6f7c716700(0000) GS:ffff88006de00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004a6f28 CR3: 000000003a134000 CR4: 00000000000006e0 Call Trace: inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:744 sock_sendmsg_nosec net/socket.c:635 [inline] sock_sendmsg+0xca/0x110 net/socket.c:645 SYSC_sendto+0x660/0x810 net/socket.c:1687 SyS_sendto+0x40/0x50 net/socket.c:1655 entry_SYSCALL_64_fastpath+0x1f/0xc2 This is because we miss a check for NULL pointer for skb_peek() when the queue is empty. Other places already have the same check. Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-07 20:59:46 +00:00
if (!skb)
return 0;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
pfh->wcheck = csum_partial((char *)&pfh->icmph,
sizeof(struct icmphdr), pfh->wcheck);
pfh->icmph.checksum = csum_fold(pfh->wcheck);
memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
skb->ip_summed = CHECKSUM_NONE;
return ip_push_pending_frames(sk, fl4);
}
int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
void *user_icmph, size_t icmph_len)
{
u8 type, code;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (len > 0xFFFF)
return -EMSGSIZE;
net: ping: check minimum size on ICMP header length Prior to commit c0371da6047a ("put iov_iter into msghdr") in v3.19, there was no check that the iovec contained enough bytes for an ICMP header, and the read loop would walk across neighboring stack contents. Since the iov_iter conversion, bad arguments are noticed, but the returned error is EFAULT. Returning EINVAL is a clearer error and also solves the problem prior to v3.19. This was found using trinity with KASAN on v3.18: BUG: KASAN: stack-out-of-bounds in memcpy_fromiovec+0x60/0x114 at addr ffffffc071077da0 Read of size 8 by task trinity-c2/9623 page:ffffffbe034b9a08 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x0() page dumped because: kasan: bad access detected CPU: 0 PID: 9623 Comm: trinity-c2 Tainted: G BU 3.18.0-dirty #15 Hardware name: Google Tegra210 Smaug Rev 1,3+ (DT) Call trace: [<ffffffc000209c98>] dump_backtrace+0x0/0x1ac arch/arm64/kernel/traps.c:90 [<ffffffc000209e54>] show_stack+0x10/0x1c arch/arm64/kernel/traps.c:171 [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffc000f18dc4>] dump_stack+0x7c/0xd0 lib/dump_stack.c:50 [< inline >] print_address_description mm/kasan/report.c:147 [< inline >] kasan_report_error mm/kasan/report.c:236 [<ffffffc000373dcc>] kasan_report+0x380/0x4b8 mm/kasan/report.c:259 [< inline >] check_memory_region mm/kasan/kasan.c:264 [<ffffffc00037352c>] __asan_load8+0x20/0x70 mm/kasan/kasan.c:507 [<ffffffc0005b9624>] memcpy_fromiovec+0x5c/0x114 lib/iovec.c:15 [< inline >] memcpy_from_msg include/linux/skbuff.h:2667 [<ffffffc000ddeba0>] ping_common_sendmsg+0x50/0x108 net/ipv4/ping.c:674 [<ffffffc000dded30>] ping_v4_sendmsg+0xd8/0x698 net/ipv4/ping.c:714 [<ffffffc000dc91dc>] inet_sendmsg+0xe0/0x12c net/ipv4/af_inet.c:749 [< inline >] __sock_sendmsg_nosec net/socket.c:624 [< inline >] __sock_sendmsg net/socket.c:632 [<ffffffc000cab61c>] sock_sendmsg+0x124/0x164 net/socket.c:643 [< inline >] SYSC_sendto net/socket.c:1797 [<ffffffc000cad270>] SyS_sendto+0x178/0x1d8 net/socket.c:1761 CVE-2016-8399 Reported-by: Qidan He <i@flanker017.me> Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-05 18:34:38 +00:00
/* Must have at least a full ICMP header. */
if (len < icmph_len)
return -EINVAL;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
/*
* Check the flags.
*/
/* Mirror BSD error message compatibility */
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;
/*
* Fetch the ICMP header provided by the userland.
* iovec is modified! The ICMP header is consumed.
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
*/
if (memcpy_from_msg(user_icmph, msg, icmph_len))
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
return -EFAULT;
if (family == AF_INET) {
type = ((struct icmphdr *) user_icmph)->type;
code = ((struct icmphdr *) user_icmph)->code;
#if IS_ENABLED(CONFIG_IPV6)
} else if (family == AF_INET6) {
type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
#endif
} else {
BUG();
}
if (!ping_supported(family, type, code))
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
return -EINVAL;
return 0;
}
EXPORT_SYMBOL_GPL(ping_common_sendmsg);
static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
{
struct net *net = sock_net(sk);
struct flowi4 fl4;
struct inet_sock *inet = inet_sk(sk);
struct ipcm_cookie ipc;
struct icmphdr user_icmph;
struct pingfakehdr pfh;
struct rtable *rt = NULL;
struct ip_options_data opt_copy;
int free = 0;
__be32 saddr, daddr, faddr;
u8 tos;
int err;
pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
sizeof(user_icmph));
if (err)
return err;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
/*
* Get and verify the address.
*/
if (msg->msg_name) {
DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (msg->msg_namelen < sizeof(*usin))
return -EINVAL;
if (usin->sin_family != AF_INET)
return -EAFNOSUPPORT;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
daddr = usin->sin_addr.s_addr;
/* no remote port */
} else {
if (sk->sk_state != TCP_ESTABLISHED)
return -EDESTADDRREQ;
daddr = inet->inet_daddr;
/* no remote port */
}
ipcm_init_sk(&ipc, inet);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (msg->msg_controllen) {
err = ip_cmsg_send(sk, msg, &ipc, false);
if (unlikely(err)) {
kfree(ipc.opt);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
return err;
}
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (ipc.opt)
free = 1;
}
if (!ipc.opt) {
struct ip_options_rcu *inet_opt;
rcu_read_lock();
inet_opt = rcu_dereference(inet->inet_opt);
if (inet_opt) {
memcpy(&opt_copy, inet_opt,
sizeof(*inet_opt) + inet_opt->opt.optlen);
ipc.opt = &opt_copy.opt;
}
rcu_read_unlock();
}
saddr = ipc.addr;
ipc.addr = faddr = daddr;
if (ipc.opt && ipc.opt->opt.srr) {
if (!daddr) {
err = -EINVAL;
goto out_free;
}
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
faddr = ipc.opt->opt.faddr;
}
tos = get_rttos(&ipc, inet);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (sock_flag(sk, SOCK_LOCALROUTE) ||
(msg->msg_flags & MSG_DONTROUTE) ||
(ipc.opt && ipc.opt->opt.is_strictroute)) {
tos |= RTO_ONLINK;
}
if (ipv4_is_multicast(daddr)) {
if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
ipc.oif = inet->mc_index;
if (!saddr)
saddr = inet->mc_addr;
ipv4: Implement IP_UNICAST_IF socket option. The IP_UNICAST_IF feature is needed by the Wine project. This patch implements the feature by setting the outgoing interface in a similar fashion to that of IP_MULTICAST_IF. A separate option is needed to handle this feature since the existing options do not provide all of the characteristics required by IP_UNICAST_IF, a summary is provided below. SO_BINDTODEVICE: * SO_BINDTODEVICE requires administrative privileges, IP_UNICAST_IF does not. From reading some old mailing list articles my understanding is that SO_BINDTODEVICE requires administrative privileges because it can override the administrator's routing settings. * The SO_BINDTODEVICE option restricts both outbound and inbound traffic, IP_UNICAST_IF only impacts outbound traffic. IP_PKTINFO: * Since IP_PKTINFO and IP_UNICAST_IF are independent options, implementing IP_UNICAST_IF with IP_PKTINFO will likely break some applications. * Implementing IP_UNICAST_IF on top of IP_PKTINFO significantly complicates the Wine codebase and reduces the socket performance (doing this requires a lot of extra communication between the "server" and "user" layers). bind(): * bind() does not work on broadcast packets, IP_UNICAST_IF is specifically intended to work with broadcast packets. * Like SO_BINDTODEVICE, bind() restricts both outbound and inbound traffic. Signed-off-by: Erich E. Hoover <ehoover@mines.edu> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-08 09:11:07 +00:00
} else if (!ipc.oif)
ipc.oif = inet->uc_index;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos,
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
RT_SCOPE_UNIVERSE, sk->sk_protocol,
inet_sk_flowi_flags(sk), faddr, saddr, 0, 0,
sk->sk_uid);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
fl4.fl4_icmp_type = user_icmph.type;
fl4.fl4_icmp_code = user_icmph.code;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
rt = ip_route_output_flow(net, &fl4, sk);
if (IS_ERR(rt)) {
err = PTR_ERR(rt);
rt = NULL;
if (err == -ENETUNREACH)
IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
goto out;
}
err = -EACCES;
if ((rt->rt_flags & RTCF_BROADCAST) &&
!sock_flag(sk, SOCK_BROADCAST))
goto out;
if (msg->msg_flags & MSG_CONFIRM)
goto do_confirm;
back_from_confirm:
if (!ipc.addr)
ipc.addr = fl4.daddr;
lock_sock(sk);
pfh.icmph.type = user_icmph.type; /* already checked */
pfh.icmph.code = user_icmph.code; /* ditto */
pfh.icmph.checksum = 0;
pfh.icmph.un.echo.id = inet->inet_sport;
pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
pfh.msg = msg;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
pfh.wcheck = 0;
pfh.family = AF_INET;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
0, &ipc, &rt, msg->msg_flags);
if (err)
ip_flush_pending_frames(sk);
else
err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
release_sock(sk);
out:
ip_rt_put(rt);
out_free:
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (free)
kfree(ipc.opt);
if (!err) {
icmp_out_count(sock_net(sk), user_icmph.type);
return len;
}
return err;
do_confirm:
if (msg->msg_flags & MSG_PROBE)
dst_confirm_neigh(&rt->dst, &fl4.daddr);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (!(msg->msg_flags & MSG_PROBE) || len)
goto back_from_confirm;
err = 0;
goto out;
}
int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
int flags, int *addr_len)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
struct inet_sock *isk = inet_sk(sk);
int family = sk->sk_family;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
struct sk_buff *skb;
int copied, err;
pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
err = -EOPNOTSUPP;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (flags & MSG_OOB)
goto out;
if (flags & MSG_ERRQUEUE)
return inet_recv_error(sk, msg, len, addr_len);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
skb = skb_recv_datagram(sk, flags, noblock, &err);
if (!skb)
goto out;
copied = skb->len;
if (copied > len) {
msg->msg_flags |= MSG_TRUNC;
copied = len;
}
/* Don't bother checking the checksum */
err = skb_copy_datagram_msg(skb, 0, msg, copied);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (err)
goto done;
sock_recv_timestamp(msg, sk, skb);
/* Copy the address and add cmsg data. */
if (family == AF_INET) {
DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
if (sin) {
sin->sin_family = AF_INET;
sin->sin_port = 0 /* skb->h.uh->source */;
sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
*addr_len = sizeof(*sin);
}
if (isk->cmsg_flags)
ip_cmsg_recv(msg, skb);
#if IS_ENABLED(CONFIG_IPV6)
} else if (family == AF_INET6) {
struct ipv6_pinfo *np = inet6_sk(sk);
struct ipv6hdr *ip6 = ipv6_hdr(skb);
DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
if (sin6) {
sin6->sin6_family = AF_INET6;
sin6->sin6_port = 0;
sin6->sin6_addr = ip6->saddr;
sin6->sin6_flowinfo = 0;
if (np->sndflow)
sin6->sin6_flowinfo = ip6_flowinfo(ip6);
sin6->sin6_scope_id =
ipv6_iface_scope_id(&sin6->sin6_addr,
inet6_iif(skb));
*addr_len = sizeof(*sin6);
}
if (inet6_sk(sk)->rxopt.all)
pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
if (skb->protocol == htons(ETH_P_IPV6) &&
inet6_sk(sk)->rxopt.all)
pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
ip_cmsg_recv(msg, skb);
#endif
} else {
BUG();
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
err = copied;
done:
skb_free_datagram(sk, skb);
out:
pr_debug("ping_recvmsg -> %d\n", err);
return err;
}
EXPORT_SYMBOL_GPL(ping_recvmsg);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
inet_sk(sk), inet_sk(sk)->inet_num, skb);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (sock_queue_rcv_skb(sk, skb) < 0) {
kfree_skb(skb);
pr_debug("ping_queue_rcv_skb -> failed\n");
return -1;
}
return 0;
}
EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
/*
* All we need to do is get the socket.
*/
bool ping_rcv(struct sk_buff *skb)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
struct sock *sk;
struct net *net = dev_net(skb->dev);
struct icmphdr *icmph = icmp_hdr(skb);
/* We assume the packet has already been checked by icmp_rcv */
pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
/* Push ICMP header back */
skb_push(skb, skb->data - (u8 *)icmph);
sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
if (sk) {
struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
pr_debug("rcv on socket %p\n", sk);
if (skb2)
ping_queue_rcv_skb(sk, skb2);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
sock_put(sk);
return true;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
pr_debug("no socket, dropping\n");
return false;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
EXPORT_SYMBOL_GPL(ping_rcv);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
struct proto ping_prot = {
.name = "PING",
.owner = THIS_MODULE,
.init = ping_init_sock,
.close = ping_close,
.connect = ip4_datagram_connect,
.disconnect = __udp_disconnect,
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
.setsockopt = ip_setsockopt,
.getsockopt = ip_getsockopt,
.sendmsg = ping_v4_sendmsg,
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
.recvmsg = ping_recvmsg,
.bind = ping_bind,
.backlog_rcv = ping_queue_rcv_skb,
.release_cb = ip4_datagram_release_cb,
.hash = ping_hash,
.unhash = ping_unhash,
.get_port = ping_get_port,
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
.obj_size = sizeof(struct inet_sock),
};
EXPORT_SYMBOL(ping_prot);
#ifdef CONFIG_PROC_FS
static struct sock *ping_get_first(struct seq_file *seq, int start)
{
struct sock *sk;
struct ping_iter_state *state = seq->private;
struct net *net = seq_file_net(seq);
for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
++state->bucket) {
struct hlist_nulls_node *node;
struct hlist_nulls_head *hslot;
hslot = &ping_table.hash[state->bucket];
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (hlist_nulls_empty(hslot))
continue;
sk_nulls_for_each(sk, node, hslot) {
if (net_eq(sock_net(sk), net) &&
sk->sk_family == state->family)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
goto found;
}
}
sk = NULL;
found:
return sk;
}
static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
{
struct ping_iter_state *state = seq->private;
struct net *net = seq_file_net(seq);
do {
sk = sk_nulls_next(sk);
} while (sk && (!net_eq(sock_net(sk), net)));
if (!sk)
return ping_get_first(seq, state->bucket + 1);
return sk;
}
static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
{
struct sock *sk = ping_get_first(seq, 0);
if (sk)
while (pos && (sk = ping_get_next(seq, sk)) != NULL)
--pos;
return pos ? NULL : sk;
}
void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
__acquires(ping_table.lock)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
struct ping_iter_state *state = seq->private;
state->bucket = 0;
state->family = family;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
read_lock_bh(&ping_table.lock);
return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
}
EXPORT_SYMBOL_GPL(ping_seq_start);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
{
return ping_seq_start(seq, pos, AF_INET);
}
void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
struct sock *sk;
if (v == SEQ_START_TOKEN)
sk = ping_get_idx(seq, 0);
else
sk = ping_get_next(seq, v);
++*pos;
return sk;
}
EXPORT_SYMBOL_GPL(ping_seq_next);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
void ping_seq_stop(struct seq_file *seq, void *v)
__releases(ping_table.lock)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
read_unlock_bh(&ping_table.lock);
}
EXPORT_SYMBOL_GPL(ping_seq_stop);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
int bucket)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
struct inet_sock *inet = inet_sk(sp);
__be32 dest = inet->inet_daddr;
__be32 src = inet->inet_rcv_saddr;
__u16 destp = ntohs(inet->inet_dport);
__u16 srcp = ntohs(inet->inet_sport);
seq_printf(f, "%5d: %08X:%04X %08X:%04X"
" %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
bucket, src, srcp, dest, destp, sp->sk_state,
sk_wmem_alloc_get(sp),
sk_rmem_alloc_get(sp),
0, 0L, 0,
from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
0, sock_i_ino(sp),
refcount_read(&sp->sk_refcnt), sp,
atomic_read(&sp->sk_drops));
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
static int ping_v4_seq_show(struct seq_file *seq, void *v)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
seq_setwidth(seq, 127);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
if (v == SEQ_START_TOKEN)
seq_puts(seq, " sl local_address rem_address st tx_queue "
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
"rx_queue tr tm->when retrnsmt uid timeout "
"inode ref pointer drops");
else {
struct ping_iter_state *state = seq->private;
ping_v4_format_sock(v, seq, state->bucket);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
seq_pad(seq, '\n');
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
return 0;
}
static const struct seq_operations ping_v4_seq_ops = {
.start = ping_v4_seq_start,
.show = ping_v4_seq_show,
.next = ping_seq_next,
.stop = ping_seq_stop,
};
static int __net_init ping_v4_proc_init_net(struct net *net)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
sizeof(struct ping_iter_state)))
return -ENOMEM;
return 0;
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
static void __net_exit ping_v4_proc_exit_net(struct net *net)
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
{
remove_proc_entry("icmp", net->proc_net);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
static struct pernet_operations ping_v4_net_ops = {
.init = ping_v4_proc_init_net,
.exit = ping_v4_proc_exit_net,
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
};
int __init ping_proc_init(void)
{
return register_pernet_subsys(&ping_v4_net_ops);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
void ping_proc_exit(void)
{
unregister_pernet_subsys(&ping_v4_net_ops);
net: ipv4: add IPPROTO_ICMP socket kind This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 10:01:00 +00:00
}
#endif
void __init ping_init(void)
{
int i;
for (i = 0; i < PING_HTABLE_SIZE; i++)
INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
rwlock_init(&ping_table.lock);
}