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linux/net/l2tp/l2tp_netlink.c
Matthias Schiffer 3e59e88567 net: l2tp: reduce log level of messages in receive path, add counter instead 
Commit 5ee759cda5 ("l2tp: use standard API for warning log messages")
changed a number of warnings about invalid packets in the receive path
so that they are always shown, instead of only when a special L2TP debug
flag is set. Even with rate limiting these warnings can easily cause
significant log spam - potentially triggered by a malicious party
sending invalid packets on purpose.

In addition these warnings were noticed by projects like Tunneldigger [1],
which uses L2TP for its data path, but implements its own control
protocol (which is sufficiently different from L2TP data packets that it
would always be passed up to userspace even with future extensions of
L2TP).

Some of the warnings were already redundant, as l2tp_stats has a counter
for these packets. This commit adds one additional counter for invalid
packets that are passed up to userspace. Packets with unknown session are
not counted as invalid, as there is nothing wrong with the format of
these packets.

With the additional counter, all of these messages are either redundant
or benign, so we reduce them to pr_debug_ratelimited().

[1] https://github.com/wlanslovenija/tunneldigger/issues/160

Fixes: 5ee759cda5 ("l2tp: use standard API for warning log messages")
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-03 16:55:02 -08:00

1048 lines
27 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0-only
/* L2TP netlink layer, for management
*
* Copyright (c) 2008,2009,2010 Katalix Systems Ltd
*
* Partly based on the IrDA nelink implementation
* (see net/irda/irnetlink.c) which is:
* Copyright (c) 2007 Samuel Ortiz <samuel@sortiz.org>
* which is in turn partly based on the wireless netlink code:
* Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <net/sock.h>
#include <net/genetlink.h>
#include <net/udp.h>
#include <linux/in.h>
#include <linux/udp.h>
#include <linux/socket.h>
#include <linux/module.h>
#include <linux/list.h>
#include <net/net_namespace.h>
#include <linux/l2tp.h>
#include "l2tp_core.h"
static struct genl_family l2tp_nl_family;
static const struct genl_multicast_group l2tp_multicast_group[] = {
{
.name = L2TP_GENL_MCGROUP,
},
};
static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq,
int flags, struct l2tp_tunnel *tunnel, u8 cmd);
static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq,
int flags, struct l2tp_session *session,
u8 cmd);
/* Accessed under genl lock */
static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
static struct l2tp_session *l2tp_nl_session_get(struct genl_info *info)
{
u32 tunnel_id;
u32 session_id;
char *ifname;
struct l2tp_tunnel *tunnel;
struct l2tp_session *session = NULL;
struct net *net = genl_info_net(info);
if (info->attrs[L2TP_ATTR_IFNAME]) {
ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
session = l2tp_session_get_by_ifname(net, ifname);
} else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
(info->attrs[L2TP_ATTR_CONN_ID])) {
tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
tunnel = l2tp_tunnel_get(net, tunnel_id);
if (tunnel) {
session = l2tp_tunnel_get_session(tunnel, session_id);
l2tp_tunnel_dec_refcount(tunnel);
}
}
return session;
}
static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
{
struct sk_buff *msg;
void *hdr;
int ret = -ENOBUFS;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg) {
ret = -ENOMEM;
goto out;
}
hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
&l2tp_nl_family, 0, L2TP_CMD_NOOP);
if (!hdr) {
ret = -EMSGSIZE;
goto err_out;
}
genlmsg_end(msg, hdr);
return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
err_out:
nlmsg_free(msg);
out:
return ret;
}
static int l2tp_tunnel_notify(struct genl_family *family,
struct genl_info *info,
struct l2tp_tunnel *tunnel,
u8 cmd)
{
struct sk_buff *msg;
int ret;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
NLM_F_ACK, tunnel, cmd);
if (ret >= 0) {
ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
/* We don't care if no one is listening */
if (ret == -ESRCH)
ret = 0;
return ret;
}
nlmsg_free(msg);
return ret;
}
static int l2tp_session_notify(struct genl_family *family,
struct genl_info *info,
struct l2tp_session *session,
u8 cmd)
{
struct sk_buff *msg;
int ret;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
NLM_F_ACK, session, cmd);
if (ret >= 0) {
ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
/* We don't care if no one is listening */
if (ret == -ESRCH)
ret = 0;
return ret;
}
nlmsg_free(msg);
return ret;
}
static int l2tp_nl_cmd_tunnel_create_get_addr(struct nlattr **attrs, struct l2tp_tunnel_cfg *cfg)
{
if (attrs[L2TP_ATTR_UDP_SPORT])
cfg->local_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_SPORT]);
if (attrs[L2TP_ATTR_UDP_DPORT])
cfg->peer_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_DPORT]);
cfg->use_udp_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_CSUM]);
/* Must have either AF_INET or AF_INET6 address for source and destination */
#if IS_ENABLED(CONFIG_IPV6)
if (attrs[L2TP_ATTR_IP6_SADDR] && attrs[L2TP_ATTR_IP6_DADDR]) {
cfg->local_ip6 = nla_data(attrs[L2TP_ATTR_IP6_SADDR]);
cfg->peer_ip6 = nla_data(attrs[L2TP_ATTR_IP6_DADDR]);
cfg->udp6_zero_tx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
cfg->udp6_zero_rx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
return 0;
}
#endif
if (attrs[L2TP_ATTR_IP_SADDR] && attrs[L2TP_ATTR_IP_DADDR]) {
cfg->local_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_SADDR]);
cfg->peer_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_DADDR]);
return 0;
}
return -EINVAL;
}
static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
{
u32 tunnel_id;
u32 peer_tunnel_id;
int proto_version;
int fd = -1;
int ret = 0;
struct l2tp_tunnel_cfg cfg = { 0, };
struct l2tp_tunnel *tunnel;
struct net *net = genl_info_net(info);
struct nlattr **attrs = info->attrs;
if (!attrs[L2TP_ATTR_CONN_ID]) {
ret = -EINVAL;
goto out;
}
tunnel_id = nla_get_u32(attrs[L2TP_ATTR_CONN_ID]);
if (!attrs[L2TP_ATTR_PEER_CONN_ID]) {
ret = -EINVAL;
goto out;
}
peer_tunnel_id = nla_get_u32(attrs[L2TP_ATTR_PEER_CONN_ID]);
if (!attrs[L2TP_ATTR_PROTO_VERSION]) {
ret = -EINVAL;
goto out;
}
proto_version = nla_get_u8(attrs[L2TP_ATTR_PROTO_VERSION]);
if (!attrs[L2TP_ATTR_ENCAP_TYPE]) {
ret = -EINVAL;
goto out;
}
cfg.encap = nla_get_u16(attrs[L2TP_ATTR_ENCAP_TYPE]);
/* Managed tunnels take the tunnel socket from userspace.
* Unmanaged tunnels must call out the source and destination addresses
* for the kernel to create the tunnel socket itself.
*/
if (attrs[L2TP_ATTR_FD]) {
fd = nla_get_u32(attrs[L2TP_ATTR_FD]);
} else {
ret = l2tp_nl_cmd_tunnel_create_get_addr(attrs, &cfg);
if (ret < 0)
goto out;
}
ret = -EINVAL;
switch (cfg.encap) {
case L2TP_ENCAPTYPE_UDP:
case L2TP_ENCAPTYPE_IP:
ret = l2tp_tunnel_create(fd, proto_version, tunnel_id,
peer_tunnel_id, &cfg, &tunnel);
break;
}
if (ret < 0)
goto out;
l2tp_tunnel_inc_refcount(tunnel);
ret = l2tp_tunnel_register(tunnel, net, &cfg);
if (ret < 0) {
kfree(tunnel);
goto out;
}
ret = l2tp_tunnel_notify(&l2tp_nl_family, info, tunnel,
L2TP_CMD_TUNNEL_CREATE);
l2tp_tunnel_dec_refcount(tunnel);
out:
return ret;
}
static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
{
struct l2tp_tunnel *tunnel;
u32 tunnel_id;
int ret = 0;
struct net *net = genl_info_net(info);
if (!info->attrs[L2TP_ATTR_CONN_ID]) {
ret = -EINVAL;
goto out;
}
tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
tunnel = l2tp_tunnel_get(net, tunnel_id);
if (!tunnel) {
ret = -ENODEV;
goto out;
}
l2tp_tunnel_notify(&l2tp_nl_family, info,
tunnel, L2TP_CMD_TUNNEL_DELETE);
l2tp_tunnel_delete(tunnel);
l2tp_tunnel_dec_refcount(tunnel);
out:
return ret;
}
static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
{
struct l2tp_tunnel *tunnel;
u32 tunnel_id;
int ret = 0;
struct net *net = genl_info_net(info);
if (!info->attrs[L2TP_ATTR_CONN_ID]) {
ret = -EINVAL;
goto out;
}
tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
tunnel = l2tp_tunnel_get(net, tunnel_id);
if (!tunnel) {
ret = -ENODEV;
goto out;
}
ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
tunnel, L2TP_CMD_TUNNEL_MODIFY);
l2tp_tunnel_dec_refcount(tunnel);
out:
return ret;
}
#if IS_ENABLED(CONFIG_IPV6)
static int l2tp_nl_tunnel_send_addr6(struct sk_buff *skb, struct sock *sk,
enum l2tp_encap_type encap)
{
struct inet_sock *inet = inet_sk(sk);
struct ipv6_pinfo *np = inet6_sk(sk);
switch (encap) {
case L2TP_ENCAPTYPE_UDP:
if (udp_get_no_check6_tx(sk) &&
nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
return -1;
if (udp_get_no_check6_rx(sk) &&
nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
return -1;
if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
return -1;
fallthrough;
case L2TP_ENCAPTYPE_IP:
if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR, &np->saddr) ||
nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR, &sk->sk_v6_daddr))
return -1;
break;
}
return 0;
}
#endif
static int l2tp_nl_tunnel_send_addr4(struct sk_buff *skb, struct sock *sk,
enum l2tp_encap_type encap)
{
struct inet_sock *inet = inet_sk(sk);
switch (encap) {
case L2TP_ENCAPTYPE_UDP:
if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx) ||
nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
return -1;
fallthrough;
case L2TP_ENCAPTYPE_IP:
if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) ||
nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr))
return -1;
break;
}
return 0;
}
/* Append attributes for the tunnel address, handling the different attribute types
* used for different tunnel encapsulation and AF_INET v.s. AF_INET6.
*/
static int l2tp_nl_tunnel_send_addr(struct sk_buff *skb, struct l2tp_tunnel *tunnel)
{
struct sock *sk = tunnel->sock;
if (!sk)
return 0;
#if IS_ENABLED(CONFIG_IPV6)
if (sk->sk_family == AF_INET6)
return l2tp_nl_tunnel_send_addr6(skb, sk, tunnel->encap);
#endif
return l2tp_nl_tunnel_send_addr4(skb, sk, tunnel->encap);
}
static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
struct l2tp_tunnel *tunnel, u8 cmd)
{
void *hdr;
struct nlattr *nest;
hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
if (!hdr)
return -EMSGSIZE;
if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
nla_put_u32(skb, L2TP_ATTR_DEBUG, 0) ||
nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
goto nla_put_failure;
nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
if (!nest)
goto nla_put_failure;
if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
atomic_long_read(&tunnel->stats.tx_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
atomic_long_read(&tunnel->stats.tx_bytes),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
atomic_long_read(&tunnel->stats.tx_errors),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
atomic_long_read(&tunnel->stats.rx_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
atomic_long_read(&tunnel->stats.rx_bytes),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
atomic_long_read(&tunnel->stats.rx_seq_discards),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_COOKIE_DISCARDS,
atomic_long_read(&tunnel->stats.rx_cookie_discards),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
atomic_long_read(&tunnel->stats.rx_oos_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
atomic_long_read(&tunnel->stats.rx_errors),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_INVALID,
atomic_long_read(&tunnel->stats.rx_invalid),
L2TP_ATTR_STATS_PAD))
goto nla_put_failure;
nla_nest_end(skb, nest);
if (l2tp_nl_tunnel_send_addr(skb, tunnel))
goto nla_put_failure;
genlmsg_end(skb, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(skb, hdr);
return -1;
}
static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
{
struct l2tp_tunnel *tunnel;
struct sk_buff *msg;
u32 tunnel_id;
int ret = -ENOBUFS;
struct net *net = genl_info_net(info);
if (!info->attrs[L2TP_ATTR_CONN_ID]) {
ret = -EINVAL;
goto err;
}
tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg) {
ret = -ENOMEM;
goto err;
}
tunnel = l2tp_tunnel_get(net, tunnel_id);
if (!tunnel) {
ret = -ENODEV;
goto err_nlmsg;
}
ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
if (ret < 0)
goto err_nlmsg_tunnel;
l2tp_tunnel_dec_refcount(tunnel);
return genlmsg_unicast(net, msg, info->snd_portid);
err_nlmsg_tunnel:
l2tp_tunnel_dec_refcount(tunnel);
err_nlmsg:
nlmsg_free(msg);
err:
return ret;
}
static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
int ti = cb->args[0];
struct l2tp_tunnel *tunnel;
struct net *net = sock_net(skb->sk);
for (;;) {
tunnel = l2tp_tunnel_get_nth(net, ti);
if (!tunnel)
goto out;
if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
tunnel, L2TP_CMD_TUNNEL_GET) < 0) {
l2tp_tunnel_dec_refcount(tunnel);
goto out;
}
l2tp_tunnel_dec_refcount(tunnel);
ti++;
}
out:
cb->args[0] = ti;
return skb->len;
}
static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
{
u32 tunnel_id = 0;
u32 session_id;
u32 peer_session_id;
int ret = 0;
struct l2tp_tunnel *tunnel;
struct l2tp_session *session;
struct l2tp_session_cfg cfg = { 0, };
struct net *net = genl_info_net(info);
if (!info->attrs[L2TP_ATTR_CONN_ID]) {
ret = -EINVAL;
goto out;
}
tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
tunnel = l2tp_tunnel_get(net, tunnel_id);
if (!tunnel) {
ret = -ENODEV;
goto out;
}
if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
ret = -EINVAL;
goto out_tunnel;
}
session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
ret = -EINVAL;
goto out_tunnel;
}
peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
ret = -EINVAL;
goto out_tunnel;
}
cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
ret = -EINVAL;
goto out_tunnel;
}
/* L2TPv2 only accepts PPP pseudo-wires */
if (tunnel->version == 2 && cfg.pw_type != L2TP_PWTYPE_PPP) {
ret = -EPROTONOSUPPORT;
goto out_tunnel;
}
if (tunnel->version > 2) {
if (info->attrs[L2TP_ATTR_L2SPEC_TYPE]) {
cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
if (cfg.l2specific_type != L2TP_L2SPECTYPE_DEFAULT &&
cfg.l2specific_type != L2TP_L2SPECTYPE_NONE) {
ret = -EINVAL;
goto out_tunnel;
}
} else {
cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
}
if (info->attrs[L2TP_ATTR_COOKIE]) {
u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
if (len > 8) {
ret = -EINVAL;
goto out_tunnel;
}
cfg.cookie_len = len;
memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
}
if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
if (len > 8) {
ret = -EINVAL;
goto out_tunnel;
}
cfg.peer_cookie_len = len;
memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
}
if (info->attrs[L2TP_ATTR_IFNAME])
cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
}
if (info->attrs[L2TP_ATTR_RECV_SEQ])
cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
if (info->attrs[L2TP_ATTR_SEND_SEQ])
cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
if (info->attrs[L2TP_ATTR_LNS_MODE])
cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
#ifdef CONFIG_MODULES
if (!l2tp_nl_cmd_ops[cfg.pw_type]) {
genl_unlock();
request_module("net-l2tp-type-%u", cfg.pw_type);
genl_lock();
}
#endif
if (!l2tp_nl_cmd_ops[cfg.pw_type] || !l2tp_nl_cmd_ops[cfg.pw_type]->session_create) {
ret = -EPROTONOSUPPORT;
goto out_tunnel;
}
ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
session_id,
peer_session_id,
&cfg);
if (ret >= 0) {
session = l2tp_tunnel_get_session(tunnel, session_id);
if (session) {
ret = l2tp_session_notify(&l2tp_nl_family, info, session,
L2TP_CMD_SESSION_CREATE);
l2tp_session_dec_refcount(session);
}
}
out_tunnel:
l2tp_tunnel_dec_refcount(tunnel);
out:
return ret;
}
static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
{
int ret = 0;
struct l2tp_session *session;
u16 pw_type;
session = l2tp_nl_session_get(info);
if (!session) {
ret = -ENODEV;
goto out;
}
l2tp_session_notify(&l2tp_nl_family, info,
session, L2TP_CMD_SESSION_DELETE);
pw_type = session->pwtype;
if (pw_type < __L2TP_PWTYPE_MAX)
if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
l2tp_nl_cmd_ops[pw_type]->session_delete(session);
l2tp_session_dec_refcount(session);
out:
return ret;
}
static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
{
int ret = 0;
struct l2tp_session *session;
session = l2tp_nl_session_get(info);
if (!session) {
ret = -ENODEV;
goto out;
}
if (info->attrs[L2TP_ATTR_RECV_SEQ])
session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
l2tp_session_set_header_len(session, session->tunnel->version);
}
if (info->attrs[L2TP_ATTR_LNS_MODE])
session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
ret = l2tp_session_notify(&l2tp_nl_family, info,
session, L2TP_CMD_SESSION_MODIFY);
l2tp_session_dec_refcount(session);
out:
return ret;
}
static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
struct l2tp_session *session, u8 cmd)
{
void *hdr;
struct nlattr *nest;
struct l2tp_tunnel *tunnel = session->tunnel;
hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
if (!hdr)
return -EMSGSIZE;
if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID, session->peer_session_id) ||
nla_put_u32(skb, L2TP_ATTR_DEBUG, 0) ||
nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype))
goto nla_put_failure;
if ((session->ifname[0] &&
nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
(session->cookie_len &&
nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len, session->cookie)) ||
(session->peer_cookie_len &&
nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len, session->peer_cookie)) ||
nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
(l2tp_tunnel_uses_xfrm(tunnel) &&
nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
(session->reorder_timeout &&
nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
session->reorder_timeout, L2TP_ATTR_PAD)))
goto nla_put_failure;
nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
if (!nest)
goto nla_put_failure;
if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
atomic_long_read(&session->stats.tx_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
atomic_long_read(&session->stats.tx_bytes),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
atomic_long_read(&session->stats.tx_errors),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
atomic_long_read(&session->stats.rx_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
atomic_long_read(&session->stats.rx_bytes),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
atomic_long_read(&session->stats.rx_seq_discards),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_COOKIE_DISCARDS,
atomic_long_read(&session->stats.rx_cookie_discards),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
atomic_long_read(&session->stats.rx_oos_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
atomic_long_read(&session->stats.rx_errors),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_INVALID,
atomic_long_read(&session->stats.rx_invalid),
L2TP_ATTR_STATS_PAD))
goto nla_put_failure;
nla_nest_end(skb, nest);
genlmsg_end(skb, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(skb, hdr);
return -1;
}
static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
{
struct l2tp_session *session;
struct sk_buff *msg;
int ret;
session = l2tp_nl_session_get(info);
if (!session) {
ret = -ENODEV;
goto err;
}
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg) {
ret = -ENOMEM;
goto err_ref;
}
ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
0, session, L2TP_CMD_SESSION_GET);
if (ret < 0)
goto err_ref_msg;
ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
l2tp_session_dec_refcount(session);
return ret;
err_ref_msg:
nlmsg_free(msg);
err_ref:
l2tp_session_dec_refcount(session);
err:
return ret;
}
static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct l2tp_session *session;
struct l2tp_tunnel *tunnel = NULL;
int ti = cb->args[0];
int si = cb->args[1];
for (;;) {
if (!tunnel) {
tunnel = l2tp_tunnel_get_nth(net, ti);
if (!tunnel)
goto out;
}
session = l2tp_session_get_nth(tunnel, si);
if (!session) {
ti++;
l2tp_tunnel_dec_refcount(tunnel);
tunnel = NULL;
si = 0;
continue;
}
if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
session, L2TP_CMD_SESSION_GET) < 0) {
l2tp_session_dec_refcount(session);
l2tp_tunnel_dec_refcount(tunnel);
break;
}
l2tp_session_dec_refcount(session);
si++;
}
out:
cb->args[0] = ti;
cb->args[1] = si;
return skb->len;
}
static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
[L2TP_ATTR_NONE] = { .type = NLA_UNSPEC, },
[L2TP_ATTR_PW_TYPE] = { .type = NLA_U16, },
[L2TP_ATTR_ENCAP_TYPE] = { .type = NLA_U16, },
[L2TP_ATTR_OFFSET] = { .type = NLA_U16, },
[L2TP_ATTR_DATA_SEQ] = { .type = NLA_U8, },
[L2TP_ATTR_L2SPEC_TYPE] = { .type = NLA_U8, },
[L2TP_ATTR_L2SPEC_LEN] = { .type = NLA_U8, },
[L2TP_ATTR_PROTO_VERSION] = { .type = NLA_U8, },
[L2TP_ATTR_CONN_ID] = { .type = NLA_U32, },
[L2TP_ATTR_PEER_CONN_ID] = { .type = NLA_U32, },
[L2TP_ATTR_SESSION_ID] = { .type = NLA_U32, },
[L2TP_ATTR_PEER_SESSION_ID] = { .type = NLA_U32, },
[L2TP_ATTR_UDP_CSUM] = { .type = NLA_U8, },
[L2TP_ATTR_VLAN_ID] = { .type = NLA_U16, },
[L2TP_ATTR_DEBUG] = { .type = NLA_U32, },
[L2TP_ATTR_RECV_SEQ] = { .type = NLA_U8, },
[L2TP_ATTR_SEND_SEQ] = { .type = NLA_U8, },
[L2TP_ATTR_LNS_MODE] = { .type = NLA_U8, },
[L2TP_ATTR_USING_IPSEC] = { .type = NLA_U8, },
[L2TP_ATTR_RECV_TIMEOUT] = { .type = NLA_MSECS, },
[L2TP_ATTR_FD] = { .type = NLA_U32, },
[L2TP_ATTR_IP_SADDR] = { .type = NLA_U32, },
[L2TP_ATTR_IP_DADDR] = { .type = NLA_U32, },
[L2TP_ATTR_UDP_SPORT] = { .type = NLA_U16, },
[L2TP_ATTR_UDP_DPORT] = { .type = NLA_U16, },
[L2TP_ATTR_MTU] = { .type = NLA_U16, },
[L2TP_ATTR_MRU] = { .type = NLA_U16, },
[L2TP_ATTR_STATS] = { .type = NLA_NESTED, },
[L2TP_ATTR_IP6_SADDR] = {
.type = NLA_BINARY,
.len = sizeof(struct in6_addr),
},
[L2TP_ATTR_IP6_DADDR] = {
.type = NLA_BINARY,
.len = sizeof(struct in6_addr),
},
[L2TP_ATTR_IFNAME] = {
.type = NLA_NUL_STRING,
.len = IFNAMSIZ - 1,
},
[L2TP_ATTR_COOKIE] = {
.type = NLA_BINARY,
.len = 8,
},
[L2TP_ATTR_PEER_COOKIE] = {
.type = NLA_BINARY,
.len = 8,
},
};
static const struct genl_small_ops l2tp_nl_ops[] = {
{
.cmd = L2TP_CMD_NOOP,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_noop,
/* can be retrieved by unprivileged users */
},
{
.cmd = L2TP_CMD_TUNNEL_CREATE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_tunnel_create,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_TUNNEL_DELETE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_tunnel_delete,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_TUNNEL_MODIFY,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_tunnel_modify,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_TUNNEL_GET,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_tunnel_get,
.dumpit = l2tp_nl_cmd_tunnel_dump,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_SESSION_CREATE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_session_create,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_SESSION_DELETE,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_session_delete,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_SESSION_MODIFY,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_session_modify,
.flags = GENL_UNS_ADMIN_PERM,
},
{
.cmd = L2TP_CMD_SESSION_GET,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = l2tp_nl_cmd_session_get,
.dumpit = l2tp_nl_cmd_session_dump,
.flags = GENL_UNS_ADMIN_PERM,
},
};
static struct genl_family l2tp_nl_family __ro_after_init = {
.name = L2TP_GENL_NAME,
.version = L2TP_GENL_VERSION,
.hdrsize = 0,
.maxattr = L2TP_ATTR_MAX,
.policy = l2tp_nl_policy,
.netnsok = true,
.module = THIS_MODULE,
.small_ops = l2tp_nl_ops,
.n_small_ops = ARRAY_SIZE(l2tp_nl_ops),
.mcgrps = l2tp_multicast_group,
.n_mcgrps = ARRAY_SIZE(l2tp_multicast_group),
};
int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
{
int ret;
ret = -EINVAL;
if (pw_type >= __L2TP_PWTYPE_MAX)
goto err;
genl_lock();
ret = -EBUSY;
if (l2tp_nl_cmd_ops[pw_type])
goto out;
l2tp_nl_cmd_ops[pw_type] = ops;
ret = 0;
out:
genl_unlock();
err:
return ret;
}
EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
{
if (pw_type < __L2TP_PWTYPE_MAX) {
genl_lock();
l2tp_nl_cmd_ops[pw_type] = NULL;
genl_unlock();
}
}
EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
static int __init l2tp_nl_init(void)
{
pr_info("L2TP netlink interface\n");
return genl_register_family(&l2tp_nl_family);
}
static void l2tp_nl_cleanup(void)
{
genl_unregister_family(&l2tp_nl_family);
}
module_init(l2tp_nl_init);
module_exit(l2tp_nl_cleanup);
MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
MODULE_DESCRIPTION("L2TP netlink");
MODULE_LICENSE("GPL");
MODULE_VERSION("1.0");
MODULE_ALIAS_GENL_FAMILY("l2tp");
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