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419ce133ab
As reported by Tom, .NET and applications build on top of it rely
on connect(AF_UNSPEC) to async cancel pending I/O operations on TCP
socket.
The blamed commit below caused a regression, as such cancellation
can now fail.
As suggested by Eric, this change addresses the problem explicitly
causing blocking I/O operation to terminate immediately (with an error)
when a concurrent disconnect() is executed.
Instead of tracking the number of threads blocked on a given socket,
track the number of disconnect() issued on such socket. If such counter
changes after a blocking operation releasing and re-acquiring the socket
lock, error out the current operation.
Fixes: 4faeee0cf8
("tcp: deny tcp_disconnect() when threads are waiting")
Reported-by: Tom Deseyn <tdeseyn@redhat.com>
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1886305
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/f3b95e47e3dbed840960548aebaa8d954372db41.1697008693.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1498 lines
41 KiB
C
1498 lines
41 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Support for INET connection oriented protocols.
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*
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* Authors: See the TCP sources
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*/
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#include <linux/module.h>
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#include <linux/jhash.h>
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#include <net/inet_connection_sock.h>
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#include <net/inet_hashtables.h>
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#include <net/inet_timewait_sock.h>
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#include <net/ip.h>
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#include <net/route.h>
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#include <net/tcp_states.h>
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#include <net/xfrm.h>
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#include <net/tcp.h>
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#include <net/sock_reuseport.h>
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#include <net/addrconf.h>
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#if IS_ENABLED(CONFIG_IPV6)
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/* match_sk*_wildcard == true: IPV6_ADDR_ANY equals to any IPv6 addresses
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* if IPv6 only, and any IPv4 addresses
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* if not IPv6 only
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* match_sk*_wildcard == false: addresses must be exactly the same, i.e.
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* IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
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* and 0.0.0.0 equals to 0.0.0.0 only
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*/
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static bool ipv6_rcv_saddr_equal(const struct in6_addr *sk1_rcv_saddr6,
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const struct in6_addr *sk2_rcv_saddr6,
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__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
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bool sk1_ipv6only, bool sk2_ipv6only,
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bool match_sk1_wildcard,
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bool match_sk2_wildcard)
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{
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int addr_type = ipv6_addr_type(sk1_rcv_saddr6);
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int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
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/* if both are mapped, treat as IPv4 */
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if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) {
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if (!sk2_ipv6only) {
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if (sk1_rcv_saddr == sk2_rcv_saddr)
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return true;
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return (match_sk1_wildcard && !sk1_rcv_saddr) ||
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(match_sk2_wildcard && !sk2_rcv_saddr);
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}
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return false;
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}
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if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY)
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return true;
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if (addr_type2 == IPV6_ADDR_ANY && match_sk2_wildcard &&
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!(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
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return true;
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if (addr_type == IPV6_ADDR_ANY && match_sk1_wildcard &&
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!(sk1_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
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return true;
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if (sk2_rcv_saddr6 &&
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ipv6_addr_equal(sk1_rcv_saddr6, sk2_rcv_saddr6))
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return true;
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return false;
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}
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#endif
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/* match_sk*_wildcard == true: 0.0.0.0 equals to any IPv4 addresses
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* match_sk*_wildcard == false: addresses must be exactly the same, i.e.
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* 0.0.0.0 only equals to 0.0.0.0
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*/
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static bool ipv4_rcv_saddr_equal(__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
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bool sk2_ipv6only, bool match_sk1_wildcard,
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bool match_sk2_wildcard)
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{
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if (!sk2_ipv6only) {
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if (sk1_rcv_saddr == sk2_rcv_saddr)
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return true;
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return (match_sk1_wildcard && !sk1_rcv_saddr) ||
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(match_sk2_wildcard && !sk2_rcv_saddr);
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}
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return false;
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}
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bool inet_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2,
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bool match_wildcard)
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{
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#if IS_ENABLED(CONFIG_IPV6)
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if (sk->sk_family == AF_INET6)
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return ipv6_rcv_saddr_equal(&sk->sk_v6_rcv_saddr,
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inet6_rcv_saddr(sk2),
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sk->sk_rcv_saddr,
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sk2->sk_rcv_saddr,
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ipv6_only_sock(sk),
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ipv6_only_sock(sk2),
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match_wildcard,
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match_wildcard);
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#endif
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return ipv4_rcv_saddr_equal(sk->sk_rcv_saddr, sk2->sk_rcv_saddr,
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ipv6_only_sock(sk2), match_wildcard,
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match_wildcard);
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}
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EXPORT_SYMBOL(inet_rcv_saddr_equal);
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bool inet_rcv_saddr_any(const struct sock *sk)
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{
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#if IS_ENABLED(CONFIG_IPV6)
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if (sk->sk_family == AF_INET6)
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return ipv6_addr_any(&sk->sk_v6_rcv_saddr);
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#endif
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return !sk->sk_rcv_saddr;
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}
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void inet_get_local_port_range(const struct net *net, int *low, int *high)
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{
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unsigned int seq;
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do {
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seq = read_seqbegin(&net->ipv4.ip_local_ports.lock);
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*low = net->ipv4.ip_local_ports.range[0];
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*high = net->ipv4.ip_local_ports.range[1];
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} while (read_seqretry(&net->ipv4.ip_local_ports.lock, seq));
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}
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EXPORT_SYMBOL(inet_get_local_port_range);
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void inet_sk_get_local_port_range(const struct sock *sk, int *low, int *high)
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{
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const struct inet_sock *inet = inet_sk(sk);
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const struct net *net = sock_net(sk);
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int lo, hi, sk_lo, sk_hi;
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inet_get_local_port_range(net, &lo, &hi);
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sk_lo = inet->local_port_range.lo;
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sk_hi = inet->local_port_range.hi;
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if (unlikely(lo <= sk_lo && sk_lo <= hi))
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lo = sk_lo;
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if (unlikely(lo <= sk_hi && sk_hi <= hi))
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hi = sk_hi;
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*low = lo;
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*high = hi;
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}
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EXPORT_SYMBOL(inet_sk_get_local_port_range);
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static bool inet_use_bhash2_on_bind(const struct sock *sk)
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{
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#if IS_ENABLED(CONFIG_IPV6)
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if (sk->sk_family == AF_INET6) {
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int addr_type = ipv6_addr_type(&sk->sk_v6_rcv_saddr);
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return addr_type != IPV6_ADDR_ANY &&
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addr_type != IPV6_ADDR_MAPPED;
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}
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#endif
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return sk->sk_rcv_saddr != htonl(INADDR_ANY);
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}
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static bool inet_bind_conflict(const struct sock *sk, struct sock *sk2,
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kuid_t sk_uid, bool relax,
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bool reuseport_cb_ok, bool reuseport_ok)
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{
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int bound_dev_if2;
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if (sk == sk2)
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return false;
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bound_dev_if2 = READ_ONCE(sk2->sk_bound_dev_if);
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if (!sk->sk_bound_dev_if || !bound_dev_if2 ||
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sk->sk_bound_dev_if == bound_dev_if2) {
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if (sk->sk_reuse && sk2->sk_reuse &&
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sk2->sk_state != TCP_LISTEN) {
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if (!relax || (!reuseport_ok && sk->sk_reuseport &&
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sk2->sk_reuseport && reuseport_cb_ok &&
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(sk2->sk_state == TCP_TIME_WAIT ||
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uid_eq(sk_uid, sock_i_uid(sk2)))))
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return true;
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} else if (!reuseport_ok || !sk->sk_reuseport ||
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!sk2->sk_reuseport || !reuseport_cb_ok ||
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(sk2->sk_state != TCP_TIME_WAIT &&
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!uid_eq(sk_uid, sock_i_uid(sk2)))) {
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return true;
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}
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}
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return false;
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}
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static bool __inet_bhash2_conflict(const struct sock *sk, struct sock *sk2,
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kuid_t sk_uid, bool relax,
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bool reuseport_cb_ok, bool reuseport_ok)
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{
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if (sk->sk_family == AF_INET && ipv6_only_sock(sk2))
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return false;
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return inet_bind_conflict(sk, sk2, sk_uid, relax,
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reuseport_cb_ok, reuseport_ok);
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}
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static bool inet_bhash2_conflict(const struct sock *sk,
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const struct inet_bind2_bucket *tb2,
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kuid_t sk_uid,
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bool relax, bool reuseport_cb_ok,
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bool reuseport_ok)
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{
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struct inet_timewait_sock *tw2;
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struct sock *sk2;
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sk_for_each_bound_bhash2(sk2, &tb2->owners) {
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if (__inet_bhash2_conflict(sk, sk2, sk_uid, relax,
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reuseport_cb_ok, reuseport_ok))
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return true;
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}
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twsk_for_each_bound_bhash2(tw2, &tb2->deathrow) {
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sk2 = (struct sock *)tw2;
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if (__inet_bhash2_conflict(sk, sk2, sk_uid, relax,
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reuseport_cb_ok, reuseport_ok))
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return true;
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}
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return false;
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}
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/* This should be called only when the tb and tb2 hashbuckets' locks are held */
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static int inet_csk_bind_conflict(const struct sock *sk,
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const struct inet_bind_bucket *tb,
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const struct inet_bind2_bucket *tb2, /* may be null */
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bool relax, bool reuseport_ok)
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{
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bool reuseport_cb_ok;
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struct sock_reuseport *reuseport_cb;
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kuid_t uid = sock_i_uid((struct sock *)sk);
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rcu_read_lock();
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reuseport_cb = rcu_dereference(sk->sk_reuseport_cb);
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/* paired with WRITE_ONCE() in __reuseport_(add|detach)_closed_sock */
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reuseport_cb_ok = !reuseport_cb || READ_ONCE(reuseport_cb->num_closed_socks);
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rcu_read_unlock();
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/*
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* Unlike other sk lookup places we do not check
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* for sk_net here, since _all_ the socks listed
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* in tb->owners and tb2->owners list belong
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* to the same net - the one this bucket belongs to.
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*/
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if (!inet_use_bhash2_on_bind(sk)) {
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struct sock *sk2;
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sk_for_each_bound(sk2, &tb->owners)
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if (inet_bind_conflict(sk, sk2, uid, relax,
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reuseport_cb_ok, reuseport_ok) &&
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inet_rcv_saddr_equal(sk, sk2, true))
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return true;
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return false;
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}
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/* Conflicts with an existing IPV6_ADDR_ANY (if ipv6) or INADDR_ANY (if
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* ipv4) should have been checked already. We need to do these two
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* checks separately because their spinlocks have to be acquired/released
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* independently of each other, to prevent possible deadlocks
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*/
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return tb2 && inet_bhash2_conflict(sk, tb2, uid, relax, reuseport_cb_ok,
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reuseport_ok);
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}
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/* Determine if there is a bind conflict with an existing IPV6_ADDR_ANY (if ipv6) or
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* INADDR_ANY (if ipv4) socket.
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*
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* Caller must hold bhash hashbucket lock with local bh disabled, to protect
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* against concurrent binds on the port for addr any
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*/
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static bool inet_bhash2_addr_any_conflict(const struct sock *sk, int port, int l3mdev,
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bool relax, bool reuseport_ok)
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{
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kuid_t uid = sock_i_uid((struct sock *)sk);
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const struct net *net = sock_net(sk);
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struct sock_reuseport *reuseport_cb;
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struct inet_bind_hashbucket *head2;
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struct inet_bind2_bucket *tb2;
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bool reuseport_cb_ok;
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rcu_read_lock();
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reuseport_cb = rcu_dereference(sk->sk_reuseport_cb);
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/* paired with WRITE_ONCE() in __reuseport_(add|detach)_closed_sock */
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reuseport_cb_ok = !reuseport_cb || READ_ONCE(reuseport_cb->num_closed_socks);
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rcu_read_unlock();
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head2 = inet_bhash2_addr_any_hashbucket(sk, net, port);
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spin_lock(&head2->lock);
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inet_bind_bucket_for_each(tb2, &head2->chain)
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if (inet_bind2_bucket_match_addr_any(tb2, net, port, l3mdev, sk))
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break;
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if (tb2 && inet_bhash2_conflict(sk, tb2, uid, relax, reuseport_cb_ok,
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reuseport_ok)) {
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spin_unlock(&head2->lock);
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return true;
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}
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spin_unlock(&head2->lock);
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return false;
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}
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/*
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* Find an open port number for the socket. Returns with the
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* inet_bind_hashbucket locks held if successful.
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*/
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static struct inet_bind_hashbucket *
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inet_csk_find_open_port(const struct sock *sk, struct inet_bind_bucket **tb_ret,
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struct inet_bind2_bucket **tb2_ret,
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struct inet_bind_hashbucket **head2_ret, int *port_ret)
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{
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struct inet_hashinfo *hinfo = tcp_or_dccp_get_hashinfo(sk);
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int i, low, high, attempt_half, port, l3mdev;
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struct inet_bind_hashbucket *head, *head2;
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struct net *net = sock_net(sk);
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struct inet_bind2_bucket *tb2;
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struct inet_bind_bucket *tb;
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u32 remaining, offset;
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bool relax = false;
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l3mdev = inet_sk_bound_l3mdev(sk);
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ports_exhausted:
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attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0;
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other_half_scan:
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inet_sk_get_local_port_range(sk, &low, &high);
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high++; /* [32768, 60999] -> [32768, 61000[ */
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if (high - low < 4)
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attempt_half = 0;
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if (attempt_half) {
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int half = low + (((high - low) >> 2) << 1);
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|
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if (attempt_half == 1)
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high = half;
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else
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low = half;
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}
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remaining = high - low;
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if (likely(remaining > 1))
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remaining &= ~1U;
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offset = get_random_u32_below(remaining);
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/* __inet_hash_connect() favors ports having @low parity
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* We do the opposite to not pollute connect() users.
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*/
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offset |= 1U;
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other_parity_scan:
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port = low + offset;
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for (i = 0; i < remaining; i += 2, port += 2) {
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if (unlikely(port >= high))
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port -= remaining;
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if (inet_is_local_reserved_port(net, port))
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continue;
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head = &hinfo->bhash[inet_bhashfn(net, port,
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hinfo->bhash_size)];
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spin_lock_bh(&head->lock);
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if (inet_use_bhash2_on_bind(sk)) {
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if (inet_bhash2_addr_any_conflict(sk, port, l3mdev, relax, false))
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goto next_port;
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}
|
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head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
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spin_lock(&head2->lock);
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tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, sk);
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inet_bind_bucket_for_each(tb, &head->chain)
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if (inet_bind_bucket_match(tb, net, port, l3mdev)) {
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if (!inet_csk_bind_conflict(sk, tb, tb2,
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relax, false))
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goto success;
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spin_unlock(&head2->lock);
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goto next_port;
|
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}
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tb = NULL;
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goto success;
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next_port:
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spin_unlock_bh(&head->lock);
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cond_resched();
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}
|
|
|
|
offset--;
|
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if (!(offset & 1))
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goto other_parity_scan;
|
|
|
|
if (attempt_half == 1) {
|
|
/* OK we now try the upper half of the range */
|
|
attempt_half = 2;
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goto other_half_scan;
|
|
}
|
|
|
|
if (READ_ONCE(net->ipv4.sysctl_ip_autobind_reuse) && !relax) {
|
|
/* We still have a chance to connect to different destinations */
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|
relax = true;
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|
goto ports_exhausted;
|
|
}
|
|
return NULL;
|
|
success:
|
|
*port_ret = port;
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|
*tb_ret = tb;
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*tb2_ret = tb2;
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*head2_ret = head2;
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|
return head;
|
|
}
|
|
|
|
static inline int sk_reuseport_match(struct inet_bind_bucket *tb,
|
|
struct sock *sk)
|
|
{
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|
kuid_t uid = sock_i_uid(sk);
|
|
|
|
if (tb->fastreuseport <= 0)
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return 0;
|
|
if (!sk->sk_reuseport)
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|
return 0;
|
|
if (rcu_access_pointer(sk->sk_reuseport_cb))
|
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return 0;
|
|
if (!uid_eq(tb->fastuid, uid))
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return 0;
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|
/* We only need to check the rcv_saddr if this tb was once marked
|
|
* without fastreuseport and then was reset, as we can only know that
|
|
* the fast_*rcv_saddr doesn't have any conflicts with the socks on the
|
|
* owners list.
|
|
*/
|
|
if (tb->fastreuseport == FASTREUSEPORT_ANY)
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|
return 1;
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
if (tb->fast_sk_family == AF_INET6)
|
|
return ipv6_rcv_saddr_equal(&tb->fast_v6_rcv_saddr,
|
|
inet6_rcv_saddr(sk),
|
|
tb->fast_rcv_saddr,
|
|
sk->sk_rcv_saddr,
|
|
tb->fast_ipv6_only,
|
|
ipv6_only_sock(sk), true, false);
|
|
#endif
|
|
return ipv4_rcv_saddr_equal(tb->fast_rcv_saddr, sk->sk_rcv_saddr,
|
|
ipv6_only_sock(sk), true, false);
|
|
}
|
|
|
|
void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
|
|
struct sock *sk)
|
|
{
|
|
kuid_t uid = sock_i_uid(sk);
|
|
bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
|
|
|
|
if (hlist_empty(&tb->owners)) {
|
|
tb->fastreuse = reuse;
|
|
if (sk->sk_reuseport) {
|
|
tb->fastreuseport = FASTREUSEPORT_ANY;
|
|
tb->fastuid = uid;
|
|
tb->fast_rcv_saddr = sk->sk_rcv_saddr;
|
|
tb->fast_ipv6_only = ipv6_only_sock(sk);
|
|
tb->fast_sk_family = sk->sk_family;
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
|
|
#endif
|
|
} else {
|
|
tb->fastreuseport = 0;
|
|
}
|
|
} else {
|
|
if (!reuse)
|
|
tb->fastreuse = 0;
|
|
if (sk->sk_reuseport) {
|
|
/* We didn't match or we don't have fastreuseport set on
|
|
* the tb, but we have sk_reuseport set on this socket
|
|
* and we know that there are no bind conflicts with
|
|
* this socket in this tb, so reset our tb's reuseport
|
|
* settings so that any subsequent sockets that match
|
|
* our current socket will be put on the fast path.
|
|
*
|
|
* If we reset we need to set FASTREUSEPORT_STRICT so we
|
|
* do extra checking for all subsequent sk_reuseport
|
|
* socks.
|
|
*/
|
|
if (!sk_reuseport_match(tb, sk)) {
|
|
tb->fastreuseport = FASTREUSEPORT_STRICT;
|
|
tb->fastuid = uid;
|
|
tb->fast_rcv_saddr = sk->sk_rcv_saddr;
|
|
tb->fast_ipv6_only = ipv6_only_sock(sk);
|
|
tb->fast_sk_family = sk->sk_family;
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
|
|
#endif
|
|
}
|
|
} else {
|
|
tb->fastreuseport = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Obtain a reference to a local port for the given sock,
|
|
* if snum is zero it means select any available local port.
|
|
* We try to allocate an odd port (and leave even ports for connect())
|
|
*/
|
|
int inet_csk_get_port(struct sock *sk, unsigned short snum)
|
|
{
|
|
struct inet_hashinfo *hinfo = tcp_or_dccp_get_hashinfo(sk);
|
|
bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
|
|
bool found_port = false, check_bind_conflict = true;
|
|
bool bhash_created = false, bhash2_created = false;
|
|
int ret = -EADDRINUSE, port = snum, l3mdev;
|
|
struct inet_bind_hashbucket *head, *head2;
|
|
struct inet_bind2_bucket *tb2 = NULL;
|
|
struct inet_bind_bucket *tb = NULL;
|
|
bool head2_lock_acquired = false;
|
|
struct net *net = sock_net(sk);
|
|
|
|
l3mdev = inet_sk_bound_l3mdev(sk);
|
|
|
|
if (!port) {
|
|
head = inet_csk_find_open_port(sk, &tb, &tb2, &head2, &port);
|
|
if (!head)
|
|
return ret;
|
|
|
|
head2_lock_acquired = true;
|
|
|
|
if (tb && tb2)
|
|
goto success;
|
|
found_port = true;
|
|
} else {
|
|
head = &hinfo->bhash[inet_bhashfn(net, port,
|
|
hinfo->bhash_size)];
|
|
spin_lock_bh(&head->lock);
|
|
inet_bind_bucket_for_each(tb, &head->chain)
|
|
if (inet_bind_bucket_match(tb, net, port, l3mdev))
|
|
break;
|
|
}
|
|
|
|
if (!tb) {
|
|
tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, net,
|
|
head, port, l3mdev);
|
|
if (!tb)
|
|
goto fail_unlock;
|
|
bhash_created = true;
|
|
}
|
|
|
|
if (!found_port) {
|
|
if (!hlist_empty(&tb->owners)) {
|
|
if (sk->sk_reuse == SK_FORCE_REUSE ||
|
|
(tb->fastreuse > 0 && reuse) ||
|
|
sk_reuseport_match(tb, sk))
|
|
check_bind_conflict = false;
|
|
}
|
|
|
|
if (check_bind_conflict && inet_use_bhash2_on_bind(sk)) {
|
|
if (inet_bhash2_addr_any_conflict(sk, port, l3mdev, true, true))
|
|
goto fail_unlock;
|
|
}
|
|
|
|
head2 = inet_bhashfn_portaddr(hinfo, sk, net, port);
|
|
spin_lock(&head2->lock);
|
|
head2_lock_acquired = true;
|
|
tb2 = inet_bind2_bucket_find(head2, net, port, l3mdev, sk);
|
|
}
|
|
|
|
if (!tb2) {
|
|
tb2 = inet_bind2_bucket_create(hinfo->bind2_bucket_cachep,
|
|
net, head2, port, l3mdev, sk);
|
|
if (!tb2)
|
|
goto fail_unlock;
|
|
bhash2_created = true;
|
|
}
|
|
|
|
if (!found_port && check_bind_conflict) {
|
|
if (inet_csk_bind_conflict(sk, tb, tb2, true, true))
|
|
goto fail_unlock;
|
|
}
|
|
|
|
success:
|
|
inet_csk_update_fastreuse(tb, sk);
|
|
|
|
if (!inet_csk(sk)->icsk_bind_hash)
|
|
inet_bind_hash(sk, tb, tb2, port);
|
|
WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
|
|
WARN_ON(inet_csk(sk)->icsk_bind2_hash != tb2);
|
|
ret = 0;
|
|
|
|
fail_unlock:
|
|
if (ret) {
|
|
if (bhash_created)
|
|
inet_bind_bucket_destroy(hinfo->bind_bucket_cachep, tb);
|
|
if (bhash2_created)
|
|
inet_bind2_bucket_destroy(hinfo->bind2_bucket_cachep,
|
|
tb2);
|
|
}
|
|
if (head2_lock_acquired)
|
|
spin_unlock(&head2->lock);
|
|
spin_unlock_bh(&head->lock);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_get_port);
|
|
|
|
/*
|
|
* Wait for an incoming connection, avoid race conditions. This must be called
|
|
* with the socket locked.
|
|
*/
|
|
static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
DEFINE_WAIT(wait);
|
|
int err;
|
|
|
|
/*
|
|
* True wake-one mechanism for incoming connections: only
|
|
* one process gets woken up, not the 'whole herd'.
|
|
* Since we do not 'race & poll' for established sockets
|
|
* anymore, the common case will execute the loop only once.
|
|
*
|
|
* Subtle issue: "add_wait_queue_exclusive()" will be added
|
|
* after any current non-exclusive waiters, and we know that
|
|
* it will always _stay_ after any new non-exclusive waiters
|
|
* because all non-exclusive waiters are added at the
|
|
* beginning of the wait-queue. As such, it's ok to "drop"
|
|
* our exclusiveness temporarily when we get woken up without
|
|
* having to remove and re-insert us on the wait queue.
|
|
*/
|
|
for (;;) {
|
|
prepare_to_wait_exclusive(sk_sleep(sk), &wait,
|
|
TASK_INTERRUPTIBLE);
|
|
release_sock(sk);
|
|
if (reqsk_queue_empty(&icsk->icsk_accept_queue))
|
|
timeo = schedule_timeout(timeo);
|
|
sched_annotate_sleep();
|
|
lock_sock(sk);
|
|
err = 0;
|
|
if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
|
|
break;
|
|
err = -EINVAL;
|
|
if (sk->sk_state != TCP_LISTEN)
|
|
break;
|
|
err = sock_intr_errno(timeo);
|
|
if (signal_pending(current))
|
|
break;
|
|
err = -EAGAIN;
|
|
if (!timeo)
|
|
break;
|
|
}
|
|
finish_wait(sk_sleep(sk), &wait);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* This will accept the next outstanding connection.
|
|
*/
|
|
struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct request_sock_queue *queue = &icsk->icsk_accept_queue;
|
|
struct request_sock *req;
|
|
struct sock *newsk;
|
|
int error;
|
|
|
|
lock_sock(sk);
|
|
|
|
/* We need to make sure that this socket is listening,
|
|
* and that it has something pending.
|
|
*/
|
|
error = -EINVAL;
|
|
if (sk->sk_state != TCP_LISTEN)
|
|
goto out_err;
|
|
|
|
/* Find already established connection */
|
|
if (reqsk_queue_empty(queue)) {
|
|
long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
|
|
|
|
/* If this is a non blocking socket don't sleep */
|
|
error = -EAGAIN;
|
|
if (!timeo)
|
|
goto out_err;
|
|
|
|
error = inet_csk_wait_for_connect(sk, timeo);
|
|
if (error)
|
|
goto out_err;
|
|
}
|
|
req = reqsk_queue_remove(queue, sk);
|
|
newsk = req->sk;
|
|
|
|
if (sk->sk_protocol == IPPROTO_TCP &&
|
|
tcp_rsk(req)->tfo_listener) {
|
|
spin_lock_bh(&queue->fastopenq.lock);
|
|
if (tcp_rsk(req)->tfo_listener) {
|
|
/* We are still waiting for the final ACK from 3WHS
|
|
* so can't free req now. Instead, we set req->sk to
|
|
* NULL to signify that the child socket is taken
|
|
* so reqsk_fastopen_remove() will free the req
|
|
* when 3WHS finishes (or is aborted).
|
|
*/
|
|
req->sk = NULL;
|
|
req = NULL;
|
|
}
|
|
spin_unlock_bh(&queue->fastopenq.lock);
|
|
}
|
|
|
|
out:
|
|
release_sock(sk);
|
|
if (newsk && mem_cgroup_sockets_enabled) {
|
|
int amt = 0;
|
|
|
|
/* atomically get the memory usage, set and charge the
|
|
* newsk->sk_memcg.
|
|
*/
|
|
lock_sock(newsk);
|
|
|
|
mem_cgroup_sk_alloc(newsk);
|
|
if (newsk->sk_memcg) {
|
|
/* The socket has not been accepted yet, no need
|
|
* to look at newsk->sk_wmem_queued.
|
|
*/
|
|
amt = sk_mem_pages(newsk->sk_forward_alloc +
|
|
atomic_read(&newsk->sk_rmem_alloc));
|
|
}
|
|
|
|
if (amt)
|
|
mem_cgroup_charge_skmem(newsk->sk_memcg, amt,
|
|
GFP_KERNEL | __GFP_NOFAIL);
|
|
|
|
release_sock(newsk);
|
|
}
|
|
if (req)
|
|
reqsk_put(req);
|
|
return newsk;
|
|
out_err:
|
|
newsk = NULL;
|
|
req = NULL;
|
|
*err = error;
|
|
goto out;
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_accept);
|
|
|
|
/*
|
|
* Using different timers for retransmit, delayed acks and probes
|
|
* We may wish use just one timer maintaining a list of expire jiffies
|
|
* to optimize.
|
|
*/
|
|
void inet_csk_init_xmit_timers(struct sock *sk,
|
|
void (*retransmit_handler)(struct timer_list *t),
|
|
void (*delack_handler)(struct timer_list *t),
|
|
void (*keepalive_handler)(struct timer_list *t))
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
timer_setup(&icsk->icsk_retransmit_timer, retransmit_handler, 0);
|
|
timer_setup(&icsk->icsk_delack_timer, delack_handler, 0);
|
|
timer_setup(&sk->sk_timer, keepalive_handler, 0);
|
|
icsk->icsk_pending = icsk->icsk_ack.pending = 0;
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_init_xmit_timers);
|
|
|
|
void inet_csk_clear_xmit_timers(struct sock *sk)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
icsk->icsk_pending = icsk->icsk_ack.pending = 0;
|
|
|
|
sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
|
|
sk_stop_timer(sk, &icsk->icsk_delack_timer);
|
|
sk_stop_timer(sk, &sk->sk_timer);
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
|
|
|
|
void inet_csk_delete_keepalive_timer(struct sock *sk)
|
|
{
|
|
sk_stop_timer(sk, &sk->sk_timer);
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
|
|
|
|
void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
|
|
{
|
|
sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
|
|
|
|
struct dst_entry *inet_csk_route_req(const struct sock *sk,
|
|
struct flowi4 *fl4,
|
|
const struct request_sock *req)
|
|
{
|
|
const struct inet_request_sock *ireq = inet_rsk(req);
|
|
struct net *net = read_pnet(&ireq->ireq_net);
|
|
struct ip_options_rcu *opt;
|
|
struct rtable *rt;
|
|
|
|
rcu_read_lock();
|
|
opt = rcu_dereference(ireq->ireq_opt);
|
|
|
|
flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
|
|
ip_sock_rt_tos(sk), ip_sock_rt_scope(sk),
|
|
sk->sk_protocol, inet_sk_flowi_flags(sk),
|
|
(opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
|
|
ireq->ir_loc_addr, ireq->ir_rmt_port,
|
|
htons(ireq->ir_num), sk->sk_uid);
|
|
security_req_classify_flow(req, flowi4_to_flowi_common(fl4));
|
|
rt = ip_route_output_flow(net, fl4, sk);
|
|
if (IS_ERR(rt))
|
|
goto no_route;
|
|
if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
|
|
goto route_err;
|
|
rcu_read_unlock();
|
|
return &rt->dst;
|
|
|
|
route_err:
|
|
ip_rt_put(rt);
|
|
no_route:
|
|
rcu_read_unlock();
|
|
__IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_route_req);
|
|
|
|
struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
|
|
struct sock *newsk,
|
|
const struct request_sock *req)
|
|
{
|
|
const struct inet_request_sock *ireq = inet_rsk(req);
|
|
struct net *net = read_pnet(&ireq->ireq_net);
|
|
struct inet_sock *newinet = inet_sk(newsk);
|
|
struct ip_options_rcu *opt;
|
|
struct flowi4 *fl4;
|
|
struct rtable *rt;
|
|
|
|
opt = rcu_dereference(ireq->ireq_opt);
|
|
fl4 = &newinet->cork.fl.u.ip4;
|
|
|
|
flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
|
|
ip_sock_rt_tos(sk), ip_sock_rt_scope(sk),
|
|
sk->sk_protocol, inet_sk_flowi_flags(sk),
|
|
(opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
|
|
ireq->ir_loc_addr, ireq->ir_rmt_port,
|
|
htons(ireq->ir_num), sk->sk_uid);
|
|
security_req_classify_flow(req, flowi4_to_flowi_common(fl4));
|
|
rt = ip_route_output_flow(net, fl4, sk);
|
|
if (IS_ERR(rt))
|
|
goto no_route;
|
|
if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
|
|
goto route_err;
|
|
return &rt->dst;
|
|
|
|
route_err:
|
|
ip_rt_put(rt);
|
|
no_route:
|
|
__IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
|
|
|
|
/* Decide when to expire the request and when to resend SYN-ACK */
|
|
static void syn_ack_recalc(struct request_sock *req,
|
|
const int max_syn_ack_retries,
|
|
const u8 rskq_defer_accept,
|
|
int *expire, int *resend)
|
|
{
|
|
if (!rskq_defer_accept) {
|
|
*expire = req->num_timeout >= max_syn_ack_retries;
|
|
*resend = 1;
|
|
return;
|
|
}
|
|
*expire = req->num_timeout >= max_syn_ack_retries &&
|
|
(!inet_rsk(req)->acked || req->num_timeout >= rskq_defer_accept);
|
|
/* Do not resend while waiting for data after ACK,
|
|
* start to resend on end of deferring period to give
|
|
* last chance for data or ACK to create established socket.
|
|
*/
|
|
*resend = !inet_rsk(req)->acked ||
|
|
req->num_timeout >= rskq_defer_accept - 1;
|
|
}
|
|
|
|
int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req)
|
|
{
|
|
int err = req->rsk_ops->rtx_syn_ack(parent, req);
|
|
|
|
if (!err)
|
|
req->num_retrans++;
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(inet_rtx_syn_ack);
|
|
|
|
static struct request_sock *inet_reqsk_clone(struct request_sock *req,
|
|
struct sock *sk)
|
|
{
|
|
struct sock *req_sk, *nreq_sk;
|
|
struct request_sock *nreq;
|
|
|
|
nreq = kmem_cache_alloc(req->rsk_ops->slab, GFP_ATOMIC | __GFP_NOWARN);
|
|
if (!nreq) {
|
|
__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMIGRATEREQFAILURE);
|
|
|
|
/* paired with refcount_inc_not_zero() in reuseport_migrate_sock() */
|
|
sock_put(sk);
|
|
return NULL;
|
|
}
|
|
|
|
req_sk = req_to_sk(req);
|
|
nreq_sk = req_to_sk(nreq);
|
|
|
|
memcpy(nreq_sk, req_sk,
|
|
offsetof(struct sock, sk_dontcopy_begin));
|
|
memcpy(&nreq_sk->sk_dontcopy_end, &req_sk->sk_dontcopy_end,
|
|
req->rsk_ops->obj_size - offsetof(struct sock, sk_dontcopy_end));
|
|
|
|
sk_node_init(&nreq_sk->sk_node);
|
|
nreq_sk->sk_tx_queue_mapping = req_sk->sk_tx_queue_mapping;
|
|
#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
|
|
nreq_sk->sk_rx_queue_mapping = req_sk->sk_rx_queue_mapping;
|
|
#endif
|
|
nreq_sk->sk_incoming_cpu = req_sk->sk_incoming_cpu;
|
|
|
|
nreq->rsk_listener = sk;
|
|
|
|
/* We need not acquire fastopenq->lock
|
|
* because the child socket is locked in inet_csk_listen_stop().
|
|
*/
|
|
if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(nreq)->tfo_listener)
|
|
rcu_assign_pointer(tcp_sk(nreq->sk)->fastopen_rsk, nreq);
|
|
|
|
return nreq;
|
|
}
|
|
|
|
static void reqsk_queue_migrated(struct request_sock_queue *queue,
|
|
const struct request_sock *req)
|
|
{
|
|
if (req->num_timeout == 0)
|
|
atomic_inc(&queue->young);
|
|
atomic_inc(&queue->qlen);
|
|
}
|
|
|
|
static void reqsk_migrate_reset(struct request_sock *req)
|
|
{
|
|
req->saved_syn = NULL;
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
inet_rsk(req)->ipv6_opt = NULL;
|
|
inet_rsk(req)->pktopts = NULL;
|
|
#else
|
|
inet_rsk(req)->ireq_opt = NULL;
|
|
#endif
|
|
}
|
|
|
|
/* return true if req was found in the ehash table */
|
|
static bool reqsk_queue_unlink(struct request_sock *req)
|
|
{
|
|
struct sock *sk = req_to_sk(req);
|
|
bool found = false;
|
|
|
|
if (sk_hashed(sk)) {
|
|
struct inet_hashinfo *hashinfo = tcp_or_dccp_get_hashinfo(sk);
|
|
spinlock_t *lock = inet_ehash_lockp(hashinfo, req->rsk_hash);
|
|
|
|
spin_lock(lock);
|
|
found = __sk_nulls_del_node_init_rcu(sk);
|
|
spin_unlock(lock);
|
|
}
|
|
if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer))
|
|
reqsk_put(req);
|
|
return found;
|
|
}
|
|
|
|
bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req)
|
|
{
|
|
bool unlinked = reqsk_queue_unlink(req);
|
|
|
|
if (unlinked) {
|
|
reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
|
|
reqsk_put(req);
|
|
}
|
|
return unlinked;
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_reqsk_queue_drop);
|
|
|
|
void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req)
|
|
{
|
|
inet_csk_reqsk_queue_drop(sk, req);
|
|
reqsk_put(req);
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put);
|
|
|
|
static void reqsk_timer_handler(struct timer_list *t)
|
|
{
|
|
struct request_sock *req = from_timer(req, t, rsk_timer);
|
|
struct request_sock *nreq = NULL, *oreq = req;
|
|
struct sock *sk_listener = req->rsk_listener;
|
|
struct inet_connection_sock *icsk;
|
|
struct request_sock_queue *queue;
|
|
struct net *net;
|
|
int max_syn_ack_retries, qlen, expire = 0, resend = 0;
|
|
|
|
if (inet_sk_state_load(sk_listener) != TCP_LISTEN) {
|
|
struct sock *nsk;
|
|
|
|
nsk = reuseport_migrate_sock(sk_listener, req_to_sk(req), NULL);
|
|
if (!nsk)
|
|
goto drop;
|
|
|
|
nreq = inet_reqsk_clone(req, nsk);
|
|
if (!nreq)
|
|
goto drop;
|
|
|
|
/* The new timer for the cloned req can decrease the 2
|
|
* by calling inet_csk_reqsk_queue_drop_and_put(), so
|
|
* hold another count to prevent use-after-free and
|
|
* call reqsk_put() just before return.
|
|
*/
|
|
refcount_set(&nreq->rsk_refcnt, 2 + 1);
|
|
timer_setup(&nreq->rsk_timer, reqsk_timer_handler, TIMER_PINNED);
|
|
reqsk_queue_migrated(&inet_csk(nsk)->icsk_accept_queue, req);
|
|
|
|
req = nreq;
|
|
sk_listener = nsk;
|
|
}
|
|
|
|
icsk = inet_csk(sk_listener);
|
|
net = sock_net(sk_listener);
|
|
max_syn_ack_retries = READ_ONCE(icsk->icsk_syn_retries) ? :
|
|
READ_ONCE(net->ipv4.sysctl_tcp_synack_retries);
|
|
/* Normally all the openreqs are young and become mature
|
|
* (i.e. converted to established socket) for first timeout.
|
|
* If synack was not acknowledged for 1 second, it means
|
|
* one of the following things: synack was lost, ack was lost,
|
|
* rtt is high or nobody planned to ack (i.e. synflood).
|
|
* When server is a bit loaded, queue is populated with old
|
|
* open requests, reducing effective size of queue.
|
|
* When server is well loaded, queue size reduces to zero
|
|
* after several minutes of work. It is not synflood,
|
|
* it is normal operation. The solution is pruning
|
|
* too old entries overriding normal timeout, when
|
|
* situation becomes dangerous.
|
|
*
|
|
* Essentially, we reserve half of room for young
|
|
* embrions; and abort old ones without pity, if old
|
|
* ones are about to clog our table.
|
|
*/
|
|
queue = &icsk->icsk_accept_queue;
|
|
qlen = reqsk_queue_len(queue);
|
|
if ((qlen << 1) > max(8U, READ_ONCE(sk_listener->sk_max_ack_backlog))) {
|
|
int young = reqsk_queue_len_young(queue) << 1;
|
|
|
|
while (max_syn_ack_retries > 2) {
|
|
if (qlen < young)
|
|
break;
|
|
max_syn_ack_retries--;
|
|
young <<= 1;
|
|
}
|
|
}
|
|
syn_ack_recalc(req, max_syn_ack_retries, READ_ONCE(queue->rskq_defer_accept),
|
|
&expire, &resend);
|
|
req->rsk_ops->syn_ack_timeout(req);
|
|
if (!expire &&
|
|
(!resend ||
|
|
!inet_rtx_syn_ack(sk_listener, req) ||
|
|
inet_rsk(req)->acked)) {
|
|
if (req->num_timeout++ == 0)
|
|
atomic_dec(&queue->young);
|
|
mod_timer(&req->rsk_timer, jiffies + reqsk_timeout(req, TCP_RTO_MAX));
|
|
|
|
if (!nreq)
|
|
return;
|
|
|
|
if (!inet_ehash_insert(req_to_sk(nreq), req_to_sk(oreq), NULL)) {
|
|
/* delete timer */
|
|
inet_csk_reqsk_queue_drop(sk_listener, nreq);
|
|
goto no_ownership;
|
|
}
|
|
|
|
__NET_INC_STATS(net, LINUX_MIB_TCPMIGRATEREQSUCCESS);
|
|
reqsk_migrate_reset(oreq);
|
|
reqsk_queue_removed(&inet_csk(oreq->rsk_listener)->icsk_accept_queue, oreq);
|
|
reqsk_put(oreq);
|
|
|
|
reqsk_put(nreq);
|
|
return;
|
|
}
|
|
|
|
/* Even if we can clone the req, we may need not retransmit any more
|
|
* SYN+ACKs (nreq->num_timeout > max_syn_ack_retries, etc), or another
|
|
* CPU may win the "own_req" race so that inet_ehash_insert() fails.
|
|
*/
|
|
if (nreq) {
|
|
__NET_INC_STATS(net, LINUX_MIB_TCPMIGRATEREQFAILURE);
|
|
no_ownership:
|
|
reqsk_migrate_reset(nreq);
|
|
reqsk_queue_removed(queue, nreq);
|
|
__reqsk_free(nreq);
|
|
}
|
|
|
|
drop:
|
|
inet_csk_reqsk_queue_drop_and_put(oreq->rsk_listener, oreq);
|
|
}
|
|
|
|
static void reqsk_queue_hash_req(struct request_sock *req,
|
|
unsigned long timeout)
|
|
{
|
|
timer_setup(&req->rsk_timer, reqsk_timer_handler, TIMER_PINNED);
|
|
mod_timer(&req->rsk_timer, jiffies + timeout);
|
|
|
|
inet_ehash_insert(req_to_sk(req), NULL, NULL);
|
|
/* before letting lookups find us, make sure all req fields
|
|
* are committed to memory and refcnt initialized.
|
|
*/
|
|
smp_wmb();
|
|
refcount_set(&req->rsk_refcnt, 2 + 1);
|
|
}
|
|
|
|
void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
|
|
unsigned long timeout)
|
|
{
|
|
reqsk_queue_hash_req(req, timeout);
|
|
inet_csk_reqsk_queue_added(sk);
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
|
|
|
|
static void inet_clone_ulp(const struct request_sock *req, struct sock *newsk,
|
|
const gfp_t priority)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(newsk);
|
|
|
|
if (!icsk->icsk_ulp_ops)
|
|
return;
|
|
|
|
icsk->icsk_ulp_ops->clone(req, newsk, priority);
|
|
}
|
|
|
|
/**
|
|
* inet_csk_clone_lock - clone an inet socket, and lock its clone
|
|
* @sk: the socket to clone
|
|
* @req: request_sock
|
|
* @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
|
|
*
|
|
* Caller must unlock socket even in error path (bh_unlock_sock(newsk))
|
|
*/
|
|
struct sock *inet_csk_clone_lock(const struct sock *sk,
|
|
const struct request_sock *req,
|
|
const gfp_t priority)
|
|
{
|
|
struct sock *newsk = sk_clone_lock(sk, priority);
|
|
|
|
if (newsk) {
|
|
struct inet_connection_sock *newicsk = inet_csk(newsk);
|
|
|
|
inet_sk_set_state(newsk, TCP_SYN_RECV);
|
|
newicsk->icsk_bind_hash = NULL;
|
|
newicsk->icsk_bind2_hash = NULL;
|
|
|
|
inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
|
|
inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;
|
|
inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
|
|
|
|
/* listeners have SOCK_RCU_FREE, not the children */
|
|
sock_reset_flag(newsk, SOCK_RCU_FREE);
|
|
|
|
inet_sk(newsk)->mc_list = NULL;
|
|
|
|
newsk->sk_mark = inet_rsk(req)->ir_mark;
|
|
atomic64_set(&newsk->sk_cookie,
|
|
atomic64_read(&inet_rsk(req)->ir_cookie));
|
|
|
|
newicsk->icsk_retransmits = 0;
|
|
newicsk->icsk_backoff = 0;
|
|
newicsk->icsk_probes_out = 0;
|
|
newicsk->icsk_probes_tstamp = 0;
|
|
|
|
/* Deinitialize accept_queue to trap illegal accesses. */
|
|
memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
|
|
|
|
inet_clone_ulp(req, newsk, priority);
|
|
|
|
security_inet_csk_clone(newsk, req);
|
|
}
|
|
return newsk;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_clone_lock);
|
|
|
|
/*
|
|
* At this point, there should be no process reference to this
|
|
* socket, and thus no user references at all. Therefore we
|
|
* can assume the socket waitqueue is inactive and nobody will
|
|
* try to jump onto it.
|
|
*/
|
|
void inet_csk_destroy_sock(struct sock *sk)
|
|
{
|
|
WARN_ON(sk->sk_state != TCP_CLOSE);
|
|
WARN_ON(!sock_flag(sk, SOCK_DEAD));
|
|
|
|
/* It cannot be in hash table! */
|
|
WARN_ON(!sk_unhashed(sk));
|
|
|
|
/* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
|
|
WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
|
|
|
|
sk->sk_prot->destroy(sk);
|
|
|
|
sk_stream_kill_queues(sk);
|
|
|
|
xfrm_sk_free_policy(sk);
|
|
|
|
this_cpu_dec(*sk->sk_prot->orphan_count);
|
|
|
|
sock_put(sk);
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_destroy_sock);
|
|
|
|
/* This function allows to force a closure of a socket after the call to
|
|
* tcp/dccp_create_openreq_child().
|
|
*/
|
|
void inet_csk_prepare_forced_close(struct sock *sk)
|
|
__releases(&sk->sk_lock.slock)
|
|
{
|
|
/* sk_clone_lock locked the socket and set refcnt to 2 */
|
|
bh_unlock_sock(sk);
|
|
sock_put(sk);
|
|
inet_csk_prepare_for_destroy_sock(sk);
|
|
inet_sk(sk)->inet_num = 0;
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_prepare_forced_close);
|
|
|
|
static int inet_ulp_can_listen(const struct sock *sk)
|
|
{
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
if (icsk->icsk_ulp_ops && !icsk->icsk_ulp_ops->clone)
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int inet_csk_listen_start(struct sock *sk)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
int err;
|
|
|
|
err = inet_ulp_can_listen(sk);
|
|
if (unlikely(err))
|
|
return err;
|
|
|
|
reqsk_queue_alloc(&icsk->icsk_accept_queue);
|
|
|
|
sk->sk_ack_backlog = 0;
|
|
inet_csk_delack_init(sk);
|
|
|
|
/* There is race window here: we announce ourselves listening,
|
|
* but this transition is still not validated by get_port().
|
|
* It is OK, because this socket enters to hash table only
|
|
* after validation is complete.
|
|
*/
|
|
inet_sk_state_store(sk, TCP_LISTEN);
|
|
err = sk->sk_prot->get_port(sk, inet->inet_num);
|
|
if (!err) {
|
|
inet->inet_sport = htons(inet->inet_num);
|
|
|
|
sk_dst_reset(sk);
|
|
err = sk->sk_prot->hash(sk);
|
|
|
|
if (likely(!err))
|
|
return 0;
|
|
}
|
|
|
|
inet_sk_set_state(sk, TCP_CLOSE);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_listen_start);
|
|
|
|
static void inet_child_forget(struct sock *sk, struct request_sock *req,
|
|
struct sock *child)
|
|
{
|
|
sk->sk_prot->disconnect(child, O_NONBLOCK);
|
|
|
|
sock_orphan(child);
|
|
|
|
this_cpu_inc(*sk->sk_prot->orphan_count);
|
|
|
|
if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
|
|
BUG_ON(rcu_access_pointer(tcp_sk(child)->fastopen_rsk) != req);
|
|
BUG_ON(sk != req->rsk_listener);
|
|
|
|
/* Paranoid, to prevent race condition if
|
|
* an inbound pkt destined for child is
|
|
* blocked by sock lock in tcp_v4_rcv().
|
|
* Also to satisfy an assertion in
|
|
* tcp_v4_destroy_sock().
|
|
*/
|
|
RCU_INIT_POINTER(tcp_sk(child)->fastopen_rsk, NULL);
|
|
}
|
|
inet_csk_destroy_sock(child);
|
|
}
|
|
|
|
struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
|
|
struct request_sock *req,
|
|
struct sock *child)
|
|
{
|
|
struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
|
|
|
|
spin_lock(&queue->rskq_lock);
|
|
if (unlikely(sk->sk_state != TCP_LISTEN)) {
|
|
inet_child_forget(sk, req, child);
|
|
child = NULL;
|
|
} else {
|
|
req->sk = child;
|
|
req->dl_next = NULL;
|
|
if (queue->rskq_accept_head == NULL)
|
|
WRITE_ONCE(queue->rskq_accept_head, req);
|
|
else
|
|
queue->rskq_accept_tail->dl_next = req;
|
|
queue->rskq_accept_tail = req;
|
|
sk_acceptq_added(sk);
|
|
}
|
|
spin_unlock(&queue->rskq_lock);
|
|
return child;
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_reqsk_queue_add);
|
|
|
|
struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
|
|
struct request_sock *req, bool own_req)
|
|
{
|
|
if (own_req) {
|
|
inet_csk_reqsk_queue_drop(req->rsk_listener, req);
|
|
reqsk_queue_removed(&inet_csk(req->rsk_listener)->icsk_accept_queue, req);
|
|
|
|
if (sk != req->rsk_listener) {
|
|
/* another listening sk has been selected,
|
|
* migrate the req to it.
|
|
*/
|
|
struct request_sock *nreq;
|
|
|
|
/* hold a refcnt for the nreq->rsk_listener
|
|
* which is assigned in inet_reqsk_clone()
|
|
*/
|
|
sock_hold(sk);
|
|
nreq = inet_reqsk_clone(req, sk);
|
|
if (!nreq) {
|
|
inet_child_forget(sk, req, child);
|
|
goto child_put;
|
|
}
|
|
|
|
refcount_set(&nreq->rsk_refcnt, 1);
|
|
if (inet_csk_reqsk_queue_add(sk, nreq, child)) {
|
|
__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMIGRATEREQSUCCESS);
|
|
reqsk_migrate_reset(req);
|
|
reqsk_put(req);
|
|
return child;
|
|
}
|
|
|
|
__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMIGRATEREQFAILURE);
|
|
reqsk_migrate_reset(nreq);
|
|
__reqsk_free(nreq);
|
|
} else if (inet_csk_reqsk_queue_add(sk, req, child)) {
|
|
return child;
|
|
}
|
|
}
|
|
/* Too bad, another child took ownership of the request, undo. */
|
|
child_put:
|
|
bh_unlock_sock(child);
|
|
sock_put(child);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_complete_hashdance);
|
|
|
|
/*
|
|
* This routine closes sockets which have been at least partially
|
|
* opened, but not yet accepted.
|
|
*/
|
|
void inet_csk_listen_stop(struct sock *sk)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct request_sock_queue *queue = &icsk->icsk_accept_queue;
|
|
struct request_sock *next, *req;
|
|
|
|
/* Following specs, it would be better either to send FIN
|
|
* (and enter FIN-WAIT-1, it is normal close)
|
|
* or to send active reset (abort).
|
|
* Certainly, it is pretty dangerous while synflood, but it is
|
|
* bad justification for our negligence 8)
|
|
* To be honest, we are not able to make either
|
|
* of the variants now. --ANK
|
|
*/
|
|
while ((req = reqsk_queue_remove(queue, sk)) != NULL) {
|
|
struct sock *child = req->sk, *nsk;
|
|
struct request_sock *nreq;
|
|
|
|
local_bh_disable();
|
|
bh_lock_sock(child);
|
|
WARN_ON(sock_owned_by_user(child));
|
|
sock_hold(child);
|
|
|
|
nsk = reuseport_migrate_sock(sk, child, NULL);
|
|
if (nsk) {
|
|
nreq = inet_reqsk_clone(req, nsk);
|
|
if (nreq) {
|
|
refcount_set(&nreq->rsk_refcnt, 1);
|
|
|
|
if (inet_csk_reqsk_queue_add(nsk, nreq, child)) {
|
|
__NET_INC_STATS(sock_net(nsk),
|
|
LINUX_MIB_TCPMIGRATEREQSUCCESS);
|
|
reqsk_migrate_reset(req);
|
|
} else {
|
|
__NET_INC_STATS(sock_net(nsk),
|
|
LINUX_MIB_TCPMIGRATEREQFAILURE);
|
|
reqsk_migrate_reset(nreq);
|
|
__reqsk_free(nreq);
|
|
}
|
|
|
|
/* inet_csk_reqsk_queue_add() has already
|
|
* called inet_child_forget() on failure case.
|
|
*/
|
|
goto skip_child_forget;
|
|
}
|
|
}
|
|
|
|
inet_child_forget(sk, req, child);
|
|
skip_child_forget:
|
|
reqsk_put(req);
|
|
bh_unlock_sock(child);
|
|
local_bh_enable();
|
|
sock_put(child);
|
|
|
|
cond_resched();
|
|
}
|
|
if (queue->fastopenq.rskq_rst_head) {
|
|
/* Free all the reqs queued in rskq_rst_head. */
|
|
spin_lock_bh(&queue->fastopenq.lock);
|
|
req = queue->fastopenq.rskq_rst_head;
|
|
queue->fastopenq.rskq_rst_head = NULL;
|
|
spin_unlock_bh(&queue->fastopenq.lock);
|
|
while (req != NULL) {
|
|
next = req->dl_next;
|
|
reqsk_put(req);
|
|
req = next;
|
|
}
|
|
}
|
|
WARN_ON_ONCE(sk->sk_ack_backlog);
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
|
|
|
|
void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
|
|
{
|
|
struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
|
|
const struct inet_sock *inet = inet_sk(sk);
|
|
|
|
sin->sin_family = AF_INET;
|
|
sin->sin_addr.s_addr = inet->inet_daddr;
|
|
sin->sin_port = inet->inet_dport;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
|
|
|
|
static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl)
|
|
{
|
|
const struct inet_sock *inet = inet_sk(sk);
|
|
const struct ip_options_rcu *inet_opt;
|
|
__be32 daddr = inet->inet_daddr;
|
|
struct flowi4 *fl4;
|
|
struct rtable *rt;
|
|
|
|
rcu_read_lock();
|
|
inet_opt = rcu_dereference(inet->inet_opt);
|
|
if (inet_opt && inet_opt->opt.srr)
|
|
daddr = inet_opt->opt.faddr;
|
|
fl4 = &fl->u.ip4;
|
|
rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr,
|
|
inet->inet_saddr, inet->inet_dport,
|
|
inet->inet_sport, sk->sk_protocol,
|
|
RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
|
|
if (IS_ERR(rt))
|
|
rt = NULL;
|
|
if (rt)
|
|
sk_setup_caps(sk, &rt->dst);
|
|
rcu_read_unlock();
|
|
|
|
return &rt->dst;
|
|
}
|
|
|
|
struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu)
|
|
{
|
|
struct dst_entry *dst = __sk_dst_check(sk, 0);
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
|
|
if (!dst) {
|
|
dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
|
|
if (!dst)
|
|
goto out;
|
|
}
|
|
dst->ops->update_pmtu(dst, sk, NULL, mtu, true);
|
|
|
|
dst = __sk_dst_check(sk, 0);
|
|
if (!dst)
|
|
dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
|
|
out:
|
|
return dst;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_update_pmtu);
|