![Eric Dumazet](/assets/img/avatar_default.png)
A long standing problem in netlink socket dumps is the use of kernel socket addresses as cookies. 1) It is a security concern. 2) Sockets can be reused quite quickly, so there is no guarantee a cookie is used once and identify a flow. 3) request sock, establish sock, and timewait socks for a given flow have different cookies. Part of our effort to bring better TCP statistics requires to switch to a different allocator. In this patch, I chose to use a per network namespace 64bit generator, and to use it only in the case a socket needs to be dumped to netlink. (This might be refined later if needed) Note that I tried to carry cookies from request sock, to establish sock, then timewait sockets. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Eric Salo <salo@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
941 lines
26 KiB
C
941 lines
26 KiB
C
/*
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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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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or(at your option) any later version.
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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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#ifdef INET_CSK_DEBUG
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const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
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EXPORT_SYMBOL(inet_csk_timer_bug_msg);
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#endif
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void inet_get_local_port_range(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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int inet_csk_bind_conflict(const struct sock *sk,
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const struct inet_bind_bucket *tb, bool relax)
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{
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struct sock *sk2;
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int reuse = sk->sk_reuse;
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int reuseport = sk->sk_reuseport;
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kuid_t uid = sock_i_uid((struct sock *)sk);
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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 list belong to the same net - the
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* one this bucket belongs to.
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*/
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sk_for_each_bound(sk2, &tb->owners) {
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if (sk != sk2 &&
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!inet_v6_ipv6only(sk2) &&
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(!sk->sk_bound_dev_if ||
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!sk2->sk_bound_dev_if ||
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sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
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if ((!reuse || !sk2->sk_reuse ||
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sk2->sk_state == TCP_LISTEN) &&
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(!reuseport || !sk2->sk_reuseport ||
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(sk2->sk_state != TCP_TIME_WAIT &&
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!uid_eq(uid, sock_i_uid(sk2))))) {
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if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr ||
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sk2->sk_rcv_saddr == sk->sk_rcv_saddr)
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break;
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}
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if (!relax && reuse && sk2->sk_reuse &&
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sk2->sk_state != TCP_LISTEN) {
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if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr ||
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sk2->sk_rcv_saddr == sk->sk_rcv_saddr)
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break;
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}
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}
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}
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return sk2 != NULL;
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}
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EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
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/* Obtain a reference to a local port for the given sock,
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* if snum is zero it means select any available local port.
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*/
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int inet_csk_get_port(struct sock *sk, unsigned short snum)
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{
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struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
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struct inet_bind_hashbucket *head;
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struct inet_bind_bucket *tb;
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int ret, attempts = 5;
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struct net *net = sock_net(sk);
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int smallest_size = -1, smallest_rover;
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kuid_t uid = sock_i_uid(sk);
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local_bh_disable();
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if (!snum) {
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int remaining, rover, low, high;
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again:
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inet_get_local_port_range(net, &low, &high);
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remaining = (high - low) + 1;
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smallest_rover = rover = prandom_u32() % remaining + low;
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smallest_size = -1;
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do {
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if (inet_is_local_reserved_port(net, rover))
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goto next_nolock;
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head = &hashinfo->bhash[inet_bhashfn(net, rover,
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hashinfo->bhash_size)];
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spin_lock(&head->lock);
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inet_bind_bucket_for_each(tb, &head->chain)
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if (net_eq(ib_net(tb), net) && tb->port == rover) {
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if (((tb->fastreuse > 0 &&
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sk->sk_reuse &&
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sk->sk_state != TCP_LISTEN) ||
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(tb->fastreuseport > 0 &&
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sk->sk_reuseport &&
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uid_eq(tb->fastuid, uid))) &&
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(tb->num_owners < smallest_size || smallest_size == -1)) {
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smallest_size = tb->num_owners;
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smallest_rover = rover;
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if (atomic_read(&hashinfo->bsockets) > (high - low) + 1 &&
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!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) {
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snum = smallest_rover;
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goto tb_found;
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}
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}
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if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) {
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snum = rover;
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goto tb_found;
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}
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goto next;
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}
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break;
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next:
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spin_unlock(&head->lock);
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next_nolock:
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if (++rover > high)
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rover = low;
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} while (--remaining > 0);
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/* Exhausted local port range during search? It is not
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* possible for us to be holding one of the bind hash
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* locks if this test triggers, because if 'remaining'
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* drops to zero, we broke out of the do/while loop at
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* the top level, not from the 'break;' statement.
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*/
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ret = 1;
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if (remaining <= 0) {
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if (smallest_size != -1) {
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snum = smallest_rover;
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goto have_snum;
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}
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goto fail;
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}
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/* OK, here is the one we will use. HEAD is
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* non-NULL and we hold it's mutex.
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*/
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snum = rover;
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} else {
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have_snum:
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head = &hashinfo->bhash[inet_bhashfn(net, snum,
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hashinfo->bhash_size)];
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spin_lock(&head->lock);
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inet_bind_bucket_for_each(tb, &head->chain)
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if (net_eq(ib_net(tb), net) && tb->port == snum)
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goto tb_found;
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}
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tb = NULL;
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goto tb_not_found;
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tb_found:
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if (!hlist_empty(&tb->owners)) {
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if (sk->sk_reuse == SK_FORCE_REUSE)
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goto success;
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if (((tb->fastreuse > 0 &&
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sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
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(tb->fastreuseport > 0 &&
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sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
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smallest_size == -1) {
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goto success;
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} else {
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ret = 1;
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if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) {
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if (((sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
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(tb->fastreuseport > 0 &&
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sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
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smallest_size != -1 && --attempts >= 0) {
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spin_unlock(&head->lock);
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goto again;
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}
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goto fail_unlock;
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}
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}
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}
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tb_not_found:
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ret = 1;
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if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
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net, head, snum)) == NULL)
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goto fail_unlock;
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if (hlist_empty(&tb->owners)) {
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if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
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tb->fastreuse = 1;
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else
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tb->fastreuse = 0;
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if (sk->sk_reuseport) {
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tb->fastreuseport = 1;
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tb->fastuid = uid;
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} else
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tb->fastreuseport = 0;
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} else {
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if (tb->fastreuse &&
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(!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
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tb->fastreuse = 0;
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if (tb->fastreuseport &&
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(!sk->sk_reuseport || !uid_eq(tb->fastuid, uid)))
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tb->fastreuseport = 0;
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}
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success:
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if (!inet_csk(sk)->icsk_bind_hash)
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inet_bind_hash(sk, tb, snum);
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WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
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ret = 0;
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fail_unlock:
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spin_unlock(&head->lock);
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fail:
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local_bh_enable();
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return ret;
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}
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EXPORT_SYMBOL_GPL(inet_csk_get_port);
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/*
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* Wait for an incoming connection, avoid race conditions. This must be called
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* with the socket locked.
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*/
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static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
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{
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struct inet_connection_sock *icsk = inet_csk(sk);
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DEFINE_WAIT(wait);
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int err;
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/*
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* True wake-one mechanism for incoming connections: only
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* one process gets woken up, not the 'whole herd'.
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* Since we do not 'race & poll' for established sockets
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* anymore, the common case will execute the loop only once.
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*
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* Subtle issue: "add_wait_queue_exclusive()" will be added
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* after any current non-exclusive waiters, and we know that
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* it will always _stay_ after any new non-exclusive waiters
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* because all non-exclusive waiters are added at the
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* beginning of the wait-queue. As such, it's ok to "drop"
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* our exclusiveness temporarily when we get woken up without
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* having to remove and re-insert us on the wait queue.
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*/
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for (;;) {
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prepare_to_wait_exclusive(sk_sleep(sk), &wait,
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TASK_INTERRUPTIBLE);
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release_sock(sk);
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if (reqsk_queue_empty(&icsk->icsk_accept_queue))
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timeo = schedule_timeout(timeo);
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lock_sock(sk);
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err = 0;
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if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
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break;
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err = -EINVAL;
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if (sk->sk_state != TCP_LISTEN)
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break;
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err = sock_intr_errno(timeo);
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if (signal_pending(current))
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break;
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err = -EAGAIN;
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if (!timeo)
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break;
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}
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finish_wait(sk_sleep(sk), &wait);
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return err;
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}
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/*
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* This will accept the next outstanding connection.
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*/
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struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
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{
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struct inet_connection_sock *icsk = inet_csk(sk);
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struct request_sock_queue *queue = &icsk->icsk_accept_queue;
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struct sock *newsk;
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struct request_sock *req;
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int error;
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lock_sock(sk);
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/* We need to make sure that this socket is listening,
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* and that it has something pending.
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*/
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error = -EINVAL;
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if (sk->sk_state != TCP_LISTEN)
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goto out_err;
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/* Find already established connection */
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if (reqsk_queue_empty(queue)) {
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long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
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/* If this is a non blocking socket don't sleep */
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error = -EAGAIN;
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if (!timeo)
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goto out_err;
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error = inet_csk_wait_for_connect(sk, timeo);
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if (error)
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goto out_err;
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}
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req = reqsk_queue_remove(queue);
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newsk = req->sk;
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sk_acceptq_removed(sk);
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if (sk->sk_protocol == IPPROTO_TCP && queue->fastopenq != NULL) {
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spin_lock_bh(&queue->fastopenq->lock);
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if (tcp_rsk(req)->listener) {
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/* We are still waiting for the final ACK from 3WHS
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* so can't free req now. Instead, we set req->sk to
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* NULL to signify that the child socket is taken
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* so reqsk_fastopen_remove() will free the req
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* when 3WHS finishes (or is aborted).
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*/
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req->sk = NULL;
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req = NULL;
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}
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spin_unlock_bh(&queue->fastopenq->lock);
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}
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out:
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release_sock(sk);
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if (req)
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__reqsk_free(req);
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return newsk;
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out_err:
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newsk = NULL;
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req = NULL;
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*err = error;
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goto out;
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}
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EXPORT_SYMBOL(inet_csk_accept);
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|
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/*
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* Using different timers for retransmit, delayed acks and probes
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* We may wish use just one timer maintaining a list of expire jiffies
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* to optimize.
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*/
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void inet_csk_init_xmit_timers(struct sock *sk,
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void (*retransmit_handler)(unsigned long),
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void (*delack_handler)(unsigned long),
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void (*keepalive_handler)(unsigned long))
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{
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struct inet_connection_sock *icsk = inet_csk(sk);
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setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
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(unsigned long)sk);
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setup_timer(&icsk->icsk_delack_timer, delack_handler,
|
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(unsigned long)sk);
|
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setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
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icsk->icsk_pending = icsk->icsk_ack.pending = 0;
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}
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EXPORT_SYMBOL(inet_csk_init_xmit_timers);
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|
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void inet_csk_clear_xmit_timers(struct sock *sk)
|
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{
|
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struct inet_connection_sock *icsk = inet_csk(sk);
|
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|
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icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
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|
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sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
|
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sk_stop_timer(sk, &icsk->icsk_delack_timer);
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sk_stop_timer(sk, &sk->sk_timer);
|
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}
|
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EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
|
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|
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void inet_csk_delete_keepalive_timer(struct sock *sk)
|
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{
|
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sk_stop_timer(sk, &sk->sk_timer);
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}
|
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EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
|
|
|
|
void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
|
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{
|
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sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
|
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}
|
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EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
|
|
|
|
struct dst_entry *inet_csk_route_req(struct sock *sk,
|
|
struct flowi4 *fl4,
|
|
const struct request_sock *req)
|
|
{
|
|
struct rtable *rt;
|
|
const struct inet_request_sock *ireq = inet_rsk(req);
|
|
struct ip_options_rcu *opt = inet_rsk(req)->opt;
|
|
struct net *net = sock_net(sk);
|
|
int flags = inet_sk_flowi_flags(sk);
|
|
|
|
flowi4_init_output(fl4, sk->sk_bound_dev_if, ireq->ir_mark,
|
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RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
|
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sk->sk_protocol,
|
|
flags,
|
|
(opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
|
|
ireq->ir_loc_addr, ireq->ir_rmt_port, inet_sk(sk)->inet_sport);
|
|
security_req_classify_flow(req, flowi4_to_flowi(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_BH(net, IPSTATS_MIB_OUTNOROUTES);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_route_req);
|
|
|
|
struct dst_entry *inet_csk_route_child_sock(struct sock *sk,
|
|
struct sock *newsk,
|
|
const struct request_sock *req)
|
|
{
|
|
const struct inet_request_sock *ireq = inet_rsk(req);
|
|
struct inet_sock *newinet = inet_sk(newsk);
|
|
struct ip_options_rcu *opt;
|
|
struct net *net = sock_net(sk);
|
|
struct flowi4 *fl4;
|
|
struct rtable *rt;
|
|
|
|
fl4 = &newinet->cork.fl.u.ip4;
|
|
|
|
rcu_read_lock();
|
|
opt = rcu_dereference(newinet->inet_opt);
|
|
flowi4_init_output(fl4, sk->sk_bound_dev_if, inet_rsk(req)->ir_mark,
|
|
RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
|
|
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, inet_sk(sk)->inet_sport);
|
|
security_req_classify_flow(req, flowi4_to_flowi(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_BH(net, IPSTATS_MIB_OUTNOROUTES);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
|
|
|
|
static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
|
|
const u32 rnd, const u32 synq_hsize)
|
|
{
|
|
return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
#define AF_INET_FAMILY(fam) ((fam) == AF_INET)
|
|
#else
|
|
#define AF_INET_FAMILY(fam) 1
|
|
#endif
|
|
|
|
struct request_sock *inet_csk_search_req(const struct sock *sk,
|
|
struct request_sock ***prevp,
|
|
const __be16 rport, const __be32 raddr,
|
|
const __be32 laddr)
|
|
{
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
|
|
struct request_sock *req, **prev;
|
|
|
|
for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
|
|
lopt->nr_table_entries)];
|
|
(req = *prev) != NULL;
|
|
prev = &req->dl_next) {
|
|
const struct inet_request_sock *ireq = inet_rsk(req);
|
|
|
|
if (ireq->ir_rmt_port == rport &&
|
|
ireq->ir_rmt_addr == raddr &&
|
|
ireq->ir_loc_addr == laddr &&
|
|
AF_INET_FAMILY(req->rsk_ops->family)) {
|
|
WARN_ON(req->sk);
|
|
*prevp = prev;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return req;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_search_req);
|
|
|
|
void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
|
|
unsigned long timeout)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
|
|
const u32 h = inet_synq_hash(inet_rsk(req)->ir_rmt_addr,
|
|
inet_rsk(req)->ir_rmt_port,
|
|
lopt->hash_rnd, lopt->nr_table_entries);
|
|
|
|
reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
|
|
inet_csk_reqsk_queue_added(sk, timeout);
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
|
|
|
|
/* Only thing we need from tcp.h */
|
|
extern int sysctl_tcp_synack_retries;
|
|
|
|
|
|
/* Decide when to expire the request and when to resend SYN-ACK */
|
|
static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
|
|
const int max_retries,
|
|
const u8 rskq_defer_accept,
|
|
int *expire, int *resend)
|
|
{
|
|
if (!rskq_defer_accept) {
|
|
*expire = req->num_timeout >= thresh;
|
|
*resend = 1;
|
|
return;
|
|
}
|
|
*expire = req->num_timeout >= thresh &&
|
|
(!inet_rsk(req)->acked || req->num_timeout >= max_retries);
|
|
/*
|
|
* 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(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);
|
|
|
|
void inet_csk_reqsk_queue_prune(struct sock *parent,
|
|
const unsigned long interval,
|
|
const unsigned long timeout,
|
|
const unsigned long max_rto)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(parent);
|
|
struct request_sock_queue *queue = &icsk->icsk_accept_queue;
|
|
struct listen_sock *lopt = queue->listen_opt;
|
|
int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
|
|
int thresh = max_retries;
|
|
unsigned long now = jiffies;
|
|
struct request_sock **reqp, *req;
|
|
int i, budget;
|
|
|
|
if (lopt == NULL || lopt->qlen == 0)
|
|
return;
|
|
|
|
/* 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.
|
|
*/
|
|
if (lopt->qlen>>(lopt->max_qlen_log-1)) {
|
|
int young = (lopt->qlen_young<<1);
|
|
|
|
while (thresh > 2) {
|
|
if (lopt->qlen < young)
|
|
break;
|
|
thresh--;
|
|
young <<= 1;
|
|
}
|
|
}
|
|
|
|
if (queue->rskq_defer_accept)
|
|
max_retries = queue->rskq_defer_accept;
|
|
|
|
budget = 2 * (lopt->nr_table_entries / (timeout / interval));
|
|
i = lopt->clock_hand;
|
|
|
|
do {
|
|
reqp=&lopt->syn_table[i];
|
|
while ((req = *reqp) != NULL) {
|
|
if (time_after_eq(now, req->expires)) {
|
|
int expire = 0, resend = 0;
|
|
|
|
syn_ack_recalc(req, thresh, max_retries,
|
|
queue->rskq_defer_accept,
|
|
&expire, &resend);
|
|
req->rsk_ops->syn_ack_timeout(parent, req);
|
|
if (!expire &&
|
|
(!resend ||
|
|
!inet_rtx_syn_ack(parent, req) ||
|
|
inet_rsk(req)->acked)) {
|
|
unsigned long timeo;
|
|
|
|
if (req->num_timeout++ == 0)
|
|
lopt->qlen_young--;
|
|
timeo = min(timeout << req->num_timeout,
|
|
max_rto);
|
|
req->expires = now + timeo;
|
|
reqp = &req->dl_next;
|
|
continue;
|
|
}
|
|
|
|
/* Drop this request */
|
|
inet_csk_reqsk_queue_unlink(parent, req, reqp);
|
|
reqsk_queue_removed(queue, req);
|
|
reqsk_free(req);
|
|
continue;
|
|
}
|
|
reqp = &req->dl_next;
|
|
}
|
|
|
|
i = (i + 1) & (lopt->nr_table_entries - 1);
|
|
|
|
} while (--budget > 0);
|
|
|
|
lopt->clock_hand = i;
|
|
|
|
if (lopt->qlen)
|
|
inet_csk_reset_keepalive_timer(parent, interval);
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
|
|
|
|
/**
|
|
* 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 != NULL) {
|
|
struct inet_connection_sock *newicsk = inet_csk(newsk);
|
|
|
|
newsk->sk_state = TCP_SYN_RECV;
|
|
newicsk->icsk_bind_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);
|
|
newsk->sk_write_space = sk_stream_write_space;
|
|
|
|
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;
|
|
|
|
/* Deinitialize accept_queue to trap illegal accesses. */
|
|
memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
|
|
|
|
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);
|
|
|
|
sk_refcnt_debug_release(sk);
|
|
|
|
percpu_counter_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);
|
|
|
|
/* The below has to be done to allow calling inet_csk_destroy_sock */
|
|
sock_set_flag(sk, SOCK_DEAD);
|
|
percpu_counter_inc(sk->sk_prot->orphan_count);
|
|
inet_sk(sk)->inet_num = 0;
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_prepare_forced_close);
|
|
|
|
int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
|
|
{
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
|
|
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
sk->sk_max_ack_backlog = 0;
|
|
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.
|
|
*/
|
|
sk->sk_state = TCP_LISTEN;
|
|
if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
|
|
inet->inet_sport = htons(inet->inet_num);
|
|
|
|
sk_dst_reset(sk);
|
|
sk->sk_prot->hash(sk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
sk->sk_state = TCP_CLOSE;
|
|
__reqsk_queue_destroy(&icsk->icsk_accept_queue);
|
|
return -EADDRINUSE;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_listen_start);
|
|
|
|
/*
|
|
* 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 *acc_req;
|
|
struct request_sock *req;
|
|
|
|
inet_csk_delete_keepalive_timer(sk);
|
|
|
|
/* make all the listen_opt local to us */
|
|
acc_req = reqsk_queue_yank_acceptq(queue);
|
|
|
|
/* 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
|
|
*/
|
|
reqsk_queue_destroy(queue);
|
|
|
|
while ((req = acc_req) != NULL) {
|
|
struct sock *child = req->sk;
|
|
|
|
acc_req = req->dl_next;
|
|
|
|
local_bh_disable();
|
|
bh_lock_sock(child);
|
|
WARN_ON(sock_owned_by_user(child));
|
|
sock_hold(child);
|
|
|
|
sk->sk_prot->disconnect(child, O_NONBLOCK);
|
|
|
|
sock_orphan(child);
|
|
|
|
percpu_counter_inc(sk->sk_prot->orphan_count);
|
|
|
|
if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->listener) {
|
|
BUG_ON(tcp_sk(child)->fastopen_rsk != req);
|
|
BUG_ON(sk != tcp_rsk(req)->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().
|
|
*/
|
|
tcp_sk(child)->fastopen_rsk = NULL;
|
|
sock_put(sk);
|
|
}
|
|
inet_csk_destroy_sock(child);
|
|
|
|
bh_unlock_sock(child);
|
|
local_bh_enable();
|
|
sock_put(child);
|
|
|
|
sk_acceptq_removed(sk);
|
|
__reqsk_free(req);
|
|
}
|
|
if (queue->fastopenq != NULL) {
|
|
/* Free all the reqs queued in rskq_rst_head. */
|
|
spin_lock_bh(&queue->fastopenq->lock);
|
|
acc_req = queue->fastopenq->rskq_rst_head;
|
|
queue->fastopenq->rskq_rst_head = NULL;
|
|
spin_unlock_bh(&queue->fastopenq->lock);
|
|
while ((req = acc_req) != NULL) {
|
|
acc_req = req->dl_next;
|
|
__reqsk_free(req);
|
|
}
|
|
}
|
|
WARN_ON(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);
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
|
|
char __user *optval, int __user *optlen)
|
|
{
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
if (icsk->icsk_af_ops->compat_getsockopt != NULL)
|
|
return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
|
|
optval, optlen);
|
|
return icsk->icsk_af_ops->getsockopt(sk, level, optname,
|
|
optval, optlen);
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
|
|
|
|
int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
|
|
char __user *optval, unsigned int optlen)
|
|
{
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
if (icsk->icsk_af_ops->compat_setsockopt != NULL)
|
|
return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
|
|
optval, optlen);
|
|
return icsk->icsk_af_ops->setsockopt(sk, level, optname,
|
|
optval, optlen);
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
|
|
#endif
|
|
|
|
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);
|
|
|
|
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);
|