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Diffstat (limited to 'net/ipv4/inet_connection_sock.c')
-rw-r--r--net/ipv4/inet_connection_sock.c401
1 files changed, 401 insertions, 0 deletions
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
new file mode 100644
index 000000000000..2712400a8bb8
--- /dev/null
+++ b/net/ipv4/inet_connection_sock.c
@@ -0,0 +1,401 @@
+/*
+ * INET An implementation of the TCP/IP protocol suite for the LINUX
+ * operating system. INET is implemented using the BSD Socket
+ * interface as the means of communication with the user level.
+ *
+ * Support for INET connection oriented protocols.
+ *
+ * Authors: See the TCP sources
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or(at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/jhash.h>
+
+#include <net/inet_connection_sock.h>
+#include <net/inet_hashtables.h>
+#include <net/inet_timewait_sock.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/tcp_states.h>
+
+#ifdef INET_CSK_DEBUG
+const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
+EXPORT_SYMBOL(inet_csk_timer_bug_msg);
+#endif
+
+/*
+ * This array holds the first and last local port number.
+ * For high-usage systems, use sysctl to change this to
+ * 32768-61000
+ */
+int sysctl_local_port_range[2] = { 1024, 4999 };
+
+static inline int inet_csk_bind_conflict(struct sock *sk, struct inet_bind_bucket *tb)
+{
+ const u32 sk_rcv_saddr = inet_rcv_saddr(sk);
+ struct sock *sk2;
+ struct hlist_node *node;
+ int reuse = sk->sk_reuse;
+
+ sk_for_each_bound(sk2, node, &tb->owners) {
+ if (sk != sk2 &&
+ !inet_v6_ipv6only(sk2) &&
+ (!sk->sk_bound_dev_if ||
+ !sk2->sk_bound_dev_if ||
+ sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
+ if (!reuse || !sk2->sk_reuse ||
+ sk2->sk_state == TCP_LISTEN) {
+ const u32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
+ if (!sk2_rcv_saddr || !sk_rcv_saddr ||
+ sk2_rcv_saddr == sk_rcv_saddr)
+ break;
+ }
+ }
+ }
+ return node != NULL;
+}
+
+/* Obtain a reference to a local port for the given sock,
+ * if snum is zero it means select any available local port.
+ */
+int inet_csk_get_port(struct inet_hashinfo *hashinfo,
+ struct sock *sk, unsigned short snum)
+{
+ struct inet_bind_hashbucket *head;
+ struct hlist_node *node;
+ struct inet_bind_bucket *tb;
+ int ret;
+
+ local_bh_disable();
+ if (!snum) {
+ int low = sysctl_local_port_range[0];
+ int high = sysctl_local_port_range[1];
+ int remaining = (high - low) + 1;
+ int rover;
+
+ spin_lock(&hashinfo->portalloc_lock);
+ if (hashinfo->port_rover < low)
+ rover = low;
+ else
+ rover = hashinfo->port_rover;
+ do {
+ rover++;
+ if (rover > high)
+ rover = low;
+ head = &hashinfo->bhash[inet_bhashfn(rover, hashinfo->bhash_size)];
+ spin_lock(&head->lock);
+ inet_bind_bucket_for_each(tb, node, &head->chain)
+ if (tb->port == rover)
+ goto next;
+ break;
+ next:
+ spin_unlock(&head->lock);
+ } while (--remaining > 0);
+ hashinfo->port_rover = rover;
+ spin_unlock(&hashinfo->portalloc_lock);
+
+ /* Exhausted local port range during search? It is not
+ * possible for us to be holding one of the bind hash
+ * locks if this test triggers, because if 'remaining'
+ * drops to zero, we broke out of the do/while loop at
+ * the top level, not from the 'break;' statement.
+ */
+ ret = 1;
+ if (remaining <= 0)
+ goto fail;
+
+ /* OK, here is the one we will use. HEAD is
+ * non-NULL and we hold it's mutex.
+ */
+ snum = rover;
+ } else {
+ head = &hashinfo->bhash[inet_bhashfn(snum, hashinfo->bhash_size)];
+ spin_lock(&head->lock);
+ inet_bind_bucket_for_each(tb, node, &head->chain)
+ if (tb->port == snum)
+ goto tb_found;
+ }
+ tb = NULL;
+ goto tb_not_found;
+tb_found:
+ if (!hlist_empty(&tb->owners)) {
+ if (sk->sk_reuse > 1)
+ goto success;
+ if (tb->fastreuse > 0 &&
+ sk->sk_reuse && sk->sk_state != TCP_LISTEN) {
+ goto success;
+ } else {
+ ret = 1;
+ if (inet_csk_bind_conflict(sk, tb))
+ goto fail_unlock;
+ }
+ }
+tb_not_found:
+ ret = 1;
+ if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep, head, snum)) == NULL)
+ goto fail_unlock;
+ if (hlist_empty(&tb->owners)) {
+ if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
+ tb->fastreuse = 1;
+ else
+ tb->fastreuse = 0;
+ } else if (tb->fastreuse &&
+ (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
+ tb->fastreuse = 0;
+success:
+ if (!inet_csk(sk)->icsk_bind_hash)
+ inet_bind_hash(sk, tb, snum);
+ BUG_TRAP(inet_csk(sk)->icsk_bind_hash == tb);
+ ret = 0;
+
+fail_unlock:
+ spin_unlock(&head->lock);
+fail:
+ local_bh_enable();
+ 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->sk_sleep, &wait,
+ TASK_INTERRUPTIBLE);
+ release_sock(sk);
+ if (reqsk_queue_empty(&icsk->icsk_accept_queue))
+ timeo = schedule_timeout(timeo);
+ 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->sk_sleep, &wait);
+ return err;
+}
+
+/*
+ * This will accept the next outstanding connection.
+ */
+struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
+{
+ struct inet_connection_sock *icsk = inet_csk(sk);
+ 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(&icsk->icsk_accept_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;
+ }
+
+ newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
+ BUG_TRAP(newsk->sk_state != TCP_SYN_RECV);
+out:
+ release_sock(sk);
+ return newsk;
+out_err:
+ newsk = 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)(unsigned long),
+ void (*delack_handler)(unsigned long),
+ void (*keepalive_handler)(unsigned long))
+{
+ struct inet_connection_sock *icsk = inet_csk(sk);
+
+ init_timer(&icsk->icsk_retransmit_timer);
+ init_timer(&icsk->icsk_delack_timer);
+ init_timer(&sk->sk_timer);
+
+ icsk->icsk_retransmit_timer.function = retransmit_handler;
+ icsk->icsk_delack_timer.function = delack_handler;
+ sk->sk_timer.function = keepalive_handler;
+
+ icsk->icsk_retransmit_timer.data =
+ icsk->icsk_delack_timer.data =
+ sk->sk_timer.data = (unsigned long)sk;
+
+ 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 = icsk->icsk_ack.blocked = 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(struct sock *sk,
+ const struct request_sock *req)
+{
+ struct rtable *rt;
+ const struct inet_request_sock *ireq = inet_rsk(req);
+ struct ip_options *opt = inet_rsk(req)->opt;
+ struct flowi fl = { .oif = sk->sk_bound_dev_if,
+ .nl_u = { .ip4_u =
+ { .daddr = ((opt && opt->srr) ?
+ opt->faddr :
+ ireq->rmt_addr),
+ .saddr = ireq->loc_addr,
+ .tos = RT_CONN_FLAGS(sk) } },
+ .proto = sk->sk_protocol,
+ .uli_u = { .ports =
+ { .sport = inet_sk(sk)->sport,
+ .dport = ireq->rmt_port } } };
+
+ if (ip_route_output_flow(&rt, &fl, sk, 0)) {
+ IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
+ return NULL;
+ }
+ if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
+ ip_rt_put(rt);
+ IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
+ return NULL;
+ }
+ return &rt->u.dst;
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_route_req);
+
+static inline u32 inet_synq_hash(const u32 raddr, const u16 rport,
+ const u32 rnd, const u16 synq_hsize)
+{
+ return jhash_2words(raddr, (u32)rport, rnd) & (synq_hsize - 1);
+}
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+#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 __u16 rport, const __u32 raddr,
+ const __u32 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->rmt_port == rport &&
+ ireq->rmt_addr == raddr &&
+ ireq->loc_addr == laddr &&
+ AF_INET_FAMILY(req->rsk_ops->family)) {
+ BUG_TRAP(!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,
+ const unsigned 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)->rmt_addr, inet_rsk(req)->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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 13:04:17 +0100