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@@ -0,0 +1,401 @@
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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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+ * 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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+
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+#include <linux/config.h>
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+#include <linux/module.h>
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+#include <linux/jhash.h>
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+
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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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+
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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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+
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+/*
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+ * This array holds the first and last local port number.
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+ * For high-usage systems, use sysctl to change this to
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+ * 32768-61000
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+ */
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+int sysctl_local_port_range[2] = { 1024, 4999 };
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+
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+static inline int inet_csk_bind_conflict(struct sock *sk, struct inet_bind_bucket *tb)
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+{
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+ const u32 sk_rcv_saddr = inet_rcv_saddr(sk);
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+ struct sock *sk2;
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+ struct hlist_node *node;
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+ int reuse = sk->sk_reuse;
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+
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+ sk_for_each_bound(sk2, node, &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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+ const u32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
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+ if (!sk2_rcv_saddr || !sk_rcv_saddr ||
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+ sk2_rcv_saddr == 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 node != NULL;
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+}
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+
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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 inet_hashinfo *hashinfo,
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+ struct sock *sk, unsigned short snum)
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+{
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+ struct inet_bind_hashbucket *head;
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+ struct hlist_node *node;
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+ struct inet_bind_bucket *tb;
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+ int ret;
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+
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+ local_bh_disable();
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+ if (!snum) {
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+ int low = sysctl_local_port_range[0];
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+ int high = sysctl_local_port_range[1];
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+ int remaining = (high - low) + 1;
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+ int rover;
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+
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+ spin_lock(&hashinfo->portalloc_lock);
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+ if (hashinfo->port_rover < low)
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+ rover = low;
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+ else
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+ rover = hashinfo->port_rover;
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+ do {
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+ rover++;
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+ if (rover > high)
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+ rover = low;
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+ head = &hashinfo->bhash[inet_bhashfn(rover, hashinfo->bhash_size)];
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+ spin_lock(&head->lock);
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+ inet_bind_bucket_for_each(tb, node, &head->chain)
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+ if (tb->port == rover)
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+ goto next;
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+ break;
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+ next:
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+ spin_unlock(&head->lock);
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+ } while (--remaining > 0);
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+ hashinfo->port_rover = rover;
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+ spin_unlock(&hashinfo->portalloc_lock);
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+
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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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+ 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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+ head = &hashinfo->bhash[inet_bhashfn(snum, hashinfo->bhash_size)];
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+ spin_lock(&head->lock);
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+ inet_bind_bucket_for_each(tb, node, &head->chain)
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+ if (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 > 1)
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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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+ goto success;
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+ } else {
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+ ret = 1;
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+ if (inet_csk_bind_conflict(sk, tb))
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+ goto fail_unlock;
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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, 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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+ } else 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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+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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+ BUG_TRAP(inet_csk(sk)->icsk_bind_hash == tb);
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+ ret = 0;
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+
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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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+
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+EXPORT_SYMBOL_GPL(inet_csk_get_port);
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+
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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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+ /*
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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->sk_sleep, &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->sk_sleep, &wait);
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+ return err;
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+}
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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 sock *newsk;
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+ int error;
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+
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+ lock_sock(sk);
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+
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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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+
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+ /* Find already established connection */
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+ if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
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+ long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
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+
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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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+
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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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+
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+ newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
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+ BUG_TRAP(newsk->sk_state != TCP_SYN_RECV);
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+out:
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+ release_sock(sk);
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+ return newsk;
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+out_err:
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+ newsk = NULL;
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+ *err = error;
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+ goto out;
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+}
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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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+
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+ init_timer(&icsk->icsk_retransmit_timer);
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+ init_timer(&icsk->icsk_delack_timer);
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+ init_timer(&sk->sk_timer);
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+
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+ icsk->icsk_retransmit_timer.function = retransmit_handler;
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+ icsk->icsk_delack_timer.function = delack_handler;
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+ sk->sk_timer.function = keepalive_handler;
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+
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+ icsk->icsk_retransmit_timer.data =
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+ icsk->icsk_delack_timer.data =
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+ sk->sk_timer.data = (unsigned long)sk;
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+
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+ icsk->icsk_pending = icsk->icsk_ack.pending = 0;
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+}
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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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+
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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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+
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+EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
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+
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+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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+
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+EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
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+
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+struct dst_entry* inet_csk_route_req(struct sock *sk,
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+ const struct request_sock *req)
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+{
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+ struct rtable *rt;
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+ const struct inet_request_sock *ireq = inet_rsk(req);
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+ struct ip_options *opt = inet_rsk(req)->opt;
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+ struct flowi fl = { .oif = sk->sk_bound_dev_if,
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+ .nl_u = { .ip4_u =
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+ { .daddr = ((opt && opt->srr) ?
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+ opt->faddr :
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+ ireq->rmt_addr),
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+ .saddr = ireq->loc_addr,
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+ .tos = RT_CONN_FLAGS(sk) } },
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+ .proto = sk->sk_protocol,
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+ .uli_u = { .ports =
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+ { .sport = inet_sk(sk)->sport,
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+ .dport = ireq->rmt_port } } };
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+
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+ if (ip_route_output_flow(&rt, &fl, sk, 0)) {
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+ IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
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+ return NULL;
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+ }
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+ if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
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+ ip_rt_put(rt);
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+ IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
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+ return NULL;
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+ }
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+ return &rt->u.dst;
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+}
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+
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+EXPORT_SYMBOL_GPL(inet_csk_route_req);
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+
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+static inline u32 inet_synq_hash(const u32 raddr, const u16 rport,
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+ const u32 rnd, const u16 synq_hsize)
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+{
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+ return jhash_2words(raddr, (u32)rport, rnd) & (synq_hsize - 1);
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+}
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+
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+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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+#define AF_INET_FAMILY(fam) ((fam) == AF_INET)
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+#else
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+#define AF_INET_FAMILY(fam) 1
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+#endif
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+
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+struct request_sock *inet_csk_search_req(const struct sock *sk,
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+ struct request_sock ***prevp,
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+ const __u16 rport, const __u32 raddr,
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+ const __u32 laddr)
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+{
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+ const struct inet_connection_sock *icsk = inet_csk(sk);
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+ struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
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+ struct request_sock *req, **prev;
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+
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+ for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
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+ lopt->nr_table_entries)];
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+ (req = *prev) != NULL;
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+ prev = &req->dl_next) {
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+ const struct inet_request_sock *ireq = inet_rsk(req);
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+
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+ if (ireq->rmt_port == rport &&
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+ ireq->rmt_addr == raddr &&
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+ ireq->loc_addr == laddr &&
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+ AF_INET_FAMILY(req->rsk_ops->family)) {
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+ BUG_TRAP(!req->sk);
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+ *prevp = prev;
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+ break;
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+ }
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+ }
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+
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+ return req;
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+}
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+
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+EXPORT_SYMBOL_GPL(inet_csk_search_req);
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+
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+void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
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+ const unsigned timeout)
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+{
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+ struct inet_connection_sock *icsk = inet_csk(sk);
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+ struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
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+ const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
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+ lopt->hash_rnd, lopt->nr_table_entries);
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+
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+ reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
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+ inet_csk_reqsk_queue_added(sk, timeout);
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+}
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+
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+EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
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Arnaldo Carvalho de Melo