+
+/*
+ * 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)
+{
+ BUG_TRAP(sk->sk_state == TCP_CLOSE);
+ BUG_TRAP(sock_flag(sk, SOCK_DEAD));
+
+ /* It cannot be in hash table! */
+ BUG_TRAP(sk_unhashed(sk));
+
+ /* If it has not 0 inet_sk(sk)->num, it must be bound */
+ BUG_TRAP(!inet_sk(sk)->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);
+
+ atomic_dec(sk->sk_prot->orphan_count);
+ sock_put(sk);
+}
+
+EXPORT_SYMBOL(inet_csk_destroy_sock);
+
+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->num)) {
+ inet->sport = htons(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 *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(&icsk->icsk_accept_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(&icsk->icsk_accept_queue);
+
+ while ((req = acc_req) != NULL) {
+ struct sock *child = req->sk;
+
+ acc_req = req->dl_next;
+
+ local_bh_disable();
+ bh_lock_sock(child);
+ BUG_TRAP(!sock_owned_by_user(child));
+ sock_hold(child);
+
+ sk->sk_prot->disconnect(child, O_NONBLOCK);
+
+ sock_orphan(child);
+
+ atomic_inc(sk->sk_prot->orphan_count);
+
+ inet_csk_destroy_sock(child);
+
+ bh_unlock_sock(child);
+ local_bh_enable();
+ sock_put(child);
+
+ sk_acceptq_removed(sk);
+ __reqsk_free(req);
+ }
+ BUG_TRAP(!sk->sk_ack_backlog);
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_listen_stop);