Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 787 insertions, 0 deletions

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
new file mode 100644
index 00000000..19d66cef
--- /dev/null
+++ b/net/ipv4/inet_connection_sock.c
@@ -0,0 +1,787 @@
+/*
+ * 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/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>
+#include <net/xfrm.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 struct holds the first and last local port number.
+ */
+struct local_ports sysctl_local_ports __read_mostly = {
+	.lock = __SEQLOCK_UNLOCKED(sysctl_local_ports.lock),
+	.range = { 32768, 61000 },
+};
+
+unsigned long *sysctl_local_reserved_ports;
+EXPORT_SYMBOL(sysctl_local_reserved_ports);
+
+void inet_get_local_port_range(int *low, int *high)
+{
+	unsigned seq;
+	do {
+		seq = read_seqbegin(&sysctl_local_ports.lock);
+
+		*low = sysctl_local_ports.range[0];
+		*high = sysctl_local_ports.range[1];
+	} while (read_seqretry(&sysctl_local_ports.lock, seq));
+}
+EXPORT_SYMBOL(inet_get_local_port_range);
+
+int inet_csk_bind_conflict(const struct sock *sk,
+			   const struct inet_bind_bucket *tb)
+{
+	struct sock *sk2;
+	struct hlist_node *node;
+	int reuse = sk->sk_reuse;
+
+	/*
+	 * Unlike other sk lookup places we do not check
+	 * for sk_net here, since _all_ the socks listed
+	 * in tb->owners list belong to the same net - the
+	 * one this bucket belongs to.
+	 */
+
+	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 __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2);
+				if (!sk2_rcv_saddr || !sk_rcv_saddr(sk) ||
+				    sk2_rcv_saddr == sk_rcv_saddr(sk))
+					break;
+			}
+		}
+	}
+	return node != NULL;
+}
+EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
+
+/* 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 sock *sk, unsigned short snum)
+{
+	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
+	struct inet_bind_hashbucket *head;
+	struct hlist_node *node;
+	struct inet_bind_bucket *tb;
+	int ret, attempts = 5;
+	struct net *net = sock_net(sk);
+	int smallest_size = -1, smallest_rover;
+
+	local_bh_disable();
+	if (!snum) {
+		int remaining, rover, low, high;
+
+again:
+		inet_get_local_port_range(&low, &high);
+		remaining = (high - low) + 1;
+		smallest_rover = rover = net_random() % remaining + low;
+
+		smallest_size = -1;
+		do {
+			if (inet_is_reserved_local_port(rover))
+				goto next_nolock;
+			head = &hashinfo->bhash[inet_bhashfn(net, rover,
+					hashinfo->bhash_size)];
+			spin_lock(&head->lock);
+			inet_bind_bucket_for_each(tb, node, &head->chain)
+				if (net_eq(ib_net(tb), net) && tb->port == rover) {
+					if (tb->fastreuse > 0 &&
+					    sk->sk_reuse &&
+					    sk->sk_state != TCP_LISTEN &&
+					    (tb->num_owners < smallest_size || smallest_size == -1)) {
+						smallest_size = tb->num_owners;
+						smallest_rover = rover;
+						if (atomic_read(&hashinfo->bsockets) > (high - low) + 1) {
+							snum = smallest_rover;
+							goto tb_found;
+						}
+					}
+					if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb)) {
+						snum = rover;
+						goto tb_found;
+					}
+					goto next;
+				}
+			break;
+		next:
+			spin_unlock(&head->lock);
+		next_nolock:
+			if (++rover > high)
+				rover = low;
+		} while (--remaining > 0);
+
+		/* 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) {
+			if (smallest_size != -1) {
+				snum = smallest_rover;
+				goto have_snum;
+			}
+			goto fail;
+		}
+		/* OK, here is the one we will use.  HEAD is
+		 * non-NULL and we hold it's mutex.
+		 */
+		snum = rover;
+	} else {
+have_snum:
+		head = &hashinfo->bhash[inet_bhashfn(net, snum,
+				hashinfo->bhash_size)];
+		spin_lock(&head->lock);
+		inet_bind_bucket_for_each(tb, node, &head->chain)
+			if (net_eq(ib_net(tb), net) && tb->port == snum)
+				goto tb_found;
+	}
+	tb = NULL;
+	goto tb_not_found;
+tb_found:
+	if (!hlist_empty(&tb->owners)) {
+		if (tb->fastreuse > 0 &&
+		    sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
+		    smallest_size == -1) {
+			goto success;
+		} else {
+			ret = 1;
+			if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb)) {
+				if (sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
+				    smallest_size != -1 && --attempts >= 0) {
+					spin_unlock(&head->lock);
+					goto again;
+				}
+				goto fail_unlock;
+			}
+		}
+	}
+tb_not_found:
+	ret = 1;
+	if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
+					net, 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);
+	WARN_ON(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_sleep(sk), &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_sleep(sk), &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);
+	WARN_ON(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);
+
+	setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
+			(unsigned long)sk);
+	setup_timer(&icsk->icsk_delack_timer, delack_handler,
+			(unsigned long)sk);
+	setup_timer(&sk->sk_timer, keepalive_handler, (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,
+				     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);
+
+	flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
+			   RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
+			   sk->sk_protocol, inet_sk_flowi_flags(sk),
+			   (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr,
+			   ireq->loc_addr, ireq->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 && fl4->daddr != rt->rt_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 = ireq->opt;
+	struct net *net = sock_net(sk);
+	struct flowi4 *fl4;
+	struct rtable *rt;
+
+	fl4 = &newinet->cork.fl.u.ip4;
+	flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
+			   RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
+			   sk->sk_protocol, inet_sk_flowi_flags(sk),
+			   (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr,
+			   ireq->loc_addr, ireq->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 && fl4->daddr != rt->rt_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_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->rmt_port == rport &&
+		    ireq->rmt_addr == raddr &&
+		    ireq->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)->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);
+
+/* 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->retrans >= thresh;
+		*resend = 1;
+		return;
+	}
+	*expire = req->retrans >= thresh &&
+		  (!inet_rsk(req)->acked || req->retrans >= 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->retrans >= rskq_defer_accept - 1;
+}
+
+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 3 seconds, 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);
+				if (req->rsk_ops->syn_ack_timeout)
+					req->rsk_ops->syn_ack_timeout(parent, req);
+				if (!expire &&
+				    (!resend ||
+				     !req->rsk_ops->rtx_syn_ack(parent, req, NULL) ||
+				     inet_rsk(req)->acked)) {
+					unsigned long timeo;
+
+					if (req->retrans++ == 0)
+						lopt->qlen_young--;
+					timeo = min((timeout << req->retrans), 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)->rmt_port;
+		inet_sk(newsk)->inet_num = ntohs(inet_rsk(req)->loc_port);
+		inet_sk(newsk)->inet_sport = inet_rsk(req)->loc_port;
+		newsk->sk_write_space = sk_stream_write_space;
+
+		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);
+
+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 *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);
+		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);
+
+		inet_csk_destroy_sock(child);
+
+		bh_unlock_sock(child);
+		local_bh_enable();
+		sock_put(child);
+
+		sk_acceptq_removed(sk);
+		__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