758 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			758 lines
		
	
	
		
			20 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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 | 
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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 struct holds the first and last local port number.
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 */
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struct local_ports sysctl_local_ports __read_mostly = {
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	.lock = SEQLOCK_UNLOCKED,
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	.range = { 32768, 61000 },
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};
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void inet_get_local_port_range(int *low, int *high)
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{
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	unsigned seq;
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	do {
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		seq = read_seqbegin(&sysctl_local_ports.lock);
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		*low = sysctl_local_ports.range[0];
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		*high = sysctl_local_ports.range[1];
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	} while (read_seqretry(&sysctl_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)
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{
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	const __be32 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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	 * 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, 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 __be32 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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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 hlist_node *node;
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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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	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(&low, &high);
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		remaining = (high - low) + 1;
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		smallest_rover = rover = net_random() % remaining + low;
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		smallest_size = -1;
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		do {
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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, node, &head->chain)
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				if (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->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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							spin_unlock(&head->lock);
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							snum = smallest_rover;
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							goto have_snum;
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						}
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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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			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, node, &head->chain)
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			if (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 (tb->fastreuse > 0 &&
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		    sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
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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)) {
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				if (sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
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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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	} 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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	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->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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 * 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 */
 | 
						|
	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;
 | 
						|
		if (!timeo)
 | 
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			goto out_err;
 | 
						|
 | 
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		error = inet_csk_wait_for_connect(sk, timeo);
 | 
						|
		if (error)
 | 
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			goto out_err;
 | 
						|
	}
 | 
						|
 | 
						|
	newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
 | 
						|
	WARN_ON(newsk->sk_state == TCP_SYN_RECV);
 | 
						|
out:
 | 
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	release_sock(sk);
 | 
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	return newsk;
 | 
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out_err:
 | 
						|
	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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	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);
 | 
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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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 | 
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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)
 | 
						|
{
 | 
						|
	struct inet_connection_sock *icsk = inet_csk(sk);
 | 
						|
 | 
						|
	icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
 | 
						|
 | 
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	sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 | 
						|
	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)
 | 
						|
{
 | 
						|
	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)
 | 
						|
{
 | 
						|
	sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
 | 
						|
}
 | 
						|
 | 
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EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
 | 
						|
 | 
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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 =
 | 
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				      { .daddr = ((opt && opt->srr) ?
 | 
						|
						  opt->faddr :
 | 
						|
						  ireq->rmt_addr),
 | 
						|
					.saddr = ireq->loc_addr,
 | 
						|
					.tos = RT_CONN_FLAGS(sk) } },
 | 
						|
			    .proto = sk->sk_protocol,
 | 
						|
			    .flags = inet_sk_flowi_flags(sk),
 | 
						|
			    .uli_u = { .ports =
 | 
						|
				       { .sport = inet_sk(sk)->sport,
 | 
						|
					 .dport = ireq->rmt_port } } };
 | 
						|
	struct net *net = sock_net(sk);
 | 
						|
 | 
						|
	security_req_classify_flow(req, &fl);
 | 
						|
	if (ip_route_output_flow(net, &rt, &fl, sk, 0))
 | 
						|
		goto no_route;
 | 
						|
	if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
 | 
						|
		goto route_err;
 | 
						|
	return &rt->u.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);
 | 
						|
 | 
						|
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 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 __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);
 | 
						|
}
 | 
						|
 | 
						|
/* Only thing we need from tcp.h */
 | 
						|
extern int sysctl_tcp_synack_retries;
 | 
						|
 | 
						|
EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
 | 
						|
 | 
						|
/* 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 (!expire &&
 | 
						|
				    (!resend ||
 | 
						|
				     !req->rsk_ops->rtx_syn_ack(parent, req) ||
 | 
						|
				     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);
 | 
						|
 | 
						|
struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
 | 
						|
			    const gfp_t priority)
 | 
						|
{
 | 
						|
	struct sock *newsk = sk_clone(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)->dport = inet_rsk(req)->rmt_port;
 | 
						|
		inet_sk(newsk)->num = ntohs(inet_rsk(req)->loc_port);
 | 
						|
		inet_sk(newsk)->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);
 | 
						|
 | 
						|
/*
 | 
						|
 * 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)->num, it must be bound */
 | 
						|
	WARN_ON(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);
 | 
						|
 | 
						|
	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->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);
 | 
						|
		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->daddr;
 | 
						|
	sin->sin_port		= 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
 |