[mirror_ubuntu-artful-kernel.git] / net / ipv4 / inet_hashtables.c

/*
 * 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.
 *
 *		Generic INET transport hashtables
 *
 * Authors:	Lotsa people, from code originally in tcp
 *
 *	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/random.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/wait.h>

#include <net/inet_connection_sock.h>
#include <net/inet_hashtables.h>
#include <net/ip.h>

/*
 * Allocate and initialize a new local port bind bucket.
 * The bindhash mutex for snum's hash chain must be held here.
 */
struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
						 struct inet_bind_hashbucket *head,
						 const unsigned short snum)
{
	struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);

	if (tb != NULL) {
		tb->port      = snum;
		tb->fastreuse = 0;
		INIT_HLIST_HEAD(&tb->owners);
		hlist_add_head(&tb->node, &head->chain);
	}
	return tb;
}

/*
 * Caller must hold hashbucket lock for this tb with local BH disabled
 */
void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
{
	if (hlist_empty(&tb->owners)) {
		__hlist_del(&tb->node);
		kmem_cache_free(cachep, tb);
	}
}

void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
		    const unsigned short snum)
{
	inet_sk(sk)->num = snum;
	sk_add_bind_node(sk, &tb->owners);
	inet_csk(sk)->icsk_bind_hash = tb;
}

/*
 * Get rid of any references to a local port held by the given sock.
 */
static void __inet_put_port(struct inet_hashinfo *hashinfo, struct sock *sk)
{
	const int bhash = inet_bhashfn(inet_sk(sk)->num, hashinfo->bhash_size);
	struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
	struct inet_bind_bucket *tb;

	spin_lock(&head->lock);
	tb = inet_csk(sk)->icsk_bind_hash;
	__sk_del_bind_node(sk);
	inet_csk(sk)->icsk_bind_hash = NULL;
	inet_sk(sk)->num = 0;
	inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
	spin_unlock(&head->lock);
}

void inet_put_port(struct inet_hashinfo *hashinfo, struct sock *sk)
{
	local_bh_disable();
	__inet_put_port(hashinfo, sk);
	local_bh_enable();
}

EXPORT_SYMBOL(inet_put_port);

/*
 * This lock without WQ_FLAG_EXCLUSIVE is good on UP and it can be very bad on SMP.
 * Look, when several writers sleep and reader wakes them up, all but one
 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
 * this, _but_ remember, it adds useless work on UP machines (wake up each
 * exclusive lock release). It should be ifdefed really.
 */
void inet_listen_wlock(struct inet_hashinfo *hashinfo)
{
	write_lock(&hashinfo->lhash_lock);

	if (atomic_read(&hashinfo->lhash_users)) {
		DEFINE_WAIT(wait);

		for (;;) {
			prepare_to_wait_exclusive(&hashinfo->lhash_wait,
						  &wait, TASK_UNINTERRUPTIBLE);
			if (!atomic_read(&hashinfo->lhash_users))
				break;
			write_unlock_bh(&hashinfo->lhash_lock);
			schedule();
			write_lock_bh(&hashinfo->lhash_lock);
		}

		finish_wait(&hashinfo->lhash_wait, &wait);
	}
}

EXPORT_SYMBOL(inet_listen_wlock);

/*
 * Don't inline this cruft. Here are some nice properties to exploit here. The
 * BSD API does not allow a listening sock to specify the remote port nor the
 * remote address for the connection. So always assume those are both
 * wildcarded during the search since they can never be otherwise.
 */
static struct sock *inet_lookup_listener_slow(const struct hlist_head *head,
					      const __be32 daddr,
					      const unsigned short hnum,
					      const int dif)
{
	struct sock *result = NULL, *sk;
	const struct hlist_node *node;
	int hiscore = -1;

	sk_for_each(sk, node, head) {
		const struct inet_sock *inet = inet_sk(sk);

		if (inet->num == hnum && !ipv6_only_sock(sk)) {
			const __be32 rcv_saddr = inet->rcv_saddr;
			int score = sk->sk_family == PF_INET ? 1 : 0;

			if (rcv_saddr) {
				if (rcv_saddr != daddr)
					continue;
				score += 2;
			}
			if (sk->sk_bound_dev_if) {
				if (sk->sk_bound_dev_if != dif)
					continue;
				score += 2;
			}
			if (score == 5)
				return sk;
			if (score > hiscore) {
				hiscore	= score;
				result	= sk;
			}
		}
	}
	return result;
}

/* Optimize the common listener case. */
struct sock *__inet_lookup_listener(struct inet_hashinfo *hashinfo,
				    const __be32 daddr, const unsigned short hnum,
				    const int dif)
{
	struct sock *sk = NULL;
	const struct hlist_head *head;

	read_lock(&hashinfo->lhash_lock);
	head = &hashinfo->listening_hash[inet_lhashfn(hnum)];
	if (!hlist_empty(head)) {
		const struct inet_sock *inet = inet_sk((sk = __sk_head(head)));

		if (inet->num == hnum && !sk->sk_node.next &&
		    (!inet->rcv_saddr || inet->rcv_saddr == daddr) &&
		    (sk->sk_family == PF_INET || !ipv6_only_sock(sk)) &&
		    !sk->sk_bound_dev_if)
			goto sherry_cache;
		sk = inet_lookup_listener_slow(head, daddr, hnum, dif);
	}
	if (sk) {
sherry_cache:
		sock_hold(sk);
	}
	read_unlock(&hashinfo->lhash_lock);
	return sk;
}
EXPORT_SYMBOL_GPL(__inet_lookup_listener);

/* called with local bh disabled */
static int __inet_check_established(struct inet_timewait_death_row *death_row,
				    struct sock *sk, __u16 lport,
				    struct inet_timewait_sock **twp)
{
	struct inet_hashinfo *hinfo = death_row->hashinfo;
	struct inet_sock *inet = inet_sk(sk);
	__be32 daddr = inet->rcv_saddr;
	__be32 saddr = inet->daddr;
	int dif = sk->sk_bound_dev_if;
	INET_ADDR_COOKIE(acookie, saddr, daddr)
	const __portpair ports = INET_COMBINED_PORTS(inet->dport, lport);
	unsigned int hash = inet_ehashfn(daddr, lport, saddr, inet->dport);
	struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
	struct sock *sk2;
	const struct hlist_node *node;
	struct inet_timewait_sock *tw;

	prefetch(head->chain.first);
	write_lock(&head->lock);

	/* Check TIME-WAIT sockets first. */
	sk_for_each(sk2, node, &head->twchain) {
		tw = inet_twsk(sk2);

		if (INET_TW_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif)) {
			if (twsk_unique(sk, sk2, twp))
				goto unique;
			else
				goto not_unique;
		}
	}
	tw = NULL;

	/* And established part... */
	sk_for_each(sk2, node, &head->chain) {
		if (INET_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif))
			goto not_unique;
	}

unique:
	/* Must record num and sport now. Otherwise we will see
	 * in hash table socket with a funny identity. */
	inet->num = lport;
	inet->sport = htons(lport);
	sk->sk_hash = hash;
	BUG_TRAP(sk_unhashed(sk));
	__sk_add_node(sk, &head->chain);
	sock_prot_inc_use(sk->sk_prot);
	write_unlock(&head->lock);

	if (twp) {
		*twp = tw;
		NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
	} else if (tw) {
		/* Silly. Should hash-dance instead... */
		inet_twsk_deschedule(tw, death_row);
		NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);

		inet_twsk_put(tw);
	}

	return 0;

not_unique:
	write_unlock(&head->lock);
	return -EADDRNOTAVAIL;
}

static inline u32 inet_sk_port_offset(const struct sock *sk)
{
	const struct inet_sock *inet = inet_sk(sk);
	return secure_ipv4_port_ephemeral(inet->rcv_saddr, inet->daddr,
					  inet->dport);
}

/*
 * Bind a port for a connect operation and hash it.
 */
int inet_hash_connect(struct inet_timewait_death_row *death_row,
		      struct sock *sk)
{
	struct inet_hashinfo *hinfo = death_row->hashinfo;
	const unsigned short snum = inet_sk(sk)->num;
	struct inet_bind_hashbucket *head;
	struct inet_bind_bucket *tb;
	int ret;

	if (!snum) {
		int low = sysctl_local_port_range[0];
		int high = sysctl_local_port_range[1];
		int range = high - low;
		int i;
		int port;
		static u32 hint;
		u32 offset = hint + inet_sk_port_offset(sk);
		struct hlist_node *node;
		struct inet_timewait_sock *tw = NULL;

		local_bh_disable();
		for (i = 1; i <= range; i++) {
			port = low + (i + offset) % range;
			head = &hinfo->bhash[inet_bhashfn(port, hinfo->bhash_size)];
			spin_lock(&head->lock);

			/* Does not bother with rcv_saddr checks,
			 * because the established check is already
			 * unique enough.
			 */
			inet_bind_bucket_for_each(tb, node, &head->chain) {
				if (tb->port == port) {
					BUG_TRAP(!hlist_empty(&tb->owners));
					if (tb->fastreuse >= 0)
						goto next_port;
					if (!__inet_check_established(death_row,
								      sk, port,
								      &tw))
						goto ok;
					goto next_port;
				}
			}

			tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, head, port);
			if (!tb) {
				spin_unlock(&head->lock);
				break;
			}
			tb->fastreuse = -1;
			goto ok;

		next_port:
			spin_unlock(&head->lock);
		}
		local_bh_enable();

		return -EADDRNOTAVAIL;

ok:
		hint += i;

		/* Head lock still held and bh's disabled */
		inet_bind_hash(sk, tb, port);
		if (sk_unhashed(sk)) {
			inet_sk(sk)->sport = htons(port);
			__inet_hash(hinfo, sk, 0);
		}
		spin_unlock(&head->lock);

		if (tw) {
			inet_twsk_deschedule(tw, death_row);
			inet_twsk_put(tw);
		}

		ret = 0;
		goto out;
	}

	head = &hinfo->bhash[inet_bhashfn(snum, hinfo->bhash_size)];
	tb  = inet_csk(sk)->icsk_bind_hash;
	spin_lock_bh(&head->lock);
	if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
		__inet_hash(hinfo, sk, 0);
		spin_unlock_bh(&head->lock);
		return 0;
	} else {
		spin_unlock(&head->lock);
		/* No definite answer... Walk to established hash table */
		ret = __inet_check_established(death_row, sk, snum, NULL);
out:
		local_bh_enable();
		return ret;
	}
}

EXPORT_SYMBOL_GPL(inet_hash_connect);
Commit	Line	Data
77d8bf9c ACM	1	/*
	2	* INET An implementation of the TCP/IP protocol suite for the LINUX
	3	* operating system. INET is implemented using the BSD Socket
	4	* interface as the means of communication with the user level.
	5	*
	6	* Generic INET transport hashtables
	7	*
	8	* Authors: Lotsa people, from code originally in tcp
	9	*
	10	* This program is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU General Public License
	12	* as published by the Free Software Foundation; either version
	13	* 2 of the License, or (at your option) any later version.
	14	*/
	15
2d8c4ce5	16	#include <linux/module.h>
a7f5e7f1	17	#include <linux/random.h>
f3f05f70	18	#include <linux/sched.h>
77d8bf9c	19	#include <linux/slab.h>
f3f05f70	20	#include <linux/wait.h>
77d8bf9c	21
463c84b9	22	#include <net/inet_connection_sock.h>
77d8bf9c	23	#include <net/inet_hashtables.h>
a7f5e7f1	24	#include <net/ip.h>
77d8bf9c ACM	25
	26	/*
	27	* Allocate and initialize a new local port bind bucket.
	28	* The bindhash mutex for snum's hash chain must be held here.
	29	*/
e18b890b	30	struct inet_bind_bucket inet_bind_bucket_create(struct kmem_cache cachep,
77d8bf9c ACM	31	struct inet_bind_hashbucket *head,
	32	const unsigned short snum)
	33	{
54e6ecb2	34	struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
77d8bf9c ACM	35
	36	if (tb != NULL) {
	37	tb->port = snum;
	38	tb->fastreuse = 0;
	39	INIT_HLIST_HEAD(&tb->owners);
	40	hlist_add_head(&tb->node, &head->chain);
	41	}
	42	return tb;
	43	}
	44
77d8bf9c ACM	45	/*
	46	* Caller must hold hashbucket lock for this tb with local BH disabled
	47	*/
e18b890b	48	void inet_bind_bucket_destroy(struct kmem_cache cachep, struct inet_bind_bucket tb)
77d8bf9c ACM	49	{
	50	if (hlist_empty(&tb->owners)) {
	51	__hlist_del(&tb->node);
	52	kmem_cache_free(cachep, tb);
	53	}
	54	}
2d8c4ce5 ACM	55
	56	void inet_bind_hash(struct sock sk, struct inet_bind_bucket tb,
	57	const unsigned short snum)
	58	{
463c84b9	59	inet_sk(sk)->num = snum;
2d8c4ce5	60	sk_add_bind_node(sk, &tb->owners);
463c84b9	61	inet_csk(sk)->icsk_bind_hash = tb;
2d8c4ce5 ACM	62	}
2d8c4ce5 ACM	63
2d8c4ce5 ACM	64	/*
	65	* Get rid of any references to a local port held by the given sock.
	66	*/
	67	static void __inet_put_port(struct inet_hashinfo hashinfo, struct sock sk)
	68	{
463c84b9	69	const int bhash = inet_bhashfn(inet_sk(sk)->num, hashinfo->bhash_size);
2d8c4ce5 ACM	70	struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
	71	struct inet_bind_bucket *tb;
	72
	73	spin_lock(&head->lock);
463c84b9	74	tb = inet_csk(sk)->icsk_bind_hash;
2d8c4ce5	75	__sk_del_bind_node(sk);
463c84b9 ACM	76	inet_csk(sk)->icsk_bind_hash = NULL;
463c84b9 ACM	77	inet_sk(sk)->num = 0;
2d8c4ce5 ACM	78	inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
	79	spin_unlock(&head->lock);
	80	}
	81
	82	void inet_put_port(struct inet_hashinfo hashinfo, struct sock sk)
	83	{
	84	local_bh_disable();
	85	__inet_put_port(hashinfo, sk);
	86	local_bh_enable();
	87	}
	88
	89	EXPORT_SYMBOL(inet_put_port);
f3f05f70 ACM	90
	91	/*
	92	* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it can be very bad on SMP.
	93	* Look, when several writers sleep and reader wakes them up, all but one
	94	* immediately hit write lock and grab all the cpus. Exclusive sleep solves
	95	* this, _but_ remember, it adds useless work on UP machines (wake up each
	96	* exclusive lock release). It should be ifdefed really.
	97	*/
	98	void inet_listen_wlock(struct inet_hashinfo *hashinfo)
	99	{
	100	write_lock(&hashinfo->lhash_lock);
	101
	102	if (atomic_read(&hashinfo->lhash_users)) {
	103	DEFINE_WAIT(wait);
	104
	105	for (;;) {
	106	prepare_to_wait_exclusive(&hashinfo->lhash_wait,
	107	&wait, TASK_UNINTERRUPTIBLE);
	108	if (!atomic_read(&hashinfo->lhash_users))
	109	break;
	110	write_unlock_bh(&hashinfo->lhash_lock);
	111	schedule();
	112	write_lock_bh(&hashinfo->lhash_lock);
	113	}
	114
	115	finish_wait(&hashinfo->lhash_wait, &wait);
	116	}
	117	}
	118
	119	EXPORT_SYMBOL(inet_listen_wlock);
33b62231 ACM	120
	121	/*
	122	* Don't inline this cruft. Here are some nice properties to exploit here. The
	123	* BSD API does not allow a listening sock to specify the remote port nor the
	124	* remote address for the connection. So always assume those are both
	125	* wildcarded during the search since they can never be otherwise.
	126	*/
8f491069	127	static struct sock inet_lookup_listener_slow(const struct hlist_head head,
fb99c848	128	const __be32 daddr,
8f491069 HX	129	const unsigned short hnum,
8f491069 HX	130	const int dif)
33b62231 ACM	131	{
	132	struct sock result = NULL, sk;
	133	const struct hlist_node *node;
	134	int hiscore = -1;
	135
	136	sk_for_each(sk, node, head) {
	137	const struct inet_sock *inet = inet_sk(sk);
	138
	139	if (inet->num == hnum && !ipv6_only_sock(sk)) {
fb99c848	140	const __be32 rcv_saddr = inet->rcv_saddr;
33b62231 ACM	141	int score = sk->sk_family == PF_INET ? 1 : 0;
	142
	143	if (rcv_saddr) {
	144	if (rcv_saddr != daddr)
	145	continue;
	146	score += 2;
	147	}
	148	if (sk->sk_bound_dev_if) {
	149	if (sk->sk_bound_dev_if != dif)
	150	continue;
	151	score += 2;
	152	}
	153	if (score == 5)
	154	return sk;
	155	if (score > hiscore) {
	156	hiscore = score;
	157	result = sk;
	158	}
	159	}
	160	}
	161	return result;
	162	}
e48c414e	163
99a92ff5	164	/* Optimize the common listener case. */
8f491069	165	struct sock __inet_lookup_listener(struct inet_hashinfo hashinfo,
fb99c848	166	const __be32 daddr, const unsigned short hnum,
8f491069	167	const int dif)
99a92ff5 HX	168	{
	169	struct sock *sk = NULL;
	170	const struct hlist_head *head;
	171
	172	read_lock(&hashinfo->lhash_lock);
	173	head = &hashinfo->listening_hash[inet_lhashfn(hnum)];
	174	if (!hlist_empty(head)) {
	175	const struct inet_sock *inet = inet_sk((sk = __sk_head(head)));
	176
	177	if (inet->num == hnum && !sk->sk_node.next &&
	178	(!inet->rcv_saddr \|\| inet->rcv_saddr == daddr) &&
	179	(sk->sk_family == PF_INET \|\| !ipv6_only_sock(sk)) &&
	180	!sk->sk_bound_dev_if)
	181	goto sherry_cache;
8f491069	182	sk = inet_lookup_listener_slow(head, daddr, hnum, dif);
99a92ff5 HX	183	}
	184	if (sk) {
	185	sherry_cache:
	186	sock_hold(sk);
	187	}
	188	read_unlock(&hashinfo->lhash_lock);
	189	return sk;
	190	}
8f491069	191	EXPORT_SYMBOL_GPL(__inet_lookup_listener);
a7f5e7f1 ACM	192
	193	/* called with local bh disabled */
	194	static int __inet_check_established(struct inet_timewait_death_row *death_row,
	195	struct sock *sk, __u16 lport,
	196	struct inet_timewait_sock **twp)
	197	{
	198	struct inet_hashinfo *hinfo = death_row->hashinfo;
	199	struct inet_sock *inet = inet_sk(sk);
fb99c848 AV	200	__be32 daddr = inet->rcv_saddr;
fb99c848 AV	201	__be32 saddr = inet->daddr;
a7f5e7f1 ACM	202	int dif = sk->sk_bound_dev_if;
a7f5e7f1 ACM	203	INET_ADDR_COOKIE(acookie, saddr, daddr)
4f765d84	204	const __portpair ports = INET_COMBINED_PORTS(inet->dport, lport);
a7f5e7f1 ACM	205	unsigned int hash = inet_ehashfn(daddr, lport, saddr, inet->dport);
	206	struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
	207	struct sock *sk2;
	208	const struct hlist_node *node;
	209	struct inet_timewait_sock *tw;
	210
	211	prefetch(head->chain.first);
	212	write_lock(&head->lock);
	213
	214	/* Check TIME-WAIT sockets first. */
dbca9b27	215	sk_for_each(sk2, node, &head->twchain) {
a7f5e7f1 ACM	216	tw = inet_twsk(sk2);
	217
	218	if (INET_TW_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif)) {
	219	if (twsk_unique(sk, sk2, twp))
	220	goto unique;
	221	else
	222	goto not_unique;
	223	}
	224	}
	225	tw = NULL;
	226
	227	/* And established part... */
	228	sk_for_each(sk2, node, &head->chain) {
	229	if (INET_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif))
	230	goto not_unique;
	231	}
	232
	233	unique:
	234	/* Must record num and sport now. Otherwise we will see
	235	* in hash table socket with a funny identity. */
	236	inet->num = lport;
	237	inet->sport = htons(lport);
	238	sk->sk_hash = hash;
	239	BUG_TRAP(sk_unhashed(sk));
	240	__sk_add_node(sk, &head->chain);
	241	sock_prot_inc_use(sk->sk_prot);
	242	write_unlock(&head->lock);
	243
	244	if (twp) {
	245	*twp = tw;
	246	NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
	247	} else if (tw) {
	248	/* Silly. Should hash-dance instead... */
	249	inet_twsk_deschedule(tw, death_row);
	250	NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
	251
	252	inet_twsk_put(tw);
	253	}
	254
	255	return 0;
	256
	257	not_unique:
	258	write_unlock(&head->lock);
	259	return -EADDRNOTAVAIL;
	260	}
	261
	262	static inline u32 inet_sk_port_offset(const struct sock *sk)
	263	{
	264	const struct inet_sock *inet = inet_sk(sk);
e905a9ed	265	return secure_ipv4_port_ephemeral(inet->rcv_saddr, inet->daddr,
a7f5e7f1 ACM	266	inet->dport);
	267	}
	268
	269	/*
	270	* Bind a port for a connect operation and hash it.
	271	*/
	272	int inet_hash_connect(struct inet_timewait_death_row *death_row,
	273	struct sock *sk)
	274	{
	275	struct inet_hashinfo *hinfo = death_row->hashinfo;
	276	const unsigned short snum = inet_sk(sk)->num;
e905a9ed YH	277	struct inet_bind_hashbucket *head;
e905a9ed YH	278	struct inet_bind_bucket *tb;
a7f5e7f1 ACM	279	int ret;
a7f5e7f1 ACM	280
e905a9ed YH	281	if (!snum) {
	282	int low = sysctl_local_port_range[0];
	283	int high = sysctl_local_port_range[1];
a7f5e7f1	284	int range = high - low;
e905a9ed	285	int i;
a7f5e7f1 ACM	286	int port;
	287	static u32 hint;
	288	u32 offset = hint + inet_sk_port_offset(sk);
	289	struct hlist_node *node;
e905a9ed	290	struct inet_timewait_sock *tw = NULL;
a7f5e7f1	291
e905a9ed	292	local_bh_disable();
a7f5e7f1 ACM	293	for (i = 1; i <= range; i++) {
a7f5e7f1 ACM	294	port = low + (i + offset) % range;
e905a9ed YH	295	head = &hinfo->bhash[inet_bhashfn(port, hinfo->bhash_size)];
e905a9ed YH	296	spin_lock(&head->lock);
a7f5e7f1	297
e905a9ed YH	298	/* Does not bother with rcv_saddr checks,
	299	* because the established check is already
	300	* unique enough.
	301	*/
a7f5e7f1	302	inet_bind_bucket_for_each(tb, node, &head->chain) {
e905a9ed YH	303	if (tb->port == port) {
	304	BUG_TRAP(!hlist_empty(&tb->owners));
	305	if (tb->fastreuse >= 0)
	306	goto next_port;
	307	if (!__inet_check_established(death_row,
a7f5e7f1 ACM	308	sk, port,
a7f5e7f1 ACM	309	&tw))
e905a9ed YH	310	goto ok;
	311	goto next_port;
	312	}
	313	}
	314
	315	tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, head, port);
	316	if (!tb) {
	317	spin_unlock(&head->lock);
	318	break;
	319	}
	320	tb->fastreuse = -1;
	321	goto ok;
	322
	323	next_port:
	324	spin_unlock(&head->lock);
	325	}
	326	local_bh_enable();
	327
	328	return -EADDRNOTAVAIL;
a7f5e7f1 ACM	329
	330	ok:
	331	hint += i;
	332
e905a9ed YH	333	/* Head lock still held and bh's disabled */
e905a9ed YH	334	inet_bind_hash(sk, tb, port);
a7f5e7f1	335	if (sk_unhashed(sk)) {
e905a9ed YH	336	inet_sk(sk)->sport = htons(port);
	337	__inet_hash(hinfo, sk, 0);
	338	}
	339	spin_unlock(&head->lock);
a7f5e7f1	340
e905a9ed YH	341	if (tw) {
	342	inet_twsk_deschedule(tw, death_row);
	343	inet_twsk_put(tw);
	344	}
a7f5e7f1 ACM	345
	346	ret = 0;
	347	goto out;
e905a9ed	348	}
a7f5e7f1	349
e905a9ed YH	350	head = &hinfo->bhash[inet_bhashfn(snum, hinfo->bhash_size)];
e905a9ed YH	351	tb = inet_csk(sk)->icsk_bind_hash;
a7f5e7f1 ACM	352	spin_lock_bh(&head->lock);
	353	if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
	354	__inet_hash(hinfo, sk, 0);
	355	spin_unlock_bh(&head->lock);
	356	return 0;
	357	} else {
	358	spin_unlock(&head->lock);
	359	/* No definite answer... Walk to established hash table */
	360	ret = __inet_check_established(death_row, sk, snum, NULL);
	361	out:
	362	local_bh_enable();
	363	return ret;
	364	}
	365	}
	366
	367	EXPORT_SYMBOL_GPL(inet_hash_connect);