[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv6 / inet6_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 INET6 transport hashtables
 *
 * Authors:	Lotsa people, from code originally in tcp, generalised here
 * 		by Arnaldo Carvalho de Melo <acme@mandriva.com>
 *
 *	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 <net/inet_connection_sock.h>
#include <net/inet_hashtables.h>
#include <net/inet6_hashtables.h>
#include <net/ip.h>

void __inet6_hash(struct inet_hashinfo *hashinfo,
				struct sock *sk)
{
	struct hlist_head *list;
	rwlock_t *lock;

	BUG_TRAP(sk_unhashed(sk));

	if (sk->sk_state == TCP_LISTEN) {
		list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
		lock = &hashinfo->lhash_lock;
		inet_listen_wlock(hashinfo);
	} else {
		unsigned int hash;
		sk->sk_hash = hash = inet6_sk_ehashfn(sk);
		list = &inet_ehash_bucket(hashinfo, hash)->chain;
		lock = inet_ehash_lockp(hashinfo, hash);
		write_lock(lock);
	}

	__sk_add_node(sk, list);
	sock_prot_inuse_add(sk->sk_prot, 1);
	write_unlock(lock);
}
EXPORT_SYMBOL(__inet6_hash);

/*
 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
 *
 * The sockhash lock must be held as a reader here.
 */
struct sock *__inet6_lookup_established(struct inet_hashinfo *hashinfo,
					   const struct in6_addr *saddr,
					   const __be16 sport,
					   const struct in6_addr *daddr,
					   const u16 hnum,
					   const int dif)
{
	struct sock *sk;
	const struct hlist_node *node;
	const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
	/* Optimize here for direct hit, only listening connections can
	 * have wildcards anyways.
	 */
	unsigned int hash = inet6_ehashfn(daddr, hnum, saddr, sport);
	struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash);
	rwlock_t *lock = inet_ehash_lockp(hashinfo, hash);

	prefetch(head->chain.first);
	read_lock(lock);
	sk_for_each(sk, node, &head->chain) {
		/* For IPV6 do the cheaper port and family tests first. */
		if (INET6_MATCH(sk, hash, saddr, daddr, ports, dif))
			goto hit; /* You sunk my battleship! */
	}
	/* Must check for a TIME_WAIT'er before going to listener hash. */
	sk_for_each(sk, node, &head->twchain) {
		if (INET6_TW_MATCH(sk, hash, saddr, daddr, ports, dif))
			goto hit;
	}
	read_unlock(lock);
	return NULL;

hit:
	sock_hold(sk);
	read_unlock(lock);
	return sk;
}
EXPORT_SYMBOL(__inet6_lookup_established);

struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo,
				   const struct in6_addr *daddr,
				   const unsigned short hnum, const int dif)
{
	struct sock *sk;
	const struct hlist_node *node;
	struct sock *result = NULL;
	int score, hiscore = 0;

	read_lock(&hashinfo->lhash_lock);
	sk_for_each(sk, node, &hashinfo->listening_hash[inet_lhashfn(hnum)]) {
		if (inet_sk(sk)->num == hnum && sk->sk_family == PF_INET6) {
			const struct ipv6_pinfo *np = inet6_sk(sk);

			score = 1;
			if (!ipv6_addr_any(&np->rcv_saddr)) {
				if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
					continue;
				score++;
			}
			if (sk->sk_bound_dev_if) {
				if (sk->sk_bound_dev_if != dif)
					continue;
				score++;
			}
			if (score == 3) {
				result = sk;
				break;
			}
			if (score > hiscore) {
				hiscore = score;
				result = sk;
			}
		}
	}
	if (result)
		sock_hold(result);
	read_unlock(&hashinfo->lhash_lock);
	return result;
}

EXPORT_SYMBOL_GPL(inet6_lookup_listener);

struct sock *inet6_lookup(struct inet_hashinfo *hashinfo,
			  const struct in6_addr *saddr, const __be16 sport,
			  const struct in6_addr *daddr, const __be16 dport,
			  const int dif)
{
	struct sock *sk;

	local_bh_disable();
	sk = __inet6_lookup(hashinfo, saddr, sport, daddr, ntohs(dport), dif);
	local_bh_enable();

	return sk;
}

EXPORT_SYMBOL_GPL(inet6_lookup);

static int __inet6_check_established(struct inet_timewait_death_row *death_row,
				     struct sock *sk, const __u16 lport,
				     struct inet_timewait_sock **twp)
{
	struct inet_hashinfo *hinfo = death_row->hashinfo;
	struct inet_sock *inet = inet_sk(sk);
	const struct ipv6_pinfo *np = inet6_sk(sk);
	const struct in6_addr *daddr = &np->rcv_saddr;
	const struct in6_addr *saddr = &np->daddr;
	const int dif = sk->sk_bound_dev_if;
	const __portpair ports = INET_COMBINED_PORTS(inet->dport, lport);
	const unsigned int hash = inet6_ehashfn(daddr, lport, saddr,
						inet->dport);
	struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
	rwlock_t *lock = inet_ehash_lockp(hinfo, hash);
	struct sock *sk2;
	const struct hlist_node *node;
	struct inet_timewait_sock *tw;

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

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

		if (INET6_TW_MATCH(sk2, hash, 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 (INET6_MATCH(sk2, hash, 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);
	BUG_TRAP(sk_unhashed(sk));
	__sk_add_node(sk, &head->chain);
	sk->sk_hash = hash;
	sock_prot_inuse_add(sk->sk_prot, 1);
	write_unlock(lock);

	if (twp != NULL) {
		*twp = tw;
		NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
	} else if (tw != NULL) {
		/* 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(lock);
	return -EADDRNOTAVAIL;
}

static inline u32 inet6_sk_port_offset(const struct sock *sk)
{
	const struct inet_sock *inet = inet_sk(sk);
	const struct ipv6_pinfo *np = inet6_sk(sk);
	return secure_ipv6_port_ephemeral(np->rcv_saddr.s6_addr32,
					  np->daddr.s6_addr32,
					  inet->dport);
}

int inet6_hash_connect(struct inet_timewait_death_row *death_row,
		       struct sock *sk)
{
	return __inet_hash_connect(death_row, sk,
			__inet6_check_established, __inet6_hash);
}

EXPORT_SYMBOL_GPL(inet6_hash_connect);
Commit	Line	Data
5324a040 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 INET6 transport hashtables
	7	*
d8313f5c ACM	8	* Authors: Lotsa people, from code originally in tcp, generalised here
d8313f5c ACM	9	* by Arnaldo Carvalho de Melo <acme@mandriva.com>
5324a040 ACM	10	*
	11	* This program is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU General Public License
	13	* as published by the Free Software Foundation; either version
	14	* 2 of the License, or (at your option) any later version.
	15	*/
	16
5324a040	17	#include <linux/module.h>
d8313f5c	18	#include <linux/random.h>
5324a040 ACM	19
	20	#include <net/inet_connection_sock.h>
	21	#include <net/inet_hashtables.h>
	22	#include <net/inet6_hashtables.h>
d8313f5c	23	#include <net/ip.h>
5324a040	24
b1a7ffcb DV	25	void __inet6_hash(struct inet_hashinfo *hashinfo,
	26	struct sock *sk)
	27	{
	28	struct hlist_head *list;
	29	rwlock_t *lock;
	30
	31	BUG_TRAP(sk_unhashed(sk));
	32
	33	if (sk->sk_state == TCP_LISTEN) {
	34	list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
	35	lock = &hashinfo->lhash_lock;
	36	inet_listen_wlock(hashinfo);
	37	} else {
	38	unsigned int hash;
	39	sk->sk_hash = hash = inet6_sk_ehashfn(sk);
230140cf ED	40	list = &inet_ehash_bucket(hashinfo, hash)->chain;
230140cf ED	41	lock = inet_ehash_lockp(hashinfo, hash);
b1a7ffcb DV	42	write_lock(lock);
	43	}
	44
	45	__sk_add_node(sk, list);
65f76517	46	sock_prot_inuse_add(sk->sk_prot, 1);
b1a7ffcb DV	47	write_unlock(lock);
	48	}
	49	EXPORT_SYMBOL(__inet6_hash);
	50
	51	/*
	52	* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
	53	* we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
	54	*
	55	* The sockhash lock must be held as a reader here.
	56	*/
	57	struct sock __inet6_lookup_established(struct inet_hashinfo hashinfo,
	58	const struct in6_addr *saddr,
d2ecd9cc	59	const __be16 sport,
b1a7ffcb DV	60	const struct in6_addr *daddr,
	61	const u16 hnum,
	62	const int dif)
	63	{
	64	struct sock *sk;
	65	const struct hlist_node *node;
4f765d84	66	const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
b1a7ffcb DV	67	/* Optimize here for direct hit, only listening connections can
	68	* have wildcards anyways.
	69	*/
	70	unsigned int hash = inet6_ehashfn(daddr, hnum, saddr, sport);
	71	struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash);
230140cf	72	rwlock_t *lock = inet_ehash_lockp(hashinfo, hash);
b1a7ffcb DV	73
b1a7ffcb DV	74	prefetch(head->chain.first);
230140cf	75	read_lock(lock);
b1a7ffcb DV	76	sk_for_each(sk, node, &head->chain) {
	77	/* For IPV6 do the cheaper port and family tests first. */
	78	if (INET6_MATCH(sk, hash, saddr, daddr, ports, dif))
	79	goto hit; /* You sunk my battleship! */
	80	}
	81	/* Must check for a TIME_WAIT'er before going to listener hash. */
dbca9b27	82	sk_for_each(sk, node, &head->twchain) {
535174ef PE	83	if (INET6_TW_MATCH(sk, hash, saddr, daddr, ports, dif))
535174ef PE	84	goto hit;
b1a7ffcb	85	}
230140cf	86	read_unlock(lock);
b1a7ffcb DV	87	return NULL;
	88
	89	hit:
	90	sock_hold(sk);
230140cf	91	read_unlock(lock);
b1a7ffcb DV	92	return sk;
	93	}
	94	EXPORT_SYMBOL(__inet6_lookup_established);
	95
5324a040 ACM	96	struct sock inet6_lookup_listener(struct inet_hashinfo hashinfo,
	97	const struct in6_addr *daddr,
	98	const unsigned short hnum, const int dif)
	99	{
	100	struct sock *sk;
	101	const struct hlist_node *node;
	102	struct sock *result = NULL;
	103	int score, hiscore = 0;
	104
	105	read_lock(&hashinfo->lhash_lock);
	106	sk_for_each(sk, node, &hashinfo->listening_hash[inet_lhashfn(hnum)]) {
	107	if (inet_sk(sk)->num == hnum && sk->sk_family == PF_INET6) {
	108	const struct ipv6_pinfo *np = inet6_sk(sk);
1ab1457c	109
5324a040 ACM	110	score = 1;
	111	if (!ipv6_addr_any(&np->rcv_saddr)) {
	112	if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
	113	continue;
	114	score++;
	115	}
	116	if (sk->sk_bound_dev_if) {
	117	if (sk->sk_bound_dev_if != dif)
	118	continue;
	119	score++;
	120	}
	121	if (score == 3) {
	122	result = sk;
	123	break;
	124	}
	125	if (score > hiscore) {
	126	hiscore = score;
	127	result = sk;
	128	}
	129	}
	130	}
	131	if (result)
	132	sock_hold(result);
	133	read_unlock(&hashinfo->lhash_lock);
	134	return result;
	135	}
	136
	137	EXPORT_SYMBOL_GPL(inet6_lookup_listener);
	138
	139	struct sock inet6_lookup(struct inet_hashinfo hashinfo,
d2ecd9cc AV	140	const struct in6_addr *saddr, const __be16 sport,
d2ecd9cc AV	141	const struct in6_addr *daddr, const __be16 dport,
5324a040 ACM	142	const int dif)
	143	{
	144	struct sock *sk;
	145
	146	local_bh_disable();
	147	sk = __inet6_lookup(hashinfo, saddr, sport, daddr, ntohs(dport), dif);
	148	local_bh_enable();
	149
	150	return sk;
	151	}
	152
	153	EXPORT_SYMBOL_GPL(inet6_lookup);
d8313f5c ACM	154
	155	static int __inet6_check_established(struct inet_timewait_death_row *death_row,
	156	struct sock *sk, const __u16 lport,
	157	struct inet_timewait_sock **twp)
	158	{
	159	struct inet_hashinfo *hinfo = death_row->hashinfo;
3759fa9c	160	struct inet_sock *inet = inet_sk(sk);
d8313f5c ACM	161	const struct ipv6_pinfo *np = inet6_sk(sk);
	162	const struct in6_addr *daddr = &np->rcv_saddr;
	163	const struct in6_addr *saddr = &np->daddr;
	164	const int dif = sk->sk_bound_dev_if;
4f765d84	165	const __portpair ports = INET_COMBINED_PORTS(inet->dport, lport);
6e1d9d04	166	const unsigned int hash = inet6_ehashfn(daddr, lport, saddr,
d8313f5c ACM	167	inet->dport);
d8313f5c ACM	168	struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
230140cf	169	rwlock_t *lock = inet_ehash_lockp(hinfo, hash);
d8313f5c ACM	170	struct sock *sk2;
	171	const struct hlist_node *node;
	172	struct inet_timewait_sock *tw;
	173
	174	prefetch(head->chain.first);
230140cf	175	write_lock(lock);
d8313f5c ACM	176
d8313f5c ACM	177	/* Check TIME-WAIT sockets first. */
dbca9b27	178	sk_for_each(sk2, node, &head->twchain) {
d8313f5c ACM	179	tw = inet_twsk(sk2);
d8313f5c ACM	180
535174ef	181	if (INET6_TW_MATCH(sk2, hash, saddr, daddr, ports, dif)) {
d8313f5c ACM	182	if (twsk_unique(sk, sk2, twp))
	183	goto unique;
	184	else
	185	goto not_unique;
	186	}
	187	}
	188	tw = NULL;
	189
	190	/* And established part... */
	191	sk_for_each(sk2, node, &head->chain) {
	192	if (INET6_MATCH(sk2, hash, saddr, daddr, ports, dif))
	193	goto not_unique;
	194	}
	195
	196	unique:
3759fa9c HX	197	/* Must record num and sport now. Otherwise we will see
	198	* in hash table socket with a funny identity. */
	199	inet->num = lport;
	200	inet->sport = htons(lport);
d8313f5c ACM	201	BUG_TRAP(sk_unhashed(sk));
	202	__sk_add_node(sk, &head->chain);
	203	sk->sk_hash = hash;
65f76517	204	sock_prot_inuse_add(sk->sk_prot, 1);
230140cf	205	write_unlock(lock);
d8313f5c ACM	206
	207	if (twp != NULL) {
	208	*twp = tw;
	209	NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
	210	} else if (tw != NULL) {
	211	/* Silly. Should hash-dance instead... */
	212	inet_twsk_deschedule(tw, death_row);
	213	NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
	214
	215	inet_twsk_put(tw);
	216	}
	217	return 0;
	218
	219	not_unique:
230140cf	220	write_unlock(lock);
d8313f5c ACM	221	return -EADDRNOTAVAIL;
	222	}
	223
	224	static inline u32 inet6_sk_port_offset(const struct sock *sk)
	225	{
	226	const struct inet_sock *inet = inet_sk(sk);
	227	const struct ipv6_pinfo *np = inet6_sk(sk);
	228	return secure_ipv6_port_ephemeral(np->rcv_saddr.s6_addr32,
	229	np->daddr.s6_addr32,
	230	inet->dport);
	231	}
	232
	233	int inet6_hash_connect(struct inet_timewait_death_row *death_row,
	234	struct sock *sk)
	235	{
5ee31fc1 PE	236	return __inet_hash_connect(death_row, sk,
5ee31fc1 PE	237	__inet6_check_established, __inet6_hash);
d8313f5c ACM	238	}
	239
	240	EXPORT_SYMBOL_GPL(inet6_hash_connect);