net/ipv6/inet6_hashtables.c - arm/linux - Git at Google

 /*
  * 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 sock *sk)
 {
 	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
 	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 net *net,
 					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, net, 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, net, 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 net *net,
 		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 (sock_net(sk) == net && 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 net *net, 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(net, 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;
 	struct net *net = sock_net(sk);

 	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, net, 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, net, 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_sk_port_offset(sk),
 			__inet6_check_established, __inet6_hash);
 }

 EXPORT_SYMBOL_GPL(inet6_hash_connect);
	/*
	* 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 sock *sk)
	{
	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
	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 net net,
	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, net, 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, net, 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 net net,
	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 (sock_net(sk) == net && 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 net net, 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(net, 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;
	struct net *net = sock_net(sk);

	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, net, 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, net, 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_sk_port_offset(sk),
	__inet6_check_established, __inet6_hash);
	}

	EXPORT_SYMBOL_GPL(inet6_hash_connect);