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Commit 33b62231 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo Committed by David S. Miller
Browse files

[INET]: Generalise tcp_v4_lookup_listener 



[acme@toy net-2.6.14]$ grep built-in /tmp/before /tmp/after
/tmp/before: 282560       13122    9312  304994   4a762 net/ipv4/built-in.o
/tmp/after:  282560       13122    9312  304994   4a762 net/ipv4/built-in.o

Will be used in DCCP, not exporting it right now not to get in Adrian
Bunk's exported-but-not-used-on-modules radar 8)

Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 81849d10

include/net/inet_hashtables.h

+36 −0
Original line number Diff line number Diff line
@@ -16,8 +16,10 @@ 


#include <linux/interrupt.h>

#include <linux/ip.h>

#include <linux/ipv6.h>

#include <linux/list.h>

#include <linux/slab.h>

#include <linux/socket.h>

#include <linux/spinlock.h>

#include <linux/types.h>

#include <linux/wait.h>
@@ -274,4 +276,38 @@ static inline void inet_unhash(struct inet_hashinfo *hashinfo, struct sock *sk) 
	if (sk->sk_state == TCP_LISTEN)

		wake_up(&hashinfo->lhash_wait);

}



extern struct sock *__inet_lookup_listener(const struct hlist_head *head,

					   const u32 daddr,

					   const unsigned short hnum,

					   const int dif);



/* Optimize the common listener case. */

static inline struct sock *inet_lookup_listener(struct inet_hashinfo *hashinfo,

						const u32 daddr,

						const unsigned short hnum,

						const int dif)

{

	struct sock *sk = NULL;

	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(head, daddr, hnum, dif);

	}

	if (sk) {

sherry_cache:

		sock_hold(sk);

	}

	read_unlock(&hashinfo->lhash_lock);

	return sk;

}

#endif /* _INET_HASHTABLES_H */

net/ipv4/inet_hashtables.c

+41 −0
Original line number Diff line number Diff line
@@ -121,3 +121,44 @@ void inet_listen_wlock(struct inet_hashinfo *hashinfo) 
}



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.

 */

struct sock *__inet_lookup_listener(const struct hlist_head *head, const u32 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 __u32 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;

}

net/ipv4/tcp_ipv4.c

+5 −76
Original line number Diff line number Diff line
@@ -238,78 +238,6 @@ void tcp_unhash(struct sock *sk) 
	inet_unhash(&tcp_hashinfo, sk);

}



/* Don't inline this cruft.  Here are some nice properties to

 * exploit here.  The BSD API does not allow a listening TCP

 * 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 *__tcp_v4_lookup_listener(struct hlist_head *head,

					     const u32 daddr,

					     const unsigned short hnum,

					     const int dif)

{

	struct sock *result = NULL, *sk;

	struct hlist_node *node;

	int score, hiscore;



	hiscore=-1;

	sk_for_each(sk, node, head) {

		struct inet_sock *inet = inet_sk(sk);



		if (inet->num == hnum && !ipv6_only_sock(sk)) {

			__u32 rcv_saddr = inet->rcv_saddr;



			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. */

static inline struct sock *tcp_v4_lookup_listener(const u32 daddr,

						  const unsigned short hnum,

						  const int dif)

{

	struct sock *sk = NULL;

	struct hlist_head *head;



	read_lock(&tcp_hashinfo.lhash_lock);

	head = &tcp_hashinfo.listening_hash[inet_lhashfn(hnum)];

	if (!hlist_empty(head)) {

		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 = __tcp_v4_lookup_listener(head, daddr, hnum, dif);

	}

	if (sk) {

sherry_cache:

		sock_hold(sk);

	}

	read_unlock(&tcp_hashinfo.lhash_lock);

	return sk;

}



/* 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

 *
@@ -358,7 +286,7 @@ static inline struct sock *__tcp_v4_lookup(u32 saddr, u16 sport, 
	struct sock *sk = __tcp_v4_lookup_established(saddr, sport,

						      daddr, hnum, dif);



	return sk ? : tcp_v4_lookup_listener(daddr, hnum, dif);

	return sk ? : inet_lookup_listener(&tcp_hashinfo, daddr, hnum, dif);

}



inline struct sock *tcp_v4_lookup(u32 saddr, u16 sport, u32 daddr,
@@ -1641,7 +1569,8 @@ int tcp_v4_rcv(struct sk_buff *skb) 
	switch (tcp_timewait_state_process((struct tcp_tw_bucket *)sk,

					   skb, th, skb->len)) {

	case TCP_TW_SYN: {

		struct sock *sk2 = tcp_v4_lookup_listener(skb->nh.iph->daddr,

		struct sock *sk2 = inet_lookup_listener(&tcp_hashinfo,

							skb->nh.iph->daddr,

							ntohs(th->dest),

							tcp_v4_iif(skb));

		if (sk2) {