[NETNS]: Tcp-v4 sockets per-net lookup.

Add a net argument to inet_lookup and propagate it further
into lookup calls. Plus tune the __inet_check_established.

The dccp and inet_diag, which use that lookup functions
pass the init_net into them.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 9e38b0d..c982ad8 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -218,7 +218,7 @@
 		return;
 	}
 
-	sk = inet_lookup(&dccp_hashinfo, iph->daddr, dh->dccph_dport,
+	sk = inet_lookup(&init_net, &dccp_hashinfo, iph->daddr, dh->dccph_dport,
 			 iph->saddr, dh->dccph_sport, inet_iif(skb));
 	if (sk == NULL) {
 		ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
@@ -436,7 +436,7 @@
 	if (req != NULL)
 		return dccp_check_req(sk, skb, req, prev);
 
-	nsk = inet_lookup_established(&dccp_hashinfo,
+	nsk = inet_lookup_established(&init_net, &dccp_hashinfo,
 				      iph->saddr, dh->dccph_sport,
 				      iph->daddr, dh->dccph_dport,
 				      inet_iif(skb));
@@ -817,7 +817,7 @@
 
 	/* Step 2:
 	 *	Look up flow ID in table and get corresponding socket */
-	sk = __inet_lookup(&dccp_hashinfo,
+	sk = __inet_lookup(&init_net, &dccp_hashinfo,
 			   iph->saddr, dh->dccph_sport,
 			   iph->daddr, dh->dccph_dport, inet_iif(skb));
 	/*
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 4cfb15c..95c9f14 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -268,7 +268,7 @@
 	err = -EINVAL;
 
 	if (req->idiag_family == AF_INET) {
-		sk = inet_lookup(hashinfo, req->id.idiag_dst[0],
+		sk = inet_lookup(&init_net, hashinfo, req->id.idiag_dst[0],
 				 req->id.idiag_dport, req->id.idiag_src[0],
 				 req->id.idiag_sport, req->id.idiag_if);
 	}
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index db1e53a..48d4500 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -127,7 +127,8 @@
  * 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,
+static struct sock *inet_lookup_listener_slow(struct net *net,
+					      const struct hlist_head *head,
 					      const __be32 daddr,
 					      const unsigned short hnum,
 					      const int dif)
@@ -139,7 +140,8 @@
 	sk_for_each(sk, node, head) {
 		const struct inet_sock *inet = inet_sk(sk);
 
-		if (inet->num == hnum && !ipv6_only_sock(sk)) {
+		if (sk->sk_net == net && inet->num == hnum &&
+				!ipv6_only_sock(sk)) {
 			const __be32 rcv_saddr = inet->rcv_saddr;
 			int score = sk->sk_family == PF_INET ? 1 : 0;
 
@@ -165,7 +167,8 @@
 }
 
 /* Optimize the common listener case. */
-struct sock *__inet_lookup_listener(struct inet_hashinfo *hashinfo,
+struct sock *__inet_lookup_listener(struct net *net,
+				    struct inet_hashinfo *hashinfo,
 				    const __be32 daddr, const unsigned short hnum,
 				    const int dif)
 {
@@ -180,9 +183,9 @@
 		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)
+		    !sk->sk_bound_dev_if && sk->sk_net == net)
 			goto sherry_cache;
-		sk = inet_lookup_listener_slow(head, daddr, hnum, dif);
+		sk = inet_lookup_listener_slow(net, head, daddr, hnum, dif);
 	}
 	if (sk) {
 sherry_cache:
@@ -193,7 +196,8 @@
 }
 EXPORT_SYMBOL_GPL(__inet_lookup_listener);
 
-struct sock * __inet_lookup_established(struct inet_hashinfo *hashinfo,
+struct sock * __inet_lookup_established(struct net *net,
+				  struct inet_hashinfo *hashinfo,
 				  const __be32 saddr, const __be16 sport,
 				  const __be32 daddr, const u16 hnum,
 				  const int dif)
@@ -212,13 +216,15 @@
 	prefetch(head->chain.first);
 	read_lock(lock);
 	sk_for_each(sk, node, &head->chain) {
-		if (INET_MATCH(sk, hash, acookie, saddr, daddr, ports, dif))
+		if (INET_MATCH(sk, net, hash, acookie,
+					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 (INET_TW_MATCH(sk, hash, acookie, saddr, daddr, ports, dif))
+		if (INET_TW_MATCH(sk, net, hash, acookie,
+					saddr, daddr, ports, dif))
 			goto hit;
 	}
 	sk = NULL;
@@ -249,6 +255,7 @@
 	struct sock *sk2;
 	const struct hlist_node *node;
 	struct inet_timewait_sock *tw;
+	struct net *net = sk->sk_net;
 
 	prefetch(head->chain.first);
 	write_lock(lock);
@@ -257,7 +264,8 @@
 	sk_for_each(sk2, node, &head->twchain) {
 		tw = inet_twsk(sk2);
 
-		if (INET_TW_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif)) {
+		if (INET_TW_MATCH(sk2, net, hash, acookie,
+					saddr, daddr, ports, dif)) {
 			if (twsk_unique(sk, sk2, twp))
 				goto unique;
 			else
@@ -268,7 +276,8 @@
 
 	/* And established part... */
 	sk_for_each(sk2, node, &head->chain) {
-		if (INET_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif))
+		if (INET_MATCH(sk2, net, hash, acookie,
+					saddr, daddr, ports, dif))
 			goto not_unique;
 	}
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 9aea88b..77c1939 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -369,8 +369,8 @@
 		return;
 	}
 
-	sk = inet_lookup(&tcp_hashinfo, iph->daddr, th->dest, iph->saddr,
-			 th->source, inet_iif(skb));
+	sk = inet_lookup(skb->dev->nd_net, &tcp_hashinfo, iph->daddr, th->dest,
+			iph->saddr, th->source, inet_iif(skb));
 	if (!sk) {
 		ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
 		return;
@@ -1503,8 +1503,8 @@
 	if (req)
 		return tcp_check_req(sk, skb, req, prev);
 
-	nsk = inet_lookup_established(&tcp_hashinfo, iph->saddr, th->source,
-				      iph->daddr, th->dest, inet_iif(skb));
+	nsk = inet_lookup_established(sk->sk_net, &tcp_hashinfo, iph->saddr,
+			th->source, iph->daddr, th->dest, inet_iif(skb));
 
 	if (nsk) {
 		if (nsk->sk_state != TCP_TIME_WAIT) {
@@ -1661,8 +1661,8 @@
 	TCP_SKB_CB(skb)->flags	 = iph->tos;
 	TCP_SKB_CB(skb)->sacked	 = 0;
 
-	sk = __inet_lookup(&tcp_hashinfo, iph->saddr, th->source,
-			   iph->daddr, th->dest, inet_iif(skb));
+	sk = __inet_lookup(skb->dev->nd_net, &tcp_hashinfo, iph->saddr,
+			th->source, iph->daddr, th->dest, inet_iif(skb));
 	if (!sk)
 		goto no_tcp_socket;
 
@@ -1735,7 +1735,8 @@
 	}
 	switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
 	case TCP_TW_SYN: {
-		struct sock *sk2 = inet_lookup_listener(&tcp_hashinfo,
+		struct sock *sk2 = inet_lookup_listener(skb->dev->nd_net,
+							&tcp_hashinfo,
 							iph->daddr, th->dest,
 							inet_iif(skb));
 		if (sk2) {