inet_hashtables: Add inet_lookup_skb helpers

To be able to use the cached socket reference in the skb during input
processing we add a new set of lookup functions that receive the skb on
their argument list.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/inet6_hashtables.h

@@ -91,6 +91,17 @@ static inline struct sock *__inet6_lookup(struct net *net,
 	return inet6_lookup_listener(net, hashinfo, daddr, hnum, dif);
 }
 
+static inline struct sock *__inet6_lookup_skb(struct inet_hashinfo *hashinfo,
+					      struct sk_buff *skb,
+					      const __be16 sport,
+					      const __be16 dport)
+{
+	return __inet6_lookup(dev_net(skb->dst->dev), hashinfo,
+			      &ipv6_hdr(skb)->saddr, sport,
+			      &ipv6_hdr(skb)->daddr, ntohs(dport),
+			      inet6_iif(skb));
+}
+
 extern 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,

include/net/inet_hashtables.h

@@ -16,6 +16,7 @@
 
 
 #include <linux/interrupt.h>
+#include <linux/ip.h>
 #include <linux/ipv6.h>
 #include <linux/list.h>
 #include <linux/slab.h>
@@ -28,6 +29,7 @@
 #include <net/inet_connection_sock.h>
 #include <net/inet_sock.h>
 #include <net/sock.h>
+#include <net/route.h>
 #include <net/tcp_states.h>
 #include <net/netns/hash.h>
 
@@ -371,6 +373,18 @@ static inline struct sock *inet_lookup(struct net *net,
 	return sk;
 }
 
+static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo,
+					     struct sk_buff *skb,
+					     const __be16 sport,
+					     const __be16 dport)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+
+	return __inet_lookup(dev_net(skb->dst->dev), hashinfo,
+			     iph->saddr, sport,
+			     iph->daddr, dport, inet_iif(skb));
+}
+
 extern int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 		struct sock *sk, u32 port_offset,
 		int (*check_established)(struct inet_timewait_death_row *,

net/dccp/ipv4.c

@@ -811,9 +811,8 @@ static int dccp_v4_rcv(struct sk_buff *skb)
 
 	/* Step 2:
 	 *	Look up flow ID in table and get corresponding socket */
-	sk = __inet_lookup(dev_net(skb->dst->dev), &dccp_hashinfo,
-			   iph->saddr, dh->dccph_sport,
-			   iph->daddr, dh->dccph_dport, inet_iif(skb));
+	sk = __inet_lookup_skb(&dccp_hashinfo, skb,
+			       dh->dccph_sport, dh->dccph_dport);
 	/*
 	 * Step 2:
 	 *	If no socket ...

net/dccp/ipv6.c

@@ -805,10 +805,8 @@ static int dccp_v6_rcv(struct sk_buff *skb)
 
 	/* Step 2:
 	 *	Look up flow ID in table and get corresponding socket */
-	sk = __inet6_lookup(dev_net(skb->dst->dev), &dccp_hashinfo,
-			    &ipv6_hdr(skb)->saddr, dh->dccph_sport,
-			    &ipv6_hdr(skb)->daddr, ntohs(dh->dccph_dport),
-			    inet6_iif(skb));
+	sk = __inet6_lookup_skb(&dccp_hashinfo, skb,
+			        dh->dccph_sport, dh->dccph_dport);
 	/*
 	 * Step 2:
 	 *	If no socket ...

net/ipv4/tcp_ipv4.c

@@ -1577,8 +1577,7 @@ int tcp_v4_rcv(struct sk_buff *skb)
 	TCP_SKB_CB(skb)->flags	 = iph->tos;
 	TCP_SKB_CB(skb)->sacked	 = 0;
 
-	sk = __inet_lookup(net, &tcp_hashinfo, iph->saddr,
-			th->source, iph->daddr, th->dest, inet_iif(skb));
+	sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
 	if (!sk)
 		goto no_tcp_socket;
 

net/ipv6/tcp_ipv6.c

@@ -1681,11 +1681,7 @@ static int tcp_v6_rcv(struct sk_buff *skb)
 	TCP_SKB_CB(skb)->flags = ipv6_get_dsfield(ipv6_hdr(skb));
 	TCP_SKB_CB(skb)->sacked = 0;
 
-	sk = __inet6_lookup(net, &tcp_hashinfo,
-			&ipv6_hdr(skb)->saddr, th->source,
-			&ipv6_hdr(skb)->daddr, ntohs(th->dest),
-			inet6_iif(skb));
-
+	sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
 	if (!sk)
 		goto no_tcp_socket;