inet: Add udplib_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: KOVACS Krisztian <hidden@sch.bme.hu>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 2 deletions

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index c83d0ef469c9..c7a90b546b21 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -302,6 +302,17 @@ static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
         return result;
 }
 
+static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
+                                                 __be16 sport, __be16 dport,
+                                                 struct hlist_head udptable[])
+{
+        const struct iphdr *iph = ip_hdr(skb);
+
+        return __udp4_lib_lookup(dev_net(skb->dst->dev), iph->saddr, sport,
+                                 iph->daddr, dport, inet_iif(skb),
+                                 udptable);
+}
+
 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
                              __be32 daddr, __be16 dport, int dif)
 {
@@ -1208,8 +1219,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
                 return __udp4_lib_mcast_deliver(net, skb, uh,
                                 saddr, daddr, udptable);
 
-        sk = __udp4_lib_lookup(net, saddr, uh->source, daddr,
-                        uh->dest, inet_iif(skb), udptable);
+        sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
 
         if (sk != NULL) {
                 int ret = udp_queue_rcv_skb(sk, skb);