inet: Don't lookup the socket if there's a socket attached to the skb

Use the socket cached in the skb if it's present.

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>

5 files changed, 41 insertions, 13 deletions

diff --git a/include/net/inet6_hashtables.h b/include/net/inet6_hashtables.h
index 995efbb031ab..f74665d7bea8 100644
--- a/include/net/inet6_hashtables.h
+++ b/include/net/inet6_hashtables.h
@@ -96,10 +96,14 @@ static inline struct sock *__inet6_lookup_skb(struct inet_hashinfo *hashinfo,
                                               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));
+        struct sock *sk;
+
+        if (unlikely(sk = skb_steal_sock(skb)))
+                return sk;
+        else 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,
diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index 3522bbcd546d..5cc182f9ecae 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -378,11 +378,15 @@ static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo,
                                              const __be16 sport,
                                              const __be16 dport)
 {
+        struct sock *sk;
         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));
+        if (unlikely(sk = skb_steal_sock(skb)))
+                return sk;
+        else
+                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,
diff --git a/include/net/sock.h b/include/net/sock.h
index 75a312d3888a..18f96708f3a6 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1324,6 +1324,18 @@ static inline void sk_change_net(struct sock *sk, struct net *net)
         sock_net_set(sk, hold_net(net));
 }
 
+static inline struct sock *skb_steal_sock(struct sk_buff *skb)
+{
+        if (unlikely(skb->sk)) {
+                struct sock *sk = skb->sk;
+
+                skb->destructor = NULL;
+                skb->sk = NULL;
+                return sk;
+        }
+        return NULL;
+}
+
 extern void sock_enable_timestamp(struct sock *sk);
 extern int sock_get_timestamp(struct sock *, struct timeval __user *);
 extern int sock_get_timestampns(struct sock *, struct timespec __user *);
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index c7a90b546b21..822c9deac83b 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -306,11 +306,15 @@ static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
                                                  __be16 sport, __be16 dport,
                                                  struct hlist_head udptable[])
 {
+        struct sock *sk;
         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);
+        if (unlikely(sk = skb_steal_sock(skb)))
+                return sk;
+        else
+                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,
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index ce26c41d157d..e51da8c092fa 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -111,11 +111,15 @@ static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
                                           __be16 sport, __be16 dport,
                                           struct hlist_head udptable[])
 {
+        struct sock *sk;
         struct ipv6hdr *iph = ipv6_hdr(skb);
 
-        return __udp6_lib_lookup(dev_net(skb->dst->dev), &iph->saddr, sport,
-                                 &iph->daddr, dport, inet6_iif(skb),
-                                 udptable);
+        if (unlikely(sk = skb_steal_sock(skb)))
+                return sk;
+        else
+                return __udp6_lib_lookup(dev_net(skb->dst->dev), &iph->saddr, sport,
+                                         &iph->daddr, dport, inet6_iif(skb),
+                                         udptable);
 }
 
 /*