[UDP6]: Restore sk_filter optimisation

This reverts the changeset

    [IPV6]: UDPv6 checksum.

    We always need to check UDPv6 checksum because it is mandatory.

The sk_filter optimisation has nothing to do whether we verify the
checksum.  It simply postpones it to the point when the user calls
recv or poll.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index f590db57a7c9..3413fc22ce4a 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -279,8 +279,10 @@ int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
                 }
         }
 
-        if (udp_lib_checksum_complete(skb))
-                goto drop;
+        if (sk->sk_filter) {
+                if (udp_lib_checksum_complete(skb))
+                        goto drop;
+        }
 
         if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
                 /* Note that an ENOMEM error is charged twice */