[PATCH/RFC 04/13] Don't do the UDP socket lookup if we already have one attached
From: KOVACS Krisztian <hidden>
Date: 2007-03-05 15:45:32
Subsystem:
networking [general], the rest, user datagram protocol (udp) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Willem de Bruijn
UDP input code path looks up the UDP socket hash tables to find a socket matching the incoming packet. However, as iptable_tproxy does socket lookups early the skb may already have the appropriate reference attached, in that case we steal that reference instead of doing the lookup. Signed-off-by: KOVACS Krisztian <redacted> --- net/ipv4/udp.c | 11 +++++++++-- 1 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ce6c460..1d15edc 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c@@ -1226,8 +1226,15 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[], if(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable); - sk = __udp4_lib_lookup(saddr, uh->source, daddr, uh->dest, - skb->dev->ifindex, udptable ); + if (skb->sk) { + /* steal reference */ + sk = skb->sk; + skb->destructor = NULL; + skb->sk = NULL; + } else { + sk = __udp4_lib_lookup(saddr, uh->source, daddr, uh->dest, + skb->dev->ifindex, udptable ); + } if (sk != NULL) { int ret = udp_queue_rcv_skb(sk, skb);