From e3be8ba79294df5de96692411e122506b40c5aa4 Mon Sep 17 00:00:00 2001
From: Keir Fraser <Keir.Fraser@xl.cam.ac.uk>
Date: Tue, 21 Jun 2005 14:03:23 -0700
Subject: [PATCH] [NETFILTER]: Avoid unncessary checksum validation in UDP
 connection tracking

Signed-off-by: Keir Fraser <Keir.Fraser@xl.cam.ac.uk>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/netfilter/ip_conntrack_proto_udp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/ipv4/netfilter/ip_conntrack_proto_udp.c b/net/ipv4/netfilter/ip_conntrack_proto_udp.c
index 5bc28a224623..8c1eaba098d4 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_udp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_udp.c
@@ -120,6 +120,7 @@ static int udp_error(struct sk_buff *skb, enum ip_conntrack_info *ctinfo,
 	 * and moreover root might send raw packets.
 	 * FIXME: Source route IP option packets --RR */
 	if (hooknum == NF_IP_PRE_ROUTING
+	    && skb->ip_summed != CHECKSUM_UNNECESSARY
 	    && csum_tcpudp_magic(iph->saddr, iph->daddr, udplen, IPPROTO_UDP,
 			         skb->ip_summed == CHECKSUM_HW ? skb->csum
 			      	 : skb_checksum(skb, iph->ihl*4, udplen, 0))) {
-- 
2.30.2