[NETFILTER]: nf_conntrack: Fix TCP/UDP HW checksum handling for IPv6 …

…packet If skb->ip_summed is CHECKSUM_HW here, skb->csum includes checksum of actual IPv6 header and extension headers. Then such excess checksum must be subtruct when nf_conntrack calculates TCP/UDP checksum with pseudo IPv6 header. Spotted by Ben Skeggs. Signed-off-by: Yasuyuki Kozakai <[email protected]> Signed-off-by: Patrick McHardy <[email protected]> Signed-off-by: David S. Miller <[email protected]>
josf · Feb 15, 2006 · 7c6de05 · 7c6de05
1 parent 763ecff
commit 7c6de05
Show file tree

Hide file tree

Showing 2 changed files with 6 additions and 2 deletions.
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -864,7 +864,9 @@ static int csum6(const struct sk_buff *skb, unsigned int dataoff)
 {
 	return csum_ipv6_magic(&skb->nh.ipv6h->saddr, &skb->nh.ipv6h->daddr,
 			       skb->len - dataoff, IPPROTO_TCP,
-			       skb->ip_summed == CHECKSUM_HW ? skb->csum
+			       skb->ip_summed == CHECKSUM_HW
+			       ? csum_sub(skb->csum,
+					  skb_checksum(skb, 0, dataoff, 0))
 			       : skb_checksum(skb, dataoff, skb->len - dataoff,
 					      0));
 }

diff --git a/net/netfilter/nf_conntrack_proto_udp.c b/net/netfilter/nf_conntrack_proto_udp.c
@@ -161,7 +161,9 @@ static int csum6(const struct sk_buff *skb, unsigned int dataoff)
 {
 	return csum_ipv6_magic(&skb->nh.ipv6h->saddr, &skb->nh.ipv6h->daddr,
 			       skb->len - dataoff, IPPROTO_UDP,
-			       skb->ip_summed == CHECKSUM_HW ? skb->csum
+			       skb->ip_summed == CHECKSUM_HW
+			       ? csum_sub(skb->csum,
+					  skb_checksum(skb, 0, dataoff, 0))
 			       : skb_checksum(skb, dataoff, skb->len - dataoff,
 					      0));
 }