[PATCH 3.16 015/157] netfilter: bridge: set skb transport_header before entering NF_INET_PRE_ROUTING

[Ben Hutchings]

3.16.72-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Xin Long <lucien.xin@xxxxxxxxx>

commit e166e4fdaced850bee3d5ee12a5740258fb30587 upstream.

Since Commit 21d1196a35f5 ("ipv4: set transport header earlier"),
skb->transport_header has been always set before entering INET
netfilter. This patch is to set skb->transport_header for bridge
before entering INET netfilter by bridge-nf-call-iptables.

It also fixes an issue that sctp_error() couldn't compute a right
csum due to unset skb->transport_header.

Fixes: e6d8b64b34aa ("net: sctp: fix and consolidate SCTP checksumming code")
Reported-by: Li Shuang <shuali@xxxxxxxxxx>
Suggested-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
Acked-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -659,6 +659,8 @@ static unsigned int br_nf_pre_routing_ip
 		return NF_DROP;
 
 	skb->protocol = htons(ETH_P_IPV6);
+	skb->transport_header = skb->network_header + sizeof(struct ipv6hdr);
+
 	NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
 		br_nf_pre_routing_finish_ipv6);
 
@@ -715,6 +717,7 @@ static unsigned int br_nf_pre_routing(co
 		return NF_DROP;
 	store_orig_dstaddr(skb);
 	skb->protocol = htons(ETH_P_IP);
+	skb->transport_header = skb->network_header + ip_hdr(skb)->ihl * 4;
 
 	NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
 		br_nf_pre_routing_finish);