From f96ef988cc603487c03a6de07807b06cbe641829 Mon Sep 17 00:00:00 2001 From: Michal Kubecek Date: Tue, 28 May 2013 08:26:49 +0200 Subject: [PATCH] ipv4: fix redirect handling for TCP packets Unlike ipv4_redirect() and ipv4_sk_redirect(), ip_do_redirect() doesn't call __build_flow_key() directly but via ip_rt_build_flow_key() wrapper. This leads to __build_flow_key() getting pointer to IPv4 header of the ICMP redirect packet rather than pointer to the embedded IPv4 header of the packet initiating the redirect. As a result, handling of ICMP redirects initiated by TCP packets is broken. Issue was introduced by 4895c771c ("ipv4: Add FIB nexthop exceptions.") Signed-off-by: Michal Kubecek Signed-off-by: David S. Miller --- net/ipv4/route.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 550781a..d35bbf0 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -737,10 +737,15 @@ static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buf { struct rtable *rt; struct flowi4 fl4; + const struct iphdr *iph = (const struct iphdr *) skb->data; + int oif = skb->dev->ifindex; + u8 tos = RT_TOS(iph->tos); + u8 prot = iph->protocol; + u32 mark = skb->mark; rt = (struct rtable *) dst; - ip_rt_build_flow_key(&fl4, sk, skb); + __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0); __ip_do_redirect(rt, skb, &fl4, true); } -- 2.7.4