Commit f96ef988 authored May 28, 2013 by Michal Kubecek Committed by David S. Miller May 27, 2013

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

	4895c771 ("ipv4: Add FIB nexthop exceptions.")

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 9a9c56cb

net/ipv4/route.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -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);
		}

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