Commit a8fdf2b3 authored Sep 03, 2009 by Cosmin Ratiu Committed by David S. Miller Sep 03, 2009

ipv6: Fix tcp_v6_send_response(): it didn't set skb transport header



Here is a patch which fixes an issue observed when using TCP over IPv6
and AH from IPsec.

When a connection gets closed the 4-way method and the last ACK from
the server gets dropped, the subsequent FINs from the client do not
get ACKed because tcp_v6_send_response does not set the transport
header pointer. This causes ah6_output to try to allocate a lot of
memory, which typically fails, so the ACKs never make it out of the
stack.

I have reproduced the problem on kernel 2.6.7, but after looking at
the latest kernel it seems the problem is still there.

Signed-off-by: Cosmin Ratiu <cratiu@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 6fdfa970

net/ipv6/tcp_ipv6.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -1003,6 +1003,7 @@ static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
		skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);

		t1 = (struct tcphdr *) skb_push(buff, tot_len);
		skb_reset_transport_header(skb);

		/* Swap the send and the receive. */
		memset(t1, 0, sizeof(*t1));

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