[3.8.y.z extended stable] Patch "ipv6: reuse ip6_frag_id from ip6_ufo_append_data" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    ipv6: reuse ip6_frag_id from ip6_ufo_append_data

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.21.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 80774c9ca0378ad94b0ebe8c02adc3ffd3889a3c Mon Sep 17 00:00:00 2001
From: Hannes Frederic Sowa <hannes at stressinduktion.org>
Date: Fri, 21 Feb 2014 02:55:35 +0100
Subject: ipv6: reuse ip6_frag_id from ip6_ufo_append_data

[ Upstream commit 916e4cf46d0204806c062c8c6c4d1f633852c5b6 ]

Currently we generate a new fragmentation id on UFO segmentation. It
is pretty hairy to identify the correct net namespace and dst there.
Especially tunnels use IFF_XMIT_DST_RELEASE and thus have no skb_dst
available at all.

This causes unreliable or very predictable ipv6 fragmentation id
generation while segmentation.

Luckily we already have pregenerated the ip6_frag_id in
ip6_ufo_append_data and can use it here.

Signed-off-by: Hannes Frederic Sowa <hannes at stressinduktion.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/ipv6/udp_offload.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index 0c8934a..38bfafd 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -97,7 +97,7 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
 	fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
 	fptr->nexthdr = nexthdr;
 	fptr->reserved = 0;
-	ipv6_select_ident(fptr, (struct rt6_info *)skb_dst(skb));
+	fptr->identification = skb_shinfo(skb)->ip6_frag_id;

 	/* Fragment the skb. ipv6 header and the remaining fields of the
 	 * fragment header are updated in ipv6_gso_segment()
--
1.8.3.2