This is a note to let you know that I've just added the patch titled
ipv6: ip6_append_data_mtu do not handle the mtu of the second fragment properly
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ipv6-ip6_append_data_mtu-do-not-handle-the-mtu-of-the-second-fragment-properly.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Fri Apr 11 08:46:36 PDT 2014
From: lucien <lucien.xin@xxxxxxxxx>
Date: Mon, 17 Mar 2014 12:51:01 +0800
Subject: ipv6: ip6_append_data_mtu do not handle the mtu of the second fragment properly
From: lucien <lucien.xin@xxxxxxxxx>
[ Upstream commit e367c2d03dba4c9bcafad24688fadb79dd95b218 ]
In ip6_append_data_mtu(), when the xfrm mode is not tunnel(such as
transport),the ipsec header need to be added in the first fragment, so the mtu
will decrease to reserve space for it, then the second fragment come, the mtu
should be turn back, as the commit 0c1833797a5a6ec23ea9261d979aa18078720b74
said. however, in the commit a493e60ac4bbe2e977e7129d6d8cbb0dd236be, it use
*mtu = min(*mtu, ...) to change the mtu, which lead to the new mtu is alway
equal with the first fragment's. and cannot turn back.
when I test through ping6 -c1 -s5000 $ip (mtu=1280):
...frag (0|1232) ESP(spi=0x00002000,seq=0xb), length 1232
...frag (1232|1216)
...frag (2448|1216)
...frag (3664|1216)
...frag (4880|164)
which should be:
...frag (0|1232) ESP(spi=0x00001000,seq=0x1), length 1232
...frag (1232|1232)
...frag (2464|1232)
...frag (3696|1232)
...frag (4928|116)
so delete the min() when change back the mtu.
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Fixes: 75a493e60ac4bb ("ipv6: ip6_append_data_mtu did not care about pmtudisc and frag_size")
Acked-by: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/ip6_output.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1108,21 +1108,19 @@ static void ip6_append_data_mtu(unsigned
unsigned int fragheaderlen,
struct sk_buff *skb,
struct rt6_info *rt,
- bool pmtuprobe)
+ unsigned int orig_mtu)
{
if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
if (skb == NULL) {
/* first fragment, reserve header_len */
- *mtu = *mtu - rt->dst.header_len;
+ *mtu = orig_mtu - rt->dst.header_len;
} else {
/*
* this fragment is not first, the headers
* space is regarded as data space.
*/
- *mtu = min(*mtu, pmtuprobe ?
- rt->dst.dev->mtu :
- dst_mtu(rt->dst.path));
+ *mtu = orig_mtu;
}
*maxfraglen = ((*mtu - fragheaderlen) & ~7)
+ fragheaderlen - sizeof(struct frag_hdr);
@@ -1139,7 +1137,7 @@ int ip6_append_data(struct sock *sk, int
struct ipv6_pinfo *np = inet6_sk(sk);
struct inet_cork *cork;
struct sk_buff *skb, *skb_prev = NULL;
- unsigned int maxfraglen, fragheaderlen, mtu;
+ unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu;
int exthdrlen;
int dst_exthdrlen;
int hh_len;
@@ -1221,6 +1219,7 @@ int ip6_append_data(struct sock *sk, int
dst_exthdrlen = 0;
mtu = cork->fragsize;
}
+ orig_mtu = mtu;
hh_len = LL_RESERVED_SPACE(rt->dst.dev);
@@ -1300,8 +1299,7 @@ alloc_new_skb:
if (skb == NULL || skb_prev == NULL)
ip6_append_data_mtu(&mtu, &maxfraglen,
fragheaderlen, skb, rt,
- np->pmtudisc ==
- IPV6_PMTUDISC_PROBE);
+ orig_mtu);
skb_prev = skb;
Patches currently in stable-queue which might be from lucien.xin@xxxxxxxxx are
queue-3.10/ipv6-ip6_append_data_mtu-do-not-handle-the-mtu-of-the-second-fragment-properly.patch
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