[3.16.y-ckt stable] Patch "ipvs: correct initial offset of Call-ID header search in SIP persistence engine" has been added to the 3.16.y-ckt tree

[Luis Henriques]

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

    ipvs: correct initial offset of Call-ID header search in SIP persistence engine

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt27.

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

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

---8<------------------------------------------------------------

>From 9869b9f06acb6c2523ce473b96eaa22e0ac24215 Mon Sep 17 00:00:00 2001
From: Marco Angaroni <marcoangaroni at gmail.com>
Date: Sat, 5 Mar 2016 12:10:02 +0100
Subject: ipvs: correct initial offset of Call-ID header search in SIP
 persistence engine

commit 7617a24f83b5d67f4dab1844956be1cebc44aec8 upstream.

The IPVS SIP persistence engine is not able to parse the SIP header
"Call-ID" when such header is inserted in the first positions of
the SIP message.

When IPVS is configured with "--pe sip" option, like for example:
ipvsadm -A -u 1.2.3.4:5060 -s rr --pe sip -p 120 -o
some particular messages (see below for details) do not create entries
in the connection template table, which can be listed with:
ipvsadm -Lcn --persistent-conn

Problematic SIP messages are SIP responses having "Call-ID" header
positioned just after message first line:
SIP/2.0 200 OK
[Call-ID header here]
[rest of the headers]

When "Call-ID" header is positioned down (after a few other headers)
it is correctly recognized.

This is due to the data offset used in get_callid function call inside
ip_vs_pe_sip.c file: since dptr already points to the start of the
SIP message, the value of dataoff should be initially 0.
Otherwise the header is searched starting from some bytes after the
first character of the SIP message.

Fixes: 758ff0338722 ("IPVS: sip persistence engine")
Signed-off-by: Marco Angaroni <marcoangaroni at gmail.com>
Acked-by: Julian Anastasov <ja at ssi.bg>
Signed-off-by: Simon Horman <horms at verge.net.au>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/netfilter/ipvs/ip_vs_pe_sip.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/ipvs/ip_vs_pe_sip.c b/net/netfilter/ipvs/ip_vs_pe_sip.c
index bed5f7042529..bb318e4623a3 100644
--- a/net/netfilter/ipvs/ip_vs_pe_sip.c
+++ b/net/netfilter/ipvs/ip_vs_pe_sip.c
@@ -88,7 +88,7 @@ ip_vs_sip_fill_param(struct ip_vs_conn_param *p, struct sk_buff *skb)
 	dptr = skb->data + dataoff;
 	datalen = skb->len - dataoff;

-	if (get_callid(dptr, dataoff, datalen, &matchoff, &matchlen))
+	if (get_callid(dptr, 0, datalen, &matchoff, &matchlen))
 		return -EINVAL;

 	/* N.B: pe_data is only set on success,