Subject: [PATCHv2] netfilter: Remove skb_is_nonlinear check from nf_conntrack_sip

From: Jason Gunthorpe <[email-masked]>
Date: Fri, 14 May 2010 12:01:38 -0600

At least the XEN net front driver always produces non linear skbs,
so the SIP module does nothing at all when used with that NIC.

Unconditionally linearize the skb..

Signed-off-by: Jason Gunthorpe <[email-masked]>
---
 net/netfilter/nf_conntrack_sip.c |    9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

Patrick/Jan, thanks.. This is what I wanted to do in the first place,
but I couldn't convince myself it was safe, as no other nf code does
this..

Unfortunately I can no longer test it :(
 
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 4b57216..02d0b59 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -1275,13 +1275,10 @@ static int sip_help(struct sk_buff *skb,
 
 	nf_ct_refresh(ct, skb, sip_timeout * HZ);
 
-	if (!skb_is_nonlinear(skb))
-		dptr = skb->data + dataoff;
-	else {
-		pr_debug("Copy of skbuff not supported yet.\n");
-		return NF_ACCEPT;
-	}
+	if (unlikely(skb_linearize(skb)))
+		return NF_DROP;
 
+	dptr = skb->data + dataoff;
 	datalen = skb->len - dataoff;
 	if (datalen < strlen("SIP/2.0 200"))
 		return NF_ACCEPT;
-- 
1.6.0.4