[patch 16/16] netfilter: restore lost ifdef guarding defragexception

From: Greg KH
Date: Fri Nov 07 2008 - 18:36:55 EST


2.6.25-stable review patch. If anyone has any objections, please let us know.

------------------

From: Patrick McHardy <kaber@xxxxxxxxx>

netfilter: restore lost #ifdef guarding defrag exception

Upstream commit 38f7ac3eb:

Nir Tzachar <nir.tzachar@xxxxxxxxx> reported a warning when sending
fragments over loopback with NAT:

[ 6658.338121] WARNING: at net/ipv4/netfilter/nf_nat_standalone.c:89 nf_nat_fn+0x33/0x155()

The reason is that defragmentation is skipped for already tracked connections.
This is wrong in combination with NAT and ip_conntrack actually had some ifdefs
to avoid this behaviour when NAT is compiled in.

The entire "optimization" may seem a bit silly, for now simply restoring the
lost #ifdef is the easiest solution until we can come up with something better.

Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c | 2 ++
1 file changed, 2 insertions(+)

--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -138,10 +138,12 @@ static unsigned int ipv4_conntrack_defra
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
+#if !defined(CONFIG_NF_NAT) && !defined(CONFIG_NF_NAT_MODULE)
/* Previously seen (loopback)? Ignore. Do this before
fragment check. */
if (skb->nfct)
return NF_ACCEPT;
+#endif

/* Gather fragments. */
if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {

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