[NETFILTER]: nf_nat_proto_gre: do not modify/corrupt GREv0 packets through NAT

While porting some changes of the 2.6.21-rc7 pptp/proto_gre conntrack
and nat modules to a 2.4.32 kernel I noticed that the gre_key function
returns a wrong pointer to the GRE key of a version 0 packet thus
corrupting the packet payload.

The intended behaviour for GREv0 packets is to act like
nf_conntrack_proto_generic/nf_nat_proto_unknown so I have ripped the
offending functions (not used anymore) and modified the
nf_nat_proto_gre modules to not touch version 0 (non PPTP) packets.

Signed-off-by: Jorge Boncompte <jorge@dti2.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 18 deletions

diff --git a/include/linux/netfilter/nf_conntrack_proto_gre.h b/include/linux/netfilter/nf_conntrack_proto_gre.h
index 4e6bbce04ff8..535e4219d2bb 100644
--- a/include/linux/netfilter/nf_conntrack_proto_gre.h
+++ b/include/linux/netfilter/nf_conntrack_proto_gre.h
@@ -87,24 +87,6 @@ int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
 /* delete keymap entries */
 void nf_ct_gre_keymap_destroy(struct nf_conn *ct);
 
-/* get pointer to gre key, if present */
-static inline __be32 *gre_key(struct gre_hdr *greh)
-{
-        if (!greh->key)
-                return NULL;
-        if (greh->csum || greh->routing)
-                return (__be32 *)(greh+sizeof(*greh)+4);
-        return (__be32 *)(greh+sizeof(*greh));
-}
-
-/* get pointer ot gre csum, if present */
-static inline __sum16 *gre_csum(struct gre_hdr *greh)
-{
-        if (!greh->csum)
-                return NULL;
-        return (__sum16 *)(greh+sizeof(*greh));
-}
-
 extern void nf_ct_gre_keymap_flush(void);
 extern void nf_nat_need_gre(void);