CC [M]  net/ipv4/netfilter/ip_conntrack_proto_gre.o
          net/ipv4/netfilter/ip_conntrack_proto_gre.c: In function 'gre_packet':
          net/ipv4/netfilter/ip_conntrack_proto_gre.c:283: warning:
           passing argument 3 of 'ip_ct_refresh_acct' discards qualifiers from pointer target type
          net/ipv4/netfilter/ip_conntrack_proto_gre.c:288: warning:
           passing argument 3 of 'ip_ct_refresh_acct' discards qualifiers from pointer target type
          net/ipv4/netfilter/ip_conntrack_proto_gre.c: At top level:
          net/ipv4/netfilter/ip_conntrack_proto_gre.c:329: warning:
           initialization from incompatible pointer type

Index: linux-2.6.11/net/ipv4/netfilter/ip_conntrack_proto_gre.c
===================================================================
--- linux-2.6.11/net/ipv4/netfilter/ip_conntrack_proto_gre.c	(revision 4208)
+++ linux-2.6.11/net/ipv4/netfilter/ip_conntrack_proto_gre.c	(working copy)
@@ -273,7 +273,7 @@
 
 /* Returns verdict for packet, and may modify conntrack */
 static int gre_packet(struct ip_conntrack *ct,
-		      const struct sk_buff *skb,
+		      struct sk_buff *skb,
 		      enum ip_conntrack_info conntrackinfo)
 {
 	/* If we've seen traffic both ways, this is a GRE connection.