netfilter: conntrack: remove pkt_to_tuple callback

GRE is now builtin, so we can handle it via direct call and
remove the callback.

Signed-off-by: Florian Westphal <[e-mail]>
Signed-off-by: Pablo Neira Ayuso <[e-mail]>

include/linux/netfilter/nf_conntrack_proto_gre.h

···
 /* delete keymap entries */
 void nf_ct_gre_keymap_destroy(struct nf_conn *ct);
 
+bool gre_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
+		      struct net *net, struct nf_conntrack_tuple *tuple);
 #endif /* __KERNEL__ */
 #endif /* _CONNTRACK_PROTO_GRE_H */

include/net/netfilter/nf_conntrack_l4proto.h

···
 	/* protoinfo nlattr size, closes a hole */
 	u16 nlattr_size;
 
-	/* Try to fill in the third arg: dataoff is offset past network protocol
-           hdr.  Return true if possible. */
-	bool (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int dataoff,
-			     struct net *net, struct nf_conntrack_tuple *tuple);
-
 	/* Invert the per-proto part of the tuple: ie. turn xmit into reply.
 	 * Only used by icmp, most protocols use a generic version.
 	 */

net/netfilter/nf_conntrack_core.c

···
 		return icmpv6_pkt_to_tuple(skb, dataoff, net, tuple);
 	case IPPROTO_ICMP:
 		return icmp_pkt_to_tuple(skb, dataoff, net, tuple);
+#ifdef CONFIG_NF_CT_PROTO_GRE
+	case IPPROTO_GRE:
+		return gre_pkt_to_tuple(skb, dataoff, net, tuple);
+#endif
 	}
-	if (unlikely(l4proto->pkt_to_tuple))
-		return l4proto->pkt_to_tuple(skb, dataoff, net, tuple);
 
 	/* Actually only need first 4 bytes to get ports. */
 	inet_hdr = skb_header_pointer(skb, dataoff, sizeof(_inet_hdr), &_inet_hdr);

net/netfilter/nf_conntrack_proto_generic.c

···
 	}
 }
 
-static bool generic_pkt_to_tuple(const struct sk_buff *skb,
-				 unsigned int dataoff,
-				 struct net *net, struct nf_conntrack_tuple *tuple)
-{
-	tuple->src.u.all = 0;
-	tuple->dst.u.all = 0;
-
-	return true;
-}
-
 /* Returns verdict for packet, or -1 for invalid. */
 static int generic_packet(struct nf_conn *ct,
 			  struct sk_buff *skb,
···
 const struct nf_conntrack_l4proto nf_conntrack_l4proto_generic =
 {
 	.l4proto		= 255,
-	.pkt_to_tuple		= generic_pkt_to_tuple,
 	.packet			= generic_packet,
 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
 	.ctnl_timeout		= {

net/netfilter/nf_conntrack_proto_gre.c

···
 /* PUBLIC CONNTRACK PROTO HELPER FUNCTIONS */
 
 /* gre hdr info to tuple */
-static bool gre_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
-			     struct net *net, struct nf_conntrack_tuple *tuple)
+bool gre_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
+		      struct net *net, struct nf_conntrack_tuple *tuple)
 {
 	const struct pptp_gre_header *pgrehdr;
 	struct pptp_gre_header _pgrehdr;
···
 /* protocol helper struct */
 const struct nf_conntrack_l4proto nf_conntrack_l4proto_gre = {
 	.l4proto	 = IPPROTO_GRE,
-	.pkt_to_tuple	 = gre_pkt_to_tuple,
 #ifdef CONFIG_NF_CONNTRACK_PROCFS
 	.print_conntrack = gre_print_conntrack,
 #endif