[XFRM] STATE: Allow non IPsec protocol.

It will be added two more transformation protocols (routing header
and destination options header) for Mobile IPv6.
xfrm_id_proto_match() can be handle zero as all, IPSEC_PROTO_ANY as
all IPsec and otherwise as exact one.
Based on MIPL2 kernel patch.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/xfrm.h

@@ -838,7 +838,10 @@ static inline int xfrm_state_kern(struct xfrm_state *x)
 
 static inline int xfrm_id_proto_match(u8 proto, u8 userproto)
 {
-	return (userproto == IPSEC_PROTO_ANY || proto == userproto);
+	return (!userproto || proto == userproto ||
+		(userproto == IPSEC_PROTO_ANY && (proto == IPPROTO_AH ||
+						  proto == IPPROTO_ESP ||
+						  proto == IPPROTO_COMP)));
 }
 
 /*

net/xfrm/xfrm_user.c

@@ -542,7 +542,7 @@ static int xfrm_dump_sa(struct sk_buff *skb, struct netlink_callback *cb)
 	info.nlmsg_flags = NLM_F_MULTI;
 	info.this_idx = 0;
 	info.start_idx = cb->args[0];
-	(void) xfrm_state_walk(IPSEC_PROTO_ANY, dump_one_state, &info);
+	(void) xfrm_state_walk(0, dump_one_state, &info);
 	cb->args[0] = info.this_idx;
 
 	return skb->len;