src: ip: switch implicit dependencies to meta l4proto too

after ip6 nexthdr also switch ip to meta l4proto instead of ip protocol.

While its needed for ipv6 (due to extension headers) this isn't needed
for ip but it has the advantage that

tcp dport 22

produces same expressions for ip/ip6/inet families.

Signed-off-by: Florian Westphal <fw@strlen.de>

1 files changed, 11 insertions, 6 deletions

diff --git a/src/payload.c b/src/payload.c
index 8796ee57..11b6df37 100644
--- a/src/payload.c
+++ b/src/payload.c
@@ -118,17 +118,22 @@ static const struct expr_ops payload_expr_ops = {
 };
 
 /*
- * ipv6 is special case, we normally use 'meta l4proto' to fetch the last
- * l4 header of the ipv6 extension header chain so we will also match
+ * We normally use 'meta l4proto' to fetch the last l4 header of the
+ * ipv6 extension header chain so we will also match
  * tcp after a fragmentation header, for instance.
+ * For consistency we also use meta l4proto for ipv4.
  *
- * If user specifically asks for nexthdr x, treat is as a full
- * dependency rather than injecting another (useless) meta l4 one.
+ * If user specifically asks for nexthdr x, don't add another (useless)
+ * meta dependency.
  */
 static bool proto_key_is_protocol(const struct proto_desc *desc, unsigned int type)
 {
-	if (type == desc->protocol_key ||
-	    (desc == &proto_ip6 && type == IP6HDR_NEXTHDR))
+	if (type == desc->protocol_key)
+		return true;
+
+	if (desc == &proto_ip6 && type == IP6HDR_NEXTHDR)
+		return true;
+	if (desc == &proto_ip && type == IPHDR_PROTOCOL)
 		return true;
 
 	return false;