netfilter: conntrack: remove l3->l4 mapping information

l4 protocols are demuxed by l3num, l4num pair.

However, almost all l4 trackers are l3 agnostic.

Only exceptions are:
 - gre, icmp (ipv4 only)
 - icmpv6 (ipv6 only)

This commit gets rid of the l3 mapping, l4 trackers can now be looked up
by their IPPROTO_XXX value alone, which gets rid of the additional l3
indirection.

For icmp, ipcmp6 and gre, add a check on state->pf and
return -NF_ACCEPT in case we're asked to track e.g. icmpv6-in-ipv4,
this seems more fitting than using the generic tracker.

Additionally we can kill the 2nd l4proto definitions that were needed
for v4/v6 split -- they are now the same so we can use single l4proto
struct for each protocol, rather than two.

The EXPORT_SYMBOLs can be removed as all these object files are
part of nf_conntrack with no external references.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 2 insertions, 7 deletions

diff --git a/include/net/netfilter/nf_conntrack_l4proto.h b/include/net/netfilter/nf_conntrack_l4proto.h
index 420823a8648f..d838a93430a1 100644
--- a/include/net/netfilter/nf_conntrack_l4proto.h
+++ b/include/net/netfilter/nf_conntrack_l4proto.h
@@ -18,9 +18,6 @@
 struct seq_file;
 
 struct nf_conntrack_l4proto {
-	/* L3 Protocol number. */
-	u_int16_t l3proto;
-
 	/* L4 Protocol number. */
 	u_int8_t l4proto;
 
@@ -107,11 +104,9 @@ extern const struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
 
 #define MAX_NF_CT_PROTO 256
 
-const struct nf_conntrack_l4proto *__nf_ct_l4proto_find(u_int16_t l3proto,
-						  u_int8_t l4proto);
+const struct nf_conntrack_l4proto *__nf_ct_l4proto_find(u8 l4proto);
 
-const struct nf_conntrack_l4proto *nf_ct_l4proto_find_get(u_int16_t l3proto,
-						    u_int8_t l4proto);
+const struct nf_conntrack_l4proto *nf_ct_l4proto_find_get(u8 l4proto);
 void nf_ct_l4proto_put(const struct nf_conntrack_l4proto *p);
 
 /* Protocol pernet registration. */