netfilter: conntrack: remove l3proto abstraction

This unifies ipv4 and ipv6 protocol trackers and removes the l3proto
abstraction.

This gets rid of all l3proto indirect calls and the need to do
a lookup on the function to call for l3 demux.

It increases module size by only a small amount (12kbyte), so this reduces
size because nf_conntrack.ko is useless without either nf_conntrack_ipv4
or nf_conntrack_ipv6 module.

before:
   text    data     bss     dec     hex filename
   7357    1088       0    8445    20fd nf_conntrack_ipv4.ko
   7405    1084       4    8493    212d nf_conntrack_ipv6.ko
  72614   13689     236   86539   1520b nf_conntrack.ko
 19K nf_conntrack_ipv4.ko
 19K nf_conntrack_ipv6.ko
179K nf_conntrack.ko

after:
   text    data     bss     dec     hex filename
  79277   13937     236   93450   16d0a nf_conntrack.ko
  191K nf_conntrack.ko

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

5 files changed, 5 insertions, 62 deletions

diff --git a/include/net/netfilter/ipv4/nf_conntrack_ipv4.h b/include/net/netfilter/ipv4/nf_conntrack_ipv4.h
index 73f825732326..c84b51682f08 100644
--- a/include/net/netfilter/ipv4/nf_conntrack_ipv4.h
+++ b/include/net/netfilter/ipv4/nf_conntrack_ipv4.h
@@ -10,9 +10,6 @@
 #ifndef _NF_CONNTRACK_IPV4_H
 #define _NF_CONNTRACK_IPV4_H
 
-
-const extern struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4;
-
 extern const struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4;
 extern const struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4;
 extern const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp;
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 062dc19b5840..a2b0ed025908 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -41,6 +41,11 @@ union nf_conntrack_expect_proto {
 	/* insert expect proto private data here */
 };
 
+struct nf_conntrack_net {
+	unsigned int users4;
+	unsigned int users6;
+};
+
 #include <linux/types.h>
 #include <linux/skbuff.h>
 
diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h
index 35461b2d3462..2a3e0974a6af 100644
--- a/include/net/netfilter/nf_conntrack_core.h
+++ b/include/net/netfilter/nf_conntrack_core.h
@@ -14,7 +14,6 @@
 #define _NF_CONNTRACK_CORE_H
 
 #include <linux/netfilter.h>
-#include <net/netfilter/nf_conntrack_l3proto.h>
 #include <net/netfilter/nf_conntrack_l4proto.h>
 #include <net/netfilter/nf_conntrack_ecache.h>
 
diff --git a/include/net/netfilter/nf_conntrack_l3proto.h b/include/net/netfilter/nf_conntrack_l3proto.h
deleted file mode 100644
index 5f160375c93a..000000000000
--- a/include/net/netfilter/nf_conntrack_l3proto.h
+++ /dev/null
@@ -1,54 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Copyright (C)2003,2004 USAGI/WIDE Project
- *
- * Header for use in defining a given L3 protocol for connection tracking.
- *
- * Author:
- *	Yasuyuki Kozakai @USAGI	<yasuyuki.kozakai@toshiba.co.jp>
- *
- * Derived from include/netfilter_ipv4/ip_conntrack_protocol.h
- */
-
-#ifndef _NF_CONNTRACK_L3PROTO_H
-#define _NF_CONNTRACK_L3PROTO_H
-#include <linux/netlink.h>
-#include <net/netlink.h>
-#include <linux/seq_file.h>
-#include <net/netfilter/nf_conntrack.h>
-
-struct nf_conntrack_l3proto {
-	/* L3 Protocol Family number. ex) PF_INET */
-	u_int16_t l3proto;
-
-	/* size of tuple nlattr, fills a hole */
-	u16 nla_size;
-
-	/* Called when netns wants to use connection tracking */
-	int (*net_ns_get)(struct net *);
-	void (*net_ns_put)(struct net *);
-
-	/* Module (if any) which this is connected to. */
-	struct module *me;
-};
-
-extern struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[NFPROTO_NUMPROTO];
-
-/* Protocol global registration. */
-int nf_ct_l3proto_register(const struct nf_conntrack_l3proto *proto);
-void nf_ct_l3proto_unregister(const struct nf_conntrack_l3proto *proto);
-
-const struct nf_conntrack_l3proto *nf_ct_l3proto_find_get(u_int16_t l3proto);
-
-/* Existing built-in protocols */
-extern struct nf_conntrack_l3proto nf_conntrack_l3proto_generic;
-
-static inline struct nf_conntrack_l3proto *
-__nf_ct_l3proto_find(u_int16_t l3proto)
-{
-	if (unlikely(l3proto >= NFPROTO_NUMPROTO))
-		return &nf_conntrack_l3proto_generic;
-	return rcu_dereference(nf_ct_l3protos[l3proto]);
-}
-
-#endif /*_NF_CONNTRACK_L3PROTO_H*/
diff --git a/include/net/netfilter/nf_conntrack_l4proto.h b/include/net/netfilter/nf_conntrack_l4proto.h
index c7a0075d96df..6068c6da3eac 100644
--- a/include/net/netfilter/nf_conntrack_l4proto.h
+++ b/include/net/netfilter/nf_conntrack_l4proto.h
@@ -130,10 +130,6 @@ void nf_ct_l4proto_pernet_unregister(struct net *net,
 /* Protocol global registration. */
 int nf_ct_l4proto_register_one(const struct nf_conntrack_l4proto *proto);
 void nf_ct_l4proto_unregister_one(const struct nf_conntrack_l4proto *proto);
-int nf_ct_l4proto_register(const struct nf_conntrack_l4proto * const proto[],
-			   unsigned int num_proto);
-void nf_ct_l4proto_unregister(const struct nf_conntrack_l4proto * const proto[],
-			      unsigned int num_proto);
 
 /* Generic netlink helpers */
 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,