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>

4 files changed, 3 insertions, 781 deletions

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index bbfc356cb1b5..d9504adc47b3 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -9,22 +9,6 @@ config NF_DEFRAG_IPV4
 	tristate
 	default n
 
-config NF_CONNTRACK_IPV4
-	tristate "IPv4 connection tracking support (required for NAT)"
-	depends on NF_CONNTRACK
-	default m if NETFILTER_ADVANCED=n
-	select NF_DEFRAG_IPV4
-	---help---
-	  Connection tracking keeps a record of what packets have passed
-	  through your machine, in order to figure out how they are related
-	  into connections.
-
-	  This is IPv4 support on Layer 3 independent connection tracking.
-	  Layer 3 independent connection tracking is experimental scheme
-	  which generalize ip_conntrack to support other layer 3 protocols.
-
-	  To compile it as a module, choose M here.  If unsure, say N.
-
 config NF_SOCKET_IPV4
 	tristate "IPv4 socket lookup support"
 	help
@@ -112,7 +96,7 @@ config NF_REJECT_IPV4
 
 config NF_NAT_IPV4
 	tristate "IPv4 NAT"
-	depends on NF_CONNTRACK_IPV4
+	depends on NF_CONNTRACK
 	default m if NETFILTER_ADVANCED=n
 	select NF_NAT
 	help
@@ -279,7 +263,7 @@ config IP_NF_TARGET_SYNPROXY
 # NAT + specific targets: nf_conntrack
 config IP_NF_NAT
 	tristate "iptables NAT support"
-	depends on NF_CONNTRACK_IPV4
+	depends on NF_CONNTRACK
 	default m if NETFILTER_ADVANCED=n
 	select NF_NAT
 	select NF_NAT_IPV4
@@ -340,7 +324,7 @@ config IP_NF_MANGLE
 config IP_NF_TARGET_CLUSTERIP
 	tristate "CLUSTERIP target support"
 	depends on IP_NF_MANGLE
-	depends on NF_CONNTRACK_IPV4
+	depends on NF_CONNTRACK
 	depends on NETFILTER_ADVANCED
 	select NF_CONNTRACK_MARK
 	select NETFILTER_FAMILY_ARP
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index 8394c17c269f..367993adf4d3 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -3,12 +3,6 @@
 # Makefile for the netfilter modules on top of IPv4.
 #
 
-# objects for l3 independent conntrack
-nf_conntrack_ipv4-y	:=  nf_conntrack_l3proto_ipv4.o nf_conntrack_proto_icmp.o
-
-# connection tracking
-obj-$(CONFIG_NF_CONNTRACK_IPV4) += nf_conntrack_ipv4.o
-
 nf_nat_ipv4-y		:= nf_nat_l3proto_ipv4.o nf_nat_proto_icmp.o
 nf_nat_ipv4-$(CONFIG_NF_NAT_MASQUERADE_IPV4) += nf_nat_masquerade_ipv4.o
 obj-$(CONFIG_NF_NAT_IPV4) += nf_nat_ipv4.o
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
deleted file mode 100644
index 9fbf6c7f8ece..000000000000
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ /dev/null
@@ -1,368 +0,0 @@
-
-/* (C) 1999-2001 Paul `Rusty' Russell
- * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
- * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#include <linux/types.h>
-#include <linux/ip.h>
-#include <linux/netfilter.h>
-#include <linux/module.h>
-#include <linux/skbuff.h>
-#include <linux/icmp.h>
-#include <linux/sysctl.h>
-#include <net/route.h>
-#include <net/ip.h>
-
-#include <linux/netfilter_ipv4.h>
-#include <net/netfilter/nf_conntrack.h>
-#include <net/netfilter/nf_conntrack_helper.h>
-#include <net/netfilter/nf_conntrack_l4proto.h>
-#include <net/netfilter/nf_conntrack_l3proto.h>
-#include <net/netfilter/nf_conntrack_zones.h>
-#include <net/netfilter/nf_conntrack_core.h>
-#include <net/netfilter/nf_conntrack_seqadj.h>
-#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
-#include <net/netfilter/nf_nat_helper.h>
-#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
-#include <net/netfilter/nf_log.h>
-
-static int conntrack4_net_id __read_mostly;
-static DEFINE_MUTEX(register_ipv4_hooks);
-
-struct conntrack4_net {
-	unsigned int users;
-};
-
-static unsigned int ipv4_helper(void *priv,
-				struct sk_buff *skb,
-				const struct nf_hook_state *state)
-{
-	struct nf_conn *ct;
-	enum ip_conntrack_info ctinfo;
-	const struct nf_conn_help *help;
-	const struct nf_conntrack_helper *helper;
-
-	/* This is where we call the helper: as the packet goes out. */
-	ct = nf_ct_get(skb, &ctinfo);
-	if (!ct || ctinfo == IP_CT_RELATED_REPLY)
-		return NF_ACCEPT;
-
-	help = nfct_help(ct);
-	if (!help)
-		return NF_ACCEPT;
-
-	/* rcu_read_lock()ed by nf_hook_thresh */
-	helper = rcu_dereference(help->helper);
-	if (!helper)
-		return NF_ACCEPT;
-
-	return helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb),
-			    ct, ctinfo);
-}
-
-static unsigned int ipv4_confirm(void *priv,
-				 struct sk_buff *skb,
-				 const struct nf_hook_state *state)
-{
-	struct nf_conn *ct;
-	enum ip_conntrack_info ctinfo;
-
-	ct = nf_ct_get(skb, &ctinfo);
-	if (!ct || ctinfo == IP_CT_RELATED_REPLY)
-		goto out;
-
-	/* adjust seqs for loopback traffic only in outgoing direction */
-	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
-	    !nf_is_loopback_packet(skb)) {
-		if (!nf_ct_seq_adjust(skb, ct, ctinfo, ip_hdrlen(skb))) {
-			NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
-			return NF_DROP;
-		}
-	}
-out:
-	/* We've seen it coming out the other side: confirm it */
-	return nf_conntrack_confirm(skb);
-}
-
-static unsigned int ipv4_conntrack_in(void *priv,
-				      struct sk_buff *skb,
-				      const struct nf_hook_state *state)
-{
-	return nf_conntrack_in(state->net, PF_INET, state->hook, skb);
-}
-
-static unsigned int ipv4_conntrack_local(void *priv,
-					 struct sk_buff *skb,
-					 const struct nf_hook_state *state)
-{
-	if (ip_is_fragment(ip_hdr(skb))) { /* IP_NODEFRAG setsockopt set */
-		enum ip_conntrack_info ctinfo;
-		struct nf_conn *tmpl;
-
-		tmpl = nf_ct_get(skb, &ctinfo);
-		if (tmpl && nf_ct_is_template(tmpl)) {
-			/* when skipping ct, clear templates to avoid fooling
-			 * later targets/matches
-			 */
-			skb->_nfct = 0;
-			nf_ct_put(tmpl);
-		}
-		return NF_ACCEPT;
-	}
-
-	return nf_conntrack_in(state->net, PF_INET, state->hook, skb);
-}
-
-/* Connection tracking may drop packets, but never alters them, so
-   make it the first hook. */
-static const struct nf_hook_ops ipv4_conntrack_ops[] = {
-	{
-		.hook		= ipv4_conntrack_in,
-		.pf		= NFPROTO_IPV4,
-		.hooknum	= NF_INET_PRE_ROUTING,
-		.priority	= NF_IP_PRI_CONNTRACK,
-	},
-	{
-		.hook		= ipv4_conntrack_local,
-		.pf		= NFPROTO_IPV4,
-		.hooknum	= NF_INET_LOCAL_OUT,
-		.priority	= NF_IP_PRI_CONNTRACK,
-	},
-	{
-		.hook		= ipv4_helper,
-		.pf		= NFPROTO_IPV4,
-		.hooknum	= NF_INET_POST_ROUTING,
-		.priority	= NF_IP_PRI_CONNTRACK_HELPER,
-	},
-	{
-		.hook		= ipv4_confirm,
-		.pf		= NFPROTO_IPV4,
-		.hooknum	= NF_INET_POST_ROUTING,
-		.priority	= NF_IP_PRI_CONNTRACK_CONFIRM,
-	},
-	{
-		.hook		= ipv4_helper,
-		.pf		= NFPROTO_IPV4,
-		.hooknum	= NF_INET_LOCAL_IN,
-		.priority	= NF_IP_PRI_CONNTRACK_HELPER,
-	},
-	{
-		.hook		= ipv4_confirm,
-		.pf		= NFPROTO_IPV4,
-		.hooknum	= NF_INET_LOCAL_IN,
-		.priority	= NF_IP_PRI_CONNTRACK_CONFIRM,
-	},
-};
-
-/* Fast function for those who don't want to parse /proc (and I don't
-   blame them). */
-/* Reversing the socket's dst/src point of view gives us the reply
-   mapping. */
-static int
-getorigdst(struct sock *sk, int optval, void __user *user, int *len)
-{
-	const struct inet_sock *inet = inet_sk(sk);
-	const struct nf_conntrack_tuple_hash *h;
-	struct nf_conntrack_tuple tuple;
-
-	memset(&tuple, 0, sizeof(tuple));
-
-	lock_sock(sk);
-	tuple.src.u3.ip = inet->inet_rcv_saddr;
-	tuple.src.u.tcp.port = inet->inet_sport;
-	tuple.dst.u3.ip = inet->inet_daddr;
-	tuple.dst.u.tcp.port = inet->inet_dport;
-	tuple.src.l3num = PF_INET;
-	tuple.dst.protonum = sk->sk_protocol;
-	release_sock(sk);
-
-	/* We only do TCP and SCTP at the moment: is there a better way? */
-	if (tuple.dst.protonum != IPPROTO_TCP &&
-	    tuple.dst.protonum != IPPROTO_SCTP) {
-		pr_debug("SO_ORIGINAL_DST: Not a TCP/SCTP socket\n");
-		return -ENOPROTOOPT;
-	}
-
-	if ((unsigned int) *len < sizeof(struct sockaddr_in)) {
-		pr_debug("SO_ORIGINAL_DST: len %d not %zu\n",
-			 *len, sizeof(struct sockaddr_in));
-		return -EINVAL;
-	}
-
-	h = nf_conntrack_find_get(sock_net(sk), &nf_ct_zone_dflt, &tuple);
-	if (h) {
-		struct sockaddr_in sin;
-		struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
-
-		sin.sin_family = AF_INET;
-		sin.sin_port = ct->tuplehash[IP_CT_DIR_ORIGINAL]
-			.tuple.dst.u.tcp.port;
-		sin.sin_addr.s_addr = ct->tuplehash[IP_CT_DIR_ORIGINAL]
-			.tuple.dst.u3.ip;
-		memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
-
-		pr_debug("SO_ORIGINAL_DST: %pI4 %u\n",
-			 &sin.sin_addr.s_addr, ntohs(sin.sin_port));
-		nf_ct_put(ct);
-		if (copy_to_user(user, &sin, sizeof(sin)) != 0)
-			return -EFAULT;
-		else
-			return 0;
-	}
-	pr_debug("SO_ORIGINAL_DST: Can't find %pI4/%u-%pI4/%u.\n",
-		 &tuple.src.u3.ip, ntohs(tuple.src.u.tcp.port),
-		 &tuple.dst.u3.ip, ntohs(tuple.dst.u.tcp.port));
-	return -ENOENT;
-}
-
-static struct nf_sockopt_ops so_getorigdst = {
-	.pf		= PF_INET,
-	.get_optmin	= SO_ORIGINAL_DST,
-	.get_optmax	= SO_ORIGINAL_DST+1,
-	.get		= getorigdst,
-	.owner		= THIS_MODULE,
-};
-
-static int ipv4_hooks_register(struct net *net)
-{
-	struct conntrack4_net *cnet = net_generic(net, conntrack4_net_id);
-	int err = 0;
-
-	mutex_lock(&register_ipv4_hooks);
-
-	cnet->users++;
-	if (cnet->users > 1)
-		goto out_unlock;
-
-	err = nf_defrag_ipv4_enable(net);
-	if (err) {
-		cnet->users = 0;
-		goto out_unlock;
-	}
-
-	err = nf_register_net_hooks(net, ipv4_conntrack_ops,
-				    ARRAY_SIZE(ipv4_conntrack_ops));
-
-	if (err)
-		cnet->users = 0;
- out_unlock:
-	mutex_unlock(&register_ipv4_hooks);
-	return err;
-}
-
-static void ipv4_hooks_unregister(struct net *net)
-{
-	struct conntrack4_net *cnet = net_generic(net, conntrack4_net_id);
-
-	mutex_lock(&register_ipv4_hooks);
-	if (cnet->users && (--cnet->users == 0))
-		nf_unregister_net_hooks(net, ipv4_conntrack_ops,
-					ARRAY_SIZE(ipv4_conntrack_ops));
-	mutex_unlock(&register_ipv4_hooks);
-}
-
-const struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4 = {
-	.l3proto	 = PF_INET,
-	.net_ns_get	 = ipv4_hooks_register,
-	.net_ns_put	 = ipv4_hooks_unregister,
-	.me		 = THIS_MODULE,
-};
-
-module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
-		  &nf_conntrack_htable_size, 0600);
-
-MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
-MODULE_ALIAS("ip_conntrack");
-MODULE_LICENSE("GPL");
-
-static const struct nf_conntrack_l4proto * const builtin_l4proto4[] = {
-	&nf_conntrack_l4proto_tcp4,
-	&nf_conntrack_l4proto_udp4,
-	&nf_conntrack_l4proto_icmp,
-#ifdef CONFIG_NF_CT_PROTO_DCCP
-	&nf_conntrack_l4proto_dccp4,
-#endif
-#ifdef CONFIG_NF_CT_PROTO_SCTP
-	&nf_conntrack_l4proto_sctp4,
-#endif
-#ifdef CONFIG_NF_CT_PROTO_UDPLITE
-	&nf_conntrack_l4proto_udplite4,
-#endif
-};
-
-static int ipv4_net_init(struct net *net)
-{
-	return nf_ct_l4proto_pernet_register(net, builtin_l4proto4,
-					     ARRAY_SIZE(builtin_l4proto4));
-}
-
-static void ipv4_net_exit(struct net *net)
-{
-	nf_ct_l4proto_pernet_unregister(net, builtin_l4proto4,
-					ARRAY_SIZE(builtin_l4proto4));
-}
-
-static struct pernet_operations ipv4_net_ops = {
-	.init = ipv4_net_init,
-	.exit = ipv4_net_exit,
-	.id = &conntrack4_net_id,
-	.size = sizeof(struct conntrack4_net),
-};
-
-static int __init nf_conntrack_l3proto_ipv4_init(void)
-{
-	int ret = 0;
-
-	need_conntrack();
-
-	ret = nf_register_sockopt(&so_getorigdst);
-	if (ret < 0) {
-		pr_err("Unable to register netfilter socket option\n");
-		return ret;
-	}
-
-	ret = register_pernet_subsys(&ipv4_net_ops);
-	if (ret < 0) {
-		pr_err("nf_conntrack_ipv4: can't register pernet ops\n");
-		goto cleanup_sockopt;
-	}
-
-	ret = nf_ct_l4proto_register(builtin_l4proto4,
-				     ARRAY_SIZE(builtin_l4proto4));
-	if (ret < 0)
-		goto cleanup_pernet;
-
-	ret = nf_ct_l3proto_register(&nf_conntrack_l3proto_ipv4);
-	if (ret < 0) {
-		pr_err("nf_conntrack_ipv4: can't register ipv4 proto.\n");
-		goto cleanup_l4proto;
-	}
-
-	return ret;
-cleanup_l4proto:
-	nf_ct_l4proto_unregister(builtin_l4proto4,
-				 ARRAY_SIZE(builtin_l4proto4));
- cleanup_pernet:
-	unregister_pernet_subsys(&ipv4_net_ops);
- cleanup_sockopt:
-	nf_unregister_sockopt(&so_getorigdst);
-	return ret;
-}
-
-static void __exit nf_conntrack_l3proto_ipv4_fini(void)
-{
-	synchronize_net();
-	nf_ct_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
-	nf_ct_l4proto_unregister(builtin_l4proto4,
-				 ARRAY_SIZE(builtin_l4proto4));
-	unregister_pernet_subsys(&ipv4_net_ops);
-	nf_unregister_sockopt(&so_getorigdst);
-}
-
-module_init(nf_conntrack_l3proto_ipv4_init);
-module_exit(nf_conntrack_l3proto_ipv4_fini);
diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
deleted file mode 100644
index 036670b38282..000000000000
--- a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
+++ /dev/null
@@ -1,388 +0,0 @@
-/* (C) 1999-2001 Paul `Rusty' Russell
- * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
- * (C) 2006-2010 Patrick McHardy <kaber@trash.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#include <linux/types.h>
-#include <linux/timer.h>
-#include <linux/netfilter.h>
-#include <linux/in.h>
-#include <linux/icmp.h>
-#include <linux/seq_file.h>
-#include <net/ip.h>
-#include <net/checksum.h>
-#include <linux/netfilter_ipv4.h>
-#include <net/netfilter/nf_conntrack_tuple.h>
-#include <net/netfilter/nf_conntrack_l4proto.h>
-#include <net/netfilter/nf_conntrack_core.h>
-#include <net/netfilter/nf_conntrack_timeout.h>
-#include <net/netfilter/nf_conntrack_zones.h>
-#include <net/netfilter/nf_log.h>
-
-static const unsigned int nf_ct_icmp_timeout = 30*HZ;
-
-static inline struct nf_icmp_net *icmp_pernet(struct net *net)
-{
-	return &net->ct.nf_ct_proto.icmp;
-}
-
-static bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
-			      struct net *net, struct nf_conntrack_tuple *tuple)
-{
-	const struct icmphdr *hp;
-	struct icmphdr _hdr;
-
-	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
-	if (hp == NULL)
-		return false;
-
-	tuple->dst.u.icmp.type = hp->type;
-	tuple->src.u.icmp.id = hp->un.echo.id;
-	tuple->dst.u.icmp.code = hp->code;
-
-	return true;
-}
-
-/* Add 1; spaces filled with 0. */
-static const u_int8_t invmap[] = {
-	[ICMP_ECHO] = ICMP_ECHOREPLY + 1,
-	[ICMP_ECHOREPLY] = ICMP_ECHO + 1,
-	[ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1,
-	[ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1,
-	[ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1,
-	[ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1,
-	[ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1,
-	[ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1
-};
-
-static bool icmp_invert_tuple(struct nf_conntrack_tuple *tuple,
-			      const struct nf_conntrack_tuple *orig)
-{
-	if (orig->dst.u.icmp.type >= sizeof(invmap) ||
-	    !invmap[orig->dst.u.icmp.type])
-		return false;
-
-	tuple->src.u.icmp.id = orig->src.u.icmp.id;
-	tuple->dst.u.icmp.type = invmap[orig->dst.u.icmp.type] - 1;
-	tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
-	return true;
-}
-
-static unsigned int *icmp_get_timeouts(struct net *net)
-{
-	return &icmp_pernet(net)->timeout;
-}
-
-/* Returns verdict for packet, or -1 for invalid. */
-static int icmp_packet(struct nf_conn *ct,
-		       const struct sk_buff *skb,
-		       unsigned int dataoff,
-		       enum ip_conntrack_info ctinfo)
-{
-	/* Do not immediately delete the connection after the first
-	   successful reply to avoid excessive conntrackd traffic
-	   and also to handle correctly ICMP echo reply duplicates. */
-	unsigned int *timeout = nf_ct_timeout_lookup(ct);
-
-	if (!timeout)
-		timeout = icmp_get_timeouts(nf_ct_net(ct));
-
-	nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
-
-	return NF_ACCEPT;
-}
-
-/* Called when a new connection for this protocol found. */
-static bool icmp_new(struct nf_conn *ct, const struct sk_buff *skb,
-		     unsigned int dataoff)
-{
-	static const u_int8_t valid_new[] = {
-		[ICMP_ECHO] = 1,
-		[ICMP_TIMESTAMP] = 1,
-		[ICMP_INFO_REQUEST] = 1,
-		[ICMP_ADDRESS] = 1
-	};
-
-	if (ct->tuplehash[0].tuple.dst.u.icmp.type >= sizeof(valid_new) ||
-	    !valid_new[ct->tuplehash[0].tuple.dst.u.icmp.type]) {
-		/* Can't create a new ICMP `conn' with this. */
-		pr_debug("icmp: can't create new conn with type %u\n",
-			 ct->tuplehash[0].tuple.dst.u.icmp.type);
-		nf_ct_dump_tuple_ip(&ct->tuplehash[0].tuple);
-		return false;
-	}
-	return true;
-}
-
-/* Returns conntrack if it dealt with ICMP, and filled in skb fields */
-static int
-icmp_error_message(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
-		 unsigned int hooknum)
-{
-	struct nf_conntrack_tuple innertuple, origtuple;
-	const struct nf_conntrack_l4proto *innerproto;
-	const struct nf_conntrack_tuple_hash *h;
-	const struct nf_conntrack_zone *zone;
-	enum ip_conntrack_info ctinfo;
-	struct nf_conntrack_zone tmp;
-
-	WARN_ON(skb_nfct(skb));
-	zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
-
-	/* Are they talking about one of our connections? */
-	if (!nf_ct_get_tuplepr(skb,
-			       skb_network_offset(skb) + ip_hdrlen(skb)
-						       + sizeof(struct icmphdr),
-			       PF_INET, net, &origtuple)) {
-		pr_debug("icmp_error_message: failed to get tuple\n");
-		return -NF_ACCEPT;
-	}
-
-	/* rcu_read_lock()ed by nf_hook_thresh */
-	innerproto = __nf_ct_l4proto_find(PF_INET, origtuple.dst.protonum);
-
-	/* Ordinarily, we'd expect the inverted tupleproto, but it's
-	   been preserved inside the ICMP. */
-	if (!nf_ct_invert_tuple(&innertuple, &origtuple, innerproto)) {
-		pr_debug("icmp_error_message: no match\n");
-		return -NF_ACCEPT;
-	}
-
-	ctinfo = IP_CT_RELATED;
-
-	h = nf_conntrack_find_get(net, zone, &innertuple);
-	if (!h) {
-		pr_debug("icmp_error_message: no match\n");
-		return -NF_ACCEPT;
-	}
-
-	if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
-		ctinfo += IP_CT_IS_REPLY;
-
-	/* Update skb to refer to this connection */
-	nf_ct_set(skb, nf_ct_tuplehash_to_ctrack(h), ctinfo);
-	return NF_ACCEPT;
-}
-
-static void icmp_error_log(const struct sk_buff *skb, struct net *net,
-			   u8 pf, const char *msg)
-{
-	nf_l4proto_log_invalid(skb, net, pf, IPPROTO_ICMP, "%s", msg);
-}
-
-/* Small and modified version of icmp_rcv */
-static int
-icmp_error(struct net *net, struct nf_conn *tmpl,
-	   struct sk_buff *skb, unsigned int dataoff,
-	   u8 pf, unsigned int hooknum)
-{
-	const struct icmphdr *icmph;
-	struct icmphdr _ih;
-
-	/* Not enough header? */
-	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
-	if (icmph == NULL) {
-		icmp_error_log(skb, net, pf, "short packet");
-		return -NF_ACCEPT;
-	}
-
-	/* See ip_conntrack_proto_tcp.c */
-	if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
-	    nf_ip_checksum(skb, hooknum, dataoff, 0)) {
-		icmp_error_log(skb, net, pf, "bad hw icmp checksum");
-		return -NF_ACCEPT;
-	}
-
-	/*
-	 *	18 is the highest 'known' ICMP type. Anything else is a mystery
-	 *
-	 *	RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently
-	 *		  discarded.
-	 */
-	if (icmph->type > NR_ICMP_TYPES) {
-		icmp_error_log(skb, net, pf, "invalid icmp type");
-		return -NF_ACCEPT;
-	}
-
-	/* Need to track icmp error message? */
-	if (icmph->type != ICMP_DEST_UNREACH &&
-	    icmph->type != ICMP_SOURCE_QUENCH &&
-	    icmph->type != ICMP_TIME_EXCEEDED &&
-	    icmph->type != ICMP_PARAMETERPROB &&
-	    icmph->type != ICMP_REDIRECT)
-		return NF_ACCEPT;
-
-	return icmp_error_message(net, tmpl, skb, hooknum);
-}
-
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
-
-#include <linux/netfilter/nfnetlink.h>
-#include <linux/netfilter/nfnetlink_conntrack.h>
-
-static int icmp_tuple_to_nlattr(struct sk_buff *skb,
-				const struct nf_conntrack_tuple *t)
-{
-	if (nla_put_be16(skb, CTA_PROTO_ICMP_ID, t->src.u.icmp.id) ||
-	    nla_put_u8(skb, CTA_PROTO_ICMP_TYPE, t->dst.u.icmp.type) ||
-	    nla_put_u8(skb, CTA_PROTO_ICMP_CODE, t->dst.u.icmp.code))
-		goto nla_put_failure;
-	return 0;
-
-nla_put_failure:
-	return -1;
-}
-
-static const struct nla_policy icmp_nla_policy[CTA_PROTO_MAX+1] = {
-	[CTA_PROTO_ICMP_TYPE]	= { .type = NLA_U8 },
-	[CTA_PROTO_ICMP_CODE]	= { .type = NLA_U8 },
-	[CTA_PROTO_ICMP_ID]	= { .type = NLA_U16 },
-};
-
-static int icmp_nlattr_to_tuple(struct nlattr *tb[],
-				struct nf_conntrack_tuple *tuple)
-{
-	if (!tb[CTA_PROTO_ICMP_TYPE] ||
-	    !tb[CTA_PROTO_ICMP_CODE] ||
-	    !tb[CTA_PROTO_ICMP_ID])
-		return -EINVAL;
-
-	tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]);
-	tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMP_CODE]);
-	tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMP_ID]);
-
-	if (tuple->dst.u.icmp.type >= sizeof(invmap) ||
-	    !invmap[tuple->dst.u.icmp.type])
-		return -EINVAL;
-
-	return 0;
-}
-
-static unsigned int icmp_nlattr_tuple_size(void)
-{
-	static unsigned int size __read_mostly;
-
-	if (!size)
-		size = nla_policy_len(icmp_nla_policy, CTA_PROTO_MAX + 1);
-
-	return size;
-}
-#endif
-
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
-
-#include <linux/netfilter/nfnetlink.h>
-#include <linux/netfilter/nfnetlink_cttimeout.h>
-
-static int icmp_timeout_nlattr_to_obj(struct nlattr *tb[],
-				      struct net *net, void *data)
-{
-	unsigned int *timeout = data;
-	struct nf_icmp_net *in = icmp_pernet(net);
-
-	if (tb[CTA_TIMEOUT_ICMP_TIMEOUT]) {
-		if (!timeout)
-			timeout = &in->timeout;
-		*timeout =
-			ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMP_TIMEOUT])) * HZ;
-	} else if (timeout) {
-		/* Set default ICMP timeout. */
-		*timeout = in->timeout;
-	}
-	return 0;
-}
-
-static int
-icmp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
-{
-	const unsigned int *timeout = data;
-
-	if (nla_put_be32(skb, CTA_TIMEOUT_ICMP_TIMEOUT, htonl(*timeout / HZ)))
-		goto nla_put_failure;
-	return 0;
-
-nla_put_failure:
-	return -ENOSPC;
-}
-
-static const struct nla_policy
-icmp_timeout_nla_policy[CTA_TIMEOUT_ICMP_MAX+1] = {
-	[CTA_TIMEOUT_ICMP_TIMEOUT]	= { .type = NLA_U32 },
-};
-#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
-
-#ifdef CONFIG_SYSCTL
-static struct ctl_table icmp_sysctl_table[] = {
-	{
-		.procname	= "nf_conntrack_icmp_timeout",
-		.maxlen		= sizeof(unsigned int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec_jiffies,
-	},
-	{ }
-};
-#endif /* CONFIG_SYSCTL */
-
-static int icmp_kmemdup_sysctl_table(struct nf_proto_net *pn,
-				     struct nf_icmp_net *in)
-{
-#ifdef CONFIG_SYSCTL
-	pn->ctl_table = kmemdup(icmp_sysctl_table,
-				sizeof(icmp_sysctl_table),
-				GFP_KERNEL);
-	if (!pn->ctl_table)
-		return -ENOMEM;
-
-	pn->ctl_table[0].data = &in->timeout;
-#endif
-	return 0;
-}
-
-static int icmp_init_net(struct net *net, u_int16_t proto)
-{
-	struct nf_icmp_net *in = icmp_pernet(net);
-	struct nf_proto_net *pn = &in->pn;
-
-	in->timeout = nf_ct_icmp_timeout;
-
-	return icmp_kmemdup_sysctl_table(pn, in);
-}
-
-static struct nf_proto_net *icmp_get_net_proto(struct net *net)
-{
-	return &net->ct.nf_ct_proto.icmp.pn;
-}
-
-const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp =
-{
-	.l3proto		= PF_INET,
-	.l4proto		= IPPROTO_ICMP,
-	.pkt_to_tuple		= icmp_pkt_to_tuple,
-	.invert_tuple		= icmp_invert_tuple,
-	.packet			= icmp_packet,
-	.new			= icmp_new,
-	.error			= icmp_error,
-	.destroy		= NULL,
-	.me			= NULL,
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
-	.tuple_to_nlattr	= icmp_tuple_to_nlattr,
-	.nlattr_tuple_size	= icmp_nlattr_tuple_size,
-	.nlattr_to_tuple	= icmp_nlattr_to_tuple,
-	.nla_policy		= icmp_nla_policy,
-#endif
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
-	.ctnl_timeout		= {
-		.nlattr_to_obj	= icmp_timeout_nlattr_to_obj,
-		.obj_to_nlattr	= icmp_timeout_obj_to_nlattr,
-		.nlattr_max	= CTA_TIMEOUT_ICMP_MAX,
-		.obj_size	= sizeof(unsigned int),
-		.nla_policy	= icmp_timeout_nla_policy,
-	},
-#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
-	.init_net		= icmp_init_net,
-	.get_net_proto		= icmp_get_net_proto,
-};