[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables

This monster-patch tries to do the best job for unifying the data
structures and backend interfaces for the three evil clones ip_tables,
ip6_tables and arp_tables.  In an ideal world we would never have
allowed this kind of copy+paste programming... but well, our world
isn't (yet?) ideal.

o introduce a new x_tables module
o {ip,arp,ip6}_tables depend on this x_tables module
o registration functions for tables, matches and targets are only
  wrappers around x_tables provided functions
o all matches/targets that are used from ip_tables and ip6_tables
  are now implemented as xt_FOOBAR.c files and provide module aliases
  to ipt_FOOBAR and ip6t_FOOBAR
o header files for xt_matches are in include/linux/netfilter/,
  include/linux/netfilter_{ipv4,ipv6} contains compatibility wrappers
  around the xt_FOOBAR.h headers

Based on this patchset we're going to further unify the code,
gradually getting rid of all the layer 3 specific assumptions.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

27 files changed, 4316 insertions, 5 deletions

diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 7d55f9cbd85..99c0a0fa4a9 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -103,3 +103,261 @@ config NF_CT_NETLINK
 	  This option enables support for a netlink-based userspace interface
 
 endmenu
+
+config NETFILTER_XTABLES
+	tristate "Netfilter Xtables support (required for ip_tables)"
+	help
+	  This is required if you intend to use any of ip_tables,
+	  ip6_tables or arp_tables.
+
+# alphabetically ordered list of targets
+
+config NETFILTER_XT_TARGET_CLASSIFY
+	tristate '"CLASSIFY" target support'
+	depends on NETFILTER_XTABLES
+	help
+	  This option adds a `CLASSIFY' target, which enables the user to set
+	  the priority of a packet. Some qdiscs can use this value for
+	  classification, among these are:
+
+  	  atm, cbq, dsmark, pfifo_fast, htb, prio
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NETFILTER_XT_TARGET_CONNMARK
+	tristate  '"CONNMARK" target support'
+	depends on NETFILTER_XTABLES
+	depends on IP_NF_MANGLE || IP6_NF_MANGLE
+	depends on (IP_NF_CONNTRACK && IP_NF_CONNTRACK_MARK) || (NF_CONNTRACK_MARK && NF_CONNTRACK_IPV4)
+	help
+	  This option adds a `CONNMARK' target, which allows one to manipulate
+	  the connection mark value.  Similar to the MARK target, but
+	  affects the connection mark value rather than the packet mark value.
+	
+	  If you want to compile it as a module, say M here and read
+	  <file:Documentation/modules.txt>.  The module will be called
+	  ipt_CONNMARK.o.  If unsure, say `N'.
+
+config NETFILTER_XT_TARGET_MARK
+	tristate '"MARK" target support'
+	depends on NETFILTER_XTABLES
+	help
+	  This option adds a `MARK' target, which allows you to create rules
+	  in the `mangle' table which alter the netfilter mark (nfmark) field
+	  associated with the packet prior to routing. This can change
+	  the routing method (see `Use netfilter MARK value as routing
+	  key') and can also be used by other subsystems to change their
+	  behavior.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NETFILTER_XT_TARGET_NFQUEUE
+	tristate '"NFQUEUE" target Support'
+	depends on NETFILTER_XTABLES
+	help
+	  This Target replaced the old obsolete QUEUE target.
+
+	  As opposed to QUEUE, it supports 65535 different queues,
+	  not just one.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NETFILTER_XT_TARGET_NOTRACK
+	tristate  '"NOTRACK" target support'
+	depends on NETFILTER_XTABLES
+	depends on IP_NF_RAW || IP6_NF_RAW
+	depends on IP_NF_CONNTRACK || NF_CONNTRACK
+	help
+	  The NOTRACK target allows a select rule to specify
+	  which packets *not* to enter the conntrack/NAT
+	  subsystem with all the consequences (no ICMP error tracking,
+	  no protocol helpers for the selected packets).
+	
+	  If you want to compile it as a module, say M here and read
+	  <file:Documentation/modules.txt>.  If unsure, say `N'.
+
+config NETFILTER_XT_MATCH_COMMENT
+	tristate  '"comment" match support'
+	depends on NETFILTER_XTABLES
+	help
+	  This option adds a `comment' dummy-match, which allows you to put
+	  comments in your iptables ruleset.
+
+	  If you want to compile it as a module, say M here and read
+	  <file:Documentation/modules.txt>.  If unsure, say `N'.
+
+config NETFILTER_XT_MATCH_CONNBYTES
+	tristate  '"connbytes" per-connection counter match support'
+	depends on NETFILTER_XTABLES
+	depends on (IP_NF_CONNTRACK && IP_NF_CT_ACCT) || NF_CT_ACCT
+	help
+	  This option adds a `connbytes' match, which allows you to match the
+	  number of bytes and/or packets for each direction within a connection.
+
+	  If you want to compile it as a module, say M here and read
+	  <file:Documentation/modules.txt>.  If unsure, say `N'.
+
+config NETFILTER_XT_MATCH_CONNMARK
+	tristate  '"connmark" connection mark match support'
+	depends on NETFILTER_XTABLES
+	depends on (IP_NF_CONNTRACK && IP_NF_CONNTRACK_MARK) || NF_CONNTRACK_MARK
+	help
+	  This option adds a `connmark' match, which allows you to match the
+	  connection mark value previously set for the session by `CONNMARK'. 
+	
+	  If you want to compile it as a module, say M here and read
+	  <file:Documentation/modules.txt>.  The module will be called
+	  ipt_connmark.o.  If unsure, say `N'.
+
+config NETFILTER_XT_MATCH_CONNTRACK
+	tristate '"conntrack" connection tracking match support'
+	depends on NETFILTER_XTABLES
+	depends on IP_NF_CONNTRACK || NF_CONNTRACK
+	help
+	  This is a general conntrack match module, a superset of the state match.
+
+	  It allows matching on additional conntrack information, which is
+	  useful in complex configurations, such as NAT gateways with multiple
+	  internet links or tunnels.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NETFILTER_XT_MATCH_DCCP
+	tristate  '"DCCP" protocol match support'
+	depends on NETFILTER_XTABLES
+	help
+	  With this option enabled, you will be able to use the iptables
+	  `dccp' match in order to match on DCCP source/destination ports
+	  and DCCP flags.
+
+	  If you want to compile it as a module, say M here and read
+	  <file:Documentation/modules.txt>.  If unsure, say `N'.
+
+config NETFILTER_XT_MATCH_HELPER
+	tristate '"helper" match support'
+	depends on NETFILTER_XTABLES
+	depends on IP_NF_CONNTRACK || NF_CONNTRACK
+	help
+	  Helper matching allows you to match packets in dynamic connections
+	  tracked by a conntrack-helper, ie. ip_conntrack_ftp
+
+	  To compile it as a module, choose M here.  If unsure, say Y.
+
+config NETFILTER_XT_MATCH_LENGTH
+	tristate '"length" match support'
+	depends on NETFILTER_XTABLES
+	help
+	  This option allows you to match the length of a packet against a
+	  specific value or range of values.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NETFILTER_XT_MATCH_LIMIT
+	tristate '"limit" match support'
+	depends on NETFILTER_XTABLES
+	help
+	  limit matching allows you to control the rate at which a rule can be
+	  matched: mainly useful in combination with the LOG target ("LOG
+	  target support", below) and to avoid some Denial of Service attacks.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NETFILTER_XT_MATCH_MAC
+	tristate '"mac" address match support'
+	depends on NETFILTER_XTABLES
+	help
+	  MAC matching allows you to match packets based on the source
+	  Ethernet address of the packet.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NETFILTER_XT_MATCH_MARK
+	tristate '"mark" match support'
+	depends on NETFILTER_XTABLES
+	help
+	  Netfilter mark matching allows you to match packets based on the
+	  `nfmark' value in the packet.  This can be set by the MARK target
+	  (see below).
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NETFILTER_XT_MATCH_PHYSDEV
+	tristate '"physdev" match support'
+	depends on NETFILTER_XTABLES && BRIDGE_NETFILTER
+	help
+	  Physdev packet matching matches against the physical bridge ports
+	  the IP packet arrived on or will leave by.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NETFILTER_XT_MATCH_PKTTYPE
+	tristate '"pkttype" packet type match support'
+	depends on NETFILTER_XTABLES
+	help
+	  Packet type matching allows you to match a packet by
+	  its "class", eg. BROADCAST, MULTICAST, ...
+
+	  Typical usage:
+	  iptables -A INPUT -m pkttype --pkt-type broadcast -j LOG
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NETFILTER_XT_MATCH_REALM
+	tristate  '"realm" match support'
+	depends on NETFILTER_XTABLES
+	select NET_CLS_ROUTE
+	help
+	  This option adds a `realm' match, which allows you to use the realm
+	  key from the routing subsystem inside iptables.
+	
+	  This match pretty much resembles the CONFIG_NET_CLS_ROUTE4 option 
+	  in tc world.
+	
+	  If you want to compile it as a module, say M here and read
+	  <file:Documentation/modules.txt>.  If unsure, say `N'.
+
+config NETFILTER_XT_MATCH_SCTP
+	tristate  '"sctp" protocol match support'
+	depends on NETFILTER_XTABLES
+	help
+	  With this option enabled, you will be able to use the 
+	  `sctp' match in order to match on SCTP source/destination ports
+	  and SCTP chunk types.
+
+	  If you want to compile it as a module, say M here and read
+	  <file:Documentation/modules.txt>.  If unsure, say `N'.
+
+config NETFILTER_XT_MATCH_STATE
+	tristate '"state" match support'
+	depends on NETFILTER_XTABLES
+	depends on IP_NF_CONNTRACK || NF_CONNTRACK
+	help
+	  Connection state matching allows you to match packets based on their
+	  relationship to a tracked connection (ie. previous packets).  This
+	  is a powerful tool for packet classification.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NETFILTER_XT_MATCH_STRING
+	tristate  '"string" match support'
+	depends on NETFILTER_XTABLES
+	select TEXTSEARCH
+	select TEXTSEARCH_KMP
+	select TEXTSEARCH_BM
+	select TEXTSEARCH_FSM
+	help
+	  This option adds a `string' match, which allows you to look for
+	  pattern matchings in packets.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NETFILTER_XT_MATCH_TCPMSS
+	tristate '"tcpmss" match support'
+	depends on NETFILTER_XTABLES
+	help
+	  This option adds a `tcpmss' match, which allows you to examine the
+	  MSS value of TCP SYN packets, which control the maximum packet size
+	  for that connection.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index cb2183145c3..746172ebc91 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -1,4 +1,5 @@
 netfilter-objs := core.o nf_log.o nf_queue.o nf_sockopt.o
+nf_conntrack-objs	:= nf_conntrack_core.o nf_conntrack_standalone.o nf_conntrack_l3proto_generic.o nf_conntrack_proto_generic.o nf_conntrack_proto_tcp.o nf_conntrack_proto_udp.o
 
 obj-$(CONFIG_NETFILTER) = netfilter.o
 
@@ -6,13 +7,43 @@ obj-$(CONFIG_NETFILTER_NETLINK) += nfnetlink.o
 obj-$(CONFIG_NETFILTER_NETLINK_QUEUE) += nfnetlink_queue.o
 obj-$(CONFIG_NETFILTER_NETLINK_LOG) += nfnetlink_log.o
 
-nf_conntrack-objs	:= nf_conntrack_core.o nf_conntrack_standalone.o nf_conntrack_l3proto_generic.o nf_conntrack_proto_generic.o nf_conntrack_proto_tcp.o nf_conntrack_proto_udp.o
-
+# connection tracking
 obj-$(CONFIG_NF_CONNTRACK) += nf_conntrack.o
-obj-$(CONFIG_NF_CONNTRACK_FTP) += nf_conntrack_ftp.o
 
 # SCTP protocol connection tracking
 obj-$(CONFIG_NF_CT_PROTO_SCTP) += nf_conntrack_proto_sctp.o
 
 # netlink interface for nf_conntrack
 obj-$(CONFIG_NF_CT_NETLINK) += nf_conntrack_netlink.o
+
+# connection tracking helpers
+obj-$(CONFIG_NF_CONNTRACK_FTP) += nf_conntrack_ftp.o
+
+# generic X tables 
+obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o
+
+# targets
+obj-$(CONFIG_NETFILTER_XT_TARGET_CLASSIFY) += xt_CLASSIFY.o
+obj-$(CONFIG_NETFILTER_XT_TARGET_CONNMARK) += xt_CONNMARK.o
+obj-$(CONFIG_NETFILTER_XT_TARGET_MARK) += xt_MARK.o
+obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE) += xt_NFQUEUE.o
+obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK) += xt_NOTRACK.o
+
+# matches
+obj-$(CONFIG_NETFILTER_XT_MATCH_COMMENT) += xt_comment.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_CONNBYTES) += xt_connbytes.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_CONNMARK) += xt_connmark.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_CONNTRACK) += xt_conntrack.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_DCCP) += xt_dccp.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_HELPER) += xt_helper.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_LENGTH) += xt_length.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_LIMIT) += xt_limit.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_MAC) += xt_mac.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_MARK) += xt_mark.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_PKTTYPE) += xt_pkttype.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_REALM) += xt_realm.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_SCTP) += xt_sctp.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_STATE) += xt_state.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_STRING) += xt_string.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS) += xt_tcpmss.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_PHYSDEV) += xt_physdev.o
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 3531d142f69..617599aeeea 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -821,7 +821,7 @@ module_exit(fini);
 
 /* Some modules need us, but don't depend directly on any symbol.
    They should call this. */
-void need_nf_conntrack(void)
+void need_conntrack(void)
 {
 }
 
@@ -841,7 +841,7 @@ EXPORT_SYMBOL(nf_conntrack_protocol_unregister);
 EXPORT_SYMBOL(nf_ct_invert_tuplepr);
 EXPORT_SYMBOL(nf_conntrack_alter_reply);
 EXPORT_SYMBOL(nf_conntrack_destroyed);
-EXPORT_SYMBOL(need_nf_conntrack);
+EXPORT_SYMBOL(need_conntrack);
 EXPORT_SYMBOL(nf_conntrack_helper_register);
 EXPORT_SYMBOL(nf_conntrack_helper_unregister);
 EXPORT_SYMBOL(nf_ct_iterate_cleanup);
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
new file mode 100644
index 00000000000..d7817afc6b9
--- /dev/null
+++ b/net/netfilter/x_tables.c
@@ -0,0 +1,624 @@
+/*
+ * x_tables core - Backend for {ip,ip6,arp}_tables
+ *
+ * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
+ *
+ * Based on existing ip_tables code which is
+ *   Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
+ *   Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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/config.h>
+#include <linux/kernel.h>
+#include <linux/socket.h>
+#include <linux/net.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_arp.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
+MODULE_DESCRIPTION("[ip,ip6,arp]_tables backend module");
+
+#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
+
+struct xt_af {
+	struct semaphore mutex;
+	struct list_head match;
+	struct list_head target;
+	struct list_head tables;
+};
+
+static struct xt_af *xt;
+
+#ifdef DEBUG_IP_FIREWALL_USER
+#define duprintf(format, args...) printk(format , ## args)
+#else
+#define duprintf(format, args...)
+#endif
+
+enum {
+	TABLE,
+	TARGET,
+	MATCH,
+};
+
+/* Registration hooks for targets. */
+int
+xt_register_target(int af, struct xt_target *target)
+{
+	int ret;
+
+	ret = down_interruptible(&xt[af].mutex);
+	if (ret != 0)
+		return ret;
+	list_add(&target->list, &xt[af].target);
+	up(&xt[af].mutex);
+	return ret;
+}
+EXPORT_SYMBOL(xt_register_target);
+
+void
+xt_unregister_target(int af, struct xt_target *target)
+{
+	down(&xt[af].mutex);
+	LIST_DELETE(&xt[af].target, target);
+	up(&xt[af].mutex);
+}
+EXPORT_SYMBOL(xt_unregister_target);
+
+int
+xt_register_match(int af, struct xt_match *match)
+{
+	int ret;
+
+	ret = down_interruptible(&xt[af].mutex);
+	if (ret != 0)
+		return ret;
+
+	list_add(&match->list, &xt[af].match);
+	up(&xt[af].mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL(xt_register_match);
+
+void
+xt_unregister_match(int af, struct xt_match *match)
+{
+	down(&xt[af].mutex);
+	LIST_DELETE(&xt[af].match, match);
+	up(&xt[af].mutex);
+}
+EXPORT_SYMBOL(xt_unregister_match);
+
+
+/*
+ * These are weird, but module loading must not be done with mutex
+ * held (since they will register), and we have to have a single
+ * function to use try_then_request_module().
+ */
+
+/* Find match, grabs ref.  Returns ERR_PTR() on error. */
+struct xt_match *xt_find_match(int af, const char *name, u8 revision)
+{
+	struct xt_match *m;
+	int err = 0;
+
+	if (down_interruptible(&xt[af].mutex) != 0)
+		return ERR_PTR(-EINTR);
+
+	list_for_each_entry(m, &xt[af].match, list) {
+		if (strcmp(m->name, name) == 0) {
+			if (m->revision == revision) {
+				if (try_module_get(m->me)) {
+					up(&xt[af].mutex);
+					return m;
+				}
+			} else
+				err = -EPROTOTYPE; /* Found something. */
+		}
+	}
+	up(&xt[af].mutex);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL(xt_find_match);
+
+/* Find target, grabs ref.  Returns ERR_PTR() on error. */
+struct xt_target *xt_find_target(int af, const char *name, u8 revision)
+{
+	struct xt_target *t;
+	int err = 0;
+
+	if (down_interruptible(&xt[af].mutex) != 0)
+		return ERR_PTR(-EINTR);
+
+	list_for_each_entry(t, &xt[af].target, list) {
+		if (strcmp(t->name, name) == 0) {
+			if (t->revision == revision) {
+				if (try_module_get(t->me)) {
+					up(&xt[af].mutex);
+					return t;
+				}
+			} else
+				err = -EPROTOTYPE; /* Found something. */
+		}
+	}
+	up(&xt[af].mutex);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL(xt_find_target);
+
+static const char *xt_prefix[NPROTO] = {
+	[AF_INET] 	= "ipt_%s",
+	[AF_INET6] 	= "ip6t_%s",
+	[NF_ARP]	= "arpt_%s",
+};
+
+struct xt_target *xt_request_find_target(int af, const char *name, u8 revision)
+{
+	struct xt_target *target;
+
+	target = try_then_request_module(xt_find_target(af, name, revision),
+					 xt_prefix[af], name);
+	if (IS_ERR(target) || !target)
+		return NULL;
+	return target;
+}
+EXPORT_SYMBOL_GPL(xt_request_find_target);
+
+static int match_revfn(int af, const char *name, u8 revision, int *bestp)
+{
+	struct xt_match *m;
+	int have_rev = 0;
+
+	list_for_each_entry(m, &xt[af].match, list) {
+		if (strcmp(m->name, name) == 0) {
+			if (m->revision > *bestp)
+				*bestp = m->revision;
+			if (m->revision == revision)
+				have_rev = 1;
+		}
+	}
+	return have_rev;
+}
+
+static int target_revfn(int af, const char *name, u8 revision, int *bestp)
+{
+	struct xt_target *t;
+	int have_rev = 0;
+
+	list_for_each_entry(t, &xt[af].target, list) {
+		if (strcmp(t->name, name) == 0) {
+			if (t->revision > *bestp)
+				*bestp = t->revision;
+			if (t->revision == revision)
+				have_rev = 1;
+		}
+	}
+	return have_rev;
+}
+
+/* Returns true or false (if no such extension at all) */
+int xt_find_revision(int af, const char *name, u8 revision, int target,
+		     int *err)
+{
+	int have_rev, best = -1;
+
+	if (down_interruptible(&xt[af].mutex) != 0) {
+		*err = -EINTR;
+		return 1;
+	}
+	if (target == 1)
+		have_rev = target_revfn(af, name, revision, &best);
+	else
+		have_rev = match_revfn(af, name, revision, &best);
+	up(&xt[af].mutex);
+
+	/* Nothing at all?  Return 0 to try loading module. */
+	if (best == -1) {
+		*err = -ENOENT;
+		return 0;
+	}
+
+	*err = best;
+	if (!have_rev)
+		*err = -EPROTONOSUPPORT;
+	return 1;
+}
+EXPORT_SYMBOL_GPL(xt_find_revision);
+
+struct xt_table_info *xt_alloc_table_info(unsigned int size)
+{
+	struct xt_table_info *newinfo;
+	int cpu;
+
+	/* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
+	if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > num_physpages)
+		return NULL;
+
+	newinfo = kzalloc(sizeof(struct xt_table_info), GFP_KERNEL);
+	if (!newinfo)
+		return NULL;
+
+	newinfo->size = size;
+
+	for_each_cpu(cpu) {
+		if (size <= PAGE_SIZE)
+			newinfo->entries[cpu] = kmalloc_node(size,
+							GFP_KERNEL,
+							cpu_to_node(cpu));
+		else
+			newinfo->entries[cpu] = vmalloc_node(size,
+							cpu_to_node(cpu));
+
+		if (newinfo->entries[cpu] == NULL) {
+			xt_free_table_info(newinfo);
+			return NULL;
+		}
+	}
+
+	return newinfo;
+}
+EXPORT_SYMBOL(xt_alloc_table_info);
+
+void xt_free_table_info(struct xt_table_info *info)
+{
+	int cpu;
+
+	for_each_cpu(cpu) {
+		if (info->size <= PAGE_SIZE)
+			kfree(info->entries[cpu]);
+		else
+			vfree(info->entries[cpu]);
+	}
+	kfree(info);
+}
+EXPORT_SYMBOL(xt_free_table_info);
+
+/* Find table by name, grabs mutex & ref.  Returns ERR_PTR() on error. */
+struct xt_table *xt_find_table_lock(int af, const char *name)
+{
+	struct xt_table *t;
+
+	if (down_interruptible(&xt[af].mutex) != 0)
+		return ERR_PTR(-EINTR);
+
+	list_for_each_entry(t, &xt[af].tables, list)
+		if (strcmp(t->name, name) == 0 && try_module_get(t->me))
+			return t;
+	up(&xt[af].mutex);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(xt_find_table_lock);
+
+void xt_table_unlock(struct xt_table *table)
+{
+	up(&xt[table->af].mutex);
+}
+EXPORT_SYMBOL_GPL(xt_table_unlock);
+
+
+struct xt_table_info *
+xt_replace_table(struct xt_table *table,
+	      unsigned int num_counters,
+	      struct xt_table_info *newinfo,
+	      int *error)
+{
+	struct xt_table_info *oldinfo, *private;
+
+	/* Do the substitution. */
+	write_lock_bh(&table->lock);
+	private = table->private;
+	/* Check inside lock: is the old number correct? */
+	if (num_counters != private->number) {
+		duprintf("num_counters != table->private->number (%u/%u)\n",
+			 num_counters, private->number);
+		write_unlock_bh(&table->lock);
+		*error = -EAGAIN;
+		return NULL;
+	}
+	oldinfo = private;
+	table->private = newinfo;
+	newinfo->initial_entries = oldinfo->initial_entries;
+	write_unlock_bh(&table->lock);
+
+	return oldinfo;
+}
+EXPORT_SYMBOL_GPL(xt_replace_table);
+
+int xt_register_table(struct xt_table *table,
+		      struct xt_table_info *bootstrap,
+		      struct xt_table_info *newinfo)
+{
+	int ret;
+	struct xt_table_info *private;
+
+	ret = down_interruptible(&xt[table->af].mutex);
+	if (ret != 0)
+		return ret;
+
+	/* Don't autoload: we'd eat our tail... */
+	if (list_named_find(&xt[table->af].tables, table->name)) {
+		ret = -EEXIST;
+		goto unlock;
+	}
+
+	/* Simplifies replace_table code. */
+	table->private = bootstrap;
+	if (!xt_replace_table(table, 0, newinfo, &ret))
+		goto unlock;
+
+	private = table->private;
+	duprintf("table->private->number = %u\n", private->number);
+
+	/* save number of initial entries */
+	private->initial_entries = private->number;
+
+	rwlock_init(&table->lock);
+	list_prepend(&xt[table->af].tables, table);
+
+	ret = 0;
+ unlock:
+	up(&xt[table->af].mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(xt_register_table);
+
+void *xt_unregister_table(struct xt_table *table)
+{
+	struct xt_table_info *private;
+
+	down(&xt[table->af].mutex);
+	private = table->private;
+	LIST_DELETE(&xt[table->af].tables, table);
+	up(&xt[table->af].mutex);
+
+	return private;
+}
+EXPORT_SYMBOL_GPL(xt_unregister_table);
+
+#ifdef CONFIG_PROC_FS
+static char *xt_proto_prefix[NPROTO] = {
+	[AF_INET]	= "ip",
+	[AF_INET6]	= "ip6",
+	[NF_ARP]	= "arp",
+};
+
+static struct list_head *xt_get_idx(struct list_head *list, struct seq_file *seq, loff_t pos)
+{
+	struct list_head *head = list->next;
+
+	if (!head || list_empty(list))
+		return NULL;
+
+	while (pos && (head = head->next)) {
+		if (head == list)
+			return NULL;
+		pos--;
+	}
+	return pos ? NULL : head;
+}
+
+static struct list_head *type2list(u_int16_t af, u_int16_t type)
+{
+	struct list_head *list;
+
+	switch (type) {
+	case TARGET:
+		list = &xt[af].target;
+		break;
+	case MATCH:
+		list = &xt[af].match;
+		break;
+	case TABLE:
+		list = &xt[af].tables;
+		break;
+	default:
+		list = NULL;
+		break;
+	}
+
+	return list;
+}
+
+static void *xt_tgt_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct proc_dir_entry *pde = (struct proc_dir_entry *) seq->private;
+	u_int16_t af = (unsigned long)pde->data & 0xffff;
+	u_int16_t type = (unsigned long)pde->data >> 16;
+	struct list_head *list;
+
+	if (af >= NPROTO)
+		return NULL;
+
+	list = type2list(af, type);
+	if (!list)
+		return NULL;
+
+	if (down_interruptible(&xt[af].mutex) != 0)
+		return NULL;
+	
+	return xt_get_idx(list, seq, *pos);
+}
+
+static void *xt_tgt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct proc_dir_entry *pde = seq->private;
+	u_int16_t af = (unsigned long)pde->data & 0xffff;
+	u_int16_t type = (unsigned long)pde->data >> 16;
+	struct list_head *list;
+
+	if (af >= NPROTO)
+		return NULL;
+	
+	list = type2list(af, type);
+	if (!list)
+		return NULL;
+
+	(*pos)++;
+	return xt_get_idx(list, seq, *pos);
+}
+
+static void xt_tgt_seq_stop(struct seq_file *seq, void *v)
+{
+	struct proc_dir_entry *pde = seq->private;
+	u_int16_t af = (unsigned long)pde->data & 0xffff;
+
+	up(&xt[af].mutex);
+}
+
+static int xt_name_seq_show(struct seq_file *seq, void *v)
+{
+	char *name = (char *)v + sizeof(struct list_head);
+
+	if (strlen(name))
+		return seq_printf(seq, "%s\n", name);
+	else
+		return 0;
+}
+
+static struct seq_operations xt_tgt_seq_ops = {
+	.start	= xt_tgt_seq_start,
+	.next	= xt_tgt_seq_next,
+	.stop	= xt_tgt_seq_stop,
+	.show	= xt_name_seq_show,
+};
+
+static int xt_tgt_open(struct inode *inode, struct file *file)
+{
+	int ret;
+
+	ret = seq_open(file, &xt_tgt_seq_ops);
+	if (!ret) {
+		struct seq_file *seq = file->private_data;
+		struct proc_dir_entry *pde = PDE(inode);
+
+		seq->private = pde;
+	}
+
+	return ret;
+}
+
+static struct file_operations xt_file_ops = {
+	.owner	 = THIS_MODULE,
+	.open	 = xt_tgt_open,
+	.read	 = seq_read,
+	.llseek	 = seq_lseek,
+	.release = seq_release,
+};
+
+#define FORMAT_TABLES	"_tables_names"
+#define	FORMAT_MATCHES	"_tables_matches"
+#define FORMAT_TARGETS 	"_tables_targets"
+
+#endif /* CONFIG_PROC_FS */
+
+int xt_proto_init(int af)
+{
+#ifdef CONFIG_PROC_FS
+	char buf[XT_FUNCTION_MAXNAMELEN];
+	struct proc_dir_entry *proc;
+#endif
+
+	if (af >= NPROTO)
+		return -EINVAL;
+
+
+#ifdef CONFIG_PROC_FS
+	strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
+	strlcat(buf, FORMAT_TABLES, sizeof(buf));
+	proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
+	if (!proc)
+		goto out;
+	proc->data = (void *) ((unsigned long) af | (TABLE << 16));
+
+
+	strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
+	strlcat(buf, FORMAT_MATCHES, sizeof(buf));
+	proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
+	if (!proc)
+		goto out_remove_tables;
+	proc->data = (void *) ((unsigned long) af | (MATCH << 16));
+
+	strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
+	strlcat(buf, FORMAT_TARGETS, sizeof(buf));
+	proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
+	if (!proc)
+		goto ou