netfilter: combine ipt_NETMAP and ip6t_NETMAP

Combine more modules since the actual code is so small anyway that the
kmod metadata and the module in its loaded state totally outweighs the
combined actual code size.

IP_NF_TARGET_NETMAP becomes a compat option; IP6_NF_TARGET_NETMAP
is completely eliminated since it has not see a release yet.
Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/ipv4/netfilter/Kconfig

@@ -172,12 +172,11 @@ config IP_NF_TARGET_MASQUERADE
 config IP_NF_TARGET_NETMAP
 	tristate "NETMAP target support"
 	depends on NETFILTER_ADVANCED
-	help
-	  NETMAP is an implementation of static 1:1 NAT mapping of network
-	  addresses. It maps the network address part, while keeping the host
-	  address part intact.
-
-	  To compile it as a module, choose M here.  If unsure, say N.
+	select NETFILTER_XT_TARGET_NETMAP
+	---help---
+	This is a backwards-compat option for the user's convenience
+	(e.g. when running oldconfig). It selects
+	CONFIG_NETFILTER_XT_TARGET_NETMAP.
 
 config IP_NF_TARGET_REDIRECT
 	tristate "REDIRECT target support"

net/ipv4/netfilter/Makefile

@@ -45,7 +45,6 @@ obj-$(CONFIG_IP_NF_MATCH_RPFILTER) += ipt_rpfilter.o
 obj-$(CONFIG_IP_NF_TARGET_CLUSTERIP) += ipt_CLUSTERIP.o
 obj-$(CONFIG_IP_NF_TARGET_ECN) += ipt_ECN.o
 obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o
-obj-$(CONFIG_IP_NF_TARGET_NETMAP) += ipt_NETMAP.o
 obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o
 obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o
 obj-$(CONFIG_IP_NF_TARGET_ULOG) += ipt_ULOG.o

net/ipv6/netfilter/Kconfig

@@ -209,15 +209,6 @@ config IP6_NF_TARGET_MASQUERADE
 
 	  To compile it as a module, choose M here.  If unsure, say N.
 
-config IP6_NF_TARGET_NETMAP
-	tristate "NETMAP target support"
-	help
-	  NETMAP is an implementation of static 1:1 NAT mapping of network
-	  addresses. It maps the network address part, while keeping the host
-	  address part intact.
-
-	  To compile it as a module, choose M here.  If unsure, say N.
-
 config IP6_NF_TARGET_REDIRECT
 	tristate "REDIRECT target support"
 	help

net/ipv6/netfilter/Makefile

@@ -35,7 +35,6 @@ obj-$(CONFIG_IP6_NF_MATCH_RT) += ip6t_rt.o
 
 # targets
 obj-$(CONFIG_IP6_NF_TARGET_MASQUERADE) += ip6t_MASQUERADE.o
-obj-$(CONFIG_IP6_NF_TARGET_NETMAP) += ip6t_NETMAP.o
 obj-$(CONFIG_IP6_NF_TARGET_NPT) += ip6t_NPT.o
 obj-$(CONFIG_IP6_NF_TARGET_REDIRECT) += ip6t_REDIRECT.o
 obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o

net/ipv6/netfilter/ip6t_NETMAP.c

-/*
- * Copyright (c) 2011 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.
- *
- * Based on Svenning Soerensen's IPv4 NETMAP target. Development of IPv6
- * NAT funded by Astaro.
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/ipv6.h>
-#include <linux/netfilter.h>
-#include <linux/netfilter_ipv6.h>
-#include <linux/netfilter/x_tables.h>
-#include <net/netfilter/nf_nat.h>
-
-static unsigned int
-netmap_tg6(struct sk_buff *skb, const struct xt_action_param *par)
-{
-	const struct nf_nat_range *range = par->targinfo;
-	struct nf_nat_range newrange;
-	struct nf_conn *ct;
-	enum ip_conntrack_info ctinfo;
-	union nf_inet_addr new_addr, netmask;
-	unsigned int i;
-
-	ct = nf_ct_get(skb, &ctinfo);
-	for (i = 0; i < ARRAY_SIZE(range->min_addr.ip6); i++)
-		netmask.ip6[i] = ~(range->min_addr.ip6[i] ^
-				   range->max_addr.ip6[i]);
-
-	if (par->hooknum == NF_INET_PRE_ROUTING ||
-	    par->hooknum == NF_INET_LOCAL_OUT)
-		new_addr.in6 = ipv6_hdr(skb)->daddr;
-	else
-		new_addr.in6 = ipv6_hdr(skb)->saddr;
-
-	for (i = 0; i < ARRAY_SIZE(new_addr.ip6); i++) {
-		new_addr.ip6[i] &= ~netmask.ip6[i];
-		new_addr.ip6[i] |= range->min_addr.ip6[i] &
-				   netmask.ip6[i];
-	}
-
-	newrange.flags	= range->flags | NF_NAT_RANGE_MAP_IPS;
-	newrange.min_addr	= new_addr;
-	newrange.max_addr	= new_addr;
-	newrange.min_proto	= range->min_proto;
-	newrange.max_proto	= range->max_proto;
-
-	return nf_nat_setup_info(ct, &newrange, HOOK2MANIP(par->hooknum));
-}
-
-static int netmap_tg6_checkentry(const struct xt_tgchk_param *par)
-{
-	const struct nf_nat_range *range = par->targinfo;
-
-	if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
-		return -EINVAL;
-	return 0;
-}
-
-static struct xt_target netmap_tg6_reg __read_mostly = {
-	.name		= "NETMAP",
-	.family		= NFPROTO_IPV6,
-	.target		= netmap_tg6,
-	.targetsize	= sizeof(struct nf_nat_range),
-	.table		= "nat",
-	.hooks		= (1 << NF_INET_PRE_ROUTING) |
-			  (1 << NF_INET_POST_ROUTING) |
-			  (1 << NF_INET_LOCAL_OUT) |
-			  (1 << NF_INET_LOCAL_IN),
-	.checkentry	= netmap_tg6_checkentry,
-	.me		= THIS_MODULE,
-};
-
-static int __init netmap_tg6_init(void)
-{
-	return xt_register_target(&netmap_tg6_reg);
-}
-
-static void netmap_tg6_exit(void)
-{
-	xt_unregister_target(&netmap_tg6_reg);
-}
-
-module_init(netmap_tg6_init);
-module_exit(netmap_tg6_exit);
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("Xtables: 1:1 NAT mapping of IPv6 subnets");
-MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");

net/netfilter/Kconfig

@@ -648,6 +648,16 @@ config NETFILTER_XT_TARGET_MARK
 	(e.g. when running oldconfig). It selects
 	CONFIG_NETFILTER_XT_MARK (combined mark/MARK module).
 
+config NETFILTER_XT_TARGET_NETMAP
+	tristate '"NETMAP" target support'
+	depends on NF_NAT
+	---help---
+	NETMAP is an implementation of static 1:1 NAT mapping of network
+	addresses. It maps the network address part, while keeping the host
+	address part intact.
+
+	To compile it as a module, choose M here. If unsure, say N.
+
 config NETFILTER_XT_TARGET_NFLOG
 	tristate '"NFLOG" target support'
 	default m if NETFILTER_ADVANCED=n

net/netfilter/Makefile

@@ -83,6 +83,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_HL) += xt_HL.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_HMARK) += xt_HMARK.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_LOG) += xt_LOG.o
+obj-$(CONFIG_NETFILTER_XT_TARGET_NETMAP) += xt_NETMAP.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_NFLOG) += xt_NFLOG.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE) += xt_NFQUEUE.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_RATEEST) += xt_RATEEST.o

net/ipv4/netfilter/ipt_NETMAP.c → net/netfilter/xt_NETMAP.c

-/* NETMAP - static NAT mapping of IP network addresses (1:1).
- * The mapping can be applied to source (POSTROUTING),
- * destination (PREROUTING), or both (with separate rules).
- */
-
-/* (C) 2000-2001 Svenning Soerensen <svenning@post5.tele.dk>
+/*
+ * (C) 2000-2001 Svenning Soerensen <svenning@post5.tele.dk>
+ * Copyright (c) 2011 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.
  */
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/ip.h>
+#include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/netdevice.h>
+#include <linux/ipv6.h>
 #include <linux/netfilter.h>
 #include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv6.h>
 #include <linux/netfilter/x_tables.h>
 #include <net/netfilter/nf_nat.h>
 
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Svenning Soerensen <svenning@post5.tele.dk>");
-MODULE_DESCRIPTION("Xtables: 1:1 NAT mapping of IPv4 subnets");
-
-static int netmap_tg_check(const struct xt_tgchk_param *par)
+static unsigned int
+netmap_tg6(struct sk_buff *skb, const struct xt_action_param *par)
 {
-	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
+	const struct nf_nat_range *range = par->targinfo;
+	struct nf_nat_range newrange;
+	struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+	union nf_inet_addr new_addr, netmask;
+	unsigned int i;
 
-	if (!(mr->range[0].flags & NF_NAT_RANGE_MAP_IPS)) {
-		pr_debug("bad MAP_IPS.\n");
-		return -EINVAL;
+	ct = nf_ct_get(skb, &ctinfo);
+	for (i = 0; i < ARRAY_SIZE(range->min_addr.ip6); i++)
+		netmask.ip6[i] = ~(range->min_addr.ip6[i] ^
+				   range->max_addr.ip6[i]);
+
+	if (par->hooknum == NF_INET_PRE_ROUTING ||
+	    par->hooknum == NF_INET_LOCAL_OUT)
+		new_addr.in6 = ipv6_hdr(skb)->daddr;
+	else
+		new_addr.in6 = ipv6_hdr(skb)->saddr;
+
+	for (i = 0; i < ARRAY_SIZE(new_addr.ip6); i++) {
+		new_addr.ip6[i] &= ~netmask.ip6[i];
+		new_addr.ip6[i] |= range->min_addr.ip6[i] &
+				   netmask.ip6[i];
 	}
-	if (mr->rangesize != 1) {
-		pr_debug("bad rangesize %u.\n", mr->rangesize);
+
+	newrange.flags	= range->flags | NF_NAT_RANGE_MAP_IPS;
+	newrange.min_addr	= new_addr;
+	newrange.max_addr	= new_addr;
+	newrange.min_proto	= range->min_proto;
+	newrange.max_proto	= range->max_proto;
+
+	return nf_nat_setup_info(ct, &newrange, HOOK2MANIP(par->hooknum));
+}
+
+static int netmap_tg6_checkentry(const struct xt_tgchk_param *par)
+{
+	const struct nf_nat_range *range = par->targinfo;
+
+	if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
 		return -EINVAL;
-	}
 	return 0;
 }
 
 static unsigned int
-netmap_tg(struct sk_buff *skb, const struct xt_action_param *par)
+netmap_tg4(struct sk_buff *skb, const struct xt_action_param *par)
 {
 	struct nf_conn *ct;
 	enum ip_conntrack_info ctinfo;
@@ -73,29 +99,67 @@ netmap_tg(struct sk_buff *skb, const struct xt_action_param *par)
 	return nf_nat_setup_info(ct, &newrange, HOOK2MANIP(par->hooknum));
 }
 
-static struct xt_target netmap_tg_reg __read_mostly = {
-	.name 		= "NETMAP",
-	.family		= NFPROTO_IPV4,
-	.target 	= netmap_tg,
-	.targetsize	= sizeof(struct nf_nat_ipv4_multi_range_compat),
-	.table		= "nat",
-	.hooks		= (1 << NF_INET_PRE_ROUTING) |
-			  (1 << NF_INET_POST_ROUTING) |
-			  (1 << NF_INET_LOCAL_OUT) |
-			  (1 << NF_INET_LOCAL_IN),
-	.checkentry 	= netmap_tg_check,
-	.me 		= THIS_MODULE
+static int netmap_tg4_check(const struct xt_tgchk_param *par)
+{
+	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
+
+	if (!(mr->range[0].flags & NF_NAT_RANGE_MAP_IPS)) {
+		pr_debug("bad MAP_IPS.\n");
+		return -EINVAL;
+	}
+	if (mr->rangesize != 1) {
+		pr_debug("bad rangesize %u.\n", mr->rangesize);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static struct xt_target netmap_tg_reg[] __read_mostly = {
+	{
+		.name       = "NETMAP",
+		.family     = NFPROTO_IPV6,
+		.revision   = 0,
+		.target     = netmap_tg6,
+		.targetsize = sizeof(struct nf_nat_range),
+		.table      = "nat",
+		.hooks      = (1 << NF_INET_PRE_ROUTING) |
+		              (1 << NF_INET_POST_ROUTING) |
+		              (1 << NF_INET_LOCAL_OUT) |
+		              (1 << NF_INET_LOCAL_IN),
+		.checkentry = netmap_tg6_checkentry,
+		.me         = THIS_MODULE,
+	},
+	{
+		.name       = "NETMAP",
+		.family     = NFPROTO_IPV4,
+		.revision   = 0,
+		.target     = netmap_tg4,
+		.targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat),
+		.table      = "nat",
+		.hooks      = (1 << NF_INET_PRE_ROUTING) |
+		              (1 << NF_INET_POST_ROUTING) |
+		              (1 << NF_INET_LOCAL_OUT) |
+		              (1 << NF_INET_LOCAL_IN),
+		.checkentry = netmap_tg4_check,
+		.me         = THIS_MODULE,
+	},
 };
 
 static int __init netmap_tg_init(void)
 {
-	return xt_register_target(&netmap_tg_reg);
+	return xt_register_targets(netmap_tg_reg, ARRAY_SIZE(netmap_tg_reg));
 }
 
-static void __exit netmap_tg_exit(void)
+static void netmap_tg_exit(void)
 {
-	xt_unregister_target(&netmap_tg_reg);
+	xt_unregister_targets(netmap_tg_reg, ARRAY_SIZE(netmap_tg_reg));
 }
 
 module_init(netmap_tg_init);
 module_exit(netmap_tg_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Xtables: 1:1 NAT mapping of subnets");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_ALIAS("ip6t_NETMAP");
+MODULE_ALIAS("ipt_NETMAP");