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>

9 files changed, 181 insertions, 212 deletions

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 131e537..6f14008 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/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"
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index b7dd189..f4446c5 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/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
diff --git a/net/ipv4/netfilter/ipt_NETMAP.c b/net/ipv4/netfilter/ipt_NETMAP.c
deleted file mode 100644
index 85028dc..0000000
--- a/net/ipv4/netfilter/ipt_NETMAP.c
+++ /dev/null
@@ -1,101 +0,0 @@
-/* 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>
- *
- * 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/module.h>
-#include <linux/netdevice.h>
-#include <linux/netfilter.h>
-#include <linux/netfilter_ipv4.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)
-{
-	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 unsigned int
-netmap_tg(struct sk_buff *skb, const struct xt_action_param *par)
-{
-	struct nf_conn *ct;
-	enum ip_conntrack_info ctinfo;
-	__be32 new_ip, netmask;
-	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
-	struct nf_nat_range newrange;
-
-	NF_CT_ASSERT(par->hooknum == NF_INET_PRE_ROUTING ||
-		     par->hooknum == NF_INET_POST_ROUTING ||
-		     par->hooknum == NF_INET_LOCAL_OUT ||
-		     par->hooknum == NF_INET_LOCAL_IN);
-	ct = nf_ct_get(skb, &ctinfo);
-
-	netmask = ~(mr->range[0].min_ip ^ mr->range[0].max_ip);
-
-	if (par->hooknum == NF_INET_PRE_ROUTING ||
-	    par->hooknum == NF_INET_LOCAL_OUT)
-		new_ip = ip_hdr(skb)->daddr & ~netmask;
-	else
-		new_ip = ip_hdr(skb)->saddr & ~netmask;
-	new_ip |= mr->range[0].min_ip & netmask;
-
-	memset(&newrange.min_addr, 0, sizeof(newrange.min_addr));
-	memset(&newrange.max_addr, 0, sizeof(newrange.max_addr));
-	newrange.flags	     = mr->range[0].flags | NF_NAT_RANGE_MAP_IPS;
-	newrange.min_addr.ip = new_ip;
-	newrange.max_addr.ip = new_ip;
-	newrange.min_proto   = mr->range[0].min;
-	newrange.max_proto   = mr->range[0].max;
-
-	/* Hand modified range to generic setup. */
-	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 __init netmap_tg_init(void)
-{
-	return xt_register_target(&netmap_tg_reg);
-}
-
-static void __exit netmap_tg_exit(void)
-{
-	xt_unregister_target(&netmap_tg_reg);
-}
-
-module_init(netmap_tg_init);
-module_exit(netmap_tg_exit);
diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig
index d8f276b..007bb45 100644
--- a/net/ipv6/netfilter/Kconfig
+++ b/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
diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile
index 5752132..de8e0d1 100644
--- a/net/ipv6/netfilter/Makefile
+++ b/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
diff --git a/net/ipv6/netfilter/ip6t_NETMAP.c b/net/ipv6/netfilter/ip6t_NETMAP.c
deleted file mode 100644
index 4f3bf36..0000000
--- a/net/ipv6/netfilter/ip6t_NETMAP.c
+++ /dev/null
@@ -1,94 +0,0 @@
-/*
- * 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>");
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 3f4b3b4..ad0e0da 100644
--- a/net/netfilter/Kconfig
+++ b/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
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 0baa3f1..600d28b 100644
--- a/net/netfilter/Makefile
+++ b/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
diff --git a/net/netfilter/xt_NETMAP.c b/net/netfilter/xt_NETMAP.c
new file mode 100644
index 0000000..b253e07
--- /dev/null
+++ b/net/netfilter/xt_NETMAP.c
@@ -0,0 +1,165 @@
+/*
+ * (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.
+ */
+
+#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>
+
+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 unsigned int
+netmap_tg4(struct sk_buff *skb, const struct xt_action_param *par)
+{
+	struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+	__be32 new_ip, netmask;
+	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
+	struct nf_nat_range newrange;
+
+	NF_CT_ASSERT(par->hooknum == NF_INET_PRE_ROUTING ||
+		     par->hooknum == NF_INET_POST_ROUTING ||
+		     par->hooknum == NF_INET_LOCAL_OUT ||
+		     par->hooknum == NF_INET_LOCAL_IN);
+	ct = nf_ct_get(skb, &ctinfo);
+
+	netmask = ~(mr->range[0].min_ip ^ mr->range[0].max_ip);
+
+	if (par->hooknum == NF_INET_PRE_ROUTING ||
+	    par->hooknum == NF_INET_LOCAL_OUT)
+		new_ip = ip_hdr(skb)->daddr & ~netmask;
+	else
+		new_ip = ip_hdr(skb)->saddr & ~netmask;
+	new_ip |= mr->range[0].min_ip & netmask;
+
+	memset(&newrange.min_addr, 0, sizeof(newrange.min_addr));
+	memset(&newrange.max_addr, 0, sizeof(newrange.max_addr));
+	newrange.flags	     = mr->range[0].flags | NF_NAT_RANGE_MAP_IPS;
+	newrange.min_addr.ip = new_ip;
+	newrange.max_addr.ip = new_ip;
+	newrange.min_proto   = mr->range[0].min;
+	newrange.max_proto   = mr->range[0].max;
+
+	/* Hand modified range to generic setup. */
+	return nf_nat_setup_info(ct, &newrange, HOOK2MANIP(par->hooknum));
+}
+
+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_targets(netmap_tg_reg, ARRAY_SIZE(netmap_tg_reg));
+}
+
+static void netmap_tg_exit(void)
+{
+	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");