netfilter: combine IPv4 and IPv6 nf_nat_redirect code in one module

This resolves linking problems with CONFIG_IPV6=n:

net/built-in.o: In function `redirect_tg6':
xt_REDIRECT.c:(.text+0x6d021): undefined reference to `nf_nat_redirect_ipv6'

Reported-by: Andreas Ruprecht <rupran@einserver.de>
Reported-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

4 files changed, 2 insertions, 91 deletions

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 8358b2d..59f883d 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -104,12 +104,6 @@ config NF_NAT_MASQUERADE_IPV4
 	  This is the kernel functionality to provide NAT in the masquerade
 	  flavour (automatic source address selection).
 
-config NF_NAT_REDIRECT_IPV4
-	tristate "IPv4 redirect support"
-	help
-	  This is the kernel functionality to provide NAT in the redirect
-	  flavour (redirect packets to local machine).
-
 config NFT_MASQ_IPV4
 	tristate "IPv4 masquerading support for nf_tables"
 	depends on NF_TABLES_IPV4
@@ -123,7 +117,7 @@ config NFT_REDIR_IPV4
 	tristate "IPv4 redirect support for nf_tables"
 	depends on NF_TABLES_IPV4
 	depends on NFT_REDIR
-	select NF_NAT_REDIRECT_IPV4
+	select NF_NAT_REDIRECT
 	help
 	  This is the expression that provides IPv4 redirect support for
 	  nf_tables.
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index 902bcd1..7fe6c70 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -31,7 +31,6 @@ obj-$(CONFIG_NF_NAT_H323) += nf_nat_h323.o
 obj-$(CONFIG_NF_NAT_PPTP) += nf_nat_pptp.o
 obj-$(CONFIG_NF_NAT_SNMP_BASIC) += nf_nat_snmp_basic.o
 obj-$(CONFIG_NF_NAT_MASQUERADE_IPV4) += nf_nat_masquerade_ipv4.o
-obj-$(CONFIG_NF_NAT_REDIRECT_IPV4) += nf_nat_redirect_ipv4.o
 
 # NAT protocols (nf_nat)
 obj-$(CONFIG_NF_NAT_PROTO_GRE) += nf_nat_proto_gre.o
diff --git a/net/ipv4/netfilter/nf_nat_redirect_ipv4.c b/net/ipv4/netfilter/nf_nat_redirect_ipv4.c
deleted file mode 100644
index a220552..0000000
--- a/net/ipv4/netfilter/nf_nat_redirect_ipv4.c
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * (C) 1999-2001 Paul `Rusty' Russell
- * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
- * 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 Rusty Russell's IPv4 REDIRECT target. Development of IPv6
- * NAT funded by Astaro.
- */
-
-#include <linux/if.h>
-#include <linux/inetdevice.h>
-#include <linux/ip.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/netdevice.h>
-#include <linux/netfilter.h>
-#include <linux/types.h>
-#include <linux/netfilter_ipv4.h>
-#include <linux/netfilter/x_tables.h>
-#include <net/addrconf.h>
-#include <net/checksum.h>
-#include <net/protocol.h>
-#include <net/netfilter/nf_nat.h>
-#include <net/netfilter/ipv4/nf_nat_redirect.h>
-
-unsigned int
-nf_nat_redirect_ipv4(struct sk_buff *skb,
-		     const struct nf_nat_ipv4_multi_range_compat *mr,
-		     unsigned int hooknum)
-{
-	struct nf_conn *ct;
-	enum ip_conntrack_info ctinfo;
-	__be32 newdst;
-	struct nf_nat_range newrange;
-
-	NF_CT_ASSERT(hooknum == NF_INET_PRE_ROUTING ||
-		     hooknum == NF_INET_LOCAL_OUT);
-
-	ct = nf_ct_get(skb, &ctinfo);
-	NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED));
-
-	/* Local packets: make them go to loopback */
-	if (hooknum == NF_INET_LOCAL_OUT) {
-		newdst = htonl(0x7F000001);
-	} else {
-		struct in_device *indev;
-		struct in_ifaddr *ifa;
-
-		newdst = 0;
-
-		rcu_read_lock();
-		indev = __in_dev_get_rcu(skb->dev);
-		if (indev != NULL) {
-			ifa = indev->ifa_list;
-			newdst = ifa->ifa_local;
-		}
-		rcu_read_unlock();
-
-		if (!newdst)
-			return NF_DROP;
-	}
-
-	/* Transfer from original range. */
-	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 = newdst;
-	newrange.max_addr.ip = newdst;
-	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, NF_NAT_MANIP_DST);
-}
-EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv4);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
diff --git a/net/ipv4/netfilter/nft_redir_ipv4.c b/net/ipv4/netfilter/nft_redir_ipv4.c
index 643c596..ff2d23d 100644
--- a/net/ipv4/netfilter/nft_redir_ipv4.c
+++ b/net/ipv4/netfilter/nft_redir_ipv4.c
@@ -14,7 +14,7 @@
 #include <linux/netfilter/nf_tables.h>
 #include <net/netfilter/nf_tables.h>
 #include <net/netfilter/nf_nat.h>
-#include <net/netfilter/ipv4/nf_nat_redirect.h>
+#include <net/netfilter/nf_nat_redirect.h>
 #include <net/netfilter/nft_redir.h>
 
 static void nft_redir_ipv4_eval(const struct nft_expr *expr,