[nf_tables PATCH v2 1/3] netfilter: refactor NAT redirect IPv4 to use it from nf_tables

[nf_tables PATCH v2 1/3] netfilter: refactor NAT redirect IPv4 to use it from nf_tables

[Arturo Borrero Gonzalez]

This patch refactors the IPv4 code so it can be usable both from xt and
nf_tables.

A similar patch follows-up to handle IPv6.

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
---
v2: some cosmetic changes requested by Pablo. Select NF_NAT_REDIRECT_IPV4.

 include/net/netfilter/ipv4/nf_nat_redirect.h |    9 +++
 net/ipv4/netfilter/Kconfig                   |    6 ++
 net/ipv4/netfilter/Makefile                  |    1 
 net/ipv4/netfilter/nf_nat_redirect_ipv4.c    |   82 ++++++++++++++++++++++++++
 net/netfilter/Kconfig                        |    1 
 net/netfilter/xt_REDIRECT.c                  |   44 +-------------
 6 files changed, 101 insertions(+), 42 deletions(-)
 create mode 100644 include/net/netfilter/ipv4/nf_nat_redirect.h
 create mode 100644 net/ipv4/netfilter/nf_nat_redirect_ipv4.c

diff --git a/include/net/netfilter/ipv4/nf_nat_redirect.h b/include/net/netfilter/ipv4/nf_nat_redirect.h
new file mode 100644
index 0000000..19e1df3
--- /dev/null
+++ b/include/net/netfilter/ipv4/nf_nat_redirect.h
@@ -0,0 +1,9 @@
+#ifndef _NF_NAT_REDIRECT_IPV4_H_
+#define _NF_NAT_REDIRECT_IPV4_H_
+
+unsigned int
+nf_nat_redirect_ipv4(struct sk_buff *skb,
+		     const struct nf_nat_ipv4_multi_range_compat *mr,
+		     unsigned int hooknum);
+
+#endif /* _NF_NAT_REDIRECT_IPV4_H_ */
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 4c019d5..a300e2c 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -104,6 +104,12 @@ 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
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index f4cef5a..34e436c 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -31,6 +31,7 @@ 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
new file mode 100644
index 0000000..a220552
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_redirect_ipv4.c
@@ -0,0 +1,82 @@
+/*
+ * (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/netfilter/Kconfig b/net/netfilter/Kconfig
index ae5096a..a0716a3 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -835,6 +835,7 @@ config NETFILTER_XT_TARGET_RATEEST
 config NETFILTER_XT_TARGET_REDIRECT
 	tristate "REDIRECT target support"
 	depends on NF_NAT
+	select NF_NAT_REDIRECT_IPV4
 	---help---
 	REDIRECT is a special case of NAT: all incoming connections are
 	mapped onto the incoming interface's address, causing the packets to
diff --git a/net/netfilter/xt_REDIRECT.c b/net/netfilter/xt_REDIRECT.c
index 22a1030..b4ffac5 100644
--- a/net/netfilter/xt_REDIRECT.c
+++ b/net/netfilter/xt_REDIRECT.c
@@ -26,6 +26,7 @@
 #include <net/checksum.h>
 #include <net/protocol.h>
 #include <net/netfilter/nf_nat.h>
+#include <net/netfilter/ipv4/nf_nat_redirect.h>
 
 static const struct in6_addr loopback_addr = IN6ADDR_LOOPBACK_INIT;
 
@@ -98,48 +99,7 @@ static int redirect_tg4_check(const struct xt_tgchk_param *par)
 static unsigned int
 redirect_tg4(struct sk_buff *skb, const struct xt_action_param *par)
 {
-	struct nf_conn *ct;
-	enum ip_conntrack_info ctinfo;
-	__be32 newdst;
-	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_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 (par->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 && (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);
+	return nf_nat_redirect_ipv4(skb, par->targinfo, par->hooknum);
 }
 
 static struct xt_target redirect_tg_reg[] __read_mostly = {

[nf_tables PATCH v2 2/3] netfilter: refactor NAT redirect IPv6 code to use it from nf_tables

[Arturo Borrero Gonzalez]

This patch refactors the IPv6 code so it can be usable both from xt and
nf_tables.

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
---
v2: some cosmetic changes requested by Pablo. Select NF_NAT_REDIRECT_IPV6.

 include/net/netfilter/ipv6/nf_nat_redirect.h |    9 +++
 net/ipv6/netfilter/Kconfig                   |    6 ++
 net/ipv6/netfilter/Makefile                  |    1 
 net/ipv6/netfilter/nf_nat_redirect_ipv6.c    |   75 ++++++++++++++++++++++++++
 net/netfilter/Kconfig                        |    1 
 net/netfilter/xt_REDIRECT.c                  |   40 +-------------
 6 files changed, 94 insertions(+), 38 deletions(-)
 create mode 100644 include/net/netfilter/ipv6/nf_nat_redirect.h
 create mode 100644 net/ipv6/netfilter/nf_nat_redirect_ipv6.c

diff --git a/include/net/netfilter/ipv6/nf_nat_redirect.h b/include/net/netfilter/ipv6/nf_nat_redirect.h
new file mode 100644
index 0000000..aab7617
--- /dev/null
+++ b/include/net/netfilter/ipv6/nf_nat_redirect.h
@@ -0,0 +1,9 @@
+#ifndef _NF_NAT_REDIRECT_IPV6_H_
+#define _NF_NAT_REDIRECT_IPV6_H_
+
+unsigned int
+nf_nat_redirect_ipv6(struct sk_buff *skb, const struct nf_nat_range *range,
+		     unsigned int hooknum);
+
+#endif /* _NF_NAT_REDIRECT_IPV6_H_ */
+
diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig
index 6af874f..462eebb 100644
--- a/net/ipv6/netfilter/Kconfig
+++ b/net/ipv6/netfilter/Kconfig
@@ -82,6 +82,12 @@ config NF_NAT_MASQUERADE_IPV6
 	  This is the kernel functionality to provide NAT in the masquerade
 	  flavour (automatic source address selection) for IPv6.
 
+config NF_NAT_REDIRECT_IPV6
+	tristate "IPv6 redirect support"
+	help
+	  This is the kernel functionality to provide NAT in the redirect
+	  flavour (redirect packet to local machine) for IPv6.
+
 config NFT_MASQ_IPV6
 	tristate "IPv6 masquerade support for nf_tables"
 	depends on NF_TABLES_IPV6
diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile
index fbb25f0..6c2baab 100644
--- a/net/ipv6/netfilter/Makefile
+++ b/net/ipv6/netfilter/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_NF_CONNTRACK_IPV6) += nf_conntrack_ipv6.o
 nf_nat_ipv6-y		:= nf_nat_l3proto_ipv6.o nf_nat_proto_icmpv6.o
 obj-$(CONFIG_NF_NAT_IPV6) += nf_nat_ipv6.o
 obj-$(CONFIG_NF_NAT_MASQUERADE_IPV6) += nf_nat_masquerade_ipv6.o
+obj-$(CONFIG_NF_NAT_REDIRECT_IPV6) += nf_nat_redirect_ipv6.o
 
 # defrag
 nf_defrag_ipv6-y := nf_defrag_ipv6_hooks.o nf_conntrack_reasm.o
diff --git a/net/ipv6/netfilter/nf_nat_redirect_ipv6.c b/net/ipv6/netfilter/nf_nat_redirect_ipv6.c
new file mode 100644
index 0000000..ea1308a
--- /dev/null
+++ b/net/ipv6/netfilter/nf_nat_redirect_ipv6.c
@@ -0,0 +1,75 @@
+/*
+ * (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_ipv6.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/ipv6/nf_nat_redirect.h>
+
+static const struct in6_addr loopback_addr = IN6ADDR_LOOPBACK_INIT;
+
+unsigned int
+nf_nat_redirect_ipv6(struct sk_buff *skb, const struct nf_nat_range *range,
+		     unsigned int hooknum)
+{
+	struct nf_nat_range newrange;
+	struct in6_addr newdst;
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (hooknum == NF_INET_LOCAL_OUT) {
+		newdst = loopback_addr;
+	} else {
+		struct inet6_dev *idev;
+		struct inet6_ifaddr *ifa;
+		bool addr = false;
+
+		rcu_read_lock();
+		idev = __in6_dev_get(skb->dev);
+		if (idev != NULL) {
+			list_for_each_entry(ifa, &idev->addr_list, if_list) {
+				newdst = ifa->addr;
+				addr = true;
+				break;
+			}
+		}
+		rcu_read_unlock();
+
+		if (!addr)
+			return NF_DROP;
+	}
+
+	newrange.flags		= range->flags | NF_NAT_RANGE_MAP_IPS;
+	newrange.min_addr.in6	= newdst;
+	newrange.max_addr.in6	= newdst;
+	newrange.min_proto	= range->min_proto;
+	newrange.max_proto	= range->max_proto;
+
+	return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST);
+}
+EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv6);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index a0716a3..f54b5f8 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -836,6 +836,7 @@ config NETFILTER_XT_TARGET_REDIRECT
 	tristate "REDIRECT target support"
 	depends on NF_NAT
 	select NF_NAT_REDIRECT_IPV4
+	select NF_NAT_REDIRECT_IPV6
 	---help---
 	REDIRECT is a special case of NAT: all incoming connections are
 	mapped onto the incoming interface's address, causing the packets to
diff --git a/net/netfilter/xt_REDIRECT.c b/net/netfilter/xt_REDIRECT.c
index b4ffac5..b6ec67e 100644
--- a/net/netfilter/xt_REDIRECT.c
+++ b/net/netfilter/xt_REDIRECT.c
@@ -27,48 +27,12 @@
 #include <net/protocol.h>
 #include <net/netfilter/nf_nat.h>
 #include <net/netfilter/ipv4/nf_nat_redirect.h>
-
-static const struct in6_addr loopback_addr = IN6ADDR_LOOPBACK_INIT;
+#include <net/netfilter/ipv6/nf_nat_redirect.h>
 
 static unsigned int
 redirect_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 in6_addr newdst;
-	enum ip_conntrack_info ctinfo;
-	struct nf_conn *ct;
-
-	ct = nf_ct_get(skb, &ctinfo);
-	if (par->hooknum == NF_INET_LOCAL_OUT)
-		newdst = loopback_addr;
-	else {
-		struct inet6_dev *idev;
-		struct inet6_ifaddr *ifa;
-		bool addr = false;
-
-		rcu_read_lock();
-		idev = __in6_dev_get(skb->dev);
-		if (idev != NULL) {
-			list_for_each_entry(ifa, &idev->addr_list, if_list) {
-				newdst = ifa->addr;
-				addr = true;
-				break;
-			}
-		}
-		rcu_read_unlock();
-
-		if (!addr)
-			return NF_DROP;
-	}
-
-	newrange.flags		= range->flags | NF_NAT_RANGE_MAP_IPS;
-	newrange.min_addr.in6	= newdst;
-	newrange.max_addr.in6	= newdst;
-	newrange.min_proto	= range->min_proto;
-	newrange.max_proto	= range->max_proto;
-
-	return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST);
+	return nf_nat_redirect_ipv6(skb, par->targinfo, par->hooknum);
 }
 
 static int redirect_tg6_checkentry(const struct xt_tgchk_param *par)

[nf_tables PATCH v2 3/3] netfilter: nf_tables: add new expression nft_redir

[Arturo Borrero Gonzalez]

This new expression provides NAT in the redirect flavour, which is to
redirect packets to local machine.

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
---
v2: some cosmetic changes requested by Pablo. Use u16 for flags.

 include/net/netfilter/nft_redir.h        |   18 ++++++
 include/uapi/linux/netfilter/nf_tables.h |   16 ++++++
 net/ipv4/netfilter/Kconfig               |    9 +++
 net/ipv4/netfilter/Makefile              |    1 
 net/ipv4/netfilter/nft_redir_ipv4.c      |   76 +++++++++++++++++++++++++++
 net/ipv6/netfilter/Kconfig               |    9 +++
 net/ipv6/netfilter/Makefile              |    1 
 net/netfilter/Kconfig                    |    9 +++
 net/netfilter/Makefile                   |    1 
 net/netfilter/nft_redir.c                |   86 ++++++++++++++++++++++++++++++
 10 files changed, 226 insertions(+)
 create mode 100644 include/net/netfilter/nft_redir.h
 create mode 100644 net/ipv4/netfilter/nft_redir_ipv4.c
 create mode 100644 net/netfilter/nft_redir.c

diff --git a/include/net/netfilter/nft_redir.h b/include/net/netfilter/nft_redir.h
new file mode 100644
index 0000000..af0621d
--- /dev/null
+++ b/include/net/netfilter/nft_redir.h
@@ -0,0 +1,18 @@
+#ifndef _NFT_REDIR_H_
+#define _NFT_REDIR_H_
+
+struct nft_redir {
+	enum nft_registers	sreg_proto_min:8;
+	enum nft_registers	sreg_proto_max:8;
+	u16			flags;
+};
+
+extern const struct nla_policy nft_redir_policy[];
+
+int nft_redir_init(const struct nft_ctx *ctx,
+		   const struct nft_expr *expr,
+		   const struct nlattr * const tb[]);
+
+int nft_redir_dump(struct sk_buff *skb, const struct nft_expr *expr);
+
+#endif /* _NFT_REDIR_H_ */
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index c26df67..bb21315 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -838,6 +838,22 @@ enum nft_masq_attributes {
 #define NFTA_MASQ_MAX		(__NFTA_MASQ_MAX - 1)
 
 /**
+ * enum nft_redir_attributes - nf_tables redirect expression netlink attributes
+ *
+ * @NFTA_REDIR_REG_PROTO_MIN: source register of proto range start (NLA_U32: nft_registers)
+ * @NFTA_REDIR_REG_PROTO_MAX: source register of proto range end (NLA_U32: nft_registers)
+ * @NFTA_REDIR_FLAGS: NAT flags (see NF_NAT_RANGE_* in linux/netfilter/nf_nat.h) (NLA_U32)
+ */
+enum nft_redir_attributes {
+	NFTA_REDIR_UNSPEC,
+	NFTA_REDIR_REG_PROTO_MIN,
+	NFTA_REDIR_REG_PROTO_MAX,
+	NFTA_REDIR_FLAGS,
+	__NFTA_REDIR_MAX
+};
+#define NFTA_REDIR_MAX		(__NFTA_REDIR_MAX - 1)
+
+/**
  * enum nft_gen_attributes - nf_tables ruleset generation attributes
  *
  * @NFTA_GEN_ID: Ruleset generation ID (NLA_U32)
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index a300e2c..8358b2d 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -119,6 +119,15 @@ config NFT_MASQ_IPV4
 	  This is the expression that provides IPv4 masquerading support for
 	  nf_tables.
 
+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
+	help
+	  This is the expression that provides IPv4 redirect support for
+	  nf_tables.
+
 config NF_NAT_SNMP_BASIC
 	tristate "Basic SNMP-ALG support"
 	depends on NF_CONNTRACK_SNMP
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index 34e436c..902bcd1 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_NFT_CHAIN_ROUTE_IPV4) += nft_chain_route_ipv4.o
 obj-$(CONFIG_NFT_CHAIN_NAT_IPV4) += nft_chain_nat_ipv4.o
 obj-$(CONFIG_NFT_REJECT_IPV4) += nft_reject_ipv4.o
 obj-$(CONFIG_NFT_MASQ_IPV4) += nft_masq_ipv4.o
+obj-$(CONFIG_NFT_REDIR_IPV4) += nft_redir_ipv4.o
 obj-$(CONFIG_NF_TABLES_ARP) += nf_tables_arp.o
 
 # generic IP tables 
diff --git a/net/ipv4/netfilter/nft_redir_ipv4.c b/net/ipv4/netfilter/nft_redir_ipv4.c
new file mode 100644
index 0000000..d48690e
--- /dev/null
+++ b/net/ipv4/netfilter/nft_redir_ipv4.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#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/nft_redir.h>
+
+static void nft_redir_ipv4_eval(const struct nft_expr *expr,
+				struct nft_data data[NFT_REG_MAX + 1],
+				const struct nft_pktinfo *pkt)
+{
+	struct nft_redir *priv = nft_expr_priv(expr);
+	struct nf_nat_ipv4_multi_range_compat mr;
+	unsigned int verdict;
+
+	memset(&mr, 0, sizeof(mr));
+	if (priv->sreg_proto_min) {
+		mr.range[0].min.all = (__force __be16)
+					data[priv->sreg_proto_min].data[0];
+		mr.range[0].max.all = (__force __be16)
+					data[priv->sreg_proto_max].data[0];
+		mr.range[0].flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
+	}
+
+	mr.range[0].flags |= priv->flags;
+
+	verdict = nf_nat_redirect_ipv4(pkt->skb, &mr, pkt->ops->hooknum);
+	data[NFT_REG_VERDICT].verdict = verdict;
+}
+
+static struct nft_expr_type nft_redir_ipv4_type;
+static const struct nft_expr_ops nft_redir_ipv4_ops = {
+	.type		= &nft_redir_ipv4_type,
+	.size		= NFT_EXPR_SIZE(sizeof(struct nft_redir)),
+	.eval		= nft_redir_ipv4_eval,
+	.init		= nft_redir_init,
+	.dump		= nft_redir_dump,
+};
+
+static struct nft_expr_type nft_redir_ipv4_type __read_mostly = {
+	.family		= NFPROTO_IPV4,
+	.name		= "redir",
+	.ops		= &nft_redir_ipv4_ops,
+	.policy		= nft_redir_policy,
+	.maxattr	= NFTA_REDIR_MAX,
+	.owner		= THIS_MODULE,
+};
+
+static int __init nft_redir_ipv4_module_init(void)
+{
+	return nft_register_expr(&nft_redir_ipv4_type);
+}
+
+static void __exit nft_redir_ipv4_module_exit(void)
+{
+	nft_unregister_expr(&nft_redir_ipv4_type);
+}
+
+module_init(nft_redir_ipv4_module_init);
+module_exit(nft_redir_ipv4_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");
+MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "redir");
diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig
index 462eebb..0dbe5c7 100644
--- a/net/ipv6/netfilter/Kconfig
+++ b/net/ipv6/netfilter/Kconfig
@@ -97,6 +97,15 @@ config NFT_MASQ_IPV6
 	  This is the expression that provides IPv4 masquerading support for
 	  nf_tables.
 
+config NFT_REDIR_IPV6
+	tristate "IPv6 redirect support for nf_tables"
+	depends on NF_TABLES_IPV6
+	depends on NFT_REDIR
+	select NF_NAT_REDIRECT_IPV6
+	help
+	  This is the expression that provides IPv4 redirect support for
+	  nf_tables.
+
 endif # NF_NAT_IPV6
 
 config IP6_NF_IPTABLES
diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile
index 6c2baab..d2ac9f5 100644
--- a/net/ipv6/netfilter/Makefile
+++ b/net/ipv6/netfilter/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_NFT_CHAIN_ROUTE_IPV6) += nft_chain_route_ipv6.o
 obj-$(CONFIG_NFT_CHAIN_NAT_IPV6) += nft_chain_nat_ipv6.o
 obj-$(CONFIG_NFT_REJECT_IPV6) += nft_reject_ipv6.o
 obj-$(CONFIG_NFT_MASQ_IPV6) += nft_masq_ipv6.o
+obj-$(CONFIG_NFT_REDIR_IPV6) += nft_redir_ipv6.o
 
 # matches
 obj-$(CONFIG_IP6_NF_MATCH_AH) += ip6t_ah.o
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index f54b5f8..05d9475 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -505,6 +505,15 @@ config NFT_MASQ
 	  This option adds the "masquerade" expression that you can use
 	  to perform NAT in the masquerade flavour.
 
+config NFT_REDIR
+	depends on NF_TABLES
+	depends on NF_CONNTRACK
+	depends on NF_NAT
+	tristate "Netfilter nf_tables redirect support"
+	help
+	  This options adds the "redirect" expression that you can use
+	  to perform NAT in the redirect flavour.
+
 config NFT_NAT
 	depends on NF_TABLES
 	depends on NF_CONNTRACK
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index a9571be..f3eb468 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -88,6 +88,7 @@ obj-$(CONFIG_NFT_HASH)		+= nft_hash.o
 obj-$(CONFIG_NFT_COUNTER)	+= nft_counter.o
 obj-$(CONFIG_NFT_LOG)		+= nft_log.o
 obj-$(CONFIG_NFT_MASQ)		+= nft_masq.o
+obj-$(CONFIG_NFT_REDIR)		+= nft_redir.o
 
 # generic X tables 
 obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o
diff --git a/net/netfilter/nft_redir.c b/net/netfilter/nft_redir.c
new file mode 100644
index 0000000..424cbf1
--- /dev/null
+++ b/net/netfilter/nft_redir.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nft_redir.h>
+
+const struct nla_policy nft_redir_policy[NFTA_REDIR_MAX + 1] = {
+	[NFTA_REDIR_REG_PROTO_MIN]	= { .type = NLA_U32 },
+	[NFTA_REDIR_REG_PROTO_MAX]	= { .type = NLA_U32 },
+	[NFTA_REDIR_FLAGS]		= { .type = NLA_U16 },
+};
+EXPORT_SYMBOL_GPL(nft_redir_policy);
+
+int nft_redir_init(const struct nft_ctx *ctx,
+		   const struct nft_expr *expr,
+		   const struct nlattr * const tb[])
+{
+	struct nft_redir *priv = nft_expr_priv(expr);
+	int err;
+
+	if (tb[NFTA_REDIR_REG_PROTO_MIN]) {
+		priv->sreg_proto_min =
+			ntohl(nla_get_be32(tb[NFTA_REDIR_REG_PROTO_MIN]));
+		err = nft_validate_input_register(priv->sreg_proto_min);
+		if (err < 0)
+			return err;
+	}
+
+	if (tb[NFTA_REDIR_REG_PROTO_MAX]) {
+		priv->sreg_proto_max =
+			ntohl(nla_get_be32(tb[NFTA_REDIR_REG_PROTO_MAX]));
+		err = nft_validate_input_register(priv->sreg_proto_max);
+		if (err < 0)
+			return err;
+	} else {
+		priv->sreg_proto_max = priv->sreg_proto_min;
+	}
+
+	if (tb[NFTA_REDIR_FLAGS]) {
+		priv->flags = ntohl(nla_get_be16(tb[NFTA_REDIR_FLAGS]));
+		if (priv->flags & ~NF_NAT_RANGE_MASK)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nft_redir_init);
+
+int nft_redir_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+	const struct nft_redir *priv = nft_expr_priv(expr);
+
+	if (priv->sreg_proto_min) {
+		if (nla_put_be32(skb, NFTA_REDIR_REG_PROTO_MIN,
+				 htonl(priv->sreg_proto_min)))
+			goto nla_put_failure;
+		if (nla_put_be32(skb, NFTA_REDIR_REG_PROTO_MAX,
+				 htonl(priv->sreg_proto_max)))
+			goto nla_put_failure;
+	}
+
+	if (priv->flags != 0 &&
+	    nla_put_be16(skb, NFTA_REDIR_FLAGS, htonl(priv->flags)))
+			goto nla_put_failure;
+
+	return 0;
+
+nla_put_failure:
+	return -1;
+}
+EXPORT_SYMBOL_GPL(nft_redir_dump);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");

Re: [nf_tables PATCH v2 3/3] netfilter: nf_tables: add new expression nft_redir

[Pablo Neira Ayuso]

On Thu, Oct 16, 2014 at 12:25:08PM +0200, Arturo Borrero Gonzalez wrote:
> This new expression provides NAT in the redirect flavour, which is to
> redirect packets to local machine.

Please, apply this:

http://patchwork.ozlabs.org/patch/399263/

before your patches, and add the missing code to validate that the
redirect can be only used from the nat chain type.

Thanks.

Re: [nf_tables PATCH v2 2/3] netfilter: refactor NAT redirect IPv6 code to use it from nf_tables

[Pablo Neira Ayuso]

On Thu, Oct 16, 2014 at 12:23:57PM +0200, Arturo Borrero Gonzalez wrote:
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
> diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
> index a0716a3..f54b5f8 100644
> --- a/net/netfilter/Kconfig
> +++ b/net/netfilter/Kconfig
> @@ -836,6 +836,7 @@ config NETFILTER_XT_TARGET_REDIRECT
>  	tristate "REDIRECT target support"
>  	depends on NF_NAT
>  	select NF_NAT_REDIRECT_IPV4
> +	select NF_NAT_REDIRECT_IPV6

        select NF_NAT_REDIRECT_IPV6 if IP6_NF_IPTABLES

Re: [nf_tables PATCH v2 3/3] netfilter: nf_tables: add new expression nft_redir

[Pablo Neira Ayuso]

On Thu, Oct 16, 2014 at 12:25:08PM +0200, Arturo Borrero Gonzalez wrote:
> diff --git a/net/netfilter/nft_redir.c b/net/netfilter/nft_redir.c
> new file mode 100644
> index 0000000..424cbf1
> --- /dev/null
> +++ b/net/netfilter/nft_redir.c
> @@ -0,0 +1,86 @@
> +/*
> + * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
> + *
> + * 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/kernel.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/netlink.h>
> +#include <linux/netfilter.h>
> +#include <linux/netfilter/nf_tables.h>
> +#include <net/netfilter/nf_nat.h>
> +#include <net/netfilter/nf_tables.h>
> +#include <net/netfilter/nft_redir.h>
> +
> +const struct nla_policy nft_redir_policy[NFTA_REDIR_MAX + 1] = {
> +	[NFTA_REDIR_REG_PROTO_MIN]	= { .type = NLA_U32 },
> +	[NFTA_REDIR_REG_PROTO_MAX]	= { .type = NLA_U32 },
> +	[NFTA_REDIR_FLAGS]		= { .type = NLA_U16 },
> +};
> +EXPORT_SYMBOL_GPL(nft_redir_policy);
> +
> +int nft_redir_init(const struct nft_ctx *ctx,
> +		   const struct nft_expr *expr,
> +		   const struct nlattr * const tb[])
> +{
> +	struct nft_redir *priv = nft_expr_priv(expr);
> +	int err;
> +
> +	if (tb[NFTA_REDIR_REG_PROTO_MIN]) {
> +		priv->sreg_proto_min =
> +			ntohl(nla_get_be32(tb[NFTA_REDIR_REG_PROTO_MIN]));
> +		err = nft_validate_input_register(priv->sreg_proto_min);
> +		if (err < 0)
> +			return err;


Add the max handling here:

                if (tb[NFTA_REDIR_REG_PROTO_MAX]) {
                        ...
                }
> +	}

The idea is that NFTA_REDIR_REG_PROTO_MAX is only interpreted if
NFTA_REDIR_REG_PROTO_MIN is specified. I'll send a similar patch for
nft_nat.

Thanks Arturo.

Re: [nf_tables PATCH v2 1/3] netfilter: refactor NAT redirect IPv4 to use it from nf_tables

[Pablo Neira Ayuso]

On Thu, Oct 16, 2014 at 12:23:29PM +0200, Arturo Borrero Gonzalez wrote:
> This patch refactors the IPv4 code so it can be usable both from xt and
> nf_tables.
> 
> A similar patch follows-up to handle IPv6.

Applied, thanks.