net/netfilter/nft_nat.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
  * Copyright (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
  * Copyright (c) 2012 Intel Corporation
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/skbuff.h>
 #include <linux/ip.h>
 #include <linux/string.h>
 #include <linux/netlink.h>
 #include <linux/netfilter.h>
 #include <linux/netfilter_ipv4.h>
 #include <linux/netfilter/nfnetlink.h>
 #include <linux/netfilter/nf_tables.h>
 #include <net/netfilter/nf_conntrack.h>
 #include <net/netfilter/nf_nat.h>
 #include <net/netfilter/nf_tables.h>
 #include <net/ip.h>

 struct nft_nat {
 	enum nft_registers      sreg_addr_min:8;
 	enum nft_registers      sreg_addr_max:8;
 	enum nft_registers      sreg_proto_min:8;
 	enum nft_registers      sreg_proto_max:8;
 	enum nf_nat_manip_type  type:8;
 	u8			family;
 	u16			flags;
 };

 static void nft_nat_setup_addr(struct nf_nat_range2 *range,
 			       const struct nft_regs *regs,
 			       const struct nft_nat *priv)
 {
 	switch (priv->family) {
 	case AF_INET:
 		range->min_addr.ip = (__force __be32)
 				regs->data[priv->sreg_addr_min];
 		range->max_addr.ip = (__force __be32)
 				regs->data[priv->sreg_addr_max];
 		break;
 	case AF_INET6:
 		memcpy(range->min_addr.ip6, &regs->data[priv->sreg_addr_min],
 		       sizeof(range->min_addr.ip6));
 		memcpy(range->max_addr.ip6, &regs->data[priv->sreg_addr_max],
 		       sizeof(range->max_addr.ip6));
 		break;
 	}
 }

 static void nft_nat_setup_proto(struct nf_nat_range2 *range,
 				const struct nft_regs *regs,
 				const struct nft_nat *priv)
 {
 	range->min_proto.all = (__force __be16)
 		nft_reg_load16(&regs->data[priv->sreg_proto_min]);
 	range->max_proto.all = (__force __be16)
 		nft_reg_load16(&regs->data[priv->sreg_proto_max]);
 }

 static void nft_nat_setup_netmap(struct nf_nat_range2 *range,
 				 const struct nft_pktinfo *pkt,
 				 const struct nft_nat *priv)
 {
 	struct sk_buff *skb = pkt->skb;
 	union nf_inet_addr new_addr;
 	__be32 netmask;
 	int i, len = 0;

 	switch (priv->type) {
 	case NFT_NAT_SNAT:
 		if (nft_pf(pkt) == NFPROTO_IPV4) {
 			new_addr.ip = ip_hdr(skb)->saddr;
 			len = sizeof(struct in_addr);
 		} else {
 			new_addr.in6 = ipv6_hdr(skb)->saddr;
 			len = sizeof(struct in6_addr);
 		}
 		break;
 	case NFT_NAT_DNAT:
 		if (nft_pf(pkt) == NFPROTO_IPV4) {
 			new_addr.ip = ip_hdr(skb)->daddr;
 			len = sizeof(struct in_addr);
 		} else {
 			new_addr.in6 = ipv6_hdr(skb)->daddr;
 			len = sizeof(struct in6_addr);
 		}
 		break;
 	}

 	for (i = 0; i < len / sizeof(__be32); i++) {
 		netmask = ~(range->min_addr.ip6[i] ^ range->max_addr.ip6[i]);
 		new_addr.ip6[i] &= ~netmask;
 		new_addr.ip6[i] |= range->min_addr.ip6[i] & netmask;
 	}

 	range->min_addr = new_addr;
 	range->max_addr = new_addr;
 }

 static void nft_nat_eval(const struct nft_expr *expr,
 			 struct nft_regs *regs,
 			 const struct nft_pktinfo *pkt)
 {
 	const struct nft_nat *priv = nft_expr_priv(expr);
 	enum ip_conntrack_info ctinfo;
 	struct nf_conn *ct = nf_ct_get(pkt->skb, &ctinfo);
 	struct nf_nat_range2 range;

 	memset(&range, 0, sizeof(range));

 	if (priv->sreg_addr_min) {
 		nft_nat_setup_addr(&range, regs, priv);
 		if (priv->flags & NF_NAT_RANGE_NETMAP)
 			nft_nat_setup_netmap(&range, pkt, priv);
 	}

 	if (priv->sreg_proto_min)
 		nft_nat_setup_proto(&range, regs, priv);

 	range.flags = priv->flags;

 	regs->verdict.code = nf_nat_setup_info(ct, &range, priv->type);
 }

 static const struct nla_policy nft_nat_policy[NFTA_NAT_MAX + 1] = {
 	[NFTA_NAT_TYPE]		 = { .type = NLA_U32 },
 	[NFTA_NAT_FAMILY]	 = { .type = NLA_U32 },
 	[NFTA_NAT_REG_ADDR_MIN]	 = { .type = NLA_U32 },
 	[NFTA_NAT_REG_ADDR_MAX]	 = { .type = NLA_U32 },
 	[NFTA_NAT_REG_PROTO_MIN] = { .type = NLA_U32 },
 	[NFTA_NAT_REG_PROTO_MAX] = { .type = NLA_U32 },
 	[NFTA_NAT_FLAGS]	 = { .type = NLA_U32 },
 };

 static int nft_nat_validate(const struct nft_ctx *ctx,
 			    const struct nft_expr *expr,
 			    const struct nft_data **data)
 {
 	struct nft_nat *priv = nft_expr_priv(expr);
 	int err;

 	err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
 	if (err < 0)
 		return err;

 	switch (priv->type) {
 	case NFT_NAT_SNAT:
 		err = nft_chain_validate_hooks(ctx->chain,
 					       (1 << NF_INET_POST_ROUTING) |
 					       (1 << NF_INET_LOCAL_IN));
 		break;
 	case NFT_NAT_DNAT:
 		err = nft_chain_validate_hooks(ctx->chain,
 					       (1 << NF_INET_PRE_ROUTING) |
 					       (1 << NF_INET_LOCAL_OUT));
 		break;
 	}

 	return err;
 }

 static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
 			const struct nlattr * const tb[])
 {
 	struct nft_nat *priv = nft_expr_priv(expr);
 	unsigned int alen, plen;
 	u32 family;
 	int err;

 	if (tb[NFTA_NAT_TYPE] == NULL ||
 	    (tb[NFTA_NAT_REG_ADDR_MIN] == NULL &&
 	     tb[NFTA_NAT_REG_PROTO_MIN] == NULL))
 		return -EINVAL;

 	switch (ntohl(nla_get_be32(tb[NFTA_NAT_TYPE]))) {
 	case NFT_NAT_SNAT:
 		priv->type = NF_NAT_MANIP_SRC;
 		break;
 	case NFT_NAT_DNAT:
 		priv->type = NF_NAT_MANIP_DST;
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}

 	if (tb[NFTA_NAT_FAMILY] == NULL)
 		return -EINVAL;

 	family = ntohl(nla_get_be32(tb[NFTA_NAT_FAMILY]));
 	if (ctx->family != NFPROTO_INET && ctx->family != family)
 		return -EOPNOTSUPP;

 	switch (family) {
 	case NFPROTO_IPV4:
 		alen = sizeof_field(struct nf_nat_range, min_addr.ip);
 		break;
 	case NFPROTO_IPV6:
 		alen = sizeof_field(struct nf_nat_range, min_addr.ip6);
 		break;
 	default:
 		return -EAFNOSUPPORT;
 	}
 	priv->family = family;

 	if (tb[NFTA_NAT_REG_ADDR_MIN]) {
 		priv->sreg_addr_min =
 			nft_parse_register(tb[NFTA_NAT_REG_ADDR_MIN]);
 		err = nft_validate_register_load(priv->sreg_addr_min, alen);
 		if (err < 0)
 			return err;

 		if (tb[NFTA_NAT_REG_ADDR_MAX]) {
 			priv->sreg_addr_max =
 				nft_parse_register(tb[NFTA_NAT_REG_ADDR_MAX]);

 			err = nft_validate_register_load(priv->sreg_addr_max,
 							 alen);
 			if (err < 0)
 				return err;
 		} else {
 			priv->sreg_addr_max = priv->sreg_addr_min;
 		}

 		priv->flags |= NF_NAT_RANGE_MAP_IPS;
 	}

 	plen = sizeof_field(struct nf_nat_range, min_addr.all);
 	if (tb[NFTA_NAT_REG_PROTO_MIN]) {
 		priv->sreg_proto_min =
 			nft_parse_register(tb[NFTA_NAT_REG_PROTO_MIN]);

 		err = nft_validate_register_load(priv->sreg_proto_min, plen);
 		if (err < 0)
 			return err;

 		if (tb[NFTA_NAT_REG_PROTO_MAX]) {
 			priv->sreg_proto_max =
 				nft_parse_register(tb[NFTA_NAT_REG_PROTO_MAX]);

 			err = nft_validate_register_load(priv->sreg_proto_max,
 							 plen);
 			if (err < 0)
 				return err;
 		} else {
 			priv->sreg_proto_max = priv->sreg_proto_min;
 		}

 		priv->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
 	}

 	if (tb[NFTA_NAT_FLAGS]) {
 		priv->flags |= ntohl(nla_get_be32(tb[NFTA_NAT_FLAGS]));
 		if (priv->flags & ~NF_NAT_RANGE_MASK)
 			return -EOPNOTSUPP;
 	}

 	return nf_ct_netns_get(ctx->net, family);
 }

 static int nft_nat_dump(struct sk_buff *skb, const struct nft_expr *expr)
 {
 	const struct nft_nat *priv = nft_expr_priv(expr);

 	switch (priv->type) {
 	case NF_NAT_MANIP_SRC:
 		if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_SNAT)))
 			goto nla_put_failure;
 		break;
 	case NF_NAT_MANIP_DST:
 		if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_DNAT)))
 			goto nla_put_failure;
 		break;
 	}

 	if (nla_put_be32(skb, NFTA_NAT_FAMILY, htonl(priv->family)))
 		goto nla_put_failure;

 	if (priv->sreg_addr_min) {
 		if (nft_dump_register(skb, NFTA_NAT_REG_ADDR_MIN,
 				      priv->sreg_addr_min) ||
 		    nft_dump_register(skb, NFTA_NAT_REG_ADDR_MAX,
 				      priv->sreg_addr_max))
 			goto nla_put_failure;
 	}

 	if (priv->sreg_proto_min) {
 		if (nft_dump_register(skb, NFTA_NAT_REG_PROTO_MIN,
 				      priv->sreg_proto_min) ||
 		    nft_dump_register(skb, NFTA_NAT_REG_PROTO_MAX,
 				      priv->sreg_proto_max))
 			goto nla_put_failure;
 	}

 	if (priv->flags != 0) {
 		if (nla_put_be32(skb, NFTA_NAT_FLAGS, htonl(priv->flags)))
 			goto nla_put_failure;
 	}

 	return 0;

 nla_put_failure:
 	return -1;
 }

 static void
 nft_nat_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
 {
 	const struct nft_nat *priv = nft_expr_priv(expr);

 	nf_ct_netns_put(ctx->net, priv->family);
 }

 static struct nft_expr_type nft_nat_type;
 static const struct nft_expr_ops nft_nat_ops = {
 	.type           = &nft_nat_type,
 	.size           = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
 	.eval           = nft_nat_eval,
 	.init           = nft_nat_init,
 	.destroy        = nft_nat_destroy,
 	.dump           = nft_nat_dump,
 	.validate	= nft_nat_validate,
 };

 static struct nft_expr_type nft_nat_type __read_mostly = {
 	.name           = "nat",
 	.ops            = &nft_nat_ops,
 	.policy         = nft_nat_policy,
 	.maxattr        = NFTA_NAT_MAX,
 	.owner          = THIS_MODULE,
 };

 #ifdef CONFIG_NF_TABLES_INET
 static void nft_nat_inet_eval(const struct nft_expr *expr,
 			      struct nft_regs *regs,
 			      const struct nft_pktinfo *pkt)
 {
 	const struct nft_nat *priv = nft_expr_priv(expr);

 	if (priv->family == nft_pf(pkt))
 		nft_nat_eval(expr, regs, pkt);
 }

 static const struct nft_expr_ops nft_nat_inet_ops = {
 	.type           = &nft_nat_type,
 	.size           = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
 	.eval           = nft_nat_inet_eval,
 	.init           = nft_nat_init,
 	.destroy        = nft_nat_destroy,
 	.dump           = nft_nat_dump,
 	.validate	= nft_nat_validate,
 };

 static struct nft_expr_type nft_inet_nat_type __read_mostly = {
 	.name           = "nat",
 	.family		= NFPROTO_INET,
 	.ops            = &nft_nat_inet_ops,
 	.policy         = nft_nat_policy,
 	.maxattr        = NFTA_NAT_MAX,
 	.owner          = THIS_MODULE,
 };

 static int nft_nat_inet_module_init(void)
 {
 	return nft_register_expr(&nft_inet_nat_type);
 }

 static void nft_nat_inet_module_exit(void)
 {
 	nft_unregister_expr(&nft_inet_nat_type);
 }
 #else
 static int nft_nat_inet_module_init(void) { return 0; }
 static void nft_nat_inet_module_exit(void) { }
 #endif

 static int __init nft_nat_module_init(void)
 {
 	int ret = nft_nat_inet_module_init();

 	if (ret)
 		return ret;

 	ret = nft_register_expr(&nft_nat_type);
 	if (ret)
 		nft_nat_inet_module_exit();

 	return ret;
 }

 static void __exit nft_nat_module_exit(void)
 {
 	nft_nat_inet_module_exit();
 	nft_unregister_expr(&nft_nat_type);
 }

 module_init(nft_nat_module_init);
 module_exit(nft_nat_module_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>");
 MODULE_ALIAS_NFT_EXPR("nat");
 MODULE_DESCRIPTION("Network Address Translation support");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
	* Copyright (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
	* Copyright (c) 2012 Intel Corporation
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/skbuff.h>
	#include <linux/ip.h>
	#include <linux/string.h>
	#include <linux/netlink.h>
	#include <linux/netfilter.h>
	#include <linux/netfilter_ipv4.h>
	#include <linux/netfilter/nfnetlink.h>
	#include <linux/netfilter/nf_tables.h>
	#include <net/netfilter/nf_conntrack.h>
	#include <net/netfilter/nf_nat.h>
	#include <net/netfilter/nf_tables.h>
	#include <net/ip.h>

	struct nft_nat {
	enum nft_registers sreg_addr_min:8;
	enum nft_registers sreg_addr_max:8;
	enum nft_registers sreg_proto_min:8;
	enum nft_registers sreg_proto_max:8;
	enum nf_nat_manip_type type:8;
	u8 family;
	u16 flags;
	};

	static void nft_nat_setup_addr(struct nf_nat_range2 *range,
	const struct nft_regs *regs,
	const struct nft_nat *priv)
	{
	switch (priv->family) {
	case AF_INET:
	range->min_addr.ip = (__force __be32)
	regs->data[priv->sreg_addr_min];
	range->max_addr.ip = (__force __be32)
	regs->data[priv->sreg_addr_max];
	break;
	case AF_INET6:
	memcpy(range->min_addr.ip6, &regs->data[priv->sreg_addr_min],
	sizeof(range->min_addr.ip6));
	memcpy(range->max_addr.ip6, &regs->data[priv->sreg_addr_max],
	sizeof(range->max_addr.ip6));
	break;
	}
	}

	static void nft_nat_setup_proto(struct nf_nat_range2 *range,
	const struct nft_regs *regs,
	const struct nft_nat *priv)
	{
	range->min_proto.all = (__force __be16)
	nft_reg_load16(&regs->data[priv->sreg_proto_min]);
	range->max_proto.all = (__force __be16)
	nft_reg_load16(&regs->data[priv->sreg_proto_max]);
	}

	static void nft_nat_setup_netmap(struct nf_nat_range2 *range,
	const struct nft_pktinfo *pkt,
	const struct nft_nat *priv)
	{
	struct sk_buff *skb = pkt->skb;
	union nf_inet_addr new_addr;
	__be32 netmask;
	int i, len = 0;

	switch (priv->type) {
	case NFT_NAT_SNAT:
	if (nft_pf(pkt) == NFPROTO_IPV4) {
	new_addr.ip = ip_hdr(skb)->saddr;
	len = sizeof(struct in_addr);
	} else {
	new_addr.in6 = ipv6_hdr(skb)->saddr;
	len = sizeof(struct in6_addr);
	}
	break;
	case NFT_NAT_DNAT:
	if (nft_pf(pkt) == NFPROTO_IPV4) {
	new_addr.ip = ip_hdr(skb)->daddr;
	len = sizeof(struct in_addr);
	} else {
	new_addr.in6 = ipv6_hdr(skb)->daddr;
	len = sizeof(struct in6_addr);
	}
	break;
	}

	for (i = 0; i < len / sizeof(__be32); i++) {
	netmask = ~(range->min_addr.ip6[i] ^ range->max_addr.ip6[i]);
	new_addr.ip6[i] &= ~netmask;
	new_addr.ip6[i] \|= range->min_addr.ip6[i] & netmask;
	}

	range->min_addr = new_addr;
	range->max_addr = new_addr;
	}

	static void nft_nat_eval(const struct nft_expr *expr,
	struct nft_regs *regs,
	const struct nft_pktinfo *pkt)
	{
	const struct nft_nat *priv = nft_expr_priv(expr);
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct = nf_ct_get(pkt->skb, &ctinfo);
	struct nf_nat_range2 range;

	memset(&range, 0, sizeof(range));

	if (priv->sreg_addr_min) {
	nft_nat_setup_addr(&range, regs, priv);
	if (priv->flags & NF_NAT_RANGE_NETMAP)
	nft_nat_setup_netmap(&range, pkt, priv);
	}

	if (priv->sreg_proto_min)
	nft_nat_setup_proto(&range, regs, priv);

	range.flags = priv->flags;

	regs->verdict.code = nf_nat_setup_info(ct, &range, priv->type);
	}

	static const struct nla_policy nft_nat_policy[NFTA_NAT_MAX + 1] = {
	[NFTA_NAT_TYPE] = { .type = NLA_U32 },
	[NFTA_NAT_FAMILY] = { .type = NLA_U32 },
	[NFTA_NAT_REG_ADDR_MIN] = { .type = NLA_U32 },
	[NFTA_NAT_REG_ADDR_MAX] = { .type = NLA_U32 },
	[NFTA_NAT_REG_PROTO_MIN] = { .type = NLA_U32 },
	[NFTA_NAT_REG_PROTO_MAX] = { .type = NLA_U32 },
	[NFTA_NAT_FLAGS] = { .type = NLA_U32 },
	};

	static int nft_nat_validate(const struct nft_ctx *ctx,
	const struct nft_expr *expr,
	const struct nft_data **data)
	{
	struct nft_nat *priv = nft_expr_priv(expr);
	int err;

	err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
	if (err < 0)
	return err;

	switch (priv->type) {
	case NFT_NAT_SNAT:
	err = nft_chain_validate_hooks(ctx->chain,
	(1 << NF_INET_POST_ROUTING) \|
	(1 << NF_INET_LOCAL_IN));
	break;
	case NFT_NAT_DNAT:
	err = nft_chain_validate_hooks(ctx->chain,
	(1 << NF_INET_PRE_ROUTING) \|
	(1 << NF_INET_LOCAL_OUT));
	break;
	}

	return err;
	}

	static int nft_nat_init(const struct nft_ctx ctx, const struct nft_expr expr,
	const struct nlattr * const tb[])
	{
	struct nft_nat *priv = nft_expr_priv(expr);
	unsigned int alen, plen;
	u32 family;
	int err;

	if (tb[NFTA_NAT_TYPE] == NULL \|\|
	(tb[NFTA_NAT_REG_ADDR_MIN] == NULL &&
	tb[NFTA_NAT_REG_PROTO_MIN] == NULL))
	return -EINVAL;

	switch (ntohl(nla_get_be32(tb[NFTA_NAT_TYPE]))) {
	case NFT_NAT_SNAT:
	priv->type = NF_NAT_MANIP_SRC;
	break;
	case NFT_NAT_DNAT:
	priv->type = NF_NAT_MANIP_DST;
	break;
	default:
	return -EOPNOTSUPP;
	}

	if (tb[NFTA_NAT_FAMILY] == NULL)
	return -EINVAL;

	family = ntohl(nla_get_be32(tb[NFTA_NAT_FAMILY]));
	if (ctx->family != NFPROTO_INET && ctx->family != family)
	return -EOPNOTSUPP;

	switch (family) {
	case NFPROTO_IPV4:
	alen = sizeof_field(struct nf_nat_range, min_addr.ip);
	break;
	case NFPROTO_IPV6:
	alen = sizeof_field(struct nf_nat_range, min_addr.ip6);
	break;
	default:
	return -EAFNOSUPPORT;
	}
	priv->family = family;

	if (tb[NFTA_NAT_REG_ADDR_MIN]) {
	priv->sreg_addr_min =
	nft_parse_register(tb[NFTA_NAT_REG_ADDR_MIN]);
	err = nft_validate_register_load(priv->sreg_addr_min, alen);
	if (err < 0)
	return err;

	if (tb[NFTA_NAT_REG_ADDR_MAX]) {
	priv->sreg_addr_max =
	nft_parse_register(tb[NFTA_NAT_REG_ADDR_MAX]);

	err = nft_validate_register_load(priv->sreg_addr_max,
	alen);
	if (err < 0)
	return err;
	} else {
	priv->sreg_addr_max = priv->sreg_addr_min;
	}

	priv->flags \|= NF_NAT_RANGE_MAP_IPS;
	}

	plen = sizeof_field(struct nf_nat_range, min_addr.all);
	if (tb[NFTA_NAT_REG_PROTO_MIN]) {
	priv->sreg_proto_min =
	nft_parse_register(tb[NFTA_NAT_REG_PROTO_MIN]);

	err = nft_validate_register_load(priv->sreg_proto_min, plen);
	if (err < 0)
	return err;

	if (tb[NFTA_NAT_REG_PROTO_MAX]) {
	priv->sreg_proto_max =
	nft_parse_register(tb[NFTA_NAT_REG_PROTO_MAX]);

	err = nft_validate_register_load(priv->sreg_proto_max,
	plen);
	if (err < 0)
	return err;
	} else {
	priv->sreg_proto_max = priv->sreg_proto_min;
	}

	priv->flags \|= NF_NAT_RANGE_PROTO_SPECIFIED;
	}

	if (tb[NFTA_NAT_FLAGS]) {
	priv->flags \|= ntohl(nla_get_be32(tb[NFTA_NAT_FLAGS]));
	if (priv->flags & ~NF_NAT_RANGE_MASK)
	return -EOPNOTSUPP;
	}

	return nf_ct_netns_get(ctx->net, family);
	}

	static int nft_nat_dump(struct sk_buff skb, const struct nft_expr expr)
	{
	const struct nft_nat *priv = nft_expr_priv(expr);

	switch (priv->type) {
	case NF_NAT_MANIP_SRC:
	if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_SNAT)))
	goto nla_put_failure;
	break;
	case NF_NAT_MANIP_DST:
	if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_DNAT)))
	goto nla_put_failure;
	break;
	}

	if (nla_put_be32(skb, NFTA_NAT_FAMILY, htonl(priv->family)))
	goto nla_put_failure;

	if (priv->sreg_addr_min) {
	if (nft_dump_register(skb, NFTA_NAT_REG_ADDR_MIN,
	priv->sreg_addr_min) \|\|
	nft_dump_register(skb, NFTA_NAT_REG_ADDR_MAX,
	priv->sreg_addr_max))
	goto nla_put_failure;
	}

	if (priv->sreg_proto_min) {
	if (nft_dump_register(skb, NFTA_NAT_REG_PROTO_MIN,
	priv->sreg_proto_min) \|\|
	nft_dump_register(skb, NFTA_NAT_REG_PROTO_MAX,
	priv->sreg_proto_max))
	goto nla_put_failure;
	}

	if (priv->flags != 0) {
	if (nla_put_be32(skb, NFTA_NAT_FLAGS, htonl(priv->flags)))
	goto nla_put_failure;
	}

	return 0;

	nla_put_failure:
	return -1;
	}

	static void
	nft_nat_destroy(const struct nft_ctx ctx, const struct nft_expr expr)
	{
	const struct nft_nat *priv = nft_expr_priv(expr);

	nf_ct_netns_put(ctx->net, priv->family);
	}

	static struct nft_expr_type nft_nat_type;
	static const struct nft_expr_ops nft_nat_ops = {
	.type = &nft_nat_type,
	.size = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
	.eval = nft_nat_eval,
	.init = nft_nat_init,
	.destroy = nft_nat_destroy,
	.dump = nft_nat_dump,
	.validate = nft_nat_validate,
	};

	static struct nft_expr_type nft_nat_type __read_mostly = {
	.name = "nat",
	.ops = &nft_nat_ops,
	.policy = nft_nat_policy,
	.maxattr = NFTA_NAT_MAX,
	.owner = THIS_MODULE,
	};

	#ifdef CONFIG_NF_TABLES_INET
	static void nft_nat_inet_eval(const struct nft_expr *expr,
	struct nft_regs *regs,
	const struct nft_pktinfo *pkt)
	{
	const struct nft_nat *priv = nft_expr_priv(expr);

	if (priv->family == nft_pf(pkt))
	nft_nat_eval(expr, regs, pkt);
	}

	static const struct nft_expr_ops nft_nat_inet_ops = {
	.type = &nft_nat_type,
	.size = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
	.eval = nft_nat_inet_eval,
	.init = nft_nat_init,
	.destroy = nft_nat_destroy,
	.dump = nft_nat_dump,
	.validate = nft_nat_validate,
	};

	static struct nft_expr_type nft_inet_nat_type __read_mostly = {
	.name = "nat",
	.family = NFPROTO_INET,
	.ops = &nft_nat_inet_ops,
	.policy = nft_nat_policy,
	.maxattr = NFTA_NAT_MAX,
	.owner = THIS_MODULE,
	};

	static int nft_nat_inet_module_init(void)
	{
	return nft_register_expr(&nft_inet_nat_type);
	}

	static void nft_nat_inet_module_exit(void)
	{
	nft_unregister_expr(&nft_inet_nat_type);
	}
	#else
	static int nft_nat_inet_module_init(void) { return 0; }
	static void nft_nat_inet_module_exit(void) { }
	#endif

	static int __init nft_nat_module_init(void)
	{
	int ret = nft_nat_inet_module_init();

	if (ret)
	return ret;

	ret = nft_register_expr(&nft_nat_type);
	if (ret)
	nft_nat_inet_module_exit();

	return ret;
	}

	static void __exit nft_nat_module_exit(void)
	{
	nft_nat_inet_module_exit();
	nft_unregister_expr(&nft_nat_type);
	}

	module_init(nft_nat_module_init);
	module_exit(nft_nat_module_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>");
	MODULE_ALIAS_NFT_EXPR("nat");
	MODULE_DESCRIPTION("Network Address Translation support");