[mirror_ubuntu-artful-kernel.git] / net / netfilter / nft_nat.c

/*
 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
 * Copyright (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
 * Copyright (c) 2012 Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 */

#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_nat_core.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_nat_l3proto.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_eval(const struct nft_expr *expr,
			 struct nft_data data[NFT_REG_MAX + 1],
			 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_range range;

	memset(&range, 0, sizeof(range));
	if (priv->sreg_addr_min) {
		if (priv->family == AF_INET) {
			range.min_addr.ip = (__force __be32)
					data[priv->sreg_addr_min].data[0];
			range.max_addr.ip = (__force __be32)
					data[priv->sreg_addr_max].data[0];

		} else {
			memcpy(range.min_addr.ip6,
			       data[priv->sreg_addr_min].data,
			       sizeof(struct nft_data));
			memcpy(range.max_addr.ip6,
			       data[priv->sreg_addr_max].data,
			       sizeof(struct nft_data));
		}
		range.flags |= NF_NAT_RANGE_MAP_IPS;
	}

	if (priv->sreg_proto_min) {
		range.min_proto.all =
			*(__be16 *)&data[priv->sreg_proto_min].data[0];
		range.max_proto.all =
			*(__be16 *)&data[priv->sreg_proto_max].data[0];
		range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
	}

	range.flags |= priv->flags;

	data[NFT_REG_VERDICT].verdict =
		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);
	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 -EINVAL;
	}

	err = nft_nat_validate(ctx, expr, NULL);
	if (err < 0)
		return err;

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

	family = ntohl(nla_get_be32(tb[NFTA_NAT_FAMILY]));
	if (family != AF_INET && family != AF_INET6)
		return -EAFNOSUPPORT;
	if (family != ctx->afi->family)
		return -EOPNOTSUPP;
	priv->family = family;

	if (tb[NFTA_NAT_REG_ADDR_MIN]) {
		priv->sreg_addr_min =
			ntohl(nla_get_be32(tb[NFTA_NAT_REG_ADDR_MIN]));

		err = nft_validate_input_register(priv->sreg_addr_min);
		if (err < 0)
			return err;

		if (tb[NFTA_NAT_REG_ADDR_MAX]) {
			priv->sreg_addr_max =
				ntohl(nla_get_be32(tb[NFTA_NAT_REG_ADDR_MAX]));

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

	if (tb[NFTA_NAT_REG_PROTO_MIN]) {
		priv->sreg_proto_min =
			ntohl(nla_get_be32(tb[NFTA_NAT_REG_PROTO_MIN]));

		err = nft_validate_input_register(priv->sreg_proto_min);
		if (err < 0)
			return err;

		if (tb[NFTA_NAT_REG_PROTO_MAX]) {
			priv->sreg_proto_max =
				ntohl(nla_get_be32(tb[NFTA_NAT_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_NAT_FLAGS]) {
		priv->flags = ntohl(nla_get_be32(tb[NFTA_NAT_FLAGS]));
		if (priv->flags & ~NF_NAT_RANGE_MASK)
			return -EINVAL;
	}

	return 0;
}

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 (nla_put_be32(skb, NFTA_NAT_REG_ADDR_MIN,
				 htonl(priv->sreg_addr_min)) ||
		    nla_put_be32(skb, NFTA_NAT_REG_ADDR_MAX,
				 htonl(priv->sreg_addr_max)))
			goto nla_put_failure;
	}

	if (priv->sreg_proto_min) {
		if (nla_put_be32(skb, NFTA_NAT_REG_PROTO_MIN,
				 htonl(priv->sreg_proto_min)) ||
		    nla_put_be32(skb, NFTA_NAT_REG_PROTO_MAX,
				 htonl(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 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,
	.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,
};

static int __init nft_nat_module_init(void)
{
	return nft_register_expr(&nft_nat_type);
}

static void __exit nft_nat_module_exit(void)
{
	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");
Commit	Line	Data
eb31628e TB	1	/*
	2	* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
	3	* Copyright (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
	4	* Copyright (c) 2012 Intel Corporation
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms and conditions of the GNU General Public License,
	8	* version 2, as published by the Free Software Foundation.
	9	*
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/init.h>
	14	#include <linux/skbuff.h>
	15	#include <linux/ip.h>
	16	#include <linux/string.h>
	17	#include <linux/netlink.h>
	18	#include <linux/netfilter.h>
	19	#include <linux/netfilter_ipv4.h>
	20	#include <linux/netfilter/nfnetlink.h>
	21	#include <linux/netfilter/nf_tables.h>
	22	#include <net/netfilter/nf_conntrack.h>
	23	#include <net/netfilter/nf_nat.h>
	24	#include <net/netfilter/nf_nat_core.h>
	25	#include <net/netfilter/nf_tables.h>
	26	#include <net/netfilter/nf_nat_l3proto.h>
	27	#include <net/ip.h>
	28
	29	struct nft_nat {
	30	enum nft_registers sreg_addr_min:8;
	31	enum nft_registers sreg_addr_max:8;
	32	enum nft_registers sreg_proto_min:8;
	33	enum nft_registers sreg_proto_max:8;
a4c2e8be PM	34	enum nf_nat_manip_type type:8;
a4c2e8be PM	35	u8 family;
e42eff8a	36	u16 flags;
eb31628e TB	37	};
	38
	39	static void nft_nat_eval(const struct nft_expr *expr,
	40	struct nft_data data[NFT_REG_MAX + 1],
	41	const struct nft_pktinfo *pkt)
	42	{
	43	const struct nft_nat *priv = nft_expr_priv(expr);
	44	enum ip_conntrack_info ctinfo;
	45	struct nf_conn *ct = nf_ct_get(pkt->skb, &ctinfo);
	46	struct nf_nat_range range;
	47
	48	memset(&range, 0, sizeof(range));
	49	if (priv->sreg_addr_min) {
	50	if (priv->family == AF_INET) {
98c37b6b TB	51	range.min_addr.ip = (__force __be32)
	52	data[priv->sreg_addr_min].data[0];
	53	range.max_addr.ip = (__force __be32)
	54	data[priv->sreg_addr_max].data[0];
eb31628e TB	55
	56	} else {
	57	memcpy(range.min_addr.ip6,
	58	data[priv->sreg_addr_min].data,
	59	sizeof(struct nft_data));
	60	memcpy(range.max_addr.ip6,
	61	data[priv->sreg_addr_max].data,
	62	sizeof(struct nft_data));
	63	}
	64	range.flags \|= NF_NAT_RANGE_MAP_IPS;
	65	}
	66
	67	if (priv->sreg_proto_min) {
7b5bca46	68	range.min_proto.all =
	69	(__be16 )&data[priv->sreg_proto_min].data[0];
	70	range.max_proto.all =
	71	(__be16 )&data[priv->sreg_proto_max].data[0];
eb31628e TB	72	range.flags \|= NF_NAT_RANGE_PROTO_SPECIFIED;
	73	}
	74
e42eff8a AB	75	range.flags \|= priv->flags;
e42eff8a AB	76
eb31628e TB	77	data[NFT_REG_VERDICT].verdict =
	78	nf_nat_setup_info(ct, &range, priv->type);
	79	}
	80
	81	static const struct nla_policy nft_nat_policy[NFTA_NAT_MAX + 1] = {
	82	[NFTA_NAT_TYPE] = { .type = NLA_U32 },
	83	[NFTA_NAT_FAMILY] = { .type = NLA_U32 },
	84	[NFTA_NAT_REG_ADDR_MIN] = { .type = NLA_U32 },
	85	[NFTA_NAT_REG_ADDR_MAX] = { .type = NLA_U32 },
	86	[NFTA_NAT_REG_PROTO_MIN] = { .type = NLA_U32 },
	87	[NFTA_NAT_REG_PROTO_MAX] = { .type = NLA_U32 },
e42eff8a	88	[NFTA_NAT_FLAGS] = { .type = NLA_U32 },
eb31628e TB	89	};
eb31628e TB	90
75e8d06d PNA	91	static int nft_nat_validate(const struct nft_ctx *ctx,
	92	const struct nft_expr *expr,
	93	const struct nft_data **data)
eb31628e TB	94	{
	95	struct nft_nat *priv = nft_expr_priv(expr);
	96	int err;
	97
7210e4e3 PNA	98	err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
	99	if (err < 0)
	100	return err;
	101
75e8d06d PNA	102	switch (priv->type) {
	103	case NFT_NAT_SNAT:
	104	err = nft_chain_validate_hooks(ctx->chain,
	105	(1 << NF_INET_POST_ROUTING) \|
	106	(1 << NF_INET_LOCAL_IN));
	107	break;
	108	case NFT_NAT_DNAT:
	109	err = nft_chain_validate_hooks(ctx->chain,
	110	(1 << NF_INET_PRE_ROUTING) \|
	111	(1 << NF_INET_LOCAL_OUT));
	112	break;
	113	}
	114
	115	return err;
	116	}
	117
	118	static int nft_nat_init(const struct nft_ctx ctx, const struct nft_expr expr,
	119	const struct nlattr * const tb[])
	120	{
	121	struct nft_nat *priv = nft_expr_priv(expr);
	122	u32 family;
	123	int err;
	124
5c819a39 PNA	125	if (tb[NFTA_NAT_TYPE] == NULL \|\|
	126	(tb[NFTA_NAT_REG_ADDR_MIN] == NULL &&
	127	tb[NFTA_NAT_REG_PROTO_MIN] == NULL))
eb31628e TB	128	return -EINVAL;
	129
	130	switch (ntohl(nla_get_be32(tb[NFTA_NAT_TYPE]))) {
	131	case NFT_NAT_SNAT:
	132	priv->type = NF_NAT_MANIP_SRC;
	133	break;
	134	case NFT_NAT_DNAT:
	135	priv->type = NF_NAT_MANIP_DST;
	136	break;
	137	default:
	138	return -EINVAL;
	139	}
	140
75e8d06d PNA	141	err = nft_nat_validate(ctx, expr, NULL);
	142	if (err < 0)
	143	return err;
	144
eb31628e TB	145	if (tb[NFTA_NAT_FAMILY] == NULL)
	146	return -EINVAL;
	147
a4c2e8be PM	148	family = ntohl(nla_get_be32(tb[NFTA_NAT_FAMILY]));
	149	if (family != AF_INET && family != AF_INET6)
	150	return -EAFNOSUPPORT;
	151	if (family != ctx->afi->family)
	152	return -EOPNOTSUPP;
	153	priv->family = family;
eb31628e TB	154
eb31628e TB	155	if (tb[NFTA_NAT_REG_ADDR_MIN]) {
61cfac6b PNA	156	priv->sreg_addr_min =
	157	ntohl(nla_get_be32(tb[NFTA_NAT_REG_ADDR_MIN]));
	158
eb31628e TB	159	err = nft_validate_input_register(priv->sreg_addr_min);
	160	if (err < 0)
	161	return err;
eb31628e	162
61cfac6b PNA	163	if (tb[NFTA_NAT_REG_ADDR_MAX]) {
	164	priv->sreg_addr_max =
	165	ntohl(nla_get_be32(tb[NFTA_NAT_REG_ADDR_MAX]));
	166
	167	err = nft_validate_input_register(priv->sreg_addr_max);
	168	if (err < 0)
	169	return err;
	170	} else {
	171	priv->sreg_addr_max = priv->sreg_addr_min;
	172	}
	173	}
eb31628e TB	174
eb31628e TB	175	if (tb[NFTA_NAT_REG_PROTO_MIN]) {
61cfac6b PNA	176	priv->sreg_proto_min =
	177	ntohl(nla_get_be32(tb[NFTA_NAT_REG_PROTO_MIN]));
	178
eb31628e TB	179	err = nft_validate_input_register(priv->sreg_proto_min);
	180	if (err < 0)
	181	return err;
eb31628e	182
61cfac6b PNA	183	if (tb[NFTA_NAT_REG_PROTO_MAX]) {
	184	priv->sreg_proto_max =
	185	ntohl(nla_get_be32(tb[NFTA_NAT_REG_PROTO_MAX]));
	186
	187	err = nft_validate_input_register(priv->sreg_proto_max);
	188	if (err < 0)
	189	return err;
	190	} else {
	191	priv->sreg_proto_max = priv->sreg_proto_min;
	192	}
	193	}
eb31628e	194
e42eff8a AB	195	if (tb[NFTA_NAT_FLAGS]) {
	196	priv->flags = ntohl(nla_get_be32(tb[NFTA_NAT_FLAGS]));
	197	if (priv->flags & ~NF_NAT_RANGE_MASK)
	198	return -EINVAL;
	199	}
	200
eb31628e TB	201	return 0;
	202	}
	203
	204	static int nft_nat_dump(struct sk_buff skb, const struct nft_expr expr)
	205	{
	206	const struct nft_nat *priv = nft_expr_priv(expr);
	207
	208	switch (priv->type) {
	209	case NF_NAT_MANIP_SRC:
	210	if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_SNAT)))
	211	goto nla_put_failure;
	212	break;
	213	case NF_NAT_MANIP_DST:
	214	if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_DNAT)))
	215	goto nla_put_failure;
	216	break;
	217	}
	218
	219	if (nla_put_be32(skb, NFTA_NAT_FAMILY, htonl(priv->family)))
	220	goto nla_put_failure;
1e2d56a5 PNA	221
	222	if (priv->sreg_addr_min) {
	223	if (nla_put_be32(skb, NFTA_NAT_REG_ADDR_MIN,
	224	htonl(priv->sreg_addr_min)) \|\|
	225	nla_put_be32(skb, NFTA_NAT_REG_ADDR_MAX,
	226	htonl(priv->sreg_addr_max)))
	227	goto nla_put_failure;
	228	}
	229
91513606 PNA	230	if (priv->sreg_proto_min) {
91513606 PNA	231	if (nla_put_be32(skb, NFTA_NAT_REG_PROTO_MIN,
1e2d56a5 PNA	232	htonl(priv->sreg_proto_min)) \|\|
1e2d56a5 PNA	233	nla_put_be32(skb, NFTA_NAT_REG_PROTO_MAX,
91513606 PNA	234	htonl(priv->sreg_proto_max)))
	235	goto nla_put_failure;
	236	}
e42eff8a AB	237
	238	if (priv->flags != 0) {
	239	if (nla_put_be32(skb, NFTA_NAT_FLAGS, htonl(priv->flags)))
	240	goto nla_put_failure;
	241	}
	242
eb31628e TB	243	return 0;
	244
	245	nla_put_failure:
	246	return -1;
	247	}
	248
	249	static struct nft_expr_type nft_nat_type;
	250	static const struct nft_expr_ops nft_nat_ops = {
	251	.type = &nft_nat_type,
	252	.size = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
	253	.eval = nft_nat_eval,
	254	.init = nft_nat_init,
	255	.dump = nft_nat_dump,
7210e4e3	256	.validate = nft_nat_validate,
eb31628e TB	257	};
	258
	259	static struct nft_expr_type nft_nat_type __read_mostly = {
	260	.name = "nat",
	261	.ops = &nft_nat_ops,
	262	.policy = nft_nat_policy,
	263	.maxattr = NFTA_NAT_MAX,
	264	.owner = THIS_MODULE,
	265	};
	266
	267	static int __init nft_nat_module_init(void)
	268	{
a4c2e8be	269	return nft_register_expr(&nft_nat_type);
eb31628e TB	270	}
	271
	272	static void __exit nft_nat_module_exit(void)
	273	{
	274	nft_unregister_expr(&nft_nat_type);
	275	}
	276
	277	module_init(nft_nat_module_init);
	278	module_exit(nft_nat_module_exit);
	279
	280	MODULE_LICENSE("GPL");
	281	MODULE_AUTHOR("Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>");
	282	MODULE_ALIAS_NFT_EXPR("nat");