[linux.git] / net / netfilter / nft_nat.c

/*
 * Copyright (c) 2008-2009 Patrick McHardy <[email protected]>
 * Copyright (c) 2012 Pablo Neira Ayuso <[email protected]>
 * 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_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_range range;

	memset(&range, 0, sizeof(range));
	if (priv->sreg_addr_min) {
		if (priv->family == 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];

		} else {
			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));
		}
		range.flags |= NF_NAT_RANGE_MAP_IPS;
	}

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

	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 -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 != ctx->afi->family)
		return -EOPNOTSUPP;

	switch (family) {
	case NFPROTO_IPV4:
		alen = FIELD_SIZEOF(struct nf_nat_range, min_addr.ip);
		break;
	case NFPROTO_IPV6:
		alen = FIELD_SIZEOF(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;
		}
	}

	plen = FIELD_SIZEOF(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;
		}
	}

	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 (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 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 <[email protected]>");
MODULE_ALIAS_NFT_EXPR("nat");
Commit	Line	Data
eb31628e TB	1	/*
	2	* Copyright (c) 2008-2009 Patrick McHardy <[email protected]>
	3	* Copyright (c) 2012 Pablo Neira Ayuso <[email protected]>
	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,
a55e22e9	40	struct nft_regs *regs,
eb31628e TB	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	51	range.min_addr.ip = (__force __be32)
49499c3e	52	regs->data[priv->sreg_addr_min];
98c37b6b	53	range.max_addr.ip = (__force __be32)
49499c3e	54	regs->data[priv->sreg_addr_max];
eb31628e TB	55
	56	} else {
	57	memcpy(range.min_addr.ip6,
49499c3e PM	58	&regs->data[priv->sreg_addr_min],
49499c3e PM	59	sizeof(range.min_addr.ip6));
eb31628e	60	memcpy(range.max_addr.ip6,
49499c3e PM	61	&regs->data[priv->sreg_addr_max],
49499c3e PM	62	sizeof(range.max_addr.ip6));
eb31628e TB	63	}
	64	range.flags \|= NF_NAT_RANGE_MAP_IPS;
	65	}
	66
	67	if (priv->sreg_proto_min) {
7b5bca46	68	range.min_proto.all =
49499c3e	69	(__be16 )&regs->data[priv->sreg_proto_min];
7b5bca46	70	range.max_proto.all =
49499c3e	71	(__be16 )&regs->data[priv->sreg_proto_max];
eb31628e TB	72	range.flags \|= NF_NAT_RANGE_PROTO_SPECIFIED;
	73	}
	74
e42eff8a AB	75	range.flags \|= priv->flags;
e42eff8a AB	76
a55e22e9	77	regs->verdict.code = nf_nat_setup_info(ct, &range, priv->type);
eb31628e TB	78	}
	79
	80	static const struct nla_policy nft_nat_policy[NFTA_NAT_MAX + 1] = {
	81	[NFTA_NAT_TYPE] = { .type = NLA_U32 },
	82	[NFTA_NAT_FAMILY] = { .type = NLA_U32 },
	83	[NFTA_NAT_REG_ADDR_MIN] = { .type = NLA_U32 },
	84	[NFTA_NAT_REG_ADDR_MAX] = { .type = NLA_U32 },
	85	[NFTA_NAT_REG_PROTO_MIN] = { .type = NLA_U32 },
	86	[NFTA_NAT_REG_PROTO_MAX] = { .type = NLA_U32 },
e42eff8a	87	[NFTA_NAT_FLAGS] = { .type = NLA_U32 },
eb31628e TB	88	};
eb31628e TB	89
75e8d06d PNA	90	static int nft_nat_validate(const struct nft_ctx *ctx,
	91	const struct nft_expr *expr,
	92	const struct nft_data **data)
eb31628e TB	93	{
	94	struct nft_nat *priv = nft_expr_priv(expr);
	95	int err;
	96
7210e4e3 PNA	97	err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
	98	if (err < 0)
	99	return err;
	100
75e8d06d PNA	101	switch (priv->type) {
	102	case NFT_NAT_SNAT:
	103	err = nft_chain_validate_hooks(ctx->chain,
	104	(1 << NF_INET_POST_ROUTING) \|
	105	(1 << NF_INET_LOCAL_IN));
	106	break;
	107	case NFT_NAT_DNAT:
	108	err = nft_chain_validate_hooks(ctx->chain,
	109	(1 << NF_INET_PRE_ROUTING) \|
	110	(1 << NF_INET_LOCAL_OUT));
	111	break;
	112	}
	113
	114	return err;
	115	}
	116
	117	static int nft_nat_init(const struct nft_ctx ctx, const struct nft_expr expr,
	118	const struct nlattr * const tb[])
	119	{
	120	struct nft_nat *priv = nft_expr_priv(expr);
d07db988	121	unsigned int alen, plen;
75e8d06d PNA	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	148	family = ntohl(nla_get_be32(tb[NFTA_NAT_FAMILY]));
a4c2e8be PM	149	if (family != ctx->afi->family)
a4c2e8be PM	150	return -EOPNOTSUPP;
d07db988 PM	151
	152	switch (family) {
	153	case NFPROTO_IPV4:
	154	alen = FIELD_SIZEOF(struct nf_nat_range, min_addr.ip);
	155	break;
	156	case NFPROTO_IPV6:
	157	alen = FIELD_SIZEOF(struct nf_nat_range, min_addr.ip6);
	158	break;
	159	default:
	160	return -EAFNOSUPPORT;
	161	}
a4c2e8be	162	priv->family = family;
eb31628e TB	163
eb31628e TB	164	if (tb[NFTA_NAT_REG_ADDR_MIN]) {
61cfac6b	165	priv->sreg_addr_min =
b1c96ed3	166	nft_parse_register(tb[NFTA_NAT_REG_ADDR_MIN]);
d07db988	167	err = nft_validate_register_load(priv->sreg_addr_min, alen);
eb31628e TB	168	if (err < 0)
eb31628e TB	169	return err;
eb31628e	170
61cfac6b PNA	171	if (tb[NFTA_NAT_REG_ADDR_MAX]) {
61cfac6b PNA	172	priv->sreg_addr_max =
b1c96ed3	173	nft_parse_register(tb[NFTA_NAT_REG_ADDR_MAX]);
61cfac6b	174
d07db988 PM	175	err = nft_validate_register_load(priv->sreg_addr_max,
d07db988 PM	176	alen);
61cfac6b PNA	177	if (err < 0)
	178	return err;
	179	} else {
	180	priv->sreg_addr_max = priv->sreg_addr_min;
	181	}
	182	}
eb31628e	183
d07db988	184	plen = FIELD_SIZEOF(struct nf_nat_range, min_addr.all);
eb31628e	185	if (tb[NFTA_NAT_REG_PROTO_MIN]) {
61cfac6b	186	priv->sreg_proto_min =
b1c96ed3	187	nft_parse_register(tb[NFTA_NAT_REG_PROTO_MIN]);
61cfac6b	188
d07db988	189	err = nft_validate_register_load(priv->sreg_proto_min, plen);
eb31628e TB	190	if (err < 0)
eb31628e TB	191	return err;
eb31628e	192
61cfac6b PNA	193	if (tb[NFTA_NAT_REG_PROTO_MAX]) {
61cfac6b PNA	194	priv->sreg_proto_max =
b1c96ed3	195	nft_parse_register(tb[NFTA_NAT_REG_PROTO_MAX]);
61cfac6b	196
d07db988 PM	197	err = nft_validate_register_load(priv->sreg_proto_max,
d07db988 PM	198	plen);
61cfac6b PNA	199	if (err < 0)
	200	return err;
	201	} else {
	202	priv->sreg_proto_max = priv->sreg_proto_min;
	203	}
	204	}
eb31628e	205
e42eff8a AB	206	if (tb[NFTA_NAT_FLAGS]) {
	207	priv->flags = ntohl(nla_get_be32(tb[NFTA_NAT_FLAGS]));
	208	if (priv->flags & ~NF_NAT_RANGE_MASK)
	209	return -EINVAL;
	210	}
	211
eb31628e TB	212	return 0;
	213	}
	214
	215	static int nft_nat_dump(struct sk_buff skb, const struct nft_expr expr)
	216	{
	217	const struct nft_nat *priv = nft_expr_priv(expr);
	218
	219	switch (priv->type) {
	220	case NF_NAT_MANIP_SRC:
	221	if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_SNAT)))
	222	goto nla_put_failure;
	223	break;
	224	case NF_NAT_MANIP_DST:
	225	if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_DNAT)))
	226	goto nla_put_failure;
	227	break;
	228	}
	229
	230	if (nla_put_be32(skb, NFTA_NAT_FAMILY, htonl(priv->family)))
	231	goto nla_put_failure;
1e2d56a5 PNA	232
1e2d56a5 PNA	233	if (priv->sreg_addr_min) {
b1c96ed3 PM	234	if (nft_dump_register(skb, NFTA_NAT_REG_ADDR_MIN,
	235	priv->sreg_addr_min) \|\|
	236	nft_dump_register(skb, NFTA_NAT_REG_ADDR_MAX,
	237	priv->sreg_addr_max))
1e2d56a5 PNA	238	goto nla_put_failure;
	239	}
	240
91513606	241	if (priv->sreg_proto_min) {
b1c96ed3 PM	242	if (nft_dump_register(skb, NFTA_NAT_REG_PROTO_MIN,
	243	priv->sreg_proto_min) \|\|
	244	nft_dump_register(skb, NFTA_NAT_REG_PROTO_MAX,
	245	priv->sreg_proto_max))
91513606 PNA	246	goto nla_put_failure;
91513606 PNA	247	}
e42eff8a AB	248
	249	if (priv->flags != 0) {
	250	if (nla_put_be32(skb, NFTA_NAT_FLAGS, htonl(priv->flags)))
	251	goto nla_put_failure;
	252	}
	253
eb31628e TB	254	return 0;
	255
	256	nla_put_failure:
	257	return -1;
	258	}
	259
	260	static struct nft_expr_type nft_nat_type;
	261	static const struct nft_expr_ops nft_nat_ops = {
	262	.type = &nft_nat_type,
	263	.size = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
	264	.eval = nft_nat_eval,
	265	.init = nft_nat_init,
	266	.dump = nft_nat_dump,
7210e4e3	267	.validate = nft_nat_validate,
eb31628e TB	268	};
	269
	270	static struct nft_expr_type nft_nat_type __read_mostly = {
	271	.name = "nat",
	272	.ops = &nft_nat_ops,
	273	.policy = nft_nat_policy,
	274	.maxattr = NFTA_NAT_MAX,
	275	.owner = THIS_MODULE,
	276	};
	277
	278	static int __init nft_nat_module_init(void)
	279	{
a4c2e8be	280	return nft_register_expr(&nft_nat_type);
eb31628e TB	281	}
	282
	283	static void __exit nft_nat_module_exit(void)
	284	{
	285	nft_unregister_expr(&nft_nat_type);
	286	}
	287
	288	module_init(nft_nat_module_init);
	289	module_exit(nft_nat_module_exit);
	290
	291	MODULE_LICENSE("GPL");
	292	MODULE_AUTHOR("Tomasz Bursztyka <[email protected]>");
	293	MODULE_ALIAS_NFT_EXPR("nat");