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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2012-2016 Pablo Neira Ayuso <[email protected]>
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_core.h>

#define nft_objref_priv(expr)	*((struct nft_object **)nft_expr_priv(expr))

static void nft_objref_eval(const struct nft_expr *expr,
			    struct nft_regs *regs,
			    const struct nft_pktinfo *pkt)
{
	struct nft_object *obj = nft_objref_priv(expr);

	obj->ops->eval(obj, regs, pkt);
}

static int nft_objref_init(const struct nft_ctx *ctx,
			   const struct nft_expr *expr,
			   const struct nlattr * const tb[])
{
	struct nft_object *obj = nft_objref_priv(expr);
	u8 genmask = nft_genmask_next(ctx->net);
	u32 objtype;

	if (!tb[NFTA_OBJREF_IMM_NAME] ||
	    !tb[NFTA_OBJREF_IMM_TYPE])
		return -EINVAL;

	objtype = ntohl(nla_get_be32(tb[NFTA_OBJREF_IMM_TYPE]));
	obj = nft_obj_lookup(ctx->net, ctx->table,
			     tb[NFTA_OBJREF_IMM_NAME], objtype,
			     genmask);
	if (IS_ERR(obj))
		return -ENOENT;

	nft_objref_priv(expr) = obj;
	obj->use++;

	return 0;
}

static int nft_objref_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
	const struct nft_object *obj = nft_objref_priv(expr);

	if (nla_put_string(skb, NFTA_OBJREF_IMM_NAME, obj->key.name) ||
	    nla_put_be32(skb, NFTA_OBJREF_IMM_TYPE,
			 htonl(obj->ops->type->type)))
		goto nla_put_failure;

	return 0;

nla_put_failure:
	return -1;
}

static void nft_objref_deactivate(const struct nft_ctx *ctx,
				  const struct nft_expr *expr,
				  enum nft_trans_phase phase)
{
	struct nft_object *obj = nft_objref_priv(expr);

	if (phase == NFT_TRANS_COMMIT)
		return;

	obj->use--;
}

static void nft_objref_activate(const struct nft_ctx *ctx,
				const struct nft_expr *expr)
{
	struct nft_object *obj = nft_objref_priv(expr);

	obj->use++;
}

static struct nft_expr_type nft_objref_type;
static const struct nft_expr_ops nft_objref_ops = {
	.type		= &nft_objref_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_object *)),
	.eval		= nft_objref_eval,
	.init		= nft_objref_init,
	.activate	= nft_objref_activate,
	.deactivate	= nft_objref_deactivate,
	.dump		= nft_objref_dump,
};

struct nft_objref_map {
	struct nft_set		*set;
	u8			sreg;
	struct nft_set_binding	binding;
};

static void nft_objref_map_eval(const struct nft_expr *expr,
				struct nft_regs *regs,
				const struct nft_pktinfo *pkt)
{
	struct nft_objref_map *priv = nft_expr_priv(expr);
	const struct nft_set *set = priv->set;
	struct net *net = nft_net(pkt);
	const struct nft_set_ext *ext;
	struct nft_object *obj;
	bool found;

	found = nft_set_do_lookup(net, set, &regs->data[priv->sreg], &ext);
	if (!found) {
		ext = nft_set_catchall_lookup(net, set);
		if (!ext) {
			regs->verdict.code = NFT_BREAK;
			return;
		}
	}
	obj = *nft_set_ext_obj(ext);
	obj->ops->eval(obj, regs, pkt);
}

static int nft_objref_map_init(const struct nft_ctx *ctx,
			       const struct nft_expr *expr,
			       const struct nlattr * const tb[])
{
	struct nft_objref_map *priv = nft_expr_priv(expr);
	u8 genmask = nft_genmask_next(ctx->net);
	struct nft_set *set;
	int err;

	set = nft_set_lookup_global(ctx->net, ctx->table,
				    tb[NFTA_OBJREF_SET_NAME],
				    tb[NFTA_OBJREF_SET_ID], genmask);
	if (IS_ERR(set))
		return PTR_ERR(set);

	if (!(set->flags & NFT_SET_OBJECT))
		return -EINVAL;

	err = nft_parse_register_load(tb[NFTA_OBJREF_SET_SREG], &priv->sreg,
				      set->klen);
	if (err < 0)
		return err;

	priv->binding.flags = set->flags & NFT_SET_OBJECT;

	err = nf_tables_bind_set(ctx, set, &priv->binding);
	if (err < 0)
		return err;

	priv->set = set;
	return 0;
}

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

	if (nft_dump_register(skb, NFTA_OBJREF_SET_SREG, priv->sreg) ||
	    nla_put_string(skb, NFTA_OBJREF_SET_NAME, priv->set->name))
		goto nla_put_failure;

	return 0;

nla_put_failure:
	return -1;
}

static void nft_objref_map_deactivate(const struct nft_ctx *ctx,
				      const struct nft_expr *expr,
				      enum nft_trans_phase phase)
{
	struct nft_objref_map *priv = nft_expr_priv(expr);

	nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
}

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

	priv->set->use++;
}

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

	nf_tables_destroy_set(ctx, priv->set);
}

static struct nft_expr_type nft_objref_type;
static const struct nft_expr_ops nft_objref_map_ops = {
	.type		= &nft_objref_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_objref_map)),
	.eval		= nft_objref_map_eval,
	.init		= nft_objref_map_init,
	.activate	= nft_objref_map_activate,
	.deactivate	= nft_objref_map_deactivate,
	.destroy	= nft_objref_map_destroy,
	.dump		= nft_objref_map_dump,
};

static const struct nft_expr_ops *
nft_objref_select_ops(const struct nft_ctx *ctx,
                      const struct nlattr * const tb[])
{
	if (tb[NFTA_OBJREF_SET_SREG] &&
	    (tb[NFTA_OBJREF_SET_NAME] ||
	     tb[NFTA_OBJREF_SET_ID]))
		return &nft_objref_map_ops;
	else if (tb[NFTA_OBJREF_IMM_NAME] &&
		 tb[NFTA_OBJREF_IMM_TYPE])
		return &nft_objref_ops;

	return ERR_PTR(-EOPNOTSUPP);
}

static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = {
	[NFTA_OBJREF_IMM_NAME]	= { .type = NLA_STRING,
				    .len = NFT_OBJ_MAXNAMELEN - 1 },
	[NFTA_OBJREF_IMM_TYPE]	= { .type = NLA_U32 },
	[NFTA_OBJREF_SET_SREG]	= { .type = NLA_U32 },
	[NFTA_OBJREF_SET_NAME]	= { .type = NLA_STRING,
				    .len = NFT_SET_MAXNAMELEN - 1 },
	[NFTA_OBJREF_SET_ID]	= { .type = NLA_U32 },
};

static struct nft_expr_type nft_objref_type __read_mostly = {
	.name		= "objref",
	.select_ops	= nft_objref_select_ops,
	.policy		= nft_objref_policy,
	.maxattr	= NFTA_OBJREF_MAX,
	.owner		= THIS_MODULE,
};

static int __init nft_objref_module_init(void)
{
	return nft_register_expr(&nft_objref_type);
}

static void __exit nft_objref_module_exit(void)
{
	nft_unregister_expr(&nft_objref_type);
}

module_init(nft_objref_module_init);
module_exit(nft_objref_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pablo Neira Ayuso <[email protected]>");
MODULE_ALIAS_NFT_EXPR("objref");
MODULE_DESCRIPTION("nftables stateful object reference module");
Commit	Line	Data
75a6faf6	1	// SPDX-License-Identifier: GPL-2.0-only
c97d22e6 PNA	2	/*
c97d22e6 PNA	3	* Copyright (c) 2012-2016 Pablo Neira Ayuso <[email protected]>
c97d22e6 PNA	4	*/
	5
	6	#include <linux/init.h>
	7	#include <linux/module.h>
	8	#include <linux/skbuff.h>
	9	#include <linux/netlink.h>
	10	#include <linux/netfilter.h>
	11	#include <linux/netfilter/nf_tables.h>
0974cff3	12	#include <net/netfilter/nf_tables_core.h>
c97d22e6 PNA	13
	14	#define nft_objref_priv(expr) ((struct nft_object *)nft_expr_priv(expr))
	15
	16	static void nft_objref_eval(const struct nft_expr *expr,
	17	struct nft_regs *regs,
	18	const struct nft_pktinfo *pkt)
	19	{
	20	struct nft_object *obj = nft_objref_priv(expr);
	21
dfc46034	22	obj->ops->eval(obj, regs, pkt);
c97d22e6 PNA	23	}
	24
	25	static int nft_objref_init(const struct nft_ctx *ctx,
	26	const struct nft_expr *expr,
	27	const struct nlattr * const tb[])
	28	{
	29	struct nft_object *obj = nft_objref_priv(expr);
	30	u8 genmask = nft_genmask_next(ctx->net);
	31	u32 objtype;
	32
	33	if (!tb[NFTA_OBJREF_IMM_NAME] \|\|
	34	!tb[NFTA_OBJREF_IMM_TYPE])
	35	return -EINVAL;
	36
	37	objtype = ntohl(nla_get_be32(tb[NFTA_OBJREF_IMM_TYPE]));
4d44175a FW	38	obj = nft_obj_lookup(ctx->net, ctx->table,
4d44175a FW	39	tb[NFTA_OBJREF_IMM_NAME], objtype,
cac20fcd	40	genmask);
c97d22e6 PNA	41	if (IS_ERR(obj))
	42	return -ENOENT;
	43
	44	nft_objref_priv(expr) = obj;
	45	obj->use++;
	46
	47	return 0;
	48	}
	49
	50	static int nft_objref_dump(struct sk_buff skb, const struct nft_expr expr)
	51	{
	52	const struct nft_object *obj = nft_objref_priv(expr);
	53
d152159b	54	if (nla_put_string(skb, NFTA_OBJREF_IMM_NAME, obj->key.name) \|\|
dfc46034 PBG	55	nla_put_be32(skb, NFTA_OBJREF_IMM_TYPE,
dfc46034 PBG	56	htonl(obj->ops->type->type)))
c97d22e6 PNA	57	goto nla_put_failure;
	58
	59	return 0;
	60
	61	nla_put_failure:
	62	return -1;
	63	}
	64
8ffcd32f PNA	65	static void nft_objref_deactivate(const struct nft_ctx *ctx,
	66	const struct nft_expr *expr,
	67	enum nft_trans_phase phase)
c97d22e6 PNA	68	{
	69	struct nft_object *obj = nft_objref_priv(expr);
	70
8ffcd32f PNA	71	if (phase == NFT_TRANS_COMMIT)
	72	return;
	73
c97d22e6 PNA	74	obj->use--;
	75	}
	76
8ffcd32f PNA	77	static void nft_objref_activate(const struct nft_ctx *ctx,
	78	const struct nft_expr *expr)
	79	{
	80	struct nft_object *obj = nft_objref_priv(expr);
	81
	82	obj->use++;
	83	}
	84
c97d22e6 PNA	85	static struct nft_expr_type nft_objref_type;
	86	static const struct nft_expr_ops nft_objref_ops = {
	87	.type = &nft_objref_type,
	88	.size = NFT_EXPR_SIZE(sizeof(struct nft_object *)),
	89	.eval = nft_objref_eval,
	90	.init = nft_objref_init,
8ffcd32f PNA	91	.activate = nft_objref_activate,
8ffcd32f PNA	92	.deactivate = nft_objref_deactivate,
c97d22e6 PNA	93	.dump = nft_objref_dump,
	94	};
	95
63aea290 PNA	96	struct nft_objref_map {
63aea290 PNA	97	struct nft_set *set;
4f16d25c	98	u8 sreg;
63aea290 PNA	99	struct nft_set_binding binding;
	100	};
	101
	102	static void nft_objref_map_eval(const struct nft_expr *expr,
	103	struct nft_regs *regs,
	104	const struct nft_pktinfo *pkt)
	105	{
	106	struct nft_objref_map *priv = nft_expr_priv(expr);
	107	const struct nft_set *set = priv->set;
aaa31047	108	struct net *net = nft_net(pkt);
63aea290 PNA	109	const struct nft_set_ext *ext;
	110	struct nft_object *obj;
	111	bool found;
	112
0974cff3	113	found = nft_set_do_lookup(net, set, &regs->data[priv->sreg], &ext);
63aea290	114	if (!found) {
aaa31047 PNA	115	ext = nft_set_catchall_lookup(net, set);
	116	if (!ext) {
	117	regs->verdict.code = NFT_BREAK;
	118	return;
	119	}
63aea290 PNA	120	}
63aea290 PNA	121	obj = *nft_set_ext_obj(ext);
dfc46034	122	obj->ops->eval(obj, regs, pkt);
63aea290 PNA	123	}
	124
	125	static int nft_objref_map_init(const struct nft_ctx *ctx,
	126	const struct nft_expr *expr,
	127	const struct nlattr * const tb[])
	128	{
	129	struct nft_objref_map *priv = nft_expr_priv(expr);
	130	u8 genmask = nft_genmask_next(ctx->net);
	131	struct nft_set *set;
	132	int err;
	133
10659cba PNA	134	set = nft_set_lookup_global(ctx->net, ctx->table,
	135	tb[NFTA_OBJREF_SET_NAME],
	136	tb[NFTA_OBJREF_SET_ID], genmask);
c7a72e3f PNA	137	if (IS_ERR(set))
c7a72e3f PNA	138	return PTR_ERR(set);
63aea290 PNA	139
	140	if (!(set->flags & NFT_SET_OBJECT))
	141	return -EINVAL;
	142
4f16d25c PNA	143	err = nft_parse_register_load(tb[NFTA_OBJREF_SET_SREG], &priv->sreg,
4f16d25c PNA	144	set->klen);
63aea290 PNA	145	if (err < 0)
	146	return err;
	147
	148	priv->binding.flags = set->flags & NFT_SET_OBJECT;
	149
	150	err = nf_tables_bind_set(ctx, set, &priv->binding);
	151	if (err < 0)
	152	return err;
	153
	154	priv->set = set;
	155	return 0;
	156	}
	157
	158	static int nft_objref_map_dump(struct sk_buff skb, const struct nft_expr expr)
	159	{
	160	const struct nft_objref_map *priv = nft_expr_priv(expr);
	161
	162	if (nft_dump_register(skb, NFTA_OBJREF_SET_SREG, priv->sreg) \|\|
	163	nla_put_string(skb, NFTA_OBJREF_SET_NAME, priv->set->name))
	164	goto nla_put_failure;
	165
	166	return 0;
	167
	168	nla_put_failure:
	169	return -1;
	170	}
	171
cd5125d8	172	static void nft_objref_map_deactivate(const struct nft_ctx *ctx,
f6ac8585 PNA	173	const struct nft_expr *expr,
f6ac8585 PNA	174	enum nft_trans_phase phase)
cd5125d8 FW	175	{
	176	struct nft_objref_map *priv = nft_expr_priv(expr);
	177
273fe3f1 PNA	178	nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
	179	}
	180
	181	static void nft_objref_map_activate(const struct nft_ctx *ctx,
	182	const struct nft_expr *expr)
	183	{
	184	struct nft_objref_map *priv = nft_expr_priv(expr);
f6ac8585	185
273fe3f1	186	priv->set->use++;
cd5125d8 FW	187	}
cd5125d8 FW	188
63aea290 PNA	189	static void nft_objref_map_destroy(const struct nft_ctx *ctx,
	190	const struct nft_expr *expr)
	191	{
	192	struct nft_objref_map *priv = nft_expr_priv(expr);
	193
cd5125d8	194	nf_tables_destroy_set(ctx, priv->set);
63aea290 PNA	195	}
	196
	197	static struct nft_expr_type nft_objref_type;
	198	static const struct nft_expr_ops nft_objref_map_ops = {
	199	.type = &nft_objref_type,
	200	.size = NFT_EXPR_SIZE(sizeof(struct nft_objref_map)),
	201	.eval = nft_objref_map_eval,
	202	.init = nft_objref_map_init,
273fe3f1	203	.activate = nft_objref_map_activate,
cd5125d8	204	.deactivate = nft_objref_map_deactivate,
63aea290 PNA	205	.destroy = nft_objref_map_destroy,
	206	.dump = nft_objref_map_dump,
	207	};
	208
	209	static const struct nft_expr_ops *
	210	nft_objref_select_ops(const struct nft_ctx *ctx,
	211	const struct nlattr * const tb[])
	212	{
	213	if (tb[NFTA_OBJREF_SET_SREG] &&
	214	(tb[NFTA_OBJREF_SET_NAME] \|\|
	215	tb[NFTA_OBJREF_SET_ID]))
	216	return &nft_objref_map_ops;
	217	else if (tb[NFTA_OBJREF_IMM_NAME] &&
	218	tb[NFTA_OBJREF_IMM_TYPE])
	219	return &nft_objref_ops;
	220
	221	return ERR_PTR(-EOPNOTSUPP);
	222	}
	223
c97d22e6	224	static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = {
b2fbd044 LZ	225	[NFTA_OBJREF_IMM_NAME] = { .type = NLA_STRING,
b2fbd044 LZ	226	.len = NFT_OBJ_MAXNAMELEN - 1 },
c97d22e6	227	[NFTA_OBJREF_IMM_TYPE] = { .type = NLA_U32 },
63aea290	228	[NFTA_OBJREF_SET_SREG] = { .type = NLA_U32 },
b2fbd044 LZ	229	[NFTA_OBJREF_SET_NAME] = { .type = NLA_STRING,
b2fbd044 LZ	230	.len = NFT_SET_MAXNAMELEN - 1 },
63aea290	231	[NFTA_OBJREF_SET_ID] = { .type = NLA_U32 },
c97d22e6 PNA	232	};
	233
	234	static struct nft_expr_type nft_objref_type __read_mostly = {
	235	.name = "objref",
63aea290	236	.select_ops = nft_objref_select_ops,
c97d22e6 PNA	237	.policy = nft_objref_policy,
	238	.maxattr = NFTA_OBJREF_MAX,
	239	.owner = THIS_MODULE,
	240	};
	241
	242	static int __init nft_objref_module_init(void)
	243	{
	244	return nft_register_expr(&nft_objref_type);
	245	}
	246
	247	static void __exit nft_objref_module_exit(void)
	248	{
	249	nft_unregister_expr(&nft_objref_type);
	250	}
	251
	252	module_init(nft_objref_module_init);
	253	module_exit(nft_objref_module_exit);
	254
	255	MODULE_LICENSE("GPL");
	256	MODULE_AUTHOR("Pablo Neira Ayuso <[email protected]>");
	257	MODULE_ALIAS_NFT_EXPR("objref");
4cacc395	258	MODULE_DESCRIPTION("nftables stateful object reference module");