[mirror_ubuntu-bionic-kernel.git] / net / netfilter / nft_dynset.c

/*
 * Copyright (c) 2015 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.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.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_tables_core.h>

struct nft_dynset {
	struct nft_set			*set;
	struct nft_set_ext_tmpl		tmpl;
	enum nft_dynset_ops		op:8;
	enum nft_registers		sreg_key:8;
	enum nft_registers		sreg_data:8;
	bool				invert;
	u64				timeout;
	struct nft_expr			*expr;
	struct nft_set_binding		binding;
};

static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr,
			    struct nft_regs *regs)
{
	const struct nft_dynset *priv = nft_expr_priv(expr);
	struct nft_set_ext *ext;
	u64 timeout;
	void *elem;

	if (set->size && !atomic_add_unless(&set->nelems, 1, set->size))
		return NULL;

	timeout = priv->timeout ? : set->timeout;
	elem = nft_set_elem_init(set, &priv->tmpl,
				 &regs->data[priv->sreg_key],
				 &regs->data[priv->sreg_data],
				 timeout, GFP_ATOMIC);
	if (elem == NULL)
		goto err1;

	ext = nft_set_elem_ext(set, elem);
	if (priv->expr != NULL &&
	    nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0)
		goto err2;

	return elem;

err2:
	nft_set_elem_destroy(set, elem, false);
err1:
	if (set->size)
		atomic_dec(&set->nelems);
	return NULL;
}

static void nft_dynset_eval(const struct nft_expr *expr,
			    struct nft_regs *regs,
			    const struct nft_pktinfo *pkt)
{
	const struct nft_dynset *priv = nft_expr_priv(expr);
	struct nft_set *set = priv->set;
	const struct nft_set_ext *ext;
	const struct nft_expr *sexpr;
	u64 timeout;

	if (set->ops->update(set, &regs->data[priv->sreg_key], nft_dynset_new,
			     expr, regs, &ext)) {
		sexpr = NULL;
		if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR))
			sexpr = nft_set_ext_expr(ext);

		if (priv->op == NFT_DYNSET_OP_UPDATE &&
		    nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
			timeout = priv->timeout ? : set->timeout;
			*nft_set_ext_expiration(ext) = jiffies + timeout;
		}

		if (sexpr != NULL)
			sexpr->ops->eval(sexpr, regs, pkt);

		if (priv->invert)
			regs->verdict.code = NFT_BREAK;
		return;
	}

	if (!priv->invert)
		regs->verdict.code = NFT_BREAK;
}

static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
	[NFTA_DYNSET_SET_NAME]	= { .type = NLA_STRING,
				    .len = NFT_SET_MAXNAMELEN - 1 },
	[NFTA_DYNSET_SET_ID]	= { .type = NLA_U32 },
	[NFTA_DYNSET_OP]	= { .type = NLA_U32 },
	[NFTA_DYNSET_SREG_KEY]	= { .type = NLA_U32 },
	[NFTA_DYNSET_SREG_DATA]	= { .type = NLA_U32 },
	[NFTA_DYNSET_TIMEOUT]	= { .type = NLA_U64 },
	[NFTA_DYNSET_EXPR]	= { .type = NLA_NESTED },
	[NFTA_DYNSET_FLAGS]	= { .type = NLA_U32 },
};

static int nft_dynset_init(const struct nft_ctx *ctx,
			   const struct nft_expr *expr,
			   const struct nlattr * const tb[])
{
	struct nft_dynset *priv = nft_expr_priv(expr);
	u8 genmask = nft_genmask_next(ctx->net);
	struct nft_set *set;
	u64 timeout;
	int err;

	if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
	    tb[NFTA_DYNSET_OP] == NULL ||
	    tb[NFTA_DYNSET_SREG_KEY] == NULL)
		return -EINVAL;

	if (tb[NFTA_DYNSET_FLAGS]) {
		u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));

		if (flags & ~NFT_DYNSET_F_INV)
			return -EINVAL;
		if (flags & NFT_DYNSET_F_INV)
			priv->invert = true;
	}

	set = nft_set_lookup(ctx->net, ctx->table, tb[NFTA_DYNSET_SET_NAME],
			     tb[NFTA_DYNSET_SET_ID], genmask);
	if (IS_ERR(set))
		return PTR_ERR(set);

	if (set->ops->update == NULL)
		return -EOPNOTSUPP;

	if (set->flags & NFT_SET_CONSTANT)
		return -EBUSY;

	priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
	switch (priv->op) {
	case NFT_DYNSET_OP_ADD:
		break;
	case NFT_DYNSET_OP_UPDATE:
		if (!(set->flags & NFT_SET_TIMEOUT))
			return -EOPNOTSUPP;
		break;
	default:
		return -EOPNOTSUPP;
	}

	timeout = 0;
	if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
		if (!(set->flags & NFT_SET_TIMEOUT))
			return -EINVAL;
		timeout = msecs_to_jiffies(be64_to_cpu(nla_get_be64(
						tb[NFTA_DYNSET_TIMEOUT])));
	}

	priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]);
	err = nft_validate_register_load(priv->sreg_key, set->klen);;
	if (err < 0)
		return err;

	if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
		if (!(set->flags & NFT_SET_MAP))
			return -EINVAL;
		if (set->dtype == NFT_DATA_VERDICT)
			return -EOPNOTSUPP;

		priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]);
		err = nft_validate_register_load(priv->sreg_data, set->dlen);
		if (err < 0)
			return err;
	} else if (set->flags & NFT_SET_MAP)
		return -EINVAL;

	if (tb[NFTA_DYNSET_EXPR] != NULL) {
		if (!(set->flags & NFT_SET_EVAL))
			return -EINVAL;
		if (!(set->flags & NFT_SET_ANONYMOUS))
			return -EOPNOTSUPP;

		priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]);
		if (IS_ERR(priv->expr))
			return PTR_ERR(priv->expr);

		err = -EOPNOTSUPP;
		if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL))
			goto err1;
	} else if (set->flags & NFT_SET_EVAL)
		return -EINVAL;

	nft_set_ext_prepare(&priv->tmpl);
	nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
	if (set->flags & NFT_SET_MAP)
		nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
	if (priv->expr != NULL)
		nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
				       priv->expr->ops->size);
	if (set->flags & NFT_SET_TIMEOUT) {
		if (timeout || set->timeout)
			nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
	}

	priv->timeout = timeout;

	err = nf_tables_bind_set(ctx, set, &priv->binding);
	if (err < 0)
		goto err1;

	priv->set = set;
	return 0;

err1:
	if (priv->expr != NULL)
		nft_expr_destroy(ctx, priv->expr);
	return err;
}

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

	nf_tables_unbind_set(ctx, priv->set, &priv->binding);
	if (priv->expr != NULL)
		nft_expr_destroy(ctx, priv->expr);
}

static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
	const struct nft_dynset *priv = nft_expr_priv(expr);
	u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;

	if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
		goto nla_put_failure;
	if (priv->set->flags & NFT_SET_MAP &&
	    nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
		goto nla_put_failure;
	if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
		goto nla_put_failure;
	if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
		goto nla_put_failure;
	if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
			 cpu_to_be64(jiffies_to_msecs(priv->timeout)),
			 NFTA_DYNSET_PAD))
		goto nla_put_failure;
	if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
		goto nla_put_failure;
	if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -1;
}

static const struct nft_expr_ops nft_dynset_ops = {
	.type		= &nft_dynset_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
	.eval		= nft_dynset_eval,
	.init		= nft_dynset_init,
	.destroy	= nft_dynset_destroy,
	.dump		= nft_dynset_dump,
};

struct nft_expr_type nft_dynset_type __read_mostly = {
	.name		= "dynset",
	.ops		= &nft_dynset_ops,
	.policy		= nft_dynset_policy,
	.maxattr	= NFTA_DYNSET_MAX,
	.owner		= THIS_MODULE,
};
Commit	Line	Data
22fe54d5 PM	1	/*
	2	* Copyright (c) 2015 Patrick McHardy <kaber@trash.net>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*
	8	*/
	9
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/init.h>
	13	#include <linux/netlink.h>
	14	#include <linux/netfilter.h>
	15	#include <linux/netfilter/nf_tables.h>
	16	#include <net/netfilter/nf_tables.h>
	17	#include <net/netfilter/nf_tables_core.h>
	18
	19	struct nft_dynset {
	20	struct nft_set *set;
	21	struct nft_set_ext_tmpl tmpl;
	22	enum nft_dynset_ops op:8;
	23	enum nft_registers sreg_key:8;
	24	enum nft_registers sreg_data:8;
dbd2be06	25	bool invert;
22fe54d5	26	u64 timeout;
3e135cd4	27	struct nft_expr *expr;
22fe54d5 PM	28	struct nft_set_binding binding;
	29	};
	30
	31	static void nft_dynset_new(struct nft_set set, const struct nft_expr *expr,
a55e22e9	32	struct nft_regs *regs)
22fe54d5 PM	33	{
22fe54d5 PM	34	const struct nft_dynset *priv = nft_expr_priv(expr);
3e135cd4	35	struct nft_set_ext *ext;
22fe54d5 PM	36	u64 timeout;
	37	void *elem;
	38
	39	if (set->size && !atomic_add_unless(&set->nelems, 1, set->size))
	40	return NULL;
	41
	42	timeout = priv->timeout ? : set->timeout;
	43	elem = nft_set_elem_init(set, &priv->tmpl,
a55e22e9 PM	44	&regs->data[priv->sreg_key],
a55e22e9 PM	45	&regs->data[priv->sreg_data],
22fe54d5	46	timeout, GFP_ATOMIC);
61f9e292 LZ	47	if (elem == NULL)
61f9e292 LZ	48	goto err1;
3e135cd4 PM	49
3e135cd4 PM	50	ext = nft_set_elem_ext(set, elem);
086f3321 PNA	51	if (priv->expr != NULL &&
086f3321 PNA	52	nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0)
61f9e292	53	goto err2;
3e135cd4	54
22fe54d5	55	return elem;
61f9e292 LZ	56
	57	err2:
	58	nft_set_elem_destroy(set, elem, false);
	59	err1:
	60	if (set->size)
	61	atomic_dec(&set->nelems);
	62	return NULL;
22fe54d5 PM	63	}
	64
	65	static void nft_dynset_eval(const struct nft_expr *expr,
a55e22e9	66	struct nft_regs *regs,
22fe54d5 PM	67	const struct nft_pktinfo *pkt)
	68	{
	69	const struct nft_dynset *priv = nft_expr_priv(expr);
	70	struct nft_set *set = priv->set;
	71	const struct nft_set_ext *ext;
3e135cd4	72	const struct nft_expr *sexpr;
22fe54d5 PM	73	u64 timeout;
22fe54d5 PM	74
a55e22e9 PM	75	if (set->ops->update(set, &regs->data[priv->sreg_key], nft_dynset_new,
a55e22e9 PM	76	expr, regs, &ext)) {
3e135cd4 PM	77	sexpr = NULL;
	78	if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR))
	79	sexpr = nft_set_ext_expr(ext);
	80
22fe54d5 PM	81	if (priv->op == NFT_DYNSET_OP_UPDATE &&
	82	nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
	83	timeout = priv->timeout ? : set->timeout;
	84	*nft_set_ext_expiration(ext) = jiffies + timeout;
277a2928	85	}
22fe54d5	86
3e135cd4 PM	87	if (sexpr != NULL)
3e135cd4 PM	88	sexpr->ops->eval(sexpr, regs, pkt);
dbd2be06 PNA	89
	90	if (priv->invert)
	91	regs->verdict.code = NFT_BREAK;
3e135cd4 PM	92	return;
3e135cd4 PM	93	}
277a2928	94
dbd2be06 PNA	95	if (!priv->invert)
dbd2be06 PNA	96	regs->verdict.code = NFT_BREAK;
22fe54d5 PM	97	}
	98
	99	static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
b2fbd044 LZ	100	[NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING,
b2fbd044 LZ	101	.len = NFT_SET_MAXNAMELEN - 1 },
22fe54d5 PM	102	[NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
	103	[NFTA_DYNSET_OP] = { .type = NLA_U32 },
	104	[NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
	105	[NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
	106	[NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
3e135cd4	107	[NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
dbd2be06	108	[NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
22fe54d5 PM	109	};
	110
	111	static int nft_dynset_init(const struct nft_ctx *ctx,
	112	const struct nft_expr *expr,
	113	const struct nlattr * const tb[])
	114	{
	115	struct nft_dynset *priv = nft_expr_priv(expr);
37a9cc52	116	u8 genmask = nft_genmask_next(ctx->net);
22fe54d5 PM	117	struct nft_set *set;
	118	u64 timeout;
	119	int err;
	120
	121	if (tb[NFTA_DYNSET_SET_NAME] == NULL \|\|
	122	tb[NFTA_DYNSET_OP] == NULL \|\|
	123	tb[NFTA_DYNSET_SREG_KEY] == NULL)
	124	return -EINVAL;
	125
dbd2be06 PNA	126	if (tb[NFTA_DYNSET_FLAGS]) {
	127	u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
	128
	129	if (flags & ~NFT_DYNSET_F_INV)
	130	return -EINVAL;
	131	if (flags & NFT_DYNSET_F_INV)
	132	priv->invert = true;
	133	}
	134
c7a72e3f PNA	135	set = nft_set_lookup(ctx->net, ctx->table, tb[NFTA_DYNSET_SET_NAME],
	136	tb[NFTA_DYNSET_SET_ID], genmask);
	137	if (IS_ERR(set))
	138	return PTR_ERR(set);
22fe54d5	139
bb6a6e8e LZ	140	if (set->ops->update == NULL)
	141	return -EOPNOTSUPP;
	142
22fe54d5 PM	143	if (set->flags & NFT_SET_CONSTANT)
	144	return -EBUSY;
	145
	146	priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
	147	switch (priv->op) {
	148	case NFT_DYNSET_OP_ADD:
	149	break;
	150	case NFT_DYNSET_OP_UPDATE:
	151	if (!(set->flags & NFT_SET_TIMEOUT))
	152	return -EOPNOTSUPP;
	153	break;
	154	default:
	155	return -EOPNOTSUPP;
	156	}
	157
	158	timeout = 0;
	159	if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
	160	if (!(set->flags & NFT_SET_TIMEOUT))
	161	return -EINVAL;
a8b1e36d AP	162	timeout = msecs_to_jiffies(be64_to_cpu(nla_get_be64(
a8b1e36d AP	163	tb[NFTA_DYNSET_TIMEOUT])));
22fe54d5 PM	164	}
22fe54d5 PM	165
b1c96ed3	166	priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]);
d07db988	167	err = nft_validate_register_load(priv->sreg_key, set->klen);;
22fe54d5 PM	168	if (err < 0)
	169	return err;
	170
	171	if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
	172	if (!(set->flags & NFT_SET_MAP))
	173	return -EINVAL;
	174	if (set->dtype == NFT_DATA_VERDICT)
	175	return -EOPNOTSUPP;
	176
b1c96ed3	177	priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]);
d07db988	178	err = nft_validate_register_load(priv->sreg_data, set->dlen);
22fe54d5 PM	179	if (err < 0)
	180	return err;
	181	} else if (set->flags & NFT_SET_MAP)
	182	return -EINVAL;
	183
3e135cd4 PM	184	if (tb[NFTA_DYNSET_EXPR] != NULL) {
	185	if (!(set->flags & NFT_SET_EVAL))
	186	return -EINVAL;
	187	if (!(set->flags & NFT_SET_ANONYMOUS))
	188	return -EOPNOTSUPP;
	189
	190	priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]);
	191	if (IS_ERR(priv->expr))
	192	return PTR_ERR(priv->expr);
	193
	194	err = -EOPNOTSUPP;
	195	if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL))
	196	goto err1;
	197	} else if (set->flags & NFT_SET_EVAL)
	198	return -EINVAL;
	199
22fe54d5 PM	200	nft_set_ext_prepare(&priv->tmpl);
	201	nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
	202	if (set->flags & NFT_SET_MAP)
	203	nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
3e135cd4 PM	204	if (priv->expr != NULL)
	205	nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
	206	priv->expr->ops->size);
22fe54d5 PM	207	if (set->flags & NFT_SET_TIMEOUT) {
	208	if (timeout \|\| set->timeout)
	209	nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
	210	}
	211
	212	priv->timeout = timeout;
	213
	214	err = nf_tables_bind_set(ctx, set, &priv->binding);
	215	if (err < 0)
3e135cd4	216	goto err1;
22fe54d5 PM	217
	218	priv->set = set;
	219	return 0;
3e135cd4 PM	220
	221	err1:
	222	if (priv->expr != NULL)
	223	nft_expr_destroy(ctx, priv->expr);
	224	return err;
22fe54d5 PM	225	}
	226
	227	static void nft_dynset_destroy(const struct nft_ctx *ctx,
	228	const struct nft_expr *expr)
	229	{
	230	struct nft_dynset *priv = nft_expr_priv(expr);
	231
	232	nf_tables_unbind_set(ctx, priv->set, &priv->binding);
3e135cd4 PM	233	if (priv->expr != NULL)
3e135cd4 PM	234	nft_expr_destroy(ctx, priv->expr);
22fe54d5 PM	235	}
	236
	237	static int nft_dynset_dump(struct sk_buff skb, const struct nft_expr expr)
	238	{
	239	const struct nft_dynset *priv = nft_expr_priv(expr);
dbd2be06	240	u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
22fe54d5	241
b1c96ed3	242	if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
22fe54d5 PM	243	goto nla_put_failure;
22fe54d5 PM	244	if (priv->set->flags & NFT_SET_MAP &&
b1c96ed3	245	nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
22fe54d5 PM	246	goto nla_put_failure;
	247	if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
	248	goto nla_put_failure;
	249	if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
	250	goto nla_put_failure;
a8b1e36d AP	251	if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
a8b1e36d AP	252	cpu_to_be64(jiffies_to_msecs(priv->timeout)),
b46f6ded	253	NFTA_DYNSET_PAD))
22fe54d5	254	goto nla_put_failure;
3e135cd4 PM	255	if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
3e135cd4 PM	256	goto nla_put_failure;
dbd2be06 PNA	257	if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
dbd2be06 PNA	258	goto nla_put_failure;
22fe54d5 PM	259	return 0;
	260
	261	nla_put_failure:
	262	return -1;
	263	}
	264
22fe54d5 PM	265	static const struct nft_expr_ops nft_dynset_ops = {
	266	.type = &nft_dynset_type,
	267	.size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
	268	.eval = nft_dynset_eval,
	269	.init = nft_dynset_init,
	270	.destroy = nft_dynset_destroy,
	271	.dump = nft_dynset_dump,
	272	};
	273
4e24877e	274	struct nft_expr_type nft_dynset_type __read_mostly = {
22fe54d5 PM	275	.name = "dynset",
	276	.ops = &nft_dynset_ops,
	277	.policy = nft_dynset_policy,
	278	.maxattr = NFTA_DYNSET_MAX,
	279	.owner = THIS_MODULE,
	280	};