[mirror_ubuntu-artful-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) {
		if (set->size)
			atomic_dec(&set->nelems);
		return NULL;
	}

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

	return elem;
}

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;
		} else if (sexpr == NULL)
			goto out;

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

		if (priv->invert)
			regs->verdict.code = NFT_BREAK;
		return;
	}
out:
	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 },
	[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 = nf_tables_set_lookup(ctx->table, tb[NFTA_DYNSET_SET_NAME],
				   genmask);
	if (IS_ERR(set)) {
		if (tb[NFTA_DYNSET_SET_ID])
			set = nf_tables_set_lookup_byid(ctx->net,
							tb[NFTA_DYNSET_SET_ID],
							genmask);
		if (IS_ERR(set))
			return PTR_ERR(set);
	}

	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 PM	46	timeout, GFP_ATOMIC);
	47	if (elem == NULL) {
	48	if (set->size)
	49	atomic_dec(&set->nelems);
3e135cd4	50	return NULL;
22fe54d5	51	}
3e135cd4 PM	52
3e135cd4 PM	53	ext = nft_set_elem_ext(set, elem);
086f3321 PNA	54	if (priv->expr != NULL &&
	55	nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0)
	56	return NULL;
3e135cd4	57
22fe54d5 PM	58	return elem;
	59	}
	60
	61	static void nft_dynset_eval(const struct nft_expr *expr,
a55e22e9	62	struct nft_regs *regs,
22fe54d5 PM	63	const struct nft_pktinfo *pkt)
	64	{
	65	const struct nft_dynset *priv = nft_expr_priv(expr);
	66	struct nft_set *set = priv->set;
	67	const struct nft_set_ext *ext;
3e135cd4	68	const struct nft_expr *sexpr;
22fe54d5 PM	69	u64 timeout;
22fe54d5 PM	70
a55e22e9 PM	71	if (set->ops->update(set, &regs->data[priv->sreg_key], nft_dynset_new,
a55e22e9 PM	72	expr, regs, &ext)) {
3e135cd4 PM	73	sexpr = NULL;
	74	if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR))
	75	sexpr = nft_set_ext_expr(ext);
	76
22fe54d5 PM	77	if (priv->op == NFT_DYNSET_OP_UPDATE &&
	78	nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
	79	timeout = priv->timeout ? : set->timeout;
	80	*nft_set_ext_expiration(ext) = jiffies + timeout;
3e135cd4 PM	81	} else if (sexpr == NULL)
3e135cd4 PM	82	goto out;
22fe54d5	83
3e135cd4 PM	84	if (sexpr != NULL)
3e135cd4 PM	85	sexpr->ops->eval(sexpr, regs, pkt);
dbd2be06 PNA	86
	87	if (priv->invert)
	88	regs->verdict.code = NFT_BREAK;
3e135cd4 PM	89	return;
	90	}
	91	out:
dbd2be06 PNA	92	if (!priv->invert)
dbd2be06 PNA	93	regs->verdict.code = NFT_BREAK;
22fe54d5 PM	94	}
	95
	96	static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
	97	[NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING },
	98	[NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
	99	[NFTA_DYNSET_OP] = { .type = NLA_U32 },
	100	[NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
	101	[NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
	102	[NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
3e135cd4	103	[NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
dbd2be06	104	[NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
22fe54d5 PM	105	};
	106
	107	static int nft_dynset_init(const struct nft_ctx *ctx,
	108	const struct nft_expr *expr,
	109	const struct nlattr * const tb[])
	110	{
	111	struct nft_dynset *priv = nft_expr_priv(expr);
37a9cc52	112	u8 genmask = nft_genmask_next(ctx->net);
22fe54d5 PM	113	struct nft_set *set;
	114	u64 timeout;
	115	int err;
	116
	117	if (tb[NFTA_DYNSET_SET_NAME] == NULL \|\|
	118	tb[NFTA_DYNSET_OP] == NULL \|\|
	119	tb[NFTA_DYNSET_SREG_KEY] == NULL)
	120	return -EINVAL;
	121
dbd2be06 PNA	122	if (tb[NFTA_DYNSET_FLAGS]) {
	123	u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
	124
	125	if (flags & ~NFT_DYNSET_F_INV)
	126	return -EINVAL;
	127	if (flags & NFT_DYNSET_F_INV)
	128	priv->invert = true;
	129	}
	130
37a9cc52 PNA	131	set = nf_tables_set_lookup(ctx->table, tb[NFTA_DYNSET_SET_NAME],
37a9cc52 PNA	132	genmask);
22fe54d5 PM	133	if (IS_ERR(set)) {
	134	if (tb[NFTA_DYNSET_SET_ID])
	135	set = nf_tables_set_lookup_byid(ctx->net,
37a9cc52 PNA	136	tb[NFTA_DYNSET_SET_ID],
37a9cc52 PNA	137	genmask);
22fe54d5 PM	138	if (IS_ERR(set))
	139	return PTR_ERR(set);
	140	}
	141
	142	if (set->flags & NFT_SET_CONSTANT)
	143	return -EBUSY;
	144
	145	priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
	146	switch (priv->op) {
	147	case NFT_DYNSET_OP_ADD:
	148	break;
	149	case NFT_DYNSET_OP_UPDATE:
	150	if (!(set->flags & NFT_SET_TIMEOUT))
	151	return -EOPNOTSUPP;
	152	break;
	153	default:
	154	return -EOPNOTSUPP;
	155	}
	156
	157	timeout = 0;
	158	if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
	159	if (!(set->flags & NFT_SET_TIMEOUT))
	160	return -EINVAL;
a8b1e36d AP	161	timeout = msecs_to_jiffies(be64_to_cpu(nla_get_be64(
a8b1e36d AP	162	tb[NFTA_DYNSET_TIMEOUT])));
22fe54d5 PM	163	}
22fe54d5 PM	164
b1c96ed3	165	priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]);
d07db988	166	err = nft_validate_register_load(priv->sreg_key, set->klen);;
22fe54d5 PM	167	if (err < 0)
	168	return err;
	169
	170	if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
	171	if (!(set->flags & NFT_SET_MAP))
	172	return -EINVAL;
	173	if (set->dtype == NFT_DATA_VERDICT)
	174	return -EOPNOTSUPP;
	175
b1c96ed3	176	priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]);
d07db988	177	err = nft_validate_register_load(priv->sreg_data, set->dlen);
22fe54d5 PM	178	if (err < 0)
	179	return err;
	180	} else if (set->flags & NFT_SET_MAP)
	181	return -EINVAL;
	182
3e135cd4 PM	183	if (tb[NFTA_DYNSET_EXPR] != NULL) {
	184	if (!(set->flags & NFT_SET_EVAL))
	185	return -EINVAL;
	186	if (!(set->flags & NFT_SET_ANONYMOUS))
	187	return -EOPNOTSUPP;
	188
	189	priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]);
	190	if (IS_ERR(priv->expr))
	191	return PTR_ERR(priv->expr);
	192
	193	err = -EOPNOTSUPP;
	194	if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL))
	195	goto err1;
	196	} else if (set->flags & NFT_SET_EVAL)
	197	return -EINVAL;
	198
22fe54d5 PM	199	nft_set_ext_prepare(&priv->tmpl);
	200	nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
	201	if (set->flags & NFT_SET_MAP)
	202	nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
3e135cd4 PM	203	if (priv->expr != NULL)
	204	nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
	205	priv->expr->ops->size);
22fe54d5 PM	206	if (set->flags & NFT_SET_TIMEOUT) {
	207	if (timeout \|\| set->timeout)
	208	nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
	209	}
	210
	211	priv->timeout = timeout;
	212
	213	err = nf_tables_bind_set(ctx, set, &priv->binding);
	214	if (err < 0)
3e135cd4	215	goto err1;
22fe54d5 PM	216
	217	priv->set = set;
	218	return 0;
3e135cd4 PM	219
	220	err1:
	221	if (priv->expr != NULL)
	222	nft_expr_destroy(ctx, priv->expr);
	223	return err;
22fe54d5 PM	224	}
	225
	226	static void nft_dynset_destroy(const struct nft_ctx *ctx,
	227	const struct nft_expr *expr)
	228	{
	229	struct nft_dynset *priv = nft_expr_priv(expr);
	230
	231	nf_tables_unbind_set(ctx, priv->set, &priv->binding);
3e135cd4 PM	232	if (priv->expr != NULL)
3e135cd4 PM	233	nft_expr_destroy(ctx, priv->expr);
22fe54d5 PM	234	}
	235
	236	static int nft_dynset_dump(struct sk_buff skb, const struct nft_expr expr)
	237	{
	238	const struct nft_dynset *priv = nft_expr_priv(expr);
dbd2be06	239	u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
22fe54d5	240
b1c96ed3	241	if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
22fe54d5 PM	242	goto nla_put_failure;
22fe54d5 PM	243	if (priv->set->flags & NFT_SET_MAP &&
b1c96ed3	244	nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
22fe54d5 PM	245	goto nla_put_failure;
	246	if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
	247	goto nla_put_failure;
	248	if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
	249	goto nla_put_failure;
a8b1e36d AP	250	if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
a8b1e36d AP	251	cpu_to_be64(jiffies_to_msecs(priv->timeout)),
b46f6ded	252	NFTA_DYNSET_PAD))
22fe54d5	253	goto nla_put_failure;
3e135cd4 PM	254	if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
3e135cd4 PM	255	goto nla_put_failure;
dbd2be06 PNA	256	if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
dbd2be06 PNA	257	goto nla_put_failure;
22fe54d5 PM	258	return 0;
	259
	260	nla_put_failure:
	261	return -1;
	262	}
	263
22fe54d5 PM	264	static const struct nft_expr_ops nft_dynset_ops = {
	265	.type = &nft_dynset_type,
	266	.size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
	267	.eval = nft_dynset_eval,
	268	.init = nft_dynset_init,
	269	.destroy = nft_dynset_destroy,
	270	.dump = nft_dynset_dump,
	271	};
	272
4e24877e	273	struct nft_expr_type nft_dynset_type __read_mostly = {
22fe54d5 PM	274	.name = "dynset",
	275	.ops = &nft_dynset_ops,
	276	.policy = nft_dynset_policy,
	277	.maxattr = NFTA_DYNSET_MAX,
	278	.owner = THIS_MODULE,
	279	};