[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;
	u64				timeout;
	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);
	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 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;
	u64 timeout;

	if (set->ops->update(set, &regs->data[priv->sreg_key], nft_dynset_new,
			     expr, regs, &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;
			return;
		}
	}

	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 },
};

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);
	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;

	set = nf_tables_set_lookup(ctx->table, tb[NFTA_DYNSET_SET_NAME]);
	if (IS_ERR(set)) {
		if (tb[NFTA_DYNSET_SET_ID])
			set = nf_tables_set_lookup_byid(ctx->net,
							tb[NFTA_DYNSET_SET_ID]);
		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 = be64_to_cpu(nla_get_be64(tb[NFTA_DYNSET_TIMEOUT]));
	}

	priv->sreg_key = ntohl(nla_get_be32(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 = ntohl(nla_get_be32(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;

	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 (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)
		return err;

	priv->set = set;
	return 0;
}

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);
}

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

	if (nla_put_be32(skb, NFTA_DYNSET_SREG_KEY, htonl(priv->sreg_key)))
		goto nla_put_failure;
	if (priv->set->flags & NFT_SET_MAP &&
	    nla_put_be32(skb, NFTA_DYNSET_SREG_DATA, htonl(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(priv->timeout)))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -1;
}

static struct nft_expr_type nft_dynset_type;
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,
};

static 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,
};

int __init nft_dynset_module_init(void)
{
	return nft_register_expr(&nft_dynset_type);
}

void nft_dynset_module_exit(void)
{
	nft_unregister_expr(&nft_dynset_type);
}
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;
	25	u64 timeout;
	26	struct nft_set_binding binding;
	27	};
	28
	29	static void nft_dynset_new(struct nft_set set, const struct nft_expr *expr,
a55e22e9	30	struct nft_regs *regs)
22fe54d5 PM	31	{
	32	const struct nft_dynset *priv = nft_expr_priv(expr);
	33	u64 timeout;
	34	void *elem;
	35
	36	if (set->size && !atomic_add_unless(&set->nelems, 1, set->size))
	37	return NULL;
	38
	39	timeout = priv->timeout ? : set->timeout;
	40	elem = nft_set_elem_init(set, &priv->tmpl,
a55e22e9 PM	41	&regs->data[priv->sreg_key],
a55e22e9 PM	42	&regs->data[priv->sreg_data],
22fe54d5 PM	43	timeout, GFP_ATOMIC);
	44	if (elem == NULL) {
	45	if (set->size)
	46	atomic_dec(&set->nelems);
	47	}
	48	return elem;
	49	}
	50
	51	static void nft_dynset_eval(const struct nft_expr *expr,
a55e22e9	52	struct nft_regs *regs,
22fe54d5 PM	53	const struct nft_pktinfo *pkt)
	54	{
	55	const struct nft_dynset *priv = nft_expr_priv(expr);
	56	struct nft_set *set = priv->set;
	57	const struct nft_set_ext *ext;
	58	u64 timeout;
	59
a55e22e9 PM	60	if (set->ops->update(set, &regs->data[priv->sreg_key], nft_dynset_new,
a55e22e9 PM	61	expr, regs, &ext)) {
22fe54d5 PM	62	if (priv->op == NFT_DYNSET_OP_UPDATE &&
	63	nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
	64	timeout = priv->timeout ? : set->timeout;
	65	*nft_set_ext_expiration(ext) = jiffies + timeout;
	66	return;
	67	}
	68	}
	69
a55e22e9	70	regs->verdict.code = NFT_BREAK;
22fe54d5 PM	71	}
	72
	73	static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
	74	[NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING },
	75	[NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
	76	[NFTA_DYNSET_OP] = { .type = NLA_U32 },
	77	[NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
	78	[NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
	79	[NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
	80	};
	81
	82	static int nft_dynset_init(const struct nft_ctx *ctx,
	83	const struct nft_expr *expr,
	84	const struct nlattr * const tb[])
	85	{
	86	struct nft_dynset *priv = nft_expr_priv(expr);
	87	struct nft_set *set;
	88	u64 timeout;
	89	int err;
	90
	91	if (tb[NFTA_DYNSET_SET_NAME] == NULL \|\|
	92	tb[NFTA_DYNSET_OP] == NULL \|\|
	93	tb[NFTA_DYNSET_SREG_KEY] == NULL)
	94	return -EINVAL;
	95
	96	set = nf_tables_set_lookup(ctx->table, tb[NFTA_DYNSET_SET_NAME]);
	97	if (IS_ERR(set)) {
	98	if (tb[NFTA_DYNSET_SET_ID])
	99	set = nf_tables_set_lookup_byid(ctx->net,
	100	tb[NFTA_DYNSET_SET_ID]);
	101	if (IS_ERR(set))
	102	return PTR_ERR(set);
	103	}
	104
	105	if (set->flags & NFT_SET_CONSTANT)
	106	return -EBUSY;
	107
	108	priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
	109	switch (priv->op) {
	110	case NFT_DYNSET_OP_ADD:
	111	break;
	112	case NFT_DYNSET_OP_UPDATE:
	113	if (!(set->flags & NFT_SET_TIMEOUT))
	114	return -EOPNOTSUPP;
	115	break;
	116	default:
	117	return -EOPNOTSUPP;
	118	}
	119
	120	timeout = 0;
	121	if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
	122	if (!(set->flags & NFT_SET_TIMEOUT))
	123	return -EINVAL;
	124	timeout = be64_to_cpu(nla_get_be64(tb[NFTA_DYNSET_TIMEOUT]));
	125	}
	126
	127	priv->sreg_key = ntohl(nla_get_be32(tb[NFTA_DYNSET_SREG_KEY]));
d07db988	128	err = nft_validate_register_load(priv->sreg_key, set->klen);;
22fe54d5 PM	129	if (err < 0)
	130	return err;
	131
	132	if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
	133	if (!(set->flags & NFT_SET_MAP))
	134	return -EINVAL;
	135	if (set->dtype == NFT_DATA_VERDICT)
	136	return -EOPNOTSUPP;
	137
	138	priv->sreg_data = ntohl(nla_get_be32(tb[NFTA_DYNSET_SREG_DATA]));
d07db988	139	err = nft_validate_register_load(priv->sreg_data, set->dlen);
22fe54d5 PM	140	if (err < 0)
	141	return err;
	142	} else if (set->flags & NFT_SET_MAP)
	143	return -EINVAL;
	144
	145	nft_set_ext_prepare(&priv->tmpl);
	146	nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
	147	if (set->flags & NFT_SET_MAP)
	148	nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
	149	if (set->flags & NFT_SET_TIMEOUT) {
	150	if (timeout \|\| set->timeout)
	151	nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
	152	}
	153
	154	priv->timeout = timeout;
	155
	156	err = nf_tables_bind_set(ctx, set, &priv->binding);
	157	if (err < 0)
	158	return err;
	159
	160	priv->set = set;
	161	return 0;
	162	}
	163
	164	static void nft_dynset_destroy(const struct nft_ctx *ctx,
	165	const struct nft_expr *expr)
	166	{
	167	struct nft_dynset *priv = nft_expr_priv(expr);
	168
	169	nf_tables_unbind_set(ctx, priv->set, &priv->binding);
	170	}
	171
	172	static int nft_dynset_dump(struct sk_buff skb, const struct nft_expr expr)
	173	{
	174	const struct nft_dynset *priv = nft_expr_priv(expr);
	175
	176	if (nla_put_be32(skb, NFTA_DYNSET_SREG_KEY, htonl(priv->sreg_key)))
	177	goto nla_put_failure;
	178	if (priv->set->flags & NFT_SET_MAP &&
	179	nla_put_be32(skb, NFTA_DYNSET_SREG_DATA, htonl(priv->sreg_data)))
	180	goto nla_put_failure;
	181	if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
	182	goto nla_put_failure;
	183	if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
	184	goto nla_put_failure;
	185	if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT, cpu_to_be64(priv->timeout)))
	186	goto nla_put_failure;
	187	return 0;
	188
	189	nla_put_failure:
	190	return -1;
	191	}
	192
	193	static struct nft_expr_type nft_dynset_type;
	194	static const struct nft_expr_ops nft_dynset_ops = {
	195	.type = &nft_dynset_type,
	196	.size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
	197	.eval = nft_dynset_eval,
	198	.init = nft_dynset_init,
	199	.destroy = nft_dynset_destroy,
	200	.dump = nft_dynset_dump,
	201	};
	202
	203	static struct nft_expr_type nft_dynset_type __read_mostly = {
204	.name = "dynset",
205	.ops = &nft_dynset_ops,
206	.policy = nft_dynset_policy,
207	.maxattr = NFTA_DYNSET_MAX,
208	.owner = THIS_MODULE,
209	};
210
211	int __init nft_dynset_module_init(void)
212	{
213	return nft_register_expr(&nft_dynset_type);
214	}
215
216	void nft_dynset_module_exit(void)
217	{
218	nft_unregister_expr(&nft_dynset_type);
219	}