[linux-2.6-block.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_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);
		return;
	}
out:
	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 },
};

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 = 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);

	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(priv->timeout)))
		goto nla_put_failure;
	if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
		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;
3e135cd4	26	struct nft_expr *expr;
22fe54d5 PM	27	struct nft_set_binding binding;
	28	};
	29
	30	static void nft_dynset_new(struct nft_set set, const struct nft_expr *expr,
a55e22e9	31	struct nft_regs *regs)
22fe54d5 PM	32	{
22fe54d5 PM	33	const struct nft_dynset *priv = nft_expr_priv(expr);
3e135cd4	34	struct nft_set_ext *ext;
22fe54d5 PM	35	u64 timeout;
	36	void *elem;
	37
	38	if (set->size && !atomic_add_unless(&set->nelems, 1, set->size))
	39	return NULL;
	40
	41	timeout = priv->timeout ? : set->timeout;
	42	elem = nft_set_elem_init(set, &priv->tmpl,
a55e22e9 PM	43	&regs->data[priv->sreg_key],
a55e22e9 PM	44	&regs->data[priv->sreg_data],
22fe54d5 PM	45	timeout, GFP_ATOMIC);
	46	if (elem == NULL) {
	47	if (set->size)
	48	atomic_dec(&set->nelems);
3e135cd4	49	return NULL;
22fe54d5	50	}
3e135cd4 PM	51
3e135cd4 PM	52	ext = nft_set_elem_ext(set, elem);
086f3321 PNA	53	if (priv->expr != NULL &&
	54	nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0)
	55	return NULL;
3e135cd4	56
22fe54d5 PM	57	return elem;
	58	}
	59
	60	static void nft_dynset_eval(const struct nft_expr *expr,
a55e22e9	61	struct nft_regs *regs,
22fe54d5 PM	62	const struct nft_pktinfo *pkt)
	63	{
	64	const struct nft_dynset *priv = nft_expr_priv(expr);
	65	struct nft_set *set = priv->set;
	66	const struct nft_set_ext *ext;
3e135cd4	67	const struct nft_expr *sexpr;
22fe54d5 PM	68	u64 timeout;
22fe54d5 PM	69
a55e22e9 PM	70	if (set->ops->update(set, &regs->data[priv->sreg_key], nft_dynset_new,
a55e22e9 PM	71	expr, regs, &ext)) {
3e135cd4 PM	72	sexpr = NULL;
	73	if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR))
	74	sexpr = nft_set_ext_expr(ext);
	75
22fe54d5 PM	76	if (priv->op == NFT_DYNSET_OP_UPDATE &&
	77	nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
	78	timeout = priv->timeout ? : set->timeout;
	79	*nft_set_ext_expiration(ext) = jiffies + timeout;
3e135cd4 PM	80	} else if (sexpr == NULL)
3e135cd4 PM	81	goto out;
22fe54d5	82
3e135cd4 PM	83	if (sexpr != NULL)
	84	sexpr->ops->eval(sexpr, regs, pkt);
	85	return;
	86	}
	87	out:
a55e22e9	88	regs->verdict.code = NFT_BREAK;
22fe54d5 PM	89	}
	90
	91	static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
	92	[NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING },
	93	[NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
	94	[NFTA_DYNSET_OP] = { .type = NLA_U32 },
	95	[NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
	96	[NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
	97	[NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
3e135cd4	98	[NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
22fe54d5 PM	99	};
	100
	101	static int nft_dynset_init(const struct nft_ctx *ctx,
	102	const struct nft_expr *expr,
	103	const struct nlattr * const tb[])
	104	{
	105	struct nft_dynset *priv = nft_expr_priv(expr);
	106	struct nft_set *set;
	107	u64 timeout;
	108	int err;
	109
	110	if (tb[NFTA_DYNSET_SET_NAME] == NULL \|\|
	111	tb[NFTA_DYNSET_OP] == NULL \|\|
	112	tb[NFTA_DYNSET_SREG_KEY] == NULL)
	113	return -EINVAL;
	114
	115	set = nf_tables_set_lookup(ctx->table, tb[NFTA_DYNSET_SET_NAME]);
	116	if (IS_ERR(set)) {
	117	if (tb[NFTA_DYNSET_SET_ID])
	118	set = nf_tables_set_lookup_byid(ctx->net,
	119	tb[NFTA_DYNSET_SET_ID]);
	120	if (IS_ERR(set))
	121	return PTR_ERR(set);
	122	}
	123
	124	if (set->flags & NFT_SET_CONSTANT)
	125	return -EBUSY;
	126
	127	priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
	128	switch (priv->op) {
	129	case NFT_DYNSET_OP_ADD:
	130	break;
	131	case NFT_DYNSET_OP_UPDATE:
	132	if (!(set->flags & NFT_SET_TIMEOUT))
	133	return -EOPNOTSUPP;
	134	break;
	135	default:
	136	return -EOPNOTSUPP;
	137	}
	138
	139	timeout = 0;
	140	if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
	141	if (!(set->flags & NFT_SET_TIMEOUT))
	142	return -EINVAL;
	143	timeout = be64_to_cpu(nla_get_be64(tb[NFTA_DYNSET_TIMEOUT]));
	144	}
	145
b1c96ed3	146	priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]);
d07db988	147	err = nft_validate_register_load(priv->sreg_key, set->klen);;
22fe54d5 PM	148	if (err < 0)
	149	return err;
	150
	151	if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
	152	if (!(set->flags & NFT_SET_MAP))
	153	return -EINVAL;
	154	if (set->dtype == NFT_DATA_VERDICT)
	155	return -EOPNOTSUPP;
	156
b1c96ed3	157	priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]);
d07db988	158	err = nft_validate_register_load(priv->sreg_data, set->dlen);
22fe54d5 PM	159	if (err < 0)
	160	return err;
	161	} else if (set->flags & NFT_SET_MAP)
	162	return -EINVAL;
	163
3e135cd4 PM	164	if (tb[NFTA_DYNSET_EXPR] != NULL) {
	165	if (!(set->flags & NFT_SET_EVAL))
	166	return -EINVAL;
	167	if (!(set->flags & NFT_SET_ANONYMOUS))
	168	return -EOPNOTSUPP;
	169
	170	priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]);
	171	if (IS_ERR(priv->expr))
	172	return PTR_ERR(priv->expr);
	173
	174	err = -EOPNOTSUPP;
	175	if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL))
	176	goto err1;
	177	} else if (set->flags & NFT_SET_EVAL)
	178	return -EINVAL;
	179
22fe54d5 PM	180	nft_set_ext_prepare(&priv->tmpl);
	181	nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
	182	if (set->flags & NFT_SET_MAP)
	183	nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
3e135cd4 PM	184	if (priv->expr != NULL)
	185	nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
	186	priv->expr->ops->size);
22fe54d5 PM	187	if (set->flags & NFT_SET_TIMEOUT) {
	188	if (timeout \|\| set->timeout)
	189	nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
	190	}
	191
	192	priv->timeout = timeout;
	193
	194	err = nf_tables_bind_set(ctx, set, &priv->binding);
	195	if (err < 0)
3e135cd4	196	goto err1;
22fe54d5 PM	197
	198	priv->set = set;
	199	return 0;
3e135cd4 PM	200
	201	err1:
	202	if (priv->expr != NULL)
	203	nft_expr_destroy(ctx, priv->expr);
	204	return err;
22fe54d5 PM	205	}
	206
	207	static void nft_dynset_destroy(const struct nft_ctx *ctx,
	208	const struct nft_expr *expr)
	209	{
	210	struct nft_dynset *priv = nft_expr_priv(expr);
	211
	212	nf_tables_unbind_set(ctx, priv->set, &priv->binding);
3e135cd4 PM	213	if (priv->expr != NULL)
3e135cd4 PM	214	nft_expr_destroy(ctx, priv->expr);
22fe54d5 PM	215	}
	216
	217	static int nft_dynset_dump(struct sk_buff skb, const struct nft_expr expr)
	218	{
	219	const struct nft_dynset *priv = nft_expr_priv(expr);
	220
b1c96ed3	221	if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
22fe54d5 PM	222	goto nla_put_failure;
22fe54d5 PM	223	if (priv->set->flags & NFT_SET_MAP &&
b1c96ed3	224	nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
22fe54d5 PM	225	goto nla_put_failure;
	226	if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
	227	goto nla_put_failure;
	228	if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
	229	goto nla_put_failure;
	230	if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT, cpu_to_be64(priv->timeout)))
	231	goto nla_put_failure;
3e135cd4 PM	232	if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
3e135cd4 PM	233	goto nla_put_failure;
22fe54d5 PM	234	return 0;
	235
	236	nla_put_failure:
	237	return -1;
	238	}
	239
	240	static struct nft_expr_type nft_dynset_type;
	241	static const struct nft_expr_ops nft_dynset_ops = {
	242	.type = &nft_dynset_type,
	243	.size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
	244	.eval = nft_dynset_eval,
	245	.init = nft_dynset_init,
	246	.destroy = nft_dynset_destroy,
	247	.dump = nft_dynset_dump,
	248	};
	249
	250	static struct nft_expr_type nft_dynset_type __read_mostly = {
	251	.name = "dynset",
	252	.ops = &nft_dynset_ops,
	253	.policy = nft_dynset_policy,
	254	.maxattr = NFTA_DYNSET_MAX,
	255	.owner = THIS_MODULE,
	256	};
	257
	258	int __init nft_dynset_module_init(void)
	259	{
	260	return nft_register_expr(&nft_dynset_type);
	261	}
	262
	263	void nft_dynset_module_exit(void)
	264	{
	265	nft_unregister_expr(&nft_dynset_type);
	266	}