[linux-2.6-block.git] / net / netfilter / nft_cmp.c

/*
 * Copyright (c) 2008-2009 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.
 *
 * Development of this code funded by Astaro AG (http://www.astaro.com/)
 */

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

struct nft_cmp_expr {
	struct nft_data		data;
	enum nft_registers	sreg:8;
	u8			len;
	enum nft_cmp_ops	op:8;
};

static void nft_cmp_eval(const struct nft_expr *expr,
			 struct nft_regs *regs,
			 const struct nft_pktinfo *pkt)
{
	const struct nft_cmp_expr *priv = nft_expr_priv(expr);
	int d;

	d = memcmp(&regs->data[priv->sreg], &priv->data, priv->len);
	switch (priv->op) {
	case NFT_CMP_EQ:
		if (d != 0)
			goto mismatch;
		break;
	case NFT_CMP_NEQ:
		if (d == 0)
			goto mismatch;
		break;
	case NFT_CMP_LT:
		if (d == 0)
			goto mismatch;
	case NFT_CMP_LTE:
		if (d > 0)
			goto mismatch;
		break;
	case NFT_CMP_GT:
		if (d == 0)
			goto mismatch;
	case NFT_CMP_GTE:
		if (d < 0)
			goto mismatch;
		break;
	}
	return;

mismatch:
	regs->verdict.code = NFT_BREAK;
}

static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = {
	[NFTA_CMP_SREG]		= { .type = NLA_U32 },
	[NFTA_CMP_OP]		= { .type = NLA_U32 },
	[NFTA_CMP_DATA]		= { .type = NLA_NESTED },
};

static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
			const struct nlattr * const tb[])
{
	struct nft_cmp_expr *priv = nft_expr_priv(expr);
	struct nft_data_desc desc;
	int err;

	err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc,
			    tb[NFTA_CMP_DATA]);
	BUG_ON(err < 0);

	priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
	err = nft_validate_register_load(priv->sreg, desc.len);
	if (err < 0)
		return err;

	if (desc.len > U8_MAX)
		return -ERANGE;

	priv->op  = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
	priv->len = desc.len;
	return 0;
}

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

	if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
		goto nla_put_failure;
	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))
		goto nla_put_failure;

	if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
			  NFT_DATA_VALUE, priv->len) < 0)
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -1;
}

static struct nft_expr_type nft_cmp_type;
static const struct nft_expr_ops nft_cmp_ops = {
	.type		= &nft_cmp_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),
	.eval		= nft_cmp_eval,
	.init		= nft_cmp_init,
	.dump		= nft_cmp_dump,
};

static int nft_cmp_fast_init(const struct nft_ctx *ctx,
			     const struct nft_expr *expr,
			     const struct nlattr * const tb[])
{
	struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	struct nft_data_desc desc;
	struct nft_data data;
	u32 mask;
	int err;

	err = nft_data_init(NULL, &data, sizeof(data), &desc,
			    tb[NFTA_CMP_DATA]);
	BUG_ON(err < 0);

	priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
	err = nft_validate_register_load(priv->sreg, desc.len);
	if (err < 0)
		return err;

	desc.len *= BITS_PER_BYTE;
	mask = nft_cmp_fast_mask(desc.len);

	priv->data = data.data[0] & mask;
	priv->len  = desc.len;
	return 0;
}

static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
	const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	struct nft_data data;

	if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
		goto nla_put_failure;
	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(NFT_CMP_EQ)))
		goto nla_put_failure;

	data.data[0] = priv->data;
	if (nft_data_dump(skb, NFTA_CMP_DATA, &data,
			  NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0)
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -1;
}

const struct nft_expr_ops nft_cmp_fast_ops = {
	.type		= &nft_cmp_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),
	.eval		= NULL,	/* inlined */
	.init		= nft_cmp_fast_init,
	.dump		= nft_cmp_fast_dump,
};

static const struct nft_expr_ops *
nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])
{
	struct nft_data_desc desc;
	struct nft_data data;
	enum nft_cmp_ops op;
	int err;

	if (tb[NFTA_CMP_SREG] == NULL ||
	    tb[NFTA_CMP_OP] == NULL ||
	    tb[NFTA_CMP_DATA] == NULL)
		return ERR_PTR(-EINVAL);

	op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
	switch (op) {
	case NFT_CMP_EQ:
	case NFT_CMP_NEQ:
	case NFT_CMP_LT:
	case NFT_CMP_LTE:
	case NFT_CMP_GT:
	case NFT_CMP_GTE:
		break;
	default:
		return ERR_PTR(-EINVAL);
	}

	err = nft_data_init(NULL, &data, sizeof(data), &desc,
			    tb[NFTA_CMP_DATA]);
	if (err < 0)
		return ERR_PTR(err);

	if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ)
		return &nft_cmp_fast_ops;
	else
		return &nft_cmp_ops;
}

static struct nft_expr_type nft_cmp_type __read_mostly = {
	.name		= "cmp",
	.select_ops	= nft_cmp_select_ops,
	.policy		= nft_cmp_policy,
	.maxattr	= NFTA_CMP_MAX,
	.owner		= THIS_MODULE,
};

int __init nft_cmp_module_init(void)
{
	return nft_register_expr(&nft_cmp_type);
}

void nft_cmp_module_exit(void)
{
	nft_unregister_expr(&nft_cmp_type);
}
Commit	Line	Data
96518518	1	/*
ef1f7df9	2	* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
96518518 PM	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	* Development of this code funded by Astaro AG (http://www.astaro.com/)
	9	*/
	10
	11	#include <linux/kernel.h>
	12	#include <linux/init.h>
	13	#include <linux/module.h>
	14	#include <linux/netlink.h>
	15	#include <linux/netfilter.h>
	16	#include <linux/netfilter/nf_tables.h>
	17	#include <net/netfilter/nf_tables_core.h>
	18	#include <net/netfilter/nf_tables.h>
	19
	20	struct nft_cmp_expr {
	21	struct nft_data data;
	22	enum nft_registers sreg:8;
	23	u8 len;
	24	enum nft_cmp_ops op:8;
	25	};
	26
	27	static void nft_cmp_eval(const struct nft_expr *expr,
a55e22e9	28	struct nft_regs *regs,
96518518 PM	29	const struct nft_pktinfo *pkt)
	30	{
	31	const struct nft_cmp_expr *priv = nft_expr_priv(expr);
	32	int d;
	33
e562d860	34	d = memcmp(&regs->data[priv->sreg], &priv->data, priv->len);
96518518 PM	35	switch (priv->op) {
	36	case NFT_CMP_EQ:
	37	if (d != 0)
	38	goto mismatch;
	39	break;
	40	case NFT_CMP_NEQ:
	41	if (d == 0)
	42	goto mismatch;
	43	break;
	44	case NFT_CMP_LT:
	45	if (d == 0)
	46	goto mismatch;
	47	case NFT_CMP_LTE:
	48	if (d > 0)
	49	goto mismatch;
	50	break;
	51	case NFT_CMP_GT:
	52	if (d == 0)
	53	goto mismatch;
	54	case NFT_CMP_GTE:
	55	if (d < 0)
	56	goto mismatch;
	57	break;
	58	}
	59	return;
	60
	61	mismatch:
a55e22e9	62	regs->verdict.code = NFT_BREAK;
96518518 PM	63	}
	64
	65	static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = {
	66	[NFTA_CMP_SREG] = { .type = NLA_U32 },
	67	[NFTA_CMP_OP] = { .type = NLA_U32 },
	68	[NFTA_CMP_DATA] = { .type = NLA_NESTED },
	69	};
	70
	71	static int nft_cmp_init(const struct nft_ctx ctx, const struct nft_expr expr,
	72	const struct nlattr * const tb[])
	73	{
	74	struct nft_cmp_expr *priv = nft_expr_priv(expr);
	75	struct nft_data_desc desc;
	76	int err;
	77
d0a11fc3 PM	78	err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc,
d0a11fc3 PM	79	tb[NFTA_CMP_DATA]);
cb7dbfd0	80	BUG_ON(err < 0);
96518518	81
b1c96ed3	82	priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
d07db988 PM	83	err = nft_validate_register_load(priv->sreg, desc.len);
	84	if (err < 0)
	85	return err;
	86
36b701fa LGL	87	if (desc.len > U8_MAX)
	88	return -ERANGE;
	89
d07db988	90	priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
96518518 PM	91	priv->len = desc.len;
	92	return 0;
	93	}
	94
	95	static int nft_cmp_dump(struct sk_buff skb, const struct nft_expr expr)
	96	{
	97	const struct nft_cmp_expr *priv = nft_expr_priv(expr);
	98
b1c96ed3	99	if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
96518518 PM	100	goto nla_put_failure;
	101	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))
	102	goto nla_put_failure;
	103
	104	if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
	105	NFT_DATA_VALUE, priv->len) < 0)
	106	goto nla_put_failure;
	107	return 0;
	108
	109	nla_put_failure:
	110	return -1;
	111	}
	112
ef1f7df9 PM	113	static struct nft_expr_type nft_cmp_type;
	114	static const struct nft_expr_ops nft_cmp_ops = {
	115	.type = &nft_cmp_type,
96518518	116	.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),
96518518 PM	117	.eval = nft_cmp_eval,
	118	.init = nft_cmp_init,
	119	.dump = nft_cmp_dump,
ef1f7df9 PM	120	};
ef1f7df9 PM	121
cb7dbfd0 PM	122	static int nft_cmp_fast_init(const struct nft_ctx *ctx,
	123	const struct nft_expr *expr,
	124	const struct nlattr * const tb[])
	125	{
	126	struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	127	struct nft_data_desc desc;
	128	struct nft_data data;
	129	u32 mask;
	130	int err;
	131
d0a11fc3 PM	132	err = nft_data_init(NULL, &data, sizeof(data), &desc,
d0a11fc3 PM	133	tb[NFTA_CMP_DATA]);
cb7dbfd0	134	BUG_ON(err < 0);
cb7dbfd0	135
b1c96ed3	136	priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
d07db988 PM	137	err = nft_validate_register_load(priv->sreg, desc.len);
	138	if (err < 0)
	139	return err;
	140
	141	desc.len *= BITS_PER_BYTE;
b855d416	142	mask = nft_cmp_fast_mask(desc.len);
d07db988	143
cb7dbfd0 PM	144	priv->data = data.data[0] & mask;
	145	priv->len = desc.len;
	146	return 0;
	147	}
	148
	149	static int nft_cmp_fast_dump(struct sk_buff skb, const struct nft_expr expr)
	150	{
	151	const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	152	struct nft_data data;
	153
b1c96ed3	154	if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
cb7dbfd0 PM	155	goto nla_put_failure;
	156	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(NFT_CMP_EQ)))
	157	goto nla_put_failure;
	158
	159	data.data[0] = priv->data;
	160	if (nft_data_dump(skb, NFTA_CMP_DATA, &data,
	161	NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0)
	162	goto nla_put_failure;
	163	return 0;
	164
	165	nla_put_failure:
	166	return -1;
	167	}
	168
	169	const struct nft_expr_ops nft_cmp_fast_ops = {
	170	.type = &nft_cmp_type,
	171	.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),
	172	.eval = NULL, /* inlined */
	173	.init = nft_cmp_fast_init,
	174	.dump = nft_cmp_fast_dump,
	175	};
	176
0ca743a5 PNA	177	static const struct nft_expr_ops *
0ca743a5 PNA	178	nft_cmp_select_ops(const struct nft_ctx ctx, const struct nlattr const tb[])
cb7dbfd0 PM	179	{
	180	struct nft_data_desc desc;
	181	struct nft_data data;
cb7dbfd0 PM	182	enum nft_cmp_ops op;
	183	int err;
	184
	185	if (tb[NFTA_CMP_SREG] == NULL \|\|
	186	tb[NFTA_CMP_OP] == NULL \|\|
	187	tb[NFTA_CMP_DATA] == NULL)
	188	return ERR_PTR(-EINVAL);
	189
cb7dbfd0 PM	190	op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
	191	switch (op) {
	192	case NFT_CMP_EQ:
	193	case NFT_CMP_NEQ:
	194	case NFT_CMP_LT:
	195	case NFT_CMP_LTE:
	196	case NFT_CMP_GT:
	197	case NFT_CMP_GTE:
	198	break;
	199	default:
	200	return ERR_PTR(-EINVAL);
	201	}
	202
d0a11fc3 PM	203	err = nft_data_init(NULL, &data, sizeof(data), &desc,
d0a11fc3 PM	204	tb[NFTA_CMP_DATA]);
cb7dbfd0 PM	205	if (err < 0)
	206	return ERR_PTR(err);
	207
	208	if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ)
	209	return &nft_cmp_fast_ops;
	210	else
	211	return &nft_cmp_ops;
	212	}
	213
ef1f7df9 PM	214	static struct nft_expr_type nft_cmp_type __read_mostly = {
ef1f7df9 PM	215	.name = "cmp",
cb7dbfd0	216	.select_ops = nft_cmp_select_ops,
96518518 PM	217	.policy = nft_cmp_policy,
96518518 PM	218	.maxattr = NFTA_CMP_MAX,
ef1f7df9	219	.owner = THIS_MODULE,
96518518 PM	220	};
	221
	222	int __init nft_cmp_module_init(void)
	223	{
ef1f7df9	224	return nft_register_expr(&nft_cmp_type);
96518518 PM	225	}
	226
	227	void nft_cmp_module_exit(void)
	228	{
ef1f7df9	229	nft_unregister_expr(&nft_cmp_type);
96518518	230	}