[deliverable/linux.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 = nft_data_cmp(&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, &desc, tb[NFTA_CMP_DATA]);
	BUG_ON(err < 0);

	priv->sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG]));
	err = nft_validate_register_load(priv->sreg, desc.len);
	if (err < 0)
		return err;

	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 (nla_put_be32(skb, NFTA_CMP_SREG, htonl(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, &desc, tb[NFTA_CMP_DATA]);
	BUG_ON(err < 0);

	priv->sreg = ntohl(nla_get_be32(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 (nla_put_be32(skb, NFTA_CMP_SREG, htonl(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, &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
a55e22e9	34	d = nft_data_cmp(&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
96518518	78	err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]);
cb7dbfd0	79	BUG_ON(err < 0);
96518518	80
d07db988 PM	81	priv->sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG]));
	82	err = nft_validate_register_load(priv->sreg, desc.len);
	83	if (err < 0)
	84	return err;
	85
	86	priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
96518518 PM	87	priv->len = desc.len;
	88	return 0;
	89	}
	90
	91	static int nft_cmp_dump(struct sk_buff skb, const struct nft_expr expr)
	92	{
	93	const struct nft_cmp_expr *priv = nft_expr_priv(expr);
	94
	95	if (nla_put_be32(skb, NFTA_CMP_SREG, htonl(priv->sreg)))
	96	goto nla_put_failure;
	97	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))
	98	goto nla_put_failure;
	99
	100	if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
	101	NFT_DATA_VALUE, priv->len) < 0)
	102	goto nla_put_failure;
	103	return 0;
	104
	105	nla_put_failure:
	106	return -1;
	107	}
	108
ef1f7df9 PM	109	static struct nft_expr_type nft_cmp_type;
	110	static const struct nft_expr_ops nft_cmp_ops = {
	111	.type = &nft_cmp_type,
96518518	112	.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),
96518518 PM	113	.eval = nft_cmp_eval,
	114	.init = nft_cmp_init,
	115	.dump = nft_cmp_dump,
ef1f7df9 PM	116	};
ef1f7df9 PM	117
cb7dbfd0 PM	118	static int nft_cmp_fast_init(const struct nft_ctx *ctx,
	119	const struct nft_expr *expr,
	120	const struct nlattr * const tb[])
	121	{
	122	struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	123	struct nft_data_desc desc;
	124	struct nft_data data;
	125	u32 mask;
	126	int err;
	127
cb7dbfd0 PM	128	err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]);
cb7dbfd0 PM	129	BUG_ON(err < 0);
cb7dbfd0	130
d07db988 PM	131	priv->sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG]));
	132	err = nft_validate_register_load(priv->sreg, desc.len);
	133	if (err < 0)
	134	return err;
	135
	136	desc.len *= BITS_PER_BYTE;
b855d416	137	mask = nft_cmp_fast_mask(desc.len);
d07db988	138
cb7dbfd0 PM	139	priv->data = data.data[0] & mask;
	140	priv->len = desc.len;
	141	return 0;
	142	}
	143
	144	static int nft_cmp_fast_dump(struct sk_buff skb, const struct nft_expr expr)
	145	{
	146	const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	147	struct nft_data data;
	148
	149	if (nla_put_be32(skb, NFTA_CMP_SREG, htonl(priv->sreg)))
	150	goto nla_put_failure;
	151	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(NFT_CMP_EQ)))
	152	goto nla_put_failure;
	153
	154	data.data[0] = priv->data;
	155	if (nft_data_dump(skb, NFTA_CMP_DATA, &data,
	156	NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0)
	157	goto nla_put_failure;
	158	return 0;
	159
	160	nla_put_failure:
	161	return -1;
	162	}
	163
	164	const struct nft_expr_ops nft_cmp_fast_ops = {
	165	.type = &nft_cmp_type,
	166	.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),
	167	.eval = NULL, /* inlined */
	168	.init = nft_cmp_fast_init,
	169	.dump = nft_cmp_fast_dump,
	170	};
	171
0ca743a5 PNA	172	static const struct nft_expr_ops *
0ca743a5 PNA	173	nft_cmp_select_ops(const struct nft_ctx ctx, const struct nlattr const tb[])
cb7dbfd0 PM	174	{
	175	struct nft_data_desc desc;
	176	struct nft_data data;
cb7dbfd0 PM	177	enum nft_cmp_ops op;
	178	int err;
	179
	180	if (tb[NFTA_CMP_SREG] == NULL \|\|
	181	tb[NFTA_CMP_OP] == NULL \|\|
	182	tb[NFTA_CMP_DATA] == NULL)
	183	return ERR_PTR(-EINVAL);
	184
cb7dbfd0 PM	185	op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
	186	switch (op) {
	187	case NFT_CMP_EQ:
	188	case NFT_CMP_NEQ:
	189	case NFT_CMP_LT:
	190	case NFT_CMP_LTE:
	191	case NFT_CMP_GT:
	192	case NFT_CMP_GTE:
	193	break;
	194	default:
	195	return ERR_PTR(-EINVAL);
	196	}
	197
	198	err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]);
	199	if (err < 0)
	200	return ERR_PTR(err);
	201
	202	if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ)
	203	return &nft_cmp_fast_ops;
	204	else
	205	return &nft_cmp_ops;
	206	}
	207
ef1f7df9 PM	208	static struct nft_expr_type nft_cmp_type __read_mostly = {
ef1f7df9 PM	209	.name = "cmp",
cb7dbfd0	210	.select_ops = nft_cmp_select_ops,
96518518 PM	211	.policy = nft_cmp_policy,
96518518 PM	212	.maxattr = NFTA_CMP_MAX,
ef1f7df9	213	.owner = THIS_MODULE,
96518518 PM	214	};
	215
	216	int __init nft_cmp_module_init(void)
	217	{
ef1f7df9	218	return nft_register_expr(&nft_cmp_type);
96518518 PM	219	}
	220
	221	void nft_cmp_module_exit(void)
	222	{
ef1f7df9	223	nft_unregister_expr(&nft_cmp_type);
96518518	224	}