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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
 *
 * 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_offload.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;
};

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;
		/* fall through */
	case NFT_CMP_LTE:
		if (d > 0)
			goto mismatch;
		break;
	case NFT_CMP_GT:
		if (d == 0)
			goto mismatch;
		/* fall through */
	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]);
	if (err < 0)
		return err;

	priv->sreg = nft_parse_register(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 (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 int __nft_cmp_offload(struct nft_offload_ctx *ctx,
			     struct nft_flow_rule *flow,
			     const struct nft_cmp_expr *priv)
{
	struct nft_offload_reg *reg = &ctx->regs[priv->sreg];
	u8 *mask = (u8 *)&flow->match.mask;
	u8 *key = (u8 *)&flow->match.key;

	if (priv->op != NFT_CMP_EQ)
		return -EOPNOTSUPP;

	memcpy(key + reg->offset, &priv->data, priv->len);
	memcpy(mask + reg->offset, &reg->mask, priv->len);

	flow->match.dissector.used_keys |= BIT(reg->key);
	flow->match.dissector.offset[reg->key] = reg->base_offset;

	nft_offload_update_dependency(ctx, &priv->data, priv->len);

	return 0;
}

static int nft_cmp_offload(struct nft_offload_ctx *ctx,
			   struct nft_flow_rule *flow,
			   const struct nft_expr *expr)
{
	const struct nft_cmp_expr *priv = nft_expr_priv(expr);

	return __nft_cmp_offload(ctx, flow, priv);
}

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,
	.offload	= nft_cmp_offload,
};

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]);
	if (err < 0)
		return err;

	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_offload(struct nft_offload_ctx *ctx,
				struct nft_flow_rule *flow,
				const struct nft_expr *expr)
{
	const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	struct nft_cmp_expr cmp = {
		.data	= {
			.data	= {
				[0] = priv->data,
			},
		},
		.sreg	= priv->sreg,
		.len	= priv->len / BITS_PER_BYTE,
		.op	= NFT_CMP_EQ,
	};

	return __nft_cmp_offload(ctx, flow, &cmp);
}

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,
	.offload	= nft_cmp_fast_offload,
};

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.type != NFT_DATA_VALUE) {
		err = -EINVAL;
		goto err1;
	}

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

	return &nft_cmp_ops;
err1:
	nft_data_release(&data, desc.type);
	return ERR_PTR(-EINVAL);
}

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,
};
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
96518518	2	/*
ef1f7df9	3	* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
96518518	4	*
96518518 PM	5	* Development of this code funded by Astaro AG (http://www.astaro.com/)
	6	*/
	7
	8	#include <linux/kernel.h>
	9	#include <linux/init.h>
	10	#include <linux/module.h>
	11	#include <linux/netlink.h>
	12	#include <linux/netfilter.h>
	13	#include <linux/netfilter/nf_tables.h>
	14	#include <net/netfilter/nf_tables_core.h>
c9626a2c	15	#include <net/netfilter/nf_tables_offload.h>
96518518 PM	16	#include <net/netfilter/nf_tables.h>
	17
	18	struct nft_cmp_expr {
	19	struct nft_data data;
	20	enum nft_registers sreg:8;
	21	u8 len;
	22	enum nft_cmp_ops op:8;
	23	};
	24
10870dd8 FW	25	void nft_cmp_eval(const struct nft_expr *expr,
	26	struct nft_regs *regs,
	27	const struct nft_pktinfo *pkt)
96518518 PM	28	{
	29	const struct nft_cmp_expr *priv = nft_expr_priv(expr);
	30	int d;
	31
e562d860	32	d = memcmp(&regs->data[priv->sreg], &priv->data, priv->len);
96518518 PM	33	switch (priv->op) {
	34	case NFT_CMP_EQ:
	35	if (d != 0)
	36	goto mismatch;
	37	break;
	38	case NFT_CMP_NEQ:
	39	if (d == 0)
	40	goto mismatch;
	41	break;
	42	case NFT_CMP_LT:
	43	if (d == 0)
	44	goto mismatch;
e8542dce	45	/* fall through */
96518518 PM	46	case NFT_CMP_LTE:
	47	if (d > 0)
	48	goto mismatch;
	49	break;
	50	case NFT_CMP_GT:
	51	if (d == 0)
	52	goto mismatch;
e8542dce	53	/* fall through */
96518518 PM	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]);
fa5950e4 FW	80	if (err < 0)
fa5950e4 FW	81	return err;
96518518	82
b1c96ed3	83	priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
d07db988 PM	84	err = nft_validate_register_load(priv->sreg, desc.len);
	85	if (err < 0)
	86	return err;
	87
	88	priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
96518518 PM	89	priv->len = desc.len;
	90	return 0;
	91	}
	92
	93	static int nft_cmp_dump(struct sk_buff skb, const struct nft_expr expr)
	94	{
	95	const struct nft_cmp_expr *priv = nft_expr_priv(expr);
	96
b1c96ed3	97	if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
96518518 PM	98	goto nla_put_failure;
	99	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))
	100	goto nla_put_failure;
	101
	102	if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
	103	NFT_DATA_VALUE, priv->len) < 0)
	104	goto nla_put_failure;
	105	return 0;
	106
	107	nla_put_failure:
	108	return -1;
	109	}
	110
c9626a2c PNA	111	static int __nft_cmp_offload(struct nft_offload_ctx *ctx,
	112	struct nft_flow_rule *flow,
	113	const struct nft_cmp_expr *priv)
	114	{
	115	struct nft_offload_reg *reg = &ctx->regs[priv->sreg];
	116	u8 mask = (u8 )&flow->match.mask;
	117	u8 key = (u8 )&flow->match.key;
	118
	119	if (priv->op != NFT_CMP_EQ)
	120	return -EOPNOTSUPP;
	121
	122	memcpy(key + reg->offset, &priv->data, priv->len);
	123	memcpy(mask + reg->offset, &reg->mask, priv->len);
	124
	125	flow->match.dissector.used_keys \|= BIT(reg->key);
	126	flow->match.dissector.offset[reg->key] = reg->base_offset;
	127
	128	nft_offload_update_dependency(ctx, &priv->data, priv->len);
	129
	130	return 0;
	131	}
	132
	133	static int nft_cmp_offload(struct nft_offload_ctx *ctx,
	134	struct nft_flow_rule *flow,
	135	const struct nft_expr *expr)
	136	{
	137	const struct nft_cmp_expr *priv = nft_expr_priv(expr);
	138
	139	return __nft_cmp_offload(ctx, flow, priv);
	140	}
	141
ef1f7df9 PM	142	static const struct nft_expr_ops nft_cmp_ops = {
ef1f7df9 PM	143	.type = &nft_cmp_type,
96518518	144	.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),
96518518 PM	145	.eval = nft_cmp_eval,
	146	.init = nft_cmp_init,
	147	.dump = nft_cmp_dump,
c9626a2c	148	.offload = nft_cmp_offload,
ef1f7df9 PM	149	};
ef1f7df9 PM	150
cb7dbfd0 PM	151	static int nft_cmp_fast_init(const struct nft_ctx *ctx,
	152	const struct nft_expr *expr,
	153	const struct nlattr * const tb[])
	154	{
	155	struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	156	struct nft_data_desc desc;
	157	struct nft_data data;
	158	u32 mask;
	159	int err;
	160
d0a11fc3 PM	161	err = nft_data_init(NULL, &data, sizeof(data), &desc,
d0a11fc3 PM	162	tb[NFTA_CMP_DATA]);
fa5950e4 FW	163	if (err < 0)
fa5950e4 FW	164	return err;
cb7dbfd0	165
b1c96ed3	166	priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
d07db988 PM	167	err = nft_validate_register_load(priv->sreg, desc.len);
	168	if (err < 0)
	169	return err;
	170
	171	desc.len *= BITS_PER_BYTE;
b855d416	172	mask = nft_cmp_fast_mask(desc.len);
d07db988	173
cb7dbfd0 PM	174	priv->data = data.data[0] & mask;
	175	priv->len = desc.len;
	176	return 0;
	177	}
	178
c9626a2c PNA	179	static int nft_cmp_fast_offload(struct nft_offload_ctx *ctx,
	180	struct nft_flow_rule *flow,
	181	const struct nft_expr *expr)
	182	{
	183	const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	184	struct nft_cmp_expr cmp = {
	185	.data = {
	186	.data = {
	187	[0] = priv->data,
	188	},
	189	},
	190	.sreg = priv->sreg,
	191	.len = priv->len / BITS_PER_BYTE,
	192	.op = NFT_CMP_EQ,
	193	};
	194
	195	return __nft_cmp_offload(ctx, flow, &cmp);
	196	}
	197
cb7dbfd0 PM	198	static int nft_cmp_fast_dump(struct sk_buff skb, const struct nft_expr expr)
	199	{
	200	const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	201	struct nft_data data;
	202
b1c96ed3	203	if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
cb7dbfd0 PM	204	goto nla_put_failure;
	205	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(NFT_CMP_EQ)))
	206	goto nla_put_failure;
	207
	208	data.data[0] = priv->data;
	209	if (nft_data_dump(skb, NFTA_CMP_DATA, &data,
	210	NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0)
	211	goto nla_put_failure;
	212	return 0;
	213
	214	nla_put_failure:
	215	return -1;
	216	}
	217
	218	const struct nft_expr_ops nft_cmp_fast_ops = {
	219	.type = &nft_cmp_type,
	220	.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),
	221	.eval = NULL, /* inlined */
	222	.init = nft_cmp_fast_init,
	223	.dump = nft_cmp_fast_dump,
c9626a2c	224	.offload = nft_cmp_fast_offload,
cb7dbfd0 PM	225	};
cb7dbfd0 PM	226
0ca743a5 PNA	227	static const struct nft_expr_ops *
0ca743a5 PNA	228	nft_cmp_select_ops(const struct nft_ctx ctx, const struct nlattr const tb[])
cb7dbfd0 PM	229	{
	230	struct nft_data_desc desc;
	231	struct nft_data data;
cb7dbfd0 PM	232	enum nft_cmp_ops op;
	233	int err;
	234
	235	if (tb[NFTA_CMP_SREG] == NULL \|\|
	236	tb[NFTA_CMP_OP] == NULL \|\|
	237	tb[NFTA_CMP_DATA] == NULL)
	238	return ERR_PTR(-EINVAL);
	239
cb7dbfd0 PM	240	op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
	241	switch (op) {
	242	case NFT_CMP_EQ:
	243	case NFT_CMP_NEQ:
	244	case NFT_CMP_LT:
	245	case NFT_CMP_LTE:
	246	case NFT_CMP_GT:
	247	case NFT_CMP_GTE:
	248	break;
	249	default:
	250	return ERR_PTR(-EINVAL);
	251	}
	252
d0a11fc3 PM	253	err = nft_data_init(NULL, &data, sizeof(data), &desc,
d0a11fc3 PM	254	tb[NFTA_CMP_DATA]);
cb7dbfd0 PM	255	if (err < 0)
	256	return ERR_PTR(err);
	257
71df14b0 PNA	258	if (desc.type != NFT_DATA_VALUE) {
	259	err = -EINVAL;
	260	goto err1;
	261	}
	262
cb7dbfd0 PM	263	if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ)
cb7dbfd0 PM	264	return &nft_cmp_fast_ops;
71df14b0 PNA	265
	266	return &nft_cmp_ops;
	267	err1:
59105446	268	nft_data_release(&data, desc.type);
71df14b0	269	return ERR_PTR(-EINVAL);
cb7dbfd0 PM	270	}
cb7dbfd0 PM	271
4e24877e	272	struct nft_expr_type nft_cmp_type __read_mostly = {
ef1f7df9	273	.name = "cmp",
cb7dbfd0	274	.select_ops = nft_cmp_select_ops,
96518518 PM	275	.policy = nft_cmp_policy,
96518518 PM	276	.maxattr = NFTA_CMP_MAX,
ef1f7df9	277	.owner = THIS_MODULE,
96518518	278	};