[linux-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/if_arp.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 || reg->len != priv->len)
		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;

	if (reg->key == FLOW_DISSECTOR_KEY_META &&
	    reg->offset == offsetof(struct nft_flow_key, meta.ingress_iftype) &&
	    nft_reg_load16(priv->data.data) != ARPHRD_ETHER)
		return -EOPNOTSUPP;

	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>
8819efc9	13	#include <linux/if_arp.h>
96518518 PM	14	#include <linux/netfilter/nf_tables.h>
96518518 PM	15	#include <net/netfilter/nf_tables_core.h>
c9626a2c	16	#include <net/netfilter/nf_tables_offload.h>
96518518 PM	17	#include <net/netfilter/nf_tables.h>
	18
	19	struct nft_cmp_expr {
	20	struct nft_data data;
	21	enum nft_registers sreg:8;
	22	u8 len;
	23	enum nft_cmp_ops op:8;
	24	};
	25
10870dd8 FW	26	void nft_cmp_eval(const struct nft_expr *expr,
	27	struct nft_regs *regs,
	28	const struct nft_pktinfo *pkt)
96518518 PM	29	{
	30	const struct nft_cmp_expr *priv = nft_expr_priv(expr);
	31	int d;
	32
e562d860	33	d = memcmp(&regs->data[priv->sreg], &priv->data, priv->len);
96518518 PM	34	switch (priv->op) {
	35	case NFT_CMP_EQ:
	36	if (d != 0)
	37	goto mismatch;
	38	break;
	39	case NFT_CMP_NEQ:
	40	if (d == 0)
	41	goto mismatch;
	42	break;
	43	case NFT_CMP_LT:
	44	if (d == 0)
	45	goto mismatch;
e8542dce	46	/* fall through */
96518518 PM	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;
e8542dce	54	/* fall through */
96518518 PM	55	case NFT_CMP_GTE:
	56	if (d < 0)
	57	goto mismatch;
	58	break;
	59	}
	60	return;
	61
	62	mismatch:
a55e22e9	63	regs->verdict.code = NFT_BREAK;
96518518 PM	64	}
	65
	66	static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = {
	67	[NFTA_CMP_SREG] = { .type = NLA_U32 },
	68	[NFTA_CMP_OP] = { .type = NLA_U32 },
	69	[NFTA_CMP_DATA] = { .type = NLA_NESTED },
	70	};
	71
	72	static int nft_cmp_init(const struct nft_ctx ctx, const struct nft_expr expr,
	73	const struct nlattr * const tb[])
	74	{
	75	struct nft_cmp_expr *priv = nft_expr_priv(expr);
	76	struct nft_data_desc desc;
	77	int err;
	78
d0a11fc3 PM	79	err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc,
d0a11fc3 PM	80	tb[NFTA_CMP_DATA]);
fa5950e4 FW	81	if (err < 0)
fa5950e4 FW	82	return err;
96518518	83
b1c96ed3	84	priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
d07db988 PM	85	err = nft_validate_register_load(priv->sreg, desc.len);
	86	if (err < 0)
	87	return err;
	88
	89	priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
96518518 PM	90	priv->len = desc.len;
	91	return 0;
	92	}
	93
	94	static int nft_cmp_dump(struct sk_buff skb, const struct nft_expr expr)
	95	{
	96	const struct nft_cmp_expr *priv = nft_expr_priv(expr);
	97
b1c96ed3	98	if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
96518518 PM	99	goto nla_put_failure;
	100	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))
	101	goto nla_put_failure;
	102
	103	if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
	104	NFT_DATA_VALUE, priv->len) < 0)
	105	goto nla_put_failure;
	106	return 0;
	107
	108	nla_put_failure:
	109	return -1;
	110	}
	111
c9626a2c PNA	112	static int __nft_cmp_offload(struct nft_offload_ctx *ctx,
	113	struct nft_flow_rule *flow,
	114	const struct nft_cmp_expr *priv)
	115	{
	116	struct nft_offload_reg *reg = &ctx->regs[priv->sreg];
	117	u8 mask = (u8 )&flow->match.mask;
	118	u8 key = (u8 )&flow->match.key;
	119
de2a6052	120	if (priv->op != NFT_CMP_EQ \|\| reg->len != priv->len)
c9626a2c PNA	121	return -EOPNOTSUPP;
	122
	123	memcpy(key + reg->offset, &priv->data, priv->len);
	124	memcpy(mask + reg->offset, &reg->mask, priv->len);
	125
	126	flow->match.dissector.used_keys \|= BIT(reg->key);
	127	flow->match.dissector.offset[reg->key] = reg->base_offset;
	128
8819efc9 PNA	129	if (reg->key == FLOW_DISSECTOR_KEY_META &&
	130	reg->offset == offsetof(struct nft_flow_key, meta.ingress_iftype) &&
	131	nft_reg_load16(priv->data.data) != ARPHRD_ETHER)
	132	return -EOPNOTSUPP;
	133
c9626a2c PNA	134	nft_offload_update_dependency(ctx, &priv->data, priv->len);
	135
	136	return 0;
	137	}
	138
	139	static int nft_cmp_offload(struct nft_offload_ctx *ctx,
	140	struct nft_flow_rule *flow,
	141	const struct nft_expr *expr)
	142	{
	143	const struct nft_cmp_expr *priv = nft_expr_priv(expr);
	144
	145	return __nft_cmp_offload(ctx, flow, priv);
	146	}
	147
ef1f7df9 PM	148	static const struct nft_expr_ops nft_cmp_ops = {
ef1f7df9 PM	149	.type = &nft_cmp_type,
96518518	150	.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),
96518518 PM	151	.eval = nft_cmp_eval,
	152	.init = nft_cmp_init,
	153	.dump = nft_cmp_dump,
c9626a2c	154	.offload = nft_cmp_offload,
ef1f7df9 PM	155	};
ef1f7df9 PM	156
cb7dbfd0 PM	157	static int nft_cmp_fast_init(const struct nft_ctx *ctx,
	158	const struct nft_expr *expr,
	159	const struct nlattr * const tb[])
	160	{
	161	struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	162	struct nft_data_desc desc;
	163	struct nft_data data;
	164	u32 mask;
	165	int err;
	166
d0a11fc3 PM	167	err = nft_data_init(NULL, &data, sizeof(data), &desc,
d0a11fc3 PM	168	tb[NFTA_CMP_DATA]);
fa5950e4 FW	169	if (err < 0)
fa5950e4 FW	170	return err;
cb7dbfd0	171
b1c96ed3	172	priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
d07db988 PM	173	err = nft_validate_register_load(priv->sreg, desc.len);
	174	if (err < 0)
	175	return err;
	176
	177	desc.len *= BITS_PER_BYTE;
b855d416	178	mask = nft_cmp_fast_mask(desc.len);
d07db988	179
cb7dbfd0 PM	180	priv->data = data.data[0] & mask;
	181	priv->len = desc.len;
	182	return 0;
	183	}
	184
c9626a2c PNA	185	static int nft_cmp_fast_offload(struct nft_offload_ctx *ctx,
	186	struct nft_flow_rule *flow,
	187	const struct nft_expr *expr)
	188	{
	189	const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	190	struct nft_cmp_expr cmp = {
	191	.data = {
	192	.data = {
	193	[0] = priv->data,
	194	},
	195	},
	196	.sreg = priv->sreg,
	197	.len = priv->len / BITS_PER_BYTE,
	198	.op = NFT_CMP_EQ,
	199	};
	200
	201	return __nft_cmp_offload(ctx, flow, &cmp);
	202	}
	203
cb7dbfd0 PM	204	static int nft_cmp_fast_dump(struct sk_buff skb, const struct nft_expr expr)
	205	{
	206	const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
	207	struct nft_data data;
	208
b1c96ed3	209	if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
cb7dbfd0 PM	210	goto nla_put_failure;
	211	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(NFT_CMP_EQ)))
	212	goto nla_put_failure;
	213
	214	data.data[0] = priv->data;
	215	if (nft_data_dump(skb, NFTA_CMP_DATA, &data,
	216	NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0)
	217	goto nla_put_failure;
	218	return 0;
	219
	220	nla_put_failure:
	221	return -1;
	222	}
	223
	224	const struct nft_expr_ops nft_cmp_fast_ops = {
	225	.type = &nft_cmp_type,
	226	.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),
	227	.eval = NULL, /* inlined */
	228	.init = nft_cmp_fast_init,
	229	.dump = nft_cmp_fast_dump,
c9626a2c	230	.offload = nft_cmp_fast_offload,
cb7dbfd0 PM	231	};
cb7dbfd0 PM	232
0ca743a5 PNA	233	static const struct nft_expr_ops *
0ca743a5 PNA	234	nft_cmp_select_ops(const struct nft_ctx ctx, const struct nlattr const tb[])
cb7dbfd0 PM	235	{
	236	struct nft_data_desc desc;
	237	struct nft_data data;
cb7dbfd0 PM	238	enum nft_cmp_ops op;
	239	int err;
	240
	241	if (tb[NFTA_CMP_SREG] == NULL \|\|
	242	tb[NFTA_CMP_OP] == NULL \|\|
	243	tb[NFTA_CMP_DATA] == NULL)
	244	return ERR_PTR(-EINVAL);
	245
cb7dbfd0 PM	246	op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
	247	switch (op) {
	248	case NFT_CMP_EQ:
	249	case NFT_CMP_NEQ:
	250	case NFT_CMP_LT:
	251	case NFT_CMP_LTE:
	252	case NFT_CMP_GT:
	253	case NFT_CMP_GTE:
	254	break;
	255	default:
	256	return ERR_PTR(-EINVAL);
	257	}
	258
d0a11fc3 PM	259	err = nft_data_init(NULL, &data, sizeof(data), &desc,
d0a11fc3 PM	260	tb[NFTA_CMP_DATA]);
cb7dbfd0 PM	261	if (err < 0)
	262	return ERR_PTR(err);
	263
71df14b0 PNA	264	if (desc.type != NFT_DATA_VALUE) {
	265	err = -EINVAL;
	266	goto err1;
	267	}
	268
cb7dbfd0 PM	269	if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ)
cb7dbfd0 PM	270	return &nft_cmp_fast_ops;
71df14b0 PNA	271
	272	return &nft_cmp_ops;
	273	err1:
59105446	274	nft_data_release(&data, desc.type);
71df14b0	275	return ERR_PTR(-EINVAL);
cb7dbfd0 PM	276	}
cb7dbfd0 PM	277
4e24877e	278	struct nft_expr_type nft_cmp_type __read_mostly = {
ef1f7df9	279	.name = "cmp",
cb7dbfd0	280	.select_ops = nft_cmp_select_ops,
96518518 PM	281	.policy = nft_cmp_policy,
96518518 PM	282	.maxattr = NFTA_CMP_MAX,
ef1f7df9	283	.owner = THIS_MODULE,
96518518	284	};