[mirror_ubuntu-bionic-kernel.git] / net / netfilter / nft_exthdr.c

/*
 * Copyright (c) 2008 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.h>
// FIXME:
#include <net/ipv6.h>

struct nft_exthdr {
	u8			type;
	u8			offset;
	u8			len;
	enum nft_registers	dreg:8;
	u8			flags;
};

static void nft_exthdr_eval(const struct nft_expr *expr,
			    struct nft_regs *regs,
			    const struct nft_pktinfo *pkt)
{
	struct nft_exthdr *priv = nft_expr_priv(expr);
	u32 *dest = &regs->data[priv->dreg];
	unsigned int offset = 0;
	int err;

	err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL);
	if (priv->flags & NFT_EXTHDR_F_PRESENT) {
		*dest = (err >= 0);
		return;
	} else if (err < 0) {
		goto err;
	}
	offset += priv->offset;

	dest[priv->len / NFT_REG32_SIZE] = 0;
	if (skb_copy_bits(pkt->skb, offset, dest, priv->len) < 0)
		goto err;
	return;
err:
	regs->verdict.code = NFT_BREAK;
}

static const struct nla_policy nft_exthdr_policy[NFTA_EXTHDR_MAX + 1] = {
	[NFTA_EXTHDR_DREG]		= { .type = NLA_U32 },
	[NFTA_EXTHDR_TYPE]		= { .type = NLA_U8 },
	[NFTA_EXTHDR_OFFSET]		= { .type = NLA_U32 },
	[NFTA_EXTHDR_LEN]		= { .type = NLA_U32 },
	[NFTA_EXTHDR_FLAGS]		= { .type = NLA_U32 },
};

static int nft_exthdr_init(const struct nft_ctx *ctx,
			   const struct nft_expr *expr,
			   const struct nlattr * const tb[])
{
	struct nft_exthdr *priv = nft_expr_priv(expr);
	u32 offset, len, flags = 0;
	int err;

	if (tb[NFTA_EXTHDR_DREG] == NULL ||
	    tb[NFTA_EXTHDR_TYPE] == NULL ||
	    tb[NFTA_EXTHDR_OFFSET] == NULL ||
	    tb[NFTA_EXTHDR_LEN] == NULL)
		return -EINVAL;

	err = nft_parse_u32_check(tb[NFTA_EXTHDR_OFFSET], U8_MAX, &offset);
	if (err < 0)
		return err;

	err = nft_parse_u32_check(tb[NFTA_EXTHDR_LEN], U8_MAX, &len);
	if (err < 0)
		return err;

	if (tb[NFTA_EXTHDR_FLAGS]) {
		err = nft_parse_u32_check(tb[NFTA_EXTHDR_FLAGS], U8_MAX, &flags);
		if (err < 0)
			return err;

		if (flags & ~NFT_EXTHDR_F_PRESENT)
			return -EINVAL;
	}

	priv->type   = nla_get_u8(tb[NFTA_EXTHDR_TYPE]);
	priv->offset = offset;
	priv->len    = len;
	priv->dreg   = nft_parse_register(tb[NFTA_EXTHDR_DREG]);
	priv->flags  = flags;

	return nft_validate_register_store(ctx, priv->dreg, NULL,
					   NFT_DATA_VALUE, priv->len);
}

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

	if (nft_dump_register(skb, NFTA_EXTHDR_DREG, priv->dreg))
		goto nla_put_failure;
	if (nla_put_u8(skb, NFTA_EXTHDR_TYPE, priv->type))
		goto nla_put_failure;
	if (nla_put_be32(skb, NFTA_EXTHDR_OFFSET, htonl(priv->offset)))
		goto nla_put_failure;
	if (nla_put_be32(skb, NFTA_EXTHDR_LEN, htonl(priv->len)))
		goto nla_put_failure;
	if (nla_put_be32(skb, NFTA_EXTHDR_FLAGS, htonl(priv->flags)))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -1;
}

static struct nft_expr_type nft_exthdr_type;
static const struct nft_expr_ops nft_exthdr_ops = {
	.type		= &nft_exthdr_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
	.eval		= nft_exthdr_eval,
	.init		= nft_exthdr_init,
	.dump		= nft_exthdr_dump,
};

static struct nft_expr_type nft_exthdr_type __read_mostly = {
	.name		= "exthdr",
	.ops		= &nft_exthdr_ops,
	.policy		= nft_exthdr_policy,
	.maxattr	= NFTA_EXTHDR_MAX,
	.owner		= THIS_MODULE,
};

static int __init nft_exthdr_module_init(void)
{
	return nft_register_expr(&nft_exthdr_type);
}

static void __exit nft_exthdr_module_exit(void)
{
	nft_unregister_expr(&nft_exthdr_type);
}

module_init(nft_exthdr_module_init);
module_exit(nft_exthdr_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_ALIAS_NFT_EXPR("exthdr");
Commit	Line	Data
96518518 PM	1	/*
	2	* Copyright (c) 2008 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	* 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.h>
	18	// FIXME:
	19	#include <net/ipv6.h>
	20
	21	struct nft_exthdr {
	22	u8 type;
	23	u8 offset;
	24	u8 len;
	25	enum nft_registers dreg:8;
c078ca3b	26	u8 flags;
96518518 PM	27	};
	28
	29	static void nft_exthdr_eval(const struct nft_expr *expr,
a55e22e9	30	struct nft_regs *regs,
96518518 PM	31	const struct nft_pktinfo *pkt)
	32	{
	33	struct nft_exthdr *priv = nft_expr_priv(expr);
49499c3e	34	u32 *dest = &regs->data[priv->dreg];
540436c8	35	unsigned int offset = 0;
96518518 PM	36	int err;
	37
	38	err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL);
c078ca3b PS	39	if (priv->flags & NFT_EXTHDR_F_PRESENT) {
	40	*dest = (err >= 0);
	41	return;
	42	} else if (err < 0) {
96518518	43	goto err;
c078ca3b	44	}
96518518 PM	45	offset += priv->offset;
96518518 PM	46
49499c3e	47	dest[priv->len / NFT_REG32_SIZE] = 0;
fad136ea	48	if (skb_copy_bits(pkt->skb, offset, dest, priv->len) < 0)
96518518 PM	49	goto err;
	50	return;
	51	err:
a55e22e9	52	regs->verdict.code = NFT_BREAK;
96518518 PM	53	}
	54
	55	static const struct nla_policy nft_exthdr_policy[NFTA_EXTHDR_MAX + 1] = {
	56	[NFTA_EXTHDR_DREG] = { .type = NLA_U32 },
	57	[NFTA_EXTHDR_TYPE] = { .type = NLA_U8 },
	58	[NFTA_EXTHDR_OFFSET] = { .type = NLA_U32 },
	59	[NFTA_EXTHDR_LEN] = { .type = NLA_U32 },
c078ca3b	60	[NFTA_EXTHDR_FLAGS] = { .type = NLA_U32 },
96518518 PM	61	};
	62
	63	static int nft_exthdr_init(const struct nft_ctx *ctx,
	64	const struct nft_expr *expr,
	65	const struct nlattr * const tb[])
	66	{
	67	struct nft_exthdr *priv = nft_expr_priv(expr);
c078ca3b	68	u32 offset, len, flags = 0;
21a9e0f1	69	int err;
96518518 PM	70
	71	if (tb[NFTA_EXTHDR_DREG] == NULL \|\|
	72	tb[NFTA_EXTHDR_TYPE] == NULL \|\|
	73	tb[NFTA_EXTHDR_OFFSET] == NULL \|\|
	74	tb[NFTA_EXTHDR_LEN] == NULL)
	75	return -EINVAL;
	76
36b701fa LGL	77	err = nft_parse_u32_check(tb[NFTA_EXTHDR_OFFSET], U8_MAX, &offset);
	78	if (err < 0)
	79	return err;
4da449ae	80
36b701fa LGL	81	err = nft_parse_u32_check(tb[NFTA_EXTHDR_LEN], U8_MAX, &len);
	82	if (err < 0)
	83	return err;
4da449ae	84
c078ca3b PS	85	if (tb[NFTA_EXTHDR_FLAGS]) {
	86	err = nft_parse_u32_check(tb[NFTA_EXTHDR_FLAGS], U8_MAX, &flags);
	87	if (err < 0)
	88	return err;
	89
	90	if (flags & ~NFT_EXTHDR_F_PRESENT)
	91	return -EINVAL;
	92	}
	93
96518518	94	priv->type = nla_get_u8(tb[NFTA_EXTHDR_TYPE]);
4da449ae LGL	95	priv->offset = offset;
4da449ae LGL	96	priv->len = len;
b1c96ed3	97	priv->dreg = nft_parse_register(tb[NFTA_EXTHDR_DREG]);
c078ca3b	98	priv->flags = flags;
96518518	99
1ec10212 PM	100	return nft_validate_register_store(ctx, priv->dreg, NULL,
1ec10212 PM	101	NFT_DATA_VALUE, priv->len);
96518518 PM	102	}
	103
	104	static int nft_exthdr_dump(struct sk_buff skb, const struct nft_expr expr)
	105	{
	106	const struct nft_exthdr *priv = nft_expr_priv(expr);
	107
b1c96ed3	108	if (nft_dump_register(skb, NFTA_EXTHDR_DREG, priv->dreg))
96518518 PM	109	goto nla_put_failure;
	110	if (nla_put_u8(skb, NFTA_EXTHDR_TYPE, priv->type))
	111	goto nla_put_failure;
	112	if (nla_put_be32(skb, NFTA_EXTHDR_OFFSET, htonl(priv->offset)))
	113	goto nla_put_failure;
	114	if (nla_put_be32(skb, NFTA_EXTHDR_LEN, htonl(priv->len)))
	115	goto nla_put_failure;
c078ca3b PS	116	if (nla_put_be32(skb, NFTA_EXTHDR_FLAGS, htonl(priv->flags)))
c078ca3b PS	117	goto nla_put_failure;
96518518 PM	118	return 0;
	119
	120	nla_put_failure:
	121	return -1;
	122	}
	123
ef1f7df9 PM	124	static struct nft_expr_type nft_exthdr_type;
	125	static const struct nft_expr_ops nft_exthdr_ops = {
	126	.type = &nft_exthdr_type,
96518518	127	.size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
96518518 PM	128	.eval = nft_exthdr_eval,
	129	.init = nft_exthdr_init,
	130	.dump = nft_exthdr_dump,
ef1f7df9 PM	131	};
	132
	133	static struct nft_expr_type nft_exthdr_type __read_mostly = {
	134	.name = "exthdr",
	135	.ops = &nft_exthdr_ops,
96518518 PM	136	.policy = nft_exthdr_policy,
96518518 PM	137	.maxattr = NFTA_EXTHDR_MAX,
ef1f7df9	138	.owner = THIS_MODULE,
96518518 PM	139	};
	140
	141	static int __init nft_exthdr_module_init(void)
	142	{
ef1f7df9	143	return nft_register_expr(&nft_exthdr_type);
96518518 PM	144	}
	145
	146	static void __exit nft_exthdr_module_exit(void)
	147	{
ef1f7df9	148	nft_unregister_expr(&nft_exthdr_type);
96518518 PM	149	}
	150
	151	module_init(nft_exthdr_module_init);
	152	module_exit(nft_exthdr_module_exit);
	153
	154	MODULE_LICENSE("GPL");
	155	MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
	156	MODULE_ALIAS_NFT_EXPR("exthdr");