[deliverable/linux.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;
};

static void nft_exthdr_eval(const struct nft_expr *expr,
			    struct nft_data data[NFT_REG_MAX + 1],
			    const struct nft_pktinfo *pkt)
{
	struct nft_exthdr *priv = nft_expr_priv(expr);
	struct nft_data *dest = &data[priv->dreg];
	unsigned int offset = 0;
	int err;

	err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL);
	if (err < 0)
		goto err;
	offset += priv->offset;

	if (skb_copy_bits(pkt->skb, offset, dest->data, priv->len) < 0)
		goto err;
	return;
err:
	data[NFT_REG_VERDICT].verdict = 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 },
};

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);
	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;

	priv->type   = nla_get_u8(tb[NFTA_EXTHDR_TYPE]);
	priv->offset = ntohl(nla_get_be32(tb[NFTA_EXTHDR_OFFSET]));
	priv->len    = ntohl(nla_get_be32(tb[NFTA_EXTHDR_LEN]));
	if (priv->len == 0 ||
	    priv->len > FIELD_SIZEOF(struct nft_data, data))
		return -EINVAL;

	priv->dreg = ntohl(nla_get_be32(tb[NFTA_EXTHDR_DREG]));
	err = nft_validate_output_register(priv->dreg);
	if (err < 0)
		return err;
	return nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE);
}

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

	if (nla_put_be32(skb, NFTA_EXTHDR_DREG, htonl(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;
	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;
	26	};
	27
	28	static void nft_exthdr_eval(const struct nft_expr *expr,
	29	struct nft_data data[NFT_REG_MAX + 1],
	30	const struct nft_pktinfo *pkt)
	31	{
	32	struct nft_exthdr *priv = nft_expr_priv(expr);
	33	struct nft_data *dest = &data[priv->dreg];
540436c8	34	unsigned int offset = 0;
96518518 PM	35	int err;
	36
	37	err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL);
	38	if (err < 0)
	39	goto err;
	40	offset += priv->offset;
	41
	42	if (skb_copy_bits(pkt->skb, offset, dest->data, priv->len) < 0)
	43	goto err;
	44	return;
	45	err:
	46	data[NFT_REG_VERDICT].verdict = NFT_BREAK;
	47	}
	48
	49	static const struct nla_policy nft_exthdr_policy[NFTA_EXTHDR_MAX + 1] = {
	50	[NFTA_EXTHDR_DREG] = { .type = NLA_U32 },
	51	[NFTA_EXTHDR_TYPE] = { .type = NLA_U8 },
	52	[NFTA_EXTHDR_OFFSET] = { .type = NLA_U32 },
	53	[NFTA_EXTHDR_LEN] = { .type = NLA_U32 },
	54	};
	55
	56	static int nft_exthdr_init(const struct nft_ctx *ctx,
	57	const struct nft_expr *expr,
	58	const struct nlattr * const tb[])
	59	{
	60	struct nft_exthdr *priv = nft_expr_priv(expr);
	61	int err;
	62
	63	if (tb[NFTA_EXTHDR_DREG] == NULL \|\|
	64	tb[NFTA_EXTHDR_TYPE] == NULL \|\|
	65	tb[NFTA_EXTHDR_OFFSET] == NULL \|\|
	66	tb[NFTA_EXTHDR_LEN] == NULL)
	67	return -EINVAL;
	68
	69	priv->type = nla_get_u8(tb[NFTA_EXTHDR_TYPE]);
	70	priv->offset = ntohl(nla_get_be32(tb[NFTA_EXTHDR_OFFSET]));
	71	priv->len = ntohl(nla_get_be32(tb[NFTA_EXTHDR_LEN]));
	72	if (priv->len == 0 \|\|
	73	priv->len > FIELD_SIZEOF(struct nft_data, data))
	74	return -EINVAL;
	75
	76	priv->dreg = ntohl(nla_get_be32(tb[NFTA_EXTHDR_DREG]));
	77	err = nft_validate_output_register(priv->dreg);
	78	if (err < 0)
	79	return err;
	80	return nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE);
	81	}
	82
	83	static int nft_exthdr_dump(struct sk_buff skb, const struct nft_expr expr)
	84	{
	85	const struct nft_exthdr *priv = nft_expr_priv(expr);
	86
	87	if (nla_put_be32(skb, NFTA_EXTHDR_DREG, htonl(priv->dreg)))
	88	goto nla_put_failure;
	89	if (nla_put_u8(skb, NFTA_EXTHDR_TYPE, priv->type))
	90	goto nla_put_failure;
	91	if (nla_put_be32(skb, NFTA_EXTHDR_OFFSET, htonl(priv->offset)))
	92	goto nla_put_failure;
	93	if (nla_put_be32(skb, NFTA_EXTHDR_LEN, htonl(priv->len)))
	94	goto nla_put_failure;
	95	return 0;
	96
	97	nla_put_failure:
	98	return -1;
99	}
100
ef1f7df9 PM	101	static struct nft_expr_type nft_exthdr_type;
	102	static const struct nft_expr_ops nft_exthdr_ops = {
	103	.type = &nft_exthdr_type,
96518518	104	.size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
96518518 PM	105	.eval = nft_exthdr_eval,
	106	.init = nft_exthdr_init,
	107	.dump = nft_exthdr_dump,
ef1f7df9 PM	108	};
	109
	110	static struct nft_expr_type nft_exthdr_type __read_mostly = {
	111	.name = "exthdr",
	112	.ops = &nft_exthdr_ops,
96518518 PM	113	.policy = nft_exthdr_policy,
96518518 PM	114	.maxattr = NFTA_EXTHDR_MAX,
ef1f7df9	115	.owner = THIS_MODULE,
96518518 PM	116	};
	117
	118	static int __init nft_exthdr_module_init(void)
	119	{
ef1f7df9	120	return nft_register_expr(&nft_exthdr_type);
96518518 PM	121	}
	122
	123	static void __exit nft_exthdr_module_exit(void)
	124	{
ef1f7df9	125	nft_unregister_expr(&nft_exthdr_type);
96518518 PM	126	}
	127
	128	module_init(nft_exthdr_module_init);
	129	module_exit(nft_exthdr_module_exit);
	130
	131	MODULE_LICENSE("GPL");
	132	MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
	133	MODULE_ALIAS_NFT_EXPR("exthdr");