[mirror_ubuntu-bionic-kernel.git] / net / netfilter / nft_payload.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/if_vlan.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>

/* add vlan header into the user buffer for if tag was removed by offloads */
static bool
nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len)
{
	int mac_off = skb_mac_header(skb) - skb->data;
	u8 vlan_len, *vlanh, *dst_u8 = (u8 *) d;
	struct vlan_ethhdr veth;

	vlanh = (u8 *) &veth;
	if (offset < ETH_HLEN) {
		u8 ethlen = min_t(u8, len, ETH_HLEN - offset);

		if (skb_copy_bits(skb, mac_off, &veth, ETH_HLEN))
			return false;

		veth.h_vlan_proto = skb->vlan_proto;

		memcpy(dst_u8, vlanh + offset, ethlen);

		len -= ethlen;
		if (len == 0)
			return true;

		dst_u8 += ethlen;
		offset = ETH_HLEN;
	} else if (offset >= VLAN_ETH_HLEN) {
		offset -= VLAN_HLEN;
		goto skip;
	}

	veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
	veth.h_vlan_encapsulated_proto = skb->protocol;

	vlanh += offset;

	vlan_len = min_t(u8, len, VLAN_ETH_HLEN - offset);
	memcpy(dst_u8, vlanh, vlan_len);

	len -= vlan_len;
	if (!len)
		return true;

	dst_u8 += vlan_len;
 skip:
	return skb_copy_bits(skb, offset + mac_off, dst_u8, len) == 0;
}

static void nft_payload_eval(const struct nft_expr *expr,
			     struct nft_regs *regs,
			     const struct nft_pktinfo *pkt)
{
	const struct nft_payload *priv = nft_expr_priv(expr);
	const struct sk_buff *skb = pkt->skb;
	u32 *dest = &regs->data[priv->dreg];
	int offset;

	dest[priv->len / NFT_REG32_SIZE] = 0;
	switch (priv->base) {
	case NFT_PAYLOAD_LL_HEADER:
		if (!skb_mac_header_was_set(skb))
			goto err;

		if (skb_vlan_tag_present(skb)) {
			if (!nft_payload_copy_vlan(dest, skb,
						   priv->offset, priv->len))
				goto err;
			return;
		}
		offset = skb_mac_header(skb) - skb->data;
		break;
	case NFT_PAYLOAD_NETWORK_HEADER:
		offset = skb_network_offset(skb);
		break;
	case NFT_PAYLOAD_TRANSPORT_HEADER:
		offset = pkt->xt.thoff;
		break;
	default:
		BUG();
	}
	offset += priv->offset;

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

static const struct nla_policy nft_payload_policy[NFTA_PAYLOAD_MAX + 1] = {
	[NFTA_PAYLOAD_DREG]	= { .type = NLA_U32 },
	[NFTA_PAYLOAD_BASE]	= { .type = NLA_U32 },
	[NFTA_PAYLOAD_OFFSET]	= { .type = NLA_U32 },
	[NFTA_PAYLOAD_LEN]	= { .type = NLA_U32 },
};

static int nft_payload_init(const struct nft_ctx *ctx,
			    const struct nft_expr *expr,
			    const struct nlattr * const tb[])
{
	struct nft_payload *priv = nft_expr_priv(expr);

	priv->base   = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
	priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
	priv->len    = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
	priv->dreg   = nft_parse_register(tb[NFTA_PAYLOAD_DREG]);

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

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

	if (nft_dump_register(skb, NFTA_PAYLOAD_DREG, priv->dreg) ||
	    nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) ||
	    nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) ||
	    nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len)))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -1;
}

static struct nft_expr_type nft_payload_type;
static const struct nft_expr_ops nft_payload_ops = {
	.type		= &nft_payload_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_payload)),
	.eval		= nft_payload_eval,
	.init		= nft_payload_init,
	.dump		= nft_payload_dump,
};

const struct nft_expr_ops nft_payload_fast_ops = {
	.type		= &nft_payload_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_payload)),
	.eval		= nft_payload_eval,
	.init		= nft_payload_init,
	.dump		= nft_payload_dump,
};

static const struct nft_expr_ops *
nft_payload_select_ops(const struct nft_ctx *ctx,
		       const struct nlattr * const tb[])
{
	enum nft_payload_bases base;
	unsigned int offset, len;

	if (tb[NFTA_PAYLOAD_DREG] == NULL ||
	    tb[NFTA_PAYLOAD_BASE] == NULL ||
	    tb[NFTA_PAYLOAD_OFFSET] == NULL ||
	    tb[NFTA_PAYLOAD_LEN] == NULL)
		return ERR_PTR(-EINVAL);

	base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
	switch (base) {
	case NFT_PAYLOAD_LL_HEADER:
	case NFT_PAYLOAD_NETWORK_HEADER:
	case NFT_PAYLOAD_TRANSPORT_HEADER:
		break;
	default:
		return ERR_PTR(-EOPNOTSUPP);
	}

	offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
	len    = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));

	if (len <= 4 && is_power_of_2(len) && IS_ALIGNED(offset, len) &&
	    base != NFT_PAYLOAD_LL_HEADER)
		return &nft_payload_fast_ops;
	else
		return &nft_payload_ops;
}

static struct nft_expr_type nft_payload_type __read_mostly = {
	.name		= "payload",
	.select_ops	= nft_payload_select_ops,
	.policy		= nft_payload_policy,
	.maxattr	= NFTA_PAYLOAD_MAX,
	.owner		= THIS_MODULE,
};

int __init nft_payload_module_init(void)
{
	return nft_register_expr(&nft_payload_type);
}

void nft_payload_module_exit(void)
{
	nft_unregister_expr(&nft_payload_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>
8cfd23e6	12	#include <linux/if_vlan.h>
96518518 PM	13	#include <linux/init.h>
	14	#include <linux/module.h>
	15	#include <linux/netlink.h>
	16	#include <linux/netfilter.h>
	17	#include <linux/netfilter/nf_tables.h>
	18	#include <net/netfilter/nf_tables_core.h>
	19	#include <net/netfilter/nf_tables.h>
	20
8cfd23e6 FW	21	/* add vlan header into the user buffer for if tag was removed by offloads */
	22	static bool
	23	nft_payload_copy_vlan(u32 d, const struct sk_buff skb, u8 offset, u8 len)
	24	{
	25	int mac_off = skb_mac_header(skb) - skb->data;
	26	u8 vlan_len, vlanh, dst_u8 = (u8 *) d;
	27	struct vlan_ethhdr veth;
	28
	29	vlanh = (u8 *) &veth;
	30	if (offset < ETH_HLEN) {
	31	u8 ethlen = min_t(u8, len, ETH_HLEN - offset);
	32
	33	if (skb_copy_bits(skb, mac_off, &veth, ETH_HLEN))
	34	return false;
	35
	36	veth.h_vlan_proto = skb->vlan_proto;
	37
	38	memcpy(dst_u8, vlanh + offset, ethlen);
	39
	40	len -= ethlen;
	41	if (len == 0)
	42	return true;
	43
	44	dst_u8 += ethlen;
	45	offset = ETH_HLEN;
	46	} else if (offset >= VLAN_ETH_HLEN) {
	47	offset -= VLAN_HLEN;
	48	goto skip;
	49	}
	50
	51	veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
	52	veth.h_vlan_encapsulated_proto = skb->protocol;
	53
	54	vlanh += offset;
	55
	56	vlan_len = min_t(u8, len, VLAN_ETH_HLEN - offset);
	57	memcpy(dst_u8, vlanh, vlan_len);
	58
	59	len -= vlan_len;
	60	if (!len)
	61	return true;
	62
	63	dst_u8 += vlan_len;
	64	skip:
	65	return skb_copy_bits(skb, offset + mac_off, dst_u8, len) == 0;
	66	}
	67
96518518	68	static void nft_payload_eval(const struct nft_expr *expr,
a55e22e9	69	struct nft_regs *regs,
96518518 PM	70	const struct nft_pktinfo *pkt)
	71	{
	72	const struct nft_payload *priv = nft_expr_priv(expr);
	73	const struct sk_buff *skb = pkt->skb;
49499c3e	74	u32 *dest = &regs->data[priv->dreg];
96518518 PM	75	int offset;
96518518 PM	76
8cfd23e6	77	dest[priv->len / NFT_REG32_SIZE] = 0;
96518518 PM	78	switch (priv->base) {
	79	case NFT_PAYLOAD_LL_HEADER:
	80	if (!skb_mac_header_was_set(skb))
	81	goto err;
8cfd23e6 FW	82
	83	if (skb_vlan_tag_present(skb)) {
	84	if (!nft_payload_copy_vlan(dest, skb,
	85	priv->offset, priv->len))
	86	goto err;
	87	return;
	88	}
96518518 PM	89	offset = skb_mac_header(skb) - skb->data;
	90	break;
	91	case NFT_PAYLOAD_NETWORK_HEADER:
	92	offset = skb_network_offset(skb);
	93	break;
	94	case NFT_PAYLOAD_TRANSPORT_HEADER:
c54032e0	95	offset = pkt->xt.thoff;
96518518 PM	96	break;
	97	default:
	98	BUG();
	99	}
	100	offset += priv->offset;
	101
fad136ea	102	if (skb_copy_bits(skb, offset, dest, priv->len) < 0)
96518518 PM	103	goto err;
	104	return;
	105	err:
a55e22e9	106	regs->verdict.code = NFT_BREAK;
96518518 PM	107	}
	108
	109	static const struct nla_policy nft_payload_policy[NFTA_PAYLOAD_MAX + 1] = {
	110	[NFTA_PAYLOAD_DREG] = { .type = NLA_U32 },
	111	[NFTA_PAYLOAD_BASE] = { .type = NLA_U32 },
	112	[NFTA_PAYLOAD_OFFSET] = { .type = NLA_U32 },
	113	[NFTA_PAYLOAD_LEN] = { .type = NLA_U32 },
	114	};
	115
	116	static int nft_payload_init(const struct nft_ctx *ctx,
	117	const struct nft_expr *expr,
	118	const struct nlattr * const tb[])
	119	{
	120	struct nft_payload *priv = nft_expr_priv(expr);
96518518	121
c29b72e0	122	priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
96518518 PM	123	priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
96518518 PM	124	priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
b1c96ed3	125	priv->dreg = nft_parse_register(tb[NFTA_PAYLOAD_DREG]);
96518518	126
1ec10212 PM	127	return nft_validate_register_store(ctx, priv->dreg, NULL,
1ec10212 PM	128	NFT_DATA_VALUE, priv->len);
96518518 PM	129	}
	130
	131	static int nft_payload_dump(struct sk_buff skb, const struct nft_expr expr)
	132	{
	133	const struct nft_payload *priv = nft_expr_priv(expr);
	134
b1c96ed3	135	if (nft_dump_register(skb, NFTA_PAYLOAD_DREG, priv->dreg) \|\|
96518518 PM	136	nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) \|\|
	137	nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) \|\|
	138	nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len)))
	139	goto nla_put_failure;
	140	return 0;
	141
	142	nla_put_failure:
	143	return -1;
	144	}
	145
ef1f7df9 PM	146	static struct nft_expr_type nft_payload_type;
	147	static const struct nft_expr_ops nft_payload_ops = {
	148	.type = &nft_payload_type,
96518518	149	.size = NFT_EXPR_SIZE(sizeof(struct nft_payload)),
96518518 PM	150	.eval = nft_payload_eval,
	151	.init = nft_payload_init,
	152	.dump = nft_payload_dump,
ef1f7df9 PM	153	};
ef1f7df9 PM	154
c29b72e0 PM	155	const struct nft_expr_ops nft_payload_fast_ops = {
	156	.type = &nft_payload_type,
	157	.size = NFT_EXPR_SIZE(sizeof(struct nft_payload)),
	158	.eval = nft_payload_eval,
	159	.init = nft_payload_init,
	160	.dump = nft_payload_dump,
	161	};
	162
0ca743a5 PNA	163	static const struct nft_expr_ops *
	164	nft_payload_select_ops(const struct nft_ctx *ctx,
	165	const struct nlattr * const tb[])
c29b72e0 PM	166	{
	167	enum nft_payload_bases base;
	168	unsigned int offset, len;
	169
	170	if (tb[NFTA_PAYLOAD_DREG] == NULL \|\|
	171	tb[NFTA_PAYLOAD_BASE] == NULL \|\|
	172	tb[NFTA_PAYLOAD_OFFSET] == NULL \|\|
	173	tb[NFTA_PAYLOAD_LEN] == NULL)
	174	return ERR_PTR(-EINVAL);
	175
	176	base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
	177	switch (base) {
	178	case NFT_PAYLOAD_LL_HEADER:
	179	case NFT_PAYLOAD_NETWORK_HEADER:
	180	case NFT_PAYLOAD_TRANSPORT_HEADER:
	181	break;
	182	default:
	183	return ERR_PTR(-EOPNOTSUPP);
	184	}
	185
	186	offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
45d9bcda	187	len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
c29b72e0	188
f627ed91 NA	189	if (len <= 4 && is_power_of_2(len) && IS_ALIGNED(offset, len) &&
f627ed91 NA	190	base != NFT_PAYLOAD_LL_HEADER)
c29b72e0 PM	191	return &nft_payload_fast_ops;
	192	else
	193	return &nft_payload_ops;
	194	}
	195
ef1f7df9 PM	196	static struct nft_expr_type nft_payload_type __read_mostly = {
ef1f7df9 PM	197	.name = "payload",
c29b72e0	198	.select_ops = nft_payload_select_ops,
96518518 PM	199	.policy = nft_payload_policy,
96518518 PM	200	.maxattr = NFTA_PAYLOAD_MAX,
ef1f7df9	201	.owner = THIS_MODULE,
96518518 PM	202	};
	203
	204	int __init nft_payload_module_init(void)
	205	{
ef1f7df9	206	return nft_register_expr(&nft_payload_type);
96518518 PM	207	}
	208
	209	void nft_payload_module_exit(void)
	210	{
ef1f7df9	211	nft_unregister_expr(&nft_payload_type);
96518518	212	}