[deliverable/linux.git] / net / bridge / netfilter / nf_tables_bridge.c

/*
 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
 * Copyright (c) 2013 Pablo Neira Ayuso <pablo@netfilter.org>
 *
 * 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/init.h>
#include <linux/module.h>
#include <linux/netfilter_bridge.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_bridge.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <net/netfilter/nf_tables_ipv4.h>
#include <net/netfilter/nf_tables_ipv6.h>

int nft_bridge_iphdr_validate(struct sk_buff *skb)
{
	struct iphdr *iph;
	u32 len;

	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
		return 0;

	iph = ip_hdr(skb);
	if (iph->ihl < 5 || iph->version != 4)
		return 0;

	len = ntohs(iph->tot_len);
	if (skb->len < len)
		return 0;
	else if (len < (iph->ihl*4))
		return 0;

	if (!pskb_may_pull(skb, iph->ihl*4))
		return 0;

	return 1;
}
EXPORT_SYMBOL_GPL(nft_bridge_iphdr_validate);

int nft_bridge_ip6hdr_validate(struct sk_buff *skb)
{
	struct ipv6hdr *hdr;
	u32 pkt_len;

	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
		return 0;

	hdr = ipv6_hdr(skb);
	if (hdr->version != 6)
		return 0;

	pkt_len = ntohs(hdr->payload_len);
	if (pkt_len + sizeof(struct ipv6hdr) > skb->len)
		return 0;

	return 1;
}
EXPORT_SYMBOL_GPL(nft_bridge_ip6hdr_validate);

static inline void nft_bridge_set_pktinfo_ipv4(struct nft_pktinfo *pkt,
					       const struct nf_hook_ops *ops,
					       struct sk_buff *skb,
					       const struct net_device *in,
					       const struct net_device *out)
{
	if (nft_bridge_iphdr_validate(skb))
		nft_set_pktinfo_ipv4(pkt, ops, skb, in, out);
	else
		nft_set_pktinfo(pkt, ops, skb, in, out);
}

static inline void nft_bridge_set_pktinfo_ipv6(struct nft_pktinfo *pkt,
					      const struct nf_hook_ops *ops,
					      struct sk_buff *skb,
					      const struct net_device *in,
					      const struct net_device *out)
{
#if IS_ENABLED(CONFIG_IPV6)
	if (nft_bridge_ip6hdr_validate(skb) &&
	    nft_set_pktinfo_ipv6(pkt, ops, skb, in, out) == 0)
		return;
#endif
	nft_set_pktinfo(pkt, ops, skb, in, out);
}

static unsigned int
nft_do_chain_bridge(const struct nf_hook_ops *ops,
		    struct sk_buff *skb,
		    const struct nf_hook_state *state)
{
	struct nft_pktinfo pkt;

	switch (eth_hdr(skb)->h_proto) {
	case htons(ETH_P_IP):
		nft_bridge_set_pktinfo_ipv4(&pkt, ops, skb, state->in, state->out);
		break;
	case htons(ETH_P_IPV6):
		nft_bridge_set_pktinfo_ipv6(&pkt, ops, skb, state->in, state->out);
		break;
	default:
		nft_set_pktinfo(&pkt, ops, skb, state->in, state->out);
		break;
	}

	return nft_do_chain(&pkt, ops);
}

static struct nft_af_info nft_af_bridge __read_mostly = {
	.family		= NFPROTO_BRIDGE,
	.nhooks		= NF_BR_NUMHOOKS,
	.owner		= THIS_MODULE,
	.nops		= 1,
	.hooks		= {
		[NF_BR_PRE_ROUTING]	= nft_do_chain_bridge,
		[NF_BR_LOCAL_IN]	= nft_do_chain_bridge,
		[NF_BR_FORWARD]		= nft_do_chain_bridge,
		[NF_BR_LOCAL_OUT]	= nft_do_chain_bridge,
		[NF_BR_POST_ROUTING]	= nft_do_chain_bridge,
	},
};

static int nf_tables_bridge_init_net(struct net *net)
{
	net->nft.bridge = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL);
	if (net->nft.bridge == NULL)
		return -ENOMEM;

	memcpy(net->nft.bridge, &nft_af_bridge, sizeof(nft_af_bridge));

	if (nft_register_afinfo(net, net->nft.bridge) < 0)
		goto err;

	return 0;
err:
	kfree(net->nft.bridge);
	return -ENOMEM;
}

static void nf_tables_bridge_exit_net(struct net *net)
{
	nft_unregister_afinfo(net->nft.bridge);
	kfree(net->nft.bridge);
}

static struct pernet_operations nf_tables_bridge_net_ops = {
	.init	= nf_tables_bridge_init_net,
	.exit	= nf_tables_bridge_exit_net,
};

static const struct nf_chain_type filter_bridge = {
	.name		= "filter",
	.type		= NFT_CHAIN_T_DEFAULT,
	.family		= NFPROTO_BRIDGE,
	.owner		= THIS_MODULE,
	.hook_mask	= (1 << NF_BR_PRE_ROUTING) |
			  (1 << NF_BR_LOCAL_IN) |
			  (1 << NF_BR_FORWARD) |
			  (1 << NF_BR_LOCAL_OUT) |
			  (1 << NF_BR_POST_ROUTING),
};

static int __init nf_tables_bridge_init(void)
{
	int ret;

	nft_register_chain_type(&filter_bridge);
	ret = register_pernet_subsys(&nf_tables_bridge_net_ops);
	if (ret < 0)
		nft_unregister_chain_type(&filter_bridge);

	return ret;
}

static void __exit nf_tables_bridge_exit(void)
{
	unregister_pernet_subsys(&nf_tables_bridge_net_ops);
	nft_unregister_chain_type(&filter_bridge);
}

module_init(nf_tables_bridge_init);
module_exit(nf_tables_bridge_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_ALIAS_NFT_FAMILY(AF_BRIDGE);
Commit	Line	Data
96518518 PM	1	/*
96518518 PM	2	* Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
46413825	3	* Copyright (c) 2013 Pablo Neira Ayuso <pablo@netfilter.org>
96518518 PM	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*
	9	* Development of this code funded by Astaro AG (http://www.astaro.com/)
	10	*/
	11
	12	#include <linux/init.h>
	13	#include <linux/module.h>
	14	#include <linux/netfilter_bridge.h>
	15	#include <net/netfilter/nf_tables.h>
68b0faa8 AN	16	#include <net/netfilter/nf_tables_bridge.h>
	17	#include <linux/ip.h>
	18	#include <linux/ipv6.h>
1b63d4b9 AN	19	#include <net/netfilter/nf_tables_ipv4.h>
1b63d4b9 AN	20	#include <net/netfilter/nf_tables_ipv6.h>
68b0faa8 AN	21
	22	int nft_bridge_iphdr_validate(struct sk_buff *skb)
	23	{
	24	struct iphdr *iph;
	25	u32 len;
	26
	27	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
	28	return 0;
	29
	30	iph = ip_hdr(skb);
	31	if (iph->ihl < 5 \|\| iph->version != 4)
	32	return 0;
	33
	34	len = ntohs(iph->tot_len);
	35	if (skb->len < len)
	36	return 0;
	37	else if (len < (iph->ihl*4))
	38	return 0;
	39
	40	if (!pskb_may_pull(skb, iph->ihl*4))
	41	return 0;
	42
	43	return 1;
	44	}
	45	EXPORT_SYMBOL_GPL(nft_bridge_iphdr_validate);
	46
	47	int nft_bridge_ip6hdr_validate(struct sk_buff *skb)
	48	{
	49	struct ipv6hdr *hdr;
	50	u32 pkt_len;
	51
	52	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
	53	return 0;
	54
	55	hdr = ipv6_hdr(skb);
	56	if (hdr->version != 6)
	57	return 0;
	58
	59	pkt_len = ntohs(hdr->payload_len);
	60	if (pkt_len + sizeof(struct ipv6hdr) > skb->len)
	61	return 0;
	62
	63	return 1;
	64	}
	65	EXPORT_SYMBOL_GPL(nft_bridge_ip6hdr_validate);
96518518	66
1b63d4b9 AN	67	static inline void nft_bridge_set_pktinfo_ipv4(struct nft_pktinfo *pkt,
	68	const struct nf_hook_ops *ops,
	69	struct sk_buff *skb,
	70	const struct net_device *in,
	71	const struct net_device *out)
	72	{
	73	if (nft_bridge_iphdr_validate(skb))
	74	nft_set_pktinfo_ipv4(pkt, ops, skb, in, out);
	75	else
	76	nft_set_pktinfo(pkt, ops, skb, in, out);
	77	}
	78
	79	static inline void nft_bridge_set_pktinfo_ipv6(struct nft_pktinfo *pkt,
	80	const struct nf_hook_ops *ops,
	81	struct sk_buff *skb,
	82	const struct net_device *in,
	83	const struct net_device *out)
	84	{
	85	#if IS_ENABLED(CONFIG_IPV6)
	86	if (nft_bridge_ip6hdr_validate(skb) &&
	87	nft_set_pktinfo_ipv6(pkt, ops, skb, in, out) == 0)
	88	return;
	89	#endif
	90	nft_set_pktinfo(pkt, ops, skb, in, out);
	91	}
	92
3b088c4b PM	93	static unsigned int
	94	nft_do_chain_bridge(const struct nf_hook_ops *ops,
	95	struct sk_buff *skb,
238e54c9	96	const struct nf_hook_state *state)
3b088c4b PM	97	{
	98	struct nft_pktinfo pkt;
	99
1b63d4b9 AN	100	switch (eth_hdr(skb)->h_proto) {
1b63d4b9 AN	101	case htons(ETH_P_IP):
238e54c9	102	nft_bridge_set_pktinfo_ipv4(&pkt, ops, skb, state->in, state->out);
1b63d4b9 AN	103	break;
1b63d4b9 AN	104	case htons(ETH_P_IPV6):
238e54c9	105	nft_bridge_set_pktinfo_ipv6(&pkt, ops, skb, state->in, state->out);
1b63d4b9 AN	106	break;
1b63d4b9 AN	107	default:
238e54c9	108	nft_set_pktinfo(&pkt, ops, skb, state->in, state->out);
1b63d4b9 AN	109	break;
1b63d4b9 AN	110	}
3b088c4b	111
3876d22d	112	return nft_do_chain(&pkt, ops);
3b088c4b PM	113	}
3b088c4b PM	114
96518518 PM	115	static struct nft_af_info nft_af_bridge __read_mostly = {
	116	.family = NFPROTO_BRIDGE,
	117	.nhooks = NF_BR_NUMHOOKS,
	118	.owner = THIS_MODULE,
115a60b1	119	.nops = 1,
3b088c4b	120	.hooks = {
36d2af59	121	[NF_BR_PRE_ROUTING] = nft_do_chain_bridge,
3b088c4b PM	122	[NF_BR_LOCAL_IN] = nft_do_chain_bridge,
	123	[NF_BR_FORWARD] = nft_do_chain_bridge,
	124	[NF_BR_LOCAL_OUT] = nft_do_chain_bridge,
36d2af59	125	[NF_BR_POST_ROUTING] = nft_do_chain_bridge,
3b088c4b	126	},
96518518 PM	127	};
96518518 PM	128
99633ab2 PNA	129	static int nf_tables_bridge_init_net(struct net *net)
	130	{
	131	net->nft.bridge = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL);
	132	if (net->nft.bridge == NULL)
	133	return -ENOMEM;
	134
	135	memcpy(net->nft.bridge, &nft_af_bridge, sizeof(nft_af_bridge));
	136
	137	if (nft_register_afinfo(net, net->nft.bridge) < 0)
	138	goto err;
	139
	140	return 0;
	141	err:
	142	kfree(net->nft.bridge);
	143	return -ENOMEM;
	144	}
	145
	146	static void nf_tables_bridge_exit_net(struct net *net)
	147	{
	148	nft_unregister_afinfo(net->nft.bridge);
	149	kfree(net->nft.bridge);
	150	}
	151
	152	static struct pernet_operations nf_tables_bridge_net_ops = {
	153	.init = nf_tables_bridge_init_net,
	154	.exit = nf_tables_bridge_exit_net,
	155	};
	156
2a37d755	157	static const struct nf_chain_type filter_bridge = {
46413825 PNA	158	.name = "filter",
46413825 PNA	159	.type = NFT_CHAIN_T_DEFAULT,
fa2c1de0 PM	160	.family = NFPROTO_BRIDGE,
fa2c1de0 PM	161	.owner = THIS_MODULE,
4d87716c PNA	162	.hook_mask = (1 << NF_BR_PRE_ROUTING) \|
4d87716c PNA	163	(1 << NF_BR_LOCAL_IN) \|
46413825	164	(1 << NF_BR_FORWARD) \|
4d87716c PNA	165	(1 << NF_BR_LOCAL_OUT) \|
4d87716c PNA	166	(1 << NF_BR_POST_ROUTING),
46413825 PNA	167	};
46413825 PNA	168
96518518 PM	169	static int __init nf_tables_bridge_init(void)
96518518 PM	170	{
46413825 PNA	171	int ret;
	172
	173	nft_register_chain_type(&filter_bridge);
	174	ret = register_pernet_subsys(&nf_tables_bridge_net_ops);
	175	if (ret < 0)
	176	nft_unregister_chain_type(&filter_bridge);
	177
	178	return ret;
96518518 PM	179	}
	180
	181	static void __exit nf_tables_bridge_exit(void)
	182	{
46413825 PNA	183	unregister_pernet_subsys(&nf_tables_bridge_net_ops);
46413825 PNA	184	nft_unregister_chain_type(&filter_bridge);
96518518 PM	185	}
	186
	187	module_init(nf_tables_bridge_init);
	188	module_exit(nf_tables_bridge_exit);
	189
	190	MODULE_LICENSE("GPL");
	191	MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
	192	MODULE_ALIAS_NFT_FAMILY(AF_BRIDGE);