[net-next-2.6.git] / net / bridge / netfilter / ebt_ip.c

/*
 *  ebt_ip
 *
 *	Authors:
 *	Bart De Schuymer <bdschuym@pandora.be>
 *
 *  April, 2002
 *
 *  Changes:
 *    added ip-sport and ip-dport
 *    Innominate Security Technologies AG <mhopf@innominate.com>
 *    September, 2002
 */
#include <linux/ip.h>
#include <net/ip.h>
#include <linux/in.h>
#include <linux/module.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_ip.h>

struct tcpudphdr {
	__be16 src;
	__be16 dst;
};

static bool ebt_filter_ip(const struct sk_buff *skb,
   const struct net_device *in,
   const struct net_device *out, const void *data,
   unsigned int datalen)
{
	const struct ebt_ip_info *info = data;
	const struct iphdr *ih;
	struct iphdr _iph;
	const struct tcpudphdr *pptr;
	struct tcpudphdr _ports;

	ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
	if (ih == NULL)
		return false;
	if (info->bitmask & EBT_IP_TOS &&
	   FWINV(info->tos != ih->tos, EBT_IP_TOS))
		return false;
	if (info->bitmask & EBT_IP_SOURCE &&
	   FWINV((ih->saddr & info->smsk) !=
	   info->saddr, EBT_IP_SOURCE))
		return false;
	if ((info->bitmask & EBT_IP_DEST) &&
	   FWINV((ih->daddr & info->dmsk) !=
	   info->daddr, EBT_IP_DEST))
		return false;
	if (info->bitmask & EBT_IP_PROTO) {
		if (FWINV(info->protocol != ih->protocol, EBT_IP_PROTO))
			return false;
		if (!(info->bitmask & EBT_IP_DPORT) &&
		    !(info->bitmask & EBT_IP_SPORT))
			return true;
		if (ntohs(ih->frag_off) & IP_OFFSET)
			return false;
		pptr = skb_header_pointer(skb, ih->ihl*4,
					  sizeof(_ports), &_ports);
		if (pptr == NULL)
			return false;
		if (info->bitmask & EBT_IP_DPORT) {
			u32 dst = ntohs(pptr->dst);
			if (FWINV(dst < info->dport[0] ||
				  dst > info->dport[1],
				  EBT_IP_DPORT))
			return false;
		}
		if (info->bitmask & EBT_IP_SPORT) {
			u32 src = ntohs(pptr->src);
			if (FWINV(src < info->sport[0] ||
				  src > info->sport[1],
				  EBT_IP_SPORT))
			return false;
		}
	}
	return true;
}

static bool ebt_ip_check(const char *tablename, unsigned int hookmask,
   const struct ebt_entry *e, void *data, unsigned int datalen)
{
	const struct ebt_ip_info *info = data;

	if (e->ethproto != htons(ETH_P_IP) ||
	   e->invflags & EBT_IPROTO)
		return false;
	if (info->bitmask & ~EBT_IP_MASK || info->invflags & ~EBT_IP_MASK)
		return false;
	if (info->bitmask & (EBT_IP_DPORT | EBT_IP_SPORT)) {
		if (info->invflags & EBT_IP_PROTO)
			return false;
		if (info->protocol != IPPROTO_TCP &&
		    info->protocol != IPPROTO_UDP &&
		    info->protocol != IPPROTO_UDPLITE &&
		    info->protocol != IPPROTO_SCTP &&
		    info->protocol != IPPROTO_DCCP)
			 return false;
	}
	if (info->bitmask & EBT_IP_DPORT && info->dport[0] > info->dport[1])
		return false;
	if (info->bitmask & EBT_IP_SPORT && info->sport[0] > info->sport[1])
		return false;
	return true;
}

static struct ebt_match filter_ip __read_mostly = {
	.name		= EBT_IP_MATCH,
	.revision	= 0,
	.family		= NFPROTO_BRIDGE,
	.match		= ebt_filter_ip,
	.check		= ebt_ip_check,
	.matchsize	= XT_ALIGN(sizeof(struct ebt_ip_info)),
	.me		= THIS_MODULE,
};

static int __init ebt_ip_init(void)
{
	return ebt_register_match(&filter_ip);
}

static void __exit ebt_ip_fini(void)
{
	ebt_unregister_match(&filter_ip);
}

module_init(ebt_ip_init);
module_exit(ebt_ip_fini);
MODULE_DESCRIPTION("Ebtables: IPv4 protocol packet match");
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* ebt_ip
	3	*
	4	* Authors:
	5	* Bart De Schuymer <bdschuym@pandora.be>
	6	*
	7	* April, 2002
	8	*
	9	* Changes:
	10	* added ip-sport and ip-dport
	11	* Innominate Security Technologies AG <mhopf@innominate.com>
	12	* September, 2002
	13	*/
1da177e4	14	#include <linux/ip.h>
8a4c8a96	15	#include <net/ip.h>
1da177e4 LT	16	#include <linux/in.h>
1da177e4 LT	17	#include <linux/module.h>
18219d3f JE	18	#include <linux/netfilter/x_tables.h>
	19	#include <linux/netfilter_bridge/ebtables.h>
	20	#include <linux/netfilter_bridge/ebt_ip.h>
1da177e4 LT	21
1da177e4 LT	22	struct tcpudphdr {
47c183fa AV	23	__be16 src;
47c183fa AV	24	__be16 dst;
1da177e4 LT	25	};
1da177e4 LT	26
8cc784ee JE	27	static bool ebt_filter_ip(const struct sk_buff *skb,
8cc784ee JE	28	const struct net_device *in,
1da177e4 LT	29	const struct net_device out, const void data,
	30	unsigned int datalen)
	31	{
abfdf1c4 JE	32	const struct ebt_ip_info *info = data;
	33	const struct iphdr *ih;
	34	struct iphdr _iph;
	35	const struct tcpudphdr *pptr;
	36	struct tcpudphdr _ports;
1da177e4 LT	37
	38	ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
	39	if (ih == NULL)
8cc784ee	40	return false;
1da177e4 LT	41	if (info->bitmask & EBT_IP_TOS &&
1da177e4 LT	42	FWINV(info->tos != ih->tos, EBT_IP_TOS))
8cc784ee	43	return false;
1da177e4 LT	44	if (info->bitmask & EBT_IP_SOURCE &&
	45	FWINV((ih->saddr & info->smsk) !=
	46	info->saddr, EBT_IP_SOURCE))
8cc784ee	47	return false;
1da177e4 LT	48	if ((info->bitmask & EBT_IP_DEST) &&
	49	FWINV((ih->daddr & info->dmsk) !=
	50	info->daddr, EBT_IP_DEST))
8cc784ee	51	return false;
1da177e4 LT	52	if (info->bitmask & EBT_IP_PROTO) {
1da177e4 LT	53	if (FWINV(info->protocol != ih->protocol, EBT_IP_PROTO))
8cc784ee	54	return false;
1da177e4 LT	55	if (!(info->bitmask & EBT_IP_DPORT) &&
1da177e4 LT	56	!(info->bitmask & EBT_IP_SPORT))
8cc784ee	57	return true;
8a4c8a96	58	if (ntohs(ih->frag_off) & IP_OFFSET)
8cc784ee	59	return false;
1da177e4 LT	60	pptr = skb_header_pointer(skb, ih->ihl*4,
	61	sizeof(_ports), &_ports);
	62	if (pptr == NULL)
8cc784ee	63	return false;
1da177e4 LT	64	if (info->bitmask & EBT_IP_DPORT) {
	65	u32 dst = ntohs(pptr->dst);
	66	if (FWINV(dst < info->dport[0] \|\|
9d6f229f YH	67	dst > info->dport[1],
9d6f229f YH	68	EBT_IP_DPORT))
8cc784ee	69	return false;
1da177e4 LT	70	}
	71	if (info->bitmask & EBT_IP_SPORT) {
	72	u32 src = ntohs(pptr->src);
	73	if (FWINV(src < info->sport[0] \|\|
9d6f229f YH	74	src > info->sport[1],
9d6f229f YH	75	EBT_IP_SPORT))
8cc784ee	76	return false;
1da177e4 LT	77	}
1da177e4 LT	78	}
8cc784ee	79	return true;
1da177e4 LT	80	}
1da177e4 LT	81
19eda879	82	static bool ebt_ip_check(const char *tablename, unsigned int hookmask,
1da177e4 LT	83	const struct ebt_entry e, void data, unsigned int datalen)
1da177e4 LT	84	{
abfdf1c4	85	const struct ebt_ip_info *info = data;
1da177e4	86
1da177e4 LT	87	if (e->ethproto != htons(ETH_P_IP) \|\|
1da177e4 LT	88	e->invflags & EBT_IPROTO)
19eda879	89	return false;
1da177e4	90	if (info->bitmask & ~EBT_IP_MASK \|\| info->invflags & ~EBT_IP_MASK)
19eda879	91	return false;
1da177e4 LT	92	if (info->bitmask & (EBT_IP_DPORT \| EBT_IP_SPORT)) {
1da177e4 LT	93	if (info->invflags & EBT_IP_PROTO)
19eda879	94	return false;
1da177e4	95	if (info->protocol != IPPROTO_TCP &&
ab67a4d5	96	info->protocol != IPPROTO_UDP &&
a8d0f952	97	info->protocol != IPPROTO_UDPLITE &&
ab67a4d5 PM	98	info->protocol != IPPROTO_SCTP &&
ab67a4d5 PM	99	info->protocol != IPPROTO_DCCP)
19eda879	100	return false;
1da177e4 LT	101	}
1da177e4 LT	102	if (info->bitmask & EBT_IP_DPORT && info->dport[0] > info->dport[1])
19eda879	103	return false;
1da177e4	104	if (info->bitmask & EBT_IP_SPORT && info->sport[0] > info->sport[1])
19eda879 JE	105	return false;
19eda879 JE	106	return true;
1da177e4 LT	107	}
1da177e4 LT	108
30083c95	109	static struct ebt_match filter_ip __read_mostly = {
1da177e4	110	.name = EBT_IP_MATCH,
001a18d3 JE	111	.revision = 0,
001a18d3 JE	112	.family = NFPROTO_BRIDGE,
1da177e4 LT	113	.match = ebt_filter_ip,
1da177e4 LT	114	.check = ebt_ip_check,
18219d3f	115	.matchsize = XT_ALIGN(sizeof(struct ebt_ip_info)),
1da177e4 LT	116	.me = THIS_MODULE,
	117	};
	118
65b4b4e8	119	static int __init ebt_ip_init(void)
1da177e4 LT	120	{
	121	return ebt_register_match(&filter_ip);
	122	}
	123
65b4b4e8	124	static void __exit ebt_ip_fini(void)
1da177e4 LT	125	{
	126	ebt_unregister_match(&filter_ip);
	127	}
	128
65b4b4e8 AM	129	module_init(ebt_ip_init);
65b4b4e8 AM	130	module_exit(ebt_ip_fini);
f776c4cd	131	MODULE_DESCRIPTION("Ebtables: IPv4 protocol packet match");
1da177e4	132	MODULE_LICENSE("GPL");