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

/*
 *  ebt_stp
 *
 *	Authors:
 *	Bart De Schuymer <bdschuym@pandora.be>
 *	Stephen Hemminger <shemminger@osdl.org>
 *
 *  July, 2003
 */
#include <linux/etherdevice.h>
#include <linux/module.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_stp.h>

#define BPDU_TYPE_CONFIG 0
#define BPDU_TYPE_TCN 0x80

struct stp_header {
	u8 dsap;
	u8 ssap;
	u8 ctrl;
	u8 pid;
	u8 vers;
	u8 type;
};

struct stp_config_pdu {
	u8 flags;
	u8 root[8];
	u8 root_cost[4];
	u8 sender[8];
	u8 port[2];
	u8 msg_age[2];
	u8 max_age[2];
	u8 hello_time[2];
	u8 forward_delay[2];
};

#define NR16(p) (p[0] << 8 | p[1])
#define NR32(p) ((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3])

static bool ebt_filter_config(const struct ebt_stp_info *info,
			      const struct stp_config_pdu *stpc)
{
	const struct ebt_stp_config_info *c;
	u16 v16;
	u32 v32;

	c = &info->config;
	if ((info->bitmask & EBT_STP_FLAGS) &&
	    NF_INVF(info, EBT_STP_FLAGS, c->flags != stpc->flags))
		return false;
	if (info->bitmask & EBT_STP_ROOTPRIO) {
		v16 = NR16(stpc->root);
		if (NF_INVF(info, EBT_STP_ROOTPRIO,
			    v16 < c->root_priol || v16 > c->root_priou))
			return false;
	}
	if (info->bitmask & EBT_STP_ROOTADDR) {
		if (NF_INVF(info, EBT_STP_ROOTADDR,
			    !ether_addr_equal_masked(&stpc->root[2],
						     c->root_addr,
						     c->root_addrmsk)))
			return false;
	}
	if (info->bitmask & EBT_STP_ROOTCOST) {
		v32 = NR32(stpc->root_cost);
		if (NF_INVF(info, EBT_STP_ROOTCOST,
			    v32 < c->root_costl || v32 > c->root_costu))
			return false;
	}
	if (info->bitmask & EBT_STP_SENDERPRIO) {
		v16 = NR16(stpc->sender);
		if (NF_INVF(info, EBT_STP_SENDERPRIO,
			    v16 < c->sender_priol || v16 > c->sender_priou))
			return false;
	}
	if (info->bitmask & EBT_STP_SENDERADDR) {
		if (NF_INVF(info, EBT_STP_SENDERADDR,
			    !ether_addr_equal_masked(&stpc->sender[2],
						     c->sender_addr,
						     c->sender_addrmsk)))
			return false;
	}
	if (info->bitmask & EBT_STP_PORT) {
		v16 = NR16(stpc->port);
		if (NF_INVF(info, EBT_STP_PORT,
			    v16 < c->portl || v16 > c->portu))
			return false;
	}
	if (info->bitmask & EBT_STP_MSGAGE) {
		v16 = NR16(stpc->msg_age);
		if (NF_INVF(info, EBT_STP_MSGAGE,
			    v16 < c->msg_agel || v16 > c->msg_ageu))
			return false;
	}
	if (info->bitmask & EBT_STP_MAXAGE) {
		v16 = NR16(stpc->max_age);
		if (NF_INVF(info, EBT_STP_MAXAGE,
			    v16 < c->max_agel || v16 > c->max_ageu))
			return false;
	}
	if (info->bitmask & EBT_STP_HELLOTIME) {
		v16 = NR16(stpc->hello_time);
		if (NF_INVF(info, EBT_STP_HELLOTIME,
			    v16 < c->hello_timel || v16 > c->hello_timeu))
			return false;
	}
	if (info->bitmask & EBT_STP_FWDD) {
		v16 = NR16(stpc->forward_delay);
		if (NF_INVF(info, EBT_STP_FWDD,
			    v16 < c->forward_delayl || v16 > c->forward_delayu))
			return false;
	}
	return true;
}

static bool
ebt_stp_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
	const struct ebt_stp_info *info = par->matchinfo;
	const struct stp_header *sp;
	struct stp_header _stph;
	const u8 header[6] = {0x42, 0x42, 0x03, 0x00, 0x00, 0x00};

	sp = skb_header_pointer(skb, 0, sizeof(_stph), &_stph);
	if (sp == NULL)
		return false;

	/* The stp code only considers these */
	if (memcmp(sp, header, sizeof(header)))
		return false;

	if ((info->bitmask & EBT_STP_TYPE) &&
	    NF_INVF(info, EBT_STP_TYPE, info->type != sp->type))
		return false;

	if (sp->type == BPDU_TYPE_CONFIG &&
	    info->bitmask & EBT_STP_CONFIG_MASK) {
		const struct stp_config_pdu *st;
		struct stp_config_pdu _stpc;

		st = skb_header_pointer(skb, sizeof(_stph),
					sizeof(_stpc), &_stpc);
		if (st == NULL)
			return false;
		return ebt_filter_config(info, st);
	}
	return true;
}

static int ebt_stp_mt_check(const struct xt_mtchk_param *par)
{
	const struct ebt_stp_info *info = par->matchinfo;
	const u8 bridge_ula[6] = {0x01, 0x80, 0xc2, 0x00, 0x00, 0x00};
	const u8 msk[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
	const struct ebt_entry *e = par->entryinfo;

	if (info->bitmask & ~EBT_STP_MASK || info->invflags & ~EBT_STP_MASK ||
	    !(info->bitmask & EBT_STP_MASK))
		return -EINVAL;
	/* Make sure the match only receives stp frames */
	if (!par->nft_compat &&
	    (!ether_addr_equal(e->destmac, bridge_ula) ||
	     !ether_addr_equal(e->destmsk, msk) ||
	     !(e->bitmask & EBT_DESTMAC)))
		return -EINVAL;

	return 0;
}

static struct xt_match ebt_stp_mt_reg __read_mostly = {
	.name		= "stp",
	.revision	= 0,
	.family		= NFPROTO_BRIDGE,
	.match		= ebt_stp_mt,
	.checkentry	= ebt_stp_mt_check,
	.matchsize	= sizeof(struct ebt_stp_info),
	.me		= THIS_MODULE,
};

static int __init ebt_stp_init(void)
{
	return xt_register_match(&ebt_stp_mt_reg);
}

static void __exit ebt_stp_fini(void)
{
	xt_unregister_match(&ebt_stp_mt_reg);
}

module_init(ebt_stp_init);
module_exit(ebt_stp_fini);
MODULE_DESCRIPTION("Ebtables: Spanning Tree Protocol packet match");
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* ebt_stp
	3	*
	4	* Authors:
	5	* Bart De Schuymer <bdschuym@pandora.be>
	6	* Stephen Hemminger <shemminger@osdl.org>
	7	*
	8	* July, 2003
	9	*/
82bf7e97	10	#include <linux/etherdevice.h>
1da177e4	11	#include <linux/module.h>
18219d3f JE	12	#include <linux/netfilter/x_tables.h>
	13	#include <linux/netfilter_bridge/ebtables.h>
	14	#include <linux/netfilter_bridge/ebt_stp.h>
1da177e4 LT	15
	16	#define BPDU_TYPE_CONFIG 0
	17	#define BPDU_TYPE_TCN 0x80
	18
	19	struct stp_header {
402f9030 TH	20	u8 dsap;
	21	u8 ssap;
	22	u8 ctrl;
	23	u8 pid;
	24	u8 vers;
	25	u8 type;
1da177e4 LT	26	};
	27
	28	struct stp_config_pdu {
402f9030 TH	29	u8 flags;
	30	u8 root[8];
	31	u8 root_cost[4];
	32	u8 sender[8];
	33	u8 port[2];
	34	u8 msg_age[2];
	35	u8 max_age[2];
	36	u8 hello_time[2];
	37	u8 forward_delay[2];
1da177e4 LT	38	};
	39
	40	#define NR16(p) (p[0] << 8 \| p[1])
	41	#define NR32(p) ((p[0] << 24) \| (p[1] << 16) \| (p[2] << 8) \| p[3])
	42
8cc784ee	43	static bool ebt_filter_config(const struct ebt_stp_info *info,
052a4bc4	44	const struct stp_config_pdu *stpc)
1da177e4	45	{
abfdf1c4	46	const struct ebt_stp_config_info *c;
402f9030 TH	47	u16 v16;
402f9030 TH	48	u32 v32;
1da177e4 LT	49
	50	c = &info->config;
	51	if ((info->bitmask & EBT_STP_FLAGS) &&
c37a2dfa	52	NF_INVF(info, EBT_STP_FLAGS, c->flags != stpc->flags))
8cc784ee	53	return false;
1da177e4 LT	54	if (info->bitmask & EBT_STP_ROOTPRIO) {
1da177e4 LT	55	v16 = NR16(stpc->root);
c37a2dfa JP	56	if (NF_INVF(info, EBT_STP_ROOTPRIO,
c37a2dfa JP	57	v16 < c->root_priol \|\| v16 > c->root_priou))
8cc784ee	58	return false;
1da177e4 LT	59	}
1da177e4 LT	60	if (info->bitmask & EBT_STP_ROOTADDR) {
c37a2dfa JP	61	if (NF_INVF(info, EBT_STP_ROOTADDR,
	62	!ether_addr_equal_masked(&stpc->root[2],
	63	c->root_addr,
	64	c->root_addrmsk)))
8cc784ee	65	return false;
1da177e4 LT	66	}
	67	if (info->bitmask & EBT_STP_ROOTCOST) {
	68	v32 = NR32(stpc->root_cost);
c37a2dfa JP	69	if (NF_INVF(info, EBT_STP_ROOTCOST,
c37a2dfa JP	70	v32 < c->root_costl \|\| v32 > c->root_costu))
8cc784ee	71	return false;
1da177e4 LT	72	}
	73	if (info->bitmask & EBT_STP_SENDERPRIO) {
	74	v16 = NR16(stpc->sender);
c37a2dfa JP	75	if (NF_INVF(info, EBT_STP_SENDERPRIO,
c37a2dfa JP	76	v16 < c->sender_priol \|\| v16 > c->sender_priou))
8cc784ee	77	return false;
1da177e4 LT	78	}
1da177e4 LT	79	if (info->bitmask & EBT_STP_SENDERADDR) {
c37a2dfa JP	80	if (NF_INVF(info, EBT_STP_SENDERADDR,
	81	!ether_addr_equal_masked(&stpc->sender[2],
	82	c->sender_addr,
	83	c->sender_addrmsk)))
8cc784ee	84	return false;
1da177e4 LT	85	}
	86	if (info->bitmask & EBT_STP_PORT) {
	87	v16 = NR16(stpc->port);
c37a2dfa JP	88	if (NF_INVF(info, EBT_STP_PORT,
c37a2dfa JP	89	v16 < c->portl \|\| v16 > c->portu))
8cc784ee	90	return false;
1da177e4 LT	91	}
	92	if (info->bitmask & EBT_STP_MSGAGE) {
	93	v16 = NR16(stpc->msg_age);
c37a2dfa JP	94	if (NF_INVF(info, EBT_STP_MSGAGE,
c37a2dfa JP	95	v16 < c->msg_agel \|\| v16 > c->msg_ageu))
8cc784ee	96	return false;
1da177e4 LT	97	}
	98	if (info->bitmask & EBT_STP_MAXAGE) {
	99	v16 = NR16(stpc->max_age);
c37a2dfa JP	100	if (NF_INVF(info, EBT_STP_MAXAGE,
c37a2dfa JP	101	v16 < c->max_agel \|\| v16 > c->max_ageu))
8cc784ee	102	return false;
1da177e4 LT	103	}
	104	if (info->bitmask & EBT_STP_HELLOTIME) {
	105	v16 = NR16(stpc->hello_time);
c37a2dfa JP	106	if (NF_INVF(info, EBT_STP_HELLOTIME,
c37a2dfa JP	107	v16 < c->hello_timel \|\| v16 > c->hello_timeu))
8cc784ee	108	return false;
1da177e4 LT	109	}
	110	if (info->bitmask & EBT_STP_FWDD) {
	111	v16 = NR16(stpc->forward_delay);
c37a2dfa JP	112	if (NF_INVF(info, EBT_STP_FWDD,
c37a2dfa JP	113	v16 < c->forward_delayl \|\| v16 > c->forward_delayu))
8cc784ee	114	return false;
1da177e4	115	}
8cc784ee	116	return true;
1da177e4 LT	117	}
1da177e4 LT	118
2d06d4a5	119	static bool
62fc8051	120	ebt_stp_mt(const struct sk_buff skb, struct xt_action_param par)
1da177e4	121	{
f7108a20	122	const struct ebt_stp_info *info = par->matchinfo;
abfdf1c4 JE	123	const struct stp_header *sp;
abfdf1c4 JE	124	struct stp_header _stph;
402f9030	125	const u8 header[6] = {0x42, 0x42, 0x03, 0x00, 0x00, 0x00};
1da177e4 LT	126
	127	sp = skb_header_pointer(skb, 0, sizeof(_stph), &_stph);
	128	if (sp == NULL)
8cc784ee	129	return false;
1da177e4 LT	130
	131	/* The stp code only considers these */
	132	if (memcmp(sp, header, sizeof(header)))
8cc784ee	133	return false;
1da177e4	134
c37a2dfa JP	135	if ((info->bitmask & EBT_STP_TYPE) &&
c37a2dfa JP	136	NF_INVF(info, EBT_STP_TYPE, info->type != sp->type))
8cc784ee	137	return false;
1da177e4 LT	138
	139	if (sp->type == BPDU_TYPE_CONFIG &&
	140	info->bitmask & EBT_STP_CONFIG_MASK) {
abfdf1c4 JE	141	const struct stp_config_pdu *st;
abfdf1c4 JE	142	struct stp_config_pdu _stpc;
1da177e4 LT	143
	144	st = skb_header_pointer(skb, sizeof(_stph),
	145	sizeof(_stpc), &_stpc);
	146	if (st == NULL)
8cc784ee	147	return false;
1da177e4 LT	148	return ebt_filter_config(info, st);
1da177e4 LT	149	}
8cc784ee	150	return true;
1da177e4 LT	151	}
1da177e4 LT	152
b0f38452	153	static int ebt_stp_mt_check(const struct xt_mtchk_param *par)
1da177e4	154	{
9b4fce7a	155	const struct ebt_stp_info *info = par->matchinfo;
402f9030 TH	156	const u8 bridge_ula[6] = {0x01, 0x80, 0xc2, 0x00, 0x00, 0x00};
402f9030 TH	157	const u8 msk[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
9b4fce7a	158	const struct ebt_entry *e = par->entryinfo;
1da177e4 LT	159
	160	if (info->bitmask & ~EBT_STP_MASK \|\| info->invflags & ~EBT_STP_MASK \|\|
	161	!(info->bitmask & EBT_STP_MASK))
bd414ee6	162	return -EINVAL;
1da177e4	163	/* Make sure the match only receives stp frames */
55917a21 PNA	164	if (!par->nft_compat &&
	165	(!ether_addr_equal(e->destmac, bridge_ula) \|\|
	166	!ether_addr_equal(e->destmsk, msk) \|\|
	167	!(e->bitmask & EBT_DESTMAC)))
bd414ee6	168	return -EINVAL;
1da177e4	169
bd414ee6	170	return 0;
1da177e4 LT	171	}
1da177e4 LT	172
043ef46c JE	173	static struct xt_match ebt_stp_mt_reg __read_mostly = {
043ef46c JE	174	.name = "stp",
001a18d3 JE	175	.revision = 0,
001a18d3 JE	176	.family = NFPROTO_BRIDGE,
2d06d4a5 JE	177	.match = ebt_stp_mt,
2d06d4a5 JE	178	.checkentry = ebt_stp_mt_check,
fc0e3df4	179	.matchsize = sizeof(struct ebt_stp_info),
1da177e4 LT	180	.me = THIS_MODULE,
	181	};
	182
65b4b4e8	183	static int __init ebt_stp_init(void)
1da177e4	184	{
043ef46c	185	return xt_register_match(&ebt_stp_mt_reg);
1da177e4 LT	186	}
1da177e4 LT	187
65b4b4e8	188	static void __exit ebt_stp_fini(void)
1da177e4	189	{
043ef46c	190	xt_unregister_match(&ebt_stp_mt_reg);
1da177e4 LT	191	}
1da177e4 LT	192
65b4b4e8 AM	193	module_init(ebt_stp_init);
65b4b4e8 AM	194	module_exit(ebt_stp_fini);
f776c4cd	195	MODULE_DESCRIPTION("Ebtables: Spanning Tree Protocol packet match");
1da177e4	196	MODULE_LICENSE("GPL");