[mirror_ubuntu-hirsute-kernel.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/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_stp.h>
#include <linux/etherdevice.h>
#include <linux/module.h>

#define BPDU_TYPE_CONFIG 0
#define BPDU_TYPE_TCN 0x80

struct stp_header {
	uint8_t dsap;
	uint8_t ssap;
	uint8_t ctrl;
	uint8_t pid;
	uint8_t vers;
	uint8_t type;
};

struct stp_config_pdu {
	uint8_t flags;
	uint8_t root[8];
	uint8_t root_cost[4];
	uint8_t sender[8];
	uint8_t port[2];
	uint8_t msg_age[2];
	uint8_t max_age[2];
	uint8_t hello_time[2];
	uint8_t 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 int ebt_filter_config(struct ebt_stp_info *info,
   struct stp_config_pdu *stpc)
{
	struct ebt_stp_config_info *c;
	uint16_t v16;
	uint32_t v32;
	int verdict, i;

	c = &info->config;
	if ((info->bitmask & EBT_STP_FLAGS) &&
	    FWINV(c->flags != stpc->flags, EBT_STP_FLAGS))
		return EBT_NOMATCH;
	if (info->bitmask & EBT_STP_ROOTPRIO) {
		v16 = NR16(stpc->root);
		if (FWINV(v16 < c->root_priol ||
		    v16 > c->root_priou, EBT_STP_ROOTPRIO))
			return EBT_NOMATCH;
	}
	if (info->bitmask & EBT_STP_ROOTADDR) {
		verdict = 0;
		for (i = 0; i < 6; i++)
			verdict |= (stpc->root[2+i] ^ c->root_addr[i]) &
			           c->root_addrmsk[i];
		if (FWINV(verdict != 0, EBT_STP_ROOTADDR))
			return EBT_NOMATCH;
	}
	if (info->bitmask & EBT_STP_ROOTCOST) {
		v32 = NR32(stpc->root_cost);
		if (FWINV(v32 < c->root_costl ||
		    v32 > c->root_costu, EBT_STP_ROOTCOST))
			return EBT_NOMATCH;
	}
	if (info->bitmask & EBT_STP_SENDERPRIO) {
		v16 = NR16(stpc->sender);
		if (FWINV(v16 < c->sender_priol ||
		    v16 > c->sender_priou, EBT_STP_SENDERPRIO))
			return EBT_NOMATCH;
	}
	if (info->bitmask & EBT_STP_SENDERADDR) {
		verdict = 0;
		for (i = 0; i < 6; i++)
			verdict |= (stpc->sender[2+i] ^ c->sender_addr[i]) &
			           c->sender_addrmsk[i];
		if (FWINV(verdict != 0, EBT_STP_SENDERADDR))
			return EBT_NOMATCH;
	}
	if (info->bitmask & EBT_STP_PORT) {
		v16 = NR16(stpc->port);
		if (FWINV(v16 < c->portl ||
		    v16 > c->portu, EBT_STP_PORT))
			return EBT_NOMATCH;
	}
	if (info->bitmask & EBT_STP_MSGAGE) {
		v16 = NR16(stpc->msg_age);
		if (FWINV(v16 < c->msg_agel ||
		    v16 > c->msg_ageu, EBT_STP_MSGAGE))
			return EBT_NOMATCH;
	}
	if (info->bitmask & EBT_STP_MAXAGE) {
		v16 = NR16(stpc->max_age);
		if (FWINV(v16 < c->max_agel ||
		    v16 > c->max_ageu, EBT_STP_MAXAGE))
			return EBT_NOMATCH;
	}
	if (info->bitmask & EBT_STP_HELLOTIME) {
		v16 = NR16(stpc->hello_time);
		if (FWINV(v16 < c->hello_timel ||
		    v16 > c->hello_timeu, EBT_STP_HELLOTIME))
			return EBT_NOMATCH;
	}
	if (info->bitmask & EBT_STP_FWDD) {
		v16 = NR16(stpc->forward_delay);
		if (FWINV(v16 < c->forward_delayl ||
		    v16 > c->forward_delayu, EBT_STP_FWDD))
			return EBT_NOMATCH;
	}
	return EBT_MATCH;
}

static int ebt_filter_stp(const struct sk_buff *skb, const struct net_device *in,
   const struct net_device *out, const void *data, unsigned int datalen)
{
	struct ebt_stp_info *info = (struct ebt_stp_info *)data;
	struct stp_header _stph, *sp;
	uint8_t header[6] = {0x42, 0x42, 0x03, 0x00, 0x00, 0x00};

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

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

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

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

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

static int ebt_stp_check(const char *tablename, unsigned int hookmask,
   const struct ebt_entry *e, void *data, unsigned int datalen)
{
	struct ebt_stp_info *info = (struct ebt_stp_info *)data;
	int len = EBT_ALIGN(sizeof(struct ebt_stp_info));
	uint8_t bridge_ula[6] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
	uint8_t msk[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };

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

	return 0;
}

static struct ebt_match filter_stp =
{
	.name		= EBT_STP_MATCH,
	.match		= ebt_filter_stp,
	.check		= ebt_stp_check,
	.me		= THIS_MODULE,
};

static int __init ebt_stp_init(void)
{
	return ebt_register_match(&filter_stp);
}

static void __exit ebt_stp_fini(void)
{
	ebt_unregister_match(&filter_stp);
}

module_init(ebt_stp_init);
module_exit(ebt_stp_fini);
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	*/
	10
	11	#include <linux/netfilter_bridge/ebtables.h>
	12	#include <linux/netfilter_bridge/ebt_stp.h>
82bf7e97	13	#include <linux/etherdevice.h>
1da177e4 LT	14	#include <linux/module.h>
	15
	16	#define BPDU_TYPE_CONFIG 0
	17	#define BPDU_TYPE_TCN 0x80
	18
	19	struct stp_header {
	20	uint8_t dsap;
	21	uint8_t ssap;
	22	uint8_t ctrl;
	23	uint8_t pid;
	24	uint8_t vers;
	25	uint8_t type;
	26	};
	27
	28	struct stp_config_pdu {
	29	uint8_t flags;
	30	uint8_t root[8];
	31	uint8_t root_cost[4];
	32	uint8_t sender[8];
	33	uint8_t port[2];
	34	uint8_t msg_age[2];
	35	uint8_t max_age[2];
	36	uint8_t hello_time[2];
	37	uint8_t forward_delay[2];
	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
	43	static int ebt_filter_config(struct ebt_stp_info *info,
	44	struct stp_config_pdu *stpc)
	45	{
	46	struct ebt_stp_config_info *c;
	47	uint16_t v16;
	48	uint32_t v32;
	49	int verdict, i;
	50
	51	c = &info->config;
	52	if ((info->bitmask & EBT_STP_FLAGS) &&
	53	FWINV(c->flags != stpc->flags, EBT_STP_FLAGS))
	54	return EBT_NOMATCH;
	55	if (info->bitmask & EBT_STP_ROOTPRIO) {
	56	v16 = NR16(stpc->root);
	57	if (FWINV(v16 < c->root_priol \|\|
	58	v16 > c->root_priou, EBT_STP_ROOTPRIO))
	59	return EBT_NOMATCH;
	60	}
	61	if (info->bitmask & EBT_STP_ROOTADDR) {
	62	verdict = 0;
	63	for (i = 0; i < 6; i++)
	64	verdict \|= (stpc->root[2+i] ^ c->root_addr[i]) &
	65	c->root_addrmsk[i];
	66	if (FWINV(verdict != 0, EBT_STP_ROOTADDR))
	67	return EBT_NOMATCH;
	68	}
	69	if (info->bitmask & EBT_STP_ROOTCOST) {
	70	v32 = NR32(stpc->root_cost);
	71	if (FWINV(v32 < c->root_costl \|\|
	72	v32 > c->root_costu, EBT_STP_ROOTCOST))
	73	return EBT_NOMATCH;
	74	}
	75	if (info->bitmask & EBT_STP_SENDERPRIO) {
	76	v16 = NR16(stpc->sender);
	77	if (FWINV(v16 < c->sender_priol \|\|
78	v16 > c->sender_priou, EBT_STP_SENDERPRIO))
79	return EBT_NOMATCH;
80	}
81	if (info->bitmask & EBT_STP_SENDERADDR) {
82	verdict = 0;
83	for (i = 0; i < 6; i++)
84	verdict \|= (stpc->sender[2+i] ^ c->sender_addr[i]) &
85	c->sender_addrmsk[i];
86	if (FWINV(verdict != 0, EBT_STP_SENDERADDR))
87	return EBT_NOMATCH;
88	}
89	if (info->bitmask & EBT_STP_PORT) {
90	v16 = NR16(stpc->port);
91	if (FWINV(v16 < c->portl \|\|
92	v16 > c->portu, EBT_STP_PORT))
93	return EBT_NOMATCH;
94	}
95	if (info->bitmask & EBT_STP_MSGAGE) {
96	v16 = NR16(stpc->msg_age);
97	if (FWINV(v16 < c->msg_agel \|\|
98	v16 > c->msg_ageu, EBT_STP_MSGAGE))
99	return EBT_NOMATCH;
100	}
101	if (info->bitmask & EBT_STP_MAXAGE) {
102	v16 = NR16(stpc->max_age);
103	if (FWINV(v16 < c->max_agel \|\|
104	v16 > c->max_ageu, EBT_STP_MAXAGE))
105	return EBT_NOMATCH;
106	}
107	if (info->bitmask & EBT_STP_HELLOTIME) {
108	v16 = NR16(stpc->hello_time);
109	if (FWINV(v16 < c->hello_timel \|\|
110	v16 > c->hello_timeu, EBT_STP_HELLOTIME))
111	return EBT_NOMATCH;
112	}
113	if (info->bitmask & EBT_STP_FWDD) {
114	v16 = NR16(stpc->forward_delay);
115	if (FWINV(v16 < c->forward_delayl \|\|
116	v16 > c->forward_delayu, EBT_STP_FWDD))
117	return EBT_NOMATCH;
118	}
119	return EBT_MATCH;
120	}
121
122	static int ebt_filter_stp(const struct sk_buff skb, const struct net_device in,
123	const struct net_device out, const void data, unsigned int datalen)
124	{
125	struct ebt_stp_info info = (struct ebt_stp_info )data;
126	struct stp_header _stph, *sp;
127	uint8_t header[6] = {0x42, 0x42, 0x03, 0x00, 0x00, 0x00};
128
129	sp = skb_header_pointer(skb, 0, sizeof(_stph), &_stph);
130	if (sp == NULL)
131	return EBT_NOMATCH;
132
133	/* The stp code only considers these */
134	if (memcmp(sp, header, sizeof(header)))
135	return EBT_NOMATCH;
136
137	if (info->bitmask & EBT_STP_TYPE
138	&& FWINV(info->type != sp->type, EBT_STP_TYPE))
139	return EBT_NOMATCH;
140
141	if (sp->type == BPDU_TYPE_CONFIG &&
142	info->bitmask & EBT_STP_CONFIG_MASK) {
143	struct stp_config_pdu _stpc, *st;
144
145	st = skb_header_pointer(skb, sizeof(_stph),
146	sizeof(_stpc), &_stpc);
147	if (st == NULL)
148	return EBT_NOMATCH;
149	return ebt_filter_config(info, st);
150	}
151	return EBT_MATCH;
152	}
153
154	static int ebt_stp_check(const char *tablename, unsigned int hookmask,
155	const struct ebt_entry e, void data, unsigned int datalen)
156	{
157	struct ebt_stp_info info = (struct ebt_stp_info )data;
158	int len = EBT_ALIGN(sizeof(struct ebt_stp_info));
159	uint8_t bridge_ula[6] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
160	uint8_t msk[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
161
162	if (info->bitmask & ~EBT_STP_MASK \|\| info->invflags & ~EBT_STP_MASK \|\|
163	!(info->bitmask & EBT_STP_MASK))
164	return -EINVAL;
165	if (datalen != len)
166	return -EINVAL;
167	/* Make sure the match only receives stp frames */
d3f4a687 KK	168	if (compare_ether_addr(e->destmac, bridge_ula) \|\|
d3f4a687 KK	169	compare_ether_addr(e->destmsk, msk) \|\| !(e->bitmask & EBT_DESTMAC))
1da177e4 LT	170	return -EINVAL;
	171
	172	return 0;
	173	}
	174
	175	static struct ebt_match filter_stp =
	176	{
	177	.name = EBT_STP_MATCH,
	178	.match = ebt_filter_stp,
	179	.check = ebt_stp_check,
	180	.me = THIS_MODULE,
	181	};
	182
65b4b4e8	183	static int __init ebt_stp_init(void)
1da177e4 LT	184	{
	185	return ebt_register_match(&filter_stp);
	186	}
	187
65b4b4e8	188	static void __exit ebt_stp_fini(void)
1da177e4 LT	189	{
	190	ebt_unregister_match(&filter_stp);
	191	}
	192
65b4b4e8 AM	193	module_init(ebt_stp_init);
65b4b4e8 AM	194	module_exit(ebt_stp_fini);
1da177e4	195	MODULE_LICENSE("GPL");