Release 4.11 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;
}

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Bart De Schuymer
403
81.25%
1
16.67%
Joe Perches
75
15.12%
2
33.33%
Jan Engelhardt
16
3.23%
2
33.33%
Tobin C Harding
2
0.40%
1
16.67%
Total
496
100.00%
6
100.00%


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;
}

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CommitProp
Bart De Schuymer
127
64.80%
1
11.11%
David S. Miller
37
18.88%
1
11.11%
Jan Engelhardt
24
12.24%
5
55.56%
Joe Perches
7
3.57%
1
11.11%
Tobin C Harding
1
0.51%
1
11.11%
Total
196
100.00%
9
100.00%



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;
}

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CommitProp
Bart De Schuymer
111
74.50%
1
11.11%
Jan Engelhardt
25
16.78%
5
55.56%
Pablo Neira Ayuso
7
4.70%
1
11.11%
Joe Perches
4
2.68%
1
11.11%
Tobin C Harding
2
1.34%
1
11.11%
Total
149
100.00%
9
100.00%


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);
}

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CommitProp
Bart De Schuymer
13
81.25%
1
33.33%
Jan Engelhardt
2
12.50%
1
33.33%
Andrew Morton
1
6.25%
1
33.33%
Total
16
100.00%
3
100.00%



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

Contributors
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Tokens
Prop
Commits
CommitProp
Bart De Schuymer
12
80.00%
1
33.33%
Jan Engelhardt
2
13.33%
1
33.33%
Andrew Morton
1
6.67%
1
33.33%
Total
15
100.00%
3
100.00%


module_init(ebt_stp_init);

module_exit(ebt_stp_fini);
MODULE_DESCRIPTION("Ebtables: Spanning Tree Protocol packet match");
MODULE_LICENSE("GPL");
Overall Contributors
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Tokens
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Commits
CommitProp
Bart De Schuymer
793
75.09%
1
4.55%
Jan Engelhardt
107
10.13%
13
59.09%
Joe Perches
86
8.14%
3
13.64%
David S. Miller
39
3.69%
2
9.09%
Tobin C Harding
20
1.89%
1
4.55%
Pablo Neira Ayuso
7
0.66%
1
4.55%
Andrew Morton
4
0.38%
1
4.55%
Total
1056
100.00%
22
100.00%
Directory: net/bridge/netfilter

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