Release 4.7 net/bridge/netfilter/ebt_arp.c

/*
 *  ebt_arp
 *
 *      Authors:
 *      Bart De Schuymer <bdschuym@pandora.be>
 *      Tim Gardner <timg@tpi.com>
 *
 *  April, 2002
 *
 */
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/module.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_arp.h>


static bool

ebt_arp_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
	const struct ebt_arp_info *info = par->matchinfo;
	const struct arphdr *ah;
	struct arphdr _arph;

	ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph);
	if (ah == NULL)
		return false;
	if (info->bitmask & EBT_ARP_OPCODE && FWINV(info->opcode !=
	   ah->ar_op, EBT_ARP_OPCODE))
		return false;
	if (info->bitmask & EBT_ARP_HTYPE && FWINV(info->htype !=
	   ah->ar_hrd, EBT_ARP_HTYPE))
		return false;
	if (info->bitmask & EBT_ARP_PTYPE && FWINV(info->ptype !=
	   ah->ar_pro, EBT_ARP_PTYPE))
		return false;

	if (info->bitmask & (EBT_ARP_SRC_IP | EBT_ARP_DST_IP | EBT_ARP_GRAT)) {
		const __be32 *sap, *dap;
		__be32 saddr, daddr;

		if (ah->ar_pln != sizeof(__be32) || ah->ar_pro != htons(ETH_P_IP))
			return false;
		sap = skb_header_pointer(skb, sizeof(struct arphdr) +
					ah->ar_hln, sizeof(saddr),
					&saddr);
		if (sap == NULL)
			return false;
		dap = skb_header_pointer(skb, sizeof(struct arphdr) +
					2*ah->ar_hln+sizeof(saddr),
					sizeof(daddr), &daddr);
		if (dap == NULL)
			return false;
		if (info->bitmask & EBT_ARP_SRC_IP &&
		    FWINV(info->saddr != (*sap & info->smsk), EBT_ARP_SRC_IP))
			return false;
		if (info->bitmask & EBT_ARP_DST_IP &&
		    FWINV(info->daddr != (*dap & info->dmsk), EBT_ARP_DST_IP))
			return false;
		if (info->bitmask & EBT_ARP_GRAT &&
		    FWINV(*dap != *sap, EBT_ARP_GRAT))
			return false;
	}

	if (info->bitmask & (EBT_ARP_SRC_MAC | EBT_ARP_DST_MAC)) {
		const unsigned char *mp;
		unsigned char _mac[ETH_ALEN];
		uint8_t verdict, i;

		if (ah->ar_hln != ETH_ALEN || ah->ar_hrd != htons(ARPHRD_ETHER))
			return false;
		if (info->bitmask & EBT_ARP_SRC_MAC) {
			mp = skb_header_pointer(skb, sizeof(struct arphdr),
						sizeof(_mac), &_mac);
			if (mp == NULL)
				return false;
			verdict = 0;
			for (i = 0; i < 6; i++)
				verdict |= (mp[i] ^ info->smaddr[i]) &
				       info->smmsk[i];
			if (FWINV(verdict != 0, EBT_ARP_SRC_MAC))
				return false;
		}

		if (info->bitmask & EBT_ARP_DST_MAC) {
			mp = skb_header_pointer(skb, sizeof(struct arphdr) +
						ah->ar_hln + ah->ar_pln,
						sizeof(_mac), &_mac);
			if (mp == NULL)
				return false;
			verdict = 0;
			for (i = 0; i < 6; i++)
				verdict |= (mp[i] ^ info->dmaddr[i]) &
					info->dmmsk[i];
			if (FWINV(verdict != 0, EBT_ARP_DST_MAC))
				return false;
		}
	}

	return true;
}

Contributors
Person
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bart de schuymer
bart de schuymer
463
78.08%
5
41.67%
david s. miller
david s. miller
87
14.67%
1
8.33%
jan engelhardt
jan engelhardt
41
6.91%
5
41.67%
al viro
al viro
2
0.34%
1
8.33%
Total
593
100.00%
12
100.00%



static int ebt_arp_mt_check(const struct xt_mtchk_param *par)
{
	const struct ebt_arp_info *info = par->matchinfo;
	const struct ebt_entry *e = par->entryinfo;

	if ((e->ethproto != htons(ETH_P_ARP) &&
	   e->ethproto != htons(ETH_P_RARP)) ||
	   e->invflags & EBT_IPROTO)
		return -EINVAL;
	if (info->bitmask & ~EBT_ARP_MASK || info->invflags & ~EBT_ARP_MASK)
		return -EINVAL;
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
bart de schuymer
bart de schuymer
62
71.26%
1
14.29%
jan engelhardt
jan engelhardt
23
26.44%
5
71.43%
arnaldo carvalho de melo
arnaldo carvalho de melo
2
2.30%
1
14.29%
Total
87
100.00%
7
100.00%


static struct xt_match ebt_arp_mt_reg __read_mostly = {
	.name		= "arp",
	.revision	= 0,
	.family		= NFPROTO_BRIDGE,
	.match		= ebt_arp_mt,
	.checkentry	= ebt_arp_mt_check,
	.matchsize	= sizeof(struct ebt_arp_info),
	.me		= THIS_MODULE,
};



static int __init ebt_arp_init(void)
{
	return xt_register_match(&ebt_arp_mt_reg);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
bart de schuymer
bart de schuymer
13
81.25%
1
33.33%
jan engelhardt
jan engelhardt
2
12.50%
1
33.33%
andrew morton
andrew morton
1
6.25%
1
33.33%
Total
16
100.00%
3
100.00%



static void __exit ebt_arp_fini(void)
{
	xt_unregister_match(&ebt_arp_mt_reg);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
bart de schuymer
bart de schuymer
12
80.00%
1
33.33%
jan engelhardt
jan engelhardt
2
13.33%
1
33.33%
andrew morton
andrew morton
1
6.67%
1
33.33%
Total
15
100.00%
3
100.00%


module_init(ebt_arp_init);

module_exit(ebt_arp_fini);
MODULE_DESCRIPTION("Ebtables: ARP protocol packet match");
MODULE_LICENSE("GPL");
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
bart de schuymer
bart de schuymer
595
74.65%
6
26.09%
jan engelhardt
jan engelhardt
107
13.43%
13
56.52%
david s. miller
david s. miller
87
10.92%
1
4.35%
andrew morton
andrew morton
4
0.50%
1
4.35%
arnaldo carvalho de melo
arnaldo carvalho de melo
2
0.25%
1
4.35%
al viro
al viro
2
0.25%
1
4.35%
Total
797
100.00%
23
100.00%
  
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