1// SPDX-License-Identifier: GPL-2.0-only
2/* (C) 1999-2001 Michal Ludvig <michal@logix.cz>
3 */
4
5#include <linux/module.h>
6#include <linux/skbuff.h>
7#include <linux/if_ether.h>
8#include <linux/if_packet.h>
9#include <linux/in.h>
10#include <linux/ip.h>
11#include <linux/ipv6.h>
12
13#include <linux/netfilter/xt_pkttype.h>
14#include <linux/netfilter/x_tables.h>
15
16MODULE_LICENSE("GPL");
17MODULE_AUTHOR("Michal Ludvig <michal@logix.cz>");
18MODULE_DESCRIPTION("Xtables: link layer packet type match");
19MODULE_ALIAS("ipt_pkttype");
20MODULE_ALIAS("ip6t_pkttype");
21
22static bool
23pkttype_mt(const struct sk_buff *skb, struct xt_action_param *par)
24{
25	const struct xt_pkttype_info *info = par->matchinfo;
26	u_int8_t type;
27
28	if (skb->pkt_type != PACKET_LOOPBACK)
29		type = skb->pkt_type;
30	else if (xt_family(par) == NFPROTO_IPV4 &&
31	    ipv4_is_multicast(ip_hdr(skb)->daddr))
32		type = PACKET_MULTICAST;
33	else if (xt_family(par) == NFPROTO_IPV6)
34		type = PACKET_MULTICAST;
35	else
36		type = PACKET_BROADCAST;
37
38	return (type == info->pkttype) ^ info->invert;
39}
40
41static struct xt_match pkttype_mt_reg __read_mostly = {
42	.name      = "pkttype",
43	.revision  = 0,
44	.family    = NFPROTO_UNSPEC,
45	.match     = pkttype_mt,
46	.matchsize = sizeof(struct xt_pkttype_info),
47	.me        = THIS_MODULE,
48};
49
50static int __init pkttype_mt_init(void)
51{
52	return xt_register_match(&pkttype_mt_reg);
53}
54
55static void __exit pkttype_mt_exit(void)
56{
57	xt_unregister_match(&pkttype_mt_reg);
58}
59
60module_init(pkttype_mt_init);
61module_exit(pkttype_mt_exit);
62