| 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 | |
| 16 | MODULE_LICENSE("GPL"); |
| 17 | MODULE_AUTHOR("Michal Ludvig <michal@logix.cz>"); |
| 18 | MODULE_DESCRIPTION("Xtables: link layer packet type match"); |
| 19 | MODULE_ALIAS("ipt_pkttype"); |
| 20 | MODULE_ALIAS("ip6t_pkttype"); |
| 21 | |
| 22 | static bool |
| 23 | pkttype_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(addr: 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 | |
| 41 | static 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 | |
| 50 | static int __init pkttype_mt_init(void) |
| 51 | { |
| 52 | return xt_register_match(target: &pkttype_mt_reg); |
| 53 | } |
| 54 | |
| 55 | static void __exit pkttype_mt_exit(void) |
| 56 | { |
| 57 | xt_unregister_match(target: &pkttype_mt_reg); |
| 58 | } |
| 59 | |
| 60 | module_init(pkttype_mt_init); |
| 61 | module_exit(pkttype_mt_exit); |
| 62 |