| 1 | /* (C) 1999-2001 Michal Ludvig <michal@logix.cz> |
| 2 | * |
| 3 | * This program is free software; you can redistribute it and/or modify |
| 4 | * it under the terms of the GNU General Public License version 2 as |
| 5 | * published by the Free Software Foundation. |
| 6 | */ |
| 7 | |
| 8 | #include <linux/module.h> |
| 9 | #include <linux/skbuff.h> |
| 10 | #include <linux/if_ether.h> |
| 11 | #include <linux/if_packet.h> |
| 12 | #include <linux/in.h> |
| 13 | #include <linux/ip.h> |
| 14 | #include <linux/ipv6.h> |
| 15 | |
| 16 | #include <linux/netfilter/xt_pkttype.h> |
| 17 | #include <linux/netfilter/x_tables.h> |
| 18 | |
| 19 | MODULE_LICENSE("GPL"); |
| 20 | MODULE_AUTHOR("Michal Ludvig <michal@logix.cz>"); |
| 21 | MODULE_DESCRIPTION("Xtables: link layer packet type match"); |
| 22 | MODULE_ALIAS("ipt_pkttype"); |
| 23 | MODULE_ALIAS("ip6t_pkttype"); |
| 24 | |
| 25 | static bool |
| 26 | pkttype_mt(const struct sk_buff *skb, struct xt_action_param *par) |
| 27 | { |
| 28 | const struct xt_pkttype_info *info = par->matchinfo; |
| 29 | u_int8_t type; |
| 30 | |
| 31 | if (skb->pkt_type != PACKET_LOOPBACK) |
| 32 | type = skb->pkt_type; |
| 33 | else if (par->family == NFPROTO_IPV4 && |
| 34 | ipv4_is_multicast(ip_hdr(skb)->daddr)) |
| 35 | type = PACKET_MULTICAST; |
| 36 | else if (par->family == NFPROTO_IPV6 && |
| 37 | ipv6_hdr(skb)->daddr.s6_addr[0] == 0xFF) |
| 38 | type = PACKET_MULTICAST; |
| 39 | else |
| 40 | type = PACKET_BROADCAST; |
| 41 | |
| 42 | return (type == info->pkttype) ^ info->invert; |
| 43 | } |
| 44 | |
| 45 | static struct xt_match pkttype_mt_reg __read_mostly = { |
| 46 | .name = "pkttype", |
| 47 | .revision = 0, |
| 48 | .family = NFPROTO_UNSPEC, |
| 49 | .match = pkttype_mt, |
| 50 | .matchsize = sizeof(struct xt_pkttype_info), |
| 51 | .me = THIS_MODULE, |
| 52 | }; |
| 53 | |
| 54 | static int __init pkttype_mt_init(void) |
| 55 | { |
| 56 | return xt_register_match(&pkttype_mt_reg); |
| 57 | } |
| 58 | |
| 59 | static void __exit pkttype_mt_exit(void) |
| 60 | { |
| 61 | xt_unregister_match(&pkttype_mt_reg); |
| 62 | } |
| 63 | |
| 64 | module_init(pkttype_mt_init); |
| 65 | module_exit(pkttype_mt_exit); |