| 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 | |
| 15 | #include <linux/netfilter/xt_pkttype.h> |
| 16 | #include <linux/netfilter/x_tables.h> |
| 17 | |
| 18 | MODULE_LICENSE("GPL"); |
| 19 | MODULE_AUTHOR("Michal Ludvig <michal@logix.cz>"); |
| 20 | MODULE_DESCRIPTION("IP tables match to match on linklayer packet type"); |
| 21 | MODULE_ALIAS("ipt_pkttype"); |
| 22 | MODULE_ALIAS("ip6t_pkttype"); |
| 23 | |
| 24 | static int match(const struct sk_buff *skb, |
| 25 | const struct net_device *in, |
| 26 | const struct net_device *out, |
| 27 | const struct xt_match *match, |
| 28 | const void *matchinfo, |
| 29 | int offset, |
| 30 | unsigned int protoff, |
| 31 | int *hotdrop) |
| 32 | { |
| 33 | u_int8_t type; |
| 34 | const struct xt_pkttype_info *info = matchinfo; |
| 35 | |
| 36 | if (skb->pkt_type == PACKET_LOOPBACK) |
| 37 | type = (MULTICAST(skb->nh.iph->daddr) |
| 38 | ? PACKET_MULTICAST |
| 39 | : PACKET_BROADCAST); |
| 40 | else |
| 41 | type = skb->pkt_type; |
| 42 | |
| 43 | return (type == info->pkttype) ^ info->invert; |
| 44 | } |
| 45 | |
| 46 | static struct xt_match xt_pkttype_match[] = { |
| 47 | { |
| 48 | .name = "pkttype", |
| 49 | .family = AF_INET, |
| 50 | .match = match, |
| 51 | .matchsize = sizeof(struct xt_pkttype_info), |
| 52 | .me = THIS_MODULE, |
| 53 | }, |
| 54 | { |
| 55 | .name = "pkttype", |
| 56 | .family = AF_INET6, |
| 57 | .match = match, |
| 58 | .matchsize = sizeof(struct xt_pkttype_info), |
| 59 | .me = THIS_MODULE, |
| 60 | }, |
| 61 | }; |
| 62 | |
| 63 | static int __init xt_pkttype_init(void) |
| 64 | { |
| 65 | return xt_register_matches(xt_pkttype_match, |
| 66 | ARRAY_SIZE(xt_pkttype_match)); |
| 67 | } |
| 68 | |
| 69 | static void __exit xt_pkttype_fini(void) |
| 70 | { |
| 71 | xt_unregister_matches(xt_pkttype_match, ARRAY_SIZE(xt_pkttype_match)); |
| 72 | } |
| 73 | |
| 74 | module_init(xt_pkttype_init); |
| 75 | module_exit(xt_pkttype_fini); |