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, const struct xt_match_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->match->family == NFPROTO_IPV4 && 34 ipv4_is_multicast(ip_hdr(skb)->daddr)) 35 type = PACKET_MULTICAST; 36 else if (par->match->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 { 47 .name = "pkttype", 48 .family = NFPROTO_IPV4, 49 .match = pkttype_mt, 50 .matchsize = sizeof(struct xt_pkttype_info), 51 .me = THIS_MODULE, 52 }, 53 { 54 .name = "pkttype", 55 .family = NFPROTO_IPV6, 56 .match = pkttype_mt, 57 .matchsize = sizeof(struct xt_pkttype_info), 58 .me = THIS_MODULE, 59 }, 60 }; 61 62 static int __init pkttype_mt_init(void) 63 { 64 return xt_register_matches(pkttype_mt_reg, ARRAY_SIZE(pkttype_mt_reg)); 65 } 66 67 static void __exit pkttype_mt_exit(void) 68 { 69 xt_unregister_matches(pkttype_mt_reg, ARRAY_SIZE(pkttype_mt_reg)); 70 } 71 72 module_init(pkttype_mt_init); 73 module_exit(pkttype_mt_exit); 74