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(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(&pkttype_mt_reg); 53 } 54 55 static void __exit pkttype_mt_exit(void) 56 { 57 xt_unregister_match(&pkttype_mt_reg); 58 } 59 60 module_init(pkttype_mt_init); 61 module_exit(pkttype_mt_exit); 62