1 /* 2 * IP6 tables REJECT target module 3 * Linux INET6 implementation 4 * 5 * Copyright (C)2003 USAGI/WIDE Project 6 * 7 * Authors: 8 * Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp> 9 * 10 * Copyright (c) 2005-2007 Patrick McHardy <kaber@trash.net> 11 * 12 * Based on net/ipv4/netfilter/ipt_REJECT.c 13 * 14 * This program is free software; you can redistribute it and/or 15 * modify it under the terms of the GNU General Public License 16 * as published by the Free Software Foundation; either version 17 * 2 of the License, or (at your option) any later version. 18 */ 19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 20 21 #include <linux/gfp.h> 22 #include <linux/module.h> 23 #include <linux/skbuff.h> 24 #include <linux/icmpv6.h> 25 #include <linux/netdevice.h> 26 #include <net/icmp.h> 27 #include <net/flow.h> 28 #include <linux/netfilter/x_tables.h> 29 #include <linux/netfilter_ipv6/ip6_tables.h> 30 #include <linux/netfilter_ipv6/ip6t_REJECT.h> 31 32 #include <net/netfilter/ipv6/nf_reject.h> 33 34 MODULE_AUTHOR("Yasuyuki KOZAKAI <yasuyuki.kozakai@toshiba.co.jp>"); 35 MODULE_DESCRIPTION("Xtables: packet \"rejection\" target for IPv6"); 36 MODULE_LICENSE("GPL"); 37 38 static unsigned int 39 reject_tg6(struct sk_buff *skb, const struct xt_action_param *par) 40 { 41 const struct ip6t_reject_info *reject = par->targinfo; 42 struct net *net = xt_net(par); 43 44 switch (reject->with) { 45 case IP6T_ICMP6_NO_ROUTE: 46 nf_send_unreach6(net, skb, ICMPV6_NOROUTE, xt_hooknum(par)); 47 break; 48 case IP6T_ICMP6_ADM_PROHIBITED: 49 nf_send_unreach6(net, skb, ICMPV6_ADM_PROHIBITED, 50 xt_hooknum(par)); 51 break; 52 case IP6T_ICMP6_NOT_NEIGHBOUR: 53 nf_send_unreach6(net, skb, ICMPV6_NOT_NEIGHBOUR, 54 xt_hooknum(par)); 55 break; 56 case IP6T_ICMP6_ADDR_UNREACH: 57 nf_send_unreach6(net, skb, ICMPV6_ADDR_UNREACH, 58 xt_hooknum(par)); 59 break; 60 case IP6T_ICMP6_PORT_UNREACH: 61 nf_send_unreach6(net, skb, ICMPV6_PORT_UNREACH, 62 xt_hooknum(par)); 63 break; 64 case IP6T_ICMP6_ECHOREPLY: 65 /* Do nothing */ 66 break; 67 case IP6T_TCP_RESET: 68 nf_send_reset6(net, skb, xt_hooknum(par)); 69 break; 70 case IP6T_ICMP6_POLICY_FAIL: 71 nf_send_unreach6(net, skb, ICMPV6_POLICY_FAIL, xt_hooknum(par)); 72 break; 73 case IP6T_ICMP6_REJECT_ROUTE: 74 nf_send_unreach6(net, skb, ICMPV6_REJECT_ROUTE, 75 xt_hooknum(par)); 76 break; 77 } 78 79 return NF_DROP; 80 } 81 82 static int reject_tg6_check(const struct xt_tgchk_param *par) 83 { 84 const struct ip6t_reject_info *rejinfo = par->targinfo; 85 const struct ip6t_entry *e = par->entryinfo; 86 87 if (rejinfo->with == IP6T_ICMP6_ECHOREPLY) { 88 pr_info_ratelimited("ECHOREPLY is not supported\n"); 89 return -EINVAL; 90 } else if (rejinfo->with == IP6T_TCP_RESET) { 91 /* Must specify that it's a TCP packet */ 92 if (!(e->ipv6.flags & IP6T_F_PROTO) || 93 e->ipv6.proto != IPPROTO_TCP || 94 (e->ipv6.invflags & XT_INV_PROTO)) { 95 pr_info_ratelimited("TCP_RESET illegal for non-tcp\n"); 96 return -EINVAL; 97 } 98 } 99 return 0; 100 } 101 102 static struct xt_target reject_tg6_reg __read_mostly = { 103 .name = "REJECT", 104 .family = NFPROTO_IPV6, 105 .target = reject_tg6, 106 .targetsize = sizeof(struct ip6t_reject_info), 107 .table = "filter", 108 .hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD) | 109 (1 << NF_INET_LOCAL_OUT), 110 .checkentry = reject_tg6_check, 111 .me = THIS_MODULE 112 }; 113 114 static int __init reject_tg6_init(void) 115 { 116 return xt_register_target(&reject_tg6_reg); 117 } 118 119 static void __exit reject_tg6_exit(void) 120 { 121 xt_unregister_target(&reject_tg6_reg); 122 } 123 124 module_init(reject_tg6_init); 125 module_exit(reject_tg6_exit); 126