1 /* 2 * (C) 1999-2001 Paul `Rusty' Russell 3 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> 4 * Copyright (c) 2011 Patrick McHardy <kaber@trash.net> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * Based on Rusty Russell's IPv4 REDIRECT target. Development of IPv6 11 * NAT funded by Astaro. 12 */ 13 14 #include <linux/if.h> 15 #include <linux/inetdevice.h> 16 #include <linux/ip.h> 17 #include <linux/kernel.h> 18 #include <linux/module.h> 19 #include <linux/netdevice.h> 20 #include <linux/netfilter.h> 21 #include <linux/types.h> 22 #include <linux/netfilter_ipv4.h> 23 #include <linux/netfilter_ipv6.h> 24 #include <linux/netfilter/x_tables.h> 25 #include <net/addrconf.h> 26 #include <net/checksum.h> 27 #include <net/protocol.h> 28 #include <net/netfilter/nf_nat.h> 29 #include <net/netfilter/nf_nat_redirect.h> 30 31 static unsigned int 32 redirect_tg6(struct sk_buff *skb, const struct xt_action_param *par) 33 { 34 return nf_nat_redirect_ipv6(skb, par->targinfo, par->hooknum); 35 } 36 37 static int redirect_tg6_checkentry(const struct xt_tgchk_param *par) 38 { 39 const struct nf_nat_range *range = par->targinfo; 40 41 if (range->flags & NF_NAT_RANGE_MAP_IPS) 42 return -EINVAL; 43 return 0; 44 } 45 46 /* FIXME: Take multiple ranges --RR */ 47 static int redirect_tg4_check(const struct xt_tgchk_param *par) 48 { 49 const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo; 50 51 if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) { 52 pr_debug("bad MAP_IPS.\n"); 53 return -EINVAL; 54 } 55 if (mr->rangesize != 1) { 56 pr_debug("bad rangesize %u.\n", mr->rangesize); 57 return -EINVAL; 58 } 59 return 0; 60 } 61 62 static unsigned int 63 redirect_tg4(struct sk_buff *skb, const struct xt_action_param *par) 64 { 65 return nf_nat_redirect_ipv4(skb, par->targinfo, par->hooknum); 66 } 67 68 static struct xt_target redirect_tg_reg[] __read_mostly = { 69 { 70 .name = "REDIRECT", 71 .family = NFPROTO_IPV6, 72 .revision = 0, 73 .table = "nat", 74 .checkentry = redirect_tg6_checkentry, 75 .target = redirect_tg6, 76 .targetsize = sizeof(struct nf_nat_range), 77 .hooks = (1 << NF_INET_PRE_ROUTING) | 78 (1 << NF_INET_LOCAL_OUT), 79 .me = THIS_MODULE, 80 }, 81 { 82 .name = "REDIRECT", 83 .family = NFPROTO_IPV4, 84 .revision = 0, 85 .table = "nat", 86 .target = redirect_tg4, 87 .checkentry = redirect_tg4_check, 88 .targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat), 89 .hooks = (1 << NF_INET_PRE_ROUTING) | 90 (1 << NF_INET_LOCAL_OUT), 91 .me = THIS_MODULE, 92 }, 93 }; 94 95 static int __init redirect_tg_init(void) 96 { 97 return xt_register_targets(redirect_tg_reg, 98 ARRAY_SIZE(redirect_tg_reg)); 99 } 100 101 static void __exit redirect_tg_exit(void) 102 { 103 xt_unregister_targets(redirect_tg_reg, ARRAY_SIZE(redirect_tg_reg)); 104 } 105 106 module_init(redirect_tg_init); 107 module_exit(redirect_tg_exit); 108 109 MODULE_LICENSE("GPL"); 110 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); 111 MODULE_DESCRIPTION("Xtables: Connection redirection to localhost"); 112 MODULE_ALIAS("ip6t_REDIRECT"); 113 MODULE_ALIAS("ipt_REDIRECT"); 114