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, xt_hooknum(par)); 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 44 return nf_ct_netns_get(par->net, par->family); 45 } 46 47 static void redirect_tg_destroy(const struct xt_tgdtor_param *par) 48 { 49 nf_ct_netns_put(par->net, par->family); 50 } 51 52 /* FIXME: Take multiple ranges --RR */ 53 static int redirect_tg4_check(const struct xt_tgchk_param *par) 54 { 55 const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo; 56 57 if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) { 58 pr_debug("bad MAP_IPS.\n"); 59 return -EINVAL; 60 } 61 if (mr->rangesize != 1) { 62 pr_debug("bad rangesize %u.\n", mr->rangesize); 63 return -EINVAL; 64 } 65 return nf_ct_netns_get(par->net, par->family); 66 } 67 68 static unsigned int 69 redirect_tg4(struct sk_buff *skb, const struct xt_action_param *par) 70 { 71 return nf_nat_redirect_ipv4(skb, par->targinfo, xt_hooknum(par)); 72 } 73 74 static struct xt_target redirect_tg_reg[] __read_mostly = { 75 { 76 .name = "REDIRECT", 77 .family = NFPROTO_IPV6, 78 .revision = 0, 79 .table = "nat", 80 .checkentry = redirect_tg6_checkentry, 81 .destroy = redirect_tg_destroy, 82 .target = redirect_tg6, 83 .targetsize = sizeof(struct nf_nat_range), 84 .hooks = (1 << NF_INET_PRE_ROUTING) | 85 (1 << NF_INET_LOCAL_OUT), 86 .me = THIS_MODULE, 87 }, 88 { 89 .name = "REDIRECT", 90 .family = NFPROTO_IPV4, 91 .revision = 0, 92 .table = "nat", 93 .target = redirect_tg4, 94 .checkentry = redirect_tg4_check, 95 .destroy = redirect_tg_destroy, 96 .targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat), 97 .hooks = (1 << NF_INET_PRE_ROUTING) | 98 (1 << NF_INET_LOCAL_OUT), 99 .me = THIS_MODULE, 100 }, 101 }; 102 103 static int __init redirect_tg_init(void) 104 { 105 return xt_register_targets(redirect_tg_reg, 106 ARRAY_SIZE(redirect_tg_reg)); 107 } 108 109 static void __exit redirect_tg_exit(void) 110 { 111 xt_unregister_targets(redirect_tg_reg, ARRAY_SIZE(redirect_tg_reg)); 112 } 113 114 module_init(redirect_tg_init); 115 module_exit(redirect_tg_exit); 116 117 MODULE_LICENSE("GPL"); 118 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); 119 MODULE_DESCRIPTION("Xtables: Connection redirection to localhost"); 120 MODULE_ALIAS("ip6t_REDIRECT"); 121 MODULE_ALIAS("ipt_REDIRECT"); 122