Arturo Borrero | 8b13edd | 2014-10-16 12:23:29 +0200 | [diff] [blame] | 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> |
Pablo Neira Ayuso | b59eaf9 | 2014-11-26 12:46:50 +0100 | [diff] [blame] | 23 | #include <linux/netfilter_ipv6.h> |
Arturo Borrero | 8b13edd | 2014-10-16 12:23:29 +0200 | [diff] [blame] | 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> |
Pablo Neira Ayuso | b59eaf9 | 2014-11-26 12:46:50 +0100 | [diff] [blame] | 29 | #include <net/netfilter/nf_nat_redirect.h> |
Arturo Borrero | 8b13edd | 2014-10-16 12:23:29 +0200 | [diff] [blame] | 30 | |
| 31 | unsigned int |
| 32 | nf_nat_redirect_ipv4(struct sk_buff *skb, |
| 33 | const struct nf_nat_ipv4_multi_range_compat *mr, |
| 34 | unsigned int hooknum) |
| 35 | { |
| 36 | struct nf_conn *ct; |
| 37 | enum ip_conntrack_info ctinfo; |
| 38 | __be32 newdst; |
| 39 | struct nf_nat_range newrange; |
| 40 | |
| 41 | NF_CT_ASSERT(hooknum == NF_INET_PRE_ROUTING || |
| 42 | hooknum == NF_INET_LOCAL_OUT); |
| 43 | |
| 44 | ct = nf_ct_get(skb, &ctinfo); |
| 45 | NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED)); |
| 46 | |
| 47 | /* Local packets: make them go to loopback */ |
| 48 | if (hooknum == NF_INET_LOCAL_OUT) { |
| 49 | newdst = htonl(0x7F000001); |
| 50 | } else { |
| 51 | struct in_device *indev; |
| 52 | struct in_ifaddr *ifa; |
| 53 | |
| 54 | newdst = 0; |
| 55 | |
| 56 | rcu_read_lock(); |
| 57 | indev = __in_dev_get_rcu(skb->dev); |
| 58 | if (indev != NULL) { |
| 59 | ifa = indev->ifa_list; |
| 60 | newdst = ifa->ifa_local; |
| 61 | } |
| 62 | rcu_read_unlock(); |
| 63 | |
| 64 | if (!newdst) |
| 65 | return NF_DROP; |
| 66 | } |
| 67 | |
| 68 | /* Transfer from original range. */ |
| 69 | memset(&newrange.min_addr, 0, sizeof(newrange.min_addr)); |
| 70 | memset(&newrange.max_addr, 0, sizeof(newrange.max_addr)); |
| 71 | newrange.flags = mr->range[0].flags | NF_NAT_RANGE_MAP_IPS; |
| 72 | newrange.min_addr.ip = newdst; |
| 73 | newrange.max_addr.ip = newdst; |
| 74 | newrange.min_proto = mr->range[0].min; |
| 75 | newrange.max_proto = mr->range[0].max; |
| 76 | |
| 77 | /* Hand modified range to generic setup. */ |
| 78 | return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST); |
| 79 | } |
| 80 | EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv4); |
| 81 | |
Pablo Neira Ayuso | b59eaf9 | 2014-11-26 12:46:50 +0100 | [diff] [blame] | 82 | static const struct in6_addr loopback_addr = IN6ADDR_LOOPBACK_INIT; |
| 83 | |
| 84 | unsigned int |
| 85 | nf_nat_redirect_ipv6(struct sk_buff *skb, const struct nf_nat_range *range, |
| 86 | unsigned int hooknum) |
| 87 | { |
| 88 | struct nf_nat_range newrange; |
| 89 | struct in6_addr newdst; |
| 90 | enum ip_conntrack_info ctinfo; |
| 91 | struct nf_conn *ct; |
| 92 | |
| 93 | ct = nf_ct_get(skb, &ctinfo); |
| 94 | if (hooknum == NF_INET_LOCAL_OUT) { |
| 95 | newdst = loopback_addr; |
| 96 | } else { |
| 97 | struct inet6_dev *idev; |
| 98 | struct inet6_ifaddr *ifa; |
| 99 | bool addr = false; |
| 100 | |
| 101 | rcu_read_lock(); |
| 102 | idev = __in6_dev_get(skb->dev); |
| 103 | if (idev != NULL) { |
| 104 | list_for_each_entry(ifa, &idev->addr_list, if_list) { |
| 105 | newdst = ifa->addr; |
| 106 | addr = true; |
| 107 | break; |
| 108 | } |
| 109 | } |
| 110 | rcu_read_unlock(); |
| 111 | |
| 112 | if (!addr) |
| 113 | return NF_DROP; |
| 114 | } |
| 115 | |
| 116 | newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS; |
| 117 | newrange.min_addr.in6 = newdst; |
| 118 | newrange.max_addr.in6 = newdst; |
| 119 | newrange.min_proto = range->min_proto; |
| 120 | newrange.max_proto = range->max_proto; |
| 121 | |
| 122 | return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST); |
| 123 | } |
| 124 | EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv6); |
| 125 | |
Arturo Borrero | 8b13edd | 2014-10-16 12:23:29 +0200 | [diff] [blame] | 126 | MODULE_LICENSE("GPL"); |
| 127 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |