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>
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.
10 * Based on Rusty Russell's IPv4 REDIRECT target. Development of IPv6
11 * NAT funded by Astaro.
15 #include <linux/inetdevice.h>
17 #include <linux/kernel.h>
18 #include <linux/netdevice.h>
19 #include <linux/netfilter.h>
20 #include <linux/types.h>
21 #include <linux/netfilter_ipv4.h>
22 #include <linux/netfilter_ipv6.h>
23 #include <linux/netfilter/x_tables.h>
24 #include <net/addrconf.h>
25 #include <net/checksum.h>
26 #include <net/protocol.h>
27 #include <net/netfilter/nf_nat.h>
28 #include <net/netfilter/nf_nat_redirect.h>
31 nf_nat_redirect_ipv4(struct sk_buff *skb,
32 const struct nf_nat_ipv4_multi_range_compat *mr,
36 enum ip_conntrack_info ctinfo;
38 struct nf_nat_range2 newrange;
40 WARN_ON(hooknum != NF_INET_PRE_ROUTING &&
41 hooknum != NF_INET_LOCAL_OUT);
43 ct = nf_ct_get(skb, &ctinfo);
44 WARN_ON(!(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED)));
46 /* Local packets: make them go to loopback */
47 if (hooknum == NF_INET_LOCAL_OUT) {
48 newdst = htonl(0x7F000001);
50 struct in_device *indev;
51 struct in_ifaddr *ifa;
55 indev = __in_dev_get_rcu(skb->dev);
56 if (indev && indev->ifa_list) {
57 ifa = indev->ifa_list;
58 newdst = ifa->ifa_local;
65 /* Transfer from original range. */
66 memset(&newrange.min_addr, 0, sizeof(newrange.min_addr));
67 memset(&newrange.max_addr, 0, sizeof(newrange.max_addr));
68 newrange.flags = mr->range[0].flags | NF_NAT_RANGE_MAP_IPS;
69 newrange.min_addr.ip = newdst;
70 newrange.max_addr.ip = newdst;
71 newrange.min_proto = mr->range[0].min;
72 newrange.max_proto = mr->range[0].max;
74 /* Hand modified range to generic setup. */
75 return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST);
77 EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv4);
79 static const struct in6_addr loopback_addr = IN6ADDR_LOOPBACK_INIT;
82 nf_nat_redirect_ipv6(struct sk_buff *skb, const struct nf_nat_range2 *range,
85 struct nf_nat_range2 newrange;
86 struct in6_addr newdst;
87 enum ip_conntrack_info ctinfo;
90 ct = nf_ct_get(skb, &ctinfo);
91 if (hooknum == NF_INET_LOCAL_OUT) {
92 newdst = loopback_addr;
94 struct inet6_dev *idev;
95 struct inet6_ifaddr *ifa;
98 idev = __in6_dev_get(skb->dev);
100 read_lock_bh(&idev->lock);
101 list_for_each_entry(ifa, &idev->addr_list, if_list) {
106 read_unlock_bh(&idev->lock);
113 newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS;
114 newrange.min_addr.in6 = newdst;
115 newrange.max_addr.in6 = newdst;
116 newrange.min_proto = range->min_proto;
117 newrange.max_proto = range->max_proto;
119 return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST);
121 EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv6);