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/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>
30 static const struct in6_addr loopback_addr
= IN6ADDR_LOOPBACK_INIT
;
33 redirect_tg6(struct sk_buff
*skb
, const struct xt_action_param
*par
)
35 const struct nf_nat_range
*range
= par
->targinfo
;
36 struct nf_nat_range newrange
;
37 struct in6_addr newdst
;
38 enum ip_conntrack_info ctinfo
;
41 ct
= nf_ct_get(skb
, &ctinfo
);
42 if (par
->hooknum
== NF_INET_LOCAL_OUT
)
43 newdst
= loopback_addr
;
45 struct inet6_dev
*idev
;
46 struct inet6_ifaddr
*ifa
;
50 idev
= __in6_dev_get(skb
->dev
);
52 list_for_each_entry(ifa
, &idev
->addr_list
, if_list
) {
64 newrange
.flags
= range
->flags
| NF_NAT_RANGE_MAP_IPS
;
65 newrange
.min_addr
.in6
= newdst
;
66 newrange
.max_addr
.in6
= newdst
;
67 newrange
.min_proto
= range
->min_proto
;
68 newrange
.max_proto
= range
->max_proto
;
70 return nf_nat_setup_info(ct
, &newrange
, NF_NAT_MANIP_DST
);
73 static int redirect_tg6_checkentry(const struct xt_tgchk_param
*par
)
75 const struct nf_nat_range
*range
= par
->targinfo
;
77 if (range
->flags
& NF_NAT_RANGE_MAP_IPS
)
82 /* FIXME: Take multiple ranges --RR */
83 static int redirect_tg4_check(const struct xt_tgchk_param
*par
)
85 const struct nf_nat_ipv4_multi_range_compat
*mr
= par
->targinfo
;
87 if (mr
->range
[0].flags
& NF_NAT_RANGE_MAP_IPS
) {
88 pr_debug("bad MAP_IPS.\n");
91 if (mr
->rangesize
!= 1) {
92 pr_debug("bad rangesize %u.\n", mr
->rangesize
);
99 redirect_tg4(struct sk_buff
*skb
, const struct xt_action_param
*par
)
102 enum ip_conntrack_info ctinfo
;
104 const struct nf_nat_ipv4_multi_range_compat
*mr
= par
->targinfo
;
105 struct nf_nat_range newrange
;
107 NF_CT_ASSERT(par
->hooknum
== NF_INET_PRE_ROUTING
||
108 par
->hooknum
== NF_INET_LOCAL_OUT
);
110 ct
= nf_ct_get(skb
, &ctinfo
);
111 NF_CT_ASSERT(ct
&& (ctinfo
== IP_CT_NEW
|| ctinfo
== IP_CT_RELATED
));
113 /* Local packets: make them go to loopback */
114 if (par
->hooknum
== NF_INET_LOCAL_OUT
)
115 newdst
= htonl(0x7F000001);
117 struct in_device
*indev
;
118 struct in_ifaddr
*ifa
;
123 indev
= __in_dev_get_rcu(skb
->dev
);
124 if (indev
&& (ifa
= indev
->ifa_list
))
125 newdst
= ifa
->ifa_local
;
132 /* Transfer from original range. */
133 memset(&newrange
.min_addr
, 0, sizeof(newrange
.min_addr
));
134 memset(&newrange
.max_addr
, 0, sizeof(newrange
.max_addr
));
135 newrange
.flags
= mr
->range
[0].flags
| NF_NAT_RANGE_MAP_IPS
;
136 newrange
.min_addr
.ip
= newdst
;
137 newrange
.max_addr
.ip
= newdst
;
138 newrange
.min_proto
= mr
->range
[0].min
;
139 newrange
.max_proto
= mr
->range
[0].max
;
141 /* Hand modified range to generic setup. */
142 return nf_nat_setup_info(ct
, &newrange
, NF_NAT_MANIP_DST
);
145 static struct xt_target redirect_tg_reg
[] __read_mostly
= {
148 .family
= NFPROTO_IPV6
,
151 .checkentry
= redirect_tg6_checkentry
,
152 .target
= redirect_tg6
,
153 .targetsize
= sizeof(struct nf_nat_range
),
154 .hooks
= (1 << NF_INET_PRE_ROUTING
) |
155 (1 << NF_INET_LOCAL_OUT
),
160 .family
= NFPROTO_IPV4
,
163 .target
= redirect_tg4
,
164 .checkentry
= redirect_tg4_check
,
165 .targetsize
= sizeof(struct nf_nat_ipv4_multi_range_compat
),
166 .hooks
= (1 << NF_INET_PRE_ROUTING
) |
167 (1 << NF_INET_LOCAL_OUT
),
172 static int __init
redirect_tg_init(void)
174 return xt_register_targets(redirect_tg_reg
,
175 ARRAY_SIZE(redirect_tg_reg
));
178 static void __exit
redirect_tg_exit(void)
180 xt_unregister_targets(redirect_tg_reg
, ARRAY_SIZE(redirect_tg_reg
));
183 module_init(redirect_tg_init
);
184 module_exit(redirect_tg_exit
);
186 MODULE_LICENSE("GPL");
187 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
188 MODULE_DESCRIPTION("Xtables: Connection redirection to localhost");
189 MODULE_ALIAS("ip6t_REDIRECT");
190 MODULE_ALIAS("ipt_REDIRECT");