191 lines
4.9 KiB
C
191 lines
4.9 KiB
C
/*
|
|
* (C) 1999-2001 Paul `Rusty' Russell
|
|
* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
|
|
* Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* Based on Rusty Russell's IPv4 REDIRECT target. Development of IPv6
|
|
* NAT funded by Astaro.
|
|
*/
|
|
|
|
#include <linux/if.h>
|
|
#include <linux/inetdevice.h>
|
|
#include <linux/ip.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/netfilter.h>
|
|
#include <linux/types.h>
|
|
#include <linux/netfilter_ipv4.h>
|
|
#include <linux/netfilter_ipv6.h>
|
|
#include <linux/netfilter/x_tables.h>
|
|
#include <net/addrconf.h>
|
|
#include <net/checksum.h>
|
|
#include <net/protocol.h>
|
|
#include <net/netfilter/nf_nat.h>
|
|
|
|
static const struct in6_addr loopback_addr = IN6ADDR_LOOPBACK_INIT;
|
|
|
|
static unsigned int
|
|
redirect_tg6(struct sk_buff *skb, const struct xt_action_param *par)
|
|
{
|
|
const struct nf_nat_range *range = par->targinfo;
|
|
struct nf_nat_range newrange;
|
|
struct in6_addr newdst;
|
|
enum ip_conntrack_info ctinfo;
|
|
struct nf_conn *ct;
|
|
|
|
ct = nf_ct_get(skb, &ctinfo);
|
|
if (par->hooknum == NF_INET_LOCAL_OUT)
|
|
newdst = loopback_addr;
|
|
else {
|
|
struct inet6_dev *idev;
|
|
struct inet6_ifaddr *ifa;
|
|
bool addr = false;
|
|
|
|
rcu_read_lock();
|
|
idev = __in6_dev_get(skb->dev);
|
|
if (idev != NULL) {
|
|
list_for_each_entry(ifa, &idev->addr_list, if_list) {
|
|
newdst = ifa->addr;
|
|
addr = true;
|
|
break;
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
if (!addr)
|
|
return NF_DROP;
|
|
}
|
|
|
|
newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS;
|
|
newrange.min_addr.in6 = newdst;
|
|
newrange.max_addr.in6 = newdst;
|
|
newrange.min_proto = range->min_proto;
|
|
newrange.max_proto = range->max_proto;
|
|
|
|
return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST);
|
|
}
|
|
|
|
static int redirect_tg6_checkentry(const struct xt_tgchk_param *par)
|
|
{
|
|
const struct nf_nat_range *range = par->targinfo;
|
|
|
|
if (range->flags & NF_NAT_RANGE_MAP_IPS)
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
/* FIXME: Take multiple ranges --RR */
|
|
static int redirect_tg4_check(const struct xt_tgchk_param *par)
|
|
{
|
|
const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
|
|
|
|
if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) {
|
|
pr_debug("bad MAP_IPS.\n");
|
|
return -EINVAL;
|
|
}
|
|
if (mr->rangesize != 1) {
|
|
pr_debug("bad rangesize %u.\n", mr->rangesize);
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int
|
|
redirect_tg4(struct sk_buff *skb, const struct xt_action_param *par)
|
|
{
|
|
struct nf_conn *ct;
|
|
enum ip_conntrack_info ctinfo;
|
|
__be32 newdst;
|
|
const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
|
|
struct nf_nat_range newrange;
|
|
|
|
NF_CT_ASSERT(par->hooknum == NF_INET_PRE_ROUTING ||
|
|
par->hooknum == NF_INET_LOCAL_OUT);
|
|
|
|
ct = nf_ct_get(skb, &ctinfo);
|
|
NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED));
|
|
|
|
/* Local packets: make them go to loopback */
|
|
if (par->hooknum == NF_INET_LOCAL_OUT)
|
|
newdst = htonl(0x7F000001);
|
|
else {
|
|
struct in_device *indev;
|
|
struct in_ifaddr *ifa;
|
|
|
|
newdst = 0;
|
|
|
|
rcu_read_lock();
|
|
indev = __in_dev_get_rcu(skb->dev);
|
|
if (indev && (ifa = indev->ifa_list))
|
|
newdst = ifa->ifa_local;
|
|
rcu_read_unlock();
|
|
|
|
if (!newdst)
|
|
return NF_DROP;
|
|
}
|
|
|
|
/* Transfer from original range. */
|
|
memset(&newrange.min_addr, 0, sizeof(newrange.min_addr));
|
|
memset(&newrange.max_addr, 0, sizeof(newrange.max_addr));
|
|
newrange.flags = mr->range[0].flags | NF_NAT_RANGE_MAP_IPS;
|
|
newrange.min_addr.ip = newdst;
|
|
newrange.max_addr.ip = newdst;
|
|
newrange.min_proto = mr->range[0].min;
|
|
newrange.max_proto = mr->range[0].max;
|
|
|
|
/* Hand modified range to generic setup. */
|
|
return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST);
|
|
}
|
|
|
|
static struct xt_target redirect_tg_reg[] __read_mostly = {
|
|
{
|
|
.name = "REDIRECT",
|
|
.family = NFPROTO_IPV6,
|
|
.revision = 0,
|
|
.table = "nat",
|
|
.checkentry = redirect_tg6_checkentry,
|
|
.target = redirect_tg6,
|
|
.targetsize = sizeof(struct nf_nat_range),
|
|
.hooks = (1 << NF_INET_PRE_ROUTING) |
|
|
(1 << NF_INET_LOCAL_OUT),
|
|
.me = THIS_MODULE,
|
|
},
|
|
{
|
|
.name = "REDIRECT",
|
|
.family = NFPROTO_IPV4,
|
|
.revision = 0,
|
|
.table = "nat",
|
|
.target = redirect_tg4,
|
|
.checkentry = redirect_tg4_check,
|
|
.targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat),
|
|
.hooks = (1 << NF_INET_PRE_ROUTING) |
|
|
(1 << NF_INET_LOCAL_OUT),
|
|
.me = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
static int __init redirect_tg_init(void)
|
|
{
|
|
return xt_register_targets(redirect_tg_reg,
|
|
ARRAY_SIZE(redirect_tg_reg));
|
|
}
|
|
|
|
static void __exit redirect_tg_exit(void)
|
|
{
|
|
xt_unregister_targets(redirect_tg_reg, ARRAY_SIZE(redirect_tg_reg));
|
|
}
|
|
|
|
module_init(redirect_tg_init);
|
|
module_exit(redirect_tg_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
|
|
MODULE_DESCRIPTION("Xtables: Connection redirection to localhost");
|
|
MODULE_ALIAS("ip6t_REDIRECT");
|
|
MODULE_ALIAS("ipt_REDIRECT");
|