freebsd-dev/sys/netpfil/ipfw/nat64/ip_fw_nat64.c
Andrey V. Elsukov d8caf56e9e Add ipfw_nat64 module that implements stateless and stateful NAT64.
The module works together with ipfw(4) and implemented as its external
action module.

Stateless NAT64 registers external action with name nat64stl. This
keyword should be used to create NAT64 instance and to address this
instance in rules. Stateless NAT64 uses two lookup tables with mapped
IPv4->IPv6 and IPv6->IPv4 addresses to perform translation.

A configuration of instance should looks like this:
 1. Create lookup tables:
 # ipfw table T46 create type addr valtype ipv6
 # ipfw table T64 create type addr valtype ipv4
 2. Fill T46 and T64 tables.
 3. Add rule to allow neighbor solicitation and advertisement:
 # ipfw add allow icmp6 from any to any icmp6types 135,136
 4. Create NAT64 instance:
 # ipfw nat64stl NAT create table4 T46 table6 T64
 5. Add rules that matches the traffic:
 # ipfw add nat64stl NAT ip from any to table(T46)
 # ipfw add nat64stl NAT ip from table(T64) to 64:ff9b::/96
 6. Configure DNS64 for IPv6 clients and add route to 64:ff9b::/96
    via NAT64 host.

Stateful NAT64 registers external action with name nat64lsn. The only
one option required to create nat64lsn instance - prefix4. It defines
the pool of IPv4 addresses used for translation.

A configuration of instance should looks like this:
 1. Add rule to allow neighbor solicitation and advertisement:
 # ipfw add allow icmp6 from any to any icmp6types 135,136
 2. Create NAT64 instance:
 # ipfw nat64lsn NAT create prefix4 A.B.C.D/28
 3. Add rules that matches the traffic:
 # ipfw add nat64lsn NAT ip from any to A.B.C.D/28
 # ipfw add nat64lsn NAT ip6 from any to 64:ff9b::/96
 4. Configure DNS64 for IPv6 clients and add route to 64:ff9b::/96
    via NAT64 host.

Obtained from:	Yandex LLC
Relnotes:	yes
Sponsored by:	Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D6434
2016-08-13 16:09:49 +00:00

130 lines
3.7 KiB
C

/*-
* Copyright (c) 2015-2016 Yandex LLC
* Copyright (c) 2015-2016 Andrey V. Elsukov <ae@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/rwlock.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/ip_var.h>
#include <netinet/ip_fw.h>
#include <netpfil/ipfw/ip_fw_private.h>
#include <netpfil/ipfw/nat64/ip_fw_nat64.h>
#include <netpfil/ipfw/nat64/nat64_translate.h>
int nat64_debug = 0;
SYSCTL_DECL(_net_inet_ip_fw);
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, nat64_debug, CTLFLAG_RW,
&nat64_debug, 0, "Debug level for NAT64 module");
int nat64_allow_private = 0;
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, nat64_allow_private, CTLFLAG_RW,
&nat64_allow_private, 0,
"Allow use of non-global IPv4 addresses with NAT64");
static int
vnet_ipfw_nat64_init(const void *arg __unused)
{
struct ip_fw_chain *ch;
int first, error;
ch = &V_layer3_chain;
first = IS_DEFAULT_VNET(curvnet) ? 1: 0;
error = nat64stl_init(ch, first);
if (error != 0)
return (error);
error = nat64lsn_init(ch, first);
if (error != 0) {
nat64stl_uninit(ch, first);
return (error);
}
return (0);
}
static int
vnet_ipfw_nat64_uninit(const void *arg __unused)
{
struct ip_fw_chain *ch;
int last;
ch = &V_layer3_chain;
last = IS_DEFAULT_VNET(curvnet) ? 1: 0;
nat64stl_uninit(ch, last);
nat64lsn_uninit(ch, last);
return (0);
}
static int
ipfw_nat64_modevent(module_t mod, int type, void *unused)
{
switch (type) {
case MOD_LOAD:
case MOD_UNLOAD:
break;
default:
return (EOPNOTSUPP);
}
return (0);
}
static moduledata_t ipfw_nat64_mod = {
"ipfw_nat64",
ipfw_nat64_modevent,
0
};
/* Define startup order. */
#define IPFW_NAT64_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN
#define IPFW_NAT64_MODEVENT_ORDER (SI_ORDER_ANY - 128) /* after ipfw */
#define IPFW_NAT64_MODULE_ORDER (IPFW_NAT64_MODEVENT_ORDER + 1)
#define IPFW_NAT64_VNET_ORDER (IPFW_NAT64_MODEVENT_ORDER + 2)
DECLARE_MODULE(ipfw_nat64, ipfw_nat64_mod, IPFW_NAT64_SI_SUB_FIREWALL,
SI_ORDER_ANY);
MODULE_DEPEND(ipfw_nat64, ipfw, 3, 3, 3);
MODULE_VERSION(ipfw_nat64, 1);
VNET_SYSINIT(vnet_ipfw_nat64_init, IPFW_NAT64_SI_SUB_FIREWALL,
IPFW_NAT64_VNET_ORDER, vnet_ipfw_nat64_init, NULL);
VNET_SYSUNINIT(vnet_ipfw_nat64_uninit, IPFW_NAT64_SI_SUB_FIREWALL,
IPFW_NAT64_VNET_ORDER, vnet_ipfw_nat64_uninit, NULL);