/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2015-2019 Yandex LLC
 * Copyright (c) 2015-2019 Andrey V. Elsukov <ae@FreeBSD.org>
 *
 * 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>
#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 "ip_fw_nat64.h"
#include "nat64_translate.h"

VNET_DEFINE(int, nat64_debug) = 0;

SYSCTL_DECL(_net_inet_ip_fw);
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, nat64_debug, CTLFLAG_VNET | CTLFLAG_RW,
    &VNET_NAME(nat64_debug), 0, "Debug level for NAT64 module");

static int
sysctl_direct_output(SYSCTL_HANDLER_ARGS)
{
	uint32_t value;
	int error;

	value = nat64_get_output_method();
	error = sysctl_handle_32(oidp, &value, 0, req);
	/* Read operation or some error */
	if ((error != 0) || (req->newptr == NULL))
		return (error);
	nat64_set_output_method(value);
	return (0);
}
SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, nat64_direct_output,
    CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
    0, 0, sysctl_direct_output, "IU",
    "Use if_output directly instead of deffered netisr-based processing");

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;
	/* Initialize V_nat64out methods explicitly. */
	nat64_set_output_method(0);
	error = nat64stl_init(ch, first);
	if (error != 0)
		return (error);
	error = nat64clat_init(ch, first);
	if (error != 0) {
		nat64stl_uninit(ch, first);
		return (error);
	}
	error = nat64lsn_init(ch, first);
	if (error != 0) {
		nat64stl_uninit(ch, first);
		nat64clat_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);
	nat64clat_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);