/*-
 * 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/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);