/*
 * Copyright (c) 2021 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include "pnat.h"
#include <vnet/vnet.h>
#include <pnat/pnat.api_enum.h>
#include <pnat/pnat.api_types.h>
#include <vlibmemory/api.h>
#include <vnet/fib/fib_table.h>
#include <vnet/ip/ip.h>
#include <vnet/ip/ip_types_api.h>
#include <vnet/ip/reass/ip4_sv_reass.h>
#include <vnet/ip/reass/ip6_full_reass.h>
#include <vnet/ip/reass/ip6_sv_reass.h>
#include <vpp/app/version.h>

/*
 * This file contains the API handlers for the pnat.api
 */

#define REPLY_MSG_ID_BASE pm->msg_id_base
#include <vlibapi/api_helper_macros.h>

static void vl_api_pnat_binding_add_t_handler(vl_api_pnat_binding_add_t *mp) {
    pnat_main_t *pm = &pnat_main;
    vl_api_pnat_binding_add_reply_t *rmp;
    u32 binding_index;

    // for backward compatibility
    if (mp->match.proto == 0)
        mp->match.mask |= PNAT_PROTO;

    int rv = pnat_binding_add(&mp->match, &mp->rewrite, &binding_index);
    REPLY_MACRO2_END(VL_API_PNAT_BINDING_ADD_REPLY,
                     ({ rmp->binding_index = binding_index; }));
}

static void
vl_api_pnat_binding_add_v2_t_handler(vl_api_pnat_binding_add_t *mp) {
    pnat_main_t *pm = &pnat_main;
    vl_api_pnat_binding_add_reply_t *rmp;
    u32 binding_index;
    int rv = pnat_binding_add(&mp->match, &mp->rewrite, &binding_index);
    REPLY_MACRO2_END(VL_API_PNAT_BINDING_ADD_V2_REPLY,
                     ({ rmp->binding_index = binding_index; }));
}

static void
vl_api_pnat_binding_attach_t_handler(vl_api_pnat_binding_attach_t *mp) {
    pnat_main_t *pm = &pnat_main;
    vl_api_pnat_binding_attach_reply_t *rmp;
    int rv;

    VALIDATE_SW_IF_INDEX_END(mp);

    rv =
        pnat_binding_attach(mp->sw_if_index, mp->attachment, mp->binding_index);

bad_sw_if_index:
    REPLY_MACRO_END(VL_API_PNAT_BINDING_ATTACH_REPLY);
}

static void
vl_api_pnat_binding_detach_t_handler(vl_api_pnat_binding_detach_t *mp) {
    pnat_main_t *pm = &pnat_main;
    vl_api_pnat_binding_detach_reply_t *rmp;
    int rv;

    VALIDATE_SW_IF_INDEX_END(mp);

    rv =
        pnat_binding_detach(mp->sw_if_index, mp->attachment, mp->binding_index);

bad_sw_if_index:
    REPLY_MACRO_END(VL_API_PNAT_BINDING_DETACH_REPLY);
}

static void vl_api_pnat_binding_del_t_handler(vl_api_pnat_binding_del_t *mp) {
    pnat_main_t *pm = &pnat_main;
    vl_api_pnat_binding_del_reply_t *rmp;
    int rv = pnat_binding_del(mp->binding_index);
    REPLY_MACRO_END(VL_API_PNAT_BINDING_DEL_REPLY);
}

/*
 * Workaround for a bug in vppapigen that doesn't register the endian handler
 * for _details messages. When that's fixed it should be possible to use
 * REPLY_MACRO_DETAILS4_END and not have to care about endian-ness in the
 * handler itself.
 */
#define vl_endianfun
#include <pnat/pnat.api.h>
#undef vl_endianfun
static void send_bindings_details(u32 index, vl_api_registration_t *rp,
                                  u32 context) {
    pnat_main_t *pm = &pnat_main;
    vl_api_pnat_bindings_details_t *rmp;
    pnat_translation_t *t = pool_elt_at_index(pm->translations, index);

    /* Make sure every field is initiated (or don't skip the clib_memset()) */

    REPLY_MACRO_DETAILS4(VL_API_PNAT_BINDINGS_DETAILS, rp, context, ({
                             rmp->match = t->match;
                             rmp->rewrite = t->rewrite;

                             /* Endian hack until apigen registers _details
                              * endian functions */
                             vl_api_pnat_bindings_details_t_endian(rmp);
                             rmp->_vl_msg_id = htons(rmp->_vl_msg_id);
                             rmp->context = htonl(rmp->context);
                         }));
}

static void vl_api_pnat_bindings_get_t_handler(vl_api_pnat_bindings_get_t *mp) {
    pnat_main_t *pm = &pnat_main;
    vl_api_pnat_bindings_get_reply_t *rmp;

    i32 rv = 0;

    if (pool_elts(pm->translations) == 0) {
        REPLY_MACRO(VL_API_PNAT_BINDINGS_GET_REPLY);
        return;
    }

    /*
     * "cursor" comes from the get call, and allows client to continue a dump
     */
    REPLY_AND_DETAILS_MACRO(VL_API_PNAT_BINDINGS_GET_REPLY, pm->translations, ({
                                send_bindings_details(cursor, rp, mp->context);
                            }));
}

static void send_interfaces_details(u32 index, vl_api_registration_t *rp,
                                    u32 context) {
    pnat_main_t *pm = &pnat_main;
    vl_api_pnat_interfaces_details_t *rmp;
    pnat_interface_t *i = pool_elt_at_index(pm->interfaces, index);

    /* Make sure every field is initiated (or don't skip the clib_memset()) */

    REPLY_MACRO_DETAILS4(
        VL_API_PNAT_INTERFACES_DETAILS, rp, context, ({
            rmp->sw_if_index = i->sw_if_index;
            clib_memcpy(rmp->enabled, i->enabled, sizeof(rmp->enabled));
            clib_memcpy(rmp->lookup_mask, i->lookup_mask,
                        sizeof(rmp->lookup_mask));

            /* Endian hack until apigen registers _details
             * endian functions */
            vl_api_pnat_interfaces_details_t_endian(rmp);
            rmp->_vl_msg_id = htons(rmp->_vl_msg_id);
            rmp->context = htonl(rmp->context);
        }));
}

static void
vl_api_pnat_interfaces_get_t_handler(vl_api_pnat_interfaces_get_t *mp) {
    pnat_main_t *pm = &pnat_main;
    vl_api_pnat_interfaces_get_reply_t *rmp;

    i32 rv = 0;

    if (pool_elts(pm->interfaces) == 0) {
        REPLY_MACRO(VL_API_PNAT_INTERFACES_GET_REPLY);
        return;
    }

    /*
     * "cursor" comes from the get call, and allows client to continue a dump
     */
    REPLY_AND_DETAILS_MACRO(
        VL_API_PNAT_INTERFACES_GET_REPLY, pm->interfaces,
        ({ send_interfaces_details(cursor, rp, mp->context); }));
}

/* API definitions */
#include <vnet/format_fns.h>
#include <pnat/pnat.api.c>

/* Set up the API message handling tables */
clib_error_t *pnat_plugin_api_hookup(vlib_main_t *vm) {
    pnat_main_t *pm = &pnat_main;

    pm->msg_id_base = setup_message_id_table();

    return 0;
}

/*
 * Register the plugin and hook up the API
 */
#include <vnet/plugin/plugin.h>
VLIB_PLUGIN_REGISTER() = {
    .version = VPP_BUILD_VER,
    .description = "Policy 1:1 NAT",
};

clib_error_t *pnat_init(vlib_main_t *vm) {
    pnat_main_t *pm = &pnat_main;
    memset(pm, 0, sizeof(*pm));

    return pnat_plugin_api_hookup(vm);
}

VLIB_INIT_FUNCTION(pnat_init);