/* Copyright (C) 2019-2020 Open Information Security Foundation

 *

 * You can copy, redistribute or modify this Program under the terms of

 * the GNU General Public License version 2 as published by the Free

 * Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * version 2 along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

 * 02110-1301, USA.

 */

#include "suricata-common.h"

#include "detect.h"

#include "pkt-var.h"

#include "conf.h"

#include "threads.h"

#include "threadvars.h"

#include "tm-threads.h"

#include "util-unittest.h"

#include "util-buffer.h"

#include "util-debug.h"

#include "util-byte.h"

#include "output.h"

#include "output-json.h"

#include "app-layer.h"

#include "app-layer-parser.h"

#include "output-json-modbus.h"

#include "rust.h"

typedef struct LogModbusFileCtx_ {

    LogFileCtx *file_ctx;

    OutputJsonCtx *eve_ctx;

} LogModbusFileCtx;

typedef struct JsonModbusLogThread_ {

    LogModbusFileCtx *modbuslog_ctx;

    OutputJsonThreadCtx *ctx;

} JsonModbusLogThread;

static int JsonModbusLogger(ThreadVars *tv, void *thread_data, const Packet *p, Flow *f,

        void *state, void *tx, uint64_t tx_id)

{

    JsonModbusLogThread *thread = thread_data;

    JsonBuilder *js =

            CreateEveHeader(p, LOG_DIR_FLOW, "modbus", NULL, thread->modbuslog_ctx->eve_ctx);

    if (unlikely(js == NULL)) {

        return TM_ECODE_OK;

    }

    if (!rs_modbus_to_json(tx, js)) {

        jb_free(js);

        return TM_ECODE_FAILED;

    }

    OutputJsonBuilderBuffer(js, thread->ctx);

    jb_free(js);

    return TM_ECODE_OK;

}

static void OutputModbusLogDeInitCtxSub(OutputCtx *output_ctx)

{

    LogModbusFileCtx *modbuslog_ctx = (LogModbusFileCtx *)output_ctx->data;

    SCFree(modbuslog_ctx);

    SCFree(output_ctx);

}

static OutputInitResult OutputModbusLogInitSub(ConfNode *conf, OutputCtx *parent_ctx)

{

    OutputInitResult result = { NULL, false };

    OutputJsonCtx *ajt = parent_ctx->data;

    LogModbusFileCtx *modbuslog_ctx = SCCalloc(1, sizeof(*modbuslog_ctx));

    if (unlikely(modbuslog_ctx == NULL)) {

        return result;

    }

    modbuslog_ctx->file_ctx = ajt->file_ctx;

    modbuslog_ctx->eve_ctx = ajt;

    OutputCtx *output_ctx = SCCalloc(1, sizeof(*output_ctx));

    if (unlikely(output_ctx == NULL)) {

        SCFree(modbuslog_ctx);

        return result;

    }

    output_ctx->data = modbuslog_ctx;

    output_ctx->DeInit = OutputModbusLogDeInitCtxSub;

    AppLayerParserRegisterLogger(IPPROTO_TCP, ALPROTO_MODBUS);

    SCLogDebug("modbus log sub-module initialized.");

    result.ctx = output_ctx;

    result.ok = true;

    return result;

}

static TmEcode JsonModbusLogThreadInit(ThreadVars *t, const void *initdata, void **data)

{

    if (initdata == NULL) {

        SCLogDebug("Error getting context for EveLogModbus. \"initdata\" is NULL.");

        return TM_ECODE_FAILED;

    }

    JsonModbusLogThread *thread = SCCalloc(1, sizeof(*thread));

    if (unlikely(thread == NULL)) {

        return TM_ECODE_FAILED;

    }

    thread->modbuslog_ctx = ((OutputCtx *)initdata)->data;

    thread->ctx = CreateEveThreadCtx(t, thread->modbuslog_ctx->eve_ctx);

    if (thread->ctx == NULL) {

        goto error_exit;

    }

    *data = (void *)thread;

    return TM_ECODE_OK;

error_exit:

    SCFree(thread);

    return TM_ECODE_FAILED;

}

static TmEcode JsonModbusLogThreadDeinit(ThreadVars *t, void *data)

{

    JsonModbusLogThread *thread = (JsonModbusLogThread *)data;

    if (thread == NULL) {

        return TM_ECODE_OK;

    }

    FreeEveThreadCtx(thread->ctx);

    SCFree(thread);

    return TM_ECODE_OK;

}

bool JsonModbusAddMetadata(const Flow *f, uint64_t tx_id, JsonBuilder *js)

{

    void *state = FlowGetAppState(f);

    if (state) {

        void *tx = AppLayerParserGetTx(f->proto, ALPROTO_MODBUS, state, tx_id);

        if (tx) {

            return rs_modbus_to_json(tx, js);

        }

    }

    return false;

}

void JsonModbusLogRegister(void)

{

    /* Register as an eve sub-module. */

    OutputRegisterTxSubModule(LOGGER_JSON_TX, "eve-log", "JsonModbusLog", "eve-log.modbus",

            OutputModbusLogInitSub, ALPROTO_MODBUS, JsonModbusLogger, JsonModbusLogThreadInit,

            JsonModbusLogThreadDeinit, NULL);

    SCLogDebug("modbus json logger registered.");

}