output-json-mqtt.c

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/* Copyright (C) 2020-2021 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.
 */
 
/**
 * \file
 *
 * \author Sascha Steinbiss <sascha@steinbiss.name>
 */
 
#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 "util-misc.h"
 
#include "output.h"
#include "output-json.h"
 
#include "app-layer.h"
#include "app-layer-parser.h"
 
#include "output-json-mqtt.h"
#include "rust.h"
 
#define MQTT_LOG_PASSWORDS BIT_U32(0)
#define MQTT_DEFAULT_FLAGS     (MQTT_LOG_PASSWORDS)
#define MQTT_DEFAULT_MAXLOGLEN 1024
 
typedef struct LogMQTTFileCtx_ {
    uint32_t flags, max_log_len;
    OutputJsonCtx *eve_ctx;
} LogMQTTFileCtx;
 
typedef struct LogMQTTLogThread_ {
    LogMQTTFileCtx *mqttlog_ctx;
    uint32_t        count;
    OutputJsonThreadCtx *ctx;
} LogMQTTLogThread;
 
bool JsonMQTTAddMetadata(void *vtx, SCJsonBuilder *js)
{
    return SCMqttLoggerLog(vtx, MQTT_DEFAULT_FLAGS, MQTT_DEFAULT_MAXLOGLEN, js);
}
 
static int JsonMQTTLogger(ThreadVars *tv, void *thread_data,
    const Packet *p, Flow *f, void *state, void *tx, uint64_t tx_id)
{
    LogMQTTLogThread *thread = thread_data;
    enum SCOutputJsonLogDirection dir;
 
    if (SCMqttTxIsToClient((MQTTTransaction *)tx)) {
        dir = LOG_DIR_FLOW_TOCLIENT;
    } else {
        dir = LOG_DIR_FLOW_TOSERVER;
    }
 
    SCJsonBuilder *js = CreateEveHeader(p, dir, "mqtt", NULL, thread->mqttlog_ctx->eve_ctx);
    if (unlikely(js == NULL)) {
        return TM_ECODE_FAILED;
    }
 
    if (!SCMqttLoggerLog(tx, thread->mqttlog_ctx->flags, thread->mqttlog_ctx->max_log_len, js))
        goto error;
 
    OutputJsonBuilderBuffer(tv, p, p->flow, js, thread->ctx);
    SCJbFree(js);
 
    return TM_ECODE_OK;
 
error:
    SCJbFree(js);
    return TM_ECODE_FAILED;
}
 
static void OutputMQTTLogDeInitCtxSub(OutputCtx *output_ctx)
{
    LogMQTTFileCtx *mqttlog_ctx = (LogMQTTFileCtx *)output_ctx->data;
    SCFree(mqttlog_ctx);
    SCFree(output_ctx);
}
 
static void JsonMQTTLogParseConfig(SCConfNode *conf, LogMQTTFileCtx *mqttlog_ctx)
{
    const char *query = SCConfNodeLookupChildValue(conf, "passwords");
    if (query != NULL) {
        if (SCConfValIsTrue(query)) {
            mqttlog_ctx->flags |= MQTT_LOG_PASSWORDS;
        } else {
            mqttlog_ctx->flags &= ~MQTT_LOG_PASSWORDS;
        }
    } else {
        mqttlog_ctx->flags |= MQTT_LOG_PASSWORDS;
    }
    uint32_t max_log_len = MQTT_DEFAULT_MAXLOGLEN;
    query = SCConfNodeLookupChildValue(conf, "string-log-limit");
    if (query != NULL) {
        if (ParseSizeStringU32(query, &max_log_len) < 0) {
            SCLogError("Error parsing string-log-limit from config - %s, ", query);
            exit(EXIT_FAILURE);
        }
    }
    mqttlog_ctx->max_log_len = max_log_len;
}
 
static OutputInitResult OutputMQTTLogInitSub(SCConfNode *conf, OutputCtx *parent_ctx)
{
    OutputInitResult result = { NULL, false };
    OutputJsonCtx *ajt = parent_ctx->data;
 
    LogMQTTFileCtx *mqttlog_ctx = SCCalloc(1, sizeof(*mqttlog_ctx));
    if (unlikely(mqttlog_ctx == NULL)) {
        return result;
    }
    mqttlog_ctx->eve_ctx = ajt;
 
    OutputCtx *output_ctx = SCCalloc(1, sizeof(*output_ctx));
    if (unlikely(output_ctx == NULL)) {
        SCFree(mqttlog_ctx);
        return result;
    }
    output_ctx->data = mqttlog_ctx;
    output_ctx->DeInit = OutputMQTTLogDeInitCtxSub;
 
    JsonMQTTLogParseConfig(conf, mqttlog_ctx);
 
    AppLayerParserRegisterLogger(IPPROTO_TCP, ALPROTO_MQTT);
 
    result.ctx = output_ctx;
    result.ok = true;
    return result;
}
 
static TmEcode JsonMQTTLogThreadInit(ThreadVars *t, const void *initdata, void **data)
{
    LogMQTTLogThread *thread = SCCalloc(1, sizeof(*thread));
    if (unlikely(thread == NULL)) {
        return TM_ECODE_FAILED;
    }
 
    if (initdata == NULL) {
        SCLogDebug("Error getting context for EveLogMQTT.  \"initdata\" is NULL.");
        SCFree(thread);
        return TM_ECODE_FAILED;
    }
 
    thread->mqttlog_ctx = ((OutputCtx *)initdata)->data;
    thread->ctx = CreateEveThreadCtx(t, thread->mqttlog_ctx->eve_ctx);
    if (unlikely(thread->ctx == NULL)) {
        SCFree(thread);
        return TM_ECODE_FAILED;
    }
 
    *data = (void *)thread;
 
    return TM_ECODE_OK;
}
 
static TmEcode JsonMQTTLogThreadDeinit(ThreadVars *t, void *data)
{
    LogMQTTLogThread *thread = (LogMQTTLogThread *)data;
    if (thread == NULL) {
        return TM_ECODE_OK;
    }
    FreeEveThreadCtx(thread->ctx);
    SCFree(thread);
    return TM_ECODE_OK;
}
 
void JsonMQTTLogRegister(void)
{
    OutputRegisterTxSubModule(LOGGER_JSON_TX, "eve-log", "JsonMQTTLog", "eve-log.mqtt",
            OutputMQTTLogInitSub, ALPROTO_MQTT, JsonMQTTLogger, JsonMQTTLogThreadInit,
            JsonMQTTLogThreadDeinit);
}