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/* Copyright (C) 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.
*/
/**
*
* \author Sascha Steinbiss <sascha@steinbiss.name>
*
* Implements the mqtt.connect.willtopic sticky buffer
*/
#include "suricata-common.h"
#include "detect.h"
#include "detect-parse.h"
#include "detect-engine.h"
#include "detect-engine-mpm.h"
#include "detect-engine-prefilter.h"
#include "detect-mqtt-connect-willtopic.h"
#include "rust.h"
#define KEYWORD_NAME "mqtt.connect.willtopic"
#define KEYWORD_DOC "mqtt-keywords.html#mqtt-connect-willtopic"
#define BUFFER_NAME "mqtt.connect.willtopic"
#define BUFFER_DESC "MQTT CONNECT will topic"
static int g_buffer_id = 0;
static int DetectMQTTConnectWillTopicSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg)
{
if (DetectBufferSetActiveList(de_ctx, s, g_buffer_id) < 0)
return -1;
if (DetectSignatureSetAppProto(s, ALPROTO_MQTT) < 0)
return -1;
return 0;
}
static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms,
Flow *_f, const uint8_t _flow_flags,
void *txv, const int list_id)
{
InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
if (buffer->inspect == NULL) {
const uint8_t *b = NULL;
uint32_t b_len = 0;
if (rs_mqtt_tx_get_connect_willtopic(txv, &b, &b_len) != 1)
return NULL;
if (b == NULL || b_len == 0)
return NULL;
InspectionBufferSetup(det_ctx, list_id, buffer, b, b_len);
InspectionBufferApplyTransforms(buffer, transforms);
}
return buffer;
}
void DetectMQTTConnectWillTopicRegister(void)
{
/* mqtt.connect.willtopic sticky buffer */
sigmatch_table[DETECT_AL_MQTT_CONNECT_WILLTOPIC].name = KEYWORD_NAME;
sigmatch_table[DETECT_AL_MQTT_CONNECT_WILLTOPIC].desc = "sticky buffer to match on the MQTT CONNECT will topic";
sigmatch_table[DETECT_AL_MQTT_CONNECT_WILLTOPIC].url = "/rules/" KEYWORD_DOC;
sigmatch_table[DETECT_AL_MQTT_CONNECT_WILLTOPIC].Setup = DetectMQTTConnectWillTopicSetup;
sigmatch_table[DETECT_AL_MQTT_CONNECT_WILLTOPIC].flags |= SIGMATCH_NOOPT;
DetectAppLayerInspectEngineRegister2(BUFFER_NAME, ALPROTO_MQTT,
SIG_FLAG_TOSERVER, 0,
DetectEngineInspectBufferGeneric, GetData);
DetectAppLayerMpmRegister2(BUFFER_NAME, SIG_FLAG_TOSERVER, 2,
PrefilterGenericMpmRegister, GetData, ALPROTO_MQTT,
1);
DetectBufferTypeSetDescriptionByName(BUFFER_NAME, BUFFER_DESC);
g_buffer_id = DetectBufferTypeGetByName(BUFFER_NAME);
SCLogDebug("registering " BUFFER_NAME " rule option");
}
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