suricata
detect-mqtt-connect-willtopic.c
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1 /* Copyright (C) 2020 Open Information Security Foundation
2  *
3  * You can copy, redistribute or modify this Program under the terms of
4  * the GNU General Public License version 2 as published by the Free
5  * Software Foundation.
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10  * GNU General Public License for more details.
11  *
12  * You should have received a copy of the GNU General Public License
13  * version 2 along with this program; if not, write to the Free Software
14  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
15  * 02110-1301, USA.
16  */
17 
18 /**
19  *
20  * \author Sascha Steinbiss <sascha@steinbiss.name>
21  *
22  * Implements the mqtt.connect.willtopic sticky buffer
23  */
24 
25 #include "suricata-common.h"
26 #include "detect.h"
27 #include "detect-parse.h"
28 #include "detect-engine.h"
29 #include "detect-engine-mpm.h"
32 #include "rust.h"
33 
34 #define KEYWORD_NAME "mqtt.connect.willtopic"
35 #define KEYWORD_DOC "mqtt-keywords.html#mqtt-connect-willtopic"
36 #define BUFFER_NAME "mqtt.connect.willtopic"
37 #define BUFFER_DESC "MQTT CONNECT will topic"
38 static int g_buffer_id = 0;
39 
40 static int DetectMQTTConnectWillTopicSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg)
41 {
42  if (DetectBufferSetActiveList(s, g_buffer_id) < 0)
43  return -1;
44 
46  return -1;
47 
48  return 0;
49 }
50 
51 static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
52  const DetectEngineTransforms *transforms,
53  Flow *_f, const uint8_t _flow_flags,
54  void *txv, const int list_id)
55 {
56  InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
57  if (buffer->inspect == NULL) {
58  const uint8_t *b = NULL;
59  uint32_t b_len = 0;
60 
61  if (rs_mqtt_tx_get_connect_willtopic(txv, &b, &b_len) != 1)
62  return NULL;
63  if (b == NULL || b_len == 0)
64  return NULL;
65 
66  InspectionBufferSetup(buffer, b, b_len);
67  InspectionBufferApplyTransforms(buffer, transforms);
68  }
69  return buffer;
70 }
71 
73 {
74  /* mqtt.connect.willtopic sticky buffer */
76  sigmatch_table[DETECT_AL_MQTT_CONNECT_WILLTOPIC].desc = "sticky buffer to match on the MQTT CONNECT will topic";
78  sigmatch_table[DETECT_AL_MQTT_CONNECT_WILLTOPIC].Setup = DetectMQTTConnectWillTopicSetup;
80 
84 
87  1);
88 
90 
92 
93  SCLogDebug("registering " BUFFER_NAME " rule option");
94 }
SigTableElmt_::url
const char * url
Definition: detect.h:1214
DetectSignatureSetAppProto
int DetectSignatureSetAppProto(Signature *s, AppProto alproto)
Definition: detect-parse.c:1480
BUFFER_DESC
#define BUFFER_DESC
Definition: detect-mqtt-connect-willtopic.c:37
detect-engine.h
SigTableElmt_::desc
const char * desc
Definition: detect.h:1213
SigTableElmt_::name
const char * name
Definition: detect.h:1211
DetectEngineTransforms
Definition: detect.h:376
SCLogDebug
#define SCLogDebug(...)
Definition: util-debug.h:298
InspectionBuffer
Definition: detect.h:344
Flow_
Flow data structure.
Definition: flow.h:347
PrefilterGenericMpmRegister
int PrefilterGenericMpmRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx, const DetectBufferMpmRegistery *mpm_reg, int list_id)
Definition: detect-engine-prefilter.c:611
SigTableElmt_::flags
uint16_t flags
Definition: detect.h:1205
DetectEngineCtx_
main detection engine ctx
Definition: detect.h:767
rust.h
SigTableElmt_::Setup
int(* Setup)(DetectEngineCtx *, Signature *, const char *)
Definition: detect.h:1196
detect-engine-prefilter.h
InspectionBufferGet
InspectionBuffer * InspectionBufferGet(DetectEngineThreadCtx *det_ctx, const int list_id)
Definition: detect-engine.c:1061
KEYWORD_NAME
#define KEYWORD_NAME
Definition: detect-mqtt-connect-willtopic.c:34
DetectBufferTypeGetByName
int DetectBufferTypeGetByName(const char *name)
Definition: detect-engine.c:880
SIG_FLAG_TOSERVER
#define SIG_FLAG_TOSERVER
Definition: detect.h:236
de_ctx
DetectEngineCtx * de_ctx
Definition: fuzz_siginit.c:17
DetectEngineThreadCtx_
Definition: detect.h:1010
detect-engine-mpm.h
detect.h
DetectEngineInspectBufferGeneric
int DetectEngineInspectBufferGeneric(DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, const DetectEngineAppInspectionEngine *engine, const Signature *s, Flow *f, uint8_t flags, void *alstate, void *txv, uint64_t tx_id)
Do the content inspection & validation for a signature.
Definition: detect-engine.c:1641
DetectAppLayerInspectEngineRegister2
void DetectAppLayerInspectEngineRegister2(const char *name, AppProto alproto, uint32_t dir, int progress, InspectEngineFuncPtr2 Callback2, InspectionBufferGetDataPtr GetData)
register inspect engine at start up time
Definition: detect-engine.c:232
DetectAppLayerMpmRegister2
void DetectAppLayerMpmRegister2(const char *name, int direction, int priority, int(*PrefilterRegister)(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx, const DetectBufferMpmRegistery *mpm_reg, int list_id), InspectionBufferGetDataPtr GetData, AppProto alproto, int tx_min_progress)
register a MPM engine
Definition: detect-engine-mpm.c:89
suricata-common.h
InspectionBufferSetup
void InspectionBufferSetup(InspectionBuffer *buffer, const uint8_t *data, const uint32_t data_len)
setup the buffer with our initial data
Definition: detect-engine.c:1120
InspectionBufferApplyTransforms
void InspectionBufferApplyTransforms(InspectionBuffer *buffer, const DetectEngineTransforms *transforms)
Definition: detect-engine.c:1211
sigmatch_table
SigTableElmt sigmatch_table[DETECT_TBLSIZE]
Definition: detect-parse.c:73
InspectionBuffer::inspect
const uint8_t * inspect
Definition: detect.h:345
KEYWORD_DOC
#define KEYWORD_DOC
Definition: detect-mqtt-connect-willtopic.c:35
detect-parse.h
Signature_
Signature container.
Definition: detect.h:528
detect-mqtt-connect-willtopic.h
ALPROTO_MQTT
@ ALPROTO_MQTT
Definition: app-layer-protos.h:55
BUFFER_NAME
#define BUFFER_NAME
Definition: detect-mqtt-connect-willtopic.c:36
DETECT_AL_MQTT_CONNECT_WILLTOPIC
@ DETECT_AL_MQTT_CONNECT_WILLTOPIC
Definition: detect-engine-register.h:279
SIGMATCH_NOOPT
#define SIGMATCH_NOOPT
Definition: detect.h:1380
DetectBufferSetActiveList
int DetectBufferSetActiveList(Signature *s, const int list)
Definition: detect-engine.c:992
DetectBufferTypeSetDescriptionByName
void DetectBufferTypeSetDescriptionByName(const char *name, const char *desc)
Definition: detect-engine.c:908
DetectMQTTConnectWillTopicRegister
void DetectMQTTConnectWillTopicRegister(void)
Definition: detect-mqtt-connect-willtopic.c:72