suricata
detect-snmp-usm.c
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1 /* Copyright (C) 2022 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 #include "suricata-common.h"
19 #include "rust.h"
20 #include "detect-snmp-usm.h"
21 #include "detect-engine.h"
22 #include "detect-engine-mpm.h"
24 #include "detect-parse.h"
25 
26 static int g_buffer_id = 0;
27 
28 static int DetectSNMPUsmSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
29 {
30  if (DetectBufferSetActiveList(s, g_buffer_id) < 0)
31  return -1;
32 
34  return -1;
35 
36  return 0;
37 }
38 
39 static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
40  const DetectEngineTransforms *transforms, Flow *f, const uint8_t flow_flags, void *txv,
41  const int list_id)
42 {
43  InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
44  if (buffer->inspect == NULL) {
45  uint32_t data_len = 0;
46  const uint8_t *data = NULL;
47 
48  rs_snmp_tx_get_usm(txv, &data, &data_len);
49  if (data == NULL || data_len == 0) {
50  return NULL;
51  }
52 
53  InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
54  InspectionBufferApplyTransforms(buffer, transforms);
55  }
56 
57  return buffer;
58 }
59 
61 {
63  sigmatch_table[DETECT_AL_SNMP_USM].desc = "SNMP content modifier to match on the SNMP usm";
64  sigmatch_table[DETECT_AL_SNMP_USM].Setup = DetectSNMPUsmSetup;
65 
67 
68  /* register inspect engines */
72  GetData, ALPROTO_SNMP, 0);
76  GetData, ALPROTO_SNMP, 0);
77 
78  DetectBufferTypeSetDescriptionByName("snmp.usm", "SNMP USM");
79 
80  g_buffer_id = DetectBufferTypeGetByName("snmp.usm");
81 }
DetectSignatureSetAppProto
int DetectSignatureSetAppProto(Signature *s, AppProto alproto)
Definition: detect-parse.c:1498
detect-engine.h
SIGMATCH_INFO_STICKY_BUFFER
#define SIGMATCH_INFO_STICKY_BUFFER
Definition: detect.h:1447
SigTableElmt_::desc
const char * desc
Definition: detect.h:1240
DetectEngineInspectBufferGeneric
uint8_t 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:1991
SigTableElmt_::name
const char * name
Definition: detect.h:1238
DetectEngineTransforms
Definition: detect.h:372
InspectionBuffer
Definition: detect.h:337
Flow_
Flow data structure.
Definition: flow.h:357
PrefilterGenericMpmRegister
int PrefilterGenericMpmRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx, const DetectBufferMpmRegistery *mpm_reg, int list_id)
Definition: detect-engine-prefilter.c:749
SigTableElmt_::flags
uint16_t flags
Definition: detect.h:1232
DetectEngineCtx_
main detection engine ctx
Definition: detect.h:785
rust.h
SIG_FLAG_TOCLIENT
#define SIG_FLAG_TOCLIENT
Definition: detect.h:229
SigTableElmt_::Setup
int(* Setup)(DetectEngineCtx *, Signature *, const char *)
Definition: detect.h:1223
detect-engine-prefilter.h
InspectionBufferGet
InspectionBuffer * InspectionBufferGet(DetectEngineThreadCtx *det_ctx, const int list_id)
Definition: detect-engine.c:1364
DetectBufferTypeGetByName
int DetectBufferTypeGetByName(const char *name)
Definition: detect-engine.c:1079
DETECT_AL_SNMP_USM
@ DETECT_AL_SNMP_USM
Definition: detect-engine-register.h:284
ALPROTO_SNMP
@ ALPROTO_SNMP
Definition: app-layer-protos.h:53
SIG_FLAG_TOSERVER
#define SIG_FLAG_TOSERVER
Definition: detect.h:228
de_ctx
DetectEngineCtx * de_ctx
Definition: fuzz_siginit.c:17
DetectEngineThreadCtx_
Definition: detect.h:1025
detect-engine-mpm.h
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:224
detect-snmp-usm.h
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
InspectionBufferApplyTransforms
void InspectionBufferApplyTransforms(InspectionBuffer *buffer, const DetectEngineTransforms *transforms)
Definition: detect-engine.c:1550
sigmatch_table
SigTableElmt sigmatch_table[DETECT_TBLSIZE]
Definition: detect-parse.c:76
InspectionBuffer::inspect
const uint8_t * inspect
Definition: detect.h:338
str
#define str(s)
Definition: suricata-common.h:280
InspectionBufferSetup
void InspectionBufferSetup(DetectEngineThreadCtx *det_ctx, const int list_id, InspectionBuffer *buffer, const uint8_t *data, const uint32_t data_len)
setup the buffer with our initial data
Definition: detect-engine.c:1446
detect-parse.h
Signature_
Signature container.
Definition: detect.h:540
DetectSNMPUsmRegister
void DetectSNMPUsmRegister(void)
Definition: detect-snmp-usm.c:60
SIGMATCH_NOOPT
#define SIGMATCH_NOOPT
Definition: detect.h:1423
DetectBufferSetActiveList
int DetectBufferSetActiveList(Signature *s, const int list)
Definition: detect-engine.c:1293
DetectBufferTypeSetDescriptionByName
void DetectBufferTypeSetDescriptionByName(const char *name, const char *desc)
Definition: detect-engine.c:1176