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/* Copyright (C) 2022 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 "rust.h"
#include "detect-snmp-usm.h"
#include "detect-engine.h"
#include "detect-engine-mpm.h"
#include "detect-engine-prefilter.h"
#include "detect-parse.h"
static int g_buffer_id = 0;
static int DetectSNMPUsmSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
if (DetectBufferSetActiveList(de_ctx, s, g_buffer_id) < 0)
return -1;
if (DetectSignatureSetAppProto(s, ALPROTO_SNMP) != 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) {
uint32_t data_len = 0;
const uint8_t *data = NULL;
rs_snmp_tx_get_usm(txv, &data, &data_len);
if (data == NULL || data_len == 0) {
return NULL;
}
InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
InspectionBufferApplyTransforms(buffer, transforms);
}
return buffer;
}
void DetectSNMPUsmRegister(void)
{
sigmatch_table[DETECT_AL_SNMP_USM].name = "snmp.usm";
sigmatch_table[DETECT_AL_SNMP_USM].desc = "SNMP content modifier to match on the SNMP usm";
sigmatch_table[DETECT_AL_SNMP_USM].Setup = DetectSNMPUsmSetup;
sigmatch_table[DETECT_AL_SNMP_USM].flags |= SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER;
/* register inspect engines */
DetectAppLayerInspectEngineRegister2("snmp.usm", ALPROTO_SNMP, SIG_FLAG_TOSERVER, 0,
DetectEngineInspectBufferGeneric, GetData);
DetectAppLayerMpmRegister2("snmp.usm", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
GetData, ALPROTO_SNMP, 0);
DetectAppLayerInspectEngineRegister2("snmp.usm", ALPROTO_SNMP, SIG_FLAG_TOCLIENT, 0,
DetectEngineInspectBufferGeneric, GetData);
DetectAppLayerMpmRegister2("snmp.usm", SIG_FLAG_TOCLIENT, 2, PrefilterGenericMpmRegister,
GetData, ALPROTO_SNMP, 0);
DetectBufferTypeSetDescriptionByName("snmp.usm", "SNMP USM");
g_buffer_id = DetectBufferTypeGetByName("snmp.usm");
}
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