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117 lines
3.9 KiB
C
117 lines
3.9 KiB
C
/* Copyright (C) 2015-2019 Open Information Security Foundation
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*
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* You can copy, redistribute or modify this Program under the terms of
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* the GNU General Public License version 2 as published by the Free
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* Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* version 2 along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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/**
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* \file
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*
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* \author Pierre Chifflier <chifflier@wzdftpd.net>
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*
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* Set up of the "snmp.community" keyword to allow content
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* inspections on the decoded snmp community.
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*/
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#include "suricata-common.h"
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#include "conf.h"
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#include "detect.h"
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#include "detect-parse.h"
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#include "detect-engine.h"
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#include "detect-engine-mpm.h"
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#include "detect-engine-prefilter.h"
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#include "detect-engine-content-inspection.h"
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#include "detect-snmp-community.h"
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#include "app-layer-parser.h"
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#include "rust.h"
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static int DetectSNMPCommunitySetup(DetectEngineCtx *, Signature *,
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const char *);
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static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
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const DetectEngineTransforms *transforms,
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Flow *f, const uint8_t flow_flags,
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void *txv, const int list_id);
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#ifdef UNITTESTS
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static void DetectSNMPCommunityRegisterTests(void);
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#endif
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static int g_snmp_rust_id = 0;
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void DetectSNMPCommunityRegister(void)
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{
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sigmatch_table[DETECT_AL_SNMP_COMMUNITY].name = "snmp.community";
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sigmatch_table[DETECT_AL_SNMP_COMMUNITY].desc =
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"SNMP content modifier to match on the SNMP community";
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sigmatch_table[DETECT_AL_SNMP_COMMUNITY].Setup =
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DetectSNMPCommunitySetup;
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#ifdef UNITTESTS
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sigmatch_table[DETECT_AL_SNMP_COMMUNITY].RegisterTests = DetectSNMPCommunityRegisterTests;
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#endif
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sigmatch_table[DETECT_AL_SNMP_COMMUNITY].url = "/rules/snmp-keywords.html#snmp-community";
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sigmatch_table[DETECT_AL_SNMP_COMMUNITY].flags |= SIGMATCH_NOOPT|SIGMATCH_INFO_STICKY_BUFFER;
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/* register inspect engines */
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DetectAppLayerInspectEngineRegister2("snmp.community",
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ALPROTO_SNMP, SIG_FLAG_TOSERVER, 0,
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DetectEngineInspectBufferGeneric, GetData);
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DetectAppLayerMpmRegister2("snmp.community", SIG_FLAG_TOSERVER, 2,
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PrefilterGenericMpmRegister, GetData, ALPROTO_SNMP, 0);
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DetectAppLayerInspectEngineRegister2("snmp.community",
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ALPROTO_SNMP, SIG_FLAG_TOCLIENT, 0,
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DetectEngineInspectBufferGeneric, GetData);
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DetectAppLayerMpmRegister2("snmp.community", SIG_FLAG_TOCLIENT, 2,
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PrefilterGenericMpmRegister, GetData, ALPROTO_SNMP, 0);
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DetectBufferTypeSetDescriptionByName("snmp.community", "SNMP Community identifier");
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g_snmp_rust_id = DetectBufferTypeGetByName("snmp.community");
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}
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static int DetectSNMPCommunitySetup(DetectEngineCtx *de_ctx, Signature *s,
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const char *str)
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{
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if (DetectBufferSetActiveList(s, g_snmp_rust_id) < 0)
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return -1;
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if (DetectSignatureSetAppProto(s, ALPROTO_SNMP) != 0)
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return -1;
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return 0;
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}
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static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
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const DetectEngineTransforms *transforms, Flow *f,
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const uint8_t flow_flags, void *txv, const int list_id)
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{
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InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
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if (buffer->inspect == NULL) {
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uint32_t data_len = 0;
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const uint8_t *data = NULL;
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rs_snmp_tx_get_community(txv, &data, &data_len);
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if (data == NULL || data_len == 0) {
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return NULL;
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}
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InspectionBufferSetup(buffer, data, data_len);
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InspectionBufferApplyTransforms(buffer, transforms);
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}
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return buffer;
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}
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#ifdef UNITTESTS
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#include "tests/detect-snmp-community.c"
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#endif /* UNITTESTS */
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