--- /dev/null
+/* Copyright (C) 2015-2019 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.
+ */
+
+/**
+ * \file
+ *
+ * \author Pierre Chifflier <chifflier@wzdftpd.net>
+ */
+
+#include "suricata-common.h"
+#include "conf.h"
+#include "detect.h"
+#include "detect-parse.h"
+#include "detect-engine.h"
+#include "detect-engine-content-inspection.h"
+#include "detect-snmp-pdu_type.h"
+#include "app-layer-parser.h"
+
+#ifndef HAVE_RUST
+
+void DetectSNMPPduTypeRegister(void)
+{
+}
+
+#else
+
+#include "rust-snmp-snmp-gen.h"
+#include "rust-snmp-detect-gen.h"
+
+/**
+ * [snmp_pdu_type]:<type>;
+ */
+#define PARSE_REGEX "^\\s*([0-9]+)\\s*$"
+static pcre *parse_regex;
+static pcre_extra *parse_regex_study;
+
+typedef struct DetectSNMPPduTypeData_ {
+ uint32_t pdu_type;
+} DetectSNMPPduTypeData;
+
+static DetectSNMPPduTypeData *DetectSNMPPduTypeParse (const char *);
+static int DetectSNMPPduTypeSetup (DetectEngineCtx *, Signature *s, const char *str);
+static void DetectSNMPPduTypeFree(void *);
+static void DetectSNMPPduTypeRegisterTests(void);
+static int g_snmp_pdu_type_buffer_id = 0;
+
+static int DetectEngineInspectSNMPRequestGeneric(ThreadVars *tv,
+ DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx,
+ const Signature *s, const SigMatchData *smd,
+ Flow *f, uint8_t flags, void *alstate,
+ void *txv, uint64_t tx_id);
+
+static int DetectSNMPPduTypeMatch (ThreadVars *, DetectEngineThreadCtx *, Flow *,
+ uint8_t, void *, void *, const Signature *,
+ const SigMatchCtx *);
+
+void DetectSNMPPduTypeRegister(void)
+{
+ sigmatch_table[DETECT_AL_SNMP_PDU_TYPE].name = "snmp_pdu_type";
+ sigmatch_table[DETECT_AL_SNMP_PDU_TYPE].desc = "match SNMP Pdu type";
+ sigmatch_table[DETECT_AL_SNMP_PDU_TYPE].url = DOC_URL DOC_VERSION "/rules/snmp-keywords.html#snmp_pdu_type";
+ sigmatch_table[DETECT_AL_SNMP_PDU_TYPE].Match = NULL;
+ sigmatch_table[DETECT_AL_SNMP_PDU_TYPE].AppLayerTxMatch = DetectSNMPPduTypeMatch;
+ sigmatch_table[DETECT_AL_SNMP_PDU_TYPE].Setup = DetectSNMPPduTypeSetup;
+ sigmatch_table[DETECT_AL_SNMP_PDU_TYPE].Free = DetectSNMPPduTypeFree;
+ sigmatch_table[DETECT_AL_SNMP_PDU_TYPE].RegisterTests = DetectSNMPPduTypeRegisterTests;
+
+ DetectSetupParseRegexes(PARSE_REGEX, &parse_regex, &parse_regex_study);
+
+ DetectAppLayerInspectEngineRegister("snmp_pdu_type",
+ ALPROTO_SNMP, SIG_FLAG_TOSERVER, 0,
+ DetectEngineInspectSNMPRequestGeneric);
+
+ DetectAppLayerInspectEngineRegister("snmp_pdu_type",
+ ALPROTO_SNMP, SIG_FLAG_TOCLIENT, 0,
+ DetectEngineInspectSNMPRequestGeneric);
+
+ g_snmp_pdu_type_buffer_id = DetectBufferTypeGetByName("snmp_pdu_type");
+
+ SCLogDebug("g_snmp_pdu_type_buffer_id %d", g_snmp_pdu_type_buffer_id);
+}
+
+static int DetectEngineInspectSNMPRequestGeneric(ThreadVars *tv,
+ DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx,
+ const Signature *s, const SigMatchData *smd,
+ Flow *f, uint8_t flags, void *alstate,
+ void *txv, uint64_t tx_id)
+{
+ return DetectEngineInspectGenericList(tv, de_ctx, det_ctx, s, smd,
+ f, flags, alstate, txv, tx_id);
+}
+
+/**
+ * \internal
+ * \brief Function to match pdu_type of a TX
+ *
+ * \param t Pointer to thread vars.
+ * \param det_ctx Pointer to the pattern matcher thread.
+ * \param f Pointer to the current flow.
+ * \param flags Flags.
+ * \param state App layer state.
+ * \param s Pointer to the Signature.
+ * \param m Pointer to the sigmatch that we will cast into
+ * DetectSNMPPduTypeData.
+ *
+ * \retval 0 no match.
+ * \retval 1 match.
+ */
+static int DetectSNMPPduTypeMatch (ThreadVars *t, DetectEngineThreadCtx *det_ctx,
+ Flow *f, uint8_t flags, void *state,
+ void *txv, const Signature *s,
+ const SigMatchCtx *ctx)
+{
+ SCEnter();
+
+ const DetectSNMPPduTypeData *dd = (const DetectSNMPPduTypeData *)ctx;
+ uint32_t pdu_type;
+ rs_snmp_tx_get_pdu_type(txv, &pdu_type);
+ SCLogDebug("pdu_type %u ref_pdu_type %d",
+ pdu_type, dd->pdu_type);
+ if (pdu_type == dd->pdu_type)
+ SCReturnInt(1);
+ SCReturnInt(0);
+}
+
+/**
+ * \internal
+ * \brief Function to parse options passed via snmp_pdu_type keywords.
+ *
+ * \param rawstr Pointer to the user provided options.
+ *
+ * \retval dd pointer to DetectSNMPPduTypeData on success.
+ * \retval NULL on failure.
+ */
+static DetectSNMPPduTypeData *DetectSNMPPduTypeParse (const char *rawstr)
+{
+ DetectSNMPPduTypeData *dd = NULL;
+#define MAX_SUBSTRINGS 30
+ int ret = 0, res = 0;
+ int ov[MAX_SUBSTRINGS];
+ char value1[20] = "";
+ char *endptr = NULL;
+
+ ret = pcre_exec(parse_regex, parse_regex_study, rawstr, strlen(rawstr), 0,
+ 0, ov, MAX_SUBSTRINGS);
+ if (ret != 2) {
+ SCLogError(SC_ERR_PCRE_MATCH, "Parse error %s", rawstr);
+ goto error;
+ }
+
+ res = pcre_copy_substring((char *)rawstr, ov, MAX_SUBSTRINGS, 1, value1,
+ sizeof(value1));
+ if (res < 0) {
+ SCLogError(SC_ERR_PCRE_GET_SUBSTRING, "pcre_copy_substring failed");
+ goto error;
+ }
+
+ dd = SCCalloc(1, sizeof(DetectSNMPPduTypeData));
+ if (unlikely(dd == NULL))
+ goto error;
+
+ /* set the value */
+ dd->pdu_type = strtoul(value1, &endptr, 10);
+ if (endptr == NULL || *endptr != '\0') {
+ SCLogError(SC_ERR_INVALID_SIGNATURE, "invalid character as arg "
+ "to snmp_pdu_type keyword");
+ goto error;
+ }
+
+ return dd;
+
+error:
+ if (dd)
+ SCFree(dd);
+ return NULL;
+}
+
+/**
+ * \brief Function to add the parsed snmp pdu_type field into the current signature.
+ *
+ * \param de_ctx Pointer to the Detection Engine Context.
+ * \param s Pointer to the Current Signature.
+ * \param rawstr Pointer to the user provided flags options.
+ * \param type Defines if this is notBefore or notAfter.
+ *
+ * \retval 0 on Success.
+ * \retval -1 on Failure.
+ */
+static int DetectSNMPPduTypeSetup (DetectEngineCtx *de_ctx, Signature *s,
+ const char *rawstr)
+{
+ DetectSNMPPduTypeData *dd = NULL;
+ SigMatch *sm = NULL;
+
+ if (DetectSignatureSetAppProto(s, ALPROTO_SNMP) != 0)
+ return -1;
+
+ dd = DetectSNMPPduTypeParse(rawstr);
+ if (dd == NULL) {
+ SCLogError(SC_ERR_INVALID_ARGUMENT,"Parsing \'%s\' failed", rawstr);
+ goto error;
+ }
+
+ /* okay so far so good, lets get this into a SigMatch
+ * and put it in the Signature. */
+ sm = SigMatchAlloc();
+ if (sm == NULL)
+ goto error;
+
+ sm->type = DETECT_AL_SNMP_PDU_TYPE;
+ sm->ctx = (void *)dd;
+
+ SCLogDebug("snmp_pdu_type %d", dd->pdu_type);
+ SigMatchAppendSMToList(s, sm, g_snmp_pdu_type_buffer_id);
+ return 0;
+
+error:
+ DetectSNMPPduTypeFree(dd);
+ return -1;
+}
+
+/**
+ * \internal
+ * \brief Function to free memory associated with DetectSNMPPduTypeData.
+ *
+ * \param de_ptr Pointer to DetectSNMPPduTypeData.
+ */
+static void DetectSNMPPduTypeFree(void *ptr)
+{
+ SCFree(ptr);
+}
+
+
+#ifdef UNITTESTS
+
+#include "util-unittest.h"
+#include "util-unittest-helper.h"
+
+/**
+ * \test This is a test for a valid value 2.
+ *
+ * \retval 1 on success.
+ * \retval 0 on failure.
+ */
+static int SNMPValidityTestParse01 (void)
+{
+ DetectSNMPPduTypeData *dd = NULL;
+ dd = DetectSNMPPduTypeParse("2");
+ FAIL_IF_NULL(dd);
+ FAIL_IF_NOT(dd->pdu_type == 2);
+ DetectSNMPPduTypeFree(dd);
+ PASS;
+}
+
+#endif
+
+static void DetectSNMPPduTypeRegisterTests(void)
+{
+#ifdef UNITTESTS
+ UtRegisterTest("SNMPValidityTestParse01", SNMPValidityTestParse01);
+#endif /* UNITTESTS */
+}
+
+#endif
projects / thirdparty / suricata.git / commitdiff
