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detect: use generic integer functions for snmp.version

Browse Source 
Ticket: #4112
pull/7603/head
Philippe Antoine 2 years ago committed by Victor Julien
parent c72571ea28
commit 2817f1a6ed
2 changed files with 17 additions and 127 deletions
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136
src/detect-snmp-version.c
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@ -28,29 +28,11 @@
#include "detect-engine.h"
#include "detect-engine-content-inspection.h"
#include "detect-snmp-version.h"
#include "detect-engine-uint.h"
#include "app-layer-parser.h"
#include "rust.h"
/**
* [snmp.version]:[<|>|<=|>=]<version>;
*/
#define PARSE_REGEX "^\\s*(<=|>=|<|>)?\\s*([0-9]+)\\s*$"
static DetectParseRegex parse_regex;
enum DetectSNMPVersionMode {
PROCEDURE_EQ = 1, /* equal */
PROCEDURE_LT, /* less than */
PROCEDURE_LE, /* less than or equal */
PROCEDURE_GT, /* greater than */
PROCEDURE_GE, /* greater than or equal */
};
typedef struct DetectSNMPVersionData_ {
uint32_t version;
enum DetectSNMPVersionMode mode;
} DetectSNMPVersionData;
static DetectSNMPVersionData *DetectSNMPVersionParse (const char *);
static int DetectSNMPVersionSetup (DetectEngineCtx *, Signature *s, const char *str);
static void DetectSNMPVersionFree(DetectEngineCtx *, void *);
#ifdef UNITTESTS
@ -82,8 +64,6 @@ void DetectSNMPVersionRegister (void)
sigmatch_table[DETECT_AL_SNMP_VERSION].RegisterTests = DetectSNMPVersionRegisterTests;
#endif
DetectSetupParseRegexes(PARSE_REGEX, &parse_regex);
DetectAppLayerInspectEngineRegister2("snmp.version", ALPROTO_SNMP, SIG_FLAG_TOSERVER, 0,
DetectEngineInspectSNMPRequestGeneric, NULL);
@ -101,35 +81,6 @@ static uint8_t DetectEngineInspectSNMPRequestGeneric(DetectEngineCtx *de_ctx,
de_ctx, det_ctx, s, engine->smd, f, flags, alstate, txv, tx_id);
}
static inline int
VersionMatch(const uint32_t version,
enum DetectSNMPVersionMode mode, uint32_t ref_version)
{
switch (mode) {
case PROCEDURE_EQ:
if (version == ref_version)
SCReturnInt(1);
break;
case PROCEDURE_LT:
if (version < ref_version)
SCReturnInt(1);
break;
case PROCEDURE_LE:
if (version <= ref_version)
SCReturnInt(1);
break;
case PROCEDURE_GT:
if (version > ref_version)
SCReturnInt(1);
break;
case PROCEDURE_GE:
if (version >= ref_version)
SCReturnInt(1);
break;
}
SCReturnInt(0);
}
/**
* \internal
* \brief Function to match version of a TX
@ -141,7 +92,7 @@ VersionMatch(const uint32_t version,
* \param state App layer state.
* \param s Pointer to the Signature.
* \param m Pointer to the sigmatch that we will cast into
* DetectSNMPVersionData.
* DetectU32Data.
*
* \retval 0 no match.
* \retval 1 match.
@ -153,12 +104,11 @@ static int DetectSNMPVersionMatch (DetectEngineThreadCtx *det_ctx,
{
SCEnter();
const DetectSNMPVersionData *dd = (const DetectSNMPVersionData *)ctx;
const DetectU32Data *dd = (const DetectU32Data *)ctx;
uint32_t version;
rs_snmp_tx_get_version(txv, &version);
SCLogDebug("version %u mode %u ref_version %d",
version, dd->mode, dd->version);
if (VersionMatch(version, dd->mode, dd->version))
SCLogDebug("version %u mode %u ref_version %d", version, dd->mode, dd->arg1);
if (DetectU32Match(version, dd))
SCReturnInt(1);
SCReturnInt(0);
}
@ -169,72 +119,12 @@ static int DetectSNMPVersionMatch (DetectEngineThreadCtx *det_ctx,
*
* \param rawstr Pointer to the user provided options.
*
* \retval dd pointer to DetectSNMPVersionData on success.
* \retval dd pointer to DetectU32Data on success.
* \retval NULL on failure.
*/
static DetectSNMPVersionData *DetectSNMPVersionParse (const char *rawstr)
static DetectU32Data *DetectSNMPVersionParse(const char *rawstr)
{
DetectSNMPVersionData *dd = NULL;
int ret = 0, res = 0;
size_t pcre2len;
char mode[2] = "";
char value1[20] = "";
char *endptr = NULL;
ret = DetectParsePcreExec(&parse_regex, rawstr, 0, 0);
if (ret < 3 || ret > 5) {
SCLogError(SC_ERR_PCRE_MATCH, "Parse error %s", rawstr);
goto error;
}
pcre2len = sizeof(mode);
res = SC_Pcre2SubstringCopy(parse_regex.match, 1, (PCRE2_UCHAR8 *)mode, &pcre2len);
if (res < 0) {
SCLogError(SC_ERR_PCRE_GET_SUBSTRING, "pcre2_substring_copy_bynumber failed");
goto error;
}
pcre2len = sizeof(value1);
res = pcre2_substring_copy_bynumber(parse_regex.match, 2, (PCRE2_UCHAR8 *)value1, &pcre2len);
if (res < 0) {
SCLogError(SC_ERR_PCRE_GET_SUBSTRING, "pcre2_substring_copy_bynumber failed");
goto error;
}
dd = SCCalloc(1, sizeof(DetectSNMPVersionData));
if (unlikely(dd == NULL))
goto error;
if (strlen(mode) == 1) {
if (mode[0] == '<')
dd->mode = PROCEDURE_LT;
else if (mode[0] == '>')
dd->mode = PROCEDURE_GT;
} else if (strlen(mode) == 2) {
if (strcmp(mode, "<=") == 0)
dd->mode = PROCEDURE_LE;
if (strcmp(mode, ">=") == 0)
dd->mode = PROCEDURE_GE;
}
if (dd->mode == 0) {
dd->mode = PROCEDURE_EQ;
}
/* set the first value */
dd->version = strtoul(value1, &endptr, 10);
if (endptr == NULL || *endptr != '\0') {
SCLogError(SC_ERR_INVALID_SIGNATURE, "invalid character as arg "
"to snmp.version keyword");
goto error;
}
return dd;
error:
if (dd)
SCFree(dd);
return NULL;
return DetectU32Parse(rawstr);
}
@ -253,7 +143,7 @@ error:
static int DetectSNMPVersionSetup (DetectEngineCtx *de_ctx, Signature *s,
const char *rawstr)
{
DetectSNMPVersionData *dd = NULL;
DetectU32Data *dd = NULL;
SigMatch *sm = NULL;
if (DetectSignatureSetAppProto(s, ALPROTO_SNMP) != 0)
@ -274,7 +164,7 @@ static int DetectSNMPVersionSetup (DetectEngineCtx *de_ctx, Signature *s,
sm->type = DETECT_AL_SNMP_VERSION;
sm->ctx = (void *)dd;
SCLogDebug("snmp.version %d", dd->version);
SCLogDebug("snmp.version %d", dd->arg1);
SigMatchAppendSMToList(s, sm, g_snmp_version_buffer_id);
return 0;
@ -285,13 +175,13 @@ error:
/**
* \internal
* \brief Function to free memory associated with DetectSNMPVersionData.
* \brief Function to free memory associated with DetectU32Data.
*
* \param de_ptr Pointer to DetectSNMPVersionData.
* \param de_ptr Pointer to DetectU32Data.
*/
static void DetectSNMPVersionFree(DetectEngineCtx *de_ctx, void *ptr)
{
SCFree(ptr);
rs_detect_u32_free(ptr);
}

8
src/tests/detect-snmp-version.c
Unescape Escape View File

@ -26,10 +26,10 @@
*/
static int SNMPValidityTestParse01 (void)
{
DetectSNMPVersionData *dd = NULL;
DetectU32Data *dd = NULL;
dd = DetectSNMPVersionParse("2");
FAIL_IF_NULL(dd);
FAIL_IF_NOT(dd->version == 2 && dd->mode == PROCEDURE_EQ);
FAIL_IF_NOT(dd->arg1 == 2 && dd->mode == DETECT_UINT_EQ);
DetectSNMPVersionFree(NULL, dd);
PASS;
}
@ -42,10 +42,10 @@ static int SNMPValidityTestParse01 (void)
*/
static int SNMPValidityTestParse02 (void)
{
DetectSNMPVersionData *dd = NULL;
DetectU32Data *dd = NULL;
dd = DetectSNMPVersionParse(">2");
FAIL_IF_NULL(dd);
FAIL_IF_NOT(dd->version == 2 && dd->mode == PROCEDURE_GT);
FAIL_IF_NOT(dd->arg1 == 2 && dd->mode == DETECT_UINT_GT);
DetectSNMPVersionFree(NULL, dd);
PASS;
}

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