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Cleanup bytetest and bytejump.

Browse Source
remotes/origin/master-1.0.x
Brian Rectanus 16 years ago committed by Victor Julien
parent a4fe971897
commit 3e9223c22c
4 changed files with 142 additions and 53 deletions
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130
src/detect-bytejump.c
Unescape Escape View File

@ -16,11 +16,8 @@
/**
* \brief Regex for parsing our options
*/
/** \todo We probably just need a simple tokenizer here */
/** \todo Cannot have > 9 captures and we need 10 -- write a comma separated value tokenizer for this. */
#define PARSE_REGEX "^\\s*" \
"([^\\s,]+)" \
"\\s*,\\s*([^\\s,]+)" \
"([^\\s,]+\\s*,\\s*[^\\s,]+)" \
"(?:\\s*,\\s*((?:multiplier|post_offset)\\s+[^\\s,]+|[^\\s,]+))?" \
"(?:\\s*,\\s*((?:multiplier|post_offset)\\s+[^\\s,]+|[^\\s,]+))?" \
"(?:\\s*,\\s*((?:multiplier|post_offset)\\s+[^\\s,]+|[^\\s,]+))?" \
@ -50,7 +47,8 @@ void DetectBytejumpRegister (void) {
parse_regex = pcre_compile(PARSE_REGEX, opts, &eb, &eo, NULL);
if(parse_regex == NULL)
{
printf("DetectBytejumpRegister: pcre compile of \"%s\" failed at offset %" PRId32 ": %s\n", PARSE_REGEX, eo, eb);
printf("DetectBytejumpRegister: pcre compile of \"%s\" failed "
"at offset %" PRId32 ": %s\n", PARSE_REGEX, eo, eb);
goto error;
}
@ -67,7 +65,8 @@ error:
return;
}
int DetectBytejumpMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p, Signature *s, SigMatch *m)
int DetectBytejumpMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx,
Packet *p, Signature *s, SigMatch *m)
{
DetectBytejumpData *data = (DetectBytejumpData *)m->ctx;
uint8_t *ptr = NULL;
@ -102,15 +101,19 @@ int DetectBytejumpMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p
/* Verify the to-be-extracted data is within the packet */
if ((ptr < p->pkt) || (len < 0) || (data->nbytes > len)) {
printf("DetectBytejumpMatch: Data not within packet pkt=%p, ptr=%p, len=%d, nbytes=%d\n", p->pkt, ptr, len, data->nbytes);
printf("DetectBytejumpMatch: Data not within packet "
"pkt=%p, ptr=%p, len=%d, nbytes=%d\n",
p->pkt, ptr, len, data->nbytes);
return 0;
}
/* Extract the byte data */
if (data->flags & DETECT_BYTEJUMP_STRING) {
extbytes = ByteExtractStringUint64(&val, data->base, data->nbytes, (const char *)ptr);
extbytes = ByteExtractStringUint64(&val, data->base,
data->nbytes, (const char *)ptr);
if(extbytes <= 0) {
printf("DetectBytejumpMatch: Error extracting %d bytes of string data: %d\n", data->nbytes, extbytes);
printf("DetectBytejumpMatch: Error extracting %d bytes "
"of string data: %d\n", data->nbytes, extbytes);
return -1;
}
}
@ -118,7 +121,8 @@ int DetectBytejumpMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p
int endianness = (data->flags & DETECT_BYTEJUMP_LITTLE) ? BYTE_LITTLE_ENDIAN : BYTE_BIG_ENDIAN;
extbytes = ByteExtractUint64(&val, endianness, data->nbytes, ptr);
if (extbytes != data->nbytes) {
printf("DetectBytejumpMatch: Error extracting %d bytes of numeric data: %d\n", data->nbytes, extbytes);
printf("DetectBytejumpMatch: Error extracting %d bytes "
"of numeric data: %d\n", data->nbytes, extbytes);
return -1;
}
}
@ -149,14 +153,19 @@ int DetectBytejumpMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p
* \todo Should this validate it is still in the *payload*?
*/
if ((jumpptr < p->pkt) || (jumpptr >= p->pkt + p->pktlen)) {
printf("DetectBytejumpMatch: Jump location (%p) is not within packet (%p-%p)\n", jumpptr, p->pkt, p->pkt + p->pktlen - 1);
printf("DetectBytejumpMatch: Jump location (%p) is not within "
"packet (%p-%p)\n", jumpptr, p->pkt, p->pkt + p->pktlen - 1);
return 0;
}
#ifdef DEBUG
{
uint8_t *sptr = (data->flags & DETECT_BYTEJUMP_BEGIN) ? p->payload : ptr;
printf("DetectBytejumpMatch: Jumping %" PRId64 " bytes from %p (%08x) to %p (%08x)\n", val, sptr, (int)(sptr - p->payload), jumpptr, (int)(jumpptr - p->payload));
uint8_t *sptr = (data->flags & DETECT_BYTEJUMP_BEGIN) ? p->payload
: ptr;
printf("DetectBytejumpMatch: Jumping %" PRId64 " bytes "
"from %p (%08x) to %p (%08x)\n",
val, sptr, (int)(sptr - p->payload),
jumpptr, (int)(jumpptr - p->payload));
}
#endif /* DEBUG */
@ -177,23 +186,62 @@ DetectBytejumpData *DetectBytejumpParse(char *optstr)
#define MAX_SUBSTRINGS 30
int ret = 0, res = 0;
int ov[MAX_SUBSTRINGS];
int i;
int numargs = 0;
int i = 0;
uint32_t nbytes;
const char *str_ptr;
char *str_ptr;
char *end_ptr;
/* Execute the regex and populate args with captures. */
ret = pcre_exec(parse_regex, parse_regex_study, optstr, strlen(optstr), 0, 0, ov, MAX_SUBSTRINGS);
ret = pcre_exec(parse_regex, parse_regex_study, optstr,
strlen(optstr), 0, 0, ov, MAX_SUBSTRINGS);
if (ret < 2 || ret > 10) {
printf("DetectBytejumpParse: parse error, ret %" PRId32 ", string \"%s\"\n", ret, optstr);
printf("DetectBytejumpParse: parse error, ret %" PRId32
", string \"%s\"\n", ret, optstr);
goto error;
}
for (i = 0; i < (ret - 1); i++) {
res = pcre_get_substring((char *)optstr, ov, MAX_SUBSTRINGS, i + 1, &str_ptr);
/* The first two arguments are stashed in the first PCRE substring.
* This is because byte_jump can take 10 arguments, but PCRE only
* supports 9 substrings, sigh.
*/
res = pcre_get_substring((char *)optstr, ov,
MAX_SUBSTRINGS, i + 1, (const char **)&str_ptr);
if (res < 0) {
printf("DetectBytejumpParse: pcre_get_substring failed "
"for arg %d\n", i + 1);
goto error;
}
/* Break up first substring into two parameters
*
* NOTE: Because of this, we cannot free args[1] as it is part of args[0],
* and *yes* this *is* ugly.
*/
end_ptr = str_ptr;
while (!(isspace(*end_ptr) || (*end_ptr == ','))) end_ptr++;
*(end_ptr++) = '\0';
args[0] = str_ptr;
numargs++;
str_ptr = end_ptr;
while (isspace(*str_ptr) || (*str_ptr == ',')) str_ptr++;
end_ptr = str_ptr;
while (!(isspace(*end_ptr) || (*end_ptr == ',')) && (*end_ptr != '\0'))
end_ptr++;
*(end_ptr++) = '\0';
args[1] = str_ptr;
numargs++;
/* The remaining args are directly from PCRE substrings */
for (i = 1; i < (ret - 1); i++) {
res = pcre_get_substring((char *)optstr, ov, MAX_SUBSTRINGS, i + 1, (const char **)&str_ptr);
if (res < 0) {
printf("DetectBytejumpParse: pcre_get_substring failed for arg %d\n", i + 1);
goto error;
}
args[i] = (char *)str_ptr;
args[i+1] = str_ptr;
numargs++;
}
/* Initialize the data */
@ -227,7 +275,7 @@ DetectBytejumpData *DetectBytejumpParse(char *optstr)
/* The remaining options are flags. */
/** \todo Error on dups? */
for (i = 2; i < (ret - 1); i++) {
for (i = 2; i < numargs; i++) {
if (strcmp("relative", args[i]) == 0) {
data->flags |= DETECT_BYTEJUMP_RELATIVE;
} else if (strcasecmp("string", args[i]) == 0) {
@ -249,12 +297,18 @@ DetectBytejumpData *DetectBytejumpParse(char *optstr)
} else if (strcasecmp("align", args[i]) == 0) {
data->flags |= DETECT_BYTEJUMP_ALIGN;
} else if (strncasecmp("multiplier ", args[i], 11) == 0) {
if (ByteExtractStringUint32(&data->multiplier, 10, strlen(args[i]) - 11, args[i] + 11) <= 0) {
if (ByteExtractStringUint32(&data->multiplier, 10,
strlen(args[i]) - 11,
args[i] + 11) <= 0)
{
printf("DetectBytejumpParse: Malformed multiplier: %s\n", optstr);
goto error;
}
} else if (strncasecmp("post_offset ", args[i], 12) == 0) {
if (ByteExtractStringInt32(&data->post_offset, 10, strlen(args[i]) - 12, args[i] + 12) <= 0) {
if (ByteExtractStringInt32(&data->post_offset, 10,
strlen(args[i]) - 12,
args[i] + 12) <= 0)
{
printf("DetectBytejumpParse: Malformed post_offset: %s\n", optstr);
goto error;
}
@ -273,16 +327,19 @@ DetectBytejumpData *DetectBytejumpParse(char *optstr)
* "01777777777777777777777" = 0xffffffffffffffff
*/
if (nbytes > 23) {
printf("DetectBytejumpParse: Cannot test more than 23 bytes with \"string\": %s\n", optstr);
printf("DetectBytejumpParse: Cannot test more than 23 bytes "
"with \"string\": %s\n", optstr);
goto error;
}
} else {
if (nbytes > 8) {
printf("DetectBytejumpParse: Cannot test more than 8 bytes without \"string\": %s\n", optstr);
printf("DetectBytejumpParse: Cannot test more than 8 bytes "
"without \"string\": %s\n", optstr);
goto error;
}
if (data->base != DETECT_BYTEJUMP_BASE_UNSET) {
printf("DetectBytejumpParse: Cannot use a base without \"string\": %s\n", optstr);
printf("DetectBytejumpParse: Cannot use a base "
"without \"string\": %s\n", optstr);
goto error;
}
}
@ -290,20 +347,23 @@ DetectBytejumpData *DetectBytejumpParse(char *optstr)
/* This is max 23 so it will fit in a byte (see above) */
data->nbytes = (uint8_t)nbytes;
for (i = 0; i < (ret - 1); i++){
for (i = 0; i < numargs; i++){
if (i == 1) continue; /* args[1] is part of args[0] */
if (args[i] != NULL) free(args[i]);
}
return data;
error:
for (i = 0; i < (ret - 1); i++){
for (i = 0; i < numargs; i++){
if (i == 1) continue; /* args[1] is part of args[0] */
if (args[i] != NULL) free(args[i]);
}
if (data != NULL) DetectBytejumpFree(data);
return NULL;
}
int DetectBytejumpSetup(DetectEngineCtx *de_ctx, Signature *s, SigMatch *m, char *optstr)
int DetectBytejumpSetup(DetectEngineCtx *de_ctx, Signature *s,
SigMatch *m, char *optstr)
{
DetectBytejumpData *data = NULL;
SigMatch *sm = NULL;
@ -390,7 +450,8 @@ int DetectBytejumpTestParse02(void) {
int DetectBytejumpTestParse03(void) {
int result = 0;
DetectBytejumpData *data = NULL;
data = DetectBytejumpParse(" 4,0 , relative , little, string, dec, align, from_beginning");
data = DetectBytejumpParse(" 4,0 , relative , little, string, "
"dec, align, from_beginning");
if (data != NULL) {
if ( (data->nbytes == 4)
&& (data->offset == 0)
@ -420,12 +481,14 @@ int DetectBytejumpTestParse03(void) {
int DetectBytejumpTestParse04(void) {
int result = 0;
DetectBytejumpData *data = NULL;
data = DetectBytejumpParse(" 4,0 , relative , little, string, dec, align, from_beginning , multiplier 2 , post_offset -16 ");
data = DetectBytejumpParse(" 4,0 , relative , little, string, "
"dec, align, from_beginning , "
"multiplier 2 , post_offset -16 ");
if (data != NULL) {
if ( (data->nbytes == 4)
&& (data->offset == 0)
&& (data->multiplier == 2)
&& (data->post_offset == 0)
&& (data->post_offset == -16)
&& (data->flags == ( DETECT_BYTEJUMP_RELATIVE
|DETECT_BYTEJUMP_LITTLE
|DETECT_BYTEJUMP_ALIGN
@ -447,7 +510,8 @@ int DetectBytejumpTestParse04(void) {
int DetectBytejumpTestParse05(void) {
int result = 0;
DetectBytejumpData *data = NULL;
data = DetectBytejumpParse(" 4,0 , relative , little, dec, align, from_beginning");
data = DetectBytejumpParse(" 4,0 , relative , little, dec, "
"align, from_beginning");
if (data == NULL) {
result = 1;
}

11
src/detect-bytejump.h
Unescape Escape View File

@ -49,7 +49,8 @@ void DetectBytejumpRegister (void);
* \retval 0 on Success
* \retval -1 on Failure
*/
int DetectBytejumpSetup(DetectEngineCtx *de_ctx, Signature *s, SigMatch *m, char *optstr);
int DetectBytejumpSetup(DetectEngineCtx *de_ctx, Signature *s,
SigMatch *m, char *optstr);
/**
* \brief this function will free memory associated with DetectBytejumpData
@ -85,9 +86,13 @@ DetectBytejumpData *DetectBytejumpParse(char *optstr);
* \retval 0 no match
* \retval 1 match
*
* \todo The return seems backwards. We should return a non-zero error code. One of the error codes is "no match". As-is if someone accidentally does: if (DetectBytejumpMatch(...)) { match }, then they catch an error as a match.
* \todo The return seems backwards. We should return a non-zero error code.
* One of the error codes is "no match". As-is if someone accidentally
* does: if (DetectBytejumpMatch(...)) { match }, then they catch an
* error as a match.
*/
int DetectBytejumpMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p, Signature *s, SigMatch *m);
int DetectBytejumpMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx,
Packet *p, Signature *s, SigMatch *m);
#endif /* __DETECT_BYTEJUMP_H__ */

48
src/detect-bytetest.c
Unescape Escape View File

@ -64,7 +64,8 @@ error:
return;
}
int DetectBytetestMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p, Signature *s, SigMatch *m)
int DetectBytetestMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx,
Packet *p, Signature *s, SigMatch *m)
{
DetectBytetestData *data = (DetectBytetestData *)m->ctx;
uint8_t *ptr = NULL;
@ -102,7 +103,9 @@ int DetectBytetestMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p
* \todo Should this validate it is in the *payload*?
*/
if ((ptr < p->pkt) || (len < 0) || (data->nbytes > len)) {
printf("DetectBytetestMatch: Data not within packet pkt=%p, ptr=%p, len=%d, nbytes=%d\n", p->pkt, ptr, len, data->nbytes);
printf("DetectBytetestMatch: Data not within packet "
"pkt=%p, ptr=%p, len=%d, nbytes=%d\n",
p->pkt, ptr, len, data->nbytes);
return 0;
}
@ -110,25 +113,32 @@ int DetectBytetestMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p
/* Extract the byte data */
if (data->flags & DETECT_BYTETEST_STRING) {
extbytes = ByteExtractStringUint64(&val, data->base, data->nbytes, (const char *)ptr);
extbytes = ByteExtractStringUint64(&val, data->base,
data->nbytes, (const char *)ptr);
if(extbytes <= 0) {
printf("DetectBytetestMatch: Error extracting %d bytes of string data: %d\n", data->nbytes, extbytes);
printf("DetectBytetestMatch: Error extracting %d "
"bytes of string data: %d\n", data->nbytes, extbytes);
return -1;
}
#ifdef DEBUG
printf("DetectBytetestMatch: Comparing base %d string 0x%" PRIx64 " %s%c 0x%" PRIx64 "\n", data->base, val, (neg ? "!" : ""), data->op, data->value);
printf("DetectBytetestMatch: Comparing base %d "
"string 0x%" PRIx64 " %s%c 0x%" PRIx64 "\n",
data->base, val, (neg ? "!" : ""), data->op, data->value);
#endif /* DEBUG */
}
else {
int endianness = (data->flags & DETECT_BYTETEST_LITTLE) ? BYTE_LITTLE_ENDIAN : BYTE_BIG_ENDIAN;
extbytes = ByteExtractUint64(&val, endianness, data->nbytes, ptr);
if (extbytes != data->nbytes) {
printf("DetectBytetestMatch: Error extracting %d bytes of numeric data: %d\n", data->nbytes, extbytes);
printf("DetectBytetestMatch: Error extracting %d bytes "
"of numeric data: %d\n", data->nbytes, extbytes);
return -1;
}
#ifdef DEBUG
printf("DetectBytetestMatch: Comparing numeric 0x%" PRIx64 " %s%c 0x%" PRIx64 "\n", val, (neg ? "!" : ""), data->op, data->value);
printf("DetectBytetestMatch: Comparing numeric 0x%" PRIx64
" %s%c 0x%" PRIx64 "\n",
val, (neg ? "!" : ""), data->op, data->value);
#endif /* DEBUG */
}
@ -195,15 +205,19 @@ DetectBytetestData *DetectBytetestParse(char *optstr)
const char *str_ptr;
/* Execute the regex and populate args with captures. */
ret = pcre_exec(parse_regex, parse_regex_study, optstr, strlen(optstr), 0, 0, ov, MAX_SUBSTRINGS);
ret = pcre_exec(parse_regex, parse_regex_study, optstr,
strlen(optstr), 0, 0, ov, MAX_SUBSTRINGS);
if (ret < 6 || ret > 10) {
printf("DetectBytetestParse: parse error, ret %" PRId32 ", string %s\n", ret, optstr);
printf("DetectBytetestParse: parse error, ret %" PRId32
", string %s\n", ret, optstr);
goto error;
}
for (i = 0; i < (ret - 1); i++) {
res = pcre_get_substring((char *)optstr, ov, MAX_SUBSTRINGS, i + 1, &str_ptr);
res = pcre_get_substring((char *)optstr, ov, MAX_SUBSTRINGS,
i + 1, &str_ptr);
if (res < 0) {
printf("DetectBytetestParse: pcre_get_substring failed for arg %d\n", i + 1);
printf("DetectBytetestParse: pcre_get_substring failed "
"for arg %d\n", i + 1);
goto error;
}
args[i] = (char *)str_ptr;
@ -297,16 +311,19 @@ DetectBytetestData *DetectBytetestParse(char *optstr)
* "01777777777777777777777" = 0xffffffffffffffff
*/
if (nbytes > 23) {
printf("DetectBytetestParse: Cannot test more than 23 bytes with \"string\": %s\n", optstr);
printf("DetectBytetestParse: Cannot test more than "
"23 bytes with \"string\": %s\n", optstr);
goto error;
}
} else {
if (nbytes > 8) {
printf("DetectBytetestParse: Cannot test more than 8 bytes without \"string\": %s\n", optstr);
printf("DetectBytetestParse: Cannot test more than "
"8 bytes without \"string\": %s\n", optstr);
goto error;
}
if (data->base != DETECT_BYTETEST_BASE_UNSET) {
printf("DetectBytetestParse: Cannot use a base without \"string\": %s\n", optstr);
printf("DetectBytetestParse: Cannot use a base "
"without \"string\": %s\n", optstr);
goto error;
}
}
@ -327,7 +344,8 @@ error:
return NULL;
}
int DetectBytetestSetup(DetectEngineCtx *de_ctx, Signature *s, SigMatch *m, char *optstr)
int DetectBytetestSetup(DetectEngineCtx *de_ctx, Signature *s,
SigMatch *m, char *optstr)
{
DetectBytetestData *data = NULL;
SigMatch *sm = NULL;

6
src/detect-bytetest.h
Unescape Escape View File

@ -55,7 +55,8 @@ void DetectBytetestRegister (void);
* \retval 0 on Success
* \retval -1 on Failure
*/
int DetectBytetestSetup(DetectEngineCtx *de_ctx, Signature *s, SigMatch *m, char *optstr);
int DetectBytetestSetup(DetectEngineCtx *de_ctx, Signature *s,
SigMatch *m, char *optstr);
/**
* \brief this function will free memory associated with DetectBytetestData
@ -92,7 +93,8 @@ DetectBytetestData *DetectBytetestParse(char *optstr);
*
* \todo The return seems backwards. We should return a non-zero error code. One of the error codes is "no match". As-is if someone accidentally does: if (DetectBytetestMatch(...)) { match }, then they catch an error as a match.
*/
int DetectBytetestMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p, Signature *s, SigMatch *m);
int DetectBytetestMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx,
Packet *p, Signature *s, SigMatch *m);
#endif /* __DETECT_BYTETEST_H__ */

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