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Bug #212 » 0002-fix-relative-contents-with-a-negated-content-for-det.patch

Anoop Saldanha, 07/16/2010 09:38 AM

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src/detect-engine-dcepayload.c
} else if (found == NULL && cd->flags & DETECT_CONTENT_NEGATED) {
goto match;
} else if (found != NULL && cd->flags & DETECT_CONTENT_NEGATED) {
match_offset = (uint32_t)((found - stub) + cd->content_len);
SCLogDebug("content %"PRIu32" matched at offset %"PRIu32", but "
"negated so no match", cd->id, match_offset);
det_ctx->discontinue_matching = 1;
SCReturnInt(0);
} else {
match_offset = (uint32_t)((found - stub) + cd->content_len);
......
SCReturnInt(1);
}
if (det_ctx->discontinue_matching)
SCReturnInt(0);
/* set the previous match offset to the start of this match + 1 */
prev_offset = (match_offset - (cd->content_len - 1));
SCLogDebug("trying to see if there is another match after "
......
}
det_ctx->payload_offset = 0;
det_ctx->discontinue_matching = 0;
r = DoInspectDcePayload(de_ctx, det_ctx, s, s->dmatch, f,
dce_stub_data, dce_stub_data_len, dcerpc_state);
......
return result;
}
/**
* \test Test the working of consecutive relative matches with a negated content.
*/
int DcePayloadTest42(void)
{
int result = 0;
uint8_t request1[] = {
0x05, 0x00, 0x00, 0x03, 0x10, 0x00, 0x00, 0x00,
0x68, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
0x50, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1a, 0x00,
0x77, 0x65, 0x20, 0x6e, 0x65, 0x65, 0x64, 0x20, /* "we need " */
0x74, 0x6f, 0x20, 0x66, 0x69, 0x78, 0x20, 0x74, /* "to fix t" */
0x68, 0x69, 0x73, 0x20, 0x61, 0x6e, 0x64, 0x20, /* "his and " */
0x79, 0x65, 0x73, 0x20, 0x66, 0x69, 0x78, 0x20, /* "yes fix " */
0x74, 0x68, 0x69, 0x73, 0x20, 0x6e, 0x6f, 0x77 /* "this now" */
};
uint32_t request1_len = sizeof(request1);
TcpSession ssn;
Packet p;
ThreadVars tv;
DetectEngineCtx *de_ctx = NULL;
DetectEngineThreadCtx *det_ctx = NULL;
Flow f;
int r;
char *sig1 = "alert tcp any any -> any any "
"(msg:\"testing dce consecutive relative matches\"; dce_stub_data; "
"content:fix; distance:0; content:this; within:6; "
"content:!\"and\"; distance:0; sid:1;)";
Signature *s;
memset(&tv, 0, sizeof(ThreadVars));
memset(&f, 0, sizeof(Flow));
memset(&ssn, 0, sizeof(TcpSession));
memset(&p, 0, sizeof(Packet));
p.src.family = AF_INET;
p.dst.family = AF_INET;
p.payload = NULL;
p.payload_len = 0;
p.proto = IPPROTO_TCP;
p.flow = &f;
p.flowflags |= FLOW_PKT_TOSERVER;
p.flowflags |= FLOW_PKT_ESTABLISHED;
FLOW_INITIALIZE(&f);
f.protoctx = (void *)&ssn;
f.src.family = AF_INET;
f.dst.family = AF_INET;
f.alproto = ALPROTO_DCERPC;
StreamTcpInitConfig(TRUE);
FlowL7DataPtrInit(&f);
de_ctx = DetectEngineCtxInit();
if (de_ctx == NULL)
goto end;
de_ctx->flags |= DE_QUIET;
de_ctx->sig_list = SigInit(de_ctx, sig1);
s = de_ctx->sig_list;
if (s == NULL)
goto end;
SigGroupBuild(de_ctx);
DetectEngineThreadCtxInit(&tv, (void *)de_ctx, (void *)&det_ctx);
/* request 1 */
r = AppLayerParse(&f, ALPROTO_DCERPC, STREAM_TOSERVER, request1, request1_len);
if (r != 0) {
printf("toserver chunk 1 returned %" PRId32 ", expected 0: ", r);
result = 0;
goto end;
}
/* detection phase */
SigMatchSignatures(&tv, de_ctx, det_ctx, &p);
if ((PacketAlertCheck(&p, 1))) {
printf("sid 1 matched but shouldn't have for packet: ");
goto end;
}
result = 1;
end:
if (de_ctx != NULL) {
SigGroupCleanup(de_ctx);
SigCleanSignatures(de_ctx);
DetectEngineThreadCtxDeinit(&tv, (void *)det_ctx);
DetectEngineCtxFree(de_ctx);
}
FlowL7DataPtrFree(&f);
StreamTcpFreeConfig(TRUE);
return result;
}
#endif /* UNITTESTS */
void DcePayloadRegisterTests(void)
......
UtRegisterTest("DcePayloadParseTest39", DcePayloadParseTest39, 1);
UtRegisterTest("DcePayloadParseTest40", DcePayloadParseTest40, 1);
UtRegisterTest("DcePayloadParseTest41", DcePayloadParseTest41, 1);
UtRegisterTest("DcePayloadTest42", DcePayloadTest42, 1);
#endif /* UNITTESTS */
return;
src/detect-engine-uri.c
} else if (found == NULL && ud->flags & DETECT_URICONTENT_NEGATED) {
goto match;
} else if (found != NULL && ud->flags & DETECT_URICONTENT_NEGATED) {
/* why are we saving match offset here? */
match_offset = (uint32_t)((found - payload) + ud->uricontent_len);
SCLogDebug("uricontent %"PRIu32" matched at offset %"PRIu32", but negated so no match", ud->id, match_offset);
det_ctx->discontinue_matching = 1;
SCReturnInt(0);
} else {
match_offset = (uint32_t)((found - payload) + ud->uricontent_len);
......
SCReturnInt(1);
}
if (det_ctx->discontinue_matching)
SCReturnInt(0);
/* set the previous match offset to the start of this match + 1 */
prev_offset = (match_offset - (ud->uricontent_len - 1));
SCLogDebug("trying to see if there is another match after prev_offset %"PRIu32, prev_offset);
......
if (tx == NULL || tx->request_uri_normalized == NULL)
continue;
det_ctx->discontinue_matching = 0;
/* Inspect all the uricontents fetched on each
* transaction at the app layer */
r = DoInspectPacketUri(de_ctx, det_ctx, s, s->umatch,
......
return result;
}
/**
* \test Test multiple relative contents with a negated content.
*/
static int UriTestSig21(void)
{
int result = 0;
uint8_t *http_buf = (uint8_t *)"POST /we_need_to_fix_this_and_yes_fix_this_now HTTP/1.0\r\n"
"User-Agent: Mozilla/1.0\r\n";
uint32_t http_buf_len = strlen((char *)http_buf);
Flow f;
TcpSession ssn;
HtpState *http_state = NULL;
Packet p;
ThreadVars tv;
DetectEngineThreadCtx *det_ctx = NULL;
memset(&tv, 0, sizeof(ThreadVars));
memset(&p, 0, sizeof(Packet));
memset(&f, 0, sizeof(Flow));
memset(&ssn, 0, sizeof(TcpSession));
p.src.family = AF_INET;
p.dst.family = AF_INET;
p.payload = http_buf;
p.payload_len = http_buf_len;
p.proto = IPPROTO_TCP;
FLOW_INITIALIZE(&f);
f.protoctx = (void *)&ssn;
f.src.family = AF_INET;
f.dst.family = AF_INET;
p.flow = &f;
p.flowflags |= FLOW_PKT_TOSERVER;
p.flowflags |= FLOW_PKT_ESTABLISHED;
f.alproto = ALPROTO_HTTP;
StreamTcpInitConfig(TRUE);
FlowL7DataPtrInit(&f);
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
if (de_ctx == NULL) {
goto end;
}
de_ctx->mpm_matcher = MPM_B2G;
de_ctx->flags |= DE_QUIET;
de_ctx->sig_list = SigInit(de_ctx, "alert tcp any any -> any any "
"(msg:\"test multiple relative uricontents\"; "
"uricontent:fix; uricontent:this; within:6; "
"uricontent:!\"and\"; distance:0; sid:1;)");
if (de_ctx->sig_list == NULL) {
goto end;
}
SigGroupBuild(de_ctx);
DetectEngineThreadCtxInit(&tv, (void *)de_ctx, (void *)&det_ctx);
int r = AppLayerParse(&f, ALPROTO_HTTP, STREAM_TOSERVER, http_buf, http_buf_len);
if (r != 0) {
printf("toserver chunk 1 returned %" PRId32 ", expected 0: ", r);
goto end;
}
http_state = f.aldata[AlpGetStateIdx(ALPROTO_HTTP)];
if (http_state == NULL) {
printf("no http state: ");
goto end;
}
/* do detect */
SigMatchSignatures(&tv, de_ctx, det_ctx, &p);
if (PacketAlertCheck(&p, 1)) {
printf("sig 1 alerted, but it should not: ");
goto end;
}
result = 1;
end:
if (det_ctx != NULL)
DetectEngineThreadCtxDeinit(&tv, det_ctx);
if (de_ctx != NULL)
SigGroupCleanup(de_ctx);
if (de_ctx != NULL)
DetectEngineCtxFree(de_ctx);
StreamTcpFreeConfig(TRUE);
FLOW_DESTROY(&f);
return result;
}
#endif /* UNITTESTS */
void UriRegisterTests(void)
......
UtRegisterTest("UriTestSig18", UriTestSig18, 1);
UtRegisterTest("UriTestSig19", UriTestSig19, 1);
UtRegisterTest("UriTestSig20", UriTestSig20, 1);
UtRegisterTest("UriTestSig21", UriTestSig21, 1);
#endif /* UNITTESTS */
return;
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