detect/dce_stub_data: add dcerpc.stub_data

Also use v2 API for inspect and mpm registration.
pull/3826/head
Victor Julien 7 years ago
parent d270a7603a
commit 3b31bad855

@ -64,165 +64,56 @@ static int DetectDceStubDataSetup(DetectEngineCtx *, Signature *, const char *);
static void DetectDceStubDataRegisterTests(void);
static int g_dce_stub_data_buffer_id = 0;
/** \brief DCERPC Stub Data Mpm prefilter callback
*
* \param det_ctx detection engine thread ctx
* \param p packet to inspect
* \param f flow to inspect
* \param txv tx to inspect
* \param pectx inspection context
*/
static void PrefilterTxDceStubDataRequest(DetectEngineThreadCtx *det_ctx,
const void *pectx,
Packet *p, Flow *f, void *txv,
const uint64_t idx, const uint8_t flags)
static InspectionBuffer *GetSMBData(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms,
Flow *_f, const uint8_t flow_flags,
void *txv, const int list_id)
{
SCEnter();
const MpmCtx *mpm_ctx = (MpmCtx *)pectx;
uint8_t *buffer;
uint32_t buffer_len;
if (f->alproto == ALPROTO_SMB) {
if (rs_smb_tx_get_stub_data(txv, STREAM_TOSERVER, &buffer, &buffer_len) != 1) {
SCLogDebug("have no data!");
return;
}
InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
if (buffer->inspect == NULL) {
uint32_t data_len = 0;
uint8_t *data = NULL;
uint8_t dir = flow_flags & (STREAM_TOSERVER|STREAM_TOCLIENT);
if (rs_smb_tx_get_stub_data(txv, dir, &data, &data_len) != 1)
return NULL;
SCLogDebug("have data!");
} else {
DCERPCState *dcerpc_state = f->alstate;
if (dcerpc_state == NULL)
return;
buffer_len = dcerpc_state->dcerpc.dcerpcrequest.stub_data_buffer_len;
buffer = dcerpc_state->dcerpc.dcerpcrequest.stub_data_buffer;
}
if (buffer_len >= mpm_ctx->minlen) {
(void)mpm_table[mpm_ctx->mpm_type].Search(mpm_ctx,
&det_ctx->mtcu, &det_ctx->pmq, buffer, buffer_len);
InspectionBufferSetup(buffer, data, data_len);
InspectionBufferApplyTransforms(buffer, transforms);
}
return buffer;
}
static int PrefilterTxDceStubDataRequestRegister(DetectEngineCtx *de_ctx,
SigGroupHead *sgh, MpmCtx *mpm_ctx)
static InspectionBuffer *GetDCEData(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms,
Flow *_f, const uint8_t flow_flags,
void *txv, const int list_id)
{
SCEnter();
int r = PrefilterAppendTxEngine(de_ctx, sgh, PrefilterTxDceStubDataRequest,
ALPROTO_DCERPC, 0,
mpm_ctx, NULL, KEYWORD_NAME " (request)");
if (r == 0) {
r = PrefilterAppendTxEngine(de_ctx, sgh, PrefilterTxDceStubDataRequest,
ALPROTO_SMB, 0,
mpm_ctx, NULL, KEYWORD_NAME " (request)");
}
return r;
}
InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
if (buffer->inspect == NULL) {
uint32_t data_len = 0;
uint8_t *data = NULL;
/** \brief DCERPC Stub Data Mpm prefilter callback
*
* \param det_ctx detection engine thread ctx
* \param p packet to inspect
* \param f flow to inspect
* \param txv tx to inspect
* \param pectx inspection context
*/
static void PrefilterTxDceStubDataResponse(DetectEngineThreadCtx *det_ctx,
const void *pectx,
Packet *p, Flow *f, void *txv,
const uint64_t idx, const uint8_t flags)
{
SCEnter();
const MpmCtx *mpm_ctx = (MpmCtx *)pectx;
uint8_t *buffer;
uint32_t buffer_len;
if (f->alproto == ALPROTO_SMB) {
if (rs_smb_tx_get_stub_data(txv, STREAM_TOCLIENT, &buffer, &buffer_len) != 1) {
SCLogDebug("have no data!");
return;
}
SCLogDebug("have data!");
} else {
DCERPCState *dcerpc_state = f->alstate;
DCERPCState *dcerpc_state = txv;
if (dcerpc_state == NULL)
return;
buffer_len = dcerpc_state->dcerpc.dcerpcresponse.stub_data_buffer_len;
buffer = dcerpc_state->dcerpc.dcerpcresponse.stub_data_buffer;
}
if (buffer_len >= mpm_ctx->minlen) {
(void)mpm_table[mpm_ctx->mpm_type].Search(mpm_ctx,
&det_ctx->mtcu, &det_ctx->pmq, buffer, buffer_len);
}
}
static int PrefilterTxDceStubDataResponseRegister(DetectEngineCtx *de_ctx,
SigGroupHead *sgh, MpmCtx *mpm_ctx)
{
SCEnter();
int r = PrefilterAppendTxEngine(de_ctx, sgh, PrefilterTxDceStubDataResponse,
ALPROTO_DCERPC, 0,
mpm_ctx, NULL, KEYWORD_NAME " (response)");
if (r == 0) {
r = PrefilterAppendTxEngine(de_ctx, sgh, PrefilterTxDceStubDataResponse,
ALPROTO_SMB, 0,
mpm_ctx, NULL, KEYWORD_NAME " (response)");
}
return r;
}
static int InspectEngineDceStubData(ThreadVars *tv,
DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx,
const Signature *s, const SigMatchData *smd,
Flow *f, uint8_t flags, void *alstate, void *tx, uint64_t tx_id)
{
uint32_t buffer_len = 0;
uint8_t *buffer = NULL;
uint8_t ci_flags = DETECT_CI_FLAGS_SINGLE;
if (f->alproto == ALPROTO_SMB) {
uint8_t dir = flags & (STREAM_TOSERVER|STREAM_TOCLIENT);
if (rs_smb_tx_get_stub_data(tx, dir, &buffer, &buffer_len) != 1)
goto end;
SCLogDebug("have data!");
} else {
DCERPCState *dcerpc_state = alstate;
if (dcerpc_state == NULL)
goto end;
if (flags & STREAM_TOSERVER) {
buffer_len = dcerpc_state->dcerpc.dcerpcrequest.stub_data_buffer_len;
buffer = dcerpc_state->dcerpc.dcerpcrequest.stub_data_buffer;
} else if (flags & STREAM_TOCLIENT) {
buffer_len = dcerpc_state->dcerpc.dcerpcresponse.stub_data_buffer_len;
buffer = dcerpc_state->dcerpc.dcerpcresponse.stub_data_buffer;
return NULL;
if (flow_flags & STREAM_TOSERVER) {
data_len = dcerpc_state->dcerpc.dcerpcrequest.stub_data_buffer_len;
data = dcerpc_state->dcerpc.dcerpcrequest.stub_data_buffer;
} else if (flow_flags & STREAM_TOCLIENT) {
data_len = dcerpc_state->dcerpc.dcerpcresponse.stub_data_buffer_len;
data = dcerpc_state->dcerpc.dcerpcresponse.stub_data_buffer;
}
if (dcerpc_state->dcerpc.dcerpchdr.packed_drep[0] & 0x10) {
ci_flags |= DETECT_CI_FLAGS_DCE_LE;
buffer->flags = DETECT_CI_FLAGS_DCE_LE;
} else {
ci_flags |= DETECT_CI_FLAGS_DCE_BE;
buffer->flags |= DETECT_CI_FLAGS_DCE_BE;
}
InspectionBufferSetup(buffer, data, data_len);
InspectionBufferApplyTransforms(buffer, transforms);
}
if (buffer == NULL ||buffer_len == 0)
goto end;
det_ctx->buffer_offset = 0;
det_ctx->discontinue_matching = 0;
det_ctx->inspection_recursion_counter = 0;
int r = DetectEngineContentInspection(de_ctx, det_ctx, s, smd,
NULL, f,
buffer, buffer_len,
0, ci_flags,
DETECT_ENGINE_CONTENT_INSPECTION_MODE_STATE);
if (r == 1)
return DETECT_ENGINE_INSPECT_SIG_MATCH;
end:
return DETECT_ENGINE_INSPECT_SIG_NO_MATCH;
return buffer;
}
/**
@ -230,30 +121,41 @@ end:
*/
void DetectDceStubDataRegister(void)
{
sigmatch_table[DETECT_DCE_STUB_DATA].name = "dce_stub_data";
sigmatch_table[DETECT_DCE_STUB_DATA].name = "dcerpc.stub_data";
sigmatch_table[DETECT_DCE_STUB_DATA].alias = "dce_stub_data";
sigmatch_table[DETECT_DCE_STUB_DATA].Setup = DetectDceStubDataSetup;
sigmatch_table[DETECT_DCE_STUB_DATA].RegisterTests = DetectDceStubDataRegisterTests;
sigmatch_table[DETECT_DCE_STUB_DATA].flags |= SIGMATCH_NOOPT|SIGMATCH_INFO_STICKY_BUFFER;
sigmatch_table[DETECT_DCE_STUB_DATA].flags |= SIGMATCH_NOOPT;
DetectAppLayerMpmRegister(BUFFER_NAME, SIG_FLAG_TOSERVER, 2,
PrefilterTxDceStubDataRequestRegister);
DetectAppLayerMpmRegister(BUFFER_NAME, SIG_FLAG_TOCLIENT, 2,
PrefilterTxDceStubDataResponseRegister);
DetectAppLayerInspectEngineRegister2(BUFFER_NAME,
ALPROTO_SMB, SIG_FLAG_TOSERVER, 0,
DetectEngineInspectBufferGeneric,
GetSMBData);
DetectAppLayerMpmRegister2(BUFFER_NAME, SIG_FLAG_TOSERVER, 2,
PrefilterGenericMpmRegister, GetSMBData,
ALPROTO_SMB, 0);
DetectAppLayerInspectEngineRegister2(BUFFER_NAME,
ALPROTO_SMB, SIG_FLAG_TOCLIENT, 0,
DetectEngineInspectBufferGeneric,
GetSMBData);
DetectAppLayerMpmRegister2(BUFFER_NAME, SIG_FLAG_TOCLIENT, 2,
PrefilterGenericMpmRegister, GetSMBData,
ALPROTO_SMB, 0);
DetectAppLayerInspectEngineRegister(BUFFER_NAME,
DetectAppLayerInspectEngineRegister2(BUFFER_NAME,
ALPROTO_DCERPC, SIG_FLAG_TOSERVER, 0,
InspectEngineDceStubData);
DetectAppLayerInspectEngineRegister(BUFFER_NAME,
DetectEngineInspectBufferGeneric,
GetDCEData);
DetectAppLayerMpmRegister2(BUFFER_NAME, SIG_FLAG_TOSERVER, 2,
PrefilterGenericMpmRegister, GetDCEData,
ALPROTO_DCERPC, 0);
DetectAppLayerInspectEngineRegister2(BUFFER_NAME,
ALPROTO_DCERPC, SIG_FLAG_TOCLIENT, 0,
InspectEngineDceStubData);
DetectAppLayerInspectEngineRegister(BUFFER_NAME,
ALPROTO_SMB, SIG_FLAG_TOSERVER, 0,
InspectEngineDceStubData);
DetectAppLayerInspectEngineRegister(BUFFER_NAME,
ALPROTO_SMB, SIG_FLAG_TOCLIENT, 0,
InspectEngineDceStubData);
DetectEngineInspectBufferGeneric,
GetDCEData);
DetectAppLayerMpmRegister2(BUFFER_NAME, SIG_FLAG_TOCLIENT, 2,
PrefilterGenericMpmRegister, GetDCEData,
ALPROTO_DCERPC, 0);
g_dce_stub_data_buffer_id = DetectBufferTypeGetByName(BUFFER_NAME);
}

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