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suricata/src/detect-engine-frame.c

611 lines
23 KiB
C

/* Copyright (C) 2021-2023 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 Victor Julien <victor@inliniac.net>
*
*/
#include "suricata-common.h"
#include "suricata.h"
#include "app-layer-parser.h"
#include "app-layer-frames.h"
#include "detect-engine.h"
#include "detect-engine-prefilter.h"
#include "detect-engine-content-inspection.h"
#include "detect-engine-mpm.h"
#include "detect-engine-frame.h"
#include "stream-tcp.h"
#include "util-profiling.h"
#include "util-validate.h"
#include "util-print.h"
struct FrameStreamData {
// shared between prefilter and inspect
DetectEngineThreadCtx *det_ctx;
const DetectEngineTransforms *transforms;
const Frame *frame;
int list_id;
uint32_t idx; /**< multi buffer idx, incremented for each stream chunk */
// inspection only
const DetectEngineFrameInspectionEngine *inspect_engine;
const Signature *s;
int inspect_result; // DETECT_ENGINE_INSPECT_SIG_MATCH / DETECT_ENGINE_INSPECT_SIG_NO_MATCH
Packet *p;
// prefilter only
const MpmCtx *mpm_ctx;
uint64_t requested_stream_offset;
};
static bool SetupStreamCallbackData(struct FrameStreamData *dst, const TcpSession *ssn,
const TcpStream *stream, DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms, const Frames *_frames, const Frame *frame,
const int list_id, const bool eof);
static bool BufferSetup(struct FrameStreamData *fsd, InspectionBuffer *buffer, const uint8_t *input,
const uint32_t input_len, const uint64_t input_offset);
static void BufferSetupUdp(InspectionBuffer *buffer, const Frame *frame, const Packet *p,
const DetectEngineTransforms *transforms);
void DetectRunPrefilterFrame(DetectEngineThreadCtx *det_ctx, const SigGroupHead *sgh, Packet *p,
const Frames *frames, const Frame *frame, const AppProto alproto)
{
SCLogDebug("pcap_cnt %" PRIu64, p->pcap_cnt);
PrefilterEngine *engine = sgh->frame_engines;
do {
BUG_ON(engine->alproto == ALPROTO_UNKNOWN);
if (engine->alproto == alproto && engine->ctx.frame_type == frame->type) {
SCLogDebug("frame %p engine %p", frame, engine);
PREFILTER_PROFILING_START(det_ctx);
engine->cb.PrefilterFrame(det_ctx, engine->pectx, p, frames, frame);
PREFILTER_PROFILING_END(det_ctx, engine->gid);
}
if (engine->is_last)
break;
engine++;
} while (1);
}
/* generic mpm for frame engines */
// TODO same as Generic?
typedef struct PrefilterMpmFrameCtx {
int list_id;
const MpmCtx *mpm_ctx;
const DetectEngineTransforms *transforms;
} PrefilterMpmFrameCtx;
static int FrameStreamDataPrefilterFunc(
void *cb_data, const uint8_t *input, const uint32_t input_len, const uint64_t input_offset)
{
struct FrameStreamData *fsd = cb_data;
SCLogDebug("prefilter: fsd %p { det_ctx:%p, transforms:%p, frame:%p, list_id:%d, idx:%u, "
"data_offset:%" PRIu64 "}, input: %p, input_len:%u, input_offset:%" PRIu64,
fsd, fsd->det_ctx, fsd->transforms, fsd->frame, fsd->list_id, fsd->idx,
fsd->requested_stream_offset, input, input_len, input_offset);
// PrintRawDataFp(stdout, input, input_len);
InspectionBuffer *buffer =
InspectionBufferMultipleForListGet(fsd->det_ctx, fsd->list_id, fsd->idx++);
if (buffer == NULL) {
return 0;
}
SCLogDebug("buffer %p idx %u", buffer, fsd->idx);
const int more_chunks = BufferSetup(fsd, buffer, input, input_len, input_offset);
const uint32_t data_len = buffer->inspect_len;
const uint8_t *data = buffer->inspect;
DetectEngineThreadCtx *det_ctx = fsd->det_ctx;
const MpmCtx *mpm_ctx = fsd->mpm_ctx;
if (data != NULL && data_len >= mpm_ctx->minlen) {
// PrintRawDataFp(stdout, data, data_len);
(void)mpm_table[mpm_ctx->mpm_type].Search(
mpm_ctx, &det_ctx->mtcu, &det_ctx->pmq, data, data_len);
SCLogDebug("det_ctx->pmq.rule_id_array_cnt %u", det_ctx->pmq.rule_id_array_cnt);
PREFILTER_PROFILING_ADD_BYTES(det_ctx, data_len);
}
return more_chunks;
}
/** \brief Generic Mpm prefilter callback
*
* \param det_ctx detection engine thread ctx
* \param frames container for the frames
* \param frame frame to inspect
* \param pectx inspection context
*/
static void PrefilterMpmFrame(DetectEngineThreadCtx *det_ctx, const void *pectx, Packet *p,
const Frames *frames, const Frame *frame)
{
SCEnter();
const PrefilterMpmFrameCtx *ctx = (const PrefilterMpmFrameCtx *)pectx;
const MpmCtx *mpm_ctx = ctx->mpm_ctx;
SCLogDebug("packet:%" PRIu64 ", prefilter running on list %d -> frame field type %u",
p->pcap_cnt, ctx->list_id, frame->type);
if (p->proto == IPPROTO_UDP) {
// TODO can we use single here? Could it conflict with TCP?
InspectionBuffer *buffer = InspectionBufferMultipleForListGet(det_ctx, ctx->list_id, 0);
if (buffer == NULL)
return;
DEBUG_VALIDATE_BUG_ON(frame->offset >= p->payload_len);
if (frame->offset >= p->payload_len)
return;
BufferSetupUdp(buffer, frame, p, ctx->transforms);
const uint32_t data_len = buffer->inspect_len;
const uint8_t *data = buffer->inspect;
// PrintRawDataFp(stdout, data, data_len);
if (data != NULL && data_len >= mpm_ctx->minlen) {
(void)mpm_table[mpm_ctx->mpm_type].Search(
mpm_ctx, &det_ctx->mtcu, &det_ctx->pmq, data, data_len);
SCLogDebug("det_ctx->pmq.rule_id_array_cnt %u", det_ctx->pmq.rule_id_array_cnt);
PREFILTER_PROFILING_ADD_BYTES(det_ctx, data_len);
}
} else if (p->proto == IPPROTO_TCP) {
BUG_ON(p->flow->protoctx == NULL);
TcpSession *ssn = p->flow->protoctx;
TcpStream *stream;
if (PKT_IS_TOSERVER(p)) {
stream = &ssn->client;
} else {
stream = &ssn->server;
}
const bool eof = ssn->state == TCP_CLOSED || PKT_IS_PSEUDOPKT(p);
struct FrameStreamData fsd;
memset(&fsd, 0, sizeof(fsd));
fsd.mpm_ctx = mpm_ctx;
if (SetupStreamCallbackData(&fsd, ssn, stream, det_ctx, ctx->transforms, frames, frame,
ctx->list_id, eof) == true) {
StreamReassembleForFrame(ssn, stream, FrameStreamDataPrefilterFunc, &fsd,
fsd.requested_stream_offset, eof);
}
} else {
DEBUG_VALIDATE_BUG_ON(1);
}
SCLogDebug("packet:%" PRIu64
", prefilter done running on list %d -> frame field type %u; have %u matches",
p->pcap_cnt, ctx->list_id, frame->type, det_ctx->pmq.rule_id_array_cnt);
}
static void PrefilterMpmFrameFree(void *ptr)
{
SCFree(ptr);
}
int PrefilterGenericMpmFrameRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx,
const DetectBufferMpmRegistry *mpm_reg, int list_id)
{
SCEnter();
PrefilterMpmFrameCtx *pectx = SCCalloc(1, sizeof(*pectx));
if (pectx == NULL)
return -1;
pectx->list_id = list_id;
BUG_ON(mpm_reg->frame_v1.alproto == ALPROTO_UNKNOWN);
pectx->mpm_ctx = mpm_ctx;
pectx->transforms = &mpm_reg->transforms;
int r = PrefilterAppendFrameEngine(de_ctx, sgh, PrefilterMpmFrame, mpm_reg->frame_v1.alproto,
mpm_reg->frame_v1.type, pectx, PrefilterMpmFrameFree, mpm_reg->pname);
if (r != 0) {
SCFree(pectx);
}
return r;
}
int DetectRunFrameInspectRule(ThreadVars *tv, DetectEngineThreadCtx *det_ctx, const Signature *s,
Flow *f, Packet *p, const Frames *frames, const Frame *frame)
{
BUG_ON(s->frame_inspect == NULL);
SCLogDebug("inspecting rule %u against frame %p/%" PRIi64 "/%s", s->id, frame, frame->id,
AppLayerParserGetFrameNameById(f->proto, f->alproto, frame->type));
for (DetectEngineFrameInspectionEngine *e = s->frame_inspect; e != NULL; e = e->next) {
if (frame->type == e->type) {
// TODO check alproto, direction?
// TODO there should be only one inspect engine for this frame, ever?
if (e->v1.Callback(det_ctx, e, s, p, frames, frame) == true) {
SCLogDebug("sid %u: e %p Callback returned true", s->id, e);
return true;
}
SCLogDebug("sid %u: e %p Callback returned false", s->id, e);
} else {
SCLogDebug(
"sid %u: e %p not for frame type %u (want %u)", s->id, e, frame->type, e->type);
}
}
return false;
}
static void BufferSetupUdp(InspectionBuffer *buffer, const Frame *frame, const Packet *p,
const DetectEngineTransforms *transforms)
{
uint8_t ci_flags = DETECT_CI_FLAGS_START;
uint32_t frame_len;
if (frame->len == -1) {
frame_len = p->payload_len - frame->offset;
} else {
frame_len = (uint32_t)frame->len;
}
if (frame->offset + frame_len > p->payload_len) {
frame_len = p->payload_len - frame->offset;
} else {
ci_flags |= DETECT_CI_FLAGS_END;
}
const uint8_t *data = p->payload + frame->offset;
const uint32_t data_len = frame_len;
SCLogDebug("packet %" PRIu64 " -> frame %p/%" PRIi64 "/%s offset %" PRIu64
" type %u len %" PRIi64,
p->pcap_cnt, frame, frame->id,
AppLayerParserGetFrameNameById(p->flow->proto, p->flow->alproto, frame->type),
frame->offset, frame->type, frame->len);
InspectionBufferSetupMulti(buffer, transforms, data, data_len);
buffer->inspect_offset = 0;
buffer->flags = ci_flags;
}
/** \internal
* \brief setup buffer based on frame in UDP payload
*/
static int DetectFrameInspectUdp(DetectEngineThreadCtx *det_ctx,
const DetectEngineFrameInspectionEngine *engine, const Signature *s,
const DetectEngineTransforms *transforms, Packet *p, const Frames *_frames,
const Frame *frame, const int list_id)
{
SCLogDebug("packet:%" PRIu64 ", inspect: s:%p s->id:%u, transforms:%p", p->pcap_cnt, s, s->id,
transforms);
// TODO can we use single here? Could it conflict with TCP?
InspectionBuffer *buffer = InspectionBufferMultipleForListGet(det_ctx, list_id, 0);
if (buffer == NULL)
return DETECT_ENGINE_INSPECT_SIG_NO_MATCH;
DEBUG_VALIDATE_BUG_ON(frame->offset >= p->payload_len);
if (frame->offset >= p->payload_len)
return DETECT_ENGINE_INSPECT_SIG_NO_MATCH;
if (!buffer->initialized)
BufferSetupUdp(buffer, frame, p, transforms);
DEBUG_VALIDATE_BUG_ON(!buffer->initialized);
if (buffer->inspect == NULL)
return DETECT_ENGINE_INSPECT_SIG_NO_MATCH;
const uint32_t data_len = buffer->inspect_len;
const uint8_t *data = buffer->inspect;
// PrintRawDataFp(stdout, data, data_len);
int r = DetectEngineContentInspection(det_ctx->de_ctx, det_ctx, s, engine->smd, p, p->flow,
(uint8_t *)data, data_len, 0, buffer->flags,
DETECT_ENGINE_CONTENT_INSPECTION_MODE_FRAME);
if (r == 1) {
SCLogDebug("match!");
return DETECT_ENGINE_INSPECT_SIG_MATCH;
} else {
return DETECT_ENGINE_INSPECT_SIG_NO_MATCH;
}
}
/**
* \retval bool true if callback should run again */
static bool BufferSetup(struct FrameStreamData *fsd, InspectionBuffer *buffer, const uint8_t *input,
const uint32_t input_len, const uint64_t input_offset)
{
const Frame *frame = fsd->frame;
/* so: relative to start of stream */
const uint64_t so_input_re = input_offset + input_len;
const uint64_t so_frame_re =
frame->offset + (uint64_t)frame->len; // TODO if eof, set to available data?
SCLogDebug("frame offset:%" PRIu64, frame->offset);
const uint8_t *data = input;
uint8_t ci_flags = 0;
uint32_t data_len;
/* fo: frame offset; offset relative to start of the frame */
uint64_t fo_inspect_offset = 0;
if (frame->offset == 0 && input_offset == 0) {
ci_flags |= DETECT_CI_FLAGS_START;
SCLogDebug("have frame data start");
if (frame->len >= 0) {
data_len = MIN(input_len, frame->len);
if (data_len == frame->len) {
ci_flags |= DETECT_CI_FLAGS_END;
SCLogDebug("have frame data end");
}
} else {
data_len = input_len;
}
} else {
const uint64_t so_frame_inspect_offset = frame->inspect_progress + frame->offset;
const uint64_t so_inspect_offset = MAX(input_offset, so_frame_inspect_offset);
fo_inspect_offset = so_inspect_offset - frame->offset;
if (frame->offset >= input_offset) {
ci_flags |= DETECT_CI_FLAGS_START;
SCLogDebug("have frame data start");
}
if (frame->len >= 0) {
if (fo_inspect_offset >= (uint64_t)frame->len) {
SCLogDebug("data entirely past frame (%" PRIu64 " > %" PRIi64 ")",
fo_inspect_offset, frame->len);
InspectionBufferSetupMultiEmpty(buffer);
return false;
}
/* in: relative to start of input data */
BUG_ON(so_inspect_offset < input_offset);
const uint32_t in_data_offset = so_inspect_offset - input_offset;
data += in_data_offset;
uint32_t in_data_excess = 0;
if (so_input_re >= so_frame_re) {
ci_flags |= DETECT_CI_FLAGS_END;
SCLogDebug("have frame data end");
in_data_excess = so_input_re - so_frame_re;
}
data_len = input_len - in_data_offset - in_data_excess;
} else {
/* in: relative to start of input data */
BUG_ON(so_inspect_offset < input_offset);
const uint32_t in_data_offset = so_inspect_offset - input_offset;
data += in_data_offset;
data_len = input_len - in_data_offset;
}
}
// PrintRawDataFp(stdout, data, data_len);
SCLogDebug("fsd->transforms %p", fsd->transforms);
InspectionBufferSetupMulti(buffer, fsd->transforms, data, data_len);
SCLogDebug("inspect_offset %" PRIu64, fo_inspect_offset);
buffer->inspect_offset = fo_inspect_offset;
buffer->flags = ci_flags;
if (frame->len >= 0 && so_input_re >= so_frame_re) {
SCLogDebug("have the full frame, we can set progress accordingly (%" PRIu64 " > %" PRIu64
")",
so_input_re, so_frame_re);
fsd->det_ctx->frame_inspect_progress =
MAX(fo_inspect_offset + data_len, fsd->det_ctx->frame_inspect_progress);
} else {
fsd->det_ctx->frame_inspect_progress =
MAX(fo_inspect_offset + data_len, fsd->det_ctx->frame_inspect_progress);
/* in IPS mode keep a sliding window */
const bool ips = StreamTcpInlineMode();
if (ips) {
if (fsd->det_ctx->frame_inspect_progress < 2500)
fsd->det_ctx->frame_inspect_progress = 0;
else
fsd->det_ctx->frame_inspect_progress -= 2500;
}
SCLogDebug("ips %s inspect_progress %" PRIu64, BOOL2STR(ips),
fsd->det_ctx->frame_inspect_progress);
}
/* keep going as long as there is possibly still data for this frame */
const bool ret = (frame->len >= 0 && so_input_re >= so_frame_re);
SCLogDebug("buffer set up, more to do: %s", BOOL2STR(ret));
return ret;
}
static int FrameStreamDataInspectFunc(
void *cb_data, const uint8_t *input, const uint32_t input_len, const uint64_t input_offset)
{
struct FrameStreamData *fsd = cb_data;
SCLogDebug("inspect: fsd %p { det_ctx:%p, transforms:%p, s:%p, s->id:%u, frame:%p, list_id:%d, "
"idx:%u, "
"requested_stream_offset:%" PRIu64
"}, input: %p, input_len:%u, input_offset:%" PRIu64,
fsd, fsd->det_ctx, fsd->transforms, fsd->s, fsd->s->id, fsd->frame, fsd->list_id,
fsd->idx, fsd->requested_stream_offset, input, input_len, input_offset);
// PrintRawDataFp(stdout, input, input_len);
InspectionBuffer *buffer =
InspectionBufferMultipleForListGet(fsd->det_ctx, fsd->list_id, fsd->idx++);
if (buffer == NULL) {
return 0;
}
SCLogDebug("buffer %p idx %u", buffer, fsd->idx);
/* if we've not done so already, set up the buffer */
int more_chunks = 1;
if (!buffer->initialized) {
more_chunks = BufferSetup(fsd, buffer, input, input_len, input_offset);
}
DEBUG_VALIDATE_BUG_ON(!buffer->initialized);
if (buffer->inspect == NULL) {
return more_chunks;
}
const uint32_t data_len = buffer->inspect_len;
const uint8_t *data = buffer->inspect;
const uint64_t data_offset = buffer->inspect_offset;
DetectEngineThreadCtx *det_ctx = fsd->det_ctx;
det_ctx->discontinue_matching = 0;
det_ctx->buffer_offset = 0;
det_ctx->inspection_recursion_counter = 0;
const DetectEngineFrameInspectionEngine *engine = fsd->inspect_engine;
const Signature *s = fsd->s;
Packet *p = fsd->p;
#ifdef DEBUG
const uint8_t ci_flags = buffer->flags;
SCLogDebug("frame %p offset %" PRIu64 " type %u len %" PRIi64
" ci_flags %02x (start:%s, end:%s)",
fsd->frame, fsd->frame->offset, fsd->frame->type, fsd->frame->len, ci_flags,
(ci_flags & DETECT_CI_FLAGS_START) ? "true" : "false",
(ci_flags & DETECT_CI_FLAGS_END) ? "true" : "false");
SCLogDebug("buffer %p offset %" PRIu64 " len %u ci_flags %02x (start:%s, end:%s)", buffer,
buffer->inspect_offset, buffer->inspect_len, ci_flags,
(ci_flags & DETECT_CI_FLAGS_START) ? "true" : "false",
(ci_flags & DETECT_CI_FLAGS_END) ? "true" : "false");
// PrintRawDataFp(stdout, data, data_len);
// PrintRawDataFp(stdout, data, MIN(64, data_len));
#endif
BUG_ON(fsd->frame->len > 0 && (int64_t)data_len > fsd->frame->len);
int r = DetectEngineContentInspection(det_ctx->de_ctx, det_ctx, s, engine->smd, p, p->flow,
(uint8_t *)data, data_len, data_offset, buffer->flags,
DETECT_ENGINE_CONTENT_INSPECTION_MODE_FRAME);
if (r == 1) {
SCLogDebug("DETECT_ENGINE_INSPECT_SIG_MATCH");
fsd->inspect_result = DETECT_ENGINE_INSPECT_SIG_MATCH;
} else {
SCLogDebug("DETECT_ENGINE_INSPECT_SIG_NO_MATCH");
}
return more_chunks;
}
static bool SetupStreamCallbackData(struct FrameStreamData *dst, const TcpSession *ssn,
const TcpStream *stream, DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms, const Frames *_frames, const Frame *frame,
const int list_id, const bool eof)
{
SCLogDebug("frame %" PRIi64 ", len %" PRIi64 ", offset %" PRIu64 ", inspect_progress %" PRIu64,
frame->id, frame->len, frame->offset, frame->inspect_progress);
const uint64_t frame_offset = frame->offset;
const uint64_t usable = StreamDataRightEdge(stream, eof);
if (usable <= frame_offset)
return false;
uint64_t want = frame->inspect_progress;
if (frame->len == -1) {
if (eof) {
want = usable;
} else {
want += 2500;
}
} else {
/* don't have the full frame yet */
if (frame->offset + frame->len > usable) {
want += 2500;
} else {
want = frame->offset + frame->len;
}
}
const bool ips = StreamTcpInlineMode();
const uint64_t have = usable;
if (!ips && have < want) {
SCLogDebug("wanted %" PRIu64 " bytes, got %" PRIu64, want, have);
return false;
}
const uint64_t available_data = usable - STREAM_BASE_OFFSET(stream);
SCLogDebug("check inspection for having 2500 bytes: %" PRIu64, available_data);
if (!ips && !eof && available_data < 2500 &&
(frame->len < 0 || frame->len > (int64_t)available_data)) {
SCLogDebug("skip inspection until we have 2500 bytes (have %" PRIu64 ")", available_data);
return false;
}
const uint64_t offset =
MAX(STREAM_BASE_OFFSET(stream), frame->offset + frame->inspect_progress);
dst->det_ctx = det_ctx;
dst->transforms = transforms;
dst->frame = frame;
dst->list_id = list_id;
dst->requested_stream_offset = offset;
return true;
}
/**
* \brief Do the content inspection & validation for a signature
*
* \param de_ctx Detection engine context
* \param det_ctx Detection engine thread context
* \param s Signature to inspect
* \param p Packet
* \param frame stream frame to inspect
*
* \retval 0 no match.
* \retval 1 match.
*/
int DetectEngineInspectFrameBufferGeneric(DetectEngineThreadCtx *det_ctx,
const DetectEngineFrameInspectionEngine *engine, const Signature *s, Packet *p,
const Frames *frames, const Frame *frame)
{
/* if prefilter didn't already run, we need to consider transformations */
const DetectEngineTransforms *transforms = NULL;
if (!engine->mpm) {
transforms = engine->v1.transforms;
}
const int list_id = engine->sm_list;
SCLogDebug("running inspect on %d", list_id);
if (p->proto == IPPROTO_UDP) {
return DetectFrameInspectUdp(det_ctx, engine, s, transforms, p, frames, frame, list_id);
}
DEBUG_VALIDATE_BUG_ON(p->proto != IPPROTO_TCP);
SCLogDebug("packet:%" PRIu64 ", frame->id:%" PRIu64
", list:%d, transforms:%p, s:%p, s->id:%u, engine:%p",
p->pcap_cnt, frame->id, engine->sm_list, engine->v1.transforms, s, s->id, engine);
BUG_ON(p->flow->protoctx == NULL);
TcpSession *ssn = p->flow->protoctx;
TcpStream *stream;
if (PKT_IS_TOSERVER(p)) {
stream = &ssn->client;
} else {
stream = &ssn->server;
}
const bool eof = ssn->state == TCP_CLOSED || PKT_IS_PSEUDOPKT(p);
struct FrameStreamData fsd;
memset(&fsd, 0, sizeof(fsd));
fsd.inspect_engine = engine;
fsd.s = s;
fsd.inspect_result = DETECT_ENGINE_INSPECT_SIG_NO_MATCH;
fsd.p = p;
if (SetupStreamCallbackData(
&fsd, ssn, stream, det_ctx, transforms, frames, frame, list_id, eof) == false) {
return DETECT_ENGINE_INSPECT_SIG_NO_MATCH;
}
StreamReassembleForFrame(
ssn, stream, FrameStreamDataInspectFunc, &fsd, fsd.requested_stream_offset, eof);
return fsd.inspect_result;
}