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suricata/src/detect-engine-inspect-buffer.c

258 lines
8.6 KiB
C

/* Copyright (C) 2025 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 "detect-engine-inspect-buffer.h"
#include "detect.h"
#include "util-validate.h"
void InspectionBufferClean(DetectEngineThreadCtx *det_ctx)
{
/* single buffers */
for (uint32_t i = 0; i < det_ctx->inspect.to_clear_idx; i++) {
const uint32_t idx = det_ctx->inspect.to_clear_queue[i];
InspectionBuffer *buffer = &det_ctx->inspect.buffers[idx];
buffer->inspect = NULL;
buffer->initialized = false;
}
det_ctx->inspect.to_clear_idx = 0;
/* multi buffers */
for (uint32_t i = 0; i < det_ctx->multi_inspect.to_clear_idx; i++) {
const uint32_t idx = det_ctx->multi_inspect.to_clear_queue[i];
InspectionBufferMultipleForList *mbuffer = &det_ctx->multi_inspect.buffers[idx];
for (uint32_t x = 0; x <= mbuffer->max; x++) {
InspectionBuffer *buffer = &mbuffer->inspection_buffers[x];
buffer->inspect = NULL;
buffer->initialized = false;
}
mbuffer->init = 0;
mbuffer->max = 0;
}
det_ctx->multi_inspect.to_clear_idx = 0;
}
InspectionBuffer *InspectionBufferGet(DetectEngineThreadCtx *det_ctx, const int list_id)
{
return &det_ctx->inspect.buffers[list_id];
}
static InspectionBufferMultipleForList *InspectionBufferGetMulti(
DetectEngineThreadCtx *det_ctx, const int list_id)
{
InspectionBufferMultipleForList *buffer = &det_ctx->multi_inspect.buffers[list_id];
if (!buffer->init) {
det_ctx->multi_inspect.to_clear_queue[det_ctx->multi_inspect.to_clear_idx++] = list_id;
buffer->init = 1;
}
return buffer;
}
/** \brief for a InspectionBufferMultipleForList get a InspectionBuffer
* \param fb the multiple buffer array
* \param local_id the index to get a buffer
* \param buffer the inspect buffer or NULL in case of error */
InspectionBuffer *InspectionBufferMultipleForListGet(
DetectEngineThreadCtx *det_ctx, const int list_id, const uint32_t local_id)
{
if (unlikely(local_id >= 1024)) {
DetectEngineSetEvent(det_ctx, DETECT_EVENT_TOO_MANY_BUFFERS);
return NULL;
}
InspectionBufferMultipleForList *fb = InspectionBufferGetMulti(det_ctx, list_id);
if (local_id >= fb->size) {
uint32_t old_size = fb->size;
uint32_t new_size = local_id + 1;
uint32_t grow_by = new_size - old_size;
SCLogDebug("size is %u, need %u, so growing by %u", old_size, new_size, grow_by);
SCLogDebug("fb->inspection_buffers %p", fb->inspection_buffers);
void *ptr = SCRealloc(fb->inspection_buffers, (local_id + 1) * sizeof(InspectionBuffer));
if (ptr == NULL)
return NULL;
InspectionBuffer *to_zero = (InspectionBuffer *)ptr + old_size;
SCLogDebug("ptr %p to_zero %p", ptr, to_zero);
memset((uint8_t *)to_zero, 0, (grow_by * sizeof(InspectionBuffer)));
fb->inspection_buffers = ptr;
fb->size = new_size;
}
fb->max = MAX(fb->max, local_id);
InspectionBuffer *buffer = &fb->inspection_buffers[local_id];
SCLogDebug("using buffer %p", buffer);
#ifdef DEBUG_VALIDATION
buffer->multi = true;
#endif
return buffer;
}
static inline void InspectionBufferApplyTransformsInternal(DetectEngineThreadCtx *det_ctx,
InspectionBuffer *buffer, const DetectEngineTransforms *transforms)
{
if (transforms) {
for (int i = 0; i < DETECT_TRANSFORMS_MAX; i++) {
const int id = transforms->transforms[i].transform;
if (id == 0)
break;
BUG_ON(sigmatch_table[id].Transform == NULL);
sigmatch_table[id].Transform(det_ctx, buffer, transforms->transforms[i].options);
SCLogDebug("applied transform %s", sigmatch_table[id].name);
}
}
}
void InspectionBufferApplyTransforms(DetectEngineThreadCtx *det_ctx, InspectionBuffer *buffer,
const DetectEngineTransforms *transforms)
{
InspectionBufferApplyTransformsInternal(det_ctx, buffer, transforms);
}
void InspectionBufferInit(InspectionBuffer *buffer, uint32_t initial_size)
{
memset(buffer, 0, sizeof(*buffer));
buffer->buf = SCCalloc(initial_size, sizeof(uint8_t));
if (buffer->buf != NULL) {
buffer->size = initial_size;
}
}
/** \brief setup the buffer empty */
void InspectionBufferSetupMultiEmpty(InspectionBuffer *buffer)
{
#ifdef DEBUG_VALIDATION
DEBUG_VALIDATE_BUG_ON(buffer->initialized);
DEBUG_VALIDATE_BUG_ON(!buffer->multi);
#endif
buffer->inspect = NULL;
buffer->inspect_len = 0;
buffer->len = 0;
buffer->initialized = true;
}
/** \brief setup the buffer with our initial data */
void InspectionBufferSetupMulti(DetectEngineThreadCtx *det_ctx, InspectionBuffer *buffer,
const DetectEngineTransforms *transforms, const uint8_t *data, const uint32_t data_len)
{
#ifdef DEBUG_VALIDATION
DEBUG_VALIDATE_BUG_ON(!buffer->multi);
#endif
buffer->inspect = buffer->orig = data;
buffer->inspect_len = buffer->orig_len = data_len;
buffer->len = 0;
buffer->initialized = true;
InspectionBufferApplyTransformsInternal(det_ctx, buffer, transforms);
}
static inline void InspectionBufferSetupInternal(DetectEngineThreadCtx *det_ctx, const int list_id,
InspectionBuffer *buffer, const uint8_t *data, const uint32_t data_len)
{
#ifdef DEBUG_VALIDATION
DEBUG_VALIDATE_BUG_ON(buffer->multi);
DEBUG_VALIDATE_BUG_ON(buffer != InspectionBufferGet(det_ctx, list_id));
#endif
if (buffer->inspect == NULL) {
#ifdef UNITTESTS
if (det_ctx && list_id != -1)
#endif
det_ctx->inspect.to_clear_queue[det_ctx->inspect.to_clear_idx++] = list_id;
}
buffer->inspect = buffer->orig = data;
buffer->inspect_len = buffer->orig_len = data_len;
buffer->len = 0;
buffer->initialized = true;
}
/** \brief setup the buffer with our initial data */
void InspectionBufferSetup(DetectEngineThreadCtx *det_ctx, const int list_id,
InspectionBuffer *buffer, const uint8_t *data, const uint32_t data_len)
{
InspectionBufferSetupInternal(det_ctx, list_id, buffer, data, data_len);
}
/** \brief setup the buffer with our initial data */
void InspectionBufferSetupAndApplyTransforms(DetectEngineThreadCtx *det_ctx, const int list_id,
InspectionBuffer *buffer, const uint8_t *data, const uint32_t data_len,
const DetectEngineTransforms *transforms)
{
InspectionBufferSetupInternal(det_ctx, list_id, buffer, data, data_len);
InspectionBufferApplyTransformsInternal(det_ctx, buffer, transforms);
}
void InspectionBufferFree(InspectionBuffer *buffer)
{
if (buffer->buf != NULL) {
SCFree(buffer->buf);
}
memset(buffer, 0, sizeof(*buffer));
}
/**
* \brief make sure that the buffer has at least 'min_size' bytes
* Expand the buffer if necessary
*/
uint8_t *SCInspectionBufferCheckAndExpand(InspectionBuffer *buffer, uint32_t min_size)
{
if (likely(buffer->size >= min_size))
return buffer->buf;
uint32_t new_size = (buffer->size == 0) ? 4096 : buffer->size;
while (new_size < min_size) {
new_size *= 2;
}
void *ptr = SCRealloc(buffer->buf, new_size);
if (ptr != NULL) {
buffer->buf = ptr;
buffer->size = new_size;
} else {
return NULL;
}
return buffer->buf;
}
void SCInspectionBufferTruncate(InspectionBuffer *buffer, uint32_t buf_len)
{
DEBUG_VALIDATE_BUG_ON(buffer->buf == NULL);
DEBUG_VALIDATE_BUG_ON(buf_len > buffer->size);
buffer->inspect = buffer->buf;
buffer->inspect_len = buf_len;
buffer->initialized = true;
}
void InspectionBufferCopy(InspectionBuffer *buffer, uint8_t *buf, uint32_t buf_len)
{
SCInspectionBufferCheckAndExpand(buffer, buf_len);
if (buffer->size) {
uint32_t copy_size = MIN(buf_len, buffer->size);
memcpy(buffer->buf, buf, copy_size);
buffer->inspect = buffer->buf;
buffer->inspect_len = copy_size;
buffer->initialized = true;
}
}