denyhosts/clamav/libclamav/libmspack.c

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/*
* Author: Sebastian Andrzej Siewior
* Summary: Glue code for libmspack handling.
*
* Acknowledgements: ClamAV uses Stuart Caie's libmspack to parse as number of
* Microsoft file formats.
* sebastian @ breakpoint ̣cc
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <mspack.h>
#include "clamav.h"
#include "fmap.h"
#include "scanners.h"
#include "others.h"
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#include "clamav_rust.h"
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enum mspack_type {
FILETYPE_DUNNO,
FILETYPE_FMAP,
FILETYPE_FILENAME,
};
struct mspack_name {
fmap_t *fmap;
off_t org;
};
struct mspack_system_ex {
struct mspack_system ops;
uint64_t max_size;
};
struct mspack_handle {
enum mspack_type type;
fmap_t *fmap;
off_t org;
off_t offset;
FILE *f;
uint64_t max_size;
};
static struct mspack_file *mspack_fmap_open(struct mspack_system *self,
const char *filename, int mode)
{
struct mspack_name *mspack_name;
struct mspack_handle *mspack_handle;
struct mspack_system_ex *self_ex;
const char *fmode;
const struct mspack_system *mptr = self;
if (!filename) {
cli_dbgmsg("%s() failed at %d\n", __func__, __LINE__);
return NULL;
}
mspack_handle = malloc(sizeof(*mspack_handle));
memset(mspack_handle, 0, (sizeof(*mspack_handle)));
if (!mspack_handle) {
cli_dbgmsg("%s() failed at %d\n", __func__, __LINE__);
return NULL;
}
memset(mspack_handle, 0, sizeof(*mspack_handle));
switch (mode) {
case MSPACK_SYS_OPEN_READ:
mspack_handle->type = FILETYPE_FMAP;
mspack_name = (struct mspack_name *)filename;
mspack_handle->fmap = mspack_name->fmap;
mspack_handle->org = mspack_name->org;
mspack_handle->offset = 0;
return (struct mspack_file *)mspack_handle;
case MSPACK_SYS_OPEN_WRITE:
fmode = "wb";
break;
case MSPACK_SYS_OPEN_UPDATE:
fmode = "r+b";
break;
case MSPACK_SYS_OPEN_APPEND:
fmode = "ab";
break;
default:
cli_dbgmsg("%s() wrong mode\n", __func__);
goto out_err;
}
mspack_handle->type = FILETYPE_FILENAME;
mspack_handle->f = fopen(filename, fmode);
if (!mspack_handle->f) {
cli_dbgmsg("%s() failed %d\n", __func__, __LINE__);
goto out_err;
}
self_ex = (struct mspack_system_ex *)((char *)mptr - offsetof(struct mspack_system_ex, ops));
mspack_handle->max_size = self_ex->max_size;
return (struct mspack_file *)mspack_handle;
out_err:
memset(mspack_handle, 0, (sizeof(*mspack_handle)));
free(mspack_handle);
mspack_handle = NULL;
return NULL;
}
static void mspack_fmap_close(struct mspack_file *file)
{
struct mspack_handle *mspack_handle = (struct mspack_handle *)file;
if (!mspack_handle)
return;
if (mspack_handle->type == FILETYPE_FILENAME)
if (mspack_handle->f)
fclose(mspack_handle->f);
memset(mspack_handle, 0, (sizeof(*mspack_handle)));
free(mspack_handle);
mspack_handle = NULL;
return;
}
static int mspack_fmap_read(struct mspack_file *file, void *buffer, int bytes)
{
struct mspack_handle *mspack_handle = (struct mspack_handle *)file;
off_t offset;
size_t count;
int ret;
if (bytes < 0) {
cli_dbgmsg("%s() %d\n", __func__, __LINE__);
return -1;
}
if (!mspack_handle) {
cli_dbgmsg("%s() %d\n", __func__, __LINE__);
return -1;
}
if (mspack_handle->type == FILETYPE_FMAP) {
/* Use fmap */
offset = mspack_handle->offset + mspack_handle->org;
count = fmap_readn(mspack_handle->fmap, buffer, (size_t)offset, (size_t)bytes);
if (count == (size_t)-1) {
cli_dbgmsg("%s() %d requested %d bytes, read failed (-1)\n", __func__, __LINE__, bytes);
return -1;
} else if ((int)count < bytes) {
cli_dbgmsg("%s() %d requested %d bytes, read %zu bytes\n", __func__, __LINE__, bytes, count);
}
mspack_handle->offset += (off_t)count;
return (int)count;
} else {
/* Use file descriptor */
count = fread(buffer, bytes, 1, mspack_handle->f);
if (count < 1) {
cli_dbgmsg("%s() %d requested %d bytes, read failed (%zu)\n", __func__, __LINE__, bytes, count);
return -1;
}
ret = (int)count;
return ret;
}
}
static int mspack_fmap_write(struct mspack_file *file, void *buffer, int bytes)
{
struct mspack_handle *mspack_handle = (struct mspack_handle *)file;
size_t count;
uint64_t max_size;
if (bytes < 0 || !mspack_handle) {
cli_dbgmsg("%s() err %d\n", __func__, __LINE__);
return -1;
}
if (mspack_handle->type == FILETYPE_FMAP) {
cli_dbgmsg("%s() err %d\n", __func__, __LINE__);
return -1;
}
if (!bytes)
return 0;
max_size = mspack_handle->max_size;
if (!max_size)
return bytes;
max_size = max_size < (uint64_t)bytes ? max_size : (uint64_t)bytes;
mspack_handle->max_size -= max_size;
count = fwrite(buffer, max_size, 1, mspack_handle->f);
if (count < 1) {
cli_dbgmsg("%s() err %d <%zu %d>\n", __func__, __LINE__, count, bytes);
return -1;
}
return bytes;
}
static int mspack_fmap_seek(struct mspack_file *file, off_t offset, int mode)
{
struct mspack_handle *mspack_handle = (struct mspack_handle *)file;
if (!mspack_handle) {
cli_dbgmsg("%s() err %d\n", __func__, __LINE__);
return -1;
}
if (mspack_handle->type == FILETYPE_FMAP) {
off_t new_pos;
switch (mode) {
case MSPACK_SYS_SEEK_START:
new_pos = offset;
break;
case MSPACK_SYS_SEEK_CUR:
new_pos = mspack_handle->offset + offset;
break;
case MSPACK_SYS_SEEK_END:
new_pos = mspack_handle->fmap->len + offset;
break;
default:
cli_dbgmsg("%s() err %d\n", __func__, __LINE__);
return -1;
}
if (new_pos < 0 || new_pos > (off_t)mspack_handle->fmap->len) {
cli_dbgmsg("%s() err %d\n", __func__, __LINE__);
return -1;
}
mspack_handle->offset = new_pos;
return 0;
}
switch (mode) {
case MSPACK_SYS_SEEK_START:
mode = SEEK_SET;
break;
case MSPACK_SYS_SEEK_CUR:
mode = SEEK_CUR;
break;
case MSPACK_SYS_SEEK_END:
mode = SEEK_END;
break;
default:
cli_dbgmsg("%s() err %d\n", __func__, __LINE__);
return -1;
}
return fseek(mspack_handle->f, offset, mode);
}
static off_t mspack_fmap_tell(struct mspack_file *file)
{
struct mspack_handle *mspack_handle = (struct mspack_handle *)file;
if (!mspack_handle)
return -1;
if (mspack_handle->type == FILETYPE_FMAP)
return mspack_handle->offset;
return (off_t)ftell(mspack_handle->f);
}
static void mspack_fmap_message(struct mspack_file *file, const char *fmt, ...)
{
UNUSEDPARAM(file);
if (UNLIKELY(cli_debug_flag)) {
va_list args;
char buff[BUFSIZ];
size_t len = sizeof("LibClamAV debug: ") - 1;
memset(buff, 0, BUFSIZ);
/* Add the prefix */
strncpy(buff, "LibClamAV debug: ", len);
va_start(args, fmt);
vsnprintf(buff + len, sizeof(buff) - len - 2, fmt, args);
va_end(args);
/* Add a newline and a null terminator */
buff[strlen(buff)] = '\n';
buff[strlen(buff) + 1] = '\0';
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clrs_eprint(buff);
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}
}
static void *mspack_fmap_alloc(struct mspack_system *self, size_t num)
{
UNUSEDPARAM(self);
void *addr = malloc(num);
if (addr) {
memset(addr, 0, num);
}
return addr;
}
static void mspack_fmap_free(void *mem)
{
if (mem) {
free(mem);
mem = NULL;
}
return;
}
static void mspack_fmap_copy(void *src, void *dst, size_t num)
{
memcpy(dst, src, num);
}
static struct mspack_system mspack_sys_fmap_ops = {
.open = mspack_fmap_open,
.close = mspack_fmap_close,
.read = mspack_fmap_read,
.write = mspack_fmap_write,
.seek = mspack_fmap_seek,
.tell = mspack_fmap_tell,
.message = mspack_fmap_message,
.alloc = mspack_fmap_alloc,
.free = mspack_fmap_free,
.copy = mspack_fmap_copy,
};
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cl_error_t cli_scanmscab(cli_ctx *ctx, off_t sfx_offset)
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{
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cl_error_t ret = CL_SUCCESS;
struct mscab_decompressor *cab_d = NULL;
struct mscabd_cabinet *cab_h = NULL;
struct mscabd_file *cab_f = NULL;
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int files;
struct mspack_name mspack_fmap = {
.fmap = ctx->fmap,
.org = sfx_offset,
};
struct mspack_system_ex ops_ex;
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char *tmp_fname = NULL;
bool tempfile_exists = false;
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memset(&ops_ex, 0, sizeof(struct mspack_system_ex));
ops_ex.ops = mspack_sys_fmap_ops;
cab_d = mspack_create_cab_decompressor(&ops_ex.ops);
if (!cab_d) {
cli_dbgmsg("%s() failed at %d\n", __func__, __LINE__);
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ret = CL_EUNPACK;
goto done;
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}
cab_d->set_param(cab_d, MSCABD_PARAM_FIXMSZIP, 1);
#if MSCABD_PARAM_SALVAGE
cab_d->set_param(cab_d, MSCABD_PARAM_SALVAGE, 1);
#endif
cab_h = cab_d->open(cab_d, (char *)&mspack_fmap);
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if (NULL == cab_h) {
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cli_dbgmsg("%s() failed at %d\n", __func__, __LINE__);
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ret = CL_EFORMAT;
goto done;
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}
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files = 0;
for (cab_f = cab_h->files; cab_f; cab_f = cab_f->next) {
uint64_t max_size;
ret = cli_matchmeta(ctx, cab_f->filename, 0, cab_f->length, 0,
files, 0, NULL);
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if (CL_SUCCESS != ret) {
goto done;
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}
if (ctx->engine->maxscansize) {
if (ctx->scansize >= ctx->engine->maxscansize) {
ret = CL_CLEAN;
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goto done;
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}
}
if (ctx->engine->maxfilesize > 0) {
// max filesize has been set
if ((ctx->engine->maxscansize > 0) &&
(ctx->scansize + ctx->engine->maxfilesize >= ctx->engine->maxscansize)) {
// ... but would exceed max scansize, shrink it.
max_size = ctx->engine->maxscansize - ctx->scansize;
} else {
// ... and will work
max_size = ctx->engine->maxfilesize;
}
} else {
// max filesize not specified
if ((ctx->engine->maxscansize > 0) &&
(ctx->scansize + UINT32_MAX >= ctx->engine->maxscansize)) {
// ... but UINT32_MAX would exceed max scansize, shrink it.
max_size = ctx->engine->maxscansize - ctx->scansize;
} else {
// ... use UINT32_MAX
max_size = UINT32_MAX;
}
}
tmp_fname = cli_gentemp(ctx->sub_tmpdir);
if (!tmp_fname) {
ret = CL_EMEM;
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goto done;
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}
ops_ex.max_size = max_size;
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/* scan */
ret = cab_d->extract(cab_d, cab_f, tmp_fname);
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if (ret) {
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/* Failed to extract. Try to scan what is there */
cli_dbgmsg("%s() failed to extract %d\n", __func__, ret);
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}
tempfile_exists = true; // probably
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ret = cli_magic_scan_file(tmp_fname, ctx, cab_f->filename, LAYER_ATTRIBUTES_NONE);
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if (CL_EOPEN == ret) {
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// okay so the file didn't actually get extracted. That's okay, we'll move on.
tempfile_exists = false;
ret = CL_SUCCESS;
} else if (CL_SUCCESS != ret) {
goto done;
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}
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if (!ctx->engine->keeptmp && tempfile_exists) {
if (cli_unlink(tmp_fname)) {
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ret = CL_EUNLINK;
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goto done;
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}
}
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free(tmp_fname);
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tmp_fname = NULL;
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files++;
}
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done:
if (NULL != tmp_fname) {
if (!ctx->engine->keeptmp && tempfile_exists) {
(void)cli_unlink(tmp_fname);
}
free(tmp_fname);
}
if (NULL != cab_d) {
if (NULL != cab_h) {
cab_d->close(cab_d, cab_h);
}
mspack_destroy_cab_decompressor(cab_d);
}
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return ret;
}
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cl_error_t cli_scanmschm(cli_ctx *ctx)
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{
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cl_error_t ret = CL_SUCCESS;
struct mschm_decompressor *mschm_d = NULL;
struct mschmd_header *mschm_h = NULL;
struct mschmd_file *mschm_f = NULL;
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int files;
struct mspack_name mspack_fmap = {
.fmap = ctx->fmap,
};
struct mspack_system_ex ops_ex;
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char *tmp_fname = NULL;
bool tempfile_exists = false;
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memset(&ops_ex, 0, sizeof(struct mspack_system_ex));
ops_ex.ops = mspack_sys_fmap_ops;
mschm_d = mspack_create_chm_decompressor(&ops_ex.ops);
if (!mschm_d) {
cli_dbgmsg("%s() failed at %d\n", __func__, __LINE__);
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ret = CL_EUNPACK;
goto done;
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}
mschm_h = mschm_d->open(mschm_d, (char *)&mspack_fmap);
if (!mschm_h) {
cli_dbgmsg("%s() failed at %d\n", __func__, __LINE__);
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ret = CL_EFORMAT;
goto done;
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}
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files = 0;
for (mschm_f = mschm_h->files; mschm_f; mschm_f = mschm_f->next) {
uint64_t max_size;
ret = cli_matchmeta(ctx, mschm_f->filename, 0, mschm_f->length,
0, files, 0, NULL);
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if (CL_SUCCESS != ret) {
goto done;
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}
if (ctx->engine->maxscansize) {
if (ctx->scansize >= ctx->engine->maxscansize) {
ret = CL_CLEAN;
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goto done;
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}
}
if (ctx->engine->maxfilesize > 0) {
// max filesize has been set
if ((ctx->engine->maxscansize > 0) &&
(ctx->scansize + ctx->engine->maxfilesize >= ctx->engine->maxscansize)) {
// ... but would exceed max scansize, shrink it.
max_size = ctx->engine->maxscansize - ctx->scansize;
} else {
// ... and will work
max_size = ctx->engine->maxfilesize;
}
} else {
// max filesize not specified
if ((ctx->engine->maxscansize > 0) &&
(ctx->scansize + UINT32_MAX >= ctx->engine->maxscansize)) {
// ... but UINT32_MAX would exceed max scansize, shrink it.
max_size = ctx->engine->maxscansize - ctx->scansize;
} else {
// ... use UINT32_MAX
max_size = UINT32_MAX;
}
}
tmp_fname = cli_gentemp(ctx->sub_tmpdir);
if (!tmp_fname) {
ret = CL_EMEM;
break;
}
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ops_ex.max_size = max_size;
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/* scan */
ret = mschm_d->extract(mschm_d, mschm_f, tmp_fname);
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if (ret) {
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/* Failed to extract. Try to scan what is there */
cli_dbgmsg("%s() failed to extract %d\n", __func__, ret);
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}
tempfile_exists = true; // probably
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ret = cli_magic_scan_file(tmp_fname, ctx, mschm_f->filename, LAYER_ATTRIBUTES_NONE);
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if (CL_EOPEN == ret) {
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// okay so the file didn't actually get extracted. That's okay, we'll move on.
tempfile_exists = false;
ret = CL_SUCCESS;
} else if (CL_SUCCESS != ret) {
goto done;
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}
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if (!ctx->engine->keeptmp && tempfile_exists) {
if (cli_unlink(tmp_fname)) {
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ret = CL_EUNLINK;
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goto done;
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}
}
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free(tmp_fname);
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tmp_fname = NULL;
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files++;
}
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done:
if (NULL != tmp_fname) {
if (!ctx->engine->keeptmp && tempfile_exists) {
(void)cli_unlink(tmp_fname);
}
free(tmp_fname);
}
if (NULL != mschm_d) {
if (NULL != mschm_h) {
mschm_d->close(mschm_d, mschm_h);
}
mspack_destroy_chm_decompressor(mschm_d);
}
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return ret;
}