static int fewf_pread(disk_t *disk, void *buffer, const unsigned int count, const uint64_t offset)
{
struct info_fewf_struct *data=(struct info_fewf_struct *)disk->data;
int64_t taille;
#if defined( HAVE_LIBEWF_V2_API )
taille = libewf_handle_read_random(
data->handle,
buffer,
count,
offset,
NULL );
#else
taille=libewf_read_random(data->handle, buffer, count, offset);
#endif
if(taille!=count)
{
log_error("fewf_pread(xxx,%u,buffer,%lu(%u/%u/%u)) read err: ",
(unsigned)(count/disk->sector_size), (long unsigned)(offset/disk->sector_size),
offset2cylinder(disk,offset), offset2head(disk,offset), offset2sector(disk,offset));
if(taille<0)
log_error("%s\n", strerror(errno));
else if(taille==0)
log_error("read after end of file\n");
else
log_error("Partial read\n");
if(taille<=0)
return -1;
}
return taille;
}
static ssize_t
ewf_image_read(TSK_IMG_INFO * img_info, TSK_OFF_T offset, char *buf,
size_t len)
{
#if defined( HAVE_LIBEWF_V2_API )
char error_string[TSK_EWF_ERROR_STRING_SIZE];
libewf_error_t *ewf_error = NULL;
#endif
ssize_t cnt;
IMG_EWF_INFO *ewf_info = (IMG_EWF_INFO *) img_info;
if (tsk_verbose)
tsk_fprintf(stderr,
"ewf_image_read: byte offset: %" PRIuOFF " len: %" PRIuSIZE
"\n", offset, len);
if (offset > img_info->size) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_IMG_READ_OFF);
tsk_error_set_errstr("ewf_image_read - %" PRIuOFF, offset);
return -1;
}
tsk_take_lock(&(ewf_info->read_lock));
#if defined( HAVE_LIBEWF_V2_API )
cnt = libewf_handle_read_random(ewf_info->handle,
buf, len, offset, &ewf_error);
if (cnt < 0) {
char *errmsg = NULL;
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_IMG_READ);
if (getError(ewf_error, error_string))
errmsg = strerror(errno);
else
errmsg = error_string;
tsk_error_set_errstr("ewf_image_read - offset: %" PRIuOFF
" - len: %" PRIuSIZE " - %s", offset, len, errmsg);
tsk_release_lock(&(ewf_info->read_lock));
return -1;
}
#else
cnt = libewf_read_random(ewf_info->handle, buf, len, offset);
if (cnt < 0) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_IMG_READ);
tsk_error_set_errstr("ewf_image_read - offset: %" PRIuOFF
" - len: %" PRIuSIZE " - %s", offset, len, strerror(errno));
tsk_release_lock(&(ewf_info->read_lock));
return -1;
}
#endif
tsk_release_lock(&(ewf_info->read_lock));
return cnt;
}
/* Reads a buffer of media data at a specific offset from EWF file(s)
* Returns a Python object holding the data if successful or NULL on error
*/
PyObject *pyewf_handle_read_random(
pyewf_handle_t *pyewf_handle,
PyObject *arguments,
PyObject *keywords )
{
char error_string[ PYEWF_ERROR_STRING_SIZE ];
liberror_error_t *error = NULL;
PyObject *result_data = NULL;
static char *function = "pyewf_handle_read_random";
static char *keyword_list[] = { "size", "offset", NULL };
off64_t read_offset = 0;
ssize_t read_count = 0;
int read_size = 0;
if( pyewf_handle == NULL )
{
PyErr_Format(
PyExc_TypeError,
"%s: invalid pyewf handle.",
function );
return( NULL );
}
if( pyewf_handle->handle == NULL )
{
PyErr_Format(
PyExc_TypeError,
"%s: invalid pyewf handle - missing libewf handle.",
function );
return( NULL );
}
if( PyArg_ParseTupleAndKeywords(
arguments,
keywords,
"i|L",
keyword_list,
&read_size,
&read_offset ) == 0 )
{
return( NULL );
}
if( read_size < 0 )
{
PyErr_Format(
PyExc_ValueError,
"%s: invalid argument read size value less than zero.",
function );
return( NULL );
}
/* Make sure the data fits into a memory buffer
*/
if( read_size > INT_MAX )
{
PyErr_Format(
PyExc_ValueError,
"%s: invalid argument read size value exceeds maximum.",
function );
return( NULL );
}
if( read_offset < 0 )
{
PyErr_Format(
PyExc_ValueError,
"%s: invalid argument read offset value less than zero.",
function );
return( NULL );
}
/* Make sure the data fits into a memory buffer
*/
result_data = PyString_FromStringAndSize(
NULL,
read_size );
read_count = libewf_handle_read_random(
pyewf_handle->handle,
PyString_AsString(
result_data ),
(size_t) read_size,
(off64_t) read_offset,
&error );
if( read_count != (ssize_t) read_size )
{
if( liberror_error_backtrace_sprint(
error,
error_string,
PYEWF_ERROR_STRING_SIZE ) == -1 )
{
PyErr_Format(
PyExc_IOError,
"%s: unable to read data.",
function );
}
else
{
PyErr_Format(
PyExc_IOError,
"%s: unable to read data.\n%s",
function,
error_string );
}
liberror_error_free(
&error );
return( NULL );
}
return( result_data );
}
