/**
* Allocates aligned memory (for use with reads from raw/O_DIRECT devices).
* This memory must be freed with dvdalign_free()
* The size of the memory that is allocate is num_lbs*2048 bytes.
* The memory will be suitably aligned for use with
* block reads from raw/O_DIRECT device.
* @param num_lbs Number of logical blocks (2048 bytes) to allocate.
* @return Returns pointer to allocated memory, or NULL on failure
* This isn't supposed to be fast/efficient, if that is needed
* this function should be rewritten to use posix_memalign or similar.
* It's just needed for aligning memory for small block reads from
* raw/O_DIRECT devices.
* We assume that 2048 is enough alignment for all systems at the moment.
* Not thread safe. Only use this from one thread.
* Depends on sizeof(unsigned long) being at least as large as sizeof(void *)
*/
static void *dvdalign_lbmalloc(dvd_reader_t *device, uint32_t num_lbs)
{
void *m;
int n;
dvdalign_t *a;
m = malloc((num_lbs+1)*DVD_VIDEO_LB_LEN);
if(m == NULL) {
return m;
}
a = (dvdalign_t *)GetAlignHandle(device);
if(a == NULL) {
a = malloc(sizeof(dvdalign_t));
if(a == NULL) {
return a;
}
a->ptrs = NULL;
a->ptrs_in_use = 0;
a->ptrs_max = 0;
SetAlignHandle(device, (void *)a);
}
if(a->ptrs_in_use >= a->ptrs_max) {
a->ptrs = realloc(a->ptrs, (a->ptrs_max+10)*sizeof(dvdalign_ptrs_t));
if(a->ptrs == NULL) {
free(m);
return NULL;
}
a->ptrs_max+=10;
for(n = a->ptrs_in_use; n < a->ptrs_max; n++) {
a->ptrs[n].start = NULL;
a->ptrs[n].aligned = NULL;
}
n = a->ptrs_in_use;
} else {
for(n = 0; n < a->ptrs_max; n++) {
if(a->ptrs[n].start == NULL) {
break;
}
}
}
a->ptrs[n].start = m;
a->ptrs[n].aligned = DVD_ALIGN(m);
a->ptrs_in_use++;
/* If this function starts to be used too much print a warning.
Either there is a memory leak somewhere or we need to rewrite this to
a more efficient version.
*/
return a->ptrs[n].aligned;
}
ssize_t DVDReadBytes( dvd_file_t *dvd_file, void *data, size_t byte_size )
{
unsigned char *secbuf_start;
unsigned char *secbuf; //must be aligned to 2048-bytes for raw/O_DIRECT
unsigned int numsec, seek_sector, seek_byte;
int ret;
/* Check arguments. */
if( dvd_file == NULL || data == NULL ) {
errno = EINVAL;
return -1;
}
seek_sector = dvd_file->seek_pos / DVD_VIDEO_LB_LEN;
seek_byte = dvd_file->seek_pos % DVD_VIDEO_LB_LEN;
numsec = ( ( seek_byte + byte_size ) / DVD_VIDEO_LB_LEN ) +
( ( ( seek_byte + byte_size ) % DVD_VIDEO_LB_LEN ) ? 1 : 0 );
/* must align to 2048 bytes if we are reading from raw/O_DIRECT */
secbuf_start = (unsigned char *) malloc( (numsec+1) * DVD_VIDEO_LB_LEN );
if( !secbuf_start ) {
/* errno will be set to ENOMEM by malloc */
return -1;
}
secbuf = DVD_ALIGN(secbuf_start);
if( dvd_file->dvd->isImageFile ) {
ret = DVDReadBlocksUDF( dvd_file, (uint32_t) seek_sector,
(size_t) numsec, secbuf, DVDINPUT_NOFLAGS );
} else {
ret = DVDReadBlocksPath( dvd_file, seek_sector,
(size_t) numsec, secbuf, DVDINPUT_NOFLAGS );
}
if( ret != (int) numsec ) {
free( secbuf_start );
return ret < 0 ? ret : 0;
}
memcpy( data, &(secbuf[ seek_byte ]), byte_size );
free( secbuf_start );
dvd_file->seek_pos += byte_size;
return byte_size;
}
int DVDISOVolumeInfo( dvd_reader_t *dvd,
char *volid, unsigned int volid_size,
unsigned char *volsetid, unsigned int volsetid_size )
{
unsigned char *buffer; /* must be aligned to 2048 for raw/O_DIRECT */
unsigned char *buffer_start;
int ret;
/* Check arguments. */
if( dvd == NULL ) {
errno = EINVAL;
return -1;
}
if( dvd->dev == NULL ) {
/* No block access, so no ISO... */
errno = EINVAL;
return -1;
}
buffer_start = malloc( 2 * DVD_VIDEO_LB_LEN );
if( buffer_start == NULL ) {
return -1;
}
buffer = DVD_ALIGN(buffer_start);
ret = UDFReadBlocksRaw( dvd, 16, 1, buffer, 0 );
if( ret != 1 ) {
if(dvd->verbose >= 1) {
fprintf( stderr, "libdvdread: DVDISOVolumeInfo, failed to "
"read ISO9660 Primary Volume Descriptor!\n" );
}
free(buffer_start);
return -1;
}
if( (volid != NULL) && (volid_size > 0) ) {
unsigned int n;
for(n = 0; n < 32; n++) {
if(buffer[40+n] == 0x20) {
break;
}
}
if(volid_size > n+1) {
volid_size = n+1;
}
memcpy(volid, &buffer[40], volid_size-1);
volid[volid_size-1] = '\0';
}
if( (volsetid != NULL) && (volsetid_size > 0) ) {
if(volsetid_size > 128) {
volsetid_size = 128;
}
memcpy(volsetid, &buffer[190], volsetid_size);
}
free(buffer_start);
return 0;
}
