nkeynes@1099: /**
nkeynes@1099:  * $Id$
nkeynes@1099:  *
nkeynes@1099:  * ISO9660 filesystem reading support
nkeynes@1099:  *
nkeynes@1099:  * Copyright (c) 2010 Nathan Keynes.
nkeynes@1099:  *
nkeynes@1099:  * This program is free software; you can redistribute it and/or modify
nkeynes@1099:  * it under the terms of the GNU General Public License as published by
nkeynes@1099:  * the Free Software Foundation; either version 2 of the License, or
nkeynes@1099:  * (at your option) any later version.
nkeynes@1099:  *
nkeynes@1099:  * This program is distributed in the hope that it will be useful,
nkeynes@1099:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
nkeynes@1099:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nkeynes@1099:  * GNU General Public License for more details.
nkeynes@1099:  */
nkeynes@1099: 
nkeynes@1099: #include "drivers/cdrom/cdrom.h"
nkeynes@1099: #include "drivers/cdrom/isoread.h"
nkeynes@1099: #include "drivers/cdrom/iso_impl.h"
nkeynes@1099: 
nkeynes@1099: #include <string.h>
nkeynes@1099: #include <errno.h>
nkeynes@1099: 
nkeynes@1099: static char isofs_magic[5] = { 'C', 'D', '0', '0', '1' };
nkeynes@1099: 
nkeynes@1099: #define ISO_DIR_TAG 0x52494449
nkeynes@1099: 
nkeynes@1099: struct isofs_reader_dir {
nkeynes@1099:     uint32_t tag;
nkeynes@1099:     isofs_reader_dir_t parent;
nkeynes@1099:     size_t num_entries;
nkeynes@1099:     struct isofs_reader_dirent entries[];
nkeynes@1099: };
nkeynes@1099: 
nkeynes@1099: struct isofs_reader {
nkeynes@1099:     /**
nkeynes@1099:      * Base sector source to read the filesystem from (must support Mode 1 reads)
nkeynes@1099:      */
nkeynes@1099:     sector_source_t source;
nkeynes@1099: 
nkeynes@1099:     /**
nkeynes@1099:      * Offset of the source relative to the start of the (notional) disc -
nkeynes@1099:      * this is subtracted from all source lba addresses.
nkeynes@1099:      */
nkeynes@1099:     cdrom_lba_t source_offset;
nkeynes@1099: 
nkeynes@1099:     /**
nkeynes@1099:      * Start of the ISO9660 filesystem relative to the start of the disc.
nkeynes@1099:      * (The actual superblock is at fs_start+16)
nkeynes@1099:      */
nkeynes@1099:     cdrom_lba_t fs_start;
nkeynes@1099: 
nkeynes@1099:     /**
nkeynes@1099:      * If TRUE, read the little-endian side of the FS, otherwise the big-endian
nkeynes@1099:      * side. (They should normally give the same result, but in case it matters...)
nkeynes@1099:      */
nkeynes@1099:     gboolean little_endian;
nkeynes@1099: 
nkeynes@1099:     /**
nkeynes@1099:      * The volume sequence number, for multi-volume sets.
nkeynes@1099:      */
nkeynes@1099:     uint16_t volume_seq_no;
nkeynes@1099: 
nkeynes@1099:     char volume_label[33];
nkeynes@1099: 
nkeynes@1099:     /**
nkeynes@1099:      * Filesystem root directory
nkeynes@1099:      */
nkeynes@1099:     isofs_reader_dir_t root_dir;
nkeynes@1099: };
nkeynes@1099: 
nkeynes@1099: /**
nkeynes@1099:  * Read a 16-bit dual-endian field using the defined endianness of the reader
nkeynes@1099:  */
nkeynes@1099: #define ISO_GET_DE16( iso, field ) \
nkeynes@1099:     ( ((iso)->little_endian) ? GINT16_FROM_LE(field) : GINT16_FROM_BE(*((&field)+1)) )
nkeynes@1099: 
nkeynes@1099: /**
nkeynes@1099:  * Read a 32-bit dual-endian field using the defined endianness of the reader
nkeynes@1099:  */
nkeynes@1099: #define ISO_GET_DE32( iso, field ) \
nkeynes@1099:     ( ((iso)->little_endian) ? GINT32_FROM_LE(field) : GINT32_FROM_BE(*((&field)+1)) )
nkeynes@1099: 
nkeynes@1099: 
nkeynes@1099: static void isofs_reader_convert_dirent( isofs_reader_t iso, isofs_reader_dirent_t dest, iso_dirent_t src,
nkeynes@1099:                                          char **strp )
nkeynes@1099: {
nkeynes@1099:     dest->start_lba = ISO_GET_DE32(iso, src->file_lba_le);
nkeynes@1099:     dest->size = ISO_GET_DE32(iso, src->file_size_le);
nkeynes@1099:     dest->is_dir = (src->flags & ISO_FILE_DIR) ? TRUE : FALSE;
nkeynes@1099:     dest->interleave_gap = src->gap_size;
nkeynes@1099:     dest->interleave_size = src->unit_size;
nkeynes@1099:     dest->name = *strp;
nkeynes@1099:     memcpy( *strp, src->file_id, src->file_id_len );
nkeynes@1099:     (*strp)[src->file_id_len] = '\0';
nkeynes@1099:     *strp += src->file_id_len + 1;
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: /**
nkeynes@1099:  * Read a directory from the disc into memory.
nkeynes@1099:  */
nkeynes@1099: isofs_reader_dir_t isofs_reader_read_dir( isofs_reader_t iso, cdrom_lba_t lba, size_t size )
nkeynes@1099: {
nkeynes@1099:     cdrom_count_t count = (size+2047)/2048;
nkeynes@1099: 
nkeynes@1099:     char buf[count*2048];
nkeynes@1099: 
nkeynes@1099:     if( isofs_reader_read_sectors( iso, lba, count, buf ) != CDROM_ERROR_OK )
nkeynes@1099:         return NULL;
nkeynes@1099: 
nkeynes@1099:     size_t len = 0;
nkeynes@1099:     unsigned num_entries = 0, i=0, offset=0;
nkeynes@1099:     /* Compute number of entries and total string length */
nkeynes@1099:     while( offset < size ) {
nkeynes@1099:         struct iso_dirent *p = (struct iso_dirent *)&buf[offset];
nkeynes@1099:         offset += p->record_len;
nkeynes@1099:         if( offset > size || p->record_len < sizeof(struct iso_dirent) )
nkeynes@1099:             break; // Bad record length
nkeynes@1099:         if( p->file_id_len + sizeof(struct iso_dirent)-1 > p->record_len )
nkeynes@1099:             break; // Bad fileid length
nkeynes@1099:         if( p->file_id_len == 1 && (p->file_id[0] == 0 || p->file_id[0] == 1 ) )
nkeynes@1099:             continue; /* self and parent-dir references */
nkeynes@1099:         num_entries++;
nkeynes@1099:         len += p->file_id_len + 1;
nkeynes@1099:     }
nkeynes@1099: 
nkeynes@1099:     size_t table_len = num_entries * sizeof(struct isofs_reader_dirent);
nkeynes@1099:     isofs_reader_dir_t dir = g_malloc0( sizeof(struct isofs_reader_dir) + table_len + len );
nkeynes@1099:     dir->tag = ISO_DIR_TAG;
nkeynes@1099:     dir->num_entries = num_entries;
nkeynes@1099: 
nkeynes@1099:     char *strp = (char *)&dir->entries[num_entries];
nkeynes@1099:     offset = 0;
nkeynes@1099:     for( i=0; i < num_entries; i++ ) {
nkeynes@1099:         struct iso_dirent *p;
nkeynes@1099:         do {
nkeynes@1099:             p = (struct iso_dirent *)&buf[offset];
nkeynes@1099:             offset += p->record_len;
nkeynes@1099:             /* Skip over self and parent-dir references */
nkeynes@1099:         } while( p->file_id_len == 1 && (p->file_id[0] == 0 || p->file_id[0] == 1 ) );
nkeynes@1099: 
nkeynes@1099:         isofs_reader_convert_dirent( iso, &dir->entries[i], p, &strp );
nkeynes@1099: 
nkeynes@1099:     }
nkeynes@1099:     return dir;
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: static gboolean isofs_reader_dirent_match_exact( const char *file, const char *find )
nkeynes@1099: {
nkeynes@1099:     return strcasecmp( file, find ) == 0;
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: static gboolean isofs_reader_dirent_match_unversioned( const char *file, const char *find )
nkeynes@1099: {
nkeynes@1099:     char *semi = strchr(file, ';');
nkeynes@1099:     if( semi == NULL ) {
nkeynes@1099:         /* Unversioned ISO file */
nkeynes@1099:         return strcasecmp( file, find ) == 0;
nkeynes@1099:     } else {
nkeynes@1099:         int len = semi - file;
nkeynes@1099:         return strncasecmp( file, find, len ) == 0 && strlen(find) == len;
nkeynes@1099:     }
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: /**
nkeynes@1099:  * Search a directory for a given filename. If found, return the corresponding
nkeynes@1099:  * dirent structure, otherwise NULL. Comparison is case-insensitive, and returns
nkeynes@1099:  * the most recent (highest numbered) version of a file in case of multiple
nkeynes@1099:  * versions unless the requested component is also explicitly versioned.
nkeynes@1099:  *
nkeynes@1099:  * For now just do a linear search, although we could do a binary search given
nkeynes@1099:  * that the directory should be sorted.
nkeynes@1099:  */
nkeynes@1099: static isofs_reader_dirent_t isofs_reader_get_file_component( isofs_reader_dir_t dir, const char *component )
nkeynes@1099: {
nkeynes@1099: 
nkeynes@1099:     if( strchr( component, ';' ) != NULL ) {
nkeynes@1099:         for( unsigned i=0; i<dir->num_entries; i++ ) {
nkeynes@1099:             if( isofs_reader_dirent_match_exact(dir->entries[i].name,component) ) {
nkeynes@1099:                 return &dir->entries[i];
nkeynes@1099:             }
nkeynes@1099:         }
nkeynes@1099:     } else {
nkeynes@1099:         for( unsigned i=0; i<dir->num_entries; i++ ) {
nkeynes@1099:             if( isofs_reader_dirent_match_unversioned(dir->entries[i].name,component) ) {
nkeynes@1099:                 return &dir->entries[i];
nkeynes@1099:             }
nkeynes@1099:         }
nkeynes@1099:     }
nkeynes@1099:     return NULL;
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: isofs_reader_dirent_t isofs_reader_get_file( isofs_reader_t iso, const char *pathname )
nkeynes@1099: {
nkeynes@1099:     int pathlen = strlen(pathname);
nkeynes@1099:     char tmp[pathlen+1];
nkeynes@1099:     char *p = tmp;
nkeynes@1099:     isofs_reader_dir_t dir = iso->root_dir;
nkeynes@1099: 
nkeynes@1099:     memcpy( tmp, pathname, pathlen+1 );
nkeynes@1099:     char *q = strchr(p, '/');
nkeynes@1099:     while( q != NULL ) {
nkeynes@1099:         *q = '\0';
nkeynes@1099:         isofs_reader_dirent_t ent = isofs_reader_get_file_component( dir, p );
nkeynes@1099:         if( ent == NULL || !ent->is_dir ) {
nkeynes@1099:             return NULL;
nkeynes@1099:         }
nkeynes@1099:         if( ent->subdir == NULL ) {
nkeynes@1099:             ent->subdir = dir = isofs_reader_read_dir( iso, ent->start_lba, ent->size );
nkeynes@1099:             if( dir == NULL ) {
nkeynes@1099:                 return NULL;
nkeynes@1099:             }
nkeynes@1099:         }
nkeynes@1099: 
nkeynes@1099:         p = q+1;
nkeynes@1099:         q = strchr(p, '/');
nkeynes@1099: 
nkeynes@1099:     }
nkeynes@1099:     return isofs_reader_get_file_component( dir, p );
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: cdrom_error_t isofs_reader_read_file( isofs_reader_t iso, isofs_reader_dirent_t file,
nkeynes@1099:                                       size_t offset, size_t byte_count, unsigned char *buf )
nkeynes@1099: {
nkeynes@1099:     char tmp[2048];
nkeynes@1099: 
nkeynes@1099:     if( offset + byte_count > file->size )
nkeynes@1099:         return CDROM_ERROR_BADREAD;
nkeynes@1099: 
nkeynes@1099:     if( file->interleave_gap == 0 ) {
nkeynes@1099:         cdrom_lba_t lba = file->start_lba + (offset>>11);
nkeynes@1099:         lba += ((file->xa_size+2047)>>11); /* Skip XA record if present */
nkeynes@1099: 
nkeynes@1099:         if( (offset & 2047) != 0 ) {
nkeynes@1099:             /* Read an unaligned start block */
nkeynes@1099:             cdrom_error_t status = isofs_reader_read_sectors( iso, lba, 1, tmp );
nkeynes@1099:             if( status != CDROM_ERROR_OK )
nkeynes@1099:                 return status;
nkeynes@1099:             unsigned align = offset & 2047;
nkeynes@1099:             size_t length = 2048 - align;
nkeynes@1099:             if( length >= byte_count ) {
nkeynes@1099:                 memcpy( buf, &tmp[align], byte_count );
nkeynes@1099:                 return CDROM_ERROR_OK;
nkeynes@1099:             } else {
nkeynes@1099:                 memcpy( buf, &tmp[align], length );
nkeynes@1099:                 byte_count -= length;
nkeynes@1099:                 buf += length;
nkeynes@1099:                 lba++;
nkeynes@1099:             }
nkeynes@1099:         }
nkeynes@1099:         /* Read the bulk of the data */
nkeynes@1099:         cdrom_count_t sector_count = byte_count >> 11;
nkeynes@1099:         if( sector_count > 0 ) {
nkeynes@1099:             cdrom_error_t status = isofs_reader_read_sectors( iso, lba, sector_count, buf );
nkeynes@1099:             if( status != CDROM_ERROR_OK )
nkeynes@1099:                 return status;
nkeynes@1099:             buf += (sector_count << 11);
nkeynes@1099:             lba += sector_count;
nkeynes@1099:         }
nkeynes@1099:         /* Finally read a partial final block */
nkeynes@1099:         if( (byte_count & 2047) != 0 ) {
nkeynes@1099:             cdrom_error_t status = isofs_reader_read_sectors( iso, lba, 1, tmp );
nkeynes@1099:             if( status != CDROM_ERROR_OK )
nkeynes@1099:                 return status;
nkeynes@1099:             memcpy( buf, tmp, byte_count & 2047 );
nkeynes@1099:         }
nkeynes@1099:         return CDROM_ERROR_OK;
nkeynes@1099:     } else {
nkeynes@1099:         // ERROR("Interleaved files not supported");
nkeynes@1099:         return CDROM_ERROR_BADREAD;
nkeynes@1099:     }
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: void isofs_reader_destroy_dir( isofs_reader_dir_t dir )
nkeynes@1099: {
nkeynes@1099:     dir->tag = 0;
nkeynes@1099:     for( unsigned i=0; i<dir->num_entries; i++ ) {
nkeynes@1099:         if( dir->entries[i].subdir != NULL ) {
nkeynes@1099:             isofs_reader_dir_t subdir = dir->entries[i].subdir;
nkeynes@1099:             dir->entries[i].subdir = NULL;
nkeynes@1099:             isofs_reader_destroy_dir(dir);
nkeynes@1099:         }
nkeynes@1099:     }
nkeynes@1099:     g_free(dir);
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: cdrom_error_t isofs_reader_read_sectors( isofs_reader_t iso, cdrom_lba_t lba, cdrom_count_t count,
nkeynes@1099:                                          unsigned char *buf )
nkeynes@1099: {
nkeynes@1099:     if( lba < iso->source_offset )
nkeynes@1099:         return CDROM_ERROR_BADREAD;
nkeynes@1099:     return sector_source_read_sectors( iso->source, lba - iso->source_offset, count,
nkeynes@1099:            CDROM_READ_MODE2_FORM1|CDROM_READ_DATA, buf, NULL );
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: 
nkeynes@1099: isofs_reader_t isofs_reader_new( sector_source_t source, cdrom_lba_t offset, cdrom_lba_t start, ERROR *err )
nkeynes@1099: {
nkeynes@1099:     char buf[2048];
nkeynes@1099:     iso_pvd_t pvd = (iso_pvd_t)&buf;
nkeynes@1099:     unsigned i = 0;
nkeynes@1099: 
nkeynes@1099:     isofs_reader_t iso = g_malloc0( sizeof(struct isofs_reader) );
nkeynes@1099:     if( iso == NULL ) {
nkeynes@1099:         SET_ERROR( err, ENOMEM, "Unable to allocate memory" );
nkeynes@1099:         return NULL;
nkeynes@1099:     }
nkeynes@1099:     iso->source = source;
nkeynes@1099:     iso->source_offset = offset;
nkeynes@1099:     iso->fs_start = start;
nkeynes@1099:     iso->little_endian = TRUE;
nkeynes@1099: 
nkeynes@1099:     do {
nkeynes@1099:         /* Find the primary volume descriptor */
nkeynes@1099:         cdrom_error_t status = isofs_reader_read_sectors( iso, iso->fs_start + ISO_SUPERBLOCK_OFFSET + i, 1, buf );
nkeynes@1099:         if( status != CDROM_ERROR_OK ) {
nkeynes@1099:             SET_ERROR( err, EBADF, "Unable to read superblock from ISO9660 filesystem" );
nkeynes@1099:             g_free(iso);
nkeynes@1099:             return NULL;
nkeynes@1099:         }
nkeynes@1099:         if( memcmp(pvd->tag, isofs_magic, 5) != 0 || /* Not an ISO volume descriptor */
nkeynes@1099:                 pvd->desc_type == ISO_TERMINAL_DESCRIPTOR ) { /* Reached the end of the descriptor list */
nkeynes@1099:             SET_ERROR( err, EINVAL, "ISO9660 filesystem not found" );
nkeynes@1099:             g_free(iso);
nkeynes@1099:             return NULL;
nkeynes@1099:         }
nkeynes@1099:         i++;
nkeynes@1099:     } while( pvd->desc_type != ISO_PRIMARY_DESCRIPTOR );
nkeynes@1099: 
nkeynes@1099:     if( pvd->desc_version != 1 ) {
nkeynes@1099:         SET_ERROR( err, EINVAL, "Incompatible ISO9660 filesystem" );
nkeynes@1099:         g_free(iso);
nkeynes@1099:         return NULL;
nkeynes@1099:     }
nkeynes@1099: 
nkeynes@1099:     iso->volume_seq_no = ISO_GET_DE16(iso, pvd->volume_seq_le);
nkeynes@1099:     memcpy( iso->volume_label, pvd->volume_id, 32 );
nkeynes@1099:     for( i=32; i>0 && iso->volume_label[i-1] == ' '; i-- );
nkeynes@1099:     iso->volume_label[i] = '\0';
nkeynes@1099: 
nkeynes@1099:     iso->root_dir = isofs_reader_read_dir( iso,
nkeynes@1099:             ISO_GET_DE32(iso, pvd->root_dirent.file_lba_le),
nkeynes@1099:             ISO_GET_DE32(iso, pvd->root_dirent.file_size_le) );
nkeynes@1099:     if( iso->root_dir == NULL ) {
nkeynes@1099:         SET_ERROR( err, EINVAL, "Unable to read root directory from ISO9660 filesystem" );
nkeynes@1099:         g_free(iso);
nkeynes@1099:         return NULL;
nkeynes@1099:     }
nkeynes@1099: 
nkeynes@1099:     sector_source_ref( source );
nkeynes@1099:     return iso;
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: isofs_reader_t isofs_reader_new_from_disc( cdrom_disc_t disc, cdrom_lba_t lba, ERROR *err )
nkeynes@1099: {
nkeynes@1099:     return isofs_reader_new( &disc->source, 0, lba, err );
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: isofs_reader_t isofs_reader_new_from_track( cdrom_disc_t disc, cdrom_track_t track, ERROR *err )
nkeynes@1099: {
nkeynes@1099:     return isofs_reader_new( &disc->source, 0, track->lba, err );
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: isofs_reader_t isofs_reader_new_from_source( sector_source_t source, ERROR *err )
nkeynes@1099: {
nkeynes@1099:     return isofs_reader_new( source, 0, 0, err );
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: void isofs_reader_destroy( isofs_reader_t iso )
nkeynes@1099: {
nkeynes@1099:     isofs_reader_destroy_dir( iso->root_dir );
nkeynes@1099:     iso->root_dir = NULL;
nkeynes@1099:     sector_source_unref( iso->source );
nkeynes@1099:     iso->source = NULL;
nkeynes@1099:     g_free( iso );
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: isofs_reader_dir_t isofs_reader_get_root_dir( isofs_reader_t iso )
nkeynes@1099: {
nkeynes@1099:     return iso->root_dir;
nkeynes@1099: }
nkeynes@1099: 
nkeynes@1099: void isofs_reader_print_dir( FILE *f, isofs_reader_dir_t dir )
nkeynes@1099: {
nkeynes@1099:     fprintf( f, "Total %d files\n", dir->num_entries );
nkeynes@1099:     for( unsigned i=0; i<dir->num_entries; i++ ) {
nkeynes@1099:         fprintf( f, "%7d %s\n", dir->entries[i].size, dir->entries[i].name );
nkeynes@1099:     }
nkeynes@1099: 
nkeynes@1099: }