libdvdread/dvd_udf.c

   1 /* -*- c-basic-offset: 2; indent-tabs-mode: nil -*- */
   2 /*
   3  * This code is based on dvdudf by:
   4  *   Christian Wolff <scarabaeus@convergence.de>.
   5  *
   6  * Modifications by:
   7  *   Billy Biggs <vektor@dumbterm.net>.
   8  *   Björn Englund <d4bjorn@dtek.chalmers.se>.
   9  *
  10  * dvdudf: parse and read the UDF volume information of a DVD Video
  11  * Copyright (C) 1999 Christian Wolff for convergence integrated media
  12  * GmbH The author can be reached at scarabaeus@convergence.de, the
  13  * project's page is at http://linuxtv.org/dvd/
  14  *
  15  * This program is free software; you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2 of the License, or (at
  18  * your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful, but
  21  * WITHOUT ANY WARRANTY; without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  23  * General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program; if not, write to the Free Software
  27  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  28  * 02111-1307, USA.  Or, point your browser to
  29  * http://www.gnu.org/copyleft/gpl.html
  30  */
  31
  32 #include "config.h"
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37
  38 #include <sys/types.h>
  39 #include <sys/stat.h>
  40 #include <unistd.h>
  41 #include <errno.h>
  42
  43 #if defined(HAVE_INTTYPES_H)
  44 #include <inttypes.h>
  45 #elif defined(HAVE_STDINT_H)
  46 #include <stdint.h>
  47 #endif
  48
  49 #include "dvd_reader.h"
  50 #include "dvd_udf.h"
  51 #include "dvdread_internal.h"
  52
  53 #ifndef EMEDIUMTYPE
  54 #define EMEDIUMTYPE ENOENT
  55 #endif
  56
  57 #ifndef HAVE_UINTPTR_T
  58 #warning "Assuming that (unsigned long) can hold (void *)"
  59 typedef unsigned long uintptr_t;
  60 #endif
  61
  62 #define DVD_ALIGN(ptr) (void *)((((uintptr_t)(ptr)) + (DVD_VIDEO_LB_LEN-1)) \
  63                                 / DVD_VIDEO_LB_LEN * DVD_VIDEO_LB_LEN)
  64
  65 typedef struct {
  66   void *start;
  67   void *aligned;
  68 } dvdalign_ptrs_t;
  69
  70 typedef struct {
  71   dvdalign_ptrs_t *ptrs;
  72   uint32_t ptrs_in_use;
  73   uint32_t ptrs_max;
  74 } dvdalign_t;
  75
  76 extern void *GetAlignHandle(dvd_reader_t *device);
  77 extern void SetAlignHandle(dvd_reader_t *device, void *align);
  78
  79 /**
  80  * Allocates aligned memory (for use with reads from raw/O_DIRECT devices).
  81  * This memory must be freed with dvdalign_free()
  82  * The size of the memory that is allocate is num_lbs*2048 bytes.
  83  * The memory will be suitably aligned for use with
  84  * block reads from raw/O_DIRECT device.
  85  * @param num_lbs Number of logical blocks (2048 bytes) to allocate.
  86  * @return Returns pointer to allocated memory, or NULL on failure
  87  * This isn't supposed to be fast/efficient, if that is needed
  88  * this function should be rewritten to use posix_memalign or similar.
  89  * It's just needed for aligning memory for small block reads from
  90  * raw/O_DIRECT devices.
  91  * We assume that 2048 is enough alignment for all systems at the moment.
  92  * Not thread safe. Only use this from one thread.
  93  * Depends on sizeof(unsigned long) being at least as large as sizeof(void *)
  94  */
  95 static void *dvdalign_lbmalloc(dvd_reader_t *device, uint32_t num_lbs)
  96 {
  97   void *m;
  98   int n;
  99   dvdalign_t *a;
 100
 101   m = malloc((num_lbs+1)*DVD_VIDEO_LB_LEN);
 102   if(m == NULL) {
 103     return m;
 104   }
 105   a = (dvdalign_t *)GetAlignHandle(device);
 106   if(a == NULL) {
 107     a = malloc(sizeof(dvdalign_t));
 108     if(a == NULL) {
 109       return a;
 110     }
 111     a->ptrs = NULL;
 112     a->ptrs_in_use = 0;
 113     a->ptrs_max = 0;
 114     SetAlignHandle(device, (void *)a);
 115   }
 116
 117   if(a->ptrs_in_use >= a->ptrs_max) {
 118     a->ptrs = realloc(a->ptrs, (a->ptrs_max+10)*sizeof(dvdalign_ptrs_t));
 119     if(a->ptrs == NULL) {
 120       free(m);
 121       return NULL;
 122     }
 123     a->ptrs_max+=10;
 124     for(n = a->ptrs_in_use; n < a->ptrs_max; n++) {
 125       a->ptrs[n].start = NULL;
 126       a->ptrs[n].aligned = NULL;
 127     }
 128     n = a->ptrs_in_use;
 129   } else {
 130     for(n = 0; n < a->ptrs_max; n++) {
 131       if(a->ptrs[n].start == NULL) {
 132         break;
 133       }
 134     }
 135   }
 136
 137   a->ptrs[n].start = m;
 138   a->ptrs[n].aligned = DVD_ALIGN(m);
 139
 140   a->ptrs_in_use++;
 141
 142   /* If this function starts to be used too much print a warning.
 143      Either there is a memory leak somewhere or we need to rewrite this to
 144      a more efficient version.
 145   */
 146   if(a->ptrs_in_use > 50) {
 147     if(dvdread_verbose(device) >= 0) {
 148       fprintf(stderr, "libdvdread: dvdalign_lbmalloc(), more allocs than supposed: %u\n", a->ptrs_in_use);
 149     }
 150   }
 151
 152   return  a->ptrs[n].aligned;
 153 }
 154
 155 /**
 156  * Frees memory allocated with dvdalign_lbmemory()
 157  * @param ptr Pointer to memory space to free
 158  * Not thread safe.
 159  */
 160 static void dvdalign_lbfree(dvd_reader_t *device, void *ptr)
 161 {
 162   int n;
 163   dvdalign_t *a;
 164
 165   a = (dvdalign_t *)GetAlignHandle(device);
 166   if(a && a->ptrs) {
 167     for(n = 0; n < a->ptrs_max; n++) {
 168       if(a->ptrs[n].aligned == ptr) {
 169         free(a->ptrs[n].start);
 170         a->ptrs[n].start = NULL;
 171         a->ptrs[n].aligned = NULL;
 172         a->ptrs_in_use--;
 173         if(a->ptrs_in_use == 0) {
 174           free(a->ptrs);
 175           a->ptrs = NULL;
 176           a->ptrs_max = 0;
 177           free(a);
 178           a = NULL;
 179           SetAlignHandle(device, (void *)a);
 180         }
 181         return;
 182       }
 183     }
 184   }
 185   if(dvdread_verbose(device) >= 0) {
 186     fprintf(stderr, "libdvdread: dvdalign_lbfree(), error trying to free mem: %08lx (%u)\n", (unsigned long)ptr, a ? a->ptrs_in_use : 0);
 187   }
 188 }
 189
 190
 191 /* Private but located in/shared with dvd_reader.c */
 192 extern int UDFReadBlocksRaw( dvd_reader_t *device, uint32_t lb_number,
 193                              size_t block_count, unsigned char *data,
 194                              int encrypted );
 195
 196 /** @internal
 197  * Its required to either fail or deliver all the blocks asked for.
 198  *
 199  * @param data Pointer to a buffer where data is returned. This must be large
 200  *   enough to hold lb_number*2048 bytes.
 201  *   It must be aligned to system specific (2048) logical blocks size when
 202  *   reading from raw/O_DIRECT device.
 203  */
 204 static int DVDReadLBUDF( dvd_reader_t *device, uint32_t lb_number,
 205                          size_t block_count, unsigned char *data,
 206                          int encrypted )
 207 {
 208   int ret;
 209   size_t count = block_count;
 210
 211   while(count > 0) {
 212
 213     ret = UDFReadBlocksRaw(device, lb_number, count, data, encrypted);
 214
 215     if(ret <= 0) {
 216       /* One of the reads failed or nothing more to read, too bad.
 217        * We won't even bother returning the reads that went ok. */
 218       return ret;
 219     }
 220
 221     count -= (size_t)ret;
 222     lb_number += (uint32_t)ret;
 223   }
 224
 225   return block_count;
 226 }
 227
 228
 229 #ifndef NULL
 230 #define NULL ((void *)0)
 231 #endif
 232
 233 struct Partition {
 234   int valid;
 235   char VolumeDesc[128];
 236   uint16_t Flags;
 237   uint16_t Number;
 238   char Contents[32];
 239   uint32_t AccessType;
 240   uint32_t Start;
 241   uint32_t Length;
 242 };
 243
 244 struct AD {
 245   uint32_t Location;
 246   uint32_t Length;
 247   uint8_t  Flags;
 248   uint16_t Partition;
 249 };
 250
 251 struct extent_ad {
 252   uint32_t location;
 253   uint32_t length;
 254 };
 255
 256 struct avdp_t {
 257   struct extent_ad mvds;
 258   struct extent_ad rvds;
 259 };
 260
 261 struct pvd_t {
 262   uint8_t VolumeIdentifier[32];
 263   uint8_t VolumeSetIdentifier[128];
 264 };
 265
 266 struct lbudf {
 267   uint32_t lb;
 268   uint8_t *data;
 269 };
 270
 271 struct icbmap {
 272   uint32_t lbn;
 273   struct AD file;
 274   uint8_t filetype;
 275 };
 276
 277 struct udf_cache {
 278   int avdp_valid;
 279   struct avdp_t avdp;
 280   int pvd_valid;
 281   struct pvd_t pvd;
 282   int partition_valid;
 283   struct Partition partition;
 284   int rooticb_valid;
 285   struct AD rooticb;
 286   int lb_num;
 287   struct lbudf *lbs;
 288   int map_num;
 289   struct icbmap *maps;
 290 };
 291
 292 typedef enum {
 293   PartitionCache, RootICBCache, LBUDFCache, MapCache, AVDPCache, PVDCache
 294 } UDFCacheType;
 295
 296 extern void *GetUDFCacheHandle(dvd_reader_t *device);
 297 extern void SetUDFCacheHandle(dvd_reader_t *device, void *cache);
 298
 299
 300 void FreeUDFCache(dvd_reader_t *device, void *cache)
 301 {
 302   int n;
 303
 304   struct udf_cache *c = (struct udf_cache *)cache;
 305   if(c == NULL) {
 306     return;
 307   }
 308
 309   for(n = 0; n < c->lb_num; n++) {
 310     if(c->lbs[n].data) {
 311       /* free data */
 312       dvdalign_lbfree(device, c->lbs[n].data);
 313     }
 314   }
 315   c->lb_num = 0;
 316
 317   if(c->lbs) {
 318     free(c->lbs);
 319   }
 320   if(c->maps) {
 321     free(c->maps);
 322   }
 323   free(c);
 324 }
 325
 326
 327 static int GetUDFCache(dvd_reader_t *device, UDFCacheType type,
 328                        uint32_t nr, void *data)
 329 {
 330   int n;
 331   struct udf_cache *c;
 332
 333   if(DVDUDFCacheLevel(device, -1) <= 0) {
 334     return 0;
 335   }
 336
 337   c = (struct udf_cache *)GetUDFCacheHandle(device);
 338
 339   if(c == NULL) {
 340     return 0;
 341   }
 342
 343   switch(type) {
 344   case AVDPCache:
 345     if(c->avdp_valid) {
 346       *(struct avdp_t *)data = c->avdp;
 347       return 1;
 348     }
 349     break;
 350   case PVDCache:
 351     if(c->pvd_valid) {
 352       *(struct pvd_t *)data = c->pvd;
 353       return 1;
 354     }
 355     break;
 356   case PartitionCache:
 357     if(c->partition_valid) {
 358       *(struct Partition *)data = c->partition;
 359       return 1;
 360     }
 361     break;
 362   case RootICBCache:
 363     if(c->rooticb_valid) {
 364       *(struct AD *)data = c->rooticb;
 365       return 1;
 366     }
 367     break;
 368   case LBUDFCache:
 369     for(n = 0; n < c->lb_num; n++) {
 370       if(c->lbs[n].lb == nr) {
 371         *(uint8_t **)data = c->lbs[n].data;
 372         return 1;
 373       }
 374     }
 375     break;
 376   case MapCache:
 377     for(n = 0; n < c->map_num; n++) {
 378       if(c->maps[n].lbn == nr) {
 379         *(struct icbmap *)data = c->maps[n];
 380         return 1;
 381       }
 382     }
 383     break;
 384   default:
 385     break;
 386   }
 387
 388   return 0;
 389 }
 390
 391 static int SetUDFCache(dvd_reader_t *device, UDFCacheType type,
 392                        uint32_t nr, void *data)
 393 {
 394   int n;
 395   struct udf_cache *c;
 396
 397   if(DVDUDFCacheLevel(device, -1) <= 0) {
 398     return 0;
 399   }
 400
 401   c = (struct udf_cache *)GetUDFCacheHandle(device);
 402
 403   if(c == NULL) {
 404     c = calloc(1, sizeof(struct udf_cache));
 405     //    fprintf(stderr, "calloc: %d\n", sizeof(struct udf_cache));
 406     if(c == NULL) {
 407       return 0;
 408     }
 409     SetUDFCacheHandle(device, c);
 410   }
 411
 412
 413   switch(type) {
 414   case AVDPCache:
 415     c->avdp = *(struct avdp_t *)data;
 416     c->avdp_valid = 1;
 417     break;
 418   case PVDCache:
 419     c->pvd = *(struct pvd_t *)data;
 420     c->pvd_valid = 1;
 421     break;
 422   case PartitionCache:
 423     c->partition = *(struct Partition *)data;
 424     c->partition_valid = 1;
 425     break;
 426   case RootICBCache:
 427     c->rooticb = *(struct AD *)data;
 428     c->rooticb_valid = 1;
 429     break;
 430   case LBUDFCache:
 431     for(n = 0; n < c->lb_num; n++) {
 432       if(c->lbs[n].lb == nr) {
 433         /* replace with new data */
 434         c->lbs[n].data = *(uint8_t **)data;
 435         c->lbs[n].lb = nr;
 436         return 1;
 437       }
 438     }
 439     c->lb_num++;
 440     c->lbs = realloc(c->lbs, c->lb_num * sizeof(struct lbudf));
 441     /*
 442       fprintf(stderr, "realloc lb: %d * %d = %d\n",
 443       c->lb_num, sizeof(struct lbudf),
 444       c->lb_num * sizeof(struct lbudf));
 445     */
 446     if(c->lbs == NULL) {
 447       c->lb_num = 0;
 448       return 0;
 449     }
 450     c->lbs[n].data = *(uint8_t **)data;
 451     c->lbs[n].lb = nr;
 452     break;
 453   case MapCache:
 454     for(n = 0; n < c->map_num; n++) {
 455       if(c->maps[n].lbn == nr) {
 456         /* replace with new data */
 457         c->maps[n] = *(struct icbmap *)data;
 458         c->maps[n].lbn = nr;
 459         return 1;
 460       }
 461     }
 462     c->map_num++;
 463     c->maps = realloc(c->maps, c->map_num * sizeof(struct icbmap));
 464     /*
 465       fprintf(stderr, "realloc maps: %d * %d = %d\n",
 466       c->map_num, sizeof(struct icbmap),
 467       c->map_num * sizeof(struct icbmap));
 468     */
 469     if(c->maps == NULL) {
 470       c->map_num = 0;
 471       return 0;
 472     }
 473     c->maps[n] = *(struct icbmap *)data;
 474     c->maps[n].lbn = nr;
 475     break;
 476   default:
 477     return 0;
 478   }
 479
 480   return 1;
 481 }
 482
 483
 484 /* For direct data access, LSB first */
 485 #define GETN1(p) ((uint8_t)data[p])
 486 #define GETN2(p) ((uint16_t)data[p] | ((uint16_t)data[(p) + 1] << 8))
 487 #define GETN3(p) ((uint32_t)data[p] | ((uint32_t)data[(p) + 1] << 8)    \
 488                   | ((uint32_t)data[(p) + 2] << 16))
 489 #define GETN4(p) ((uint32_t)data[p]                     \
 490                   | ((uint32_t)data[(p) + 1] << 8)      \
 491                   | ((uint32_t)data[(p) + 2] << 16)     \
 492                   | ((uint32_t)data[(p) + 3] << 24))
 493 /* This is wrong with regard to endianess */
 494 #define GETN(p, n, target) memcpy(target, &data[p], n)
 495
 496 static int Unicodedecode( uint8_t *data, int len, char *target )
 497 {
 498   int p = 1, i = 0;
 499
 500   if( ( data[ 0 ] == 8 ) || ( data[ 0 ] == 16 ) ) do {
 501     if( data[ 0 ] == 16 ) p++;  /* Ignore MSB of unicode16 */
 502     if( p < len ) {
 503       target[ i++ ] = data[ p++ ];
 504     }
 505   } while( p < len );
 506
 507   target[ i ] = '\0';
 508   return 0;
 509 }
 510
 511 static int UDFDescriptor( uint8_t *data, uint16_t *TagID )
 512 {
 513   *TagID = GETN2(0);
 514   // TODO: check CRC 'n stuff
 515   return 0;
 516 }
 517
 518 static int UDFExtentAD( uint8_t *data, uint32_t *Length, uint32_t *Location )
 519 {
 520   *Length   = GETN4(0);
 521   *Location = GETN4(4);
 522   return 0;
 523 }
 524
 525 static int UDFShortAD( uint8_t *data, struct AD *ad,
 526                        struct Partition *partition )
 527 {
 528   ad->Length = GETN4(0);
 529   ad->Flags = ad->Length >> 30;
 530   ad->Length &= 0x3FFFFFFF;
 531   ad->Location = GETN4(4);
 532   ad->Partition = partition->Number; // use number of current partition
 533   return 0;
 534 }
 535
 536 static int UDFLongAD( uint8_t *data, struct AD *ad )
 537 {
 538   ad->Length = GETN4(0);
 539   ad->Flags = ad->Length >> 30;
 540   ad->Length &= 0x3FFFFFFF;
 541   ad->Location = GETN4(4);
 542   ad->Partition = GETN2(8);
 543   //GETN(10, 6, Use);
 544   return 0;
 545 }
 546
 547 static int UDFExtAD( uint8_t *data, struct AD *ad )
 548 {
 549   ad->Length = GETN4(0);
 550   ad->Flags = ad->Length >> 30;
 551   ad->Length &= 0x3FFFFFFF;
 552   ad->Location = GETN4(12);
 553   ad->Partition = GETN2(16);
 554   //GETN(10, 6, Use);
 555   return 0;
 556 }
 557
 558 static int UDFICB( uint8_t *data, uint8_t *FileType, uint16_t *Flags )
 559 {
 560   *FileType = GETN1(11);
 561   *Flags = GETN2(18);
 562   return 0;
 563 }
 564
 565
 566 static int UDFPartition( uint8_t *data, uint16_t *Flags, uint16_t *Number,
 567                          char *Contents, uint32_t *Start, uint32_t *Length )
 568 {
 569   *Flags = GETN2(20);
 570   *Number = GETN2(22);
 571   GETN(24, 32, Contents);
 572   *Start = GETN4(188);
 573   *Length = GETN4(192);
 574   return 0;
 575 }
 576
 577 /**
 578  * Reads the volume descriptor and checks the parameters.  Returns 0 on OK, 1
 579  * on error.
 580  */
 581 static int UDFLogVolume( uint8_t *data, char *VolumeDescriptor )
 582 {
 583   uint32_t lbsize, MT_L, N_PM;
 584   Unicodedecode(&data[84], 128, VolumeDescriptor);
 585   lbsize = GETN4(212);  // should be 2048
 586   MT_L = GETN4(264);    // should be 6
 587   N_PM = GETN4(268);    // should be 1
 588   if (lbsize != DVD_VIDEO_LB_LEN) return 1;
 589   return 0;
 590 }
 591
 592 static int UDFFileEntry( uint8_t *data, uint8_t *FileType,
 593                          struct Partition *partition, struct AD *ad )
 594 {
 595   uint16_t flags;
 596   uint32_t L_EA, L_AD;
 597   unsigned int p;
 598
 599   UDFICB( &data[ 16 ], FileType, &flags );
 600
 601   /* Init ad for an empty file (i.e. there isn't a AD, L_AD == 0 ) */
 602   ad->Length = GETN4( 60 ); // Really 8 bytes a 56
 603   ad->Flags = 0;
 604   ad->Location = 0; // what should we put here?
 605   ad->Partition = partition->Number; // use number of current partition
 606
 607   L_EA = GETN4( 168 );
 608   L_AD = GETN4( 172 );
 609   p = 176 + L_EA;
 610   while( p < 176 + L_EA + L_AD ) {
 611     switch( flags & 0x0007 ) {
 612     case 0: UDFShortAD( &data[ p ], ad, partition ); p += 8;  break;
 613     case 1: UDFLongAD( &data[ p ], ad );  p += 16; break;
 614     case 2: UDFExtAD( &data[ p ], ad );   p += 20; break;
 615     case 3:
 616       switch( L_AD ) {
 617       case 8:  UDFShortAD( &data[ p ], ad, partition ); break;
 618       case 16: UDFLongAD( &data[ p ], ad );  break;
 619       case 20: UDFExtAD( &data[ p ], ad );   break;
 620       }
 621       p += L_AD;
 622       break;
 623     default:
 624       p += L_AD; break;
 625     }
 626   }
 627   return 0;
 628 }
 629
 630 static int UDFFileIdentifier( uint8_t *data, uint8_t *FileCharacteristics,
 631                               char *FileName, struct AD *FileICB )
 632 {
 633   uint8_t L_FI;
 634   uint16_t L_IU;
 635
 636   *FileCharacteristics = GETN1(18);
 637   L_FI = GETN1(19);
 638   UDFLongAD(&data[20], FileICB);
 639   L_IU = GETN2(36);
 640   if (L_FI) Unicodedecode(&data[38 + L_IU], L_FI, FileName);
 641   else FileName[0] = '\0';
 642   return 4 * ((38 + L_FI + L_IU + 3) / 4);
 643 }
 644
 645 /**
 646  * Maps ICB to FileAD
 647  * ICB: Location of ICB of directory to scan
 648  * FileType: Type of the file
 649  * File: Location of file the ICB is pointing to
 650  * return 1 on success, 0 on error;
 651  */
 652 static int UDFMapICB( dvd_reader_t *device, struct AD ICB, uint8_t *FileType,
 653                       struct Partition *partition, struct AD *File )
 654 {
 655   uint8_t *LogBlock;
 656   uint32_t lbnum;
 657   uint16_t TagID;
 658   struct icbmap tmpmap;
 659
 660   lbnum = partition->Start + ICB.Location;
 661   tmpmap.lbn = lbnum;
 662   if(GetUDFCache(device, MapCache, lbnum, &tmpmap)) {
 663     *FileType = tmpmap.filetype;
 664     *File = tmpmap.file;
 665     return 1;
 666   }
 667
 668   LogBlock = dvdalign_lbmalloc(device, 1);
 669   if(!LogBlock) {
 670     return 0;
 671   }
 672
 673   do {
 674     if( DVDReadLBUDF( device, lbnum++, 1, LogBlock, 0 ) <= 0 ) {
 675       TagID = 0;
 676     } else {
 677       UDFDescriptor( LogBlock, &TagID );
 678     }
 679
 680     if( TagID == 261 ) {
 681       UDFFileEntry( LogBlock, FileType, partition, File );
 682       tmpmap.file = *File;
 683       tmpmap.filetype = *FileType;
 684       SetUDFCache(device, MapCache, tmpmap.lbn, &tmpmap);
 685       dvdalign_lbfree(device, LogBlock);
 686       return 1;
 687     };
 688   } while( ( lbnum <= partition->Start + ICB.Location + ( ICB.Length - 1 )
 689              / DVD_VIDEO_LB_LEN ) && ( TagID != 261 ) );
 690
 691   dvdalign_lbfree(device, LogBlock);
 692   return 0;
 693 }
 694
 695 /**
 696  * Dir: Location of directory to scan
 697  * FileName: Name of file to look for
 698  * FileICB: Location of ICB of the found file
 699  * return 1 on success, 0 on error;
 700  */
 701 static int UDFScanDir( dvd_reader_t *device, struct AD Dir, char *FileName,
 702                        struct Partition *partition, struct AD *FileICB,
 703                        int cache_file_info)
 704 {
 705   char filename[ MAX_UDF_FILE_NAME_LEN ];
 706   uint8_t *directory;
 707   uint32_t lbnum;
 708   uint16_t TagID;
 709   uint8_t filechar;
 710   unsigned int p;
 711   uint8_t *cached_dir = NULL;
 712   uint32_t dir_lba;
 713   struct AD tmpICB;
 714   int found = 0;
 715   int in_cache = 0;
 716
 717   /* Scan dir for ICB of file */
 718   lbnum = partition->Start + Dir.Location;
 719
 720   if(DVDUDFCacheLevel(device, -1) > 0) {
 721     /* caching */
 722
 723     if(!GetUDFCache(device, LBUDFCache, lbnum, &cached_dir)) {
 724       dir_lba = (Dir.Length + DVD_VIDEO_LB_LEN) / DVD_VIDEO_LB_LEN;
 725       if((cached_dir = dvdalign_lbmalloc(device, dir_lba)) == NULL) {
 726         return 0;
 727       }
 728       if( DVDReadLBUDF( device, lbnum, dir_lba, cached_dir, 0) <= 0 ) {
 729         dvdalign_lbfree(device, cached_dir);
 730         cached_dir = NULL;
 731       }
 732       SetUDFCache(device, LBUDFCache, lbnum, &cached_dir);
 733     } else {
 734       in_cache = 1;
 735     }
 736
 737     if(cached_dir == NULL) {
 738       return 0;
 739     }
 740
 741     p = 0;
 742
 743     while( p < Dir.Length ) {
 744       UDFDescriptor( &cached_dir[ p ], &TagID );
 745       if( TagID == 257 ) {
 746         p += UDFFileIdentifier( &cached_dir[ p ], &filechar,
 747                                 filename, &tmpICB );
 748         if(cache_file_info && !in_cache) {
 749           uint8_t tmpFiletype;
 750           struct AD tmpFile;
 751
 752           if( !strcasecmp( FileName, filename ) ) {
 753             *FileICB = tmpICB;
 754             found = 1;
 755
 756           }
 757           UDFMapICB(device, tmpICB, &tmpFiletype,
 758                     partition, &tmpFile);
 759         } else {
 760           if( !strcasecmp( FileName, filename ) ) {
 761             *FileICB = tmpICB;
 762             return 1;
 763           }
 764         }
 765       } else {
 766         if(cache_file_info && (!in_cache) && found) {
 767           return 1;
 768         }
 769         return 0;
 770       }
 771     }
 772     if(cache_file_info && (!in_cache) && found) {
 773       return 1;
 774     }
 775     return 0;
 776   }
 777
 778   directory = dvdalign_lbmalloc(device, 2);
 779   if(!directory) {
 780     return 0;
 781   }
 782   if( DVDReadLBUDF( device, lbnum, 2, directory, 0 ) <= 0 ) {
 783     dvdalign_lbfree(device, directory);
 784     return 0;
 785   }
 786
 787   p = 0;
 788   while( p < Dir.Length ) {
 789     if( p > DVD_VIDEO_LB_LEN ) {
 790       ++lbnum;
 791       p -= DVD_VIDEO_LB_LEN;
 792       Dir.Length -= DVD_VIDEO_LB_LEN;
 793       if( DVDReadLBUDF( device, lbnum, 2, directory, 0 ) <= 0 ) {
 794         dvdalign_lbfree(device, directory);
 795         return 0;
 796       }
 797     }
 798     UDFDescriptor( &directory[ p ], &TagID );
 799     if( TagID == 257 ) {
 800       p += UDFFileIdentifier( &directory[ p ], &filechar,
 801                               filename, FileICB );
 802       if( !strcasecmp( FileName, filename ) ) {
 803         dvdalign_lbfree(device, directory);
 804         return 1;
 805       }
 806     } else {
 807       dvdalign_lbfree(device, directory);
 808       return 0;
 809     }
 810   }
 811
 812   dvdalign_lbfree(device, directory);
 813   return 0;
 814 }
 815
 816
 817 static int UDFGetAVDP( dvd_reader_t *device,
 818                        struct avdp_t *avdp)
 819 {
 820   uint8_t *Anchor;
 821   uint32_t lbnum, MVDS_location, MVDS_length;
 822   uint16_t TagID;
 823   uint32_t lastsector;
 824   int terminate;
 825   struct avdp_t;
 826
 827   if(GetUDFCache(device, AVDPCache, 0, avdp)) {
 828     return 1;
 829   }
 830
 831   /* Find Anchor */
 832   lastsector = 0;
 833   lbnum = 256;   /* Try #1, prime anchor */
 834   terminate = 0;
 835
 836   Anchor = dvdalign_lbmalloc(device, 1);
 837   if(!Anchor) {
 838     return 0;
 839   }
 840   for(;;) {
 841     if( DVDReadLBUDF( device, lbnum, 1, Anchor, 0 ) > 0 ) {
 842       UDFDescriptor( Anchor, &TagID );
 843     } else {
 844       TagID = 0;
 845     }
 846     if (TagID != 2) {
 847       /* Not an anchor */
 848       if( terminate ) {
 849         dvdalign_lbfree(device, Anchor);
 850         errno = EMEDIUMTYPE;
 851         return 0; /* Final try failed */
 852       }
 853
 854       if( lastsector ) {
 855         /* We already found the last sector.  Try #3, alternative
 856          * backup anchor.  If that fails, don't try again.
 857          */
 858         lbnum = lastsector;
 859         terminate = 1;
 860       } else {
 861         /* TODO: Find last sector of the disc (this is optional). */
 862         if( lastsector ) {
 863           /* Try #2, backup anchor */
 864           lbnum = lastsector - 256;
 865         } else {
 866           /* Unable to find last sector */
 867           dvdalign_lbfree(device, Anchor);
 868           errno = EMEDIUMTYPE;
 869           return 0;
 870         }
 871       }
 872     } else {
 873       /* It's an anchor! We can leave */
 874       break;
 875     }
 876   }
 877   /* Main volume descriptor */
 878   UDFExtentAD( &Anchor[ 16 ], &MVDS_length, &MVDS_location );
 879   avdp->mvds.location = MVDS_location;
 880   avdp->mvds.length = MVDS_length;
 881
 882   /* Backup volume descriptor */
 883   UDFExtentAD( &Anchor[ 24 ], &MVDS_length, &MVDS_location );
 884   avdp->rvds.location = MVDS_location;
 885   avdp->rvds.length = MVDS_length;
 886
 887   SetUDFCache(device, AVDPCache, 0, avdp);
 888
 889   dvdalign_lbfree(device, Anchor);
 890   return 1;
 891 }
 892
 893 /**
 894  * Looks for partition on the disc.  Returns 1 if partition found, 0 on error.
 895  *   partnum: Number of the partition, starting at 0.
 896  *   part: structure to fill with the partition information
 897  */
 898 static int UDFFindPartition( dvd_reader_t *device, int partnum,
 899                              struct Partition *part )
 900 {
 901   uint8_t *LogBlock;
 902   uint32_t lbnum, MVDS_location, MVDS_length;
 903   uint16_t TagID;
 904   int i, volvalid;
 905   struct avdp_t avdp;
 906
 907
 908   if(!UDFGetAVDP(device, &avdp)) {
 909     return 0;
 910   }
 911
 912   LogBlock = dvdalign_lbmalloc(device, 1);
 913   if(!LogBlock) {
 914     return 0;
 915   }
 916   /* Main volume descriptor */
 917   MVDS_location = avdp.mvds.location;
 918   MVDS_length = avdp.mvds.length;
 919
 920   part->valid = 0;
 921   volvalid = 0;
 922   part->VolumeDesc[ 0 ] = '\0';
 923   i = 1;
 924   do {
 925     /* Find Volume Descriptor */
 926     lbnum = MVDS_location;
 927     do {
 928
 929       if( DVDReadLBUDF( device, lbnum++, 1, LogBlock, 0 ) <= 0 ) {
 930         TagID = 0;
 931       } else {
 932         UDFDescriptor( LogBlock, &TagID );
 933       }
 934
 935       if( ( TagID == 5 ) && ( !part->valid ) ) {
 936         /* Partition Descriptor */
 937         UDFPartition( LogBlock, &part->Flags, &part->Number,
 938                       part->Contents, &part->Start, &part->Length );
 939         part->valid = ( partnum == part->Number );
 940       } else if( ( TagID == 6 ) && ( !volvalid ) ) {
 941         /* Logical Volume Descriptor */
 942         if( UDFLogVolume( LogBlock, part->VolumeDesc ) ) {
 943           /* TODO: sector size wrong! */
 944         } else {
 945           volvalid = 1;
 946         }
 947       }
 948
 949     } while( ( lbnum <= MVDS_location + ( MVDS_length - 1 )
 950                / DVD_VIDEO_LB_LEN ) && ( TagID != 8 )
 951              && ( ( !part->valid ) || ( !volvalid ) ) );
 952
 953     if( ( !part->valid) || ( !volvalid ) ) {
 954       /* Backup volume descriptor */
 955       MVDS_location = avdp.mvds.location;
 956       MVDS_length = avdp.mvds.length;
 957     }
 958   } while( i-- && ( ( !part->valid ) || ( !volvalid ) ) );
 959
 960   dvdalign_lbfree(device, LogBlock);
 961   /* We only care for the partition, not the volume */
 962   return part->valid;
 963 }
 964
 965 uint32_t UDFFindFile( dvd_reader_t *device, char *filename,
 966                       uint32_t *filesize )
 967 {
 968   uint8_t *LogBlock;
 969   uint32_t lbnum;
 970   uint16_t TagID;
 971   struct Partition partition;
 972   struct AD RootICB, File, ICB;
 973   char tokenline[ MAX_UDF_FILE_NAME_LEN ];
 974   char *token;
 975   uint8_t filetype;
 976
 977   if(filesize) {
 978     *filesize = 0;
 979   }
 980   tokenline[0] = '\0';
 981   strcat( tokenline, filename );
 982
 983
 984   if(!(GetUDFCache(device, PartitionCache, 0, &partition) &&
 985        GetUDFCache(device, RootICBCache, 0, &RootICB))) {
 986     /* Find partition, 0 is the standard location for DVD Video.*/
 987     if( !UDFFindPartition( device, 0, &partition ) ) {
 988       return 0;
 989     }
 990     SetUDFCache(device, PartitionCache, 0, &partition);
 991
 992     LogBlock = dvdalign_lbmalloc(device, 1);
 993     if(!LogBlock) {
 994       return 0;
 995     }
 996     /* Find root dir ICB */
 997     lbnum = partition.Start;
 998     do {
 999       if( DVDReadLBUDF( device, lbnum++, 1, LogBlock, 0 ) <= 0 ) {
1000         TagID = 0;
1001       } else {
1002         UDFDescriptor( LogBlock, &TagID );
1003       }
1004
1005       /* File Set Descriptor */
1006       if( TagID == 256 ) {  // File Set Descriptor
1007         UDFLongAD( &LogBlock[ 400 ], &RootICB );
1008       }
1009     } while( ( lbnum < partition.Start + partition.Length )
1010              && ( TagID != 8 ) && ( TagID != 256 ) );
1011
1012     dvdalign_lbfree(device, LogBlock);
1013
1014     /* Sanity checks. */
1015     if( TagID != 256 ) {
1016       return 0;
1017     }
1018     if( RootICB.Partition != 0 ) {
1019       return 0;
1020     }
1021     SetUDFCache(device, RootICBCache, 0, &RootICB);
1022   }
1023
1024   /* Find root dir */
1025   if( !UDFMapICB( device, RootICB, &filetype, &partition, &File ) ) {
1026     return 0;
1027   }
1028   if( filetype != 4 ) {
1029     return 0;  /* Root dir should be dir */
1030   }
1031   {
1032     int cache_file_info = 0;
1033     /* Tokenize filepath */
1034     token = strtok(tokenline, "/");
1035
1036     while( token != NULL ) {
1037
1038       if( !UDFScanDir( device, File, token, &partition, &ICB,
1039                        cache_file_info)) {
1040         return 0;
1041       }
1042       if( !UDFMapICB( device, ICB, &filetype, &partition, &File ) ) {
1043         return 0;
1044       }
1045       if(!strcmp(token, "VIDEO_TS")) {
1046         cache_file_info = 1;
1047       }
1048       token = strtok( NULL, "/" );
1049     }
1050   }
1051
1052   /* Sanity check. */
1053   if( File.Partition != 0 ) {
1054     return 0;
1055   }
1056
1057   if(filesize) {
1058     *filesize = File.Length;
1059   }
1060   /* Hack to not return partition.Start for empty files. */
1061   if( !File.Location ) {
1062     return 0;
1063   } else {
1064     return partition.Start + File.Location;
1065   }
1066 }
1067
1068
1069
1070 /**
1071  * Gets a Descriptor .
1072  * Returns 1 if descriptor found, 0 on error.
1073  * id, tagid of descriptor
1074  * bufsize, size of BlockBuf (must be >= DVD_VIDEO_LB_LEN)
1075  * and aligned for raw/O_DIRECT read.
1076  */
1077 static int UDFGetDescriptor( dvd_reader_t *device, int id,
1078                              uint8_t *descriptor, int bufsize)
1079 {
1080   uint32_t lbnum, MVDS_location, MVDS_length;
1081   struct avdp_t avdp;
1082   uint16_t TagID;
1083   uint32_t lastsector;
1084   int i, terminate;
1085   int desc_found = 0;
1086   /* Find Anchor */
1087   lastsector = 0;
1088   lbnum = 256;   /* Try #1, prime anchor */
1089   terminate = 0;
1090   if(bufsize < DVD_VIDEO_LB_LEN) {
1091     return 0;
1092   }
1093
1094   if(!UDFGetAVDP(device, &avdp)) {
1095     return 0;
1096   }
1097
1098   /* Main volume descriptor */
1099   MVDS_location = avdp.mvds.location;
1100   MVDS_length = avdp.mvds.length;
1101
1102   i = 1;
1103   do {
1104     /* Find  Descriptor */
1105     lbnum = MVDS_location;
1106     do {
1107
1108       if( DVDReadLBUDF( device, lbnum++, 1, descriptor, 0 ) <= 0 ) {
1109         TagID = 0;
1110       } else {
1111         UDFDescriptor( descriptor, &TagID );
1112       }
1113
1114       if( (TagID == id) && ( !desc_found ) ) {
1115         /* Descriptor */
1116         desc_found = 1;
1117       }
1118     } while( ( lbnum <= MVDS_location + ( MVDS_length - 1 )
1119                / DVD_VIDEO_LB_LEN ) && ( TagID != 8 )
1120              && ( !desc_found) );
1121
1122     if( !desc_found ) {
1123       /* Backup volume descriptor */
1124       MVDS_location = avdp.rvds.location;
1125       MVDS_length = avdp.rvds.length;
1126     }
1127   } while( i-- && ( !desc_found )  );
1128
1129
1130   return desc_found;
1131 }
1132
1133
1134 static int UDFGetPVD(dvd_reader_t *device, struct pvd_t *pvd)
1135 {
1136   uint8_t *pvd_buf;
1137
1138   if(GetUDFCache(device, PVDCache, 0, pvd)) {
1139     return 1;
1140   }
1141
1142   pvd_buf = dvdalign_lbmalloc(device, 1);
1143   if(!pvd_buf) {
1144     return 0;
1145   }
1146   if(!UDFGetDescriptor( device, 1, pvd_buf, 1*DVD_VIDEO_LB_LEN)) {
1147     dvdalign_lbfree(device, pvd_buf);
1148     return 0;
1149   }
1150
1151   memcpy(pvd->VolumeIdentifier, &pvd_buf[24], 32);
1152   memcpy(pvd->VolumeSetIdentifier, &pvd_buf[72], 128);
1153   SetUDFCache(device, PVDCache, 0, pvd);
1154
1155   dvdalign_lbfree(device, pvd_buf);
1156
1157   return 1;
1158 }
1159
1160 /**
1161  * Gets the Volume Identifier string, in 8bit unicode (latin-1)
1162  * volid, place to put the string
1163  * volid_size, size of the buffer volid points to
1164  * returns the size of buffer needed for all data
1165  */
1166 int UDFGetVolumeIdentifier(dvd_reader_t *device, char *volid,
1167                            unsigned int volid_size)
1168 {
1169   struct pvd_t pvd;
1170   unsigned int volid_len;
1171
1172   /* get primary volume descriptor */
1173   if(!UDFGetPVD(device, &pvd)) {
1174     return 0;
1175   }
1176
1177   volid_len = pvd.VolumeIdentifier[31];
1178   if(volid_len > 31) {
1179     /* this field is only 32 bytes something is wrong */
1180     volid_len = 31;
1181   }
1182   if(volid_size > volid_len) {
1183     volid_size = volid_len;
1184   }
1185   Unicodedecode(pvd.VolumeIdentifier, volid_size, volid);
1186
1187   return volid_len;
1188 }
1189
1190 /**
1191  * Gets the Volume Set Identifier, as a 128-byte dstring (not decoded)
1192  * WARNING This is not a null terminated string
1193  * volsetid, place to put the data
1194  * volsetid_size, size of the buffer volsetid points to
1195  * the buffer should be >=128 bytes to store the whole volumesetidentifier
1196  * returns the size of the available volsetid information (128)
1197  * or 0 on error
1198  */
1199 int UDFGetVolumeSetIdentifier(dvd_reader_t *device, uint8_t *volsetid,
1200                               unsigned int volsetid_size)
1201 {
1202   struct pvd_t pvd;
1203
1204   /* get primary volume descriptor */
1205   if(!UDFGetPVD(device, &pvd)) {
1206     return 0;
1207   }
1208
1209
1210   if(volsetid_size > 128) {
1211     volsetid_size = 128;
1212   }
1213
1214   memcpy(volsetid, pvd.VolumeSetIdentifier, volsetid_size);
1215
1216   return 128;
1217 }