vo_tag: fix RGB with alpha output on little-endian
[mplayer/glamo.git] / libdvdcss / libdvdcss.c
blobd13d0c9a4dbc1c15dba6c7ac9b04af09195ff7a2
1 /* libdvdcss.c: DVD reading library.
3 * Authors: Stéphane Borel <stef@via.ecp.fr>
4 * Sam Hocevar <sam@zoy.org>
5 * Håkan Hjort <d95hjort@dtek.chalmers.se>
7 * Copyright (C) 1998-2008 VideoLAN
8 * $Id$
10 * This library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License along
21 * with this library; if not, write to the Free Software Foundation, Inc.,
22 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
25 /**
26 * \mainpage libdvdcss developer documentation
28 * \section intro Introduction
30 * \e libdvdcss is a simple library designed for accessing DVDs like a block
31 * device without having to bother about the decryption. The important features
32 * are:
33 * \li portability: currently supported platforms are GNU/Linux, FreeBSD,
34 * NetBSD, OpenBSD, BSD/OS, BeOS, Windows 95/98, Windows NT/2000, MacOS X,
35 * Solaris, HP-UX and OS/2.
36 * \li adaptability: unlike most similar projects, libdvdcss doesn't require
37 * the region of your drive to be set and will try its best to read from
38 * the disc even in the case of a region mismatch.
39 * \li simplicity: a DVD player can be built around the \e libdvdcss API using
40 * no more than 4 or 5 library calls.
42 * \e libdvdcss is free software, released under the General Public License.
43 * This ensures that \e libdvdcss remains free and used only with free
44 * software.
46 * \section api The libdvdcss API
48 * The complete \e libdvdcss programming interface is documented in the
49 * dvdcss.h file.
51 * \section env Environment variables
53 * Some environment variables can be used to change the behaviour of
54 * \e libdvdcss without having to modify the program which uses it. These
55 * variables are:
57 * \li \b DVDCSS_VERBOSE: sets the verbosity level.
58 * - \c 0 outputs no messages at all.
59 * - \c 1 outputs error messages to stderr.
60 * - \c 2 outputs error messages and debug messages to stderr.
62 * \li \b DVDCSS_METHOD: sets the authentication and decryption method
63 * that \e libdvdcss will use to read scrambled discs. Can be one
64 * of \c title, \c key or \c disc.
65 * - \c key is the default method. \e libdvdcss will use a set of
66 * calculated player keys to try and get the disc key. This can fail
67 * if the drive does not recognize any of the player keys.
68 * - \c disc is a fallback method when \c key has failed. Instead of
69 * using player keys, \e libdvdcss will crack the disc key using
70 * a brute force algorithm. This process is CPU intensive and requires
71 * 64 MB of memory to store temporary data.
72 * - \c title is the fallback when all other methods have failed. It does
73 * not rely on a key exchange with the DVD drive, but rather uses a
74 * crypto attack to guess the title key. On rare cases this may fail
75 * because there is not enough encrypted data on the disc to perform
76 * a statistical attack, but in the other hand it is the only way to
77 * decrypt a DVD stored on a hard disc, or a DVD with the wrong region
78 * on an RPC2 drive.
80 * \li \b DVDCSS_RAW_DEVICE: specify the raw device to use. Exact usage will
81 * depend on your operating system, the Linux utility to set up raw devices
82 * is \c raw(8) for instance. Please note that on most operating systems,
83 * using a raw device requires highly aligned buffers: Linux requires a
84 * 2048 bytes alignment (which is the size of a DVD sector).
86 * \li \b DVDCSS_CACHE: specify a directory in which to store title key
87 * values. This will speed up descrambling of DVDs which are in the
88 * cache. The DVDCSS_CACHE directory is created if it does not exist,
89 * and a subdirectory is created named after the DVD's title or
90 * manufacturing date. If DVDCSS_CACHE is not set or is empty, \e libdvdcss
91 * will use the default value which is "${HOME}/.dvdcss/" under Unix and
92 * "C:\Documents and Settings\$USER\Application Data\dvdcss\" under Win32.
93 * The special value "off" disables caching.
97 * Preamble
99 #include "config.h"
101 #include <stdio.h>
102 #include <stdlib.h>
103 #include <string.h>
104 #include <sys/types.h>
105 #include <sys/stat.h>
106 #ifdef HAVE_SYS_PARAM_H
107 # include <sys/param.h>
108 #endif
109 #ifdef HAVE_PWD_H
110 # include <pwd.h>
111 #endif
112 #include <fcntl.h>
113 #include <errno.h>
115 #ifdef HAVE_UNISTD_H
116 # include <unistd.h>
117 #endif
119 #ifdef HAVE_LIMITS_H
120 # include <limits.h>
121 #endif
123 #ifdef HAVE_DIRECT_H
124 # include <direct.h>
125 #endif
127 #include "dvdcss/dvdcss.h"
129 #include "common.h"
130 #include "css.h"
131 #include "libdvdcss.h"
132 #include "ioctl.h"
133 #include "device.h"
136 * \brief Symbol for version checks.
138 * The name of this symbol contains the library major number, which makes it
139 * easy to check which \e libdvdcss development headers are installed on the
140 * system with tools such as autoconf.
142 * The variable itself contains the exact version number of the library,
143 * which can be useful for specific feature needs.
145 char * dvdcss_interface_2 = VERSION;
148 * \brief Open a DVD device or directory and return a dvdcss instance.
150 * \param psz_target a string containing the target name, for instance
151 * "/dev/hdc" or "E:".
152 * \return a handle to a dvdcss instance or NULL on error.
154 * Initialize the \e libdvdcss library and open the requested DVD device or
155 * directory. \e libdvdcss checks whether ioctls can be performed on the disc,
156 * and when possible, the disc key is retrieved.
158 * dvdcss_open() returns a handle to be used for all subsequent \e libdvdcss
159 * calls. If an error occurred, NULL is returned.
161 LIBDVDCSS_EXPORT dvdcss_t dvdcss_open ( char *psz_target )
163 char psz_buffer[PATH_MAX];
164 int i_ret;
166 char *psz_method = getenv( "DVDCSS_METHOD" );
167 char *psz_verbose = getenv( "DVDCSS_VERBOSE" );
168 char *psz_cache = getenv( "DVDCSS_CACHE" );
169 #if !defined(WIN32) && !defined(SYS_OS2)
170 char *psz_raw_device = getenv( "DVDCSS_RAW_DEVICE" );
171 #endif
173 dvdcss_t dvdcss;
176 * Allocate the library structure
178 dvdcss = malloc( sizeof( struct dvdcss_s ) );
179 if( dvdcss == NULL )
181 return NULL;
185 * Initialize structure with default values
187 #if !defined(WIN32) && !defined(SYS_OS2)
188 dvdcss->i_raw_fd = -1;
189 #endif
190 dvdcss->p_titles = NULL;
191 dvdcss->psz_device = (char *)strdup( psz_target );
192 dvdcss->psz_error = "no error";
193 dvdcss->i_method = DVDCSS_METHOD_KEY;
194 dvdcss->psz_cachefile[0] = '\0';
195 dvdcss->b_debug = 0;
196 dvdcss->b_errors = 0;
199 * Find verbosity from DVDCSS_VERBOSE environment variable
201 if( psz_verbose != NULL )
203 int i = atoi( psz_verbose );
205 if( i >= 2 ) dvdcss->b_debug = i;
206 if( i >= 1 ) dvdcss->b_errors = 1;
210 * Find method from DVDCSS_METHOD environment variable
212 if( psz_method != NULL )
214 if( !strncmp( psz_method, "key", 4 ) )
216 dvdcss->i_method = DVDCSS_METHOD_KEY;
218 else if( !strncmp( psz_method, "disc", 5 ) )
220 dvdcss->i_method = DVDCSS_METHOD_DISC;
222 else if( !strncmp( psz_method, "title", 5 ) )
224 dvdcss->i_method = DVDCSS_METHOD_TITLE;
226 else
228 print_error( dvdcss, "unknown decrypt method, please choose "
229 "from 'title', 'key' or 'disc'" );
230 free( dvdcss->psz_device );
231 free( dvdcss );
232 return NULL;
237 * If DVDCSS_CACHE was not set, try to guess a default value
239 if( psz_cache == NULL || psz_cache[0] == '\0' )
241 #ifdef HAVE_DIRECT_H
242 typedef HRESULT( WINAPI *SHGETFOLDERPATH )
243 ( HWND, int, HANDLE, DWORD, LPTSTR );
245 # define CSIDL_FLAG_CREATE 0x8000
246 # define CSIDL_APPDATA 0x1A
247 # define SHGFP_TYPE_CURRENT 0
249 char psz_home[MAX_PATH];
250 HINSTANCE p_dll;
251 SHGETFOLDERPATH p_getpath;
253 *psz_home = '\0';
255 /* Load the shfolder dll to retrieve SHGetFolderPath */
256 p_dll = LoadLibrary( "shfolder.dll" );
257 if( p_dll )
259 p_getpath = (void*)GetProcAddress( p_dll, "SHGetFolderPathA" );
260 if( p_getpath )
262 /* Get the "Application Data" folder for the current user */
263 if( p_getpath( NULL, CSIDL_APPDATA | CSIDL_FLAG_CREATE,
264 NULL, SHGFP_TYPE_CURRENT, psz_home ) == S_OK )
266 FreeLibrary( p_dll );
268 else
270 *psz_home = '\0';
273 FreeLibrary( p_dll );
276 /* Cache our keys in
277 * C:\Documents and Settings\$USER\Application Data\dvdcss\ */
278 if( *psz_home )
280 snprintf( psz_buffer, PATH_MAX, "%s/dvdcss", psz_home );
281 psz_buffer[PATH_MAX-1] = '\0';
282 psz_cache = psz_buffer;
284 #else
285 char *psz_home = NULL;
286 # ifdef HAVE_PWD_H
287 struct passwd *p_pwd;
289 /* Try looking in password file for home dir. */
290 p_pwd = getpwuid(getuid());
291 if( p_pwd )
293 psz_home = p_pwd->pw_dir;
295 # endif
297 if( psz_home == NULL )
299 psz_home = getenv( "HOME" );
301 if( psz_home == NULL )
303 psz_home = getenv( "USERPROFILE" );
306 /* Cache our keys in ${HOME}/.dvdcss/ */
307 if( psz_home )
309 int home_pos = 0;
311 #ifdef SYS_OS2
312 if( *psz_home == '/' || *psz_home == '\\')
314 char *psz_unixroot = getenv("UNIXROOT");
316 if( psz_unixroot &&
317 psz_unixroot[0] &&
318 psz_unixroot[1] == ':' &&
319 psz_unixroot[2] == '\0')
321 strcpy( psz_buffer, psz_unixroot );
322 home_pos = 2;
325 #endif
326 snprintf( psz_buffer + home_pos, PATH_MAX - home_pos,
327 "%s/.dvdcss", psz_home );
328 psz_buffer[PATH_MAX-1] = '\0';
329 psz_cache = psz_buffer;
331 #endif
335 * Find cache dir from the DVDCSS_CACHE environment variable
337 if( psz_cache != NULL )
339 if( psz_cache[0] == '\0' || !strcmp( psz_cache, "off" ) )
341 psz_cache = NULL;
343 /* Check that we can add the ID directory and the block filename */
344 else if( strlen( psz_cache ) + 1 + 32 + 1 + (KEY_SIZE * 2) + 10 + 1
345 > PATH_MAX )
347 print_error( dvdcss, "cache directory name is too long" );
348 psz_cache = NULL;
353 * Open device
355 _dvdcss_check( dvdcss );
356 i_ret = _dvdcss_open( dvdcss );
357 if( i_ret < 0 )
359 free( dvdcss->psz_device );
360 free( dvdcss );
361 return NULL;
364 dvdcss->b_scrambled = 1; /* Assume the worst */
365 dvdcss->b_ioctls = _dvdcss_use_ioctls( dvdcss );
367 if( dvdcss->b_ioctls )
369 i_ret = _dvdcss_test( dvdcss );
371 if( i_ret == -3 )
373 print_debug( dvdcss, "scrambled disc on a region-free RPC-II "
374 "drive: possible failure, but continuing "
375 "anyway" );
377 else if( i_ret < 0 )
379 /* Disable the CSS ioctls and hope that it works? */
380 print_debug( dvdcss,
381 "could not check whether the disc was scrambled" );
382 dvdcss->b_ioctls = 0;
384 else
386 print_debug( dvdcss, i_ret ? "disc is scrambled"
387 : "disc is unscrambled" );
388 dvdcss->b_scrambled = i_ret;
392 /* If disc is CSS protected and the ioctls work, authenticate the drive */
393 if( dvdcss->b_scrambled && dvdcss->b_ioctls )
395 i_ret = _dvdcss_disckey( dvdcss );
397 if( i_ret < 0 )
399 print_debug( dvdcss, "could not get disc key" );
402 else
404 memset( dvdcss->css.p_disc_key, 0, KEY_SIZE );
407 /* If the cache is enabled, write the cache directory tag */
408 if( psz_cache )
410 char *psz_tag = "Signature: 8a477f597d28d172789f06886806bc55\r\n"
411 "# This file is a cache directory tag created by libdvdcss.\r\n"
412 "# For information about cache directory tags, see:\r\n"
413 "# http://www.brynosaurus.com/cachedir/\r\n";
414 char psz_tagfile[PATH_MAX + 1 + 12 + 1];
415 int i_fd;
417 sprintf( psz_tagfile, "%s/CACHEDIR.TAG", psz_cache );
418 i_fd = open( psz_tagfile, O_RDWR|O_CREAT, 0644 );
419 if( i_fd >= 0 )
421 write( i_fd, psz_tag, strlen(psz_tag) );
422 close( i_fd );
426 /* If the cache is enabled, extract a unique disc ID */
427 if( psz_cache )
429 uint8_t p_sector[DVDCSS_BLOCK_SIZE];
430 char psz_key[1 + KEY_SIZE * 2 + 1];
431 char *psz_title;
432 uint8_t *psz_serial;
433 int i;
435 /* We read sector 0. If it starts with 0x000001ba (BE), we are
436 * reading a VOB file, and we should not cache anything. */
438 i_ret = dvdcss->pf_seek( dvdcss, 0 );
439 if( i_ret != 0 )
441 goto nocache;
444 i_ret = dvdcss->pf_read( dvdcss, p_sector, 1 );
445 if( i_ret != 1 )
447 goto nocache;
450 if( p_sector[0] == 0x00 && p_sector[1] == 0x00
451 && p_sector[2] == 0x01 && p_sector[3] == 0xba )
453 goto nocache;
456 /* The data we are looking for is at sector 16 (32768 bytes):
457 * - offset 40: disc title (32 uppercase chars)
458 * - offset 813: manufacturing date + serial no (16 digits) */
460 i_ret = dvdcss->pf_seek( dvdcss, 16 );
461 if( i_ret != 16 )
463 goto nocache;
466 i_ret = dvdcss->pf_read( dvdcss, p_sector, 1 );
467 if( i_ret != 1 )
469 goto nocache;
472 /* Get the disc title */
473 psz_title = (char *)p_sector + 40;
474 psz_title[32] = '\0';
476 for( i = 0 ; i < 32 ; i++ )
478 if( psz_title[i] <= ' ' )
480 psz_title[i] = '\0';
481 break;
483 else if( psz_title[i] == '/' || psz_title[i] == '\\' )
485 psz_title[i] = '-';
489 /* Get the date + serial */
490 psz_serial = p_sector + 813;
491 psz_serial[16] = '\0';
493 /* Check that all characters are digits, otherwise convert. */
494 for( i = 0 ; i < 16 ; i++ )
496 if( psz_serial[i] < '0' || psz_serial[i] > '9' )
498 char psz_tmp[16 + 1];
499 sprintf( psz_tmp,
500 "%.2x%.2x%.2x%.2x%.2x%.2x%.2x%.2x",
501 psz_serial[0], psz_serial[1], psz_serial[2],
502 psz_serial[3], psz_serial[4], psz_serial[5],
503 psz_serial[6], psz_serial[7] );
504 memcpy( psz_serial, psz_tmp, 16 );
505 break;
509 /* Get disk key, since some discs have got same title, manufacturing
510 * date and serial number, but different keys */
511 if( dvdcss->b_scrambled )
513 psz_key[0] = '-';
514 for( i = 0; i < KEY_SIZE; i++ )
516 sprintf( &psz_key[1+i*2], "%.2x", dvdcss->css.p_disc_key[i] );
518 psz_key[1 + KEY_SIZE * 2] = '\0';
520 else
522 psz_key[0] = 0;
525 /* We have a disc name or ID, we can create the cache dir */
526 i = sprintf( dvdcss->psz_cachefile, "%s", psz_cache );
527 #if !defined( WIN32 ) || defined( SYS_CYGWIN )
528 i_ret = mkdir( dvdcss->psz_cachefile, 0755 );
529 #else
530 i_ret = mkdir( dvdcss->psz_cachefile );
531 #endif
532 if( i_ret < 0 && errno != EEXIST )
534 print_error( dvdcss, "failed creating cache directory" );
535 dvdcss->psz_cachefile[0] = '\0';
536 goto nocache;
539 i += sprintf( dvdcss->psz_cachefile + i, "/%s-%s%s", psz_title,
540 psz_serial, psz_key );
541 #if !defined( WIN32 ) || defined( SYS_CYGWIN )
542 i_ret = mkdir( dvdcss->psz_cachefile, 0755 );
543 #else
544 i_ret = mkdir( dvdcss->psz_cachefile );
545 #endif
546 if( i_ret < 0 && errno != EEXIST )
548 print_error( dvdcss, "failed creating cache subdirectory" );
549 dvdcss->psz_cachefile[0] = '\0';
550 goto nocache;
552 i += sprintf( dvdcss->psz_cachefile + i, "/");
554 /* Pointer to the filename we will use. */
555 dvdcss->psz_block = dvdcss->psz_cachefile + i;
557 print_debug( dvdcss, "using CSS key cache dir: %s",
558 dvdcss->psz_cachefile );
560 nocache:
562 #if !defined(WIN32) && !defined(SYS_OS2)
563 if( psz_raw_device != NULL )
565 _dvdcss_raw_open( dvdcss, psz_raw_device );
567 #endif
569 /* Seek at the beginning, just for safety. */
570 dvdcss->pf_seek( dvdcss, 0 );
572 return dvdcss;
576 * \brief Return a string containing the latest error that occurred in the
577 * given \e libdvdcss instance.
579 * \param dvdcss a \e libdvdcss instance.
580 * \return a null-terminated string containing the latest error message.
582 * This function returns a constant string containing the latest error that
583 * occurred in \e libdvdcss. It can be used to format error messages at your
584 * convenience in your application.
586 LIBDVDCSS_EXPORT char * dvdcss_error ( dvdcss_t dvdcss )
588 return dvdcss->psz_error;
592 * \brief Seek in the disc and change the current key if requested.
594 * \param dvdcss a \e libdvdcss instance.
595 * \param i_blocks an absolute block offset to seek to.
596 * \param i_flags #DVDCSS_NOFLAGS, optionally ored with one of #DVDCSS_SEEK_KEY
597 * or #DVDCSS_SEEK_MPEG.
598 * \return the new position in blocks, or a negative value in case an error
599 * happened.
601 * This function seeks to the requested position, in logical blocks.
603 * You typically set \p i_flags to #DVDCSS_NOFLAGS when seeking in a .IFO.
605 * If #DVDCSS_SEEK_MPEG is specified in \p i_flags and if \e libdvdcss finds it
606 * reasonable to do so (ie, if the dvdcss method is not "title"), the current
607 * title key will be checked and a new one will be calculated if necessary.
608 * This flag is typically used when reading data from a VOB.
610 * If #DVDCSS_SEEK_KEY is specified, the title key will be always checked,
611 * even with the "title" method. This is equivalent to using the now
612 * deprecated dvdcss_title() call. This flag is typically used when seeking
613 * in a new title.
615 LIBDVDCSS_EXPORT int dvdcss_seek ( dvdcss_t dvdcss, int i_blocks, int i_flags )
617 /* title cracking method is too slow to be used at each seek */
618 if( ( ( i_flags & DVDCSS_SEEK_MPEG )
619 && ( dvdcss->i_method != DVDCSS_METHOD_TITLE ) )
620 || ( i_flags & DVDCSS_SEEK_KEY ) )
622 /* check the title key */
623 if( _dvdcss_title( dvdcss, i_blocks ) )
625 return -1;
629 return dvdcss->pf_seek( dvdcss, i_blocks );
633 * \brief Read from the disc and decrypt data if requested.
635 * \param dvdcss a \e libdvdcss instance.
636 * \param p_buffer a buffer that will contain the data read from the disc.
637 * \param i_blocks the amount of blocks to read.
638 * \param i_flags #DVDCSS_NOFLAGS, optionally ored with #DVDCSS_READ_DECRYPT.
639 * \return the amount of blocks read, or a negative value in case an
640 * error happened.
642 * This function reads \p i_blocks logical blocks from the DVD.
644 * You typically set \p i_flags to #DVDCSS_NOFLAGS when reading data from a
645 * .IFO file on the DVD.
647 * If #DVDCSS_READ_DECRYPT is specified in \p i_flags, dvdcss_read() will
648 * automatically decrypt scrambled sectors. This flag is typically used when
649 * reading data from a .VOB file on the DVD. It has no effect on unscrambled
650 * discs or unscrambled sectors, and can be safely used on those.
652 * \warning dvdcss_read() expects to be able to write \p i_blocks *
653 * #DVDCSS_BLOCK_SIZE bytes in \p p_buffer.
655 LIBDVDCSS_EXPORT int dvdcss_read ( dvdcss_t dvdcss, void *p_buffer,
656 int i_blocks,
657 int i_flags )
659 int i_ret, i_index;
661 i_ret = dvdcss->pf_read( dvdcss, p_buffer, i_blocks );
663 if( i_ret <= 0
664 || !dvdcss->b_scrambled
665 || !(i_flags & DVDCSS_READ_DECRYPT) )
667 return i_ret;
670 if( ! memcmp( dvdcss->css.p_title_key, "\0\0\0\0\0", 5 ) )
672 /* For what we believe is an unencrypted title,
673 * check that there are no encrypted blocks */
674 for( i_index = i_ret; i_index; i_index-- )
676 if( ((uint8_t*)p_buffer)[0x14] & 0x30 )
678 print_error( dvdcss, "no key but found encrypted block" );
679 /* Only return the initial range of unscrambled blocks? */
680 /* or fail completely? return 0; */
681 break;
683 p_buffer = (void *) ((uint8_t *)p_buffer + DVDCSS_BLOCK_SIZE);
686 else
688 /* Decrypt the blocks we managed to read */
689 for( i_index = i_ret; i_index; i_index-- )
691 _dvdcss_unscramble( dvdcss->css.p_title_key, p_buffer );
692 ((uint8_t*)p_buffer)[0x14] &= 0x8f;
693 p_buffer = (void *) ((uint8_t *)p_buffer + DVDCSS_BLOCK_SIZE);
697 return i_ret;
701 * \brief Read from the disc into multiple buffers and decrypt data if
702 * requested.
704 * \param dvdcss a \e libdvdcss instance.
705 * \param p_iovec a pointer to an array of iovec structures that will contain
706 * the data read from the disc.
707 * \param i_blocks the amount of blocks to read.
708 * \param i_flags #DVDCSS_NOFLAGS, optionally ored with #DVDCSS_READ_DECRYPT.
709 * \return the amount of blocks read, or a negative value in case an
710 * error happened.
712 * This function reads \p i_blocks logical blocks from the DVD and writes them
713 * to an array of iovec structures.
715 * You typically set \p i_flags to #DVDCSS_NOFLAGS when reading data from a
716 * .IFO file on the DVD.
718 * If #DVDCSS_READ_DECRYPT is specified in \p i_flags, dvdcss_readv() will
719 * automatically decrypt scrambled sectors. This flag is typically used when
720 * reading data from a .VOB file on the DVD. It has no effect on unscrambled
721 * discs or unscrambled sectors, and can be safely used on those.
723 * \warning dvdcss_readv() expects to be able to write \p i_blocks *
724 * #DVDCSS_BLOCK_SIZE bytes in the buffers pointed by \p p_iovec.
725 * Moreover, all iov_len members of the iovec structures should be
726 * multiples of #DVDCSS_BLOCK_SIZE.
728 LIBDVDCSS_EXPORT int dvdcss_readv ( dvdcss_t dvdcss, void *p_iovec,
729 int i_blocks,
730 int i_flags )
732 struct iovec *_p_iovec = (struct iovec *)p_iovec;
733 int i_ret, i_index;
734 void *iov_base;
735 size_t iov_len;
737 i_ret = dvdcss->pf_readv( dvdcss, _p_iovec, i_blocks );
739 if( i_ret <= 0
740 || !dvdcss->b_scrambled
741 || !(i_flags & DVDCSS_READ_DECRYPT) )
743 return i_ret;
746 /* Initialize loop for decryption */
747 iov_base = _p_iovec->iov_base;
748 iov_len = _p_iovec->iov_len;
750 /* Decrypt the blocks we managed to read */
751 for( i_index = i_ret; i_index; i_index-- )
753 /* Check that iov_len is a multiple of 2048 */
754 if( iov_len & 0x7ff )
756 return -1;
759 while( iov_len == 0 )
761 _p_iovec++;
762 iov_base = _p_iovec->iov_base;
763 iov_len = _p_iovec->iov_len;
766 _dvdcss_unscramble( dvdcss->css.p_title_key, iov_base );
767 ((uint8_t*)iov_base)[0x14] &= 0x8f;
769 iov_base = (void *) ((uint8_t*)iov_base + DVDCSS_BLOCK_SIZE);
770 iov_len -= DVDCSS_BLOCK_SIZE;
773 return i_ret;
777 * \brief Close the DVD and clean up the library.
779 * \param dvdcss a \e libdvdcss instance.
780 * \return zero in case of success, a negative value otherwise.
782 * This function closes the DVD device and frees all the memory allocated
783 * by \e libdvdcss. On return, the #dvdcss_t is invalidated and may not be
784 * used again.
786 LIBDVDCSS_EXPORT int dvdcss_close ( dvdcss_t dvdcss )
788 dvd_title_t *p_title;
789 int i_ret;
791 /* Free our list of keys */
792 p_title = dvdcss->p_titles;
793 while( p_title )
795 dvd_title_t *p_tmptitle = p_title->p_next;
796 free( p_title );
797 p_title = p_tmptitle;
800 i_ret = _dvdcss_close( dvdcss );
802 if( i_ret < 0 )
804 return i_ret;
807 free( dvdcss->psz_device );
808 free( dvdcss );
810 return 0;
814 * Deprecated. See dvdcss_seek().
816 #undef dvdcss_title
817 LIBDVDCSS_EXPORT int dvdcss_title ( dvdcss_t dvdcss, int i_block )
819 return _dvdcss_title( dvdcss, i_block );
823 * \brief Return 1 if the DVD is scrambled, 0 otherwise.
825 * \param dvdcss a \e libdvdcss instance.
826 * \return 1 if the DVD is scrambled, 0 otherwise.
828 * This function returns whether the DVD is scrambled.
830 LIBDVDCSS_EXPORT int dvdcss_is_scrambled ( dvdcss_t dvdcss )
832 return dvdcss->b_scrambled;