File indexing completed on 2024-04-28 04:49:52

 /*
     SPDX-FileCopyrightText: 1998-2008 Sebastian Trueg <trueg@k3b.org>
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include <config-k3b.h>
 
 #include "k3blibdvdcss.h"
 
 #include "k3bdevice.h"
 #include "k3biso9660.h"
 #include "k3biso9660backend.h"
 
 #include <QFile>
 #include <QGlobalStatic>
 #include <QLibrary>
 #include <QPair>
 
 
 
 extern "C" {
     struct dvdcss_s;
     typedef struct dvdcss_s* dvdcss_t;
 
     dvdcss_t (*k3b_dvdcss_open)(char*);
     int (*k3b_dvdcss_close)( dvdcss_t );
     int (*k3b_dvdcss_seek)( dvdcss_t, int, int );
     int (*k3b_dvdcss_read)( dvdcss_t, void*, int, int );
 }
 
 
 Q_GLOBAL_STATIC(QLibrary, s_libDvdCss)
 
 
 
 class K3b::LibDvdCss::Private
 {
 public:
     Private()
         :dvd(0) {
     }
 
     dvdcss_t dvd;
     K3b::Device::Device* device;
     QVector< QPair<int,int> > titleOffsets;
     int currentSector;
     bool currentSectorInTitle;
 };
 
 K3b::LibDvdCss::LibDvdCss()
 {
     d = new Private();
 }
 
 
 K3b::LibDvdCss::~LibDvdCss()
 {
     close();
     delete d;
 }
 
 
 bool K3b::LibDvdCss::open( K3b::Device::Device* dev )
 {
     d->device = dev;
     dev->close();
     d->dvd = k3b_dvdcss_open( const_cast<char*>( QFile::encodeName(dev->blockDeviceName()).data() ) );
     d->currentSector = 0;
     d->currentSectorInTitle = false;
     return ( d->dvd != 0 );
 }
 
 
 void K3b::LibDvdCss::close()
 {
     if( d->dvd )
         k3b_dvdcss_close( d->dvd );
     d->dvd = 0;
 }
 
 
 int K3b::LibDvdCss::seek( int sector, int flags )
 {
     return k3b_dvdcss_seek( d->dvd, sector, flags );
 }
 
 
 int K3b::LibDvdCss::read( void* buffer, int sectors, int flags )
 {
     return k3b_dvdcss_read( d->dvd, buffer, sectors, flags );
 }
 
 
 int K3b::LibDvdCss::readWrapped( void* buffer, int firstSector, int sectors )
 {
     // 1. are we in a title?
     // 2. does a new title start in the read sector area?
     //    - see below, set title if firstSector is the first sector of a new title
     // 3. does a title end in the read sector area?
     //    3.1 does a previous title end
     //    3.2 does the title from 2. already end
 
     // we need to seek to the first sector. Otherwise we get faulty data.
     bool needToSeek = ( firstSector != d->currentSector || firstSector == 0 );
     bool inTitle = false;
     bool startOfTitle = false;
 
     //
     // Make sure we never read encrypted and unencrypted data at once since libdvdcss
     // only decrypts the whole area of read sectors or nothing at all.
     //
     for( int i = 0; i < d->titleOffsets.count(); ++i ) {
         int titleStart = d->titleOffsets[i].first;
         int titleEnd = titleStart + d->titleOffsets[i].second - 1;
 
         // update key when entrering a new title
         // FIXME: we also need this if we seek into a new title (not only the start of the title)
         if( titleStart == firstSector )
             startOfTitle = needToSeek = inTitle = true;
 
         // check if a new title or non-title area starts inside the read sector range
         if( firstSector < titleStart && firstSector+sectors > titleStart ) {
             qDebug() << "(K3b::LibDvdCss) title start inside of sector range ("
                      << firstSector << "-" << (firstSector+sectors-1)
                      << "). only reading " << (titleStart - firstSector) << " sectors up to title offset "
                      << (titleStart-1);
             sectors = titleStart - firstSector;
         }
 
         if( firstSector < titleEnd && firstSector+sectors > titleEnd ) {
             qDebug() << "(K3b::LibDvdCss) title end inside of sector range ("
                      << firstSector << "-" << (firstSector+sectors-1)
                      << "). only reading " << (titleEnd - firstSector + 1) << " sectors up to title offset "
                      << titleEnd;
             sectors = titleEnd - firstSector + 1;
             inTitle = true;
         }
 
         // is our read range part of one title
         if( firstSector >= titleStart && firstSector+sectors-1 <= titleEnd )
             inTitle = true;
     }
 
     if( needToSeek ) {
         int flags = DVDCSS_NOFLAGS;
         if( startOfTitle )
             flags = DVDCSS_SEEK_KEY;
         else if( inTitle )
             flags = DVDCSS_SEEK_MPEG;
 
         qDebug() << "(K3b::LibDvdCss) need to seek from " << d->currentSector << " to " << firstSector << " with " << flags;
 
         d->currentSector = seek( firstSector, flags );
         if( d->currentSector != firstSector ) {
             qDebug() << "(K3b::LibDvdCss) seek failed: " << d->currentSector;
             return -1;
         }
 
         qDebug() << "(K3b::LibDvdCss) seek done: " << d->currentSector;
     }
 
 
     int flags = DVDCSS_NOFLAGS;
     if( inTitle )
         flags = DVDCSS_READ_DECRYPT;
 
     int ret = read( buffer, sectors, flags );
     if( ret >= 0 )
         d->currentSector += ret;
     else
         d->currentSector = 0; // force a seek the next time
 
     return ret;
 }
 
 
 bool K3b::LibDvdCss::crackAllKeys()
 {
     //
     // Loop over all titles and crack the keys (inspired by libdvdread)
     //
     qDebug() << "(K3b::LibDvdCss) cracking all keys.";
 
     d->titleOffsets.clear();
 
     K3b::Iso9660 iso( new K3b::Iso9660DeviceBackend( d->device ) );
     iso.setPlainIso9660( true );
     if( !iso.open() ) {
         qDebug() << "(K3b::LibDvdCss) could not open iso9660 fs.";
         return false;
     }
 
 #ifdef K3B_DEBUG
     iso.debug();
 #endif
 
     const K3b::Iso9660Directory* dir = iso.firstIsoDirEntry();
 
     int title = 0;
     for( ; title < 100; ++title ) {
         QString filename;
 
         // first we get the menu vob
         if( title == 0 )
             filename = QLatin1String( "VIDEO_TS/VIDEO_TS.VOB" );
         else
             filename = QString::asprintf( "VIDEO_TS/VTS_%02d_%d.VOB", title, 0 );
 
         const K3b::Iso9660File* file = dynamic_cast<const K3b::Iso9660File*>( dir->entry( filename ) );
         if( file && file->size() > 0 ) {
             d->titleOffsets.append( qMakePair( (int)file->startSector(), (int)(file->size() / 2048U) ) );
             qDebug() << "(K3b::LibDvdCss) Get key for /" << filename << " at " << file->startSector();
             if( seek( (int)file->startSector(), DVDCSS_SEEK_KEY ) < 0 ) {
                 qDebug() << "(K3b::LibDvdCss) failed to crash key for " << filename << " at " << file->startSector();
             }
         }
 
         if( title > 0 ) {
             QPair<int,int> p;
             int vob = 1;
             for( ; vob < 100; ++vob ) {
                 filename = QString::asprintf( "VIDEO_TS/VTS_%02d_%d.VOB", title, vob );
                 file = dynamic_cast<const K3b::Iso9660File*>( dir->entry( filename ) );
                 if( file ) {
                     if( file->size() % 2048 )
                         qCritical() << "(K3b::LibDvdCss) FILESIZE % 2048 != 0!!!" << Qt::endl;
                     if( vob == 1 ) {
                         p.first = file->startSector();
                         p.second = file->size() / 2048;
                         qDebug() << "(K3b::LibDvdCss) Get key for /" << filename << " at " << file->startSector();
                         if( seek( (int)file->startSector(), DVDCSS_SEEK_KEY ) < 0 ) {
                             qDebug() << "(K3b::LibDvdCss) failed to crash key for " << filename << " at " << file->startSector();
                         }
                     }
                     else {
                         p.second += file->size() / 2048;
                     }
                 }
                 else {
                     // last vob
                     break;
                 }
             }
             --vob;
 
             // last title
             if( vob == 0 )
                 break;
 
             qDebug() << "(K3b::LibDvdCss) Title " << title << " " << vob << " vobs with length " << p.second;
             d->titleOffsets.append( p );
         }
     }
 
     --title;
 
     qDebug() << "(K3b::LibDvdCss) found " << title << " titles.";
 
     return (title > 0);
 }
 
 
 K3b::LibDvdCss* K3b::LibDvdCss::create()
 {
     if( !s_libDvdCss->isLoaded() ) {
         s_libDvdCss->setFileNameAndVersion( "dvdcss", 2 );
         s_libDvdCss->setLoadHints( QLibrary::ExportExternalSymbolsHint );
 
         if( s_libDvdCss->load() ) {
             k3b_dvdcss_open = (dvdcss_t (*)(char*))s_libDvdCss->resolve( "dvdcss_open" );
             k3b_dvdcss_close = (int (*)( dvdcss_t ))s_libDvdCss->resolve( "dvdcss_close" );
             k3b_dvdcss_seek = (int (*)( dvdcss_t, int, int ))s_libDvdCss->resolve( "dvdcss_seek" );
             k3b_dvdcss_read = (int (*)( dvdcss_t, void*, int, int ))s_libDvdCss->resolve( "dvdcss_read" );
 
             if( !k3b_dvdcss_open || !k3b_dvdcss_close || !k3b_dvdcss_seek || !k3b_dvdcss_read ) {
                 qDebug() << "(K3b::LibDvdCss) unable to resolve libdvdcss.";
                 s_libDvdCss->unload();
                 return 0;
             }
         }
         else {
             qDebug() << "(K3b::LibDvdCss) unable to load libdvdcss.";
             return 0;
         }
     }
 
     return new K3b::LibDvdCss();
 }