add sanity check for last packet when capturing from capture file

1 files changed, 2 insertions, 1 deletions

diff --git a/libopie2/opienet/opcap.cpp b/libopie2/opienet/opcap.cpp
index 04b1bb1..e362883 100644
--- a/libopie2/opienet/opcap.cpp
+++ b/libopie2/opienet/opcap.cpp
@@ -639,328 +639,329 @@ OWaveLanManagementIBSS::OWaveLanManagementIBSS( const unsigned char* end, const
 {
     qDebug( "OWaveLanManagementIBSS()" );
 }
 
 
 OWaveLanManagementIBSS::~OWaveLanManagementIBSS()
 {
 }
 
 /*======================================================================================
  * OWaveLanManagementChallenge
  *======================================================================================*/
 
 OWaveLanManagementChallenge::OWaveLanManagementChallenge( const unsigned char* end, const struct challenge_t* data, QObject* parent )
                 :QObject( parent, "802.11 Challenge" ), _data( data )
 {
     qDebug( "OWaveLanManagementChallenge()" );
 }
 
 
 OWaveLanManagementChallenge::~OWaveLanManagementChallenge()
 {
 }
 
 /*======================================================================================
  * OWaveLanDataPacket
  *======================================================================================*/
 
 OWaveLanDataPacket::OWaveLanDataPacket( const unsigned char* end, const struct ieee_802_11_data_header* data, OWaveLanPacket* parent )
                 :QObject( parent, "802.11 Data" ), _header( data )
 {
     qDebug( "OWaveLanDataPacket::OWaveLanDataPacket(): decoding frame..." );
 
     const unsigned char* payload = (const unsigned char*) data + sizeof( struct ieee_802_11_data_header );
 
     #warning The next line works for most cases, but can not be correct generally!
     if (!( ( (OWaveLanPacket*) this->parent())->duration() )) payload -= 6; // compensation for missing last address
 
     new OLLCPacket( end, (const struct ieee_802_11_802_2_header*) payload, this );
 }
 
 
 OWaveLanDataPacket::~OWaveLanDataPacket()
 {
 }
 
 
 /*======================================================================================
  * OLLCPacket
  *======================================================================================*/
 
 OLLCPacket::OLLCPacket( const unsigned char* end, const struct ieee_802_11_802_2_header* data, QObject* parent )
                 :QObject( parent, "802.11 LLC" ), _header( data )
 {
     qDebug( "OLLCPacket::OLLCPacket(): decoding frame..." );
 
     if ( !(_header->oui[0] || _header->oui[1] || _header->oui[2]) )
     {
         qDebug( "OLLCPacket::OLLCPacket(): contains an encapsulated Ethernet frame (type=%04X)", EXTRACT_16BITS( &_header->type ) );
 
         switch ( EXTRACT_16BITS( &_header->type ) ) // defined in linux/if_ether.h
         {
             case ETH_P_IP: new OIPPacket( end, (const struct iphdr*) (data+1), this ); break;
             default: qDebug( "OLLCPacket::OLLCPacket(): Unknown Encapsulation Type" );
         }
 
     }
 }
 
 
 OLLCPacket::~OLLCPacket()
 {
 }
 
 
 /*======================================================================================
  * OWaveLanControlPacket
  *======================================================================================*/
 
 OWaveLanControlPacket::OWaveLanControlPacket( const unsigned char* end, const struct ieee_802_11_control_header* data, OWaveLanPacket* parent )
                 :QObject( parent, "802.11 Data" ), _header( data )
 {
     qDebug( "OWaveLanControlPacket::OWaveLanDataControl(): decoding frame..." );
     //TODO: Implement this
 }
 
 
 OWaveLanControlPacket::~OWaveLanControlPacket()
 {
 }
 
 
 /*======================================================================================
  * OPacketCapturer
  *======================================================================================*/
 
 OPacketCapturer::OPacketCapturer( QObject* parent, const char* name )
                  :QObject( parent, name ), _name( QString::null ), _open( false ),
                  _pch( 0 ), _pcd( 0 ), _sn( 0 )
 {
 }
 
 
 OPacketCapturer::~OPacketCapturer()
 {
     if ( _open )
     {
         qDebug( "OPacketCapturer::~OPacketCapturer(): pcap still open, autoclosing." );
         close();
     }
 }
 
 
 void OPacketCapturer::setBlocking( bool b )
 {
     if ( pcap_setnonblock( _pch, 1-b, _errbuf ) != -1 )
     {
         qDebug( "OPacketCapturer::setBlocking(): blocking mode changed successfully." );
     }
     else
     {
         qDebug( "OPacketCapturer::setBlocking(): can't change blocking mode: %s", _errbuf );
     }
 }
 
 
 bool OPacketCapturer::blocking() const
 {
     int b = pcap_getnonblock( _pch, _errbuf );
     if ( b == -1 )
     {
         qDebug( "OPacketCapturer::blocking(): can't get blocking mode: %s", _errbuf );
         return -1;
     }
     return !b;
 }
 
 
 void OPacketCapturer::close()
 {
     if ( _open )
     {
         if ( _sn )
         {
             _sn->disconnect( SIGNAL( activated(int) ), this, SLOT( readyToReceive() ) );
             delete _sn;
         }
         if ( _pcd )
         {
             pcap_dump_close( _pcd );
             _pcd = 0;
         }
         pcap_close( _pch );
         _open = false;
     }
 
     qDebug( "OPacketCapturer::close() --- dumping capturing statistics..." );
     qDebug( "--------------------------------------------------" );
     for( QMap<QString,int>::Iterator it = _stats.begin(); it != _stats.end(); ++it )
         qDebug( "%s : %d", (const char*) it.key(), it.data() );
     qDebug( "--------------------------------------------------" );
 
 }
 
 
 int OPacketCapturer::dataLink() const
 {
     return pcap_datalink( _pch );
 }
 
 
 int OPacketCapturer::fileno() const
 {
     if ( _open )
     {
         return pcap_fileno( _pch );
     }
     else
     {
         return -1;
     }
 }
 
 OPacket* OPacketCapturer::next()
 {
     packetheaderstruct header;
     qDebug( "==> OPacketCapturer::next()" );
     const unsigned char* pdata = pcap_next( _pch, &header );
     qDebug( "<== OPacketCapturer::next()" );
     if ( _pcd )
         pcap_dump( (u_char*) _pcd, &header, pdata );
 
-    if ( header.len )
+    if ( pdata && header.len )
     {
         OPacket* p = new OPacket( dataLink(), header, pdata, 0 );
         // packets shouldn't be inserted in the QObject child-parent hierarchy,
         // because due to memory constraints they will be deleted as soon
         // as possible - that is right after they have been processed
         // by emit() [ see below ]
         //TODO: make gathering statistics optional, because it takes time
         p->updateStats( _stats, const_cast<QObjectList*>( p->children() ) );
 
         return p;
     }
     else
     {
+        qWarning( "OPacketCapturer::next() - no packet received!" );
         return 0;
     }
 }
 
 
 bool OPacketCapturer::open( const QString& name, const QString& filename )
 {
     if ( _open )
     {
         if ( name == _name )    // ignore opening an already openend device
         {
             return true;
         }
         else                    // close the last opened device
         {
             close();
         }
     }
 
     _name = name;
 
     // open libpcap
     pcap_t* handle = pcap_open_live( const_cast<char*>( (const char*) name ), 1024, 0, 0, &_errbuf[0] );
 
     if ( !handle )
     {
         qWarning( "OPacketCapturer::open(): can't open libpcap with '%s': %s", (const char*) name, _errbuf );
         return false;
     }
 
     qDebug( "OPacketCapturer::open(): libpcap [%s] opened successfully.", (const char*) name );
     _pch = handle;
     _open = true;
     _stats.clear();
 
     // in case we have an application object, create a socket notifier
     if ( qApp ) //TODO: I don't like this here...
     {
         _sn = new QSocketNotifier( fileno(), QSocketNotifier::Read );
         connect( _sn, SIGNAL( activated(int) ), this, SLOT( readyToReceive() ) );
     }
 
     // if requested, open a dump
     pcap_dumper_t* dump = pcap_dump_open( _pch, const_cast<char*>( (const char*) filename ) );
     if ( !dump )
     {
         qWarning( "OPacketCapturer::open(): can't open dump with '%s': %s", (const char*) filename, _errbuf );
         return false;
     }
     qDebug( "OPacketCapturer::open(): dump [%s] opened successfully.", (const char*) filename );
     _pcd = dump;
 
     return true;
 }
 
 
 bool OPacketCapturer::open( const QFile& file )
 {
     QString name = file.name();
 
     if ( _open )
     {
         close();
         if ( name == _name )    // ignore opening an already openend device
         {
             return true;
         }
         else                    // close the last opened device
         {
             close();
         }
     }
 
     _name = name;
 
     pcap_t* handle = pcap_open_offline( const_cast<char*>( (const char*) name ), &_errbuf[0] );
 
     if ( handle )
     {
         qDebug( "OPacketCapturer::open(): libpcap opened successfully." );
         _pch = handle;
         _open = true;
 
         // in case we have an application object, create a socket notifier
         if ( qApp )
         {
             _sn = new QSocketNotifier( fileno(), QSocketNotifier::Read );
             connect( _sn, SIGNAL( activated(int) ), this, SLOT( readyToReceive() ) );
         }
 
         return true;
     }
     else
     {
         qDebug( "OPacketCapturer::open(): can't open libpcap with '%s': %s", (const char*) name, _errbuf );
         return false;
     }
 
 }
 
 
 bool OPacketCapturer::isOpen() const
 {
     return _open;
 }
 
 
 void OPacketCapturer::readyToReceive()
 {
     qDebug( "OPacketCapturer::readyToReceive(): about to emit 'receivePacket(p)'" );
     OPacket* p = next();
     emit receivedPacket( p );
     // emit is synchronous - packet has been dealt with, now it's safe to delete
     delete p;
 }
 
 
 const QMap<QString,int>& OPacketCapturer::statistics() const
 {
     return _stats;
 }