add support for working with capture files (e.g. from tcpdump, ethereal, et.al.)

2 files changed, 101 insertions, 11 deletions

diff --git a/libopie2/opienet/opcap.cpp b/libopie2/opienet/opcap.cpp
index 6a3dc26..30f6208 100644
--- a/libopie2/opienet/opcap.cpp
+++ b/libopie2/opienet/opcap.cpp
@@ -823,17 +823,16 @@ OPacket* OPacketCapturer::next()
 
     if ( 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
     {
         return 0;
@@ -872,17 +871,62 @@ bool OPacketCapturer::open( const QString& name )
             _sn = new QSocketNotifier( fileno(), QSocketNotifier::Read );
             connect( _sn, SIGNAL( activated(int) ), this, SLOT( readyToReceive() ) );
         }
 
         return true;
     }
     else
     {
-        qDebug( "OPacketCapturer::open(): can't open libpcap: %s", _errbuf );
+        qDebug( "OPacketCapturer::open(): can't open libpcap with '%s': %s", (const char*) name, _errbuf );
+        return false;
+    }
+
+}
+
+
+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
 {
diff --git a/libopie2/opienet/opcap.h b/libopie2/opienet/opcap.h
index c9b0624..6c3ac6d 100644
--- a/libopie2/opienet/opcap.h
+++ b/libopie2/opienet/opcap.h
@@ -42,16 +42,17 @@ extern "C"  // work around a bpf/pcap conflict in recent headers
 #include <netinet/ether.h>
 #include <netinet/ip.h>
 #include <netinet/udp.h>
 #include <netinet/tcp.h>
 #include <time.h>
 
 /* QT */
 #include <qevent.h>
+#include <qfile.h>
 #include <qhostaddress.h>
 #include <qobject.h>
 #include <qstring.h>
 #include <qmap.h>
 
 /* OPIE */
 #include <opie2/onetutils.h>
 #include "802_11_user.h"
@@ -415,45 +416,90 @@ class OTCPPacket : public QObject
     const struct tcphdr* _tcphdr;
 };
 
 
 /*======================================================================================
  * OPacketCapturer
  *======================================================================================*/
 
+/**
+ * @brief A class based wrapper for network packet capturing.
+ *
+ * This class is the base of a high-level interface to the well known packet capturing
+ * library libpcap. ...
+ */
 class OPacketCapturer : public QObject
 {
   Q_OBJECT
 
   public:
+    /**
+     * Constructor.
+     */
     OPacketCapturer( QObject* parent = 0, const char* name = 0 );
+    /**
+     * Destructor.
+     */
     ~OPacketCapturer();
-
+    /**
+     * Setting the packet capturer to use blocking IO calls can be useful when
+     * not using the socket notifier, e.g. without an application object.
+     */
     void setBlocking( bool );
+    /**
+     * @returns true if the packet capturer uses blocking IO calls.
+     */
     bool blocking() const;
-
+    /**
+     * Closes the packet capturer. This is automatically done in the destructor.
+     */
     void close();
+    /**
+     * @returns the data link type.
+     * @see <pcap.h> for possible values.
+     */
     int dataLink() const;
+    /**
+     * @returns the filedescriptor of the packet capturer. This is only useful, if
+     * not using the socket notifier, e.g. without an application object.
+     */
     int fileno() const;
+    /**
+     * @returns the next @ref OPacket from the packet capturer.
+     * @note If blocking mode is true then this call might block.
+     */
     OPacket* next();
-    bool open( const QString& name );
+    /**
+     * Open the packet capturer to capture packets in live-mode from @a interface.
+     */
+    bool open( const QString& interface );
+    /**
+     * Open the packet capturer to capture packets in offline-mode from @a file.
+     */
+    bool open( const QFile& file );
+    /**
+     * @returns true if the packet capturer is open
+     */
     bool isOpen() const;
 
     const QMap<QString,int>& statistics() const;
 
   signals:
+    /**
+     * This signal is emitted, when a packet has been received.
+     */
     void receivedPacket( OPacket* );
 
   protected slots:
     void readyToReceive();
 
   protected:
-    QString _name;          // devicename
-    bool _open;             // check this before doing pcap calls
-    pcap_t* _pch;           // pcap library handle
-    QSocketNotifier* _sn;   // socket notifier for main loop
-    mutable char _errbuf[PCAP_ERRBUF_SIZE];
-    QMap<QString, int> _stats; // statistics;
+    QString _name;                                  // devicename
+    bool _open;                                     // check this before doing pcap calls
+    pcap_t* _pch;                                   // pcap library handle
+    QSocketNotifier* _sn;                           // socket notifier for main loop
+    mutable char _errbuf[PCAP_ERRBUF_SIZE];         // holds error strings from libpcap
+    QMap<QString, int> _stats;                      // statistics;
 };
 
 #endif // OPCAP_H