| -rw-r--r-- | libopie2/opienet/opcap.h | 67 |
1 files changed, 50 insertions, 17 deletions
diff --git a/libopie2/opienet/opcap.h b/libopie2/opienet/opcap.h index 6bf7416..fe88e68 100644 --- a/libopie2/opienet/opcap.h +++ b/libopie2/opienet/opcap.h @@ -65,13 +65,55 @@ typedef struct pcap_pkthdr packetheaderstruct; class OPacketCapturer; class QSocketNotifier; /*====================================================================================== * OPacket - A frame on the wire *======================================================================================*/ -// FIXME how many OPackets do we've at a time? QObject seams to be a big for that usage + +/** @brief A class representing a data frame on the wire. + * + * The whole family of the packet classes are used when capturing frames from a network. + * Most standard network protocols in use share a common architecture, which mostly is + * a packet header and then the packet payload. In layered architectures, each lower layer + * encapsulates data from its upper layer - that is it + * treats the data from its upper layer as payload and prepends an own header to the packet, + * which - again - is treated as the payload for the layer below. The figure below is an + * example for how such a data frame is composed out of packets, e.g. when sending a mail. + * + * <pre> + * | User Data | == Mail Data + * | SMTP Header | User Data | == SMTP + * | TCP Header | SMTP Header | User Data | == TCP + * | IP Header | TCP Header | SMTP Header | User Data | == IP + * | MAC Header | IP Header | TCP Header | SMTP Header | User Data | == MAC + * + * </pre> + * + * The example is trimmed for simplicity, because the MAC (Medium Access Control) layer + * also contains a few more levels of encapsulation. + * Since the type of the payload is more or less independent from the encapsulating protocol, + * the header must be inspected before attempting to decode the payload. Hence, the + * encapsulation level varies and can't be deduced without actually looking into the packets. + * + * For actually working with captured frames, it's useful to identify the packets via names and + * insert them into a parent/child - relationship based on the encapsulation. This is why + * all packet classes derive from QObject. The amount of overhead caused by the QObject is + * not a problem in this case, because we're talking about a theoratical maximum of about + * 10 packets per captured frame. We need to stuff them into a searchable list anyway and the + * QObject also cares about destroying the sub-, (child-) packets. + * + * This enables us to perform a simple look for packets of a certain type: + * @code + * OPacketCapturer* pcap = new OPacketCapturer(); + * pcap->open( "eth0" ); + * OPacket* p = pcap->next(); + * OIPPacket* ip = (OIPPacket*) p->child( "IP" ); // returns 0, if no such child exists + * odebug << "got ip packet from " << ip->fromIPAddress().toString() << " to " << ip->toIPAddress().toString() << oendl; + * + */ + class OPacket : public QObject { Q_OBJECT public: OPacket( int datalink, packetheaderstruct, const unsigned char*, QObject* parent ); @@ -92,13 +134,12 @@ class OPacket : public QObject }; /*====================================================================================== * OEthernetPacket - DLT_EN10MB frame *======================================================================================*/ -//FIXME same critic as above -zecke class OEthernetPacket : public QObject { Q_OBJECT public: OEthernetPacket( const unsigned char*, const struct ether_header*, QObject* parent = 0 ); @@ -113,13 +154,13 @@ class OEthernetPacket : public QObject }; /*====================================================================================== * OWaveLanPacket - DLT_IEEE802_11 frame *======================================================================================*/ -//FIXME same + class OWaveLanPacket : public QObject { Q_OBJECT public: OWaveLanPacket( const unsigned char*, const struct ieee_802_11_header*, QObject* parent = 0 ); @@ -143,13 +184,13 @@ class OWaveLanPacket : public QObject }; /*====================================================================================== * OWaveLanManagementPacket - type: management (T_MGMT) *======================================================================================*/ -//FIXME same as above -zecke + class OWaveLanManagementPacket : public QObject { Q_OBJECT public: OWaveLanManagementPacket( const unsigned char*, const struct ieee_802_11_mgmt_header*, OWaveLanPacket* parent = 0 ); @@ -172,13 +213,13 @@ class OWaveLanManagementPacket : public QObject }; /*====================================================================================== * OWaveLanManagementSSID *======================================================================================*/ -//FIXME is QObject necessary? -zecke + class OWaveLanManagementSSID : public QObject { Q_OBJECT public: OWaveLanManagementSSID( const unsigned char*, const struct ssid_t*, QObject* parent = 0 ); @@ -190,13 +231,13 @@ class OWaveLanManagementSSID : public QObject const struct ssid_t* _data; }; /*====================================================================================== * OWaveLanManagementRates *======================================================================================*/ -// FIXME same as above -zecke + class OWaveLanManagementRates : public QObject { Q_OBJECT public: OWaveLanManagementRates( const unsigned char*, const struct rates_t*, QObject* parent = 0 ); @@ -207,13 +248,12 @@ class OWaveLanManagementRates : public QObject }; /*====================================================================================== * OWaveLanManagementCF *======================================================================================*/ -//FIXME same.... class OWaveLanManagementCF : public QObject { Q_OBJECT public: OWaveLanManagementCF( const unsigned char*, const struct cf_t*, QObject* parent = 0 ); @@ -224,13 +264,12 @@ class OWaveLanManagementCF : public QObject }; /*====================================================================================== * OWaveLanManagementFH *======================================================================================*/ -//FIXME same class OWaveLanManagementFH : public QObject { Q_OBJECT public: OWaveLanManagementFH( const unsigned char*, const struct fh_t*, QObject* parent = 0 ); @@ -240,13 +279,13 @@ class OWaveLanManagementFH : public QObject const struct fh_t* _data; }; /*====================================================================================== * OWaveLanManagementDS *======================================================================================*/ -//FIXME same + class OWaveLanManagementDS : public QObject { Q_OBJECT public: OWaveLanManagementDS( const unsigned char*, const struct ds_t*, QObject* parent = 0 ); @@ -259,13 +298,12 @@ class OWaveLanManagementDS : public QObject }; /*====================================================================================== * OWaveLanManagementTim *======================================================================================*/ -//FIXME guess what? class OWaveLanManagementTim : public QObject { Q_OBJECT public: OWaveLanManagementTim( const unsigned char*, const struct tim_t*, QObject* parent = 0 ); @@ -276,13 +314,12 @@ class OWaveLanManagementTim : public QObject }; /*====================================================================================== * OWaveLanManagementIBSS *======================================================================================*/ -//FIXME same as above ( Qobject ) class OWaveLanManagementIBSS : public QObject { Q_OBJECT public: OWaveLanManagementIBSS( const unsigned char*, const struct ibss_t*, QObject* parent = 0 ); @@ -325,13 +362,13 @@ class OWaveLanDataPacket : public QObject const struct ieee_802_11_data_header* _header; }; /*====================================================================================== * OWaveLanControlPacket - type: control (T_CTRL) *======================================================================================*/ -// Qobject needed? + class OWaveLanControlPacket : public QObject { Q_OBJECT public: OWaveLanControlPacket( const unsigned char*, const struct ieee_802_11_control_header*, OWaveLanPacket* parent = 0 ); @@ -342,31 +379,28 @@ class OWaveLanControlPacket : public QObject }; /*====================================================================================== * OLLCPacket - IEEE 802.2 Link Level Control *======================================================================================*/ -// QObject needed? class OLLCPacket : public QObject { Q_OBJECT public: OLLCPacket( const unsigned char*, const struct ieee_802_11_802_2_header* data, QObject* parent = 0 ); virtual ~OLLCPacket(); private: - //FIXME how to get that header? const struct ieee_802_11_802_2_header* _header; }; /*====================================================================================== * OIPPacket *======================================================================================*/ -// Qobject as baseclass? class OIPPacket : public QObject { Q_OBJECT public: OIPPacket( const unsigned char*, const struct iphdr*, QObject* parent = 0 ); @@ -387,13 +421,13 @@ class OIPPacket : public QObject const struct iphdr* _iphdr; }; /*====================================================================================== * OUDPPacket *======================================================================================*/ -// QObject? + class OUDPPacket : public QObject { Q_OBJECT public: OUDPPacket( const unsigned char*, const struct udphdr*, QObject* parent = 0 ); @@ -407,13 +441,12 @@ class OUDPPacket : public QObject }; /*====================================================================================== * OTCPPacket *======================================================================================*/ -// Qobect needed? class OTCPPacket : public QObject { Q_OBJECT public: OTCPPacket( const unsigned char*, const struct tcphdr*, QObject* parent = 0 ); |