inet::PacketDissector Class Reference

This class provides efficient general purpose packet dissection. More...

#include <PacketDissector.h>

Classes
class	ChunkBuilder
class	ICallback
class	PduTreeBuilder
class	ProtocolDataUnit
class	ProtocolDissectorCallback

Public Member Functions
	PacketDissector (const ProtocolDissectorRegistry &protocolDissectorRegistry, ICallback &callback)
void	dissectPacket (Packet *packet) const
	Dissects the given packet according to the attached PacketProtocolTag. More...
void	dissectPacket (Packet *packet, const Protocol *protocol, b extraFrontOffset=b(0), b extraBackOffset=b(0)) const
	Dissects the given packet of the provided protocol. More...

Protected Member Functions
void	doDissectPacket (Packet *packet, const Protocol *protocol) const

Protected Attributes
const ProtocolDissectorRegistry &	protocolDissectorRegistry
ICallback &	callback

Detailed Description

This class provides efficient general purpose packet dissection.

Packet dissection may be useful for printing packet details, filter packets, finding information in a packet deep down.

The supported protocols are provided by a ProtocolDissectorRegistry. The packet dissection algorithm calls the visitChunk() method of the provided PacketDissector::ICallback for each protocol specific chunk found in the packet. The chunks are passed to the method in the order they appear in the packet from left to right using their most specific protocol dependent form.

Constructor & Destructor Documentation

PacketDissector()

inet::PacketDissector::PacketDissector	(	const ProtocolDissectorRegistry &	protocolDissectorRegistry,
		ICallback &	callback
	)

                                                                                                                :
    protocolDissectorRegistry(protocolDissectorRegistry),
    callback(callback)
{
}

Member Function Documentation

dissectPacket() [1/2]

void inet::PacketDissector::dissectPacket

(

Packet *

packet

)

const

Dissects the given packet according to the attached PacketProtocolTag.

{
    const auto& packetProtocolTag = packet->findTag<PacketProtocolTag>();
    auto protocol = packetProtocolTag != nullptr ? packetProtocolTag->getProtocol() : nullptr;
    if (packetProtocolTag != nullptr)
        dissectPacket(packet, protocol, packetProtocolTag->getFrontOffset(), packetProtocolTag->getBackOffset());
    else
        dissectPacket(packet, protocol);
}

Referenced by inet::Packet::getDissection(), inet::BehaviorAggregateClassifier::PacketDissectorCallback::matches(), inet::MultiFieldClassifier::PacketDissectorCallback::matches(), inet::PacketFilter::matches(), inet::PacketPrinter::printPacket(), and inet::PacketDeserializer::processPacket().

dissectPacket() [2/2]

void inet::PacketDissector::dissectPacket	(	Packet *	packet,
		const Protocol *	protocol,
		b	extraFrontOffset = b(0),
		b	extraBackOffset = b(0)
	)		const

Dissects the given packet of the provided protocol.

The packet dissection algorithm calls the visitChunk() method of the provided callback for each protocol specific chunk found in the packet.

{
    auto frontOffset = packet->getFrontOffset();
    auto backOffset = packet->getBackOffset();
    packet->setFrontOffset(frontOffset + extraFrontOffset);
    packet->setBackOffset(backOffset + extraBackOffset);
    // dissect packet data part according to protocol
    doDissectPacket(packet, protocol);
    // dissect remaining junk in packet without protocol (e.g. ethernet padding at IP level)
    if (packet->getDataLength() != b(0))
        doDissectPacket(packet, nullptr);
    ASSERT(packet->getDataLength() == b(0));
    packet->setFrontOffset(frontOffset);
    packet->setBackOffset(backOffset);
}

doDissectPacket()

void inet::PacketDissector::doDissectPacket ( Packet *  packet, const Protocol *  protocol  ) const

protected

{
    auto protocolDissector = callback.shouldDissectProtocolDataUnit(protocol) ? protocolDissectorRegistry.findProtocolDissector(protocol) : nullptr;
    if (protocolDissector == nullptr)
        protocolDissector = protocolDissectorRegistry.getProtocolDissector(nullptr);
    ProtocolDissectorCallback callback(*this);
    protocolDissector->dissect(packet, protocol, callback);
}

Referenced by dissectPacket().

Member Data Documentation

callback

ICallback& inet::PacketDissector::callback

protected

Referenced by doDissectPacket().

protocolDissectorRegistry

const ProtocolDissectorRegistry& inet::PacketDissector::protocolDissectorRegistry

protected

Referenced by doDissectPacket().

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The documentation for this class was generated from the following files:

• PacketDissector.h
• PacketDissector.cc