inet::Ieee80211MacProtocolDissector Class Reference

#include <Ieee80211MacProtocolDissector.h>

Inheritance diagram for inet::Ieee80211MacProtocolDissector:

Public Member Functions
virtual void	dissect (Packet *packet, const Protocol *protocol, ICallback &callback) const override
	Dissects the packet according to the protocol implemented by this ProtocolDissector. More...

Protected Member Functions
virtual const Protocol *	computeLlcProtocol (Packet *packet) const

Member Function Documentation

computeLlcProtocol()

const Protocol * inet::Ieee80211MacProtocolDissector::computeLlcProtocol ( Packet *  packet ) const

protectedvirtual

{
    if (const auto& llcTag = packet->findTag<ieee80211::LlcProtocolTag>())
        return llcTag->getProtocol();
    else if (const auto& channelTag = packet->findTag<physicallayer::Ieee80211ChannelInd>()) {
        // EtherType protocol discrimination is mandatory for deployments in the 5.9 GHz band
        if (channelTag->getChannel()->getBand() == &physicallayer::Ieee80211CompliantBands::band5_9GHz)
            return &Protocol::ieee802epd;
    }
    const auto& header = packet->peekAtFront();
    if (dynamicPtrCast<const Ieee8022LlcHeader>(header) != nullptr)
        return &Protocol::ieee8022llc;
    else if (dynamicPtrCast<const Ieee802EpdHeader>(header) != nullptr)
        return &Protocol::ieee802epd;
    else
        return nullptr;
}

Referenced by dissect().

dissect()

void inet::Ieee80211MacProtocolDissector::dissect ( Packet *  packet, const Protocol *  protocol, ICallback &  callback  ) const

overridevirtual

Dissects the packet according to the protocol implemented by this ProtocolDissector.

Implements inet::ProtocolDissector.

{
    const auto& header = packet->popAtFront<inet::ieee80211::Ieee80211MacHeader>();
    const auto& trailer = packet->popAtBack<inet::ieee80211::Ieee80211MacTrailer>(B(4));
    callback.startProtocolDataUnit(&Protocol::ieee80211Mac);
    callback.visitChunk(header, &Protocol::ieee80211Mac);
    // TODO fragmentation & aggregation
    if (auto dataHeader = dynamicPtrCast<const inet::ieee80211::Ieee80211DataHeader>(header)) {
        if (dataHeader->getMoreFragments() || dataHeader->getFragmentNumber() != 0)
            callback.dissectPacket(packet, nullptr);
        else if (dataHeader->getAMsduPresent()) {
            auto originalTrailerPopOffset = packet->getBackOffset();
            int paddingLength = 0;
            while (packet->getDataLength() > B(0)) {
                packet->setFrontOffset(packet->getFrontOffset() + B(paddingLength == 4 ? 0 : paddingLength));
                const auto& msduSubframeHeader = packet->popAtFront<ieee80211::Ieee80211MsduSubframeHeader>();
                auto msduEndOffset = packet->getFrontOffset() + B(msduSubframeHeader->getLength());
                packet->setBackOffset(msduEndOffset);
                callback.dissectPacket(packet, computeLlcProtocol(packet));
                paddingLength = 4 - B(msduSubframeHeader->getChunkLength() + B(msduSubframeHeader->getLength())).get() % 4;
                packet->setBackOffset(originalTrailerPopOffset);
                packet->setFrontOffset(msduEndOffset);
            }
        }
        else
            callback.dissectPacket(packet, computeLlcProtocol(packet));
    }
    else if (dynamicPtrCast<const inet::ieee80211::Ieee80211ActionFrame>(header))
        ASSERT(packet->getDataLength() == b(0));
    else if (dynamicPtrCast<const inet::ieee80211::Ieee80211MgmtHeader>(header))
        callback.dissectPacket(packet, &Protocol::ieee80211Mgmt);
    // TODO else if (dynamicPtrCast<const inet::ieee80211::Ieee80211ControlFrame>(header))
    else
        ASSERT(packet->getDataLength() == b(0));
    callback.visitChunk(trailer, &Protocol::ieee80211Mac);
    callback.endProtocolDataUnit(&Protocol::ieee80211Mac);
}

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

• Ieee80211MacProtocolDissector.h
• Ieee80211MacProtocolDissector.cc