inet::sctp::SctpCrcInsertion Class Reference

#include <SctpCrcInsertionHook.h>

Inheritance diagram for inet::sctp::SctpCrcInsertion:

Public Member Functions
	SctpCrcInsertion ()
void	setCrcMode (CrcMode crcModeP)
void	insertCrc (const Protocol *networkProtocol, const L3Address &srcAddress, const L3Address &destAddress, const Ptr< SctpHeader > &sctpHeader, Packet *packet)
uint32_t	checksum (unsigned char const *, unsigned int)
virtual Result	datagramPreRoutingHook (Packet *packet) override
	This is the first hook called by the network protocol before it routes a datagram that was received from the lower layer. More...
virtual Result	datagramForwardHook (Packet *packet) override
	This is the second hook called by the network protocol before it sends a datagram to the lower layer. More...
virtual Result	datagramPostRoutingHook (Packet *packet) override
	This is the last hook called by the network protocol before it sends a datagram to the lower layer. More...
virtual Result	datagramLocalInHook (Packet *packet) override
	This is the last hook called by the network protocol before it sends a datagram to the upper layer. More...
virtual Result	datagramLocalOutHook (Packet *packet) override
	This is the first hook called by the network protocol before it routes a datagram that was received from the upper layer. More...
Public Member Functions inherited from inet::NetfilterBase::HookBase
virtual	~HookBase ()
void	registeredTo (INetfilter *nf)
void	unregisteredFrom (INetfilter *nf)
bool	isRegisteredHook (INetfilter *nf)
Public Member Functions inherited from inet::INetfilter::IHook
virtual	~IHook ()

Private Attributes
CrcMode	crcMode = CRC_MODE_UNDEFINED

Additional Inherited Members
Public Types inherited from inet::INetfilter::IHook
enum	Type {   PREROUTING, LOCALIN, FORWARD, POSTROUTING,   LOCALOUT }
enum	Result { ACCEPT, DROP, QUEUE, STOLEN }
Protected Attributes inherited from inet::NetfilterBase::HookBase
std::vector< INetfilter * >	netfilters

Constructor & Destructor Documentation

SctpCrcInsertion()

inet::sctp::SctpCrcInsertion::SctpCrcInsertion ( )

inline

{}

Member Function Documentation

checksum()

uint32_t inet::sctp::SctpCrcInsertion::checksum	(	unsigned char const *	,
		unsigned int
	)

datagramForwardHook()

virtual Result inet::sctp::SctpCrcInsertion::datagramForwardHook ( Packet *  datagram )

inlineoverridevirtual

This is the second hook called by the network protocol before it sends a datagram to the lower layer.

This is done after the datagramPreRoutingHook or the datagramLocalInHook is called and the datagram is routed.

Implements inet::INetfilter::IHook.

{ return ACCEPT; }

datagramLocalInHook()

virtual Result inet::sctp::SctpCrcInsertion::datagramLocalInHook ( Packet *  datagram )

inlineoverridevirtual

This is the last hook called by the network protocol before it sends a datagram to the upper layer.

This is done after the datagramPreRoutingHook is called and the datagram is routed.

Implements inet::INetfilter::IHook.

{ return ACCEPT; }

datagramLocalOutHook()

virtual Result inet::sctp::SctpCrcInsertion::datagramLocalOutHook ( Packet *  datagram )

inlineoverridevirtual

This is the first hook called by the network protocol before it routes a datagram that was received from the upper layer.

The nextHopAddress is ignored when the outputNetworkInterface is a nullptr. After this is done

Implements inet::INetfilter::IHook.

{ return ACCEPT; }

datagramPostRoutingHook()

INetfilter::IHook::Result inet::sctp::SctpCrcInsertion::datagramPostRoutingHook ( Packet *  datagram )

overridevirtual

This is the last hook called by the network protocol before it sends a datagram to the lower layer.

Implements inet::INetfilter::IHook.

{
    Enter_Method("datagramPostRoutingHook");
 
    if (packet->findTag<InterfaceInd>())
        return ACCEPT; // FORWARD
    auto networkProtocol = packet->getTag<PacketProtocolTag>()->getProtocol();
    const auto& networkHeader = getNetworkProtocolHeader(packet);
    if (networkHeader->getProtocol() == &Protocol::sctp) {
        ASSERT(!networkHeader->isFragment());
        packet->eraseAtFront(networkHeader->getChunkLength());
        auto sctpHeader = packet->removeAtFront<SctpHeader>();
        ASSERT(sctpHeader->getCrcMode() == CRC_COMPUTED);
        const L3Address& srcAddress = networkHeader->getSourceAddress();
        const L3Address& destAddress = networkHeader->getDestinationAddress();
        insertCrc(networkProtocol, srcAddress, destAddress, sctpHeader, packet);
        packet->insertAtFront(sctpHeader);
        packet->insertAtFront(networkHeader);
    }
    return ACCEPT;
}

datagramPreRoutingHook()

virtual Result inet::sctp::SctpCrcInsertion::datagramPreRoutingHook ( Packet *  datagram )

inlineoverridevirtual

This is the first hook called by the network protocol before it routes a datagram that was received from the lower layer.

The nextHopAddress is ignored when the outputNetworkInterface is nullptr.

Implements inet::INetfilter::IHook.

{ return ACCEPT; }

insertCrc()

void inet::sctp::SctpCrcInsertion::insertCrc	(	const Protocol *	networkProtocol,
		const L3Address &	srcAddress,
		const L3Address &	destAddress,
		const Ptr< SctpHeader > &	sctpHeader,
		Packet *	packet
	)

{
    sctpHeader->setCrcMode(crcMode);
    switch (crcMode) {
        case CRC_DECLARED_CORRECT:
            // if the CRC mode is declared to be correct, then set the CRC to an easily recognizable value
            sctpHeader->setCrc(0xC00D);
            break;
        case CRC_DECLARED_INCORRECT:
            // if the CRC mode is declared to be incorrect, then set the CRC to an easily recognizable value
            sctpHeader->setCrc(0xBAAD);
            break;
        case CRC_COMPUTED: {
            // if the CRC mode is computed, then compute the CRC and set it
            // this computation is delayed after the routing decision, see INetfilter hook
            sctpHeader->setCrc(0); // make sure that the CRC is 0 in the SCTP header before computing the CRC
            MemoryOutputStream sctpPacketStream;
            Chunk::serialize(sctpPacketStream, sctpHeader);
            Chunk::serialize(sctpPacketStream, packet->peekData(Chunk::PF_ALLOW_EMPTY));
            const auto& sctpPacketBytes = sctpPacketStream.getData();
            auto length = sctpPacketBytes.size();
            auto buffer = new uint8_t[length];
            std::copy(sctpPacketBytes.begin(), sctpPacketBytes.end(), (uint8_t *)buffer);
            auto crc = SctpChecksum::checksum(buffer, length);
            sctpHeader->setCrc(crc);
            delete[] buffer;
            break;
        }
        default:
            throw cRuntimeError("Unknown CRC mode");
    }
}

Referenced by datagramPostRoutingHook().

setCrcMode()

void inet::sctp::SctpCrcInsertion::setCrcMode ( CrcMode  crcModeP )

inline

{ crcMode = crcModeP; }

Member Data Documentation

crcMode

CrcMode inet::sctp::SctpCrcInsertion::crcMode = CRC_MODE_UNDEFINED

private

Referenced by insertCrc(), and setCrcMode().

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

• SctpCrcInsertionHook.h
• SctpCrcInsertionHook.cc