C++ definition

Checks the checksum values in packet headers to verify data integrity. This module extends ChecksumCheckerBase and adds the ability to specify the position of the checksum header (front or back of the packet). It processes packets by popping the checksum header, checking if the checksum value matches the expected value based on the checksum mode, and filtering out packets with invalid checksums.

<b>See also:</b> ChecksumHeaderInserter

Inheritance diagram

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Known subclasses

Name	Type	Description
EthernetFcsHeaderChecker	simple module	Checks Ethernet FCS checksums inserted as headers in packets in order to verify data integrity. This module extends ChecksumHeaderChecker and specializes it to use the "ethernet-fcs" checksum type.
InternetChecksumHeaderChecker	simple module	Checks Internet checksum headers in packets to verify data integrity. This module extends ChecksumHeaderChecker and specializes it to use the "internet" checksum type.

Extends

Name	Type	Description
ChecksumCheckerBase	simple module	Base module for checksum checkers that verify the integrity of packets. This module filters packets based on their checksum value, dropping packets with invalid checksums. It supports multiple checksum algorithms such as CRC32 and the Internet checksum, and also several checksum modes: disabled, declared correct, declared incorrect, and computed. When in computed mode, it calculates the actual checksum and compares it with the received value.

Parameters

Name	Type	Default value	Description
displayStringTextFormat	string	"dropped %d/%p pk (%k/%l)"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
backpressure	bool	false
checksumType	string	"ethernet-fcs"
headerPosition	string	"front"

Properties

Name	Value	Description
class	ChecksumHeaderChecker
display	i=block/checker

Gates

Name	Direction	Size	Description
in	input
out	output

Signals

Name	Type	Unit	Description
packetPushedIn	inet::Packet
packetPulledIn	inet::Packet
packetDropped	inet::Packet
packetPushedOut	inet::Packet
packetPulledOut	inet::Packet

Statistics

Name	Title	Source	Record	Unit	Interpolation Mode	Description
flowDroppedPacketLengths	flow specific dropped packet lengths	packetLength(demuxFlow(packetDropped))	sum, histogram, vector	b	none	the statistical value is the flow specific length of the dropped packet
incomingDataRate	incoming data rate	throughput(merge(packetPushedIn, packetPulledIn))	vector	bps	linear	the statistical value is the data rate of the incoming packets
droppedPacketLengths	dropped packet lengths	packetLength(packetDropped)	sum, histogram, vector	b	none	the statistical value is the length of the dropped packet
incomingPacketLengths	incoming packet lengths	packetLength(merge(packetPushedIn, packetPulledIn))	sum, histogram, vector	b	none	the statistical value is the length of the incoming packet
droppedDataRate	dropped data rate	throughput(packetDropped)	vector	bps	linear	the statistical value is the data rate of the dropped packets
flowOutgoingPacketLengths	flow specific outgoing packet lengths	packetLength(demuxFlow(merge(packetPushedOut, packetPulledOut)))	sum, histogram, vector	b	none	the statistical value is the flow specific length of the outgoing packet
flowDroppedDataRate	flow specific dropped data rate	throughput(demuxFlow(packetDropped))	vector	bps	linear	the statistical value is the flow specific data rate of the dropped packets
droppedPackets	dropped packets	packetDropped	count	pk		the statistical value is the dropped packet
flowIncomingDataRate	flow specific incoming data rate	throughput(demuxFlow(merge(packetPushedIn, packetPulledIn)))	vector	bps	linear	the statistical value is the flow specific data rate of the incoming packets
outgoingDataRate	outgoing data rate	throughput(merge(packetPushedOut, packetPulledOut))	vector	bps	linear	the statistical value is the data rate of the outgoing packets
outgoingPacketLengths	outgoing packet lengths	packetLength(merge(packetPushedOut, packetPulledOut))	sum, histogram, vector	b	none	the statistical value is the length of the outgoing packet
flowIncomingPacketLengths	flow specific incoming packet lengths	packetLength(demuxFlow(merge(packetPushedIn, packetPulledIn)))	sum, histogram, vector	b	none	the statistical value is the flow specific length of the incoming packet
flowOutgoingDataRate	flow specific outgoing data rate	throughput(demuxFlow(merge(packetPushedOut, packetPulledOut)))	vector	bps	linear	the statistical value is the flow specific data rate of the outgoing packets
incomingPackets	incoming packets	merge(packetPushedIn, packetPulledIn)	count	pk		the statistical value is the incoming packet
outgoingPackets	outgoing packets	merge(packetPushedOut, packetPulledOut)	count	pk		the statistical value is the outgoing packet

Source code

//
// Checks the checksum values in packet headers to verify data integrity. 
// This module extends ChecksumCheckerBase and adds the ability to specify
// the position of the checksum header (front or back of the packet). It processes
// packets by popping the checksum header, checking if the checksum value matches the
// expected value based on the checksum mode, and filtering out packets with invalid
// checksums.
//
// @see ChecksumHeaderInserter
//
simple ChecksumHeaderChecker extends ChecksumCheckerBase
{
    parameters:
        string headerPosition @enum("front","back") = default("front");
        @class(ChecksumHeaderChecker);
}

File: src/inet/protocolelement/checksum/ChecksumHeaderChecker.ned

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