Packet IPDatagram

File: src/networklayer/ipv4/IPDatagram.msg

Represents an IP datagram.

Uses the following cPacket fields:

getByteLength() / setByteLength() to represent total datagram length
hasBitError() / setBitError() to represent datagram correctness
getTimestamp() / setTimestamp (simtime) used in timestamp option

Additional length fields defined in this class are in bytes.

Only one of the option fields can exist at a time.

Usage diagram:

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Inheritance diagram:

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Fields:

Name	Type	Description
recordRoute	IPRecordRouteOption
timestampOption	IPTimestampOption
transportProtocol	int
fragmentOffset	int
diffServCodePoint	unsigned char
destAddress	IPAddress
timeToLive	short
optionCode	int
version	short
dontFragment	bool
identification	int
srcAddress	IPAddress
moreFragments	bool
headerLength	short
sourceRoutingOption	IPSourceRoutingOption	optionCode determines if strict or loose source routing

Source code:

//
// Represents an IP datagram.
//
// Uses the following cPacket fields:
//    - getByteLength() / setByteLength() to represent total datagram length
//    - hasBitError() / setBitError() to represent datagram correctness
//    - getTimestamp() / setTimestamp (simtime) used in timestamp option
//
// Additional length fields defined in this class are in bytes.
//
// Only one of the option fields can exist at a time.
//
packet IPDatagram
{
    short version = 4;
    short headerLength = IP_HEADER_BYTES;

    IPAddress srcAddress;
    IPAddress destAddress;

    int transportProtocol @enum(IPProtocolId) = IP_PROT_NONE;
    short timeToLive;
    int identification;
    bool moreFragments;
    bool dontFragment;
    int fragmentOffset;
    unsigned char diffServCodePoint;

    int optionCode @enum(IPOption) = IPOPTION_NO_OPTION;  //#FIXME modify header length when options are present
                                                         //#FIXME also: the RFC says that more than one IP-Option is allowed
    IPRecordRouteOption recordRoute;
    IPTimestampOption timestampOption;
    IPSourceRoutingOption sourceRoutingOption; // optionCode determines if strict or loose source routing
}