Msg File src/inet/networklayer/ipv4/IPv4Datagram.msg

Name	Type	Description
IPOptionClass	enum	IPv4 options class
IPOption	enum	IPv4 option types
TimestampFlag	enum	The timestamp flag uses the same numeric values as the IPv4 Protocol
IPv4Option	class	(no description)
IPv4OptionNop	class	(no description)
IPv4OptionEnd	class	(no description)
IPv4OptionRecordRoute	class	Option structure: Record Route
IPv4OptionTimestamp	class	Option structure: Timestamp
IPv4OptionStreamId	class	Option Structure: Stream ID
IPv4OptionUnknown	class	(no description)
IPv4Datagram	packet	Represents an IPv4 datagram.

Source code

//
// Copyright (C) 2000 Institut fuer Telematik, Universitaet Karlsruhe
// Copyright (C) 2004, 2009 Andras Varga
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program; if not, see <http://www.gnu.org/licenses/>.
//


import inet.common.TLVOption;
import inet.networklayer.contract.ipv4.IPv4Address;
import inet.networklayer.common.IPProtocolId;

namespace inet;

cplusplus {{
// default IPv4 header length: 20 bytes
const int IP_HEADER_BYTES = 20;

// maximum IPv4 header length (base+options): 60 = 4 * 15 bytes
const int IP_MAX_HEADER_BYTES = 60;

// option type fields
const unsigned char IPOPTION_COPY_MASK   = 0x80;
const unsigned char IPOPTION_CLASS_MASK  = 0x60;
const unsigned char IPOPTION_NUMBER_MASK = 0x1F;

// option entry number
const unsigned int MAX_IPADDR_OPTION_ENTRIES = 9;
const unsigned int MAX_TIMESTAMP_OPTION_ENTRIES = 4;

}}


//
// IPv4 options class
//
enum IPOptionClass
{
    IPOPTION_CLASS_CONTROL = 0;
    IPOPTION_CLASS_RESERVED = 1;
    IPOPTION_CLASS_DEBUGGING = 2;
    IPOPTION_CLASS_RESERVED2 = 3;
};

//
// IPv4 option types
//
enum IPOption
{
    IPOPTION_END_OF_OPTIONS = 0;
    IPOPTION_NO_OPTION = 1;
    IPOPTION_STREAM_ID = 8;

    IPOPTION_TIMESTAMP = 68;

    IPOPTION_SECURITY = 130;
    IPOPTION_LOOSE_SOURCE_ROUTING = 131;
    IPOPTION_RECORD_ROUTE = 136;
    IPOPTION_STRICT_SOURCE_ROUTING = 137;
    IPOPTION_ROUTER_ALERT = 148;

    IPOPTION_TLV_GPSR = 47;
};

//
// The timestamp flag uses the same numeric values as the IPv4 Protocol
//
enum TimestampFlag
{
    IP_TIMESTAMP_TIMESTAMP_ONLY = 0;
    IP_TIMESTAMP_WITH_ADDRESS = 1;
    IP_TIMESTAMP_SENDER_INIT_ADDRESS = 3;
}

class IPv4Option extends TLVOptionBase
{
}

class IPv4OptionNop extends IPv4Option
{
    type = IPOPTION_NO_OPTION;
    length = 1;
}

class IPv4OptionEnd extends IPv4Option
{
    type = IPOPTION_END_OF_OPTIONS;
    length = 1;
}

//
// Option structure: Record Route
//
class IPv4OptionRecordRoute extends IPv4Option
{
    // type = IPOPTION_RECORD_ROUTE;
    // type = IPOPTION_LOOSE_SOURCE_ROUTING
    // type = IPOPTION_STRICT_SOURCE_ROUTING
    // length = 3 + 4 * getRecordAddressArraySize();
    short nextAddressIdx;
    // pointer = 4 + 4 * nextAddressIdx
    IPv4Address recordAddress[];    // max size is 9
}

//
// Option structure: Timestamp
//
class IPv4OptionTimestamp extends IPv4Option
{
    type = IPOPTION_TIMESTAMP;
    // length = 4 + 4 * getRecordAddressArraySize() + 4 * getRecordTimestampArraySize();
    int flag @enum(TimestampFlag);
    short overflow;
    short nextIdx;
    // pointer = 5 + (flag == IP_TIMESTAMP_TIMESTAMP_ONLY ? 4 : 8) * nextIdx

    // use either up to 4 addresses with timestamps or
    // only up to 9 timestamps, according to the flag
    IPv4Address recordAddress[];
    simtime_t recordTimestamp[];
}

//
// Option Structure: Stream ID
//
class IPv4OptionStreamId extends IPv4Option
{
    type = IPOPTION_STREAM_ID;
    length = 4;
    short streamId;
}

class IPv4OptionUnknown extends IPv4Option
{
    // type = any
    // length = 2 + getBytesArraySize()
    uint8_t bytes[];
}


//
// Represents an IPv4 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 IPv4Datagram
{
    @customize(true);

    short version = 4;
    short headerLength = IP_HEADER_BYTES;

    IPv4Address srcAddress;
    IPv4Address destAddress;

    int transportProtocol @enum(IPProtocolId) = IP_PROT_NONE;
    short timeToLive;
    int identification;
    bool moreFragments;
    bool dontFragment;
    int fragmentOffset;         // bytes, must be multiple of 8
    int totalLengthField = -1;       // -1 means: getTotalLengthField() uses getByteLength()
    unsigned char typeOfService;  // ToS byte
    abstract int diffServCodePoint;  // maps to bits 0-5 of ToS
    abstract int explicitCongestionNotification;  // maps to bits 6-7 of ToS

    TLVOptions options; // array of option pointers, option pointers owned by datagram
}