TcpCommand

class

Control info for TCP connections. This class is to be set as control info (see cMessage::setControlInfo()) on all messages exchanged between TCP and application, in both directions. Some commands and indications (TCP_C_OPEN_xxx, TCP_I_STATUS) use subclasses.

connId identifies the connection locally within the application (internally, TCP uses the (app gate index, connId) pair to identify the socket). connId is to be chosen by the application in the open command.

Inheritance diagram

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

Extends

Name	Type	Description
cObject	(unknown -- not in documented files)

Known subclasses

Name	Type	Description
TcpAcceptCommand	class	Control info to be used to accept an available connection.
TcpAvailableInfo	class	Sent with message kind TCP_I_AVAILABLE, to let the app know about the local and remote IP address and port.
TcpConnectInfo	class	Sent with message kind TCP_I_ESTABLISHED, to let the app know about the local and remote IP address and port.
TcpErrorInfo	class	Currently not in use.
TcpOpenCommand	class	Control info to be used for active or passive TCP open.
TcpSetOptionCommand	class	Base class for TCP socket option control info classes.
TcpStatusInfo	class	Sent with message kind TCP_I_STATUS, in response to command TCP_C_STATUS. For explanation of variables, see RFC 793 or TcpStateVariables in TcpConnection.h.

Fields

Name	Type	Description
userId	int	id than can be freely used by the app

Source code

//
// Control info for TCP connections. This class is to be set as control info
// (see cMessage::setControlInfo()) on all messages exchanged between TCP and
// application, in both directions. Some commands and indications
// (TCP_C_OPEN_xxx, TCP_I_STATUS) use subclasses.
//
// connId identifies the connection locally within the application (internally,
// TCP uses the (app gate index, connId) pair to identify the socket).
// connId is to be chosen by the application in the open command.
//
//# TODO explain userId
//
// @see ~TcpCommandCode, ~TcpStatusInd, ~TcpOpenCommand, ~TcpStatusInfo, ~ITcp
//
class TcpCommand extends cObject
{
    int userId = -1;   // id than can be freely used by the app
}

File: src/inet/transportlayer/contract/tcp/TcpCommand.msg