Class Tcp

Used to manage the TCP state machine. Handle received packets according to current TCP connection Status. Also contains TCB (Transmission Control Block) information.

Inheritance

System.Object

Tcp

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: Cosmos.System.Network.IPv4.TCP

Assembly: Cosmos.System2.dll

Syntax

public class Tcp

Remarks

See RFC 793 for more information.

Constructors

Tcp(UInt16, UInt16, Address, Address)

Declaration

public Tcp(ushort localPort, ushort remotePort, Address localIp, Address remoteIp)

Parameters

Type	Name	Description
System.UInt16	localPort
System.UInt16	remotePort
Address	localIp
Address	remoteIp

Fields

LocalEndPoint

The local end-point.

Declaration

public EndPoint LocalEndPoint

Field Value

Type	Description
EndPoint

RemoteEndPoint

The remote end-point.

Declaration

public EndPoint RemoteEndPoint

Field Value

Type	Description
EndPoint

Status

The connection status.

Declaration

public Status Status

Field Value

Type	Description
Status

TcpWindowSize

The TCP window size.

Declaration

public const ushort TcpWindowSize = 8192

Field Value

Type	Description
System.UInt16

Methods

ProcessCloseWait(TCPPacket)

Process Close_WAIT Status.

Declaration

public void ProcessCloseWait(TCPPacket packet)

Parameters

Type	Name	Description
TCPPacket	packet	Packet to receive.

ProcessClosing(TCPPacket)

Process CLOSING Status.

Declaration

public void ProcessClosing(TCPPacket packet)

Parameters

Type	Name	Description
TCPPacket	packet	Packet to receive.

ProcessEstablished(TCPPacket)

Processes a ESTABLISHED state TCP packet.

Declaration

public void ProcessEstablished(TCPPacket packet)

Parameters

Type	Name	Description
TCPPacket	packet	The received packet.

ProcessFinWait1(TCPPacket)

Process FIN_WAIT1 Status.

Declaration

public void ProcessFinWait1(TCPPacket packet)

Parameters

Type	Name	Description
TCPPacket	packet	Packet to receive.

ProcessFinWait2(TCPPacket)

Process FIN_WAIT2 Status.

Declaration

public void ProcessFinWait2(TCPPacket packet)

Parameters

Type	Name	Description
TCPPacket	packet	Packet to receive.

ProcessListen(TCPPacket)

Processes a TCP LISTEN state packet and updates the connection status accordingly.

Declaration

public void ProcessListen(TCPPacket packet)

Parameters

Type	Name	Description
TCPPacket	packet	The incoming TCP packet.

Remarks

This method handles various types of incoming TCP packets during the LISTEN state and updates the status of the connection accordingly. If an RST packet is received, the packet is passed and no action is taken. If a FIN packet is received, the TCP connection is closed. If an ACK packet is received, the TCP connection is established. If a SYN packet is received, the TCP connection is moved to the SYN_RECEIVED state and an empty packet with the SYN and ACK flags set is sent back.

ProcessSynReceived(TCPPacket)

Processes a TCP SYN_RECEIVED state packet and updates the connection status accordingly.

Declaration

public void ProcessSynReceived(TCPPacket packet)

Parameters

Type	Name	Description
TCPPacket	packet	The incoming TCP packet.

Remarks

This method handles an incoming TCP packet during the SYN_RECEIVED state and updates the status of the connection accordingly. If an ACK packet is received with a valid AckNumber, the TCP connection is established. If the AckNumber is invalid, a reset packet is sent back with the AckNumber set to the invalid value.

ProcessSynSent(TCPPacket)

Processes a SYN_SENT state TCP packet and updates the connection state accordingly.

Declaration

public void ProcessSynSent(TCPPacket packet)

Parameters

Type	Name	Description
TCPPacket	packet	The TCP packet to process.

Remarks

If the packet has the SYN flag set, the method sets the initial receive sequence number and responds with an ACK packet if the ACK flag is also set. If the SYN flag is set but not the ACK flag, the method closes the connection and sends an error message. If the packet has only the ACK flag set, the method checks whether the acknowledgment number is within the valid range and updates the send and receive sequence numbers. If the packet has the FIN flag set, the method closes the connection. If the packet has the RST flag set, the method also closes the connection and sends an error message.