TCP Client Simulation

TCP Client Simulation

A TCP client initiates a connection to a server, sends requests, and processes responses. This lesson simulates the client-side behavior of TCP communication including connection state management and data exchange.

Client Lifecycle

1. connect(host, port)  — Initiate connection (three-way handshake)
2. send(data)           — Send data to server
3. receive()            — Read response from server
4. close()              — Terminate connection (four-way teardown)

TCP Connection States (Client)

CLOSED -> SYN_SENT -> ESTABLISHED -> FIN_WAIT -> CLOSED

Simulated Network

We will simulate a network where the client connects to a server and exchanges messages. The server echoes back messages with a prefix.

Your Task

Implement a TCPClient class:

• connect(host, port) — transitions to ESTABLISHED, returns handshake log
• send(data) — queues data for sending, returns bytes queued
• receive(response) — stores a server response in the receive buffer
• getReceived() — returns all received data as an array
• close() — transitions to CLOSED, returns teardown log
• getState() — returns current connection state

Also implement simulateEcho(client, messages) that sends messages and simulates the server echoing them back with "ECHO:" prefix.