Trust - TCP Implementation

This is a TCP implementation based on RFC 793 https://www.rfc-editor.org/rfc/rfc793.html

How to Run

Step 1: Start the Server

In one terminal, run the server script:

./run.sh

The server will start and listen for TCP connections on the tun0 interface.

Step 2: Monitor Network Traffic with tshark

In another terminal, set up tshark to view the network handshake and TCP metrics:

sudo tshark -i tun0

This will capture and display all network packets on the tun0 interface, allowing you to see the TCP handshake and communication details.

Step 3: Test the Connection

in another terminal You can test the server with either of these approaches:

Option 1: Send a Single Message (One Packet)

echo "foo" | nc 192.168.0.2 8000

Expected output:

hello from rust-tcp!

This sends "foo" to the server, which reads it and closes the connection immediately.

Option 2: Interactive Connection (Multiple Packets)

nc 192.168.0.2 8000

Then type messages interactively:

read
write to me
ok good job

Key Differences

• Option 1: Sends a single message. The server reads it and stops immediately. This results in minimal packet exchange.

Learning Resources

Follow this learning path to understand the implementation:

Phase 1: Protocol Overview & Fundamentals

1. RFC 1180 - TCP/IP Protocol Suite Tutorial (Overview)

   • https://datatracker.ietf.org/doc/html/rfc1180?hl=en-US
   • Start here for a high-level understanding of TCP/IP concepts

2. YouTube: TCP Trace Files & Packet Analysis (Video)

   • https://youtu.be/xdQ9sgpkrX8?si=gzkFGBdGDD7ZlaTm
   • Learn how to read TCP traces, understand handshakes, and track packet flow between client and server

3. YouTube: TCP Deep Dive (Video)

   • https://youtu.be/rmFX1V49K8U?si=eZzkhkJYzu3nWxxK
   • Reinforces key terminologies and packet movement concepts

Phase 2: Main Implementation Reference (Core)

RFC 793 - Transmission Control Protocol ⭐ MAIN REFERENCE

• https://www.rfc-editor.org/rfc/rfc793.html
• The primary specification for this implementation
• Essential reading for understanding the code architecture

Phase 3: Supplementary

4. RFC 791 - Internet Protocol (Optional)

   • https://www.rfc-editor.org/rfc/rfc791.html
   • Provides context on the IP layer that TCP operates over

5. YouTube: TCP Retransmission (Advanced)

   • https://youtu.be/NdvWI6RH1eo?si=eU5co2Itd41YWbpH
   • Deep dive into retransmission mechanisms and timeout handling