Webrtc-direct end-to-end

[lchenut]

Related issue: #698
Related PRs:

• nim-libp2p: feat: webrtc-direct transport #960
• nim-webrtc:
  • SCTP: feat: sctp connection using usrsctp nim-webrtc#11
  • DataChannel: feat: datachannel protocol & datachannel connection nim-webrtc#12
  • Merged Protocols: test: merged protocols nim-webrtc#24

Preview of WebRTC-Direct Transport end-to-end

This PR introduces an untested implementation of the WebRTC-Direct transport for nim-libp2p. It leverages the nim-webrtc library (built using Mbed-TLS, Usrsctp, and in-house components) to provide a reference for how WebRTC-Direct could be implemented in Nim.

Purpose

This draft serves as a preview for the intended architecture and approach to WebRTC-Direct transport within nim-libp2p. It is not intended to be merged but rather to guide further development or refinement of the original PR.
This was done to circumvent future changes that will be made in nim-webrtc as SCTP and DataChannel are still being reviewed or worked on.

Follow these steps to test the WebRTC-Direct transport implementation:

1. Install js-libp2p:
   • Checkout a specific version if needed. I personally use this old one.
2. Run the WebRTC Browser-to-Server Example:
   • Locate the WebRTC browser-to-server example in the js-libp2p repository (e.g., in the examples directory).
   • Start the example server, and open the browser interface at the local address it provides.
3. Compile and Launch the Nim Test Program:
   • At the root of the nim-libp2p repository, compile the testwebrtc.nim example
   • When prompted, copy the multiaddress from the Nim test program and paste it into the webpage of the JS-libp2p server.
4. Interact Using WebRTC-Direct:
   • Once connected, you can establish communication via WebRTC-Direct between the js-libp2p browser instance and the nim-libp2p server.
   • You can check if everything is working correctly using wireshark and comparing it to the go implementation.