libp2p interop / webrtc / browser integration

[mkg20001]

Affected Components: swarm, protocol, client, node

I've been thinking about adding webRTC support to zeronet to enable browser-standalone bundles that could enable stuff like p2p commenting without having a zeronet node.

This would however require zeronetjs to use both the zeronet-v2 protocol and the multistream (libp2p) protocol (possibly on the same port)

My ideas:

• Detect the client type based on the response (v2 handshake or /multistream/1.0.0) and then use appropriate client (multistream or zeronet-v2)
  • Pros:
    • Same port
  • Cons:
    • Ugly hacks required
    • Different dialing functions required
    • Only multistream server and zn client sent data first so it's hard to detect the client type in advance (possible solution: embed the type of the client in the multiaddr)
• Different ports and multistream emulation:
  • Pros:
    • Easier to understand
  • Cons:
    • 2 swarms required (awful to implement and maintain)
    • More announces required (both ports need to be advertised)
    • libp2p port cannot be announced on trackers as trackers do not store the client type
• Detect the client type and emulate as /zn/2 multistream if client is zeronet-v2
  • Pros:
    • Same port
    • Fully libp2p
    • Same dialing function
  • Cons:
    • Special parameter for calling without multistream (reverse-multistream-emulation) required
    • Only multistream server and zn client sent data first so it's hard to detect the client type in advance (possible solution: embed the type of the client in the multiaddr)

[mkg20001]

New final plan (extends existing plan):

• Make zeronet-protocol create /zn/2/CMD with protocol-buffers and peerCMD(CMD) with msgpack so both can be used.
• Use /zn/2/CMD instead of client.cmd("CMD")
• Return a normal conn instead of a client

New temp plan:

• do znv2 handshake
  • If peer.libp2p
    • do libp2p/multistream handshake and muxer, crypto, etc
    • create a conn with /zn/2 as client
    • store conn with client and with libp2p flag
  • else
    • store conn
  • if proto is /zn/2
    • if !peer.libp2p
    • cb(null, client)
    • else
    • cb(null, conn.client)
  • else
    • if !peer.libp2p
      • fail with error "no libp2p support"
    • else
      • do hacky dial with proto

[mkg20001]

Browsers and clients can now talk to each other. I think the issue goal is achieved.