XM

gistfile1.txt

Current Server:
 IP: 88.206.179.92
 Port: 4567

Message:

Header - 5 bytes, network order:
  Flags - 1 byte:
    SYN - 1
    ACK - 2
    FIN - 4
  ID - 2 bytes, server increments with every packet
  Size - 2 byte (including the header)

Sanity - 2 bytes, always 'XM'

Command - 4 bytes:
  'noop' - Non-operation, does nothing at all
  'stor' - Store this connection in the database
  'ping' - Keepalive ping
  'pong' - Keepalive ping response
  'conn' - Connect to another client using their id

Parameters (JSON):
  stor:
    ip (string) - The IP of your sockets private endpoint (0.0.0.0 is okay)
    port (number) - The Port of your sockets private endpoint
  conn:
    id (string) - The ID to connect to

Responses (JSON):
  stor:
    ok (bool), if true then:
      id (string) - The ID
    [error] (string) - Error message if failed
  pong:
    ok (bool)
    [error] (string)
  conn:
    ok (bool), if true then:
      public: - The public endpoint of the other client
        ip (string)
        port (number)
      private: - The private endpoint of the other client
        ip (string) - Might be "0.0.0.0", in that case use the public IP
        port (number)
    [error] (string)

For each package send a SYN, wait for a SYN|ACK and then respond with an ACK. Message data is only provided in the original SYN message, the SYN|ACK and ACK only uses the packet ID.
If a SYN|ACK is not given, resend the packet five times with an interval of five seconds, if you still don't get a response assume the connection died.

Sample packages where '->' denotes a sent package, and '<-' denotes a received package:
-> \x01\x00\x01\x00\x2aXMstor{"ip":"127.0.0.1","port":12345}
<- \x03\x00\x01\x00\x24XMstor{"ok":true,"id":"screen"}
-> \x02\x00\x01\x00\x05XM
-> \x01\x00\x02\x00\x0bXMping
<- \x03\x00\x02\x00\x16XMpong{"ok":true}
-> \x02\x00\x02\x00\x05XM
-> \x01\x00\x03\x00\x00XMconn{"id":"bathtub"}
<- \x03\x00\x03\x00\x67XMconn{"ok":true,"private":{"ip":"0.0.0.0","port":12345},"public":{"ip":"127.0.0.1","port":54321}}
-> \x02\x00\x03\x00\x05XM
-> \x04\x00\x04\x00\x05XM
<- \x06\x00\x04\x00\x05XM
(Server has closed connection)