LightSyncProxy (udp based)

Program for remote comunication, bypassing firewall using UDP protocol.

How does it work?

Whole program is divided into three parts:

• Client (The one "outside" the network making requests into network) see folder web
• Gatweay (Available through internet, listening on public ip in selected UDP port) see folder gateway
• ClientRelay (The one "inside" local network, responding to requests) see folder service

Demo:

What it does?
Having a webserver on some hostname (public.examplehost.local), on request fro ousitde, transfer and mimic this request in local network, into "local only" host (private.examplehost.local), and return apropirate response with headers. In setup section, below, is described

Setup - Mandatory

• Create a web server (for example apache2)
• Configure two virtual hosts (pick any names, and directories)
  • ServerName public.examplehost.local
  • ServerName private.examplehost.local
  • Please refer to your webserver's configuration giude
• set hostnames in hosts file:
  • File is located:
    • On windows: %windir%\System32\drivers\etc\hosts
    • On *nix: /etc/hosts
  • Add:
    • 127.0.0.1 public.examplehost.local
    • 127.0.0.1 private.examplehost.local
• create index.php in root directory public.examplehost.local, and include web/index.php
• set all request to point into index.php for host public.examplehost.local
  • If you allow mod_rewrite, for this host, everything is pre-configured in web/.htaccess
• create some simple response for private.examplehost.local
• Configure ip addresses and ports in this project
• #TODO: descibe

Start

• Start php gateway/gateway.php
• Start php service/service.php
• Visit public.examplehost.local with web browser

Message tags:

Always a 2-byte sequences

Client

• L: Login, folowed by id and response
• P: Ping Service
• PR Ping Service, I am relay, yes?
• RR Relay request - I will be relay now for my id

Server

• N. No action, usual reply for ping
• A: Authorize! Followed by random bytes challenge
• F: Auth failed
• RY Relay confirmed

Both

• RI Relay init message (c2s 1x)
• RS Relay send message (c2s n*)

Remakrs

• First version may contain numerous bugs
• Only IPv4 Tested