TRelay

Description

TRelay is a program for relaying tcp/udp traffic. It is capable of:

Starting/stopping several relays, independently of each other.
Saving the relay setup to file.
Loading and starting a relay setup from file.
Limiting bandwidth. This might be useful in some situations: if you want to know how your web feels when viewed through a modem, or if you want to make sure your TCP/IP networking code can cooperate with fragmented traffic.

Screenshot (well, sort of)

TRelay has a command line interpreter. Here is an example session (italic text is text that has been typed in):

    unixprompt% ./trelay
    trelay version 1.2, Copyright 2010 Tomas Abrahamsson <tab@lysator.liu.se>
    trelay comes with ABSOLUTELY NO WARRANTY; for details type `show warranty'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show copying' for details.
    
    For help, type `help'.
    
    > start tcp-*:2222-localhost:22 {bwlimit,{56700,"bps"}}
    OK ==> 0
    > start tcp-127.0.0.1:2244-localhost:22
    OK ==> 1
    > list
    Relays:
      0    tcp-*:2222-localhost:22 {bwlimit,{56700,"bps"}}
           No open connections
      1    tcp-127.0.0.1:2244-localhost:22
           No open connections
    > save f
    OK: ok.
    > stopall
    OK. All relays stopped: stopped
    > list
    There are no running relays.
    > load f
    OK: ok.
    > list
    Relays:
      2    tcp-*:2222-localhost:22 {bwlimit,{56700,"bps"}}
           No open connections
      3    tcp-127.0.0.1:2244-localhost:22
           No open connections
    > quit
    Exiting.
    unixprompt%

Download

Download the latest version: trelay-1.2.tar.gz (27 kB).

TRelay is written in Erlang, so you might need to download and install a recent copy of Erlang on your machine first.

TRelay uses rebar as build system. Unless you already have it installed, to get started, just download the rebar self-contained escript and put it in your $PATH.

Known bugs

The command syntax is a bit uncomfortable.
Under certain, rare, circumstances, the relay has been seen to crash.
There is currently no limitation on the number of relayed connections, which means that you can run out of file descriptor resources.

Author

Tomas Abrahamsson <tab@lysator.liu.se>.

Legal issues

TRelay is distributed under the GNU General Public License.

History

version 1.2, 2010-Jun-21

Build system converted to use rebar (for escriptize functionality, mainly)
Fixed compilation warnings

version 1.1, 2000-Jun-13

Added possibility to change options on the fly and to stop single connections

version 1.0, 2000-Jun-07

First version

$Id: index.html,v 1.7 2010/06/21 19:01:07 tab Exp $

Tomas Abrahamsson <tab@lysator.liu.se>.