Network System Laboratory - sl_relay (E) [sl_relay]

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sl_relay

sl_relay

日本語はこちら

Outline

sl_relay is a Packet Relay Server for Second Life running on Linux. It is aimed at connecting to Second Life Servers from a PC through a firewall such as might be found in a university.
sl_relay relays communication (UDP,HTTP/HTTPS) between the SIM Server and the Second Life viewer.
Note: it not only relays but also scans inside each packet. Thus when the content of a packet (URL, IP address and port number) indicate another SIM is involved, a new relay process for that SIM can be started.

sl_cache can be used with sl_relay to provide a texture data cache.
When caching UDP packets (sl_cache), the sequence number of each UDP packet is rewritten to prevent contradictions.

It is also possible to limit access to particular SIMs by using sl_relay with the Information Server (sl_info).

sl_relay is part of sl_proxy.
The current version is 1.10.1 (4 Oct. '11)

Outline of Functions.

You can execute Second Life from a PC with private IP address behind a firewall.
You can specifiy the port number for firewall access.
Access to sl_relay can be controlled.
Full HTTPS access between Viewer and Relay Server is possible. (default is HTTP)
MusicURL and MediaURL(High 23) is supported. However, it is recommended that a Web proxy be used.
External Web Proxy (e.g. squid) connection is supported. Moreover, an internal Web Proxy function is included.
OpenSim is supported. (Test version)
sl_cache connection is supported. (sl_cache is the texture cache server for sl_relay.)
When sl_cache is down or response is too slow, sl_relay automatically disconnects from the cache server after short delay.
Access to Second Life SIMs can be controlled, by Avatar, viewer machine IP or at the global SIM level through the use of white lists with sl_info.

Annoyances or Bugs.

You might see the same message two or more times in IM or chat. The cause is unknown, sorry.
A stress test of sl_relay has not been carried out.

Explanation

Over the Firewall
Cooperation with the Cache Server
Cooperation with the Information Server
Communication by HTTPS
WEB Proxy Function
When the server has two or more network interfaces
Rewrite Viewer Version
Log and Debug Mode
Security
Get Grid Information

Configuration

The default configuration file is /usr/local/etc/sl_proxy/sl_relay.conf.
It is also possible to specify an alternate configuration file using the -f option of sl_relay.
Because the configuration file is read before sl_relay does the switch to the effective user, exec user should be able to be read.
The setting of each item is described in the configuration file. Empty lines or lines starting with # are not read.

Items

Communication port with SIM Server

Communication port with Viewer

Control port of Relay Controller

HTTPS(SSL)

Access control

Etc. etc.

Execute Options

sl_relay  [-s server_name[:port]] [-p port] [-f config_file] [-u user_name]
          [-i interface_address]
          [-pid pid_file] [-l [log_file]] [-v syslog_level]
          [-cs [cache_server:port]] [-cg] [-cp]
          [-is [info_server:port]] [-wf]
          [-vs [voice_relay_server:port]]
          [-as] [-aca] [-ano]
          [-xp [web_proxy_server:porti]] [-ip [port]] [-ipx [port]] [-mm]
          [-ver version]
          [-d] [-x] [-xt] [-xu] [-xuf]
          [--version] [--help] [-h]

-s   : specify login server of Second Life. default is login.agni.lindenlab.com:443
-p   : port number that Viewer connects. default is 8100.
-f   : configuration file. default is /usr/local/etc/sl_proxy/sl_relay.conf
-u   : specify effective user.
-i   : specify Viewer side network interface IP address. 
      if your server has two or more network interfaces,
       you need to use this option.
-pid : specify pid file.
-l   : specify log file. default is /var/sl_proxy/sl_relay.log
-v   : level of syslog. default is LOG_INFO (7).

-cs  : specify sl_cache cache server. default is localhost:8200
-cg  : only get cache data. do not save data.
-cp  : only save cache data. do not get data.
                
-is  : specify sl_info infomation server. default is localhost:8086
-wf  : The access limitation to SIM by the white list is done in cooperation with sl_info.
                
-vs  : specify sl_voice_relay server. default is localhost:8088
                 
-as  : use HTTPS between Viewer and Relay Server.
-aca : confirms Second Life Server by using C:\Program Files\SecondLife\app_settings\CA.pem
-ano : no HTTPS communication. Do not use, usually. It is for OpenSim olny. (Experimental option)
                
-xp  : specify external web proxy server.
-ip  : use internal web proxy function with full access mode. 
       excute internal web proxy process. port number can be specified.
-ipx : use internal web proxy function with restricted mode. 
      excute internal web proxy process.  port number can be specified.
-mm  : relay MusicURL and MediaURL(High 23). If it is possible, to use web proxy function of viewer.
       
-ver : rewrite Viewer version. 
       Please use this temporarily only when you cannot immediately install new Viewer.
       It is dangerous to use this lasting long, and never do it!!
       
-d   : debug mode. display debug information
-x   : TCP(HTTP/HTTPS) packets are saved at working directory and UDP packet headers are printed.
-xt  : TCP(HTTP/HTTPS) packets are saved at working directory.
-xu  : UDP packet headers are printed.
-xuf : UDP packet is full dumped.
       
--version  : display Version information.
--help, -h : display this Help messages.