Re: DO broadcast

[Chris B. Vetter]

On 15 Jul 2003 01:52:50 +0200
Damien Genet <damien.genet@free.fr> wrote:
> Le jeu 10/07/2003 à 16:47, Richard Frith-Macdonald a écrit :
> > No ... there is no API for that.  What you normally do is ask for a 
> > connection to a service, giving an asterisk as the host name , and
> > you will get a connection to one of the servers ... no guarantee of
> > which one.
> That was our point, there is currently no way do get the list of local
> servers registered with the same name, what would be a clean way to do
> this ?

Rendezvous/ZeroConf

> In fact we are trying to have several instances of a game server on
> the local network, and list all of them. Maybe there is a better way
> to achieve this ?

Rendezvous/ZeroConf

Basically, what you would do is let your game server create a message,
eg. "MyHostName TheGameName NetProto OnPort" (like "foo bar tcp 666")
and have it broadcast 'into' the network via multicast.
(technically incorrect, but essentially how it works)

You still would have to worry about malicious users, eg. someone that
would broadcast being a valid server to connect to, but instead your
machine gets attacked. Well, if you're paranoid enough (and even if
you're not really ;-) you get the idea what can be done...

Unfortunately there's no Rendezvous available for GNUstep (yet...).
Some source is available from Apple's web site, that shows how a
multicast DNS proxy would work.
Similar projects are 'mdnsd' and 'liaisond' (sp?)

-- 
Chris