🚀 go-pugleaf

"Mario de Sousa Dias" <mario_d@clix.pt> writes:

> Hello everyone....
> 
> I would like to know how to write very simple client program in C using
> sockets that tries to find out in which machine the server is. This is done
> using a broadcast (the server is on the same LAN).
> 
> I know that I must use setsockopt().

How do you know that?

% man setsockopt|grep -i broad ; echo $?
1

Sending a broadcast is just using an address with a host part all 1's.

So  if  you're interface  address  is  my_addr,  and your  netmask  is
my_mask, then you can build the broadcast address with:

    int my_broadcast = (my_addr & my_mask) | ( -1 & ( ~ my_mask ))

and use this as IP address.

Check inet(3) too.

And  if  you have  FreeS/WAN  installed,  you  may use  their  library
function ipsec_broadcastof(3).

> WHEN responding to the client, The server must include it's �level�. If
> possible I'd also like to know how to implement the server code...
> 
> Thank you...


-- 
__Pascal_Bourguignon__                   http://www.informatimago.com/
----------------------------------------------------------------------
There is a fault in reality. Do not adjust your minds. -- Salman Rushdie