[fpc-pascal]winsock telnet proxy question #1

[adeli@adeli.fr]

you have trying  to do this under Windows ?

if your dns is missconfigured there is no correspondance with localhost 
and 127.0.0.1 !


> ok, after a lot of homework and some help from this list, i have got
> my telnet server working correctly - it can accept multiple client
> connections and pass communication to and from the clients.  (i have
> only tested it locally, but that is all i need.)  in order to make my
> proxy complete, the SAME program has to connect to another telnet
> server and pass the information to the other clients.  so my program
> needs to be a server AND a client.
> 
> i tried to write a stand-alone client just to get the feel of how to
> write functional client code, and i have come to an impasse.  i have a
> telnet server running on my pc on port 23, and i would like to connect
> to that server using my client.  so far it compiles fine, and runs
> fine, but gethostbyname ('localhost') returns nil.  here's my code
> (the error handling is infantile, i know):
> 
> __________________________________
> program client;
> 
> uses
>   winsock, crt, strings;
> 
> var
>   wsadata : twsadata;
>   sockfd : tsocket;
>   server : phostent;
>   serveraddr : tsockaddr;
>   n: integer;
>   name : pchar;
>   buffer : array[0..256] of char;
> 
> function buildaddr(family: smallint; port: u_short; addr: u_long):
> tsockaddr; var
>   a: tsockaddr;
> begin
>   a.sin_family:=family;
>   a.sin_port:=htons(port);
>   a.sin_addr.s_addr:=addr;
>   buildaddr:=a;
> end;
> 
> begin
>   getmem(name,sizeof('localhost')+1);
>   strcopy(name,'localhost');
> 
>   writeln('retrieving socket....');
>   sockfd := socket(AF_INET, SOCK_STREAM, 0);
>   if (sockfd = INVALID_SOCKET) then halt;
> 
>   writeln('getting host name....',name);
>   server := gethostbyname(name);
>   if server=nil then halt;  // PROGRAM HALTS HERE
> 
>   writeln('building address....');
>   serveraddr:=buildaddr(AF_INET, 23, u_long(server^.h_addr));
> 
>   writeln('connecting socket....');
>   if (connect(sockfd,serveraddr,sizeof(serveraddr))<0) then halt;
> 
>   n:=recv(sockfd,buffer,255,0);
>   writeln(buffer);
> 
>   closesocket(sockfd);
>   freemem(name);
>   wsacleanup;
> end.
> __________________________________
> 
> why doesn't it find the host for 'localhost' - isn't that a correct
> host name?  also, any other style and/or coding advice not related to
> gethostbyname would be appreciated.
> 
> thanks for the help,
> ron wilson.
> 
> 
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Lionel Drevon			ldrevon at adeli.fr
Adeli				http://www.adeli.fr
618 Av. Gal de Gaulle		Tel 04 78 66 11 85
69760 Limonest			Fax 04 78 66 04 33