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From: oleg@watson.ibm.com (Oleg Vishnepolsky)
Newsgroups: comp.protocols.kerberos
Subject: Re: Kerberos and two ethernet ports
Message-ID: <1991May31.130021.29884@watson.ibm.com>
Date: 31 May 91 13:00:21 GMT
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In  <1991May24.210757.10215@shearson.com>  viktor@shearson.com (Viktor Dukhovni) writes:
> galina@watson.ibm.com (Galina Kofman)_ writes:
>
> >In send_to_kdc.c after the socket was obtained add:
>
> >    if ( loc_host_addr == 0 ) /* static u_long loc_host_addr = 0 initially */ {
> >        if ( (loc_host_addr = gethostid()) == 0) {
>                               ^^^^^^^
>                       This is not terribly likely to return
>                       an IP address.  On systems without a harware ID
>                       the default hostid may be based on the IP address,
>                       but these tend to also have sethostid(),  which
>                       may be used by the sysadmin to set any other value.
>
>
>       To bind to the primary address one must
>
>       char name[MAXHOSTNAMELEN];
>       struct hostent *hp;
>       gethostname(name,MAXHOSTNAMELEN);
>       if ( (hp=gethostbyname(name)) == NULL ) {
>               /* error */
>               ...
>       }
>       bcopy(hp->h_addr,&loc_host_addr,sizeof(loc_host_addr));
> --
>         Viktor Dukhovni <viktor@shearson.com>       : ARPA
>                 <...!uunet!shearson.com!viktor>     : UUCP
>         388 Greenwich St., 11th floor, NY, NY 10013 : US-Post
>                 +1-(212)-464-3793                   : VOICE

True on most UNIX systems. Not true on OS/2 and VM/CMS where Galina ported
KERBEROS to. gethostid() on these systems returns an IP address.
There gethostid() approach is more efficient since no need to resolve
a name is needed.

Oleg Vishnepolsky