Re: [tpop3d-discuss] hostname?

[Chris Lightfoot]

On Sun, Jun 30, 2002 at 06:10:53PM +0100, Chris Elsworth wrote:
> On Sun, Jun 30, 2002 at 05:19:00PM +0200, Klaus Rene Hansen [ Sconk ] wrote:
> > how do i change the hostname (pukkelhval) to some thing else?
> > POP3< +OK <address@hidden>
> 
> I believe it uses the value from /etc/resolv.conf listed as domain:
> 
> domain  shagged.org
> 
> is what I have, and I get:
> +OK <address@hidden>

Not quite.

Firstly, you can change it using the (domain) syntax for
listener in the configuration file.

The way that the domain itself is determined is
complicated but should give plausible results in most
circumstances (this is only really relevant to
non-virtual-hosts setups).  For versions prior to 1.5.1
(in CVS), the strategy is--

    - use a named domain if present;

    - else call gethostbyaddr on the address on which
      we're listening, and use the part following the
      first `.' if present, else the whole thing;

    - if that fails call uname and use the node name
      returned by that (the same value as uname -n gives
      in the shell);

    - and if that fails (we're really scraping the bottom
      of the barrel here) it uses `x.invalid'.

For versions 1.5.1 and later, you can use the syntax

    listener: 0.0.0.0/regular-expression/

where the regex is used to obtain a `domain name' from the
address to which the client has connected:

    If \fBtpop3d\fP has been compiled with support for
    mass virtual hosting (which is the default), you may
    specify instead of a domain a POSIX extended regular
    expression enclosed in \fB//\fP; this should contain
    exactly one bracketed subexpression. In this mode,
    \fBtpop3d\fP will look up the host name of the address
    to which a client has connected, and will attempt to
    match it with the specified regular expression, and
    use the matched subexpression, if any, as the domain
    name. The match is evaluated in a case-insensitive
    sense. This feature only really makes sense if
    \fBtpop3d\fP is listening on address \fB0.0.0.0\fP
    (INADDR_ANY).

    For instance, on a host which has numerous interfaces
    with names \fBpop3.example.com\fP,
    \fBpop3.example.org\fP, etc., you could specify

        .nf
          listen-address: 0.0.0.0/^pop3\.(.*)$/
        .Sp
        .fi

    to accept incoming connections and associate them with
    the proper domains.  Note that for this to work, all
    interfaces on which connections are to be accepted
    must have functioning inverse name resolution; also,
    in this case, \fBtpop3d\fP will do a name lookup for
    each incoming connection, which may block in the event
    of a DNS failure. You may wish to create some other
    mapping -- perhaps in /etc/hosts -- to ensure that
    this does not occur.


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