mgetty does dns lookups ?!?

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Hi,

On Sat, Feb 13, 1999 at 10:49:35PM +0100, Giulio wrote:
> I started named, put 127.0.0.1 in resolv.conf, just to see what those packets were looking
> for:
> 
> cu -l ttyS2   (and AT OK AT OK):
> 
> ns_req(from [127.0.0.1].1758)
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 39953
> ;; flags: rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
> ;;  cu\032-l\032ttyS2, type = A, class = IN                        <<======
> req: nlookup(cu\032-l\032ttyS2) id 39953 type=1 class=1
> req: missed 'cu\032-l\032ttyS2' as '' (cname=0)
> findns: np 0x80ab0f8 ''
> findns: 13 NS's added for ''
> ns_forw()
> .......

Actually, the culprit is "who" - GNU who insists on doing a DNS lookup for
things entered in the utmp "host" field, seemingly to complete a truncated
DNS name with the full domain or something like this.

I consider this a serious misfeature, but there's little mgetty can do
about it, except not write the "dialout" entry to /etc/utmp.

> The packets start only after I issue the first AT<ENTER>.
> The same happens for chat.
> So the packets are trying to resolve the names "cu -l ttyS2" and "chat".

That's the program name mgetty puts into utmp.ut_host.

> This only happens with mgetty in respawn; it doesn't happen with uugetty or if the serial
> line is without any getty.
> 
> What can I do?

Complain to the people that added this abomination to "who".

gert
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Gert Doering - Munich, Germany                             gert@greenie.muc.de
fax: +49-89-35655025                        gert.doering@physik.tu-muenchen.de