[avahi] Avahi daemon dies on certain hostnames

[Lennart Poettering]

On Tue, 21.03.06 17:31, Iván Sánchez Ortega (i.sanchez at mirame.net) wrote:

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> Hi,
> 
> I just discovered that the Avahi daemon dies if one machine in the network 
> handles out a response with a strange host (or domain) name.
> 
> I'm attaching the ethereal capture of the packet that "kills" the avahi 
> daemon, but this is how I can reproduce this:
> 
> - - Buy an Axis IP camera
> - - Change the camera hostname by issuing the following command:
> wget 
> http://{camera_ip_address}/axis-cgi/admin/param.cgi?action=update&Network.Bonjour.FriendlyName=fóobar
> (notice the acute in the 'ó')
> - - Run avahi-browse -at
> - - Watch how the avahi daemon dies.
> 
> I guess that setting up any other kind of mDNS responder (an avahi daemon, a 
> Bonjour-enabled Mac, etc) to return a hostname with "strange" characters 
> (anything not in 7-bit ASCII, I guess, like in "fóobar") may be able to 
> reproduce this bug. By the way, I'm running Avahi 0.6.9 here.


Hmm. While Avahi shouldn't die when such a host name appears on the
network it's primarily a bug in the axis cameras. They shouldn't send
hostnames with invalid UTF-8 characters in the first place. However, I
don't know what to do in such a case. Ignore the hostanem entirely
because it isn't valid UTF-8? Treat is as ISO8859-1 if it doesn't
validate as UTF8?

I think i will simply write a message to syslog and ignore the RRs
which contains such bogus host names. What do you think?

Lennart

-- 
Lennart Poettering; lennart [at] poettering [dot] net
ICQ# 11060553; GPG 0x1A015CC4; http://0pointer.net/lennart/