[Printing-architecture] cupsd crashes when Avahi is used

[Printing-architecture] cupsd crashes when Avahi is used

[Till Kamppeter]

Hi,

at Ubuntu many users (> 2000) hit the following bug:

https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1131854

It is an assert failure in a function of the Avahi library which makes
the CUPS daemon abort, naturally only if CUPS uses Avahi which is the
case in Ubuntu.

The Ubuntu patches on CUPS do not change anything in the Avahi support,
so the problem most probably also occurs with other distributions.

Anyone has already observed this problem? Can it be a CUPS bug? If it is
an Avahi bug, is it already known?

   Till

Re: [Printing-architecture] cupsd crashes when Avahi is used

[Michael Sweet]

Till,

Based on the bug report, it sounds like this is an internal bug of Avahi.

The fact that a production build of a library is forcing an assert is troubling - it doesn't allow the caller to perform any recovery and IMHO makes Avahi totally unsuited to production use at all.

The fix on the CUPS side is easy - bundle mDNSResponder (Apache license) with Ubuntu and build CUPS against it.  For Avahi, we'll need to get someone from Avahi to look at the issue...


On Dec 5, 2013, at 1:25 PM, Till Kamppeter <till.kamppeter@gmail.com> wrote:

> Hi,
> 
> at Ubuntu many users (> 2000) hit the following bug:
> 
> https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1131854
> 
> It is an assert failure in a function of the Avahi library which makes
> the CUPS daemon abort, naturally only if CUPS uses Avahi which is the
> case in Ubuntu.
> 
> The Ubuntu patches on CUPS do not change anything in the Avahi support,
> so the problem most probably also occurs with other distributions.
> 
> Anyone has already observed this problem? Can it be a CUPS bug? If it is
> an Avahi bug, is it already known?
> 
>   Till

_________________________________________________________
Michael Sweet, Senior Printing System Engineer, PWG Chair

Re: [Printing-architecture] cupsd crashes when Avahi is used

[Till Kamppeter]

Thanks, I have added your answer to the bug report now.

   Till


On 12/05/2013 07:48 PM, Michael Sweet wrote:
> Till,
> 
> Based on the bug report, it sounds like this is an internal bug of Avahi.
> 
> The fact that a production build of a library is forcing an assert is troubling - it doesn't allow the caller to perform any recovery and IMHO makes Avahi totally unsuited to production use at all.
> 
> The fix on the CUPS side is easy - bundle mDNSResponder (Apache license) with Ubuntu and build CUPS against it.  For Avahi, we'll need to get someone from Avahi to look at the issue...
> 
> 
> On Dec 5, 2013, at 1:25 PM, Till Kamppeter <till.kamppeter@gmail.com> wrote:
> 
>> Hi,
>>
>> at Ubuntu many users (> 2000) hit the following bug:
>>
>> https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1131854
>>
>> It is an assert failure in a function of the Avahi library which makes
>> the CUPS daemon abort, naturally only if CUPS uses Avahi which is the
>> case in Ubuntu.
>>
>> The Ubuntu patches on CUPS do not change anything in the Avahi support,
>> so the problem most probably also occurs with other distributions.
>>
>> Anyone has already observed this problem? Can it be a CUPS bug? If it is
>> an Avahi bug, is it already known?
>>
>>   Till
> 
> _________________________________________________________
> Michael Sweet, Senior Printing System Engineer, PWG Chair
>