Subject: Smokeping service unable to stop/restart

From: ShadowM00n <[email-masked]>
Date: Mon, 27 Jul 2020 12:46:15 -0500

Package: smokeping
Version: 2.7.3-2

First-time submitter, so please excuse and correct me on any procedural 
errors on my part.

Basically, the current version of smokeping's init service quietly fails 
to stop smokeping, and then subsequently fails to restart it because the 
process is still running.

My understanding is that between ASCII and Beowulf the service was 
altered in an attempt to improve security. In ASCII, it checked only 
that a process with a saved PID existed; in Beowulf it also tries to 
compare the invocation string to the program string in the process list. 

While this seems a reasonable idea for most daemons, smokeping seems to 
be a bit of an exception -- it runs under an interpreter (perl), and as 
such the stored PID refers to the perl process launching it; naturally, 
the process string differs from the invocation, being e.g.
"/usr/bin/perl /usr/sbin/smokeping --config=/etc/smokeping/config" while 
being launched as "/usr/sbin/smokeping --config=/etc/smokeping/config".

Given this complication, my current personal setup, and my suggestion, 
is to instead check the owner of the process against the $DAEMON_USER 
when stopping, as this is configured to be a package-specific user 
called "smokeping":

< start-stop-daemon --oknodo --stop --retry 3 --quiet --pidfile $PIDFILE --exec $DAEMON --signal 15
> start-stop-daemon --oknodo --stop --retry 3 --quiet --pidfile $PIDFILE --user $DAEMON_USER --signal 15

This seems to work well for me, though I would certainly not be opposed 
to any other working method if this is less than ideal for some reason.

---

From: Mark Hindley <[email-masked]>
Date: Tue, 28 Jul 2020 11:04:04 +0100

Control: tags -1 debian

> First-time submitter, so please excuse and correct me on any procedural 

Thanks for taking the time to report this.

> compare the invocation string to the program string in the process list. 

Your analysis seems resonable.

In Devuan this package is used directly from Debian without recompilation. In
general for packages in that category, the bug reports should go to Debian's BTS
to be fixed there as the bug will also be present in Debian.

Please could you report to [email-masked]? Once you have we can add the
forwarded bug number/URL here.

Thanks.

Mark

---

From: ShadowM00n <[email-masked]>
Date: Tue, 28 Jul 2020 12:45:04 -0500

> forwarded bug number/URL here.

I was going to do so, but I don't think this actually affects Debian.

I wanted to be sure before filing a bug with them, so I set up two VMs, 
one with stock Buster and one with stock Beowulf, both installed from 
netinstall images and without a DE. I found that despite the init files 
being identical (confirmed with md5sum) and the versions of both 
packages being 2.7.3-2 (confirmed with dpkg -s smokeping | grep 
Version), the behaviour is not -- the service actually stops correctly 
on Debian and fails to stop on Beowulf. I took a side-by-side screenshot 
showcasing all of this for reference. I can include it if it's deemed 
useful, though I'm not sure it is beyond merely confirming what I just 
wrote.

I am now uncertain how accurate my earlier analysis was given that the 
Debian system worked without my fix. Any suggestions on what else should 
be looked at?