[Dnsmasq-discuss] Leftover helper process after main process exit on FreeBSD

[Roman Bogorodskiy]

  Geert Stappers wrote:

> On Fri, Jun 13, 2025 at 02:30:47PM +0200, Roman Bogorodskiy wrote:
> > Hi,
> > 
> > I've noticed an issue on FreeBSD which I can reproduce this way:
> > 
> > # ./src/dnsmasq --interface=bridge0 --except-interface=lo0 --dhcp-range=192.168.127.2,192.168.127.254,255.255.255.0 --dhcp-script=/usr/bin/true
> > $  ps aux|grep dnsm
> > nobody     12741    0,0  0,0    14500    3128  -  I    13:43             0:00,00 ./src/dnsmasq --interface=bridge0 --except-interface=lo0 --dhcp-range=192.168.127.2,192.168.127.254,255.255.255.0 --dhcp-script=/usr/bin/true
> > root       12742    0,0  0,0    14500    3008  -  I    13:43             0:00,00 ./src/dnsmasq --interface=bridge0 --except-interface=lo0 --dhcp-range=192.168.127.2,192.168.127.254,255.255.255.0 --dhcp-script=/usr/bin/true
> > novel      12763    0,0  0,0    14192    2588  1  S+   13:44             0:00,00 grep dnsm
> > $
> 
> I mis parent PID in that output.

12741 is PID of the parent process.

> |$ ps aux | head -n 1
> |USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
> |$
> 
> 
> > # kill 12741
> 
> Not sure, but assuming "parent"

That's correct.

> So on my setup, Debian, no leftover process.

Yeah, I imagine this reproducer also needs some additional steps, I'm
not sure which though.

To provide some more details, the host I'm seeing issues on runs a few
libvirt VMs, and libvirt's networks use dnsmasq. That's how I noticed
the original problem: I cannot do a clean network restart because of the
hanging dnsmasq process.

My second host, where I cannot reproduce the problem, doesn't normally
run libvirt VMs.

Maybe some leftover state files play a role, or something like that.
But as long as I have two more or less similar systems, I probably can
find the difference which actually causes the issue to show up, unless
someone has a better idea how to do it of course.

Thanks,
Roman