[Dnsmasq-discuss] dnsmasq exists with sigterm following bootp messages

[Simon Kelley]

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Why do you think that this is BOOTP related? I can't see any evidence
that your clients are sending bootp requests.

Background: BOOTP is an old protocol that pre-dates DHCP. DHCP packets
are actually BOOTP packets with lots of extra options. From the logs,
all the packets that dnsmasq is seeing have the extra options and are
DHCP packets.

Are you sure that dnsmasq is lying? It looks to me like something is
actually sending a SIGTERM to dnsmasq and it's doing what it supposed
to do when that happens and executing an orderly shutdown. In most,
but not all of the logs, it seems that dnsmasq is getting a SIGHUP
which causes it to re-read its configuration, and then also getting
SIGTERM which causes the shutdown immediately after.

I'd be looking very carefully at whatever bit of scripting is sending
those SIGHUPs and seeing if it can also send SIGTERM.


Cheers,

Simon.






On 07/12/15 18:41, Thomas Ballantyne wrote:
> Hi,
> 
> Any feedback here?
> 
> Thanks, Thomas
> 
> 
> On Tue, Dec 1, 2015 at 12:16 PM, Thomas Ballantyne
> <tballantyne at netflix.com> wrote:
> 
>> Hi Simon,
>> 
>> Seeing an issue where BOOTP messages are crashing dnsmasq.
>> dnsmasq exits with a SIGTERM.
>> 
>> I tried adding
>> 
>> dhcp-ignore=bootp
>> 
>> 
>> to dnsmasq.more.conf but that did not solve the problem.
>> 
>> I've tested on Ubuntu 14.0.4, with dnsmasq 2.75.
>> 
>> 
>> We run dnsmasq within a virtual machine image of Ubuntu 14. We
>> connect devices under test (set top boxes, smart TVs, consoles,
>> etc.) to the VM via a USB dongle. The device under test attempts
>> to lease an IP address from dnsmasq on the host machine
>> (192.168.144.xx) and then connect to the Netfllix cloud
>> (10.10.xx.xx.) Our Network Agent software running on the host
>> acts like a simple two port router, reconfigures the device
>> under test, and does additional dns overrides to allow
>> connections to our test and production infrastructure.
>> 
>> We see this issue specifically when connecting a partner Smart TV
>> to the host running dnsmasq via USB dongle.  The partner TV runs
>> Linux/Android OS.  Other devices under the same configuration do
>> not show this behavior. We've reported the issue to the partner
>> as well. They indicate they do not see the issue when bypassing
>> dnsmasq. Problem happens anywhere from 30-50% of hard reboots.
>> The end result is the TV fails to lease an IP address. I've also
>> seen the USB dongle issue BOOTP messages causing dnsmasq to exit 
>> with sigterm.
>> 
>> 'service restart dnsmasq' works to bring dnsmasq back after the
>> failure.
>> 
>> I've attached a portion of the dnsmasq logs (30 lines before
>> sigterm.)
>> 
>> Anything we can do here? Let me know if I can provide more
>> detail.
>> 
>> Thanks, Thomas
>> 
>> 
>> Thomas Ballantyne Operations Engineer, Netflix
>> 
>> 
>> 
>> 
>> 
>> 
> 
> 
> 
> _______________________________________________ Dnsmasq-discuss
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> 
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