Ntpd v. ntpclient issue

Software SW help
1

Hello,

I’ve been chasing down an issue with running the NTP server on my Turris Omnia (TOS 6). I believe I found a source of confusion across the forum base and hope I could get some folks to validate my findings.

Steps to reproduce:

  • Enabled the NTP Server in LuCI → System → System → Time Syncronization. Save & Apply.

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  • Via SSH/Console, check if it is running with

netstat -a -n -l |grep 123
  • See what is running under with the name ntp: ps aux -w |grep ntp
root      4179  0.0  0.0    744    36 ?        S    13:48   0:00 /usr/sbin/ntpclient -i 600 -s -l -D -p 123 -h 0.openwrt.pool.ntp.org

I believe this is the problem! ntpclient is explictly being bound to port 123 vs. using any available port. This prevents the sysntpd daemon from starting.

For extra measure, I gave it ye old reboot and see what the logs tells me:

Jan 27 18:48:42 turris root: starting ntpclient
Jan 27 18:48:57 turris procd: Instance sysntpd::instance1 s in a crash loop 6 crashes, 0 seconds since last crash

Not the most verbose logs in terms of what, exactly, is happening but indiciative.

Continuing to poke…

If I stop the ntpclient with: killall -9 ntpclient

And then manually start the sysntpd with: /etc/init.d/sysntpd restart I can verify the server is running with netstat:

netstat -a -n -l |grep 123
udp        0      0 :::123                  :::*

And once again with ps aux -w |grep ntp

root      7245  0.0  0.0   1232   548 ?        S<   14:10   0:00 /usr/sbin/ntpd -n -N -l -I br-lan.1 -S /usr/sbin/ntpd-hotplug -p 0.openwrt.pool.ntp.org -p 1.openwrt.pool.ntp.org -p 2.openwrt.pool.ntp.org -p 3.openwrt.pool.ntp.org

SO…I think ntpclient hard coding port 123 is creating a conflict with starting the ntp daemon/server. This hard coding is observed in /etc/hotplug.d/iface/20-ntpclient and has been around for 10 years according to gitlab entries…

Potential Solutions:

  • Introduce logic to have the ntpclient bind to a different port if the server is enabled.
  • Stop binding explictly to the port all together. The manpage for ntpclient says if you don’t specify, it will use any port available

Can anyone else confirm this behavior? Do I need to open a issue in gitlab?

2

Well, in the OpenWrt documentation is stated that if you need to use ntpd, you should disable the sysntpd service or uninstall the ntpclient.

3

I had gone down that route in the past and run into update issues when the package was installed. Was trying to work my way through stock turris w/o introducing any breaking behavior.

Throwing some ideas out there…if there is a way for turris to programmatically disable the ntpclient from running or having it run after sysntpd in start up sequence (those giving priority to the server if it’s enable)?

If a user enabled “Provide NTP Server” turris will:

  • kill the active ntpclient process
  • disable the /etc/hotplug.d/iface/20-ntpclient script (e.g. move it out of the directory) or give sysntpd higher priority to start first, thus claiming ownership of the port

if a user disables “Provide NTP Server” turris will:

  • enable the /etc/hotplug.d/iface/20-ntpclient script
  • stop the sysntpd daemon
  • start the ntpdclient

I’ll look go back to a full featured ntpd server as I like the idea of having more configuration control but…wanted to share my findings/thoughts in hopes it helps someone else in the community and/or sparks an idea for the turris engineers.

4

Hi,
Just activate the option in LUCI and every thing is fine.
The service NTP is available on port 123 on the LAN
My version is 6.3.1 on Turris Omnia 1Go