ptp4l generates many uds port management forward failed logs when external system uses boundary-hops value of 1

[Cole Walker]

Brief Description
-----------------
Ptp4l can flood /var/log/user.log with this error message: "uds port: management forward failed". This does not appear to degrade ptp functionality, but makes it difficult to parse the ptp logs and causes excessive log rotation.

This error log results from PTP management messages on the local network that have a boundary-hop value greater than 0 and cannot be forwarded any further by ptp4l.

Severity
--------
Provide the severity of the defect.
<Minor: System/Feature is usable with minor issue>

Steps to Reproduce
------------------
Reproduction is challenging - it appears to require multiple ptp4l nodes in the domain broadcasting ptp management messages.

Expected Behavior
------------------
Logs should not be flooded with errors when using valid ptp management messages

Actual Behavior
----------------
Excessive log errors for "uds port: management forward failed"

Reproducibility
---------------
Seen once

System Configuration
--------------------
AIO-SX

Branch/Pull Time/Commit
-----------------------
master

Last Pass
---------
Unknown - likely has always been present

Timestamp/Logs
--------------
N/A

Test Activity
-------------
Evaluation

Workaround
----------
The "uds port: management forward failed" errors do not degrade ptp4l functionality, so they can be ignored. It is not possible to disable this single log, but ptp4l can be configured with logging_level=2 to suppress all error messages. This will also hide relevant errors and warnings.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/integ/+/917874
Committed: https://opendev.org/starlingx/integ/commit/36a7f8907801f93e0410a0474ed0fd76735479cc
Submitter: "Zuul (22348)"
Branch: master

commit 36a7f8907801f93e0410a0474ed0fd76735479cc
Author: Cole Walker <email address hidden>
Date: Wed May 1 14:05:11 2024 -0400

    ptp4l: Downgrade log message about failed uds forward

    Integrate a change from upstream linuxptp to downgrade the ptp4l log
    message to debug when dus forward fails. Update the linuxptp patch
    series accordingly.

    If multiple management clients are used in the network and ptp4l
    responded at least once over UDS, it will try to forward all management
    responses received from network to the last UDS client. ptp4l doesn't
    track the messages and doesn't know if they are responses to the UDS
    client or other clients in the network. If the UDS client is no longer
    running (receiving messages on its address), ptp4l logs "uds port:
    management forward failed" error message. With frequent management
    requests in the network this can lead to flooding of the system log.

    Downgrade the error message to debug to disable it in the default log
    level.

    Test plan:
    Pass: Verify package build
    Pass: Verify ptp4l startup and basic operation
    Pass: Verfiy "uds port" message is printed as at debug level

    Closes-bug: 2064654

    Change-Id: Ic778914d834f0d022d1c9f1df218940962ef93fe
    Signed-off-by: Cole Walker <email address hidden>