Update the support for NTP over PTP to the latest specification
(currently in the RFC editor queue). Switch the NTP TLV to the
organization-specific TLV using the IANA OUI and assigned TLV
subtype 0x1. The Network Correction extension field has been
assigned type 0x10A. The extfield option accepts F324 as an alias
for 10A to not break existing configurations. Drop the experimental
status.
Add ptpdomain directive to set the domain number of transmitted and
accepted NTP-over-PTP messages. It might need to be changed in networks
using a PTP profile with the same domain number. The default domain
number of 123 follows the current NTP-over-PTP specification.
Following the latest version of the draft, accept NTP messages in both
PTPv2 and PTPv2.1 messages, accept sync messages in addition to delay
request messages, and check the minorSdoId field in PTPv2.1 messages.
Transmitted messages are still PTPv2 delay requests.
Don't switch to the organization-specific TLV yet. Wait for the NTP TLV
subtype and Network Correction extension field to be assigned by IANA to
avoid an additional break in compatibility.
Allow NTP messages to be exchanged as a payload of PTP messages to
enable full hardware timestamping on NICs that can timestamp PTP packets
only. Implemented is the protocol described in this draft (version 00):
https://datatracker.ietf.org/doc/draft-mlichvar-ntp-over-ptp/
This is an experimental feature. It can be changed or removed in future.
The used PTP domain is 123 and the NTP TLV type is 0x2023 from the "do
not propagate" experimental range.
The ptpport directive enables NTP-over-PTP as a server and as a client
for all sources that have the port option set to the PTP port. The port
should be the PTP event port (319) to trigger timestamping in the
hardware.
The implementation is contained to ntp_io. It is transparent to
ntp_core.
