Move processing of PHC readings from sys_linux to hwclock, where
statistics can be collected and filtering improved.
In the PHC refclock driver accumulate the samples even if not in the
external timestamping mode to update the context which will be needed
for improved filtering.
Apparently some routers with hardware NAT acceleration have a bug
causing the kernel timestamps to be corrupted and break NTP. Similarly
to the sanity check applied to hardware timestamps, require the
kernel/driver timestamps to be within one second of the daemon timestamp
to be accepted.
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.
As a Linux-specific feature, allow sockets to be bound to a device using
the SO_BINDTODEVICE socket option. The CAP_NET_RAW capability is
required for setting the option.
In NIO_Linux_RequestTxTimestamp(), check the returned pointer and the
length of the buffer before adding the control message. This fixes an
issue reported by the Clang static analyzer.
With future kernels it may be possible to get, but not set, the HW
timestamping configuration on some specific interfaces like macvlan in
containers. This would require the admin to configure the timestamping
before starting chronyd.
If SIOCSHWTSTAMP failed on an interface, try SIOCGHWTSTAMP to check if
the current configuration matches the expected configuration and allow
the interface to be used for HW timestamping.
Don't forget to include the length of the frame check sequence (FCS) in
the RX timestamp transposition when the L2 length of the received packet
is from SCM_TIMESTAMPING_PKTINFO.
This fixes commit 934d4047f1.
Fix mismatches between the format and sign of variables passed to
printf() or scanf(), which were found in a Frama-C analysis and gcc
using the -Wformat-signedness option.
Apparently, it is possible for an interface to report all necessary
flags for HW timestamping without having a PHC. Check the PHC index to
avoid an error message in the system log saying that /dev/ptp-1 cannot
be opened.
Wait until a kernel RX timestamp is actually missing before opening the
dummy socket in order to avoid a small performance impact in case the
servers are so slow/distant that the kernel can constantly win the race.
The Linux kernel has a counter for sockets using kernel RX timestamping
and timestamps (all) received packets only when it is not zero. However,
this counter is updated asynchronously from setsockopt(). If there are
currently no other sockets using the timestamping, it is possible that a
fast server response is received before the kernel timestamping is
actually enabled after setting the socket option and sending a request.
Open a dummy socket on start to make sure there is always at least one
timestamping socket to avoid the race condition.
When sending client requests to a close and fast server, it is possible
that a response will be received before the HW transmit timestamp of
the request itself. To avoid processing of the response without the HW
timestamp, monitor events returned by select() and suspend reading of
packets from the receive queue for up to 200 microseconds. As the
requests are normally separated by at least 200 milliseconds, it is
sufficient to monitor and suspend one socket at a time.
If no rxfilter is specified in the hwtimestamp directive and the NIC
doesn't support the all or ntp filter, enable TX-only HW timestamping
with the none filter.
Add an rxfilter option to the hwtimestamp directive to select which
received packets should be timestamped. It can be set to "none", "ntp",
or "all". The default value is ntp, which falls back to all when ntp is
not supported.
New timestamping options may be available in kernel 4.13. They can be
used to get the index of the interface which timestamped incoming packet
together with its length at layer 2, enable simultaneous SW and HW TX
timestamping, and enable a new RX filter for NTP packets.
Request SW timestamps with SCM_TIMESTAMPING even if HW timestamping is
enabled. This replaces SCM_TIMESTAMP(NS) for RX and enables TX SW
timestamping on interfaces that don't support HW timestamping (or don't
have it enabled) if another interface has HW timestamping enabled.
It was never used for anything and messages in debug output already
include filenames, which can be easily grepped if there is a need
to see log messages only from a particular file.
