For sources specified by an IP address, keep the original address as the
source's name and pass it to the NCR instance. Allow the sources to go
through the replacement process if their address has changed.
This will be useful with NTS-KE negotiation.
The IP-based source names are now provided via cmdmon. This means
chronyc -n and -N can show two different addresses for a source.
This commit updates the FAQ with a new entry.
chronyd's Linux RTC driver (rtc_linux.c) requires the following ioctl
requests to be functional:
RTC_UIE_ON
RTC_UIE_OFF
However, a Linux system's RTC driver does not necessarily implement them,
as noted in these previous commits:
d66b2f2b24
rtc: handle RTCs that don't support interrupts
Tue Dec 10 17:45:28 2019 +0100
bff3f51d13
rtc: extend check for RTCs that don't support interrupts
Thu Dec 12 12:50:19 2019 +0100
Fortunately, the Linux kernel can be built with software emulation of
these hardware requests, by enabling the following config variable:
CONFIG_RTC_INTF_DEV_UIE_EMUL
Provides an emulation for RTC_UIE if the underlying rtc chip
driver does not expose RTC_UIE ioctls. Those requests generate
once-per-second update interrupts, used for synchronization.
The emulation code will read the time from the hardware
clock several times per second, please enable this option
only if you know that you really need it.
This commit records these facts for the benefit of the user.
GNU readline switched to GPLv3+ in version 6.0, which is incompatible
with the chrony's GPLv2 license.
Drop support for the readline library. Only editline is supported now.
The -U option can be used to start chronyd under a non-root user if it
is provided with all capabilities and access to files, directories, and
devices, needed to operate correctly in the specified configuration. It
is not recommended in cases where the configuration is unknown.
Make the precision of the system clock configurable. This can be useful
on servers using hardware timestamping to reduce the amount of noise
added to the NTP timestamps and improve stability of NTP measurements.
The directive sets the DSCP value in transmitted NTP packets, which can
be useful in local networks where switches/routers are configured to
prioritise packets with specific DSCP values.
If the daemon transmit timestamp is saved for processing of a future
response or responding in the interleaved mode, get a more accurate
timestamp right before calling NIO_SendPacket(). Avoid unnecessary
reading of the clock for the transmit timestamp in the packet (i.e.
in interleaved modes and client basic mode).
This should improve accuracy and stability when authentication is
enabled in the client and symmetric basic modes and also interleaved
modes if kernel/hardware timestamps are not available.
Add binddevice, bindacqdevice, and bindcmddevice directive to specify
the interface for binding the NTP server, NTP client, and command socket
respectively.
Instead of making the initial burst only once and immediately after
chronyd start (even when iburst is specified together with the offline
option), trigger the burst whenever the connectivity changes from
offline to online.
Add -p option to chronyd to print lines from the configuration as they
are parsed and exit. It can be used to verify the syntax and get the
whole configuration when it is split into multiple files.
Instead of sharing the NTP rate limiting with NTS-KE, specify a new
service for NTS-KE and use it in the NTS-KE server.
Add ntsratelimit directive for configuration.
Add a new field to the CLIENT_ACCESSES_BY_INDEX request to specify the
minimum number of NTP or cmdmon packets for a client to be reported.
Add -p option to the chronyc clients command to specify the threshold
(by default 0). This option can be used to minimize the number of cmdmon
requests when interested only in clients sending a large number
of requests.
Add a flag to the CLIENT_ACCESSES_BY_INDEX request to reset the
NTP/cmdmon hits/dropped counters after reporting the current values.
Add -r option to the chronyc clients command to perform the reset. This
should make it easier to find clients that send large number of requests
over short periods of time.
Add a confdirs directive to include *.conf files from multiple
directories. If a file with the same name exists in multiple
directories, only the first one in the order of the specified
directories will be included.
When authentication is enabled for an NTP source, unauthenticated NTP
sources need to be disabled or limited in selection. That might be
difficult to do when the configuration comes from different sources
(e.g. networking scripts adding servers from DHCP).
Define four modes for the source selection to consider authentication:
require, prefer, mix, ignore. In different modes different selection
options (require, trust, noselect) are added to authenticated and
unauthenticated sources.
The mode can be selected by the authselectmode directive. The mix mode
is the default. The ignore mode enables the old behavior, where all
sources are used exactly as specified in the configuration.
