Add maxunreach option to NTP sources and refclocks to specify the
maximum number of polls that the source can stay selected for
synchronization when it is unreachable (i.e. no valid sample was
received in the last 8 polls).
It is an additional requirement to having at least one sample more
recent than the oldest sample of reachable sources.
The default value is 100000. Setting the option to 0 disables selection
of unreachable sources, which matches RFC 5905.
To minimize the impact of potential attacks targeting chronyc started
under root (e.g. performed by a local chronyd process running without
root privileges, a remote chronyd process, or a MITM attacker on the
network), add support for changing the effective UID/GID in chronyc
after start.
The user can be specified by the -u option, similarly to chronyd. The
default chronyc user can be changed by the --with-chronyc-user
configure option. The default value of the default chronyc user is
"root", i.e. chronyc doesn't try to change the identity by default.
The default chronyc user does not follow the default chronyd user
set by the configure --with-user option to avoid errors on systems where
chronyc is not allowed to change its UID/GID (e.g. by a SELinux policy).
When chronyc running under root binds its Unix domain socket, it needs
to change the socket permissions in order for chronyd running without
root privileges to be able to send a response to the socket.
There is a race condition between the bind() and chmod() calls. If an
attacker was able to execute arbitrary code in the chronyd process, it
might be able to wait for chronyc to be executed under root, replace the
socket with a symlink between the two calls, and cause the privileged
chronyc process to change permissions of something else, possibly
leading to a privilege escalation.
There doesn't seem to be a safe and portable way to change the socket
permissions directly. Changing the process umask could be problematic in
future with threads.
Hide the socket in two levels of subdirectories (the lower one having
a randomly generated name and not visible to the chronyd process) to
make the socket path unpredictable, and force the bind() or chmod() call
to fail if the visible upper directory is replaced.
Reported-by: Matthias Gerstner <mgerstner@suse.de>
Add an enum to describe the error in the parsed directive: missing
argument, invalid option, or invalid value.
Update the error messages in conf.c and client.c.
Add "waitunsynced" option to specify how long chronyd needs to wait
before it can activate the local reference when the clock is not
synchronized to give the configured sources a chance to synchronize the
local clock after start. The default is 300 seconds when the orphan
option is enabled (same as the ntpd's default orphanwait), 0 otherwise.
Add "waitsynced" option to specify how long it should wait when the
clock is synchronized. It is an additional requirement to the distance
and activate options.
Some assertions are written as "if (x) assert(0)" to avoid having
the text of a long argument compiled in the binary. Rewrite them
to use a new BRIEF_ASSERT macro to make the condition easier to read in
its non-negated form and make it easier to turn it back to the full-text
assert if needed.
Add two reserved fields initialized to zero to the new REQ_LOCAL3
command to allow adding more options (e.g. delay in activation) without
changing the command number again.
This option sets an activating root distance for the local reference. The
local reference will not be used until the root distance drops below the
configured value for the first time. This can be used to prevent the local
reference from being activated on a server which has never been synchronised
with an upstream server. The default value of 0.0 causes no activating
distance to be used, such that the local reference is always eligible for
activation.
If the network correction is known for both the request and response,
and their sum is not larger that the measured peer delay, allowing the
transparent clocks to be running up to 100 ppm faster than the client's
clock, apply the corrections to the NTP offset and peer delay. Don't
correct the root delay to not change the estimated maximum error.
Rename the exp1 extension field to exp_mono_root (monotonic timestamp +
root delay/dispersion) to better distinguish it from future experimental
extension fields.
The clang memory sanitizer seems to trigger on an uninitialized value
passed to format_name() when the source is a refclock, even though the
value is not used for anything. Pass 0 in this case to avoid the error.
Update the serverstats response to use the new 64-bit integers.
Don't define a new value for the response as it already had an
incompatible change since the latest release (new fields added for
timestamp counters).
In a non-tty session with chronyc it is not possible to detect the
end of the response without relying on timeouts, or separate responses
to a repeated command if using the -c option.
Add -e option to end each response with a line containing a single dot.
Add a new test for maximum delay using a long-term estimate of a
p-quantile of the peer delay. If enabled, it replaces the
maxdelaydevratio test. It's main advantage is that it is not sensitive
to outliers corrupting the minimum delay.
As it can take a large number of samples for the estimate to reach the
expected value and adapt to a new value after a network change, the
option is recommended only for local networks with very short polling
intervals.
Return with an error code from chronyc if the command is expected to
print some data and fflush() or ferror() indicates an error. This should
make it easier for scripts to detect missing data when redirected to a
file.
Use snprintf() instead of strcat() and don't try to parse commands
longer than 2048 characters to make it consistent with the chrony.conf
parser, avoid memory allocation, and not rely on the system ARG_MAX to
keep the length sane.
Allow sources to accumulate samples with the leap status set to not
synchronized. Define a new state for them to be ignored in the
selection. This is intended for sources that are never synchronized and
will be used only for stabilization.
If chronyc waitsync was started before chronyd, it would try all
addresses (Unix socket, IPv4, IPv6) and get stuck with no address, not
getting any response later when chronyd was running.
Reset the address index in open_io() when returning with failure to
allow the next call to start with the first address again.
Reported-by: Jan Mikkelsen <janm@transactionware.com>
Add "extfield F323" option to include the new extension field in
requests. If the server responds with this field, use the root
delay/dispersion and monotonic timestamp. Accumulate changes in the
offset between the monotonic and real-time receive timestamps and use
it for the correction of previous offsets in sourcestats. In the
interleaved mode, cancel out the latest change in the offset in
timestamps of the previous request and response, which were captured
before the change actually happened.
Report the number of received interleaved requests and current timestamp
count with their span.
Expand the serverstats description in chronyc man page.
Use the new cmdparse function for parsing the (cmd)allow/deny commands
and refactor the code a bit to reduce the number of functions needed for
all the (cmd)allow/deny(all) combinations.
When separate client and server instances of chronyd are running on one
computer (e.g. for security or performance reasons) and are synchronized
to each other, the server instance provides a reference ID based on the
local address used for synchronization of its NTP clock, which breaks
detection of synchronization loops for its own clients.
Add a "copy" option to specify that the server and client are closely
related, no loop can form between them, and the client should assume the
reference ID and stratum of the server to fix detection of loops between
the server and clients of the client.
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.
