Handle trusted sources as a separate set of sources which is required to
have a majority for the selection to proceed. This should improve the
selection with multiple trusted sources (e.g. due to the auth selection
mode).
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.
Refactor the code to allow the selection options of the current sources
to be modified when other sources are added and removed. Also, make the
authentication status of each source available to the code which makes
the modifications.
Remove leap status from the NTP sample and set it independently from
the sample accumulation in order to accept a leap second sooner when
samples are filtered.
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.
If the minimum delay is known (in a static network configuration), it
can replace the measured minimum from the register. This should improve
the stability of corrections for asymmetric jitter, sample weighting and
maxdelay* tests.
If the -Q option is specified, disable by default pidfile, ntpport,
cmdport, Unix domain command socket, and clock control, in order to
allow starting chronyd without root privileges and/or when another
chronyd instance is already running.
Replace struct timeval with struct timespec as the main data type for
timestamps. This will allow the NTP code to work with timestamps in
nanosecond resolution.
