Run getaddrinfo()/gethostbyname() in separate thread to avoid blocking.
Only one resolving thread is running at one time, so this should work
also on systems where the functions are not thread-safe.
Use the new asynchronous call to resolve addresses of NTP servers
configured by the server/peer directives. Introduce a callback to be
notified when the first resolving attempt ends to correctly finish
chronyd initialization (dumpfile reload and reference mode end).
This will be needed to prevent loading of dump files after sources have
already accumulated samples and possibly reference was already updated
when async resolving of sources is implemented.
When source is set as active, it's receiving reachability updates (e.g.
offline NTP sources are not active).
Also add function to count active sources.
Instead of giving up when a source has 7 reach updates, continue as long
as at least one source has fewer than 7 updates and can still have 3
samples to be selectable in that number of updates.
When no sources are responding, it will give up sooner.
With special reference update modes, the timeout handlers may add or
remove file descriptors from the read fd set, so it needs to be copied
for select() call after they are dispatched. Also, they can now request
quit, so the exit flag needs to be checked before select() to avoid
hanging.
If there are extra arguments on the chronyd command line, they will be
parsed as lines in a configuration file and the normal configuration file
will be ignored.
Explicitly set the number of iburst samples to the size of the register
to make sure there are at least 7 reachability updates and the
initstepslew mode can be ended.
The initstepslew code has its own minimal NTP implementation. Drop the
code, add a new initstepslew mode to the reference updating code and
use regular NTP sources with iburst flag for initstepslew addresses
instead. When an update is made or a source is found unreachable, log a
message, remove the initstepslew sources and switch to normal mode.
This reduces code duplication and makes initstepslew use features
implemented only in the main code like source combining or SO_TIMESTAMP
support.
Latest clknetsim now allows source and destination port numbers to
differ. This fixes the tests to work with the recent changes that added
client NTP sockets.
If acquisitionport is set to 0 (default), create and connect a new
socket for each server instead of using one socket per address family
for all servers.
Use separate sockets for NTP server or peer and client packets. The port
number is configured by the acquisitionport directive. With the default
value of 0 the port is assigned randomly by the kernel. It can be equal
to the value configured by the port directive to use the server sockets
for all packets as before.
