Files
chrony/ntp_io_linux.c
Miroslav Lichvar 0df8328ceb ntp: keep kernel RX timestamping permanently enabled on Linux
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.
2018-02-16 11:09:54 +01:00

23 KiB