Before enabling NTS, check for more gnutls functions (some added in
3.6.3) to avoid build failures with older gnutls versions. Also, make
sure that nettle supports the new AES interface (added in 3.0).
Move most of the authentication-specific code to a new file and
introduce authenticator instances in order to support other
authentication mechanisms (e.g. NTS).
Real-time scheduling and memory locking is available on posix compliant
OSs. This patch centralizes this functionality and brings support to
FreeBSD, NetBSD, and Solaris.
[ML: updated coding style]
Fix an issue with Linux and musl libc where sched_setscheduler is not
implemented. It seems that pthread_setschedparam is more widely
supported across different C libraries and OSs. For our use case, it
should make no difference which call is used.
The current code uses macros from inttypes.h. There is no point in
detecting and selecting between stdint.h and inttypes.h as the latter is
always needed.
This allows chronyd to remove its pidfile on exit after dropping the
root privileges in order to prevent another chronyd instance from
failing to start, e.g. due to a wrong SELinux label from chronyd -q.
Use nettle_hashes[] instead of nettle_get_hashes(), which is available
only in nettle >= 3.4. nettle_hashes[] is a symbol available in older
versions and may be renamed in future. In nettle >= 3.4 it is a macro
using nettle_get_hashes() for compatibility.
The socket.h header provided by musl doesn't seem to include the kernel
headers and is missing SCM_TIMESTAMPING_PKTINFO, which causes the
Linux-specific code in chrony to fail to build.
If no CFLAGS are specified, check if common security hardening options
are supported and add them to the CFLAGS/LDFLAGS. These are typically
enabled in downstream packages, but users compiling chrony from sources
with default CFLAGS should get hardened binaries too.
macOS 10.13 will implement the ntp_adjtime() system call, allowing
better control over the system clock than is possible with the existing
adjtime() system call. chronyd will support both the older and newer
calls, enabling binary code to run without recompilation on macOS 10.9
through macOS 10.13.
Early releases of macOS 10.13 have a very buggy adjtime() call. The
macOS driver tests adjtime() to see if the bug has been fixed. If the
bug persists then the timex driver is invoked otherwise the netbsd
driver.
New timestamping options may be available in kernel 4.13. They can be
used to get the index of the interface which timestamped incoming packet
together with its length at layer 2, enable simultaneous SW and HW TX
timestamping, and enable a new RX filter for NTP packets.
Move the res_init() call from do_name_to_ipaddress() into a separate
privops operation. Use it in ntp_sources and avoid unnecessary
res_init() calls in the main thread.
Add a new directive to specify interfaces which should be used for HW
timestamping. Extend the Linux ntp_io initialization to enable HW
timestamping, configure the RX filter using the SIOCSHWTSTAMP ioctl,
open their PHC devices, and track them as hwclock instances. When
messages with HW timestamps are received, use the PTP_SYS_OFFSET ioctl
to make PHC samples for hwclock.
Enable SCM_TIMESTAMPING control messages and the socket's error queue in
order to receive our transmitted packets with a more accurate transmit
timestamp. Add a new file for Linux-specific NTP I/O and implement
processing of these messages there.
