= TO DO =

=== Testing ===

* We need to live-test various refclocks.  It would be nice
  to test the full matrix of refclock x platform, but that's too
  much work.  We should probably test as many refclocks as we can
  on at least one platform and test the NMEA, PPS, and SHM drivers
  on most platforms.

=== Slow convergence ===

[quote, Gary Miller]
__________
ntpd takes way, way, way longer to converge than chronyd.  Which is
why on the fly reconfiguration in ntpd is SO important.  Last thing you
ever want to do is restart ntpd.

Right now, after 10 mins, ntpd has 2,000 times the jitter as chronyd had
when I turned it off.
__________

Also see https://gitlab.com/NTPsec/ntpsec/issues/68 where the dubiousness
of the current startup logic gets discussed.

=== SHM ===

* Split out the low level code so it can be used by other drivers
  and a monitor program.

* Fix the code so that the read side is read-only.  This allows
  multiple readers and cleans up the file access mess.


=== Future plans ===

* Implement Google's proposed standard smear?
  See https://developers.google.com/time/smear

* Add .tar.xz tarball.

* Fix ntpq retransmissions.
  Too many cases don't work well enough (may be inherited from ntp classic).

* Test that the pool code properly replaces a server if it goes dark. (Not
  clear how to arrange this.)

* We could open only IPv6 sockets and allow them to handle mapped IPv4 addresses,
  as described at http://man7.org/linux/man-pages/man7/ipv6.7.html

* A clock driver or auxiliary daemon for PTP.

* Hal says "We need a way to inspect/debug bits on the wire. `ntpdate
  -du' is the traditional approach."  Hal's straw man is a new program
  rather than trying to make ntpdig do this.  Eric's proposed answer:
  ntpshark, a command interpreter written around the ntp Python module
  (or scapy) and loosely modeled on wireshark.

* Measure time from the clock reading to transmission for outbound
  packets.  Use the measurement to correct for computation time
  before transmission.  This is more interesting for authenticated packets.

* We might be able to eliminate a lot of the Linux runtime
  droproot code by using file capabilities.

* Use the snprintb in ntptime/ntptime.c for flag words like flash
  codes and use it systematically to make reports more readable.

* Timer events need, as much as possible, to be eliminated - they eat
  power on laptops and mobile devices, usually unnecessarily. To fix this,
  go to an event-queue architecture that wakes the daemon up just in time
  for the next scheduled event (rather than a once-per-second timer tick).

Plug restrict holes:
  The current code pokes a hole in any restrictions to let servers
  through if they come from DNS lookups.  We should add something like
  a nohole flag to prevent this so you can really block pool servers if
  you know there are some you don't want to use.

Solaris maintenance mode
  There is code in ntp_proto.c that drops into Solaris maintenance mode
  if the clock offset exceeds the panic threshold.  We should either
  drop that code or move it to where it can be used on all fatal errors.
  (Search for HAVE_LIBSCF_H)

Remove clock fuzzing:
  ntpd has code to fuzz the clocks.  It's scattered all over the place.
  That made sense when clocks were updated in big steps on a scheduler
  interrupt.  But most modern OSes use something like Intel's TSC to
  implement fine grained clocks.  We should review this area to verify
  that fuzzing is still useful.

SIGHUP should do more:
  reload keys file (easy, it already reloads the leap file)
  reload ntp.conf (hard, but needed to add new keys,
    we could kludge a partial reload to add/delete servers)

Waf detect need configure:
  There are problems with people forgetting to run configure or clean
  after a git pull.  (From email on 23 May 2017)

Version string cleanup:
  The version string should change if I make an edit and rebuild
    currently it only changes when something in git changes
  We need to be sure not to break the stable checksum feature.

Pivot cleanup:
  Currently, ntpd does a pivot deep in step_systime in libntp/systime.c
  That handles the problem of 32 bits of seconds wrapping in 2038.
  Posix is shifting to a 64 bit time_t, but we only have 32 bits
  of seconds in l_fp.  We can clean up a lot of code if l_fp is
  only used for offsets except when used in packets.  That requires
  pushing the pivot logic down close to the packet processing.

  There may be interactions with ntpq.

Recvbuff cleanup:
  ntpd currently has a pool of recv buffers.  That made sense
  when it was using SIGIO to get time stamps.  Now it is useless
  and just adds useless cycles moving things to/from the free list.

[quote, Hal]
__________
I think there is some interaction between when the ACTS driver calls and the
state of other stuff, like the connection to the net.  This is probably a
good candidate to get cleaned up.

There is another possible tangle in this area.  If you set "noselect" on the
server line in the config file, ntpd goes through all the action of
collecting the data and writing log files, but then drops the clock.  I don't
know things well enough to be sure that this sort of logic won't pick one
back up.
__________


== Old, sometime ancient stuff ==

970318: in hourly_stats(?), squawk if the magnitude of the drift is,
	say, >400.

== Simple tasks for an intern/trainee ==

* A conformant SNMP subagent in Python - see RFC 5907.

* In the docs subdirectory, include/command.adoc is an HTML passthrough
  in a not entirely successful attempt to emulate the look of the
  Mills HTML documentation this directory was made from. It should be
  cleaned up or replaced.  Requires HTML and CSS skills; intern must
  be willing to learn asciidoc.

* Similarly, includes/footer.adoc is a tabular hack made to resemble
  the old HTML and should be cleaned up.  Requires HTML and CSS
  skills; intern must be willing to learn asciidoc

// end
