ntpclients/ntpwait.py

   1 #! @PYSHEBANG@
   2 # -*- coding: utf-8 -*-
   3 """\
   4 ntpwait - Wait for ntpd to stabilize the system clock.
   5 USAGE: ntpwait [-n tries] [-s sleeptime] [-v] [-h]
   6
   7     -n, --tries=num              Number of times to check ntpd
   8     -s, --sleep=num              How long to sleep between tries
   9     -v, --verbose                Be verbose
  10     -h, --help                   Issue help
  11     -V, --version                Output version information and exit
  12
  13 Options are specified by doubled hyphens and their name or by a single
  14 hyphen and the flag character.
  15
  16 A spurious 'not running' message can result from queries being disabled.
  17 """
  18
  19 # Copyright the NTPsec project contributors
  20 #
  21 # SPDX-License-Identifier: BSD-2-Clause
  22
  23 # Because we've actually seen this fail on a ^C during import of ntp.packet.
  24 import signal
  25 import sys
  26 signal.signal(signal.SIGINT, lambda signal, frame: sys.exit(2))
  27
  28 import getopt
  29 import re
  30 import time
  31 import socket
  32
  33 try:
  34     import ntp.magic
  35     import ntp.packet
  36     import ntp.util
  37 except ImportError as e:
  38     sys.stderr.write(
  39         "ntpwait: can't find Python NTP library.\n")
  40     sys.stderr.write("%s\n" % e)
  41     sys.exit(1)
  42
  43
  44 class Unbuffered(object):
  45     def __init__(self, stream):
  46         self.stream = stream
  47
  48     def write(self, data):
  49         self.stream.write(data)
  50         self.stream.flush()
  51
  52     def __getattr__(self, attr):
  53         return getattr(self.stream, attr)
  54
  55
  56 if __name__ == "__main__":
  57     bin_ver = "ntpsec-@NTPSEC_VERSION_EXTENDED@"
  58     ntp.util.stdversioncheck(bin_ver)
  59     try:
  60         (options, arguments) = getopt.getopt(sys.argv[1:], "hn:s:vV", [
  61             "tries=", "sleep=", "verbose", "help", "version"
  62         ])
  63     except getopt.GetoptError as err:
  64         sys.stderr.write(str(err) + "\n")
  65         raise SystemExit(2)
  66     tries = 100
  67     sleep = 6
  68     verbose = 0
  69     for (switch, val) in options:
  70         if switch in ("-n", "--tries"):
  71             errmsg = "Error: -n parameter '%s' not a number\n"
  72             tries = ntp.util.safeargcast(val, int, errmsg, __doc__)
  73         elif switch in ("-s", "--sleep"):
  74             errmsg = "Error: -s parameter '%s' not a number\n"
  75             sleep = ntp.util.safeargcast(val, int, errmsg, __doc__)
  76         elif switch in ("-v", "--verbose"):
  77             verbose += 1
  78         elif switch in ("-h", "--help"):
  79             sys.stdout.write(__doc__)
  80             raise SystemExit(0)
  81         elif switch in ("-V", "--version"):
  82             print("ntpwait %s" % ntp.util.stdversion())
  83             raise SystemExit(0)
  84
  85     # Autoflush stdout
  86     sys.stdout = Unbuffered(sys.stdout)
  87
  88     basetime = ntp.util.monoclock()
  89     if verbose:
  90         sys.stdout.write("Waiting for ntpd to synchronize...  ")
  91
  92     for i in range(1, tries):
  93         session = ntp.packet.ControlSession()
  94         # session.debug = 4
  95         if not session.openhost("localhost"):
  96             if verbose:
  97                 sys.stdout.write("\bntpd is not running!\n")
  98             continue
  99
 100         msg = None
 101         try:
 102             msg = session.doquery(2)     # Request system variables
 103         except ntp.packet.ControlException as e:
 104             sys.stderr.write("localhost: timed out, nothing received\n")
 105             sys.stderr.write(e.message)
 106         except socket.error:
 107             if verbose:
 108                 sys.stdout.write("\b" + "*+:."[i % 4])
 109             time.sleep(sleep)
 110             continue
 111
 112         if verbose >= 2:
 113             sys.stderr.write(repr(session.response) + "\n")
 114
 115         if msg and msg.startswith("***"):
 116             if verbose:
 117                 sys.stdout.write("\b" + msg + "\n")
 118             sys.exit(1)
 119
 120         m = re.search(r"leap=([^,]*),", repr(session.response))
 121         if m:
 122             leap = int(m.group(1))
 123         else:
 124             sys.stdout.write("\bLeap status not available\n")
 125             sys.exit(1)
 126
 127         if leap == ntp.magic.LEAP_NOTINSYNC:
 128             if verbose:
 129                 sys.stdout.write("\b" + "*+:."[i % 4])
 130             if i < tries:
 131                 time.sleep(sleep)
 132             continue
 133
 134         if leap in (ntp.magic.LEAP_NOWARNING, ntp.magic.LEAP_ADDSECOND,
 135                     ntp.magic.LEAP_DELSECOND):
 136             # We could check "sync" here to make sure we like the source...
 137             if verbose:
 138                 sys.stdout.write("\bOK! (%.1f seconds)\n" %
 139                                  (ntp.util.monoclock() - basetime))
 140             sys.exit(0)
 141
 142         sys.stdout.write("\bUnexpected 'leap' status <%s>\n" % leap)
 143         sys.exit(1)
 144
 145     if verbose:
 146         sys.stdout.write("\bNo!\nntpd did not synchronize.\n")
 147     sys.exit(1)
 148
 149 # end