release/src/router/busybox/examples/var_service/ntpd/ntp.script

   1 #!/bin/sh
   2
   3 # Note that there is no provision to prevent several copies of the script
   4 # to be run in quick succession. In fact, it happens rather often
   5 # if initial syncronization results in a step.
   6 # You will see "step" and then "stratum" script runs, sometimes
   7 # as close as only 0.002 seconds apart.
   8 #
   9 # Script should be ready to deal with this.
  10
  11 dt=`date '+%Y-%m-%d %H:%M:%S'`
  12
  13 echo "`tail -n 199 -- "$0.log" 2>/dev/null`" >"$0.log.$$"
  14
  15 if test x"$1" = x"unsync" \
  16 ; then
  17         # No replies for our NTP requests were seen for some time.
  18         #
  19         # Among more mundate cases like network outages, this happens
  20         # if we ran for a LONG time (days) and ntp server's IP has changed.
  21         # ntpd has no code to re-resolve peers' addresses to IPs,
  22         # we need to help it:
  23         #
  24         echo "$dt: $1"\
  25                 "syncronization lost, restarting ntpd"\
  26                 >>"$0.log.$$"
  27         mv -- "$0.log.$$" "$0.log"
  28         kill $PPID
  29         exit
  30 fi
  31
  32 if test x"$stratum" != x"" \
  33 && test x"$poll_interval" != x"" \
  34 && test 4 -ge "$stratum" \
  35 && test 128 -le "$poll_interval" \
  36 ; then
  37         echo "$dt: $1"\
  38                 "freq_drift_ppm=$freq_drift_ppm"\
  39                 "offset=$offset"\
  40                 "stratum=$stratum"\
  41                 "poll_interval=$poll_interval,"\
  42                 "setting hardware clock"\
  43                 >>"$0.log.$$"
  44         mv -- "$0.log.$$" "$0.log"
  45         exec hwclock --systohc
  46 fi
  47
  48 echo "$dt: $1"\
  49         "freq_drift_ppm=$freq_drift_ppm"\
  50         "offset=$offset"\
  51         "stratum=$stratum"\
  52         "poll_interval=$poll_interval"\
  53         >>"$0.log.$$"
  54 mv -- "$0.log.$$" "$0.log"