mdw@git.distorted.org.uk Git - userv-utils/blob - dyndns/update

   1 #!/bin/bash
   2
   3 # Copyright 1996-2013 Ian Jackson <ijackson@chiark.greenend.org.uk>
   4 # Copyright 1998 David Damerell <damerell@chiark.greenend.org.uk>
   5 # Copyright 1999,2003
   6 #    Chancellor Masters and Scholars of the University of Cambridge
   7 # Copyright 2010 Tony Finch <fanf@dotat.at>
   8 #
   9 # This is free software; you can redistribute it and/or modify it
  10 # under the terms of the GNU General Public License as published by
  11 # the Free Software Foundation; either version 3 of the License, or
  12 # (at your option) any later version.
  13 #
  14 # This program is distributed in the hope that it will be useful, but
  15 # WITHOUT ANY WARRANTY; without even the implied warranty of
  16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 # General Public License for more details.
  18 #
  19 # You should have received a copy of the GNU General Public License
  20 # along with userv-utils; if not, see http://www.gnu.org/licenses/.
  21
  22 set -e
  23
  24 zone="$1"
  25 subdomain="$2"
  26 interval_min="$3"
  27 interval_avg="$4"
  28 interval_mem="$5"
  29
  30 now=`date +%s`
  31 charge=0
  32
  33 case $subdomain in
  34 '@')    files=_                 ;;
  35 *)      files=$subdomain        ;;
  36 esac
  37
  38 if test -f $files,timings && read lastup charge <$files,timings
  39 then
  40         if [ $now -lt $[ $lastup + $interval_min ] ]; then
  41                 echo "wait $[ $lastup + $interval_min - $now ]"
  42                 echo >&2 "must wait at least $interval_min between updates"
  43                 exit 75
  44         fi
  45         charge=$[ $charge + $interval_avg - ($now - $lastup) ]
  46         if [ $charge -gt $interval_mem ]; then
  47                 echo "wait $[ $charge - $interval_mem ]"
  48                 echo >&2 "must wait on average $interval_avg between updates"
  49                 exit 75
  50         fi
  51         if [ $charge -lt 0 ]; then charge=0; fi
  52 fi
  53
  54 sort >$files,new
  55
  56 if test -f $files,data
  57 then
  58         set +e
  59         diff >/dev/null $files,data $files,new
  60         diff=$?
  61         set -e
  62
  63         if [ $diff = 0 ]; then echo 'unchanged'; exit 0; fi
  64         if [ $diff != 1 ]; then exit 1; fi
  65 fi
  66
  67 echo $now $charge >$files,timings.new
  68 mv -f $files,timings.new $files,timings
  69 mv $files,new $files,data
  70
  71 exec /usr/share/userv/dyndns/install $zone