| 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 |