ssh-dyndns

   1 #!/bin/sh
   2 # dyndns via ssh login + tinydns (djbdns/dbndns)
   3 #
   4 # usage:
   5 # $ ssh dyndns@example.org home.example.org
   6 #
   7 # @author Christian Weiske <cweiske@cweiske.de>
   8
   9 if [ -z "$SSH_CONNECTION" ]; then
  10    echo "no ssh connection"
  11    exit 1
  12 fi
  13
  14 remoteip=${SSH_CLIENT%% *}
  15 if [ -z "$remoteip" ]; then
  16    echo "ssh client IP not found"
  17    exit 2
  18 fi
  19
  20 #TODO: support multiple domains
  21 if [ -z "$2" ]; then
  22     echo Missing argument: domain name
  23     exit 3
  24 fi
  25 domain="$2"
  26
  27 #load config files
  28 if [ -f ~/.config/ssh-dyndns.sh ]; then
  29     . ~/.config/ssh-dyndns.sh
  30 fi
  31 if [ -f /etc/ssh-dyndns.sh ]; then
  32     . /etc/ssh-dyndns.sh
  33 fi
  34
  35 if [ -z "$data_dir" ]; then
  36     echo '$data_dir not set'
  37     exit 4
  38 fi
  39 if [ ! -d "$data_dir" ]; then
  40     echo "$data_dir does not exist"
  41     exit 5
  42 fi
  43 if [ ! -f "$data_dir/Makefile" ]; then
  44     echo "$data_dir misses Makefile"
  45     exit 6
  46 fi
  47
  48 if [ ! -z "$domain_patterns" ]; then
  49     ok=0
  50     for single_dp in $domain_patterns; do
  51         case "$domain" in
  52             ($single_dp) ok=1;;
  53         esac
  54     done
  55     if [ $ok -ne 1 ]; then
  56         echo "Domain \"$domain\" does not match \$domain_pattern"
  57         exit 7
  58     fi
  59 fi
  60
  61
  62 file_pattern="${file_pattern:-data-dyndns-%DOMAIN%}"
  63 timeout=${timeout:-300}
  64
  65 datafile=${data_dir}`echo $file_pattern | sed "s/%DOMAIN%/$domain/"`
  66
  67 if [ `echo "$remoteip"| sed "s/://"` != "$remoteip" ]; then
  68     echo "IPv6 not supported yet"
  69     # we need ipv6 address expansion
  70     exit 8
  71 fi
  72
  73 #=cweiske.de:5.35.241.22
  74 djbdnsline="=${domain}:${remoteip}:${timeout}"
  75
  76 update=1
  77 if [ -f "$datafile" ]; then
  78     currentdata=`cat "$datafile"`
  79     if [ "$currentdata" = "$djbdnsline" ]; then
  80         #no need to update
  81         update=0
  82     fi
  83 fi
  84 if [ $update -eq 0 ]; then
  85     exit
  86 fi
  87
  88 echo $djbdnsline > $datafile
  89
  90 #compile dns data
  91 cd "$data_dir"
  92 make