net/ddns-scripts/files/usr/lib/ddns/dynamic_dns_updater.sh

   1 #!/bin/sh
   2 # /usr/lib/dynamic_dns/dynamic_dns_updater.sh
   3 #
   4 # Written by Eric Paul Bishop, Janary 2008
   5 # Distributed under the terms of the GNU General Public License (GPL) version 2.0
   6 #
   7 # This script is (loosely) based on the one posted by exobyte in the forums here:
   8 # http://forum.openwrt.org/viewtopic.php?id=14040
   9 #
  10
  11 . /usr/lib/ddns/dynamic_dns_functions.sh
  12
  13
  14 service_id=$1
  15 if [ -z "$service_id" ]
  16 then
  17         echo "ERRROR: You must specify a service id (the section name in the /etc/config/ddns file) to initialize dynamic DNS."
  18         return 1
  19 fi
  20
  21 #default mode is verbose_mode, but easily turned off with second parameter
  22 verbose_mode="1"
  23 if [ -n "$2" ]
  24 then
  25         verbose_mode="$2"
  26 fi
  27
  28 ###############################################################
  29 # Leave this comment here, to clearly document variable names
  30 # that are expected/possible
  31 #
  32 # Now use load_all_config_options to load config
  33 # options, which is a much more flexible solution.
  34 #
  35 #
  36 #config_load "ddns"
  37 #
  38 #config_get enabled $service_id enabled
  39 #config_get service_name $service_id service_name
  40 #config_get update_url $service_id update_url
  41 #
  42 #
  43 #config_get username $service_id username
  44 #config_get password $service_id password
  45 #config_get domain $service_id domain
  46 #
  47 #
  48 #config_get use_https $service_id use_https
  49 #config_get cacert $service_id cacert
  50 #
  51 #config_get ip_source $service_id ip_source
  52 #config_get ip_interface $service_id ip_interface
  53 #config_get ip_network $service_id ip_network
  54 #config_get ip_url $service_id ip_url
  55 #
  56 #config_get force_interval $service_id force_interval
  57 #config_get force_unit $service_id force_unit
  58 #
  59 #config_get check_interval $service_id check_interval
  60 #config_get check_unit $service_id check_unit
  61 #########################################################
  62 load_all_config_options "ddns" "$service_id"
  63
  64
  65 #some defaults
  66 if [ -z "$check_interval" ]
  67 then
  68         check_interval=600
  69 fi
  70
  71 if [ -z "$retry_interval" ]
  72 then
  73         retry_interval=60
  74 fi
  75
  76 if [ -z "$check_unit" ]
  77 then
  78         check_unit="seconds"
  79 fi
  80
  81
  82 if [ -z "$force_interval" ]
  83 then
  84         force_interval=72
  85 fi
  86
  87 if [ -z "$force_unit" ]
  88 then
  89         force_unit="hours"
  90 fi
  91
  92 if [ -z "$use_https" ]
  93 then
  94         use_https=0
  95 fi
  96
  97
  98
  99 #some constants
 100
 101 if [ "x$use_https" = "x1" ]
 102 then
 103         retrieve_prog="/usr/bin/curl "
 104         if [ -f "$cacert" ]
 105         then
 106                 retrieve_prog="${retrieve_prog}--cacert $cacert "
 107         elif [ -d "$cacert" ]
 108         then
 109                 retrieve_prog="${retrieve_prog}--capath $cacert "
 110         fi
 111 else
 112         retrieve_prog="/usr/bin/wget -O - ";
 113 fi
 114
 115 service_file="/usr/lib/ddns/services"
 116
 117 ip_regex="[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}"
 118
 119 NEWLINE_IFS='
 120 '
 121
 122
 123 #determine what update url we're using if the service_name is supplied
 124 if [ -n "$service_name" ]
 125 then
 126         #remove any lines not containing data, and then make sure fields are enclosed in double quotes
 127         quoted_services=$(cat $service_file |  grep "^[\t ]*[^#]" |  awk ' gsub("\x27", "\"") { if ($1~/^[^\"]*$/) $1="\""$1"\"" }; { if ( $NF~/^[^\"]*$/) $NF="\""$NF"\""  }; { print $0 }' )
 128
 129
 130         #echo "quoted_services = $quoted_services"
 131         OLD_IFS=$IFS
 132         IFS=$NEWLINE_IFS
 133         for service_line in $quoted_services
 134         do
 135                 #grep out proper parts of data and use echo to remove quotes
 136                 next_name=$(echo $service_line | grep -o "^[\t ]*\"[^\"]*\"" | xargs -r -n1 echo)
 137                 next_url=$(echo $service_line | grep -o "\"[^\"]*\"[\t ]*$" | xargs -r -n1 echo)
 138
 139                 if [ "$next_name" = "$service_name" ]
 140                 then
 141                         update_url=$next_url
 142                 fi
 143         done
 144         IFS=$OLD_IFS
 145 fi
 146
 147 if [ "x$use_https" = x1 ]
 148 then
 149         update_url=$(echo $update_url | sed -e 's/^http:/https:/')
 150 fi
 151
 152
 153 verbose_echo "update_url=$update_url"
 154
 155
 156
 157 #if this service isn't enabled then quit
 158 if [ "$enabled" != "1" ]
 159 then
 160         return 0
 161 fi
 162
 163
 164
 165
 166
 167 #compute update interval in seconds
 168 case "$force_unit" in
 169         "days" )
 170                 force_interval_seconds=$(($force_interval*60*60*24))
 171                 ;;
 172         "hours" )
 173                 force_interval_seconds=$(($force_interval*60*60))
 174                 ;;
 175         "minutes" )
 176                 force_interval_seconds=$(($force_interval*60))
 177                 ;;
 178         "seconds" )
 179                 force_interval_seconds=$force_interval
 180                 ;;
 181         * )
 182                 #default is hours
 183                 force_interval_seconds=$(($force_interval*60*60))
 184                 ;;
 185 esac
 186
 187
 188
 189 #compute check interval in seconds
 190 case "$check_unit" in
 191         "days" )
 192                 check_interval_seconds=$(($check_interval*60*60*24))
 193                 ;;
 194         "hours" )
 195                 check_interval_seconds=$(($check_interval*60*60))
 196                 ;;
 197         "minutes" )
 198                 check_interval_seconds=$(($check_interval*60))
 199                 ;;
 200         "seconds" )
 201                 check_interval_seconds=$check_interval
 202                 ;;
 203         * )
 204                 #default is seconds
 205                 check_interval_seconds=$check_interval
 206                 ;;
 207 esac
 208
 209
 210
 211 #compute retry interval in seconds
 212 case "$retry_unit" in
 213         "days" )
 214                 retry_interval_seconds=$(($retry_interval*60*60*24))
 215                 ;;
 216         "hours" )
 217                 retry_interval_seconds=$(($retry_interval*60*60))
 218                 ;;
 219         "minutes" )
 220                 retry_interval_seconds=$(($retry_interval*60))
 221                 ;;
 222         "seconds" )
 223                 retry_interval_seconds=$retry_interval
 224                 ;;
 225         * )
 226                 #default is seconds
 227                 retry_interval_seconds=$retry_interval
 228                 ;;
 229 esac
 230
 231
 232
 233 verbose_echo "force seconds = $force_interval_seconds"
 234 verbose_echo "check seconds = $check_interval_seconds"
 235
 236 #kill old process if it exists & set new pid file
 237 if [ -d /var/run/dynamic_dns ]
 238 then
 239         #if process is already running, stop it
 240         if [ -e "/var/run/dynamic_dns/$service_id.pid" ]
 241         then
 242                 old_pid=$(cat /var/run/dynamic_dns/$service_id.pid)
 243                 test_match=$(ps | grep "^[\t ]*$old_pid")
 244                 verbose_echo "old process id (if it exists) = \"$test_match\""
 245                 if [ -n  "$test_match" ]
 246                 then
 247                         kill $old_pid
 248                 fi
 249         fi
 250
 251 else
 252         #make dir since it doesn't exist
 253         mkdir /var/run/dynamic_dns
 254 fi
 255 echo $$ > /var/run/dynamic_dns/$service_id.pid
 256
 257
 258
 259
 260 #determine when the last update was
 261 current_time=$(monotonic_time)
 262 last_update=$(( $current_time - (2*$force_interval_seconds) ))
 263 if [ -e "/var/run/dynamic_dns/$service_id.update" ]
 264 then
 265         last_update=$(cat /var/run/dynamic_dns/$service_id.update)
 266 fi
 267 time_since_update=$(($current_time - $last_update))
 268
 269
 270 human_time_since_update=$(( $time_since_update / ( 60 * 60 ) ))
 271 verbose_echo "time_since_update = $human_time_since_update hours"
 272
 273
 274
 275
 276 registered_ip=$(echo $(nslookup "$domain" 2>/dev/null) |  grep -o "Name:.*" | grep -o "$ip_regex")
 277
 278
 279 #do update and then loop endlessly, checking ip every check_interval and forcing an updating once every force_interval
 280
 281 while [ true ]
 282 do
 283         current_ip=$(get_current_ip)
 284
 285
 286         current_time=$(monotonic_time)
 287         time_since_update=$(($current_time - $last_update))
 288
 289
 290         verbose_echo "Running IP check..."
 291         verbose_echo "current system ip = $current_ip"
 292         verbose_echo "registered domain ip = $registered_ip"
 293
 294
 295         if [ "$current_ip" != "$registered_ip" ]  || [ $force_interval_seconds -lt $time_since_update ]
 296         then
 297                 verbose_echo "update necessary, performing update ..."
 298
 299                 #do replacement
 300                 final_url=$update_url
 301                 for option_var in $ALL_OPTION_VARIABLES
 302                 do
 303                         if [ "$option_var" != "update_url" ]
 304                         then
 305                                 replace_name=$(echo "\[$option_var\]" | tr 'a-z' 'A-Z')
 306                                 replace_value=$(eval echo "\$$option_var")
 307                                 replace_value=$(echo $replace_value | sed -f /usr/lib/ddns/url_escape.sed)
 308                                 final_url=$(echo $final_url | sed s^"$replace_name"^"$replace_value"^g )
 309                         fi
 310                 done
 311                 final_url=$(echo $final_url | sed s/"\[HTTPAUTH\]"/"$username${password:+:$password}"/g )
 312                 final_url=$(echo $final_url | sed s/"\[IP\]"/"$current_ip"/g )
 313
 314
 315                 verbose_echo "updating with url=\"$final_url\""
 316
 317                 #here we actually connect, and perform the update
 318                 update_output=$( $retrieve_prog "$final_url" )
 319                 if [ $? -gt 0 ]
 320                 then
 321                         verbose_echo "update failed"
 322                         sleep $retry_interval_seconds
 323                         continue
 324                 fi
 325
 326                 verbose_echo "Update Output:"
 327                 verbose_echo "$update_output"
 328                 verbose_echo ""
 329
 330                 #save the time of the update
 331                 current_time=$(monotonic_time)
 332                 last_update=$current_time
 333                 time_since_update='0'
 334                 registered_ip=$current_ip
 335
 336                 human_time=$(date)
 337                 verbose_echo "update complete, time is: $human_time"
 338
 339                 echo "$last_update" > "/var/run/dynamic_dns/$service_id.update"
 340         else
 341                 human_time=$(date)
 342                 human_time_since_update=$(( $time_since_update / ( 60 * 60 ) ))
 343                 verbose_echo "update unnecessary"
 344                 verbose_echo "time since last update = $human_time_since_update hours"
 345                 verbose_echo "the time is now $human_time"
 346         fi
 347
 348         #sleep for 10 minutes, then re-check ip && time since last update
 349         sleep $check_interval_seconds
 350 done
 351
 352 #should never get here since we're a daemon, but I'll throw it in anyway
 353 return 0
 354
 355
 356
 357