From 6f725e53bc2c06704082fdc0f2141185237fb3df Mon Sep 17 00:00:00 2001
From: Roman Bazalevsky <rvb@rvb.name>
Date: Tue, 8 Sep 2015 15:58:57 +0300
Subject: [PATCH 1/1] Release

---
 ddns      | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 ddns.conf | 24 +++++++++++++++++
 2 files changed, 104 insertions(+)
 create mode 100755 ddns
 create mode 100644 ddns.conf

diff --git a/ddns b/ddns
new file mode 100755
index 0000000..b3f6736
--- /dev/null
+++ b/ddns
@@ -0,0 +1,80 @@
+#!/bin/bash
+
+. /etc/ddns/ddns.conf
+
+IFS=, HOSTS=($HOSTNAME)
+MAINHOST=$HOSTS
+
+if [ -z "$SLEEP" ] ; then
+  $SLEEP=60
+fi
+
+while :
+
+do
+
+echo "Sleeping..."
+sleep $SLEEP
+
+new_ip_address=$(curl -4 $URL | sed 's/[ \t\n]*$//')
+
+result=$(whois $new_ip_address)
+
+if [ $? = 0 ]
+then
+
+# Ignoring, if after mobile NAT
+cnt=`echo "$result" | grep descr | grep -i 'beeline\|mts\|megafon' | wc -l`
+
+if [ $cnt -gt 0 ]
+then
+  echo "Mobile NAT detected, backup channel, no action taken"
+  continue
+fi
+
+if [ -z "$new_ip_address" ] ; then
+  echo "New IP unknown"
+  continue
+fi  
+
+if [ -z "$old_ip_address" ] ; then
+  old_ip_address=$(host -W 1 -R 4 -4 -t A $MAINHOST $SERVER | grep "has address" | awk '{print $4}')
+  old_ip_address=$(echo $old_ip_address)
+  if [ -z "$old_ip_address" ] ; then
+    echo "Old IP unknown"
+    continue
+  fi
+fi  
+
+echo "[$old_ip_address],[$new_ip_address]"
+
+if [ "$old_ip_address" = "$new_ip_address" ] ; then
+
+  echo "IP not changed, no action"
+
+else
+
+  for host in ${HOSTS[@]}; do
+    nsupdate -v -k $KEYFILE << EOF
+server $SERVER
+zone $ZONE
+update delete $host A
+update add $host $TTL A $new_ip_address
+send
+EOF
+
+    echo "DNS update for $host"
+  done  
+  
+  unset old_ip_address
+
+  if [ ! -z "$EXEC" ]
+  then
+    $EXEC
+  fi
+
+fi
+
+fi
+
+done
diff --git a/ddns.conf b/ddns.conf
new file mode 100644
index 0000000..fade014
--- /dev/null
+++ b/ddns.conf
@@ -0,0 +1,24 @@
+# URL, возвращающий IP-адрес клиента
+URL="http://my.server/ip.php"
+
+# TTL для записи в DNS
+TTL=120
+
+# DNS-сервер
+SERVER=my.server
+
+# Имена хостов, первый - "главный", по нему проверяется адрес
+HOSTNAME=my.host.,another.my.host.,yet-another.my.host.
+
+# Зона DNS
+ZONE=my.host
+
+# Ключ для nsupdate
+KEYFILE=/etc/ddns/my.host.private
+
+# Пауза между обновлениями
+SLEEP=30
+
+# Скрипты, вызываемый при обнаружении смены адресов (рестарт сервисов и т.п.)
+EXEC=/usr/local/bin/restart-ip
+
-- 
2.34.1