From de9fee6eec828e95ff39469efc77a5121609c6bd Mon Sep 17 00:00:00 2001
From: Daniel Roethlisberger <daniel@roe.ch>
Date: Sun, 27 Apr 2014 20:03:38 +0200
Subject: [PATCH] Add nsupdate(1) support

The 'nsupdate' protocol is used to submit Dynamic DNS Update requests as
defined in RFC2136 to a name server using the 'nsupdate' command line
utility part of ISC BIND.  Dynamic DNS updates allow resource records to
be added or removed from a zone configured for dynamic updates through
DNS requests protected using TSIG.  BIND ships with 'ddns-confgen', a
utility to generate sample configurations and instructions for both the
server and the client.  See nsupdate(1) and ddns-confgen(8) for details.
---
 README.md |   1 +
 ddclient  | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 117 insertions(+)

diff --git a/README.md b/README.md
index a9a345c..d7eb970 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,7 @@ Dynamic DNS services currently supported include:
     Freedns     - See http://freedns.afraid.org/ for details
     ChangeIP    - See http://www.changeip.com/ for details
     dtdns       - See http://www.dtdns.com/ for details
+    nsupdate    - See nsupdate(1) and ddns-confgen(8) for details
 
 DDclient now supports many of cable/dsl broadband routers. 
 
diff --git a/ddclient b/ddclient
index 0acc8eb..1b9d3ef 100755
--- a/ddclient
+++ b/ddclient
@@ -429,6 +429,10 @@ my %variables = (
 	'login'               => setv(T_LOGIN,  0, 0, 0, 'unused',            undef),
 	'client'              => setv(T_STRING, 0, 1, 1, $program,            undef),
     },
+    'nsupdate-common-defaults' => {
+	'ttl'                 => setv(T_NUMBER, 0, 1, 0, 600,                 undef),
+	'zone'                => setv(T_STRING, 1, 1, 1, '',                  undef),
+    },
 );
 my %services = (
     'dyndns1' => {
@@ -573,6 +577,16 @@ my %services = (
 			  $variables{'service-common-defaults'},
 		        ),
     },
+    'nsupdate' => {
+	'updateable' => undef,
+	'update'     => \&nic_nsupdate_update,
+	'examples'   => \&nic_nsupdate_examples,
+	'variables'  => merge(
+			  { 'login'        => setv(T_LOGIN, 1, 0, 1, '/usr/bin/nsupdate', undef), },
+			  $variables{'nsupdate-common-defaults'},
+			  $variables{'service-common-defaults'},
+	),
+    },
 );
 $variables{'merged'} = merge($variables{'global-defaults'},
 			     $variables{'service-common-defaults'},
@@ -3765,6 +3779,108 @@ sub nic_dtdns_update {
     }
 }
 
+######################################################################
+## nic_nsupdate_examples
+######################################################################
+sub nic_nsupdate_examples {
+ return <<EoEXAMPLE;
+o 'nsupdate'
+
+The 'nsupdate' protocol is used to submit Dynamic DNS Update requests as
+defined in RFC2136 to a name server using the 'nsupdate' command line
+utility part of ISC BIND.  Dynamic DNS updates allow resource records to
+be added or removed from a zone configured for dynamic updates through
+DNS requests protected using TSIG.  BIND ships with 'ddns-confgen', a
+utility to generate sample configurations and instructions for both the
+server and the client.  See nsupdate(1) and ddns-confgen(8) for details.
+
+Configuration variables applicable to the 'nsupdate' protocol are:
+  protocol=nsupdate
+  server=ns1.example.com       ## name or IP address of the DNS server to send
+                               ## the update requests to; usually master for
+                               ## zone, but slaves should forward the request
+  password=tsig.key            ## path and name of the symmetric HMAC key file
+                               ## to use for TSIG signing of the request
+                               ## (as generated by 'ddns-confgen -q' and
+                               ## configured on server in 'grant' statement)
+  zone=dyn.example.com         ## forward zone that is to be updated
+  ttl=600                      ## time to live of the record;
+                               ## defaults to 600 seconds
+  login=/usr/bin/nsupdate      ## path and name of nsupdate binary;
+                               ## defaults to '/usr/bin/nsupdate'
+  <hostname>                   ## fully qualified hostname to update
+
+Example ${program}.conf file entries:
+  ## single host update
+  protocol=nsupdate \\
+  server=ns1.example.com \\
+  password=/etc/${program}/dyn.example.com.key \\
+  zone=dyn.example.com \\
+  ttl=3600 \\
+  myhost.dyn.example.com
+
+EoEXAMPLE
+}
+
+######################################################################
+## nic_nsupdate_update
+## by Daniel Roethlisberger <daniel@roe.ch>
+######################################################################
+sub nic_nsupdate_update {
+	debug("\nnic_nsupdate_update -------------------");
+
+	## group hosts with identical attributes together
+	my %groups = group_hosts_by([ @_ ], [ qw(login password server zone) ]);
+
+	## update each set of hosts that had similar configurations
+	foreach my $sig (keys %groups) {
+		my @hosts = @{$groups{$sig}};
+		my $hosts = join(',', @hosts);
+		my $h = $hosts[0];
+		my $binary = $config{$h}{'login'};
+		my $keyfile = $config{$h}{'password'};
+		my $server = $config{$h}{'server'};
+		my $zone = $config{$h}{'zone'};
+		my $ip = $config{$h}{'wantip'};
+		delete $config{$_}{'wantip'} foreach @hosts;
+
+		info("setting IP address to %s for %s", $ip, $hosts);
+		verbose("UPDATE:","updating %s", $hosts);
+
+		## send separate requests for each zone with all hosts in that zone
+		my $instructions = <<EoINSTR1;
+server $server
+zone $zone.
+EoINSTR1
+		foreach (@hosts) {
+			$instructions .= <<EoINSTR2;
+update delete $_.
+update add $_. $config{$_}{'ttl'} A $ip
+EoINSTR2
+		}
+		$instructions .= <<EoINSTR3;
+send
+EoINSTR3
+		my $command = "$binary -k $keyfile";
+		$command .= " -d" if (opt('debug'));
+		verbose("UPDATE:", "nsupdate command is: %s", $command);
+		verbose("UPDATE:", "nsupdate instructions are:\n%s", $instructions);
+
+		my $status = pipecmd($command, $instructions);
+		if ($status eq 1) {
+			foreach (@hosts) {
+				$config{$_}{'ip'} = $ip;
+				$config{$_}{'mtime'} = $now;
+				success("updating %s: %s: IP address set to %s", $_, $status, $ip);
+			}
+		} else {
+			foreach (@hosts) {
+				failed("updating %s", $_);
+			}
+		}
+	}
+}
+
 ######################################################################
 # vim: ai ts=4 sw=4 tw=78 :