From a892c5946a07cb8f94ce1c39918859c37cfaeb21 Mon Sep 17 00:00:00 2001
From: Michael Tremer <michael.tremer@ipfire.org>
Date: Mon, 7 Jul 2014 18:25:14 +0000
Subject: [PATCH] Add support for the BIND nsupdate utility

---
 ddns.conf.sample      |  9 ++++++
 src/ddns/providers.py | 67 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+)

diff --git a/ddns.conf.sample b/ddns.conf.sample
index 29b1ef1..3dd54c9 100644
--- a/ddns.conf.sample
+++ b/ddns.conf.sample
@@ -20,6 +20,15 @@
 # username = user
 # password = pass
 
+# [test.bind.nsupdate]
+# provider = nsupdate
+#
+# (optional)
+# server = 1.2.3.4
+# key = name
+# secret = XYZ
+# ttl = 60
+
 # [test.dhs.org]
 # provider = dhs.org
 # username = user
diff --git a/src/ddns/providers.py b/src/ddns/providers.py
index ed893a4..bc16c4c 100644
--- a/src/ddns/providers.py
+++ b/src/ddns/providers.py
@@ -20,6 +20,7 @@
 ###############################################################################
 
 import logging
+import subprocess
 import urllib2
 import xml.dom.minidom
 
@@ -253,6 +254,72 @@ class DDNSProviderAllInkl(DDNSProvider):
 		raise DDNSUpdateError
 
 
+class DDNSProviderBindNsupdate(DDNSProvider):
+	handle  = "nsupdate"
+	name    = "BIND nsupdate utility"
+	website = "http://en.wikipedia.org/wiki/Nsupdate"
+
+	DEFAULT_TTL = 60
+
+	def update(self):
+		scriptlet = self.__make_scriptlet()
+
+		# -v enables TCP hence we transfer keys and other data that may
+		# exceed the size of one packet.
+		# -t sets the timeout
+		command = ["nsupdate", "-v", "-t", "60"]
+
+		p = subprocess.Popen(command, shell=True,
+			stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+		)
+		stdout, stderr = p.communicate(scriptlet)
+
+		if p.returncode == 0:
+			return
+
+		raise DDNSError("nsupdate terminated with error code: %s\n  %s" % (p.returncode, stderr))
+
+	def __make_scriptlet(self):
+		scriptlet = []
+
+		# Set a different server the update is sent to.
+		server = self.get("server", None)
+		if server:
+			scriptlet.append("server %s" % server)
+
+		key = self.get("key", None)
+		if key:
+			secret = self.get("secret")
+
+			scriptlet.append("key %s %s" % (key, secret))
+
+		ttl = self.get("ttl", self.DEFAULT_TTL)
+
+		# Perform an update for each supported protocol.
+		for rrtype, proto in (("AAAA", "ipv6"), ("A", "ipv4")):
+			address = self.get_address(proto)
+			if not address:
+				continue
+
+			scriptlet.append("update delete %s. %s" % (self.hostname, rrtype))
+			scriptlet.append("update add %s. %s %s %s" % \
+				(self.hostname, ttl, rrtype, address))
+
+		# Send the actions to the server.
+		scriptlet.append("send")
+		scriptlet.append("quit")
+
+		logger.debug(_("Scriptlet:"))
+		for line in scriptlet:
+			# Masquerade the line with the secret key.
+			if line.startswith("key"):
+				line = "key **** ****"
+
+			logger.debug("  %s" % line)
+
+		return "\n".join(scriptlet)
+
+
 class DDNSProviderDHS(DDNSProvider):
 	handle    = "dhs.org"
 	name      = "DHS International"
-- 
2.39.2