X-Git-Url: https://git.toastfreeware.priv.at/toast/tdyndns.git/blobdiff_plain/8693ac19b712eeece371d48c4e2af3325386eb1b..50b28146b7c48d276d60710078cc779f17a1bce4:/bin/tdyndns_update

diff --git a/bin/tdyndns_update b/bin/tdyndns_update
index 45c4264..3f46d13 100755
--- a/bin/tdyndns_update
+++ b/bin/tdyndns_update
@@ -1,23 +1,15 @@
 #!/usr/bin/python
+import os
 import sys
 import re
 import argparse
-from subprocess import Popen, PIPE, call
+from subprocess import Popen, PIPE, check_call, CalledProcessError
 import ipaddr
+import dns.zone  # http://www.dnspython.org/
 
 
-class ExternalProgramError(RuntimeError):
-	pass
-
-
-class NsupdateError(ExternalProgramError):
-	def __init__(self, returncode):
-		self.returncode = returncode
-
-
-class BlockipError(ExternalProgramError):
-	def __init__(self, returncode):
-		self.returncode = returncode
+def sync_dynamic_zones():
+	check_call(['rndc', 'sync'])
 
 
 def ipfamily_by_ip(ip):
@@ -28,6 +20,18 @@ def ipfamily_by_ip(ip):
 	assert False
 
 
+def reverse_lookup(ip):
+	"""Returns an iterator of fqdns for the given IP address.
+
+	:param ip: Instance of ipaddr.IPv4Address or ipaddr.IPv6Address"""
+	filename = '/var/cache/bind/dyn.colgarra.priv.at'
+	zonename = os.path.basename(filename)
+	zone = dns.zone.from_file(filename, zonename, relativize=False)
+	for name, ttl, rdata in zone.iterate_rdatas(ipfamily_by_ip(ip)):
+		if ipaddr.IPAddress(rdata.address) == ip:
+			yield str(name)
+
+
 def nsupdate_add(fqdn, ttl, ip):
 	"""
 	:param fqdn: Fully qualified domain name
@@ -37,7 +41,7 @@ def nsupdate_add(fqdn, ttl, ip):
 	p = Popen(['nsupdate', '-l'], stdin=PIPE)
 	p.communicate(command)
 	if p.returncode != 0:
-		raise NsupdateError(p.returncode)
+		raise CalledProcessError(p.returncode, 'nsupdate -l')
 
 def nsupdate_delete(fqdn, ip_family):
 	"""
@@ -48,7 +52,7 @@ def nsupdate_delete(fqdn, ip_family):
 	p = Popen(['nsupdate', '-l'], stdin=PIPE)
 	p.communicate(command)
 	if p.returncode != 0:
-		raise NsupdateError(p.returncode)
+		raise CalledProcessError(p.returncode, 'nsupdate -l')
 
 
 def blockip_whitelist_add(ip):
@@ -56,9 +60,7 @@ def blockip_whitelist_add(ip):
 	:param ip: ipv4 address
 	:raises a BlockipError in case of errors."""
 	command = ['iptables', '-I', 'blockip', '-s', str(ip), '-j', 'ACCEPT']
-	p = call(command)
-	if p != 0:
-		raise BlockipError(p)
+	check_call(command)
 
 
 def blockip_whitelist_delete(ip):
@@ -66,9 +68,7 @@ def blockip_whitelist_delete(ip):
 	:param ip: ipv4 address
 	:raises a BlockipError in case of errors."""
 	command = ['iptables', '-D', 'blockip', '-s', str(ip), '-j', 'ACCEPT']
-	p = call(command)
-	if p != 0:
-		raise BlockipError(p)
+	check_call(command)
 
 
 def main(args):
@@ -80,13 +80,15 @@ def main(args):
 			else:
 				nsupdate_delete(args.fqdn, ipfamily_by_ip(args.ip))
 				if ipfamily_by_ip(args.ip) == 'A':
-					blockip_whitelist_delete(args.ip)
+					sync_dynamic_zones()
+					if len(list(reverse_lookup(args.ip))) == 0:
+						blockip_whitelist_delete(args.ip)
 		else:
 			nsupdate_delete(args.fqdn, ipfamily_by_ip(args.ip))
 			nsupdate_add(args.fqdn, args.ttl, args.ip)
 			if ipfamily_by_ip(args.ip) == 'A':
 				blockip_whitelist_add(args.ip)
-	except ExternalProgramError as e:
+	except CalledProcessError as e:
 		sys.exit(e.returncode)