we now track blockip and only add when needed and only delete entries we created.

[toast/tdyndns.git] / bin / tdyndns_update

diff --git a/bin/tdyndns_update b/bin/tdyndns_update
index 3f46d136c0b5ee80033b9031ac27554850c6e44f..0667c87019e9c5346dd96ef8b733d158bf902441 100755 (executable)
--- a/bin/tdyndns_update
+++ b/bin/tdyndns_update
@@ -20,6 +20,19 @@ def ipfamily_by_ip(ip):
        assert False
 
 
+def forward_lookup(fqdn, ip_family):
+       """Returns the ip address of the fqdn or None if none is found..
+
+       :param fqdn: Fully qualified domain name.
+       :param ip_family: 'A' or 'AAAA'"""
+       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(ip_family):
+               if str(name)[:-1] == fqdn:  # [:-1] removes trailing dot
+                       return ipaddr.IPAddress(rdata.address)
+
+
 def reverse_lookup(ip):
        """Returns an iterator of fqdns for the given IP address.
 
@@ -59,16 +72,18 @@ 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']
-       check_call(command)
+       if ipfamily_by_ip(ip) == 'A':
+               command = ['iptables', '-I', 'blockip', '-s', str(ip), '-j', 'ACCEPT']
+               check_call(command)
 
 
 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']
-       check_call(command)
+       if ipfamily_by_ip(ip) == 'A':
+               command = ['iptables', '-D', 'blockip', '-s', str(ip), '-j', 'ACCEPT']
+               check_call(command)
 
 
 def main(args):
@@ -78,15 +93,21 @@ def main(args):
                                nsupdate_delete(args.fqdn, 'A')
                                nsupdate_delete(args.fqdn, 'AAAA')
                        else:
+                               ipfamily = ipfamily_by_ip(args.ip)
+                               sync_dynamic_zones()
+                               old_ip = forward_lookup(args.fqdn, ipfamily)
                                nsupdate_delete(args.fqdn, ipfamily_by_ip(args.ip))
-                               if ipfamily_by_ip(args.ip) == 'A':
-                                       sync_dynamic_zones()
-                                       if len(list(reverse_lookup(args.ip))) == 0:
-                                               blockip_whitelist_delete(args.ip)
+                               if old_ip is not None:
+                                       blockip_whitelist_delete(old_ip)
                else:
-                       nsupdate_delete(args.fqdn, ipfamily_by_ip(args.ip))
+                       ipfamily = ipfamily_by_ip(args.ip)
+                       sync_dynamic_zones()
+                       old_ip = forward_lookup(args.fqdn, ipfamily)
+                       nsupdate_delete(args.fqdn, ipfamily)
                        nsupdate_add(args.fqdn, args.ttl, args.ip)
-                       if ipfamily_by_ip(args.ip) == 'A':
+                       if old_ip != args.ip:
+                               if old_ip is not None:
+                                       blockip_whitelist_delete(old_ip)
                                blockip_whitelist_add(args.ip)
        except CalledProcessError as e:
                sys.exit(e.returncode)