Add a simple call to resolve a hostname.

diff --git a/src/ddns/system.py b/src/ddns/system.py
index 8fa5c42e7dbdd0fc8ed6b99136dffde2d57ddc83..a071e489f1e5850367e150eb52135a8002770ef3 100644 (file)
--- a/src/ddns/system.py
+++ b/src/ddns/system.py
@@ -21,6 +21,7 @@
 
 import base64
 import re
+import socket
 import urllib
 import urllib2
 
@@ -179,3 +180,42 @@ class DDNSSystem(object):
 
                # XXX TODO
                assert False
+
+       def resolve(self, hostname, proto=None):
+               addresses = []
+
+               if proto is None:
+                       family = 0
+               elif proto == "ipv6":
+                       family = socket.AF_INET6
+               elif proto == "ipv4":
+                       family = socket.AF_INET
+               else:
+                       raise ValueError("Protocol not supported: %s" % proto)
+
+               # Resolve the host address.
+               response = socket.getaddrinfo(hostname, None, family)
+
+               # Handle responses.
+               for family, socktype, proto, canonname, sockaddr in response:
+                       # IPv6
+                       if family == socket.AF_INET6:
+                               address, port, flow_info, scope_id = sockaddr
+
+                               # Only use the global scope.
+                               if not scope_id == 0:
+                                       continue
+
+                       # IPv4
+                       elif family == socket.AF_INET:
+                               address, port = sockaddr
+
+                       # Ignore everything else...
+                       else:
+                               continue
+
+                       # Add to repsonse list if not already in there.
+                       if not address in addresses:
+                               addresses.append(address)
+
+               return addresses