Handle HTTP error 404 generically

[ddns.git] / src / ddns / system.py

diff --git a/src/ddns/system.py b/src/ddns/system.py
index b086f5e9fabed988e99b119732f86f9543935903..8415579455763369a0a9ac844841ab2ee1f39945 100644 (file)
--- a/src/ddns/system.py
+++ b/src/ddns/system.py
@@ -64,11 +64,9 @@ class DDNSSystem(object):
 
                return proxy
 
-       def get_local_ipv6_address(self):
-               return # XXX TODO
-
-       def get_local_ipv4_address(self):
-               if self.distro == "ipfire-2":
+       def get_local_ip_address(self, proto):
+               # Legacy code for IPFire 2.
+               if self.distro == "ipfire-2" and proto == "ipv4":
                        try:
                                with open("/var/ipfire/red/local-ipaddress") as f:
                                        return f.readline()
@@ -80,7 +78,8 @@ class DDNSSystem(object):
 
                                raise
 
-               return # XXX TODO
+               # XXX TODO
+               raise NotImplementedError
 
        def _guess_external_ip_address(self, url, timeout=10):
                """
@@ -167,6 +166,11 @@ class DDNSSystem(object):
                        return resp
 
                except urllib2.HTTPError, e:
+                       # Log response header.
+                       logger.debug(_("Response header (Status Code %s):") % e.code)
+                       for k, v in e.hdrs.items():
+                               logger.debug("  %s: %s" % (k, v))
+
                        # 400 - Bad request
                        if e.code == 400:
                                raise DDNSRequestError(e.reason)
@@ -176,6 +180,12 @@ class DDNSSystem(object):
                        elif e.code in (401, 403):
                                raise DDNSAuthenticationError(e.reason)
 
+                       # 404 - Not found
+                       # Either the provider has changed the API, or
+                       # there is an error on the server
+                       elif e.code == 404:
+                               raise DDNSNotFound(e.reason)
+
                        # 500 - Internal Server Error
                        elif e.code == 500:
                                raise DDNSInternalServerError(e.reason)
@@ -189,9 +199,15 @@ class DDNSSystem(object):
 
                except urllib2.URLError, e:
                        if e.reason:
+                               # Name or service not known
+                               if e.reason.errno == -2:
+                                       raise DDNSResolveError
+
                                # Network Unreachable (e.g. no IPv6 access)
                                if e.reason.errno == 101:
                                        raise DDNSNetworkUnreachableError
+
+                               # Connection Refused
                                elif e.reason.errno == 111:
                                        raise DDNSConnectionRefusedError
 
@@ -248,18 +264,52 @@ class DDNSSystem(object):
                # Check if the external IP address should be guessed from
                # a remote server.
                guess_ip = self.core.settings.get("guess_external_ip", "true")
+               guess_ip = guess_ip in ("true", "yes", "1")
 
-               # If the external IP address should be used, we just do
-               # that.
-               if guess_ip in ("true", "yes", "1"):
+               # If the external IP address should be used, we just do that.
+               if guess_ip:
                        return self.guess_external_ip_address(proto)
 
-               # Get the local IP addresses.
-               else:
-                       if proto == "ipv6":
-                               return self.get_local_ipv6_address()
-                       elif proto == "ipv4":
-                               return self.get_local_ipv4_address()
+               # Get the local IP address.
+               local_ip_address = self.get_local_ip_address(proto)
+
+               # If the local IP address is not usable, we must guess
+               # the correct IP address...
+               if not self._is_usable_ip_address(proto, local_ip_address):
+                       local_ip_address = self.guess_external_ip_address(proto)
+
+               return local_ip_address
+
+       def _is_usable_ip_address(self, proto, address):
+               """
+                       Returns True is the local IP address is usable
+                       for dynamic DNS (i.e. is not a RFC1918 address or similar).
+               """
+               if proto == "ipv4":
+                       # This is not the most perfect solution to match
+                       # these addresses, but instead of pulling in an entire
+                       # library to handle the IP addresses better, we match
+                       # with regular expressions instead.
+                       matches = (
+                               # RFC1918 address space
+                               r"^10\.\d+\.\d+\.\d+$",
+                               r"^192\.168\.\d+\.\d+$",
+                               r"^172\.(1[6-9]|2[0-9]|31)\.\d+\.\d+$",
+
+                               # Dual Stack Lite address space
+                               r"^100\.(6[4-9]|[7-9][0-9]|1[01][0-9]|12[0-7])\.\d+\.\d+$",
+                       )
+
+                       for match in matches:
+                               m = re.match(match, address)
+                               if m is None:
+                                       continue
+
+                               # Found a match. IP address is not usable.
+                               return False
+
+               # In all other cases, return OK.
+               return True
 
        def resolve(self, hostname, proto=None):
                addresses = []
@@ -281,6 +331,10 @@ class DDNSSystem(object):
                        if e.errno == -2:
                                return []
 
+                       # Temporary failure in name resolution
+                       elif e.errno == -3:
+                               raise DDNSResolveError(hostname)
+
                        # No record for requested family available (e.g. no AAAA)
                        elif e.errno == -5:
                                return []