Silently fall back to the guess the IP address with a remote server

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

diff --git a/src/ddns/system.py b/src/ddns/system.py
index b086f5e9fabed988e99b119732f86f9543935903..c268ba5cbae57dbbdd3aa1e1023ab96ca0cf41b1 100644 (file)
--- a/src/ddns/system.py
+++ b/src/ddns/system.py
@@ -21,6 +21,7 @@
 
 import base64
 import re
+import ssl
 import socket
 import urllib
 import urllib2
@@ -64,11 +65,16 @@ class DDNSSystem(object):
 
                return proxy
 
-       def get_local_ipv6_address(self):
-               return # XXX TODO
+       def get_local_ip_address(self, proto):
+               ip_address = self._get_local_ip_address(proto)
 
-       def get_local_ipv4_address(self):
-               if self.distro == "ipfire-2":
+               # Check if the IP address is usable and only return it then
+               if self._is_usable_ip_address(proto, ip_address):
+                       return ip_address
+
+       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 +86,8 @@ class DDNSSystem(object):
 
                                raise
 
-               return # XXX TODO
+               # XXX TODO
+               raise NotImplementedError
 
        def _guess_external_ip_address(self, url, timeout=10):
                """
@@ -167,6 +174,11 @@ 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 +188,12 @@ 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)
@@ -189,12 +207,32 @@ class DDNSSystem(object):
 
                except urllib2.URLError, e:
                        if e.reason:
+                               # Handle SSL errors
+                               if isinstance(e.reason, ssl.SSLError):
+                                       e = e.reason
+
+                                       if e.reason == "CERTIFICATE_VERIFY_FAILED":
+                                               raise DDNSCertificateError
+
+                                       # Raise all other SSL errors
+                                       raise DDNSSSLError(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
 
+                               # No route to host
+                               elif e.reason.errno == 113:
+                                       raise DDNSNoRouteToHostError(req.host)
+
                        # Raise all other unhandled exceptions.
                        raise
 
@@ -248,18 +286,54 @@ 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"):
-                       return self.guess_external_ip_address(proto)
+               # Get the local IP address.
+               local_ip_address = None
 
-               # Get the local IP addresses.
-               else:
-                       if proto == "ipv6":
-                               return self.get_local_ipv6_address()
-                       elif proto == "ipv4":
-                               return self.get_local_ipv4_address()
+               if not guess_ip:
+                       try:
+                               local_ip_address = self.get_local_ip_address(proto)
+                       except NotImplementedError:
+                               logger.warning(_("Falling back to check the IP address with help of a public server"))
+
+               # If no local IP address could be determined, we will fall back to the guess
+               # it with help of an external server...
+               if not 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 +355,10 @@ 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 []