Catch various network/server errors.

diff --git a/src/ddns/errors.py b/src/ddns/errors.py
index cd935d032001e65dfa25d08c82d2738f25fc9e59..f9cc3f627a7e88c7f5e8e14fc7d6256461c417ee 100644 (file)
--- a/src/ddns/errors.py
+++ b/src/ddns/errors.py
@@ -23,6 +23,10 @@ class DDNSError(Exception):
        pass
 
 
+class DDNSNetworkError(DDNSError):
+       pass
+
+
 class DDNSAbuseError(DDNSError):
        """
                Thrown when the server reports
@@ -56,6 +60,20 @@ class DDNSConfigurationError(DDNSError):
        pass
 
 
+class DDNSConnectionRefusedError(DDNSNetworkError):
+       """
+               Thrown when a connection is refused.
+       """
+       pass
+
+
+class DDNSConnectionTimeoutError(DDNSNetworkError):
+       """
+               Thrown when a connection to a server has timed out.
+       """
+       pass
+
+
 class DDNSHostNotFoundError(DDNSError):
        """
                Thrown when a configuration entry could
@@ -72,6 +90,13 @@ class DDNSInternalServerError(DDNSError):
        pass
 
 
+class DDNSNetworkUnreachableError(DDNSNetworkError):
+       """
+               Thrown when a network is not reachable.
+       """
+       pass
+
+
 class DDNSRequestError(DDNSError):
        """
                Thrown when a request could
@@ -80,6 +105,13 @@ class DDNSRequestError(DDNSError):
        pass
 
 
+class DDNSServiceUnavailableError(DDNSNetworkError):
+       """
+               Equivalent to HTTP error code 503.
+       """
+       pass
+
+
 class DDNSUpdateError(DDNSError):
        """
                Thrown when an update could not be

diff --git a/src/ddns/system.py b/src/ddns/system.py
index 90226b3943963771d070251fe7e9c0afefc4442b..59dc218868ae86467b43afc4a51d8a1d2bc23f1d 100644 (file)
--- a/src/ddns/system.py
+++ b/src/ddns/system.py
@@ -26,6 +26,7 @@ import urllib
 import urllib2
 
 from __version__ import CLIENT_VERSION
+from .errors import *
 from i18n import _
 
 # Initialize the logger.
@@ -61,7 +62,12 @@ class DDNSSystem(object):
                        Sends a request to an external web server
                        to determine the current default IP address.
                """
-               response = self.send_request("http://checkip6.dns.lightningwirelabs.com")
+               try:
+                       response = self.send_request("http://checkip6.dns.lightningwirelabs.com", timeout=10)
+
+               # If the server could not be reached, we will return nothing.
+               except DDNSNetworkError:
+                       return
 
                if not response.code == 200:
                        return
@@ -79,7 +85,12 @@ class DDNSSystem(object):
 
                        XXX does not work for IPv6.
                """
-               response = self.send_request("http://checkip4.dns.lightningwirelabs.com")
+               try:
+                       response = self.send_request("http://checkip4.dns.lightningwirelabs.com", timeout=10)
+
+               # If the server could not be reached, we will return nothing.
+               except DDNSNetworkError:
+                       return
 
                if response.code == 200:
                        match = re.search(r"Your IP address is: (\d+.\d+.\d+.\d+)", response.read())
@@ -129,7 +140,7 @@ class DDNSSystem(object):
                        logger.debug("  %s: %s" % (k, v))
 
                try:
-                       resp = urllib2.urlopen(req)
+                       resp = urllib2.urlopen(req, timeout=timeout)
 
                        # Log response header.
                        logger.debug(_("Response header:"))
@@ -139,9 +150,30 @@ class DDNSSystem(object):
                        # Return the entire response object.
                        return resp
 
+               except urllib2.HTTPError, e:
+                       # 503 - Service Unavailable
+                       if e.code == 503:
+                               raise DDNSServiceUnavailableError
+
+                       # Raise all other unhandled exceptions.
+                       raise
+
                except urllib2.URLError, e:
+                       if e.reason:
+                               # Network Unreachable (e.g. no IPv6 access)
+                               if e.reason.errno == 101:
+                                       raise DDNSNetworkUnreachableError
+                               elif e.reason.errno == 111:
+                                       raise DDNSConnectionRefusedError
+
+                       # Raise all other unhandled exceptions.
                        raise
 
+               except socket.timeout, e:
+                       logger.debug(_("Connection timeout"))
+
+                       raise DDNSConnectionTimeoutError
+
        def _format_query_args(self, data):
                args = []