Add information about protocol, request, and response to NoNameservers exception.

Information about UDP/TCP protocol usage is returned from str(NoNameservers) but
request and response variables are intended for application debug logs
and are not returned from str().

str() for parametrized version of the exception now returns string like:
All nameservers failed to answer the query localhost. IN URI: Server 192.0.2.1 TCP port 53 anwered BADVERS; Server 192.0.2.2 UDP port 53 anwered BADVERS

diff --git a/dns/resolver.py b/dns/resolver.py
index e81caaf7602425977fff2ed732c79f7a74bf007e..443e1d06b644b1dae8d0656690be03840b083037 100644 (file)
--- a/dns/resolver.py
+++ b/dns/resolver.py
@@ -93,14 +93,15 @@ class NoNameservers(dns.exception.DNSException):
 
     msg = "All nameservers failed to answer the query."
     fmt = "%s {query}: {errors}" % msg[:-1]
-    supp_kwargs = set(['query', 'errors'])
+    supp_kwargs = set(['request', 'errors'])
 
     def _fmt_kwargs(self, **kwargs):
         srv_msgs = []
         for err in kwargs['errors']:
-            srv_msgs.append('Server %s anwered %s' % (err[0], err[1]))
-        return super(NoNameservers, self)._fmt_kwargs(query=kwargs['query'],
-                                                      errors='; '.join(srv_msgs))
+            srv_msgs.append('Server %s %s port %s anwered %s' % (err[0],
+                            'TCP' if err[1] else 'UDP', err[2], err[3]))
+        return super(NoNameservers, self)._fmt_kwargs(
+            query=kwargs['request'].question, errors='; '.join(srv_msgs))
 
 
 class NotAbsolute(dns.exception.DNSException):
@@ -849,10 +850,11 @@ class Resolver(object):
             backoff = 0.10
             while response is None:
                 if len(nameservers) == 0:
-                    raise NoNameservers(query=request.question, errors=errors)
+                    raise NoNameservers(request=request, errors=errors)
                 for nameserver in nameservers[:]:
                     timeout = self._compute_timeout(start)
                     try:
+                        tcp_attempt = tcp
                         if tcp:
                             response = dns.query.tcp(request, nameserver,
                                                      timeout, self.port,
@@ -865,6 +867,7 @@ class Resolver(object):
                                                      source_port=source_port)
                             if response.flags & dns.flags.TC:
                                 # Response truncated; retry with TCP.
+                                tcp_attempt = True
                                 timeout = self._compute_timeout(start)
                                 response = dns.query.tcp(request, nameserver,
                                                        timeout, self.port,
@@ -875,15 +878,17 @@ class Resolver(object):
                         # Communication failure or timeout.  Go to the
                         # next server
                         #
+                        errors.append((nameserver, tcp_attempt, self.port, ex,
+                                       response))
                         response = None
-                        errors.append((nameserver, ex))
                         continue
                     except dns.query.UnexpectedSource as ex:
                         #
                         # Who knows?  Keep going.
                         #
+                        errors.append((nameserver, tcp_attempt, self.port, ex,
+                                       response))
                         response = None
-                        errors.append((nameserver, ex))
                         continue
                     except dns.exception.FormError as ex:
                         #
@@ -892,8 +897,9 @@ class Resolver(object):
                         # continue.
                         #
                         nameservers.remove(nameserver)
+                        errors.append((nameserver, tcp_attempt, self.port, ex,
+                                       response))
                         response = None
-                        errors.append((nameserver, ex))
                         continue
                     except EOFError as ex:
                         #
@@ -903,13 +909,15 @@ class Resolver(object):
                         # mix and continue.
                         #
                         nameservers.remove(nameserver)
+                        errors.append((nameserver, tcp_attempt, self.port, ex,
+                                       response))
                         response = None
-                        errors.append((nameserver, ex))
                         continue
                     rcode = response.rcode()
                     if rcode == dns.rcode.YXDOMAIN:
                         ex = YXDOMAIN()
-                        errors.append((nameserver, ex))
+                        errors.append((nameserver, tcp_attempt, self.port, ex,
+                                       response))
                         raise ex
                     if rcode == dns.rcode.NOERROR or \
                            rcode == dns.rcode.NXDOMAIN:
@@ -921,7 +929,8 @@ class Resolver(object):
                     #
                     if rcode != dns.rcode.SERVFAIL or not self.retry_servfail:
                         nameservers.remove(nameserver)
-                    errors.append((nameserver, dns.rcode.to_text(rcode)))
+                    errors.append((nameserver, tcp_attempt, self.port,
+                                   dns.rcode.to_text(rcode), response))
                     response = None
                 if not response is None:
                     break