diff options
Diffstat (limited to 'dns/resolver.py')
| -rw-r--r-- | dns/resolver.py | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/dns/resolver.py b/dns/resolver.py index c6214ca..9f9b438 100644 --- a/dns/resolver.py +++ b/dns/resolver.py @@ -23,6 +23,7 @@ import sys import time import dns.exception +import dns.flags import dns.ipv4 import dns.ipv6 import dns.message @@ -772,6 +773,13 @@ class Resolver(object): response = dns.query.udp(request, nameserver, timeout, self.port, source=source) + if response.flags & dns.flags.TC: + # Response truncated; retry with TCP. + timeout = self._compute_timeout(start) + response = dns.query.tcp(request, nameserver, + timeout, self.port, + source=source) + except (socket.error, dns.exception.Timeout): # # Communication failure or timeout. Go to the @@ -794,6 +802,16 @@ class Resolver(object): nameservers.remove(nameserver) response = None continue + except EOFError: + # + # We're using TCP and they hung up on us. + # Probably they don't support TCP (though + # they're supposed to!). Take it out of the + # mix and continue. + # + nameservers.remove(nameserver) + response = None + continue rcode = response.rcode() if rcode == dns.rcode.NOERROR or \ rcode == dns.rcode.NXDOMAIN: |