Don't use dnspython for A and AAAA (but keep it for SRV).

dnspython don't perform a full resolv.
For example it don't manage /etc/hosts on linux.
This commit is contained in:
Guilhem Lettron 2013-12-09 15:44:35 +01:00
parent 540d6e9dbb
commit f4e3c04bbf

View File

@ -131,16 +131,16 @@ def resolve(host, port=None, service=None, proto='tcp',
results.append((host, '::1', port)) results.append((host, '::1', port))
results.append((host, '127.0.0.1', port)) results.append((host, '127.0.0.1', port))
if use_ipv6: if use_ipv6:
for address in get_AAAA(host, resolver=resolver): for address in get_AAAA(host):
results.append((host, address, port)) results.append((host, address, port))
for address in get_A(host, resolver=resolver): for address in get_A(host):
results.append((host, address, port)) results.append((host, address, port))
for host, address, port in results: for host, address, port in results:
yield host, address, port yield host, address, port
def get_A(host, resolver=None): def get_A(host):
"""Lookup DNS A records for a given host. """Lookup DNS A records for a given host.
If ``resolver`` is not provided, or is ``None``, then resolution will If ``resolver`` is not provided, or is ``None``, then resolution will
@ -158,32 +158,15 @@ def get_A(host, resolver=None):
# If not using dnspython, attempt lookup using the OS level # If not using dnspython, attempt lookup using the OS level
# getaddrinfo() method. # getaddrinfo() method.
if resolver is None:
try:
recs = socket.getaddrinfo(host, None, socket.AF_INET,
socket.SOCK_STREAM)
return [rec[4][0] for rec in recs]
except socket.gaierror:
log.debug("DNS: Error retreiving A address info for %s." % host)
return []
# Using dnspython:
try: try:
recs = resolver.query(host, dns.rdatatype.A) recs = socket.getaddrinfo(host, None, socket.AF_INET,
return [rec.to_text() for rec in recs] socket.SOCK_STREAM)
except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer): return [rec[4][0] for rec in recs]
log.debug("DNS: No A records for %s" % host) except socket.gaierror:
return [] log.debug("DNS: Error retreiving A address info for %s." % host)
except dns.exception.Timeout:
log.debug("DNS: A record resolution timed out for %s" % host)
return []
except dns.exception.DNSException as e:
log.debug("DNS: Error querying A records for %s" % host)
log.exception(e)
return [] return []
def get_AAAA(host):
def get_AAAA(host, resolver=None):
"""Lookup DNS AAAA records for a given host. """Lookup DNS AAAA records for a given host.
If ``resolver`` is not provided, or is ``None``, then resolution will If ``resolver`` is not provided, or is ``None``, then resolution will
@ -201,34 +184,17 @@ def get_AAAA(host, resolver=None):
# If not using dnspython, attempt lookup using the OS level # If not using dnspython, attempt lookup using the OS level
# getaddrinfo() method. # getaddrinfo() method.
if resolver is None: if not socket.has_ipv6:
if not socket.has_ipv6: log.debug("Unable to query %s for AAAA records: IPv6 is not supported", host)
log.debug("Unable to query %s for AAAA records: IPv6 is not supported", host) return []
return []
try:
recs = socket.getaddrinfo(host, None, socket.AF_INET6,
socket.SOCK_STREAM)
return [rec[4][0] for rec in recs]
except (OSError, socket.gaierror):
log.debug("DNS: Error retreiving AAAA address " + \
"info for %s." % host)
return []
# Using dnspython:
try: try:
recs = resolver.query(host, dns.rdatatype.AAAA) recs = socket.getaddrinfo(host, None, socket.AF_INET6,
return [rec.to_text() for rec in recs] socket.SOCK_STREAM)
except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer): return [rec[4][0] for rec in recs]
log.debug("DNS: No AAAA records for %s" % host) except (OSError, socket.gaierror):
log.debug("DNS: Error retreiving AAAA address " + \
"info for %s." % host)
return [] return []
except dns.exception.Timeout:
log.debug("DNS: AAAA record resolution timed out for %s" % host)
return []
except dns.exception.DNSException as e:
log.debug("DNS: Error querying AAAA records for %s" % host)
log.exception(e)
return []
def get_SRV(host, port, service, proto='tcp', resolver=None): def get_SRV(host, port, service, proto='tcp', resolver=None):
"""Perform SRV record resolution for a given host. """Perform SRV record resolution for a given host.