def dns_query(input="", query_type="", server="", timeout=2.0):
"""A unified IPv4 & IPv6 DNS lookup interface; this is essentially just a wrapper around dnspython's API. When you query a PTR record, you can use an IPv4 or IPv6 address (which will automatically be converted into an in-addr.arpa name. This wrapper only supports a subset of DNS records: 'A', 'AAAA', 'CNAME', 'MX', 'NS', 'PTR', and 'TXT'
Kwargs:
- input (str): A string containing the DNS record to lookup
- query_type (str): A string containing the DNS record type (SOA not supported)
- server (str): A string containing the fqdn or IP address of the dns server
- timeout (float): DNS lookup timeout duration (default: 2.0 seconds)
Returns:
A set() of :class:`~ccp_util.DNSResponse` instances
>>> from ciscoconfparse.ccp_util import dns_query
>>> dns_query('www.pennington.net', 'A', '4.2.2.2')
set([<DNSResponse 'A' result_str='65.19.187.2'>])
>>> answer = dns_query('www.pennington.net', 'A', '4.2.2.2')
>>> str(answer.pop())
'65.19.187.2'
>>>
"""
valid_records = set(
['A', 'AAAA', 'AXFR', 'CNAME', 'MX', 'NS', 'PTR', 'TXT'])
query_type = query_type.upper()
assert query_type in valid_records
assert server != ""
assert float(timeout) > 0
assert input != ""
intput = input.strip()
retval = set([])
resolver = Resolver()
resolver.server = [socket.gethostbyname(server)]
resolver.timeout = float(timeout)
resolver.lifetime = float(timeout)
start = time.time()
if (query_type == "A") or (query_type == "AAAA"):
try:
answer = resolver.query(input, query_type)
duration = time.time() - start
for result in answer:
response = DNSResponse(query_type=query_type,
duration=duration,
input=input,
result_str=str(result.address))
retval.add(response)
except DNSException as e:
duration = time.time() - start
response = DNSResponse(input=input,
duration=duration,
query_type=query_type)
response.has_error = True
response.error_str = e
retval.add(response)
elif query_type == "AXFR":
"""This is a hack: return text of zone transfer, instead of axfr objs"""
_zone = zone.from_xfr(query.xfr(server, input, lifetime=timeout))
return [_zone[node].to_text(node) for node in _zone.nodes.keys()]
elif query_type == "CNAME":
try:
answer = resolver.query(input, query_type)
duration = time.time() - start
for result in answer:
response = DNSResponse(query_type=query_type,
duration=duration,
input=input,
result_str=str(result.target))
retval.add(response)
except DNSException as e:
duration = time.time() - start
response = DNSResponse(input=input,
duration=duration,
query_type=query_type)
response.has_error = True
response.error_str = e
retval.add(response)
elif query_type == "MX":
try:
answer = resolver.query(input, query_type)
duration = time.time() - start
for result in answer:
response = DNSResponse(query_type=query_type,
input=input,
result_str=str(result.target))
response.preference = int(result.preference)
retval.add(response)
except DNSException as e:
duration = time.time() - start
response = DNSResponse(input=input,
duration=duration,
query_type=query_type)
response.has_error = True
response.error_str = e
retval.add(response)
elif query_type == "NS":
try:
answer = resolver.query(input, query_type)
duration = time.time() - start
for result in answer:
response = DNSResponse(query_type=query_type,
duration=duration,
input=input,
result_str=str(result.target))
retval.add(response)
except DNSException as e:
duration = time.time() - start
response = DNSResponse(input=input,
duration=duration,
query_type=query_type)
response.has_error = True
response.error_str = e
retval.add(response)
elif query_type == "PTR":
if is_valid_ipv4_addr(input) or is_valid_ipv6_addr(input):
inaddr = reversename.from_address(input)
elif 'in-addr.arpa' in input.lower():
inaddr = input
else:
raise ValueError('Cannot query PTR record for "{0}"'.format(input))
try:
answer = resolver.query(inaddr, query_type)
duration = time.time() - start
for result in answer:
response = DNSResponse(query_type=query_type,
duration=duration,
input=inaddr,
result_str=str(result.target))
retval.add(response)
except DNSException as e:
duration = time.time() - start
response = DNSResponse(input=input,
duration=duration,
query_type=query_type)
response.has_error = True
response.error_str = e
retval.add(response)
elif query_type == "TXT":
try:
answer = resolver.query(input, query_type)
duration = time.time() - start
for result in answer:
response = DNSResponse(query_type=query_type,
duration=duration,
input=inaddr,
result_str=str(result.strings))
retval.add(response)
except DNSException as e:
duration = time.time() - start
response = DNSResponse(input=input,
duration=duration,
query_type=query_type)
response.has_error = True
response.error_str = e
retval.add(response)
return retval
def dns_query(input="", query_type="", server="", timeout=2.0):
"""A unified IPv4 & IPv6 DNS lookup interface; this is essentially just a wrapper around dnspython's API. When you query a PTR record, you can use an IPv4 or IPv6 address (which will automatically be converted into an in-addr.arpa name. This wrapper only supports a subset of DNS records: 'A', 'AAAA', 'CNAME', 'MX', 'NS', 'PTR', and 'TXT'
Kwargs:
- input (str): A string containing the DNS record to lookup
- query_type (str): A string containing the DNS record type (SOA not supported)
- server (str): A string containing the fqdn or IP address of the dns server
- timeout (float): DNS lookup timeout duration (default: 2.0 seconds)
Returns:
A set() of :class:`~ccp_util.DNSResponse` instances
>>> from ciscoconfparse.ccp_util import dns_query
>>> dns_query('www.pennington.net', "A", "4.2.2.2")
set([<DNSResponse "A" result_str="65.19.187.2">])
>>> answer = dns_query('www.pennington.net', 'A', '4.2.2.2')
>>> str(answer.pop())
'65.19.187.2'
>>>
"""
valid_records = set(['A', 'AAAA', 'AXFR', 'CNAME', 'MX', 'NS', 'PTR',
'TXT'])
query_type = query_type.upper()
assert query_type in valid_records
assert server!=""
assert float(timeout)>0
assert input != ""
intput = input.strip()
retval = set([])
resolver = Resolver()
resolver.server = [socket.gethostbyname(server)]
resolver.timeout = float(timeout)
resolver.lifetime = float(timeout)
start = time.time()
if (query_type=="A") or (query_type=="AAAA"):
try:
answer = resolver.query(input, query_type)
duration = time.time() - start
for result in answer:
response = DNSResponse(query_type=query_type,
duration=duration,
input=input, result_str = str(result.address))
retval.add(response)
except DNSException as e:
duration = time.time() - start
response = DNSResponse(input=input,
duration=duration, query_type=query_type)
response.has_error = True
response.error_str = e
retval.add(response)
elif query_type=="AXFR":
"""This is a hack: return text of zone transfer, instead of axfr objs"""
_zone = zone.from_xfr(query.xfr(server, input, lifetime=timeout))
return [_zone[node].to_text(node) for node in _zone.nodes.keys()]
elif query_type=="CNAME":
try:
answer = resolver.query(input, query_type)
duration = time.time() - start
for result in answer:
response = DNSResponse(query_type=query_type,
duration=duration,
input=input, result_str = str(result.target))
retval.add(response)
except DNSException as e:
duration = time.time() - start
response = DNSResponse(input=input, duration=duration,
query_type=query_type)
response.has_error = True
response.error_str = e
retval.add(response)
elif query_type=="MX":
try:
answer = resolver.query(input, query_type)
duration = time.time() - start
for result in answer:
response = DNSResponse(query_type=query_type,
input=input, result_str = str(result.target))
response.preference = int(result.preference)
retval.add(response)
except DNSException as e:
duration = time.time() - start
response = DNSResponse(input=input, duration=duration,
query_type=query_type)
response.has_error = True
response.error_str = e
retval.add(response)
elif query_type=="NS":
try:
answer = resolver.query(input, query_type)
duration = time.time() - start
for result in answer:
response = DNSResponse(query_type=query_type,
duration=duration,
input=input, result_str = str(result.target))
retval.add(response)
except DNSException as e:
duration = time.time() - start
response = DNSResponse(input=input,
duration=duration, query_type=query_type)
response.has_error = True
response.error_str = e
retval.add(response)
elif query_type=="PTR":
if is_valid_ipv4_addr(input) or is_valid_ipv6_addr(input):
inaddr = reversename.from_address(input)
elif 'in-addr.arpa' in input.lower():
inaddr = input
else:
raise ValueError('Cannot query PTR record for "{0}"'.format(input))
try:
answer = resolver.query(inaddr, query_type)
duration = time.time() - start
for result in answer:
response = DNSResponse(query_type=query_type,
duration=duration,
input=inaddr, result_str = str(result.target))
retval.add(response)
except DNSException as e:
duration = time.time() - start
response = DNSResponse(input=input,
duration=duration,
query_type=query_type)
response.has_error = True
response.error_str = e
retval.add(response)
elif query_type=="TXT":
try:
answer = resolver.query(input, query_type)
duration = time.time() - start
for result in answer:
response = DNSResponse(query_type=query_type,
duration=duration,
input=inaddr, result_str = str(result.strings))
retval.add(response)
except DNSException as e:
duration = time.time() - start
response = DNSResponse(input=input,
duration=duration, query_type=query_type)
response.has_error = True
response.error_str = e
retval.add(response)
return retval
