from flask import current_app, request
from flask_restful import Resource, abort
from dns import reversename, rdatatype
from dns.resolver import NXDOMAIN, NoNameservers
from resolverapi.util import is_valid_hostname, is_valid_rdtype, is_valid_ip
from resolverapi.util.dns_query import parse_query
from resolverapi import dns_resolver
import time
from dns.exception import Timeout
class LookupRecordType(Resource):
def get(self, rdtype, domain):
t1 = time.time()
rdtype = rdtype.upper()
current_app.logger.info(
'Request from %s - %s', request.remote_addr, rdtype)
self.valid_args(rdtype, domain)
# Iterate through nameservers so that we can tell which one gets used.
nameservers = current_app.config['RESOLVERS']
for nameserver in nameservers:
dns_resolver.nameservers = [nameserver]
try:
answer = dns_resolver.query(
domain, rdtype, raise_on_no_answer=False)
# Successful query
break
except (NoNameservers, NXDOMAIN):
# TODO: this should still follow the RFC
return {'message': "No nameservers found for provided domain"}, 404
except Timeout as e:
# Communication fail or timeout - try next nameserver
if nameserver is nameservers[-1]:
current_app.logger.info(e)
return {'message': 'All nameservers timed out.'}, 503
continue
except Exception as e:
current_app.logger.error(e)
return {'message': 'An unexpected error occured.'}, 500
t2 = time.time()
duration = t2 - t1
return parse_query(answer, nameserver, duration)
def valid_args(self, rdtype, domain):
if not is_valid_rdtype(rdtype):
abort(400, message="The provided record type is not supported")
if not is_valid_hostname(domain):
abort(400, message="The provided domain name is invalid")
class ReverseLookup(Resource):
def get(self, ip):
t1 = time.time()
self.valid_args(ip)
# Iterate through nameservers so that we can tell which one gets used.
nameservers = current_app.config['RESOLVERS']
for nameserver in nameservers:
dns_resolver.nameservers = [nameserver]
try:
# http://stackoverflow.com/a/19867936/1707152
answer = dns_resolver.query(
reversename.from_address(ip), rdatatype.PTR,
raise_on_no_answer=False)
# Successful query
break
except Timeout as e:
# Communication fail or timeout - try next nameserver
if nameserver is nameservers[-1]:
current_app.logger.info(e)
return {'message': 'All nameservers timed out.'}, 503
continue
except NXDOMAIN:
return {'message': 'No nameserver found for the provided IP'}, 404
except Exception as e:
current_app.logger.error(e)
return {'message': 'An unexpected error occured.'}, 500
t2 = time.time()
duration = t2 - t1
if answer is None:
return {'message': 'An unexpected error occured.'}, 500
return parse_query(answer, nameserver, duration)
def valid_args(self, ip):
if not is_valid_ip(ip):
abort(400, message="The provided ip address is invalid")
