1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
|
#!/usr/bin/env python2.7
# Copyright 2015 gRPC authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Makes DNS queries for A records to specified servers"""
import argparse
import signal
import twisted.internet.task as task
import twisted.names.client as client
def main():
argp = argparse.ArgumentParser(description='Make DNS queries for A records')
argp.add_argument('-s', '--server_host', default='127.0.0.1', type=str,
help='Host for DNS server to listen on for TCP and UDP.')
argp.add_argument('-p', '--server_port', default=53, type=int,
help='Port that the DNS server is listening on.')
argp.add_argument('-n', '--qname', default=None, type=str,
help=('Name of the record to query for. '))
argp.add_argument('-t', '--timeout', default=1, type=int,
help=('Force process exit after this number of seconds.'))
args = argp.parse_args()
signal.alarm(args.timeout)
def OnResolverResultAvailable(result):
answers, authority, additional = result
for a in answers:
print(a.payload)
def BeginQuery(reactor, qname):
servers = [(args.server_host, args.server_port)]
resolver = client.Resolver(servers=servers)
deferred_result = resolver.lookupAddress(args.qname)
deferred_result.addCallback(OnResolverResultAvailable)
return deferred_result
task.react(BeginQuery, [args.qname])
if __name__ == '__main__':
main()
|
