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#!/usr/bin/env python
# Unix SMB/CIFS implementation.
# Copyright (C) Kai Blin <kai@samba.org> 2011
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
import os
import sys
import struct
import random
from samba import socket
import samba.ndr as ndr
import samba.dcerpc.dns as dns
from samba.tests import TestCase
class DNSTest(TestCase):
def assert_dns_rcode_equals(self, packet, rcode):
"Helper function to check return code"
p_errcode = packet.operation & 0x000F
self.assertEquals(p_errcode, rcode, "Expected RCODE %s, got %s" % \
(rcode, p_errcode))
def assert_dns_opcode_equals(self, packet, opcode):
"Helper function to check opcode"
p_opcode = packet.operation & 0x7800
self.assertEquals(p_opcode, opcode, "Expected OPCODE %s, got %s" % \
(opcode, p_opcode))
def make_name_packet(self, opcode, qid=None):
"Helper creating a dns.name_packet"
p = dns.name_packet()
if qid is None:
p.id = random.randint(0x0, 0xffff)
p.operation = opcode
p.questions = []
return p
def finish_name_packet(self, packet, questions):
"Helper to finalize a dns.name_packet"
packet.qdcount = len(questions)
packet.questions = questions
def make_name_question(self, name, qtype, qclass):
"Helper creating a dns.name_question"
q = dns.name_question()
q.name = name
q.question_type = qtype
q.question_class = qclass
return q
def get_dns_domain(self):
"Helper to get dns domain"
return os.getenv('REALM', 'example.com').lower()
def test_one_a_query(self):
"create a query packet containing one query record"
p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
questions = []
name = "%s.%s" % (os.getenv('DC_SERVER'), self.get_dns_domain())
q = self.make_name_question(name, dns.DNS_QTYPE_A, dns.DNS_QCLASS_IN)
print "asking for ", q.name
questions.append(q)
self.finish_name_packet(p, questions)
response = self.dns_transaction_udp(p)
self.assert_dns_rcode_equals(response, dns.DNS_RCODE_OK)
self.assert_dns_opcode_equals(response, dns.DNS_OPCODE_QUERY)
def test_two_queries(self):
"create a query packet containing two query records"
p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
questions = []
name = "%s.%s" % (os.getenv('DC_SERVER'), self.get_dns_domain())
q = self.make_name_question(name, dns.DNS_QTYPE_A, dns.DNS_QCLASS_IN)
questions.append(q)
name = "%s.%s" % ('bogusname', self.get_dns_domain())
q = self.make_name_question(name, dns.DNS_QTYPE_A, dns.DNS_QCLASS_IN)
questions.append(q)
self.finish_name_packet(p, questions)
response = self.dns_transaction_udp(p)
self.assert_dns_rcode_equals(response, dns.DNS_RCODE_FORMERR)
def dns_transaction_udp(self, packet, host=os.getenv('DC_SERVER_IP')):
"send a DNS query and read the reply"
s = None
try:
send_packet = ndr.ndr_pack(packet)
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0)
s.connect((host, 53))
s.send(send_packet, 0)
recv_packet = s.recv(2048, 0)
return ndr.ndr_unpack(dns.name_packet, recv_packet)
finally:
if s is not None:
s.close()
if __name__ == "__main__":
import unittest
unittest.main()
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