source4/scripting/python/samba/tests/dns.py

   1 #!/usr/bin/env python
   2
   3 # Unix SMB/CIFS implementation.
   4 # Copyright (C) Kai Blin  <kai@samba.org> 2011
   5 #
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 #
  19
  20 import os
  21 import sys
  22 import struct
  23 import random
  24 from samba import socket
  25 import samba.ndr as ndr
  26 import samba.dcerpc.dns as dns
  27 from samba.tests import TestCase
  28
  29 class DNSTest(TestCase):
  30
  31     def errstr(self, errcode):
  32         "Return a readable error code"
  33         string_codes = [
  34             "OK",
  35             "FORMERR",
  36             "SERVFAIL",
  37             "NXDOMAIN",
  38             "NOTIMP",
  39             "REFUSED",
  40             "YXDOMAIN",
  41             "YXRRSET",
  42             "NXRRSET",
  43             "NOTAUTH",
  44             "NOTZONE",
  45         ]
  46
  47         return string_codes[errcode]
  48
  49
  50     def assert_dns_rcode_equals(self, packet, rcode):
  51         "Helper function to check return code"
  52         p_errcode = packet.operation & 0x000F
  53         self.assertEquals(p_errcode, rcode, "Expected RCODE %s, got %s" % \
  54                             (self.errstr(rcode), self.errstr(p_errcode)))
  55
  56     def assert_dns_opcode_equals(self, packet, opcode):
  57         "Helper function to check opcode"
  58         p_opcode = packet.operation & 0x7800
  59         self.assertEquals(p_opcode, opcode, "Expected OPCODE %s, got %s" % \
  60                             (opcode, p_opcode))
  61
  62     def make_name_packet(self, opcode, qid=None):
  63         "Helper creating a dns.name_packet"
  64         p = dns.name_packet()
  65         if qid is None:
  66             p.id = random.randint(0x0, 0xffff)
  67         p.operation = opcode
  68         p.questions = []
  69         return p
  70
  71     def finish_name_packet(self, packet, questions):
  72         "Helper to finalize a dns.name_packet"
  73         packet.qdcount = len(questions)
  74         packet.questions = questions
  75
  76     def make_name_question(self, name, qtype, qclass):
  77         "Helper creating a dns.name_question"
  78         q = dns.name_question()
  79         q.name = name
  80         q.question_type = qtype
  81         q.question_class = qclass
  82         return q
  83
  84     def get_dns_domain(self):
  85         "Helper to get dns domain"
  86         return os.getenv('REALM', 'example.com').lower()
  87
  88     def dns_transaction_udp(self, packet, host=os.getenv('DC_SERVER_IP')):
  89         "send a DNS query and read the reply"
  90         s = None
  91         try:
  92             send_packet = ndr.ndr_pack(packet)
  93             s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0)
  94             s.connect((host, 53))
  95             s.send(send_packet, 0)
  96             recv_packet = s.recv(2048, 0)
  97             return ndr.ndr_unpack(dns.name_packet, recv_packet)
  98         finally:
  99             if s is not None:
 100                 s.close()
 101
 102     def dns_transaction_tcp(self, packet, host=os.getenv('DC_SERVER_IP')):
 103         "send a DNS query and read the reply"
 104         s = None
 105         try:
 106             send_packet = ndr.ndr_pack(packet)
 107             s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
 108             s.connect((host, 53))
 109             tcp_packet = struct.pack('!H', len(send_packet))
 110             tcp_packet += send_packet
 111             s.send(tcp_packet, 0)
 112             recv_packet = s.recv(0xffff + 2, 0)
 113             return ndr.ndr_unpack(dns.name_packet, recv_packet[2:])
 114         finally:
 115                 if s is not None:
 116                     s.close()
 117
 118     def test_one_a_query(self):
 119         "create a query packet containing one query record"
 120         p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
 121         questions = []
 122
 123         name = "%s.%s" % (os.getenv('DC_SERVER'), self.get_dns_domain())
 124         q = self.make_name_question(name, dns.DNS_QTYPE_A, dns.DNS_QCLASS_IN)
 125         print "asking for ", q.name
 126         questions.append(q)
 127
 128         self.finish_name_packet(p, questions)
 129         response = self.dns_transaction_udp(p)
 130         self.assert_dns_rcode_equals(response, dns.DNS_RCODE_OK)
 131         self.assert_dns_opcode_equals(response, dns.DNS_OPCODE_QUERY)
 132         self.assertEquals(response.ancount, 1)
 133         self.assertEquals(response.answers[0].rdata,
 134                           os.getenv('DC_SERVER_IP'))
 135
 136     def test_one_a_query_tcp(self):
 137         "create a query packet containing one query record via TCP"
 138         p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
 139         questions = []
 140
 141         name = "%s.%s" % (os.getenv('DC_SERVER'), self.get_dns_domain())
 142         q = self.make_name_question(name, dns.DNS_QTYPE_A, dns.DNS_QCLASS_IN)
 143         print "asking for ", q.name
 144         questions.append(q)
 145
 146         self.finish_name_packet(p, questions)
 147         response = self.dns_transaction_tcp(p)
 148         self.assert_dns_rcode_equals(response, dns.DNS_RCODE_OK)
 149         self.assert_dns_opcode_equals(response, dns.DNS_OPCODE_QUERY)
 150         self.assertEquals(response.ancount, 1)
 151         self.assertEquals(response.answers[0].rdata,
 152                           os.getenv('DC_SERVER_IP'))
 153
 154     def test_two_queries(self):
 155         "create a query packet containing two query records"
 156         p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
 157         questions = []
 158
 159         name = "%s.%s" % (os.getenv('DC_SERVER'), self.get_dns_domain())
 160         q = self.make_name_question(name, dns.DNS_QTYPE_A, dns.DNS_QCLASS_IN)
 161         questions.append(q)
 162
 163         name = "%s.%s" % ('bogusname', self.get_dns_domain())
 164         q = self.make_name_question(name, dns.DNS_QTYPE_A, dns.DNS_QCLASS_IN)
 165         questions.append(q)
 166
 167         self.finish_name_packet(p, questions)
 168         response = self.dns_transaction_udp(p)
 169         self.assert_dns_rcode_equals(response, dns.DNS_RCODE_FORMERR)
 170
 171     def test_qtype_all_query(self):
 172         "create a QTYPE_ALL query"
 173         p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
 174         questions = []
 175
 176         name = "%s.%s" % (os.getenv('DC_SERVER'), self.get_dns_domain())
 177         q = self.make_name_question(name, dns.DNS_QTYPE_ALL, dns.DNS_QCLASS_IN)
 178         print "asking for ", q.name
 179         questions.append(q)
 180
 181         self.finish_name_packet(p, questions)
 182         response = self.dns_transaction_udp(p)
 183
 184         num_answers = 1
 185         dc_ipv6 = os.getenv('DC_SERVER_IPV6')
 186         if dc_ipv6 is not None:
 187             num_answers += 1
 188
 189         self.assert_dns_rcode_equals(response, dns.DNS_RCODE_OK)
 190         self.assert_dns_opcode_equals(response, dns.DNS_OPCODE_QUERY)
 191         self.assertEquals(response.ancount, num_answers)
 192         self.assertEquals(response.answers[0].rdata,
 193                           os.getenv('DC_SERVER_IP'))
 194         if dc_ipv6 is not None:
 195             self.assertEquals(response.answers[1].rdata, dc_ipv6)
 196
 197     def test_qclass_none_query(self):
 198         "create a QCLASS_NONE query"
 199         p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
 200         questions = []
 201
 202         name = "%s.%s" % (os.getenv('DC_SERVER'), self.get_dns_domain())
 203         q = self.make_name_question(name, dns.DNS_QTYPE_ALL, dns.DNS_QCLASS_NONE)
 204         questions.append(q)
 205
 206         self.finish_name_packet(p, questions)
 207         response = self.dns_transaction_udp(p)
 208         self.assert_dns_rcode_equals(response, dns.DNS_RCODE_NOTIMP)
 209
 210 # Only returns an authority section entry in BIND and Win DNS
 211 # FIXME: Enable one Samba implements this feature
 212 #    def test_soa_hostname_query(self):
 213 #        "create a SOA query for a hostname"
 214 #        p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
 215 #        questions = []
 216 #
 217 #        name = "%s.%s" % (os.getenv('DC_SERVER'), self.get_dns_domain())
 218 #        q = self.make_name_question(name, dns.DNS_QTYPE_SOA, dns.DNS_QCLASS_IN)
 219 #        questions.append(q)
 220 #
 221 #        self.finish_name_packet(p, questions)
 222 #        response = self.dns_transaction_udp(p)
 223 #        self.assert_dns_rcode_equals(response, dns.DNS_RCODE_OK)
 224 #        self.assert_dns_opcode_equals(response, dns.DNS_OPCODE_QUERY)
 225 #        # We don't get SOA records for single hosts
 226 #        self.assertEquals(response.ancount, 0)
 227
 228     def test_soa_domain_query(self):
 229         "create a SOA query for a domain"
 230         p = self.make_name_packet(dns.DNS_OPCODE_QUERY)
 231         questions = []
 232
 233         name = self.get_dns_domain()
 234         q = self.make_name_question(name, dns.DNS_QTYPE_SOA, dns.DNS_QCLASS_IN)
 235         questions.append(q)
 236
 237         self.finish_name_packet(p, questions)
 238         response = self.dns_transaction_udp(p)
 239         self.assert_dns_rcode_equals(response, dns.DNS_RCODE_OK)
 240         self.assert_dns_opcode_equals(response, dns.DNS_OPCODE_QUERY)
 241         self.assertEquals(response.ancount, 1)
 242
 243     def test_two_updates(self):
 244         "create two update requests"
 245         p = self.make_name_packet(dns.DNS_OPCODE_UPDATE)
 246         updates = []
 247
 248         name = "%s.%s" % (os.getenv('DC_SERVER'), self.get_dns_domain())
 249         u = self.make_name_question(name, dns.DNS_QTYPE_A, dns.DNS_QCLASS_IN)
 250         updates.append(u)
 251
 252         name = self.get_dns_domain()
 253         u = self.make_name_question(name, dns.DNS_QTYPE_A, dns.DNS_QCLASS_IN)
 254         updates.append(u)
 255
 256         self.finish_name_packet(p, updates)
 257         response = self.dns_transaction_udp(p)
 258         self.assert_dns_rcode_equals(response, dns.DNS_RCODE_FORMERR)
 259
 260     def test_update_wrong_qclass(self):
 261         "create update with DNS_QCLASS_NONE"
 262         p = self.make_name_packet(dns.DNS_OPCODE_UPDATE)
 263         updates = []
 264
 265         name = self.get_dns_domain()
 266         u = self.make_name_question(name, dns.DNS_QTYPE_A, dns.DNS_QCLASS_NONE)
 267         updates.append(u)
 268
 269         self.finish_name_packet(p, updates)
 270         response = self.dns_transaction_udp(p)
 271         self.assert_dns_rcode_equals(response, dns.DNS_RCODE_NOTIMP)
 272
 273     def test_update_prereq_with_non_null_ttl(self):
 274         "test update with a non-null TTL"
 275         p = self.make_name_packet(dns.DNS_OPCODE_UPDATE)
 276         updates = []
 277
 278         name = self.get_dns_domain()
 279
 280         u = self.make_name_question(name, dns.DNS_QTYPE_SOA, dns.DNS_QCLASS_IN)
 281         updates.append(u)
 282         self.finish_name_packet(p, updates)
 283
 284         prereqs = []
 285         r = dns.res_rec()
 286         r.name = "%s.%s" % (os.getenv('DC_SERVER'), self.get_dns_domain())
 287         r.rr_type = dns.DNS_QTYPE_TXT
 288         r.rr_class = dns.DNS_QCLASS_NONE
 289         r.ttl = 1
 290         r.length = 0
 291         prereqs.append(r)
 292
 293         p.ancount = len(prereqs)
 294         p.answers = prereqs
 295
 296         response = self.dns_transaction_udp(p)
 297         self.assert_dns_rcode_equals(response, dns.DNS_RCODE_FORMERR)
 298
 299 # I'd love to test this one, but it segfaults. :)
 300 #    def test_update_prereq_with_non_null_length(self):
 301 #        "test update with a non-null length"
 302 #        p = self.make_name_packet(dns.DNS_OPCODE_UPDATE)
 303 #        updates = []
 304 #
 305 #        name = self.get_dns_domain()
 306 #
 307 #        u = self.make_name_question(name, dns.DNS_QTYPE_SOA, dns.DNS_QCLASS_IN)
 308 #        updates.append(u)
 309 #        self.finish_name_packet(p, updates)
 310 #
 311 #        prereqs = []
 312 #        r = dns.res_rec()
 313 #        r.name = "%s.%s" % (os.getenv('DC_SERVER'), self.get_dns_domain())
 314 #        r.rr_type = dns.DNS_QTYPE_TXT
 315 #        r.rr_class = dns.DNS_QCLASS_ANY
 316 #        r.ttl = 0
 317 #        r.length = 1
 318 #        prereqs.append(r)
 319 #
 320 #        p.ancount = len(prereqs)
 321 #        p.answers = prereqs
 322 #
 323 #        response = self.dns_transaction_udp(p)
 324 #        self.assert_dns_rcode_equals(response, dns.DNS_RCODE_FORMERR)
 325
 326     def test_update_prereq_nonexisting_name(self):
 327         "test update with a non-null TTL"
 328         p = self.make_name_packet(dns.DNS_OPCODE_UPDATE)
 329         updates = []
 330
 331         name = self.get_dns_domain()
 332
 333         u = self.make_name_question(name, dns.DNS_QTYPE_SOA, dns.DNS_QCLASS_IN)
 334         updates.append(u)
 335         self.finish_name_packet(p, updates)
 336
 337         prereqs = []
 338         r = dns.res_rec()
 339         r.name = "idontexist.%s" % self.get_dns_domain()
 340         r.rr_type = dns.DNS_QTYPE_TXT
 341         r.rr_class = dns.DNS_QCLASS_ANY
 342         r.ttl = 0
 343         r.length = 0
 344         prereqs.append(r)
 345
 346         p.ancount = len(prereqs)
 347         p.answers = prereqs
 348
 349         response = self.dns_transaction_udp(p)
 350         self.assert_dns_rcode_equals(response, dns.DNS_RCODE_NXRRSET)
 351
 352 if __name__ == "__main__":
 353     import unittest
 354     unittest.main()