text: # -*- coding: utf-8
  # Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
  
  # Copyright (C) 2003-2007, 2009-2011 Nominum, Inc.
  #
  # Permission to use, copy, modify, and distribute this software and its
  # documentation for any purpose with or without fee is hereby granted,
  # provided that the above copyright notice and this permission notice
  # appear in all copies.
  #
  # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
  # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
  # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  
  import unittest
  import binascii
  
  import dns.exception
  import dns.flags
  import dns.message
  import dns.name
  import dns.rdataclass
  import dns.rdatatype
  import dns.rrset
  import dns.tsig
  import dns.update
  import dns.rdtypes.ANY.OPT
  import dns.rdtypes.ANY.TSIG
  
  from tests.util import here
  
  query_text = """id 1234
  opcode QUERY
  rcode NOERROR
  flags RD
  edns 0
  eflags DO
  payload 4096
  ;QUESTION
  wwww.dnspython.org. IN A
  ;ANSWER
  ;AUTHORITY
  ;ADDITIONAL"""
  
  goodhex = (
      b"04d201000001000000000001047777777709646e73707974686f6e"
      b"036f726700000100010000291000000080000000"
  )
  
  goodwire = binascii.unhexlify(goodhex)
  
  answer_text = """id 1234
  opcode QUERY
  rcode NOERROR
  flags QR AA RD
  ;QUESTION
  dnspython.org. IN SOA
  ;ANSWER
  dnspython.org. 3600 IN SOA woof.dnspython.org. hostmaster.dnspython.org. 2003052700 3600 1800 604800 3600
  ;AUTHORITY
  dnspython.org. 3600 IN NS ns1.staff.nominum.org.
  dnspython.org. 3600 IN NS ns2.staff.nominum.org.
  dnspython.org. 3600 IN NS woof.play-bow.org.
  ;ADDITIONAL
  woof.play-bow.org. 3600 IN A 204.152.186.150
  """
  
  goodhex2 = (
      "04d2 8500 0001 0001 0003 0001"
      "09646e73707974686f6e036f726700 0006 0001"
      "c00c 0006 0001 00000e10 0028 "
      "04776f6f66c00c 0a686f73746d6173746572c00c"
      "7764289c 00000e10 00000708 00093a80 00000e10"
      "c00c 0002 0001 00000e10 0014"
      "036e7331057374616666076e6f6d696e756dc016"
      "c00c 0002 0001 00000e10 0006 036e7332c063"
      "c00c 0002 0001 00000e10 0010 04776f6f6608706c61792d626f77c016"
      "c091 0001 0001 00000e10 0004 cc98ba96"
  )
  
  
  goodwire2 = binascii.unhexlify(goodhex2.replace(" ", "").encode())
  
  query_text_2 = """id 1234
  opcode QUERY
  rcode 4095
  flags RD
  edns 0
  eflags DO
  payload 4096
  ;QUESTION
  wwww.dnspython.org. IN A
  ;ANSWER
  ;AUTHORITY
  ;ADDITIONAL"""
  
  goodhex3 = (
      b"04d2010f0001000000000001047777777709646e73707974686f6e"
      b"036f726700000100010000291000ff0080000000"
  )
  
  goodwire3 = binascii.unhexlify(goodhex3)
  
  idna_text = """id 1234
  opcode QUERY
  rcode NOERROR
  flags QR AA RD
  ;QUESTION
  Königsgäßchen. IN NS
  ;ANSWER
  Königsgäßchen. 3600 IN NS Königsgäßchen.
  """
  
  
  class MessageTestCase(unittest.TestCase):
      def test_class(self):
          m = dns.message.from_text(query_text)
          self.assertTrue(isinstance(m, dns.message.QueryMessage))
  
      def test_comparison_eq1(self):
          q1 = dns.message.from_text(query_text)
          q2 = dns.message.from_text(query_text)
          self.assertEqual(q1, q2)
  
      def test_comparison_ne1(self):
          q1 = dns.message.from_text(query_text)
          q2 = dns.message.from_text(query_text)
          q2.id = 10
          self.assertNotEqual(q1, q2)
  
      def test_comparison_ne2(self):
          q1 = dns.message.from_text(query_text)
          q2 = dns.message.from_text(query_text)
          q2.question = []
          self.assertNotEqual(q1, q2)
  
      def test_comparison_ne3(self):
          q1 = dns.message.from_text(query_text)
          self.assertNotEqual(q1, 1)
  
      def test_EDNS_to_wire1(self):
          q = dns.message.from_text(query_text)
          w = q.to_wire()
          self.assertEqual(w, goodwire)
  
      def test_EDNS_from_wire1(self):
          m = dns.message.from_wire(goodwire)
          self.assertEqual(str(m), query_text)
  
      def test_EDNS_to_wire2(self):
          q = dns.message.from_text(query_text_2)
          w = q.to_wire()
          self.assertEqual(w, goodwire3)
  
      def test_EDNS_from_wire2(self):
          m = dns.message.from_wire(goodwire3)
          self.assertEqual(str(m), query_text_2)
  
      def test_EDNS_options_wire(self):
          m = dns.message.make_query("foo", "A")
          opt = dns.edns.GenericOption(3, b"data")
          m.use_edns(options=[opt])
          m2 = dns.message.from_wire(m.to_wire())
          self.assertEqual(m2.edns, 0)
          self.assertEqual(len(m2.options), 1)
          self.assertEqual(m2.options[0], opt)
  
      def test_TooBig(self):
          def bad():
              q = dns.message.from_text(query_text)
              for i in range(0, 25):
                  rrset = dns.rrset.from_text(
                      "foo%d." % i,
                      3600,
                      dns.rdataclass.IN,
                      dns.rdatatype.A,
                      "10.0.0.%d" % i,
                  )
                  q.additional.append(rrset)
              q.to_wire(max_size=512)
  
          self.assertRaises(dns.exception.TooBig, bad)
  
      def test_answer1(self):
          a = dns.message.from_text(answer_text)
          wire = a.to_wire(want_shuffle=False)
          self.assertEqual(wire, goodwire2)
  
      def test_TrailingJunk(self):
          def bad():
              badwire = goodwire + b"\x00"
              dns.message.from_wire(badwire)
  
          self.assertRaises(dns.message.TrailingJunk, bad)
  
      def test_ShortHeader(self):
          def bad():
              badwire = b"\x00" * 11
              dns.message.from_wire(badwire)
  
          self.assertRaises(dns.message.ShortHeader, bad)
  
      def test_RespondingToResponse(self):
          def bad():
              q = dns.message.make_query("foo", "A")
              r1 = dns.message.make_response(q)
              dns.message.make_response(r1)
  
          self.assertRaises(dns.exception.FormError, bad)
  
      def test_RespondingToEDNSRequestAndSettingRA(self):
          q = dns.message.make_query("foo", "A", use_edns=0)
          r = dns.message.make_response(q, True)
          self.assertTrue(r.flags & dns.flags.RA != 0)
          self.assertEqual(r.edns, 0)
  
      def test_ExtendedRcodeSetting(self):
          m = dns.message.make_query("foo", "A")
          m.set_rcode(4095)
          self.assertEqual(m.rcode(), 4095)
          self.assertEqual(m.edns, 0)
          m.set_rcode(2)
          self.assertEqual(m.rcode(), 2)
  
      def test_EDNSVersionCoherence(self):
          m = dns.message.make_query("foo", "A")
          m.use_edns(1)
          self.assertEqual((m.ednsflags >> 16) & 0xFF, 1)
  
      def test_SettingNoEDNSOptionsImpliesNoEDNS(self):
          m = dns.message.make_query("foo", "A")
          self.assertEqual(m.edns, -1)
  
      def test_SettingEDNSFlagsImpliesEDNS(self):
          m = dns.message.make_query("foo", "A", ednsflags=dns.flags.DO)
          self.assertEqual(m.edns, 0)
  
      def test_SettingEDNSPayloadImpliesEDNS(self):
          m = dns.message.make_query("foo", "A", payload=4096)
          self.assertEqual(m.edns, 0)
  
      def test_SettingEDNSRequestPayloadImpliesEDNS(self):
          m = dns.message.make_query("foo", "A", request_payload=4096)
          self.assertEqual(m.edns, 0)
  
      def test_SettingOptionsImpliesEDNS(self):
          m = dns.message.make_query("foo", "A", options=[])
          self.assertEqual(m.edns, 0)
  
      def test_FindRRset(self):
          a = dns.message.from_text(answer_text)
          n = dns.name.from_text("dnspython.org.")
          rrs1 = a.find_rrset(a.answer, n, dns.rdataclass.IN, dns.rdatatype.SOA)
          rrs2 = a.find_rrset(dns.message.ANSWER, n, dns.rdataclass.IN, dns.rdatatype.SOA)
          self.assertEqual(rrs1, rrs2)
  
      def test_FindRRsetUnindexed(self):
          a = dns.message.from_text(answer_text)
          a.index = None
          n = dns.name.from_text("dnspython.org.")
          rrs1 = a.find_rrset(a.answer, n, dns.rdataclass.IN, dns.rdatatype.SOA)
          rrs2 = a.find_rrset(dns.message.ANSWER, n, dns.rdataclass.IN, dns.rdatatype.SOA)
          self.assertEqual(rrs1, rrs2)
  
      def test_GetRRset(self):
          a = dns.message.from_text(answer_text)
          a.index = None
          n = dns.name.from_text("dnspython.org.")
          rrs1 = a.get_rrset(a.answer, n, dns.rdataclass.IN, dns.rdatatype.SOA)
          rrs2 = a.get_rrset(dns.message.ANSWER, n, dns.rdataclass.IN, dns.rdatatype.SOA)
          self.assertEqual(rrs1, rrs2)
  
      def test_GetNonexistentRRset(self):
          a = dns.message.from_text(answer_text)
          a.index = None
          n = dns.name.from_text("dnspython.org.")
          rrs1 = a.get_rrset(a.answer, n, dns.rdataclass.IN, dns.rdatatype.TXT)
          rrs2 = a.get_rrset(dns.message.ANSWER, n, dns.rdataclass.IN, dns.rdatatype.TXT)
          self.assertTrue(rrs1 is None)
          self.assertEqual(rrs1, rrs2)
  
      def test_CleanTruncated(self):
          def bad():
              a = dns.message.from_text(answer_text)
              a.flags |= dns.flags.TC
              wire = a.to_wire(want_shuffle=False)
              dns.message.from_wire(wire, raise_on_truncation=True)
  
          self.assertRaises(dns.message.Truncated, bad)
  
      def test_MessyTruncated(self):
          def bad():
              a = dns.message.from_text(answer_text)
              a.flags |= dns.flags.TC
              wire = a.to_wire(want_shuffle=False)
              dns.message.from_wire(wire[:-3], raise_on_truncation=True)
  
          self.assertRaises(dns.message.Truncated, bad)
  
      def test_IDNA_2003(self):
          a = dns.message.from_text(idna_text, idna_codec=dns.name.IDNA_2003)
          rrs = dns.rrset.from_text_list(
              "xn--knigsgsschen-lcb0w.",
              30,
              "in",
              "ns",
              ["xn--knigsgsschen-lcb0w."],
              idna_codec=dns.name.IDNA_2003,
          )
          self.assertEqual(a.answer[0], rrs)
  
      @unittest.skipUnless(
          dns.name.have_idna_2008, "Python idna cannot be imported; no IDNA2008"
      )
      def test_IDNA_2008(self):
          a = dns.message.from_text(idna_text, idna_codec=dns.name.IDNA_2008)
          rrs = dns.rrset.from_text_list(
              "xn--knigsgchen-b4a3dun.",
              30,
              "in",
              "ns",
              ["xn--knigsgchen-b4a3dun."],
              idna_codec=dns.name.IDNA_2008,
          )
          self.assertEqual(a.answer[0], rrs)
  
      def test_bad_section_number(self):
          m = dns.message.make_query("foo", "A")
          self.assertRaises(ValueError, lambda: m.section_number(123))
  
      def test_section_from_number(self):
          m = dns.message.make_query("foo", "A")
          self.assertEqual(m.section_from_number(dns.message.QUESTION), m.question)
          self.assertEqual(m.section_from_number(dns.message.ANSWER), m.answer)
          self.assertEqual(m.section_from_number(dns.message.AUTHORITY), m.authority)
          self.assertEqual(m.section_from_number(dns.message.ADDITIONAL), m.additional)
          self.assertRaises(ValueError, lambda: m.section_from_number(999))
  
      def test_wanting_EDNS_true_is_EDNS0(self):
          m = dns.message.make_query("foo", "A")
          self.assertEqual(m.edns, -1)
          m.use_edns(True)
          self.assertEqual(m.edns, 0)
  
      def test_wanting_DNSSEC_turns_on_EDNS(self):
          m = dns.message.make_query("foo", "A")
          self.assertEqual(m.edns, -1)
          m.want_dnssec()
          self.assertEqual(m.edns, 0)
          self.assertTrue(m.ednsflags & dns.flags.DO)
  
      def test_EDNS_default_payload_is_1232(self):
          m = dns.message.make_query("foo", "A")
          m.use_edns()
          self.assertEqual(m.payload, dns.message.DEFAULT_EDNS_PAYLOAD)
  
      def test_from_file(self):
          m = dns.message.from_file(here("query"))
          expected = dns.message.from_text(query_text)
          self.assertEqual(m, expected)
  
      def test_explicit_header_comment(self):
          m = dns.message.from_text(";HEADER\n" + query_text)
          expected = dns.message.from_text(query_text)
          self.assertEqual(m, expected)
  
      def test_repr(self):
          q = dns.message.from_text(query_text)
          self.assertEqual(repr(q), "<DNS message, ID 1234>")
  
      def test_non_question_setters(self):
          rrset = dns.rrset.from_text("foo", 300, "in", "a", "10.0.0.1")
          q = dns.message.QueryMessage(id=1)
          q.answer = [rrset]
          self.assertEqual(q.sections[1], [rrset])
          self.assertEqual(q.sections[2], [])
          self.assertEqual(q.sections[3], [])
          q.authority = [rrset]
          self.assertEqual(q.sections[2], [rrset])
          self.assertEqual(q.sections[3], [])
          q.additional = [rrset]
          self.assertEqual(q.sections[3], [rrset])
  
      def test_is_a_response_empty_question(self):
          q = dns.message.make_query("www.dnspython.org.", "a")
          r = dns.message.make_response(q)
          r.question = []
          r.set_rcode(dns.rcode.FORMERR)
          self.assertTrue(q.is_response(r))
  
      def test_not_a_response(self):
          q = dns.message.QueryMessage(id=1)
          self.assertFalse(q.is_response(q))
          r = dns.message.QueryMessage(id=2)
          r.flags = dns.flags.QR
          self.assertFalse(q.is_response(r))
          r = dns.update.UpdateMessage(id=1)
          self.assertFalse(q.is_response(r))
          q1 = dns.message.make_query("www.dnspython.org.", "a")
          q2 = dns.message.make_query("www.google.com.", "a")
          # Give them the same id, as we want to test if responses for
          # differing questions are rejected.
          q1.id = 1
          q2.id = 1
          r = dns.message.make_response(q2)
          self.assertFalse(q1.is_response(r))
          # Now set rcode to FORMERR and check again.  It should still
          # not be a response as we check the question section for FORMERR
          # if it is present.
          r.set_rcode(dns.rcode.FORMERR)
          self.assertFalse(q1.is_response(r))
          # Test the other case of differing questions, where there is
          # something in the response's question section that is not in
          # the question's.  We have to do multiple questions to test
          # this :)
          r = dns.message.make_query("www.dnspython.org.", "a")
          r.flags |= dns.flags.QR
          r.id = 1
          r.find_rrset(
              r.question,
              dns.name.from_text("example"),
              dns.rdataclass.IN,
              dns.rdatatype.A,
              create=True,
              force_unique=True,
          )
          self.assertFalse(q1.is_response(r))
  
      def test_more_not_equal_cases(self):
          q1 = dns.message.make_query("www.dnspython.org.", "a")
          q2 = dns.message.make_query("www.dnspython.org.", "a")
          # ensure ids are same
          q1.id = 1
          q2.id = 1
          # and flags are different
          q2.flags |= dns.flags.QR
          self.assertFalse(q1 == q2)
          q2.flags = q1.flags
          q2.find_rrset(
              q2.question,
              dns.name.from_text("example"),
              dns.rdataclass.IN,
              dns.rdatatype.A,
              create=True,
              force_unique=True,
          )
          self.assertFalse(q1 == q2)
  
      def test_edns_properties(self):
          q = dns.message.make_query("www.dnspython.org.", "a")
          self.assertEqual(q.edns, -1)
          self.assertEqual(q.payload, 0)
          self.assertEqual(q.options, ())
          q = dns.message.make_query("www.dnspython.org.", "a", use_edns=0, payload=4096)
          self.assertEqual(q.edns, 0)
          self.assertEqual(q.payload, 4096)
          self.assertEqual(q.options, ())
  
      def test_setting_id(self):
          q = dns.message.make_query("www.dnspython.org.", "a", id=12345)
          self.assertEqual(q.id, 12345)
  
      def test_setting_flags(self):
          q = dns.message.make_query(
              "www.dnspython.org.", "a", flags=dns.flags.RD | dns.flags.CD
          )
          self.assertEqual(q.flags, dns.flags.RD | dns.flags.CD)
          self.assertEqual(q.flags, 0x0110)
  
      def test_generic_message_class(self):
          q1 = dns.message.Message(id=1)
          q1.set_opcode(dns.opcode.NOTIFY)
          q1.flags |= dns.flags.AA
          q1.find_rrset(
              q1.question,
              dns.name.from_text("example"),
              dns.rdataclass.IN,
              dns.rdatatype.SOA,
              create=True,
              force_unique=True,
          )
          w = q1.to_wire()
          q2 = dns.message.from_wire(w)
          self.assertTrue(isinstance(q2, dns.message.Message))
          self.assertFalse(isinstance(q2, dns.message.QueryMessage))
          self.assertFalse(isinstance(q2, dns.update.UpdateMessage))
          self.assertEqual(q1, q2)
  
      def test_truncated_exception_message(self):
          q = dns.message.Message(id=1)
          q.flags |= dns.flags.TC
          te = dns.message.Truncated(message=q)
          self.assertEqual(te.message(), q)
  
      def test_bad_opt(self):
          # Not in additional
          q = dns.message.Message(id=1)
          opt = dns.rdtypes.ANY.OPT.OPT(1200, dns.rdatatype.OPT, ())
          rrs = dns.rrset.from_rdata(dns.name.root, 0, opt)
          q.answer.append(rrs)
          wire = q.to_wire()
          with self.assertRaises(dns.message.BadEDNS):
              dns.message.from_wire(wire)
          # Owner name not root name
          q = dns.message.Message(id=1)
          rrs = dns.rrset.from_rdata("foo.", 0, opt)
          q.additional.append(rrs)
          wire = q.to_wire()
          with self.assertRaises(dns.message.BadEDNS):
              dns.message.from_wire(wire)
          # Multiple opts
          q = dns.message.Message(id=1)
          rrs = dns.rrset.from_rdata(dns.name.root, 0, opt)
          q.additional.append(rrs)
          q.additional.append(rrs)
          wire = q.to_wire()
          with self.assertRaises(dns.message.BadEDNS):
              dns.message.from_wire(wire)
  
      def test_bad_tsig(self):
          keyname = dns.name.from_text("key.")
          # Not in additional
          q = dns.message.Message(id=1)
          tsig = dns.rdtypes.ANY.TSIG.TSIG(
              dns.rdataclass.ANY,
              dns.rdatatype.TSIG,
              dns.tsig.HMAC_SHA256,
              0,
              300,
              b"1234",
              0,
              0,
              b"",
          )
          rrs = dns.rrset.from_rdata(keyname, 0, tsig)
          q.answer.append(rrs)
          wire = q.to_wire()
          with self.assertRaises(dns.message.BadTSIG):
              dns.message.from_wire(wire)
          # Multiple tsigs
          q = dns.message.Message(id=1)
          q.additional.append(rrs)
          q.additional.append(rrs)
          wire = q.to_wire()
          with self.assertRaises(dns.message.BadTSIG):
              dns.message.from_wire(wire)
          # Class not ANY
          tsig = dns.rdtypes.ANY.TSIG.TSIG(
              dns.rdataclass.IN,
              dns.rdatatype.TSIG,
              dns.tsig.HMAC_SHA256,
              0,
              300,
              b"1234",
              0,
              0,
              b"",
          )
          rrs = dns.rrset.from_rdata(keyname, 0, tsig)
          wire = q.to_wire()
          with self.assertRaises(dns.message.BadTSIG):
              dns.message.from_wire(wire)
  
      def test_read_no_content_message(self):
          m = dns.message.from_text(";comment")
          self.assertIsInstance(m, dns.message.QueryMessage)
  
      def test_eflags_turns_on_edns(self):
          m = dns.message.from_text("eflags DO")
          self.assertIsInstance(m, dns.message.QueryMessage)
          self.assertEqual(m.edns, 0)
  
      def test_payload_turns_on_edns(self):
          m = dns.message.from_text("payload 1200")
          self.assertIsInstance(m, dns.message.QueryMessage)
          self.assertEqual(m.payload, 1200)
  
      def test_bogus_header(self):
          with self.assertRaises(dns.message.UnknownHeaderField):
              dns.message.from_text("bogus foo")
  
      def test_question_only(self):
          m = dns.message.from_text(answer_text)
          w = m.to_wire()
          r = dns.message.from_wire(w, question_only=True)
          self.assertEqual(r.id, m.id)
          self.assertEqual(r.question[0], m.question[0])
          self.assertEqual(len(r.answer), 0)
          self.assertEqual(len(r.authority), 0)
          self.assertEqual(len(r.additional), 0)
  
      def test_bad_resolve_chaining(self):
          r = dns.message.make_query("www.dnspython.org.", "a")
          with self.assertRaises(dns.message.NotQueryResponse):
              r.resolve_chaining()
          r.flags |= dns.flags.QR
          r.id = 1
          r.find_rrset(
              r.question,
              dns.name.from_text("example"),
              dns.rdataclass.IN,
              dns.rdatatype.A,
              create=True,
              force_unique=True,
          )
          with self.assertRaises(dns.exception.FormError):
              r.resolve_chaining()
  
      def test_resolve_chaining_no_infinite_loop(self):
          r = dns.message.from_text(
              """id 1
  flags QR
  ;QUESTION
  www.example. IN CNAME
  ;AUTHORITY
  example. 300 IN SOA . . 1 2 3 4 5
  """
          )
          # passing is not going into an infinite loop in this call
          result = r.resolve_chaining()
          self.assertEqual(result.canonical_name, dns.name.from_text("www.example."))
          self.assertEqual(result.minimum_ttl, 5)
          self.assertIsNone(result.answer)
  
      def test_bad_text_questions(self):
          with self.assertRaises(dns.exception.SyntaxError):
              dns.message.from_text(
                  """id 1
  ;QUESTION
  example.
  """
              )
          with self.assertRaises(dns.exception.SyntaxError):
              dns.message.from_text(
                  """id 1
  ;QUESTION
  example. IN
  """
              )
          with self.assertRaises(dns.rdatatype.UnknownRdatatype):
              dns.message.from_text(
                  """id 1
  ;QUESTION
  example. INA
  """
              )
          with self.assertRaises(dns.rdatatype.UnknownRdatatype):
              dns.message.from_text(
                  """id 1
  ;QUESTION
  example. IN BOGUS
  """
              )
  
      def test_bad_text_rrs(self):
          with self.assertRaises(dns.exception.SyntaxError):
              dns.message.from_text(
                  """id 1
  flags QR
  ;QUESTION
  example. IN A
  ;ANSWER
  example.
  """
              )
          with self.assertRaises(dns.exception.SyntaxError):
              dns.message.from_text(
                  """id 1
  flags QR
  ;QUESTION
  example. IN A
  ;ANSWER
  example. IN
  """
              )
          with self.assertRaises(dns.exception.SyntaxError):
              dns.message.from_text(
                  """id 1
  flags QR
  ;QUESTION
  example. IN A
  ;ANSWER
  example. 300
  """
              )
          with self.assertRaises(dns.rdatatype.UnknownRdatatype):
              dns.message.from_text(
                  """id 1
  flags QR
  ;QUESTION
  example. IN A
  ;ANSWER
  example. 30a IN A
  """
              )
          with self.assertRaises(dns.rdatatype.UnknownRdatatype):
              dns.message.from_text(
                  """id 1
  flags QR
  ;QUESTION
  example. IN A
  ;ANSWER
  example. 300 INA A
  """
              )
          with self.assertRaises(dns.exception.UnexpectedEnd):
              dns.message.from_text(
                  """id 1
  flags QR
  ;QUESTION
  example. IN A
  ;ANSWER
  example. 300 IN A
  """
              )
          with self.assertRaises(dns.exception.SyntaxError):
              dns.message.from_text(
                  """id 1
  flags QR
  opcode UPDATE
  ;ZONE
  example. IN SOA
  ;UPDATE
  example. 300 IN A
  """
              )
          with self.assertRaises(dns.exception.SyntaxError):
              dns.message.from_text(
                  """id 1
  flags QR
  opcode UPDATE
  ;ZONE
  example. IN SOA
  ;UPDATE
  example. 300 NONE A
  """
              )
          with self.assertRaises(dns.exception.SyntaxError):
              dns.message.from_text(
                  """id 1
  flags QR
  opcode UPDATE
  ;ZONE
  example. IN SOA
  ;PREREQ
  example. 300 NONE A 10.0.0.1
  """
              )
          with self.assertRaises(dns.exception.SyntaxError):
              dns.message.from_text(
                  """id 1
  flags QR
  ;ANSWER
              300 IN A 10.0.0.1
  """
              )
          with self.assertRaises(dns.exception.SyntaxError):
              dns.message.from_text(
                  """id 1
  flags QR
  ;QUESTION
              IN SOA
  """
              )
  
      def test_from_wire_makes_Flag(self):
          m = dns.message.from_wire(goodwire)
          self.assertIsInstance(m.flags, dns.flags.Flag)
          self.assertEqual(m.flags, dns.flags.Flag.RD)
  
      def test_continue_on_error(self):
          good_message = dns.message.from_text(
              """id 1234
  opcode QUERY
  rcode NOERROR
  flags QR AA RD
  ;QUESTION
  www.dnspython.org. IN SOA
  ;ANSWER
  www.dnspython.org. 300 IN SOA . . 1 2 3 4 4294967295
  www.dnspython.org. 300 IN A 1.2.3.4
  www.dnspython.org. 300 IN AAAA ::1
  """
          )
          wire = good_message.to_wire()
          # change ANCOUNT to 255
          bad_wire = wire[:6] + b"\x00\xff" + wire[8:]
          # change AAAA into rdata with rdlen 0
          bad_wire = bad_wire[:-18] + b"\x00" * 2
          m = dns.message.from_wire(bad_wire, continue_on_error=True)
          self.assertEqual(len(m.errors), 2)
          print(m.errors)
          self.assertEqual(str(m.errors[0].exception), "IPv6 addresses are 16 bytes long")
          self.assertEqual(str(m.errors[1].exception), "DNS message is malformed.")
          expected_message = dns.message.from_text(
              """id 1234
  opcode QUERY
  rcode NOERROR
  flags QR AA RD
  ;QUESTION
  www.dnspython.org. IN SOA
  ;ANSWER
  www.dnspython.org. 300 IN SOA . . 1 2 3 4 4294967295
  www.dnspython.org. 300 IN A 1.2.3.4
  """
          )
          self.assertEqual(m, expected_message)
  
  
  if __name__ == "__main__":
      unittest.main()
  