summaryrefslogtreecommitdiff
path: root/test/resolv/test_dns.rb
blob: 9d243bbf502b0984a9948705c7bd31f87c9ad825 (plain)
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
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
# frozen_string_literal: false
require 'test/unit'
require 'resolv'
require 'socket'
require 'tempfile'

class Object # :nodoc:
  def stub name, val_or_callable, &block
    new_name = "__minitest_stub__#{name}"

    metaclass = class << self; self; end

    if respond_to? name and not methods.map(&:to_s).include? name.to_s then
      metaclass.send :define_method, name do |*args|
        super(*args)
      end
    end

    metaclass.send :alias_method, new_name, name

    metaclass.send :define_method, name do |*args|
      if val_or_callable.respond_to? :call then
        val_or_callable.call(*args)
      else
        val_or_callable
      end
    end

    yield self
  ensure
    metaclass.send :undef_method, name
    metaclass.send :alias_method, name, new_name
    metaclass.send :undef_method, new_name
  end unless method_defined?(:stub) # lib/rubygems/test_case.rb also has the same method definition
end

class TestResolvDNS < Test::Unit::TestCase
  def setup
    @save_do_not_reverse_lookup = BasicSocket.do_not_reverse_lookup
    BasicSocket.do_not_reverse_lookup = true
  end

  def teardown
    BasicSocket.do_not_reverse_lookup = @save_do_not_reverse_lookup
  end

  def with_udp(host, port)
    u = UDPSocket.new
    begin
      u.bind(host, port)
      yield u
    ensure
      u.close
    end
  end

  # [ruby-core:65836]
  def test_resolve_with_2_ndots
    conf = Resolv::DNS::Config.new :nameserver => ['127.0.0.1'], :ndots => 2
    assert conf.single?

    candidates = []
    conf.resolv('example.com') { |candidate, *args|
      candidates << candidate
      raise Resolv::DNS::Config::NXDomain
    }
    n = Resolv::DNS::Name.create 'example.com.'
    assert_equal n, candidates.last
  end

  def test_query_ipv4_address
    begin
      OpenSSL
    rescue LoadError
      omit 'autoload problem. see [ruby-dev:45021][Bug #5786]'
    end if defined?(OpenSSL)

    with_udp('127.0.0.1', 0) {|u|
      _, server_port, _, server_address = u.addr
      begin
        client_thread = Thread.new {
          Resolv::DNS.open(:nameserver_port => [[server_address, server_port]]) {|dns|
            dns.getresources("foo.example.org", Resolv::DNS::Resource::IN::A)
          }
        }
        server_thread = Thread.new {
          msg, (_, client_port, _, client_address) = Timeout.timeout(5) {u.recvfrom(4096)}
          id, word2, qdcount, ancount, nscount, arcount = msg.unpack("nnnnnn")
          qr =     (word2 & 0x8000) >> 15
          opcode = (word2 & 0x7800) >> 11
          aa =     (word2 & 0x0400) >> 10
          tc =     (word2 & 0x0200) >> 9
          rd =     (word2 & 0x0100) >> 8
          ra =     (word2 & 0x0080) >> 7
          z =      (word2 & 0x0070) >> 4
          rcode =   word2 & 0x000f
          rest = msg[12..-1]
          assert_equal(0, qr) # 0:query 1:response
          assert_equal(0, opcode) # 0:QUERY 1:IQUERY 2:STATUS
          assert_equal(0, aa) # Authoritative Answer
          assert_equal(0, tc) # TrunCation
          assert_equal(1, rd) # Recursion Desired
          assert_equal(0, ra) # Recursion Available
          assert_equal(0, z) # Reserved for future use
          assert_equal(0, rcode) # 0:No-error 1:Format-error 2:Server-failure 3:Name-Error 4:Not-Implemented 5:Refused
          assert_equal(1, qdcount) # number of entries in the question section.
          assert_equal(0, ancount) # number of entries in the answer section.
          assert_equal(0, nscount) # number of entries in the authority records section.
          assert_equal(0, arcount) # number of entries in the additional records section.
          name = [3, "foo", 7, "example", 3, "org", 0].pack("Ca*Ca*Ca*C")
          assert_operator(rest, :start_with?, name)
          rest = rest[name.length..-1]
          assert_equal(4, rest.length)
          qtype, _ = rest.unpack("nn")
          assert_equal(1, qtype) # A
          assert_equal(1, qtype) # IN
          id = id
          qr = 1
          opcode = opcode
          aa = 0
          tc = 0
          rd = rd
          ra = 1
          z = 0
          rcode = 0
          qdcount = 0
          ancount = 1
          nscount = 0
          arcount = 0
          word2 = (qr << 15) |
                  (opcode << 11) |
                  (aa << 10) |
                  (tc << 9) |
                  (rd << 8) |
                  (ra << 7) |
                  (z << 4) |
                  rcode
          msg = [id, word2, qdcount, ancount, nscount, arcount].pack("nnnnnn")
          type = 1
          klass = 1
          ttl = 3600
          rdlength = 4
          rdata = [192,0,2,1].pack("CCCC") # 192.0.2.1 (TEST-NET address) RFC 3330
          rr = [name, type, klass, ttl, rdlength, rdata].pack("a*nnNna*")
          msg << rr
          u.send(msg, 0, client_address, client_port)
        }
        result, _ = assert_join_threads([client_thread, server_thread])
        assert_instance_of(Array, result)
        assert_equal(1, result.length)
        rr = result[0]
        assert_instance_of(Resolv::DNS::Resource::IN::A, rr)
        assert_instance_of(Resolv::IPv4, rr.address)
        assert_equal("192.0.2.1", rr.address.to_s)
        assert_equal(3600, rr.ttl)
      end
    }
  end

  def test_query_ipv4_duplicate_responses
    begin
      OpenSSL
    rescue LoadError
      omit 'autoload problem. see [ruby-dev:45021][Bug #5786]'
    end if defined?(OpenSSL)

    with_udp('127.0.0.1', 0) {|u|
      _, server_port, _, server_address = u.addr
      begin
        client_thread = Thread.new {
          Resolv::DNS.open(:nameserver_port => [[server_address, server_port]], :search => ['bad1.com', 'bad2.com', 'good.com'], ndots: 5) {|dns|
            dns.getaddress("example")
          }
        }
        server_thread = Thread.new {
          3.times do
            msg, (_, client_port, _, client_address) = Timeout.timeout(5) {u.recvfrom(4096)}
            id, flags, qdcount, ancount, nscount, arcount = msg.unpack("nnnnnn")

            qr =     (flags & 0x8000) >> 15
            opcode = (flags & 0x7800) >> 11
            aa =     (flags & 0x0400) >> 10
            tc =     (flags & 0x0200) >> 9
            rd =     (flags & 0x0100) >> 8
            ra =     (flags & 0x0080) >> 7
            z =      (flags & 0x0070) >> 4
            rcode =   flags & 0x000f
            _rest = msg[12..-1]

            questions = msg.bytes[12..-1]
            labels = []
            idx = 0
            while idx < questions.length-5
              size = questions[idx]
              labels << questions[idx+1..idx+size].pack('c*')
              idx += size+1
            end
            hostname = labels.join('.')

            if hostname == "example.good.com"
              id = id
              qr = 1
              opcode = opcode
              aa = 0
              tc = 0
              rd = rd
              ra = 1
              z = 0
              rcode = 0
              qdcount = 1
              ancount = 1
              nscount = 0
              arcount = 0
              word2 = (qr << 15) |
                      (opcode << 11) |
                      (aa << 10) |
                      (tc << 9) |
                      (rd << 8) |
                      (ra << 7) |
                      (z << 4) |
                      rcode
              msg = [id, word2, qdcount, ancount, nscount, arcount].pack("nnnnnn")
              msg << questions.pack('c*')
              type = 1
              klass = 1
              ttl = 3600
              rdlength = 4
              rdata = [52,0,2,1].pack("CCCC")
              rr = [0xc00c, type, klass, ttl, rdlength, rdata].pack("nnnNna*")
              msg << rr
              rdata = [52,0,2,2].pack("CCCC")
              rr = [0xc00c, type, klass, ttl, rdlength, rdata].pack("nnnNna*")
              msg << rr

              u.send(msg, 0, client_address, client_port)
            else
              id = id
              qr = 1
              opcode = opcode
              aa = 0
              tc = 0
              rd = rd
              ra = 1
              z = 0
              rcode = 3
              qdcount = 1
              ancount = 0
              nscount = 0
              arcount = 0
              word2 = (qr << 15) |
                      (opcode << 11) |
                      (aa << 10) |
                      (tc << 9) |
                      (rd << 8) |
                      (ra << 7) |
                      (z << 4) |
                      rcode
              msg = [id, word2, qdcount, ancount, nscount, arcount].pack("nnnnnn")
              msg << questions.pack('c*')

              u.send(msg, 0, client_address, client_port)
              u.send(msg, 0, client_address, client_port)
            end
          end
        }
        result, _ = assert_join_threads([client_thread, server_thread])
        assert_instance_of(Resolv::IPv4, result)
        assert_equal("52.0.2.1", result.to_s)
      end
    }
  end

  def test_query_ipv4_address_timeout
    with_udp('127.0.0.1', 0) {|u|
      _, port , _, host = u.addr
      start = nil
      rv = Resolv::DNS.open(:nameserver_port => [[host, port]]) {|dns|
        dns.timeouts = 0.1
        start = Time.now
        dns.getresources("foo.example.org", Resolv::DNS::Resource::IN::A)
      }
      t2 = Time.now
      diff = t2 - start
      assert rv.empty?, "unexpected: #{rv.inspect} (expected empty)"
      assert_operator 0.1, :<=, diff

      rv = Resolv::DNS.open(:nameserver_port => [[host, port]]) {|dns|
        dns.timeouts = [ 0.1, 0.2 ]
        start = Time.now
        dns.getresources("foo.example.org", Resolv::DNS::Resource::IN::A)
      }
      t2 = Time.now
      diff = t2 - start
      assert rv.empty?, "unexpected: #{rv.inspect} (expected empty)"
      assert_operator 0.3, :<=, diff
    }
  end

  def test_no_server
    omit if /mswin/ =~ RUBY_PLATFORM && ENV.key?('GITHUB_ACTIONS') # not working from the beginning
    u = UDPSocket.new
    u.bind("127.0.0.1", 0)
    _, port, _, host = u.addr
    u.close
    # A race condition here.
    # Another program may use the port.
    # But no way to prevent it.
    begin
      Timeout.timeout(5) do
        Resolv::DNS.open(:nameserver_port => [[host, port]]) {|dns|
          assert_equal([], dns.getresources("test-no-server.example.org", Resolv::DNS::Resource::IN::A))
        }
      end
    rescue Timeout::Error
      if RUBY_PLATFORM.match?(/mingw/)
        # cannot repo locally
        omit 'Timeout Error on MinGW CI'
      else
        raise Timeout::Error
      end
    end
  end

  def test_invalid_byte_comment
    bug9273 = '[ruby-core:59239] [Bug #9273]'
    Tempfile.create('resolv_test_dns_') do |tmpfile|
      tmpfile.print("\xff\x00\x40")
      tmpfile.close
      assert_nothing_raised(ArgumentError, bug9273) do
        Resolv::DNS::Config.parse_resolv_conf(tmpfile.path)
      end
    end
  end

  def test_resolv_conf_by_command
    Dir.mktmpdir do |dir|
      Dir.chdir(dir) do
        assert_raise(Errno::ENOENT, Errno::EINVAL) do
          Resolv::DNS::Config.parse_resolv_conf("|echo foo")
        end
      end
    end
  end

  def test_dots_diffences
    name1 = Resolv::DNS::Name.create("example.org")
    name2 = Resolv::DNS::Name.create("ex.ampl.eo.rg")
    assert_not_equal(name1, name2, "different dots")
  end

  def test_case_insensitive_name
    bug10550 = '[ruby-core:66498] [Bug #10550]'
    lower = Resolv::DNS::Name.create("ruby-lang.org")
    upper = Resolv::DNS::Name.create("Ruby-Lang.org")
    assert_equal(lower, upper, bug10550)
  end

  def test_ipv6_name
    addr = Resolv::IPv6.new("\0"*16)
    labels = addr.to_name.to_a
    expected = (['0'] * 32 + ['ip6', 'arpa']).map {|label| Resolv::DNS::Label::Str.new(label) }
    assert_equal(expected, labels)
  end

  def test_ipv6_create
    ref = '[Bug #11910] [ruby-core:72559]'
    assert_instance_of Resolv::IPv6, Resolv::IPv6.create('::1'), ref
    assert_instance_of Resolv::IPv6, Resolv::IPv6.create('::1:127.0.0.1'), ref
  end

  def test_ipv6_to_s
    test_cases = [
      ["2001::abcd:abcd:abcd", "2001::ABcd:abcd:ABCD"],
      ["2001:db8::1", "2001:db8::0:1"],
      ["::", "0:0:0:0:0:0:0:0"],
      ["2001::", "2001::0"],
      ["2001:db8::1:1:1:1:1", "2001:db8:0:1:1:1:1:1"],
      ["1::1:0:0:0:1", "1:0:0:1:0:0:0:1"],
      ["1::1:0:0:1", "1:0:0:0:1:0:0:1"],
    ]

    test_cases.each do |expected, ipv6|
      assert_equal expected, Resolv::IPv6.create(ipv6).to_s
    end
  end

  def test_ipv6_should_be_16
    ref = '[rubygems:1626]'

    broken_message =
      "\0\0\0\0\0\0\0\0\0\0\0\1" \
      "\x03ns2\bdnsimple\x03com\x00" \
      "\x00\x1C\x00\x01\x00\x02OD" \
      "\x00\x10$\x00\xCB\x00 I\x00\x01\x00\x00\x00\x00"

    e = assert_raise_with_message(Resolv::DNS::DecodeError, /IPv6 address must be 16 bytes/, ref) do
      Resolv::DNS::Message.decode broken_message
    end
    assert_kind_of(ArgumentError, e.cause)
  end

  def test_too_big_label_address
    n = 2000
    m = Resolv::DNS::Message::MessageEncoder.new {|msg|
      2.times {
        n.times {|i| msg.put_labels(["foo#{i}"]) }
      }
    }
    Resolv::DNS::Message::MessageDecoder.new(m.to_s) {|msg|
      2.times {
        n.times {|i|
          assert_equal(["foo#{i}"], msg.get_labels.map {|label| label.to_s })
        }
      }
    }
    assert_operator(2**14, :<, m.to_s.length)
  end

  def assert_no_fd_leak
    socket = assert_throw(self) do |tag|
      Resolv::DNS.stub(:bind_random_port, ->(s, *) {throw(tag, s)}) do
        yield.getname("8.8.8.8")
      end
    end

    assert_predicate(socket, :closed?, "file descriptor leaked")
  end

  def test_no_fd_leak_connected
    assert_no_fd_leak {Resolv::DNS.new(nameserver_port: [['127.0.0.1', 53]])}
  end

  def test_no_fd_leak_unconnected
    assert_no_fd_leak {Resolv::DNS.new}
  end

  def test_each_name
    dns = Resolv::DNS.new
    def dns.each_resource(name, typeclass)
      yield typeclass.new(name)
    end

    dns.each_name('127.0.0.1') do |ptr|
      assert_equal('1.0.0.127.in-addr.arpa', ptr.to_s)
    end
    dns.each_name(Resolv::IPv4.create('127.0.0.1')) do |ptr|
      assert_equal('1.0.0.127.in-addr.arpa', ptr.to_s)
    end
    dns.each_name('::1') do |ptr|
      assert_equal('1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa', ptr.to_s)
    end
    dns.each_name(Resolv::IPv6.create('::1')) do |ptr|
      assert_equal('1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa', ptr.to_s)
    end
    dns.each_name(Resolv::DNS::Name.create('1.0.0.127.in-addr.arpa.')) do |ptr|
      assert_equal('1.0.0.127.in-addr.arpa', ptr.to_s)
    end
    assert_raise(Resolv::ResolvError) { dns.each_name('example.com') }
  end
end