Class: Dnsruby::Resolver

Inherits:
Object
  • Object
show all
Defined in:
lib/Dnsruby/Resolver.rb

Overview

Description

Dnsruby::Resolver is a DNS stub resolver. This class performs queries with retries across multiple nameservers. The system configured resolvers are used by default.

The retry policy is a combination of the Net::DNS and dnsjava approach, and has the option of :

  • A total timeout for the query (defaults to 0, meaning “no total timeout”)

  • A retransmission system that targets the namervers concurrently once the first query round is

complete, but in which the total time per query round is split between the number of nameservers 
targetted for the first round. and total time for query round is doubled for each query round

Note that, if a total timeout is specified, then that will apply regardless of the retry policy (i.e. it may cut retries short).

Note also that these timeouts are distinct from the SingleResolver’s packet_timeout

Timeouts apply to the initial query and response. If DNSSEC validation is to be performed, then additional queries may be required (these are performed automatically by Dnsruby). Each additional query will be performed with its own timeouts. So, even with a query_timeout of 5 seconds, a response which required extensive validation may take several times that long. (Future versions of Dnsruby may expose finer-grained events for client tracking of responses and validation)

Methods

Synchronous

These methods raise an exception or return a response message with rcode==NOERROR

  • Dnsruby::Resolver#send_message(msg)

  • Dnsruby::Resolver#query(name [, type [, klass]])

Asynchronous

These methods use a response queue to return the response and the error

  • Dnsruby::Resolver#send_async(msg, response_queue, query_id)

Event Loop

Dnsruby runs a pure Ruby event loop to handle I/O in a single thread. Support for EventMachine has been deprecated.

Direct Known Subclasses

SingleResolver

Defined Under Namespace

Classes: EventType

Constant Summary collapse

DefaultQueryTimeout = 
0
DefaultPacketTimeout = 
5
DefaultRetryTimes = 
1
DefaultRetryDelay = 
5
DefaultPort = 
53
DefaultDnssec = 
true
AbsoluteMinDnssecUdpSize = 
1220
MinDnssecUdpSize = 
4096
DefaultUDPSize = 
MinDnssecUdpSize

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Resolver

Create a new Resolver object. If no parameters are passed in, then the default system configuration will be used. Otherwise, a Hash may be passed in with the following optional elements :

  • :port

  • :use_tcp

  • :tsig

  • :ignore_truncation

  • :src_address

  • :src_port

  • :recurse

  • :udp_size

  • :config_info - see Config

  • :nameserver - can be either a String or an array of Strings

  • :packet_timeout

  • :query_timeout

  • :retry_times

  • :retry_delay

  • :do_caching



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
 
# File 'lib/Dnsruby/Resolver.rb', line 373

def initialize(*args)
  # @TODO@ Should we allow :namesver to be an RRSet of NS records? Would then need to randomly order them?
  @resolver_ruby = nil
  @src_address = nil
  @single_res_mutex = Mutex.new
  @configured = false
  @do_caching = true
  @config = Config.new()
  reset_attributes
  
  # Process args
  if (args.length==1)
    if (args[0].class == Hash)
      args[0].keys.each do |key|
        begin
          if (key == :config_info)
            @config.set_config_info(args[0][:config_info])
          elsif (key==:nameserver)
            set_config_nameserver(args[0][:nameserver])
          elsif (key==:nameservers)
            set_config_nameserver(args[0][:nameservers])
          else
            send(key.to_s+"=", args[0][key])
          end
        rescue Exception => e
          Dnsruby.log.error{"Argument #{key} not valid : #{e}\n"}
        end
      end
    elsif (args[0].class == String)
      set_config_nameserver(args[0])          
    elsif (args[0].class == Config)
      # also accepts a Config object from Dnsruby::Resolv
      @config = args[0]
    end
  else
    # Anything to do?
  end
  #      if (@single_resolvers==[])
  #        add_config_nameservers
  #      end
  update
  #      ResolverRegister::register_resolver(self)
end

Instance Attribute Details

#config ⇒ Object (readonly)

The current Config



105
106
107
 
# File 'lib/Dnsruby/Resolver.rb', line 105

def config
  @config
end

#dnssec ⇒ Object

Use DNSSEC for this Resolver



141
142
143
 
# File 'lib/Dnsruby/Resolver.rb', line 141

def dnssec
  @dnssec
end

#do_caching ⇒ Object

Defines whether we will cache responses, or pass every request to the upstream resolver. This is only really useful when querying authoritative servers (as the upstream recursive resolver is likely to cache)



108
109
110
 
# File 'lib/Dnsruby/Resolver.rb', line 108

def do_caching
  @do_caching
end

#do_validation ⇒ Object

Defines whether validation is performed by default on this Resolver when the query method is called. Note that send_message and send_async expect a Message object to be passed in, which is already configured to the callers requirements.



148
149
150
 
# File 'lib/Dnsruby/Resolver.rb', line 148

def do_validation
  @do_validation
end

#ignore_truncation ⇒ Object

Should truncation be ignored? i.e. the TC bit is ignored and thus the resolver will not requery over TCP if TC is set



93
94
95
 
# File 'lib/Dnsruby/Resolver.rb', line 93

def ignore_truncation
  @ignore_truncation
end

#no_tcp ⇒ Object

If no_tcp==true, then ONLY UDP will be used as a transport. This should not generally be used, but is provided as a debugging aid.



86
87
88
 
# File 'lib/Dnsruby/Resolver.rb', line 86

def no_tcp
  @no_tcp
end

#packet_timeout ⇒ Object

The timeout for any individual packet. This is the timeout used by SingleResolver



126
127
128
 
# File 'lib/Dnsruby/Resolver.rb', line 126

def packet_timeout
  @packet_timeout
end

#port ⇒ Object

The port to send queries to on the resolver



78
79
80
 
# File 'lib/Dnsruby/Resolver.rb', line 78

def port
  @port
end

#query_timeout ⇒ Object

Note that this timeout represents the total time a query may run for - multiple packets can be sent to multiple nameservers in this time. This is distinct from the SingleResolver per-packet timeout The query_timeout is not required - it will default to 0, which means “do not use query_timeout”. If this is the case then the timeout will be dictated by the retry_times and retry_delay attributes



133
134
135
 
# File 'lib/Dnsruby/Resolver.rb', line 133

def query_timeout
  @query_timeout
end

#recurse ⇒ Object

Should the Recursion Desired bit be set?



99
100
101
 
# File 'lib/Dnsruby/Resolver.rb', line 99

def recurse
  @recurse
end

#retry_delay ⇒ Object

The query will be tried across nameservers retry_times times, with a delay of retry_delay seconds between each retry. The first time round, retry_delay will be divided by the number of nameservers being targetted, and a new nameserver will be queried with the resultant delay.



138
139
140
 
# File 'lib/Dnsruby/Resolver.rb', line 138

def retry_delay
  @retry_delay
end

#retry_times ⇒ Object

The query will be tried across nameservers retry_times times, with a delay of retry_delay seconds between each retry. The first time round, retry_delay will be divided by the number of nameservers being targetted, and a new nameserver will be queried with the resultant delay.



138
139
140
 
# File 'lib/Dnsruby/Resolver.rb', line 138

def retry_times
  @retry_times
end

#src_address ⇒ Object

The source address to send queries from



96
97
98
 
# File 'lib/Dnsruby/Resolver.rb', line 96

def src_address
  @src_address
end

#tsig ⇒ Object

Returns the value of attribute tsig.



89
90
91
 
# File 'lib/Dnsruby/Resolver.rb', line 89

def tsig
  @tsig
end

#udp_size ⇒ Object

The maximum UDP size to be used



102
103
104
 
# File 'lib/Dnsruby/Resolver.rb', line 102

def udp_size
  @udp_size
end

#use_tcp ⇒ Object

Should TCP be used as a transport rather than UDP? If use_tcp==true, then ONLY TCP will be used as a transport.



82
83
84
 
# File 'lib/Dnsruby/Resolver.rb', line 82

def use_tcp
  @use_tcp
end

Class Method Details

.check_port(p, src_port = []) ⇒ Object 



593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
 
# File 'lib/Dnsruby/Resolver.rb', line 593

def Resolver.check_port(p, src_port=[])
  if (p.class != Fixnum)
    tmp_src_ports = Array.new(src_port)
    p.each do |x|
      if (!Resolver.check_port(x, tmp_src_ports))
        return false
      end
      tmp_src_ports.push(x)
    end
    return true
  end
  if (Resolver.port_in_range(p))
    if ((p == 0) && (src_port.length > 0))
      return false
    end
    return true
  else
    Dnsruby.log.error("Illegal port (#{p})")
    raise ArgumentError.new("Illegal port #{p}")
  end
end

.get_ports_from(p) ⇒ Object 



625
626
627
628
629
630
631
632
633
634
635
 
# File 'lib/Dnsruby/Resolver.rb', line 625

def Resolver.get_ports_from(p)
  a = []
  if (p.class == Fixnum)
    a = [p]
  else
    p.each do |x|
      a.push(x)
    end
  end
  return a
end

.get_tsig(args) ⇒ Object 



659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
 
# File 'lib/Dnsruby/Resolver.rb', line 659

def Resolver.get_tsig(args)
  tsig = nil
  if (args.length == 1)
    if (args[0])
      if (args[0].instance_of?RR::TSIG)
        tsig = args[0]
      elsif (args[0].instance_of?Array)
        if (args[0].length > 2)
          tsig = RR.new_from_hash({:type => Types.TSIG, :klass => Classes.ANY, :name => args[0][0], :key => args[0][1], :algorithm => args[0][2]})
        else
          tsig = RR.new_from_hash({:type => Types.TSIG, :klass => Classes.ANY, :name => args[0][0], :key => args[0][1]})
        end
      end
    else
      #          Dnsruby.log.debug{"TSIG signing switched off"}
      return nil
    end
  elsif (args.length ==2)
    tsig = RR.new_from_hash({:type => Types.TSIG, :klass => Classes.ANY, :name => args[0], :key => args[1]})
  elsif (args.length ==3)
    tsig = RR.new_from_hash({:type => Types.TSIG, :klass => Classes.ANY, :name => args[0], :key => args[1], :algorithm => args[2]})
  else
    raise ArgumentError.new("Wrong number of arguments to tsig=")
  end
  Dnsruby.log.info{"TSIG signing now using #{tsig.name}, key=#{tsig.key}"}
  return tsig
end

.port_in_range(p) ⇒ Object 



615
616
617
618
619
620
621
622
623
 
# File 'lib/Dnsruby/Resolver.rb', line 615

def Resolver.port_in_range(p)
  if ((p == 0) || ((p >= 50000) && (p <= 65535)))
    # @TODO@ IANA port bitmap - use 50000 - 65535 for now
    #            ((Iana::IANA_PORTS.index(p)) == nil &&
    #              (p > 1024) && (p < 65535)))
    return true
  end
  return false
end

Instance Method Details

#add_config_nameservers ⇒ Object

:nodoc: all



417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
 
# File 'lib/Dnsruby/Resolver.rb', line 417

def add_config_nameservers # :nodoc: all
  if (!@configured)
    @config.get_ready
  end
  @configured = true
  @single_res_mutex.synchronize {
    # Add the Config nameservers
    @config.nameserver.each do |ns|
      res = PacketSender.new({:server=>ns, :dnssec=>@dnssec,
          :use_tcp=>@use_tcp, :no_tcp=>@no_tcp, :packet_timeout=>@packet_timeout,
          :tsig => @tsig, :ignore_truncation=>@ignore_truncation,
          :src_address=>@src_address, :src_port=>@src_port,
          :recurse=>@recurse, :udp_size=>@udp_size})
      @single_resolvers.push(res) if res
    end
  }
end

#add_server(server) ⇒ Object

# Add a new SingleResolver to the list of resolvers this Resolver object will

# query.
def add_resolver(internal) # :nodoc:
  # @TODO@ Make a new PacketSender from this SingleResolver!!
  @single_resolvers.push(internal)
end

Raises:

  • (ArgumentError) 


500
501
502
503
504
505
506
507
508
 
# File 'lib/Dnsruby/Resolver.rb', line 500

def add_server(server)# :nodoc:
  @configured = true
  res = PacketSender.new(server)
  raise ArgumentError.new("Can't create server #{server}") if !res
  update_internal_res(res)
  @single_res_mutex.synchronize {
    @single_resolvers.push(res)
  }
end

#add_src_port(p) ⇒ Object

Can be a single Fixnum or a Range or an Array If an invalid port is selected (one reserved by IANA), then an ArgumentError will be raised. “0” means “any valid port” - this is only a viable option if it is the only port in the list. An ArgumentError will be raised if “0” is added to an existing set of source ports.

res.add_src_port(60000)
res.add_src_port([60001,60005,60010])
res.add_src_port(60015..60115)



580
581
582
583
584
585
586
587
588
589
590
591
 
# File 'lib/Dnsruby/Resolver.rb', line 580

def add_src_port(p)
  if (Resolver.check_port(p, @src_port))
    a = Resolver.get_ports_from(p)
    a.each do |x|
      if ((@src_port.length > 0) && (x == 0))
        raise ArgumentError.new("src_port of 0 only allowed as only src_port value (currently #{@src_port.length} values")
      end
      @src_port.push(x)
    end
  end
  update
end

#close ⇒ Object

Close the Resolver. Unfinished queries are terminated with OtherResolvError.



349
350
351
 
# File 'lib/Dnsruby/Resolver.rb', line 349

def close
  @resolver_ruby.close if @resolver_ruby
end

#generate_timeouts(base = 0) ⇒ Object

:nodoc: all



743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
 
# File 'lib/Dnsruby/Resolver.rb', line 743

def generate_timeouts(base=0) #:nodoc: all
  #These should be be pegged to the single_resolver they are targetting :
  #  e.g. timeouts[timeout1]=nameserver
  timeouts = {}
  retry_delay = @retry_delay
  #      @single_res_mutex.synchronize {
  @retry_times.times do |retry_count|
    if (retry_count>0)
      retry_delay *= 2
    end

    @single_resolvers.delete(nil) # Just in case...
    @single_resolvers.each_index do |i|
      res= @single_resolvers[i]
      offset = (i*@retry_delay.to_f/@single_resolvers.length)
      if (retry_count==0)
        timeouts[base+offset]=[res, retry_count]
      else
        if (timeouts.has_key?(base+retry_delay+offset))
          Dnsruby.log.error{"Duplicate timeout key!"}
          raise RuntimeError.new("Duplicate timeout key!")
        end
        timeouts[base+retry_delay+offset]=[res, retry_count]
      end
    end
  end
  #      }
  return timeouts      
end

#nameserver=(n) ⇒ Object 



522
523
524
525
526
527
528
529
 
# File 'lib/Dnsruby/Resolver.rb', line 522

def nameserver=(n)
  @configured = true
  @single_res_mutex.synchronize {
    @single_resolvers=[]
  }
  set_config_nameserver(n)
  add_config_nameservers
end

#nameservers=(ns) ⇒ Object 



519
520
521
 
# File 'lib/Dnsruby/Resolver.rb', line 519

def nameservers=(ns)
  self.nameserver=(ns)
end

#persistent_tcp=(on) ⇒ Object 



703
704
705
706
 
# File 'lib/Dnsruby/Resolver.rb', line 703

def persistent_tcp=(on)
  @persistent_tcp = on
  update
end

#persistent_udp=(on) ⇒ Object 



708
709
710
711
 
# File 'lib/Dnsruby/Resolver.rb', line 708

def persistent_udp=(on)
  @persistent_udp = on
  update
end

#query(name, type = Types.A, klass = Classes.IN, set_cd = @dnssec) ⇒ Object

Query for a name. If a valid Message is received, then it is returned to the caller. Otherwise an exception (a Dnsruby::ResolvError or Dnsruby::ResolvTimeout) is raised.

require 'Dnsruby'
res = Dnsruby::Resolver.new
response = res.query("example.com") # defaults to Types.A, Classes.IN
response = res.query("example.com", Types.MX)
response = res.query("208.77.188.166") # IPv4 address so PTR query will be made
response = res.query("208.77.188.166", Types.PTR)



170
171
172
173
174
175
176
177
178
179
180
 
# File 'lib/Dnsruby/Resolver.rb', line 170

def query(name, type=Types.A, klass=Classes.IN, set_cd=@dnssec)
  msg = Message.new
  msg.do_caching = @do_caching
  msg.header.rd = 1
  msg.add_question(name, type, klass)
  msg.do_validation = @do_validation
  if (@dnssec)
    msg.header.cd = set_cd # We do our own validation by default
  end
  return send_message(msg)
end

#query_no_validation_or_recursion(name, type = Types.A, klass = Classes.IN) ⇒ Object

:nodoc: all



182
183
184
185
186
187
188
189
190
191
192
 
# File 'lib/Dnsruby/Resolver.rb', line 182

def query_no_validation_or_recursion(name, type=Types.A, klass=Classes.IN) # :nodoc: all
  msg = Message.new
  msg.do_caching = @do_caching
  msg.header.rd = false
  msg.do_validation = false
  msg.add_question(name, type, klass)
  if (@dnssec)
    msg.header.cd = true # We do our own validation by default
  end
  return send_message(msg)
end

#reset_attributes ⇒ Object

:nodoc: all



449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
 
# File 'lib/Dnsruby/Resolver.rb', line 449

def reset_attributes #:nodoc: all
  if (@resolver_ruby)
    @resolver_ruby.reset_attributes
  end
 
  # Attributes

  # do_validation tells the Resolver whether to try to validate the response
  # with DNSSEC. This should work for NSEC-signed domains, but NSEC3
  # validation is not currently supported. This attribute now defaults to
  # false. Please let me know if you require NSEC3 validation.
  @do_validation = false
  @query_timeout = DefaultQueryTimeout
  @retry_delay = DefaultRetryDelay
  @retry_times = DefaultRetryTimes
  @packet_timeout = DefaultPacketTimeout
  @port = DefaultPort
  @udp_size = DefaultUDPSize
  @dnssec = DefaultDnssec
  @do_caching= true
  @use_tcp = false
  @no_tcp = false
  @tsig = nil
  @ignore_truncation = false
  @config = Config.new()
  @src_address        = nil
  @src_port        = [0]
  @recurse = true
  @single_res_mutex.synchronize {
    @single_resolvers=[]
  }
  @configured = false
end

#send_async(*args) ⇒ Object

Asynchronously send a Message to the server. The send can be done using just Dnsruby. Support for EventMachine has been deprecated.

Dnsruby pure Ruby event loop :

A client_queue is supplied by the client, along with an optional client_query_id to identify the response. The client_query_id is generated, if not supplied, and returned to the client. When the response is known, a tuple of (query_id, response_message, exception) will be added to the client_queue.

The query is sent synchronously in the caller’s thread. The select thread is then used to listen for and process the response (up to pushing it to the client_queue). The client thread is then used to retrieve the response and deal with it.

Takes :

  • msg - the message to send

  • client_queue - a Queue to push the response to, when it arrives

  • client_query_id - an optional ID to identify the query to the client

  • use_tcp - whether to use only TCP (defaults to SingleResolver.use_tcp)

Returns :

  • client_query_id - to identify the query response to the client. This ID is

generated if it is not passed in by the client

Example invocations :

id = res.send_async(msg, queue)
NOT SUPPORTED : id = res.send_async(msg, queue, use_tcp)
id = res.send_async(msg, queue, id)
id = res.send_async(msg, queue, id, use_tcp)

Example code :

require 'Dnsruby'
res = Dnsruby::Resolver.newsend
query_id = 10 # can be any object you like
query_queue = Queue.new
res.send_async(Message.new("example.com", Types.MX),  query_queue, query_id)
query_id_2 = res.send_async(Message.new("example.com", Types.A), query_queue)
# ...do a load of other stuff here...
2.times do 
  response_id, response, exception = query_queue.pop
  # You can check the ID to see which query has been answered
  if (exception == nil)
      # deal with good response
  else
      # deal with problem
  end
end



329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
 
# File 'lib/Dnsruby/Resolver.rb', line 329

def send_async(*args) # msg, client_queue, client_query_id)
  if (!@configured)
    add_config_nameservers
  end
  #      @single_res_mutex.synchronize {
  if (!@resolver_ruby) # @TODO@ Synchronize this?
    @resolver_ruby = ResolverRuby.new(self)
  end
  #      }
  client_query_id = @resolver_ruby.send_async(*args)
  if (@single_resolvers.length == 0)
    Thread.start {
      sleep(@query_timeout == 0 ? 1 : @query_timeout)
      args[1].push([client_query_id, nil, ResolvTimeout.new("Query timed out - no nameservers configured")])
    }
  end
  return client_query_id
end

#send_message(message) ⇒ Object

Send a message, and wait for the response. If a valid Message is received, then it is returned to the caller. Otherwise an exception (a Dnsruby::ResolvError or Dnsruby::ResolvTimeout) is raised.

send_async is called internally.

example :

require 'dnsruby'
include Dnsruby
res = Dnsruby::Resolver.new
begin
response = res.send_message(Message.new("example.com", Types.MX))
rescue ResolvError
  # ...
rescue ResolvTimeout
  # ...
end



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
 
# File 'lib/Dnsruby/Resolver.rb', line 211

def send_message(message)
  Dnsruby.log.debug{"Resolver : sending message"}
  q = Queue.new
  send_async(message, q)
  #      # @TODO@ Add new queue tuples, e.g. :
  #      event_type = EventType::RECEIVED
  #      reply = nil
  #      while (event_type == EventType::RECEIVED)
  #        id, event_type, reply, error = q.pop
  #        Dnsruby.log.debug{"Resolver : result received"}
  #        if ((error != nil) && (event_type == EventType::ERROR))
  #          raise error
  #        end
  #        print "Reply = #{reply}\n"
  #      end
  #      print "Reply = #{reply}\n"
  #      return reply

  id, result, error = q.pop

  if (error != nil)
    raise error
  else
    return result
  end
end

#send_plain_message(message) ⇒ Object

This method takes a Message (supplied by the client), and sends it to the configured nameservers. No changes are made to the Message before it is sent (TSIG signatures will be applied if configured on the Resolver). Retries are handled as the Resolver is configured to do. Incoming responses to the query are not cached or validated (although TCP fallback will be performed if the TC bit is set and the (Single)Resolver has ignore_truncation set to false). Note that the Message is left untouched - this means that no OPT records are added, even if the UDP transport for the server is specified at more than 512 bytes. If it is desired to use EDNS for this packet, then you should call the Dnsruby::PacketSender#prepare_for_dnssec(msg), or Dnsruby::PacketSender#add_opt_rr(msg) The return value from this method is the [response, error] tuple. Either of these values may be nil - it is up to the client to check.

example :

require 'dnsruby'
include Dnsruby
res = Dnsruby::Resolver.new
response, error = res.send_plain_message(Message.new("example.com", Types.MX))
if (error)
  print "Error returned : #{error}\n"
else
  process_response(response)
end



264
265
266
267
268
269
270
271
272
273
 
# File 'lib/Dnsruby/Resolver.rb', line 264

def send_plain_message(message)
  Dnsruby::TheLog.debug("Resolver : send_plain_message")
  message.do_caching = false
  message.do_validation = false
  message.send_raw = true
  q = Queue.new
  send_async(message, q)
  id, result, error = q.pop
  return [result, error]
end

#set_config_nameserver(n) ⇒ Object 



435
436
437
438
439
440
441
442
443
444
445
446
447
 
# File 'lib/Dnsruby/Resolver.rb', line 435

def set_config_nameserver(n)
  # @TODO@ Should we allow NS RRSet here? If so, then .sort_by {rand}
  if (!@configured)
    @config.get_ready
  end
  @configured = true
  if (n).kind_of?String
    @config.nameserver=[n]
  else
    @config.nameserver=n
  end
  add_config_nameservers
end

#single_res_mutex ⇒ Object

:nodoc: all



739
740
741
 
# File 'lib/Dnsruby/Resolver.rb', line 739

def single_res_mutex # :nodoc: all
  return @single_res_mutex
end

#single_resolvers ⇒ Object

}



118
119
120
121
122
123
 
# File 'lib/Dnsruby/Resolver.rb', line 118

def single_resolvers # :nodoc:
  if (!@configured)
    add_config_nameservers
  end
  return @single_resolvers
end

#single_resolvers=(s) ⇒ Object

The array of SingleResolvers used for sending query messages

attr_accessor :single_resolvers # :nodoc:



112
113
114
115
116
117
 
# File 'lib/Dnsruby/Resolver.rb', line 112

def single_resolvers=(s) # :nodoc:
  @configured = true
  #      @single_res_mutex.synchronize {
  @single_resolvers = s
  #      }
end

#src_port ⇒ Object

The source port to send queries from Returns either a single Fixnum or an Array e.g. “0”, or “[60001, 60002, 60007]”

Defaults to 0 - random port



546
547
548
549
550
551
 
# File 'lib/Dnsruby/Resolver.rb', line 546

def src_port
  if (@src_port.length == 1) 
    return @src_port[0]
  end
  return @src_port
end

#src_port=(p) ⇒ Object

Can be a single Fixnum or a Range or an Array If an invalid port is selected (one reserved by IANA), then an ArgumentError will be raised.

res.src_port=0
res.src_port=[60001,60005,60010]
res.src_port=60015..60115



561
562
563
564
565
566
 
# File 'lib/Dnsruby/Resolver.rb', line 561

def src_port=(p)
  if (Resolver.check_port(p))
    @src_port = Resolver.get_ports_from(p)
    update
  end
end

#update ⇒ Object

:nodoc: all



483
484
485
486
487
488
489
490
491
 
# File 'lib/Dnsruby/Resolver.rb', line 483

def update #:nodoc: all
  #Update any resolvers we have with the latest config
  @single_res_mutex.synchronize {
    @single_resolvers.delete(nil) # Just in case...
    @single_resolvers.each do |res|
      update_internal_res(res)
    end
  }
end

#update_internal_res(res) ⇒ Object 



510
511
512
513
514
515
516
517
 
# File 'lib/Dnsruby/Resolver.rb', line 510

def update_internal_res(res)
  [:port, :use_tcp, :no_tcp, :tsig, :ignore_truncation, :packet_timeout,
    :src_address, :src_port, :recurse,
    :udp_size, :dnssec].each do |param|

    res.send(param.to_s+"=", instance_variable_get("@"+param.to_s))
  end
end