Class: Net::DNS::MDNS::Service

Inherits:
Object
  • Object
show all
Includes:
Net::DNS
Defined in:
lib/net/dns/mdns.rb

Overview

BackgroundQuery

Constant Summary

Constants included from Net::DNS

DecodeError, Net::DNS::Message, Name

Instance Method Summary collapse

Methods included from Net::DNS

rrname

Constructor Details

#initialize(name, type, port, txt = {}, target = nil, &proc) ⇒ Service

Returns a new instance of Service.



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# File 'lib/net/dns/mdns.rb', line 1054

def initialize(name, type, port, txt = {}, target = nil, &proc)
  # TODO - escape special characters
  @name = DNS::Name.create(name.to_str)
  @type = DNS::Name.create(type.to_str)
  @domain = DNS::Name.create('local')
  @port = port.to_int
  if target
    @target = DNS::Name.create(target)
    @hostrr = nil
  else
    @target = Responder.instance.hostname
    @hostrr = Responder.instance.hostrr
  end

  @txt = txt || {}
  @ttl = nil
  @priority = 0
  @weight = 0

  proc.call(self) if proc

  @srvttl = @ttl ||  240
  @ptrttl = @ttl || 7200

  @domain = Name.new(@domain.to_a, true)
  @type = @type + @domain
  @instance = @name + @type
  @enum = Name.create('_services._dns-sd._udp.') + @domain

  # build the RRs

  @rrenum = IN::PTR.new(@type)

  @rrptr = IN::PTR.new(@instance)

  @rrsrv = IN::SRV.new(@priority, @weight, @port, @target)

  strings = @txt.map { |k,v| k + '=' + v }

  @rrtxt = IN::TXT.new(*strings)

  # class << self
  #   undef_method 'ttl='
  # end
  #  -or-
  # undef :ttl=
  #
  # TODO - all the others

  start
end

Instance Method Details

#[]=(key, value) ⇒ Object

Set key/value pairs in a TXT record associated with SRV.



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# File 'lib/net/dns/mdns.rb', line 1042

def []=(key, value)
  @txt[key.to_str] = value.to_str
end

#answer_question(name, rtype, amsg) ⇒ Object

Questions we can answer: @instance:

name.type.domain -> SRV, TXT

@type:

type.domain -> PTR:name.type.domain

@enum:

_services._dns-sd._udp.<domain> -> PTR:type.domain



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# File 'lib/net/dns/mdns.rb', line 983

def answer_question(name, rtype, amsg)
  case name
  when @instance
    # See [DNSSD:14.2]
    case rtype.object_id
    when IN::ANY.object_id
      amsg.add_question(name, rtype)
      amsg.add_answer(@instance, @srvttl, @rrsrv)
      amsg.add_answer(@instance, @srvttl, @rrtxt)
      amsg.add_additional(*@hostrr) if @hostrr
 
    when IN::SRV.object_id
      amsg.add_question(name, rtype)
      amsg.add_answer(@instance, @srvttl, @rrsrv)
      amsg.add_additional(*@hostrr) if @hostrr
 
    when IN::TXT.object_id
      amsg.add_question(name, rtype)
      amsg.add_answer(@instance, @srvttl, @rrtxt)
    end

  when @type
    # See [DNSSD:14.1]
    case rtype.object_id
    when IN::ANY.object_id, IN::PTR.object_id
      amsg.add_question(name, rtype)
      amsg.add_answer(@type,     @ptrttl, @rrptr)
      amsg.add_additional(@instance, @srvttl, @rrsrv)
      amsg.add_additional(@instance, @srvttl, @rrtxt)
      amsg.add_additional(*@hostrr) if @hostrr
    end

  when @enum
    case rtype.object_id
    when IN::ANY.object_id, IN::PTR.object_id
      amsg.add_question(name, rtype)
      amsg.add_answer(@type, @ptrttl, @rrenum)
    end

  end
end

#domain=(domain) ⇒ Object

Default - .local



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# File 'lib/net/dns/mdns.rb', line 1038

def domain=(domain)
  @domain = DNS::Name.create(domain.to_str)
end

#inspect ⇒ Object 



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# File 'lib/net/dns/mdns.rb', line 1050

def inspect
  "#<#{self.class}: #{@instance} is #{@target}:#{@port}>"
end

#priority=(secs) ⇒ Object

Default - 0



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# File 'lib/net/dns/mdns.rb', line 1030

def priority=(secs)
  @priority = secs.to_int
end

#start ⇒ Object 



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# File 'lib/net/dns/mdns.rb', line 1106

def start
  Responder.instance.service_start(self, [
       [@type, @ptrttl, @rrptr],
       [@instance, @srvttl, @rrsrv],
       [@instance, @srvttl, @rrtxt],
       @hostrr
    ].compact)
  self
end

#stop ⇒ Object 



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# File 'lib/net/dns/mdns.rb', line 1116

def stop
  Responder.instance.service_stop(self)
  self
end

#to_s ⇒ Object 



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# File 'lib/net/dns/mdns.rb', line 1046

def to_s
  "MDNS::Service: #{@instance} is #{@target}:#{@port}>"
end

#ttl=(secs) ⇒ Object

Default - 7 days



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# File 'lib/net/dns/mdns.rb', line 1026

def ttl=(secs)
  @ttl = secs.to_int
end

#weight=(secs) ⇒ Object

Default - 0



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# File 'lib/net/dns/mdns.rb', line 1034

def weight=(secs)
  @weight = secs.to_int
end