Class: Resolv::DNS::Message

Inherits:
Object
  • Object
show all
Defined in:
lib/net/dns/resolv.rb,
lib/net/dns/resolvx.rb

Overview

:nodoc:

Defined Under Namespace

Classes: MessageDecoder, MessageEncoder

Constant Summary collapse

@@identifier = 
-1

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(id = (@@identifier += 1) & 0xffff) ⇒ Message

Returns a new instance of Message.



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# File 'lib/net/dns/resolv.rb', line 1130

def initialize(id = (@@identifier += 1) & 0xffff)
  @id = id
  @qr = 0
  @opcode = 0
  @aa = 0
  @tc = 0
  @rd = 0 # recursion desired
  @ra = 0 # recursion available
  @rcode = 0
  @question = []
  @answer = []
  @authority = []
  @additional = []
end

Instance Attribute Details

#aa ⇒ Object

Returns the value of attribute aa.



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# File 'lib/net/dns/resolv.rb', line 1145

def aa
  @aa
end

#additional ⇒ Object (readonly)

Returns the value of attribute additional.



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# File 'lib/net/dns/resolv.rb', line 1146

def additional
  @additional
end

#answer ⇒ Object (readonly)

Returns the value of attribute answer.



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# File 'lib/net/dns/resolv.rb', line 1146

def answer
  @answer
end

#authority ⇒ Object (readonly)

Returns the value of attribute authority.



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# File 'lib/net/dns/resolv.rb', line 1146

def authority
  @authority
end

#id ⇒ Object

Returns the value of attribute id.



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# File 'lib/net/dns/resolv.rb', line 1145

def id
  @id
end

#opcode ⇒ Object

Returns the value of attribute opcode.



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# File 'lib/net/dns/resolv.rb', line 1145

def opcode
  @opcode
end

#qr ⇒ Object

Returns the value of attribute qr.



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# File 'lib/net/dns/resolv.rb', line 1145

def qr
  @qr
end

#question ⇒ Object (readonly)

Returns the value of attribute question.



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# File 'lib/net/dns/resolv.rb', line 1146

def question
  @question
end

#ra ⇒ Object

Returns the value of attribute ra.



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# File 'lib/net/dns/resolv.rb', line 1145

def ra
  @ra
end

#rcode ⇒ Object

Returns the value of attribute rcode.



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# File 'lib/net/dns/resolv.rb', line 1145

def rcode
  @rcode
end

#rd ⇒ Object

Returns the value of attribute rd.



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# File 'lib/net/dns/resolv.rb', line 1145

def rd
  @rd
end

#tc ⇒ Object

Returns the value of attribute tc.



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# File 'lib/net/dns/resolv.rb', line 1145

def tc
  @tc
end

Class Method Details

.decode(m) ⇒ Object 



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# File 'lib/net/dns/resolv.rb', line 1311

def Message.decode(m)
  o = Message.new(0)
  MessageDecoder.new(m) {|msg|
    id, flag, qdcount, ancount, nscount, arcount =
      msg.get_unpack('nnnnnn')
    o.id = id
    o.qr = (flag >> 15) & 1
    o.opcode = (flag >> 11) & 15
    o.aa = (flag >> 10) & 1
    o.tc = (flag >> 9) & 1
    o.rd = (flag >> 8) & 1
    o.ra = (flag >> 7) & 1
    o.rcode = flag & 15
    (1..qdcount).each {
      name, typeclass, unicast = msg.get_question
      o.add_question(name, typeclass, unicast)
    }
    (1..ancount).each {
      name, ttl, data, cacheflush = msg.get_rr
      o.add_answer(name, ttl, data)
    }
    (1..nscount).each {
      name, ttl, data = msg.get_rr
      o.add_authority(name, ttl, data)
    }
    (1..arcount).each {
      name, ttl, data = msg.get_rr
      o.add_additional(name, ttl, data)
    }
  }
  return o
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/net/dns/resolv.rb', line 1148

def ==(other)
  return @id == other.id &&
         @qr == other.qr &&
         @opcode == other.opcode &&
         @aa == other.aa &&
         @tc == other.tc &&
         @rd == other.rd &&
         @ra == other.ra &&
         @rcode == other.rcode &&
         @question == other.question &&
         @answer == other.answer &&
         @authority == other.authority &&
         @additional == other.additional
end

#add_additional(name, ttl, data) ⇒ Object 



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# File 'lib/net/dns/resolv.rb', line 1199

def add_additional(name, ttl, data)
  @additional << [Name.create(name), ttl, data]
end

#add_answer(name, ttl, data, cacheflush = false) ⇒ Object 



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# File 'lib/net/dns/resolv.rb', line 1176

def add_answer(name, ttl, data, cacheflush = false)
  @answer << [Name.create(name), ttl, data, cacheflush]
end

#add_authority(name, ttl, data) ⇒ Object 



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# File 'lib/net/dns/resolv.rb', line 1189

def add_authority(name, ttl, data)
  @authority << [Name.create(name), ttl, data]
end

#add_question(name, typeclass, unicast = false) ⇒ Object 



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# File 'lib/net/dns/resolv.rb', line 1163

def add_question(name, typeclass, unicast = false)
  @question << [Name.create(name), typeclass, unicast]
end

#each_additional ⇒ Object 



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# File 'lib/net/dns/resolv.rb', line 1203

def each_additional
  @additional.each {|name, ttl, data|
    yield name, ttl, data
  }
end

#each_answer ⇒ Object

Can accept either |name, ttl, data| as block arguments (backwards-compatible/DNS-style), or |name, ttl, data, cacheflush| (mDNS-style).



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# File 'lib/net/dns/resolv.rb', line 1183

def each_answer # :yields: name, ttl, data, cacheflush
  @answer.each {|ary|
    yield ary
  }
end

#each_authority ⇒ Object 



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# File 'lib/net/dns/resolv.rb', line 1193

def each_authority
  @authority.each {|name, ttl, data|
    yield name, ttl, data
  }
end

#each_question ⇒ Object

Can accept either |name, typeclass| as block arguments (backwards-compatible/DNS-style), or |name, typeclass, unicast| (mDNS-style).



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# File 'lib/net/dns/resolv.rb', line 1170

def each_question # :yields: name, typeclass, unicast
  @question.each {|ary|
    yield ary
  }
end

#each_resource ⇒ Object 



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# File 'lib/net/dns/resolv.rb', line 1209

def each_resource
  each_answer {|name, ttl, data| yield name, ttl, data}
  each_authority {|name, ttl, data| yield name, ttl, data}
  each_additional {|name, ttl, data| yield name, ttl, data}
end

#encode ⇒ Object 



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# File 'lib/net/dns/resolv.rb', line 1215

def encode
  return MessageEncoder.new {|msg|
    msg.put_pack('nnnnnn',
      @id,
      (@qr & 1) << 15 |
      (@opcode & 15) << 11 |
      (@aa & 1) << 10 |
      (@tc & 1) << 9 |
      (@rd & 1) << 8 |
      (@ra & 1) << 7 |
      (@rcode & 15),
      @question.length,
      @answer.length,
      @authority.length,
      @additional.length)
    @question.each {|q|
      name, typeclass, unicast = q
      hibit = unicast ? (1<<15) : 0x00
      msg.put_name(name)
      msg.put_pack('nn', typeclass::TypeValue, typeclass::ClassValue|hibit)
    }
    [@answer, @authority, @additional].each {|rr|
      rr.each {|r|
        name, ttl, data, cacheflush = r
        hibit = cacheflush ? (1<<15) : 0x00
        msg.put_name(name)
        msg.put_pack('nnN', data.class::TypeValue, data.class::ClassValue|hibit, ttl)
        msg.put_length16 {data.encode_rdata(msg)}
      }
    }
  }.to_s
end

#query? ⇒ Boolean

Returns true if message is a query.

Returns:

  • (Boolean) 


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# File 'lib/net/dns/resolvx.rb', line 16

def query?
  qr == 0
end

#response? ⇒ Boolean

Returns true if message is a response.

Returns:

  • (Boolean) 


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# File 'lib/net/dns/resolvx.rb', line 21

def response?
  !query?
end