class Dnsruby::Header
The header portion of a DNS
packet
RFC 1035 Section 4.1.1
Constants
- MAX_ID
Attributes
Authoritative answer flag
The Authenticated Data flag Relevant in DNSSEC context. (The AD bit is only set on answers where signatures have been cryptographically verified or the server is authoritative for the data and is allowed to set the bit by policy.)
The number of records in the additional record section og the message
The number of records in the additional record section og the message
The number of records in the answer section of the message
The number of records in the additional record section og the message
The Checking Disabled flag
The header ID
The number of records in the authoriy section of the message
The header opcode
The number of records in the answer section of the message
The number of records in the answer section of the message
The number of records in the question section of the message
The query response flag
Recursion available flag
Recursion Desired flag
Truncated flag
The number of records in the authoriy section of the message
The number of records in the authoriy section of the message
The number of records in the question section of the message
The number of records in the question section of the message
Public Class Methods
# File lib/Dnsruby/message.rb, line 778 def Header.decrement_arcount_encoded(bytes) header = Header.new header_end = 0 MessageDecoder.new(bytes) {|msg| header.decode(msg) header_end = msg.index } header.arcount = header.arcount - 1 bytes[0,header_end]=MessageEncoder.new {|msg| header.encode(msg)}.to_s return bytes end
# File lib/Dnsruby/message.rb, line 718 def initialize(*args) if (args.length == 0) @id = rand(MAX_ID) @qr = false @opcode=OpCode.Query @aa = false @ad=false @tc = false @rd = false # recursion desired @ra = false # recursion available @cd=false @rcode=RCode.NoError @qdcount = 0 @nscount = 0 @ancount = 0 @arcount = 0 elsif (args.length == 1) decode(args[0]) end end
# File lib/Dnsruby/message.rb, line 747 def Header.new_from_data(data) header = Header.new MessageDecoder.new(data) {|msg| header.decode(msg)} return header end
Public Instance Methods
# File lib/Dnsruby/message.rb, line 791 def ==(other) return @qr == other.qr && @opcode == other.opcode && @aa == other.aa && @tc == other.tc && @rd == other.rd && @ra == other.ra && @cd == other.cd && @ad == other.ad && @rcode == other.get_header_rcode end
# File lib/Dnsruby/message.rb, line 754 def data return MessageEncoder.new {|msg| self.encode(msg) }.to_s end
# File lib/Dnsruby/message.rb, line 840 def decode(msg) @id, flag, @qdcount, @ancount, @nscount, @arcount = msg.get_unpack('nnnnnn') @qr = (((flag >> 15)&1)==1)?true:false @opcode = OpCode.new((flag >> 11) & 15) @aa = (((flag >> 10)&1)==1)?true:false @tc = (((flag >> 9)&1)==1)?true:false @rd = (((flag >> 8)&1)==1)?true:false @ra = (((flag >> 7)&1)==1)?true:false @ad = (((flag >> 5)&1)==1)?true:false @cd = (((flag >> 4)&1)==1)?true:false @rcode = RCode.new(flag & 15) end
# File lib/Dnsruby/message.rb, line 760 def encode(msg) msg.put_pack('nnnnnn', @id, (@qr ? 1:0) << 15 | (@opcode.code & 15) << 11 | (@aa ? 1:0) << 10 | (@tc ? 1:0) << 9 | (@rd ? 1:0) << 8 | (@ra ? 1:0) << 7 | (@ad ? 1:0) << 5 | (@cd ? 1:0) << 4 | (@rcode.code & 15), @qdcount, @ancount, @nscount, @arcount) end
This new get_header_rcode
method is intended for use only by the Message
class. This is because the Message
OPT section may contain an extended rcode (see RFC 2671 section 4.6). Using the header rcode only ignores this extension, and is not recommended.
# File lib/Dnsruby/message.rb, line 702 def get_header_rcode @rcode end
# File lib/Dnsruby/message.rb, line 739 def opcode=(op) @opcode = OpCode.new(op) end
# File lib/Dnsruby/message.rb, line 743 def rcode=(rcode) @rcode = RCode.new(rcode) end
# File lib/Dnsruby/message.rb, line 803 def to_s to_s_with_rcode(@rcode) end
# File lib/Dnsruby/message.rb, line 807 def to_s_with_rcode(rcode) retval = ";; id = #{@id}\n"; if (@opcode == OpCode::Update) retval += ";; qr = #{@qr} " +\ "opcode = #{@opcode.string} "+\ "rcode = #{@rcode.string}\n"; retval += ";; zocount = #{@qdcount} "+\ "prcount = #{@ancount} " +\ "upcount = #{@nscount} " +\ "adcount = #{@arcount}\n"; else retval += ";; qr = #{@qr} " +\ "opcode = #{@opcode.string} " +\ "aa = #{@aa} " +\ "tc = #{@tc} " +\ "rd = #{@rd}\n"; retval += ";; ra = #{@ra} " +\ "ad = #{@ad} " +\ "cd = #{@cd} " +\ "rcode = #{rcode.string}\n"; retval += ";; qdcount = #{@qdcount} " +\ "ancount = #{@ancount} " +\ "nscount = #{@nscount} " +\ "arcount = #{@arcount}\n"; end return retval; end