Class: DNSTraverse::Response

Inherits:
Object
  • Object
show all
Defined in:
lib/dnstraverse/response.rb

Overview

get a response to a query (or pass in the response if you already have one) creates lots of stats and info, caching as much as possible

Direct Known Subclasses

Loop, Maxdepth, NoGlue

Defined Under Namespace

Classes: Loop, Maxdepth, NoGlue

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(args) ⇒ Response

:qname, :qclass, :qtype, :ip, :bailiwick, optional :message



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# File 'lib/dnstraverse/response.rb', line 32

def initialize(args)
  dqc_args = { :qname => args[:qname], :qclass => args[:qclass],
    :qtype => args[:qtype], :ip => args[:ip],
    :bailiwick => args[:bailiwick], :message => args[:message] }
  @decoded_query = args[:decoded_query_cache].query(dqc_args)
  @server = args[:server]
  @infocache = InfoCache.new(args[:infocache]) # our infocache
  @starters = nil # initial servers for :referral/:restart
  @starters_bailiwick = nil # for initial servers for :referral/:restart
  @parent_ip = args[:parent_ip] # passed in in case we get referral_lame, for the key
  evaluate
  update_stats_key
  return self
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(key, *args, &block) ⇒ Object 



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# File 'lib/dnstraverse/response.rb', line 47

def method_missing(key, *args, &block)
  if @decoded_query.respond_to?(key) then
    return @decoded_query.send(key, *args)
  end
  super
end

Instance Attribute Details

#decoded_query ⇒ Object (readonly)

Returns the value of attribute decoded_query.



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# File 'lib/dnstraverse/response.rb', line 24

def decoded_query
  @decoded_query
end

#infocache ⇒ Object (readonly)

Returns the value of attribute infocache.



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# File 'lib/dnstraverse/response.rb', line 25

def infocache
  @infocache
end

#server ⇒ Object (readonly)

Returns the value of attribute server.



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# File 'lib/dnstraverse/response.rb', line 29

def server
  @server
end

#starters ⇒ Object (readonly)

:referral/:restart only



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# File 'lib/dnstraverse/response.rb', line 27

def starters
  @starters
end

#starters_bailiwick ⇒ Object (readonly)

:referral/:restart only



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# File 'lib/dnstraverse/response.rb', line 27

def starters_bailiwick
  @starters_bailiwick
end

#stats_key ⇒ Object (readonly)

Returns the value of attribute stats_key.



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# File 'lib/dnstraverse/response.rb', line 28

def stats_key
  @stats_key
end

#status ⇒ Object (readonly)

our status, expanding on DecodedQuery status



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# File 'lib/dnstraverse/response.rb', line 26

def status
  @status
end

Instance Method Details

#cleanup ⇒ Object

clean up the workings



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# File 'lib/dnstraverse/response.rb', line 68

def cleanup
  @infocache = nil
  ###@cacheable_good = @cacheable_bad = nil
  @starters = @starters_bailiwick = nil
  ###@auth_ns = @auth_soa = @auth_other = nil
end

#evaluate ⇒ Object

enrich the decoded_query to do the cache, lame checking and get starters



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# File 'lib/dnstraverse/response.rb', line 85

def evaluate
  @status = @decoded_query.status # use this as a base
  if @status != :exception
    # XXX order of cacheable_good is answer, authority, additional
    # perhaps we should add some checking for overlap between sections?
    @infocache.add(@decoded_query.cacheable_good)
  end
  case @decoded_query.status
  when :restart
    @starters, @starters_bailiwick = @infocache.get_startservers(@decoded_query.endname)
  when :referral
    @starters, @starters_bailiwick = @infocache.get_startservers(@decoded_query.endname)
    unless @decoded_query.bailiwick.nil? or @starters_bailiwick =~ /\.#{@decoded_query.bailiwick}$/i
      @status = :referral_lame
    end
    starternames = @starters.map { |x| x[:name].to_s.downcase }
    if starternames.sort != @decoded_query.authoritynames.sort
      @decoded_query.warnings_add "Referred authority names do not match query cache expectations"
    end
  end
end

#inside_bailiwick?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dnstraverse/response.rb', line 75

def inside_bailiwick?(name)
  return true if @bailiwick.nil?
  bwend = ".#{@bailiwick}"
  namestr = name.to_s
  return true if namestr.casecmp(@bailiwick) == 0
  return true if namestr =~ /#{bwend}$/i
  return false
end

#to_s ⇒ Object

convert to string - check for our enrichments, or use decoded_status



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# File 'lib/dnstraverse/response.rb', line 108

def to_s
  case @status
    when :referral_lame
    return "Lame referral to #{@decoded_query.authoritynames}"
  else
    return @decoded_query.to_s
  end
end

#update_stats_key ⇒ Object

set the statistics key - this is used to decide when to merge statistics together. the same key = merge, different key = keep separate this is why exception name/message is added for exception types



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# File 'lib/dnstraverse/response.rb', line 57

def update_stats_key
  r = @decoded_query
  @stats_key = "key:#{@status}:#{r.ip}:#{@server}:#{r.qname}:#{r.qclass}:#{r.qtype}"
  if @status == :exception and r.message.is_a? Exception then
    @stats_key+= ":#{r.message}"
  elsif @status == :referral_lame then
    @stats_key+= ":#{@parent_ip}"
  end
end