Module: Scriptroute::Tulip::LangChecker

Defined in:
lib/scriptroute/tulip/helper.rb

Overview

whether a given IP speaks a particular language ##########

Class Method Summary collapse

Class Method Details

.getBestOption(destination, *prefList) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 7

def LangChecker.getBestOption(destination, *prefList)
  prefList.each { |type| 
    case type
    when "tstamp"
      return "tstamp" if(LangChecker.probeResponse(destination, 
                                                   Scriptroute::ICMP::ICMP_TSTAMP, 
                                                   Scriptroute::ICMP::ICMP_TSTAMPREPLY)) 
    when "echo"
      return "echo" if(LangChecker.probeResponse(destination, 
                                                 Scriptroute::ICMP::ICMP_ECHO, 
                                                 Scriptroute::ICMP::ICMP_ECHOREPLY))
    when "udp"
      return "udp" if(LangChecker.udp(destination))
    when "tcp" 
      return "tcp" if(LangChecker.tcp(destination))
    else
      raise("ERROR: unknown packet type = #{type}");
    end
  }
  return nil;
end

.getBestOption4IPIDs(destination, *prefList) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 29

def LangChecker.getBestOption4IPIDs(destination, *prefList)
  prefList.each { |type| 
    return [type, true] if(LangChecker.increasingIPIDs(destination, 255, type));
  }	
  return [nil, false];
end

.getBestPathOption4IPIDs(destination, ttl, router, tpath) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 163

def LangChecker.getBestPathOption4IPIDs(destination, ttl, router, tpath)
  canCheckForward = (LangChecker.increasingIPIDs(destination, ttl, "udp"))? 1 : -1;
  #puts "ccf = #{canCheckForward}\n";
  if (canCheckForward == -1) then
    ##todo: can be extended to other types, such as timestamps
    if (LangChecker.increasingIPIDs(router, 255, "echo")) then  
	subpath = TracePath.new(router);
	puts "subpathto #{router}:\n#{subpath.to_s}\n";
	if (tpath.subset(subpath)) then
 return [router, 255, "echo", 1];	  
	end
    end
  end
  ## the default
  return [destination, ttl, "udp", canCheckForward];
end

.getDefaultPacket(type, seq = 0) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 142

def LangChecker.getDefaultPacket(type, seq=0) 
  if (type == "udp") 
    return Scriptroute::UDP.new(12);
  elsif (type == "tcp") 
    probe = Scriptroute::TCP.new(0);
    probe.th_dport=80;
    probe.th_win=1024;
    return probe;
  else 
    probe = if (type == "echo")
              Scriptroute::ICMPecho.new(0)
            elsif (type == "tstamp")
              Scriptroute::ICMPtstamp.new(0)
            else 
              raise "ERROR: unsupported packettype #{type} in sendAndReceiveTrain\n";
            end
    probe.icmp_seq=seq;
    return probe;
  end
end

.increasingIPIDs(destination, ttl, type) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 82

def LangChecker.increasingIPIDs(destination, ttl, type)     
  #puts "lchecker: increasing ip-ids #{destination} #{ttl} #{type}";
  delayedArray = Array.new();
  (0..2).each { |i|
    probe = LangChecker.getDefaultPacket(type, i);
    probe.ip_dst = destination;
    probe.ip_ttl = ttl;
    delayedArray.push(Struct::DelayedPacket.new(0.001, probe));
  }
  begin
    packets = Scriptroute::send_train(delayedArray);
  rescue Exception => e
    $stderr.puts "Exception #{e} sending:"
    delayedArray.each_with_index { |dp,i| $stderr.puts "%d: %s" % [ i, dp.packet.to_s ] }
    return false
  end
  
  if (!packets[0] || !packets[1] || !packets[2] || 
                   !packets[0].response || !packets[1].response || !packets[2].response)
    return false;
  end
  
#      puts "%s (ttl=%d, %s): %s %s %s  --> %d %d %d" % [destination, ttl, type,
#        packets[0].response.packet.ip_src, 
#        packets[1].response.packet.ip_src, 
#        packets[2].response.packet.ip_src, 
#        packets[0].response.packet.ip_id,
#        packets[1].response.packet.ip_id,
#        packets[2].response.packet.ip_id];

#     puts "%.3f %.3f %.3f" % [packets[0].probe.time.to_f*1000, 
#      packets[1].probe.time.to_f*1000, 
#      packets[2].probe.time.to_f*1000];


  ##zeroes are being returned
  return false if (packets[0].response.packet.ip_id == 0 && packets[1].response.packet.ip_id == 0);
  
  ##the remote destination is copying my id's
  return false if (packets[0].response.packet.ip_id == packets[0].probe.packet.ip_id &&
     packets[1].response.packet.ip_id == packets[1].probe.packet.ip_id);
  
  #puts "passed zero and copy test\n";

  #    packets.sort! { |a,b| a.probe.time <=> b.probe.time };
  ids = packets.map { |p| p.response.packet.ip_id };
  
  return true if (AliasResolution.before(ids[0]-10, ids[1]) && 
    AliasResolution.before(ids[1], ids[0]+200) && 
    ids[0] != ids[1] &&
    AliasResolution.before(ids[1]-10, ids[2]) && 
    AliasResolution.before(ids[2], ids[1]+200) && 
    ids[1] != ids[2]);

  #puts "failed maternity test with #{ids.join(" ")}\n";

  return false;

end

.probeResponse(destination, probeType, responseType) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 37

def LangChecker.probeResponse(destination, probeType, responseType)
  probe = Scriptroute::ICMP.new(0);
  probe.ip_dst = destination;
  probe.icmp_type = probeType;
  probe.icmp_code = 0;
  probe.icmp_seq = 0;
  packets = Scriptroute::send_train([Struct::DelayedPacket.new(0, probe)]);
  return false if (!packets[0].response);
  response = packets[0].response.packet;
  if (response.is_a?(Scriptroute::ICMP) && 
	response.icmp_type == responseType) 
    return true;
  end
  return false;
end

.tcp(destination) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 72

def LangChecker.tcp(destination)
  probe = Scriptroute::TCP.new(12) 
  probe.ip_dst = destination;
  packets = Scriptroute::send_train([Struct::DelayedPacket.new(0, probe)]);
  return false if (!packets[0].response);
  response = packets[0].response.packet;
  puts response
  return (response.is_a?(Scriptroute::TCP) && response.flag_rst)
end

.udp(destination) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 53

def LangChecker.udp(destination)
  probe = Scriptroute::UDP.new(12) 
  probe.ip_dst = destination;
  begin 
    packets = Scriptroute::send_train([Struct::DelayedPacket.new(0, probe)]);
  rescue Exception => e
    puts "sluffing exception" + e
    return false
  end
  return false if (!packets[0].response);
  response = packets[0].response.packet;
  if (response.is_a?(Scriptroute::ICMP) &&
	response.icmp_type == Scriptroute::ICMP::ICMP_UNREACH &&
	response.icmp_code == Scriptroute::ICMP::ICMP_UNREACH_PORT )
    return true;
  end
  return false;
end