Class: Scriptroute::Tulip::TracePath

Inherits:
Object
  • Object
show all
Defined in:
lib/scriptroute/tulip/helper.rb

Overview

the traceroute path ############

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(dst, resolveNames = false, start_ttl = 1, end_ttl = 30) ⇒ TracePath

Returns a new instance of TracePath.



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# File 'lib/scriptroute/tulip/helper.rb', line 618

def initialize (dst, resolveNames=false, start_ttl=1, end_ttl=30)
  @path = Array.new;
  @dst = dst;
  @speaks_udp = (LangChecker.udp(@dst)) ? true : false;
  @status_code = "incomplete";

  #make self as first hop; simplifies binary search.
  @path.push(TraceHop.new(0, "0", dst));

  probe = Scriptroute::UDP.new(12)
  probe.ip_dst = dst
  port_unreach = false

  catch :port_unreachable do 
    (start_ttl..end_ttl).each { |ttl|
	probe.ip_ttl = ttl
	#puts "before trace: %.3f" % [Time.now.to_f];
	packets = Scriptroute::send_train([ Struct::DelayedPacket.new(0, probe) ]);
	#puts "after trace: %.3f" % [Time.now.to_f];
	if (!packets[0]) then 
 STDERR.puts("WARNING: scriptrouted err'd. sleeping and retrying"); 
 Kernel::sleep(5); 
 redo; 
	end;
	response = (packets[0].response) ?  packets[0].response.packet : nil
	if (response.is_a?(Scriptroute::ICMP)) then
 name = response.ip_src;
 if (resolveNames) then
   begin 
     name = Socket.gethostbyname(response.ip_src)[0];
   rescue 
   end
 end
 @path.push(TraceHop.new(ttl, response.ip_src, dst, name)) if (!containsIP(response.ip_src));
 port_unreach = true if (response.icmp_type == 3)
 @status_code = "complete" if (response.icmp_type == 3 && response.icmp_code == 3) 
	else
 port_unreach = true if (ttl - @path.last.hop >=2 and !@speaks_udp);
	end
	throw :port_unreachable if(port_unreach)
    }
  end
  
end

Instance Attribute Details

#dst ⇒ Object (readonly)

Returns the value of attribute dst.



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# File 'lib/scriptroute/tulip/helper.rb', line 616

def dst
  @dst
end

#path ⇒ Object (readonly)

Returns the value of attribute path.



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# File 'lib/scriptroute/tulip/helper.rb', line 616

def path
  @path
end

#speaks_udp ⇒ Object (readonly)

Returns the value of attribute speaks_udp.



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# File 'lib/scriptroute/tulip/helper.rb', line 616

def speaks_udp
  @speaks_udp
end

#status_code ⇒ Object (readonly)

Returns the value of attribute status_code.



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# File 'lib/scriptroute/tulip/helper.rb', line 616

def status_code
  @status_code
end

Instance Method Details

#checkValidAnchors(farindex, farpath, nearindex, nearpath, verbose = true) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 709

def checkValidAnchors(farindex, farpath, nearindex, nearpath, verbose=true) 
  return (farpath.subset(nearpath) and subset(farpath, path[nearindex].hop));     
end

#containsIP(ip) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 663

def containsIP(ip) 
  @path[1..-1].map { |p| return true if (p.ip == ip) };
  return false;
end

#getClosestTSNode(starthop, delta, minhop, maxhop) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 668

def getClosestTSNode(starthop, delta, minhop, maxhop) 
 while (starthop >= minhop && starthop <= maxhop) 
   if LangChecker.probeResponse(@path[starthop].ip, 
		   Scriptroute::ICMP::ICMP_TSTAMP, 
		   Scriptroute::ICMP::ICMP_TSTAMPREPLY) then
      return starthop;
    end
    starthop += delta;
  end
  return nil;
end

#getIndex(ip) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 713

def getIndex(ip)
  (1..@path.length-1).each { |i|
    if (@path[i].ip == ip) 
	 return i;
    end
  }
  return -1;
end

#subset(another, minhop = 1) ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 680

def subset (another, minhop = 1) 
  lasthop = another.path.last.hop;
  matches = Array.new();
  mismatches = Array.new();
  empties = Array.new();
  (minhop..lasthop).each { |hop|
    myhop = @path[hop];
    hishop = another.path[hop];
    if (myhop and hishop) 
	 (myhop == hishop)? matches.push(hop) : mismatches.push(hop);
    elsif (myhop or hishop) 
	 empties.push(hop);
    end
  }
  lastMatch = true;
  if (another.status_code == "incomplete")
    index = getIndex(another.dst);
    if (index < 0 or lasthop + 1 < index) then
	 lastMatch = false;
    end
  end

  #puts "subset results. matches: #{matches.join(" ")} mismatches: #{mismatches.join(" ")} empties: #{empties.join(" ")} lastMatch: #{lastMatch}";

  return true if ((mismatches.length == 0 or mismatches.last <= $prefixpath) && ##let go for local load balancing
    lastMatch and matches.index(lasthop));   ##the last hop has to match
  return false;
end

#to_s ⇒ Object 



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# File 'lib/scriptroute/tulip/helper.rb', line 722

def to_s 
  @path[1..-1].map { |p| p.to_s }.join("\n");
end