Class: Syspy::TdsPackageStream

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

Constant Summary collapse

HEADER_LENGTH = 
45
HEADER_REGEXP = 
/\d{3}\.\d{3}\.\d{3}\.\d{3}\.\d{5}-\d{3}\.\d{3}\.\d{3}\.\d{3}\.\d{5}: /

Instance Method Summary collapse

Constructor Details

#initialize(interface, dst, dst_port) ⇒ TdsPackageStream

Returns a new instance of TdsPackageStream.



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# File 'lib/tds_package_stream.rb', line 14

def initialize(interface,dst,dst_port)
  @interface = interface
  @dst = dst
  @dst_port = dst_port
  @in,@out = IO.pipe()
end

Instance Method Details

#each_package ⇒ Object 



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# File 'lib/tds_package_stream.rb', line 21

def each_package()
  Thread.abort_on_exception = true       
  @tcpdump_thread = Thread.new(){             
    IO.popen("#{File.dirname(__FILE__)}/tcpflow -c -B -i #{@interface} tcp and dst #{@dst} and dst port #{@dst_port} 2>/dev/null"){|io|         
      content = ""
      loop(){           
        content << io.read(1)
        
        if(content.match(HEADER_REGEXP))                           
          payload = content[0..(-2 - HEADER_LENGTH)]
          @out.write(payload)
          @out.flush
          content = ""
        end
       
        Log.debug "Network package done"      
      }
    } 
  }  

  content = ""
  @in.each_byte(){|byte|
    if(byte == 0x0F)                 
      last_packet_indicator = Bytes.uint(@in)          
      length = Bytes.uint16be(@in)
       
      # skip next 4 bytes of the header
      if(Bytes.uint32be(@in) == 0x00)
        content << @in.read(length - 8)
        
        if(last_packet_indicator == 0x1)              
          begin
            io = StringIO.new(content)
            package = handle_package(io)
            yield package if package               
          ensure
            content = ""
          end             
        end
      end
    end           
  }     
end

#handle_package(io) ⇒ Object 



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# File 'lib/tds_package_stream.rb', line 65

def handle_package(io)    
  token = Bytes.uint(io)
  token_class = TdsTokens.token_class(token)
  if(token_class)
    length = TdsTokens.fixed_length(token)
    unless(length)
      length_field_size = TdsTokens.length_field_size(token)
      if(length_field_size)
        length = Bytes.uintle(io,length_field_size)
      end       
    end
    Log.debug("Got #{TdsTokens.token_name(token)} of #{length} bytes")
    package = token_class.new(io,length)
    return package        
  end
  nil   
end