Module: VMWareDiskProbe

Defined in:
lib/disk/modules/VMWareDiskProbe.rb

Constant Summary collapse

SPARSE_MAGIC = 
"KDMV"
SPARSE_MOD = 
"VMWareSparseDisk"
COWD_MAGIC = 
"COWD"
COWD_MOD = 
"VMWareCowdDisk"
DESC_MOD = 
"VMWareDescriptor"

Class Method Summary collapse

Class Method Details

.binary_data?(str) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/disk/modules/VMWareDiskProbe.rb', line 70

def self.binary_data?(str)
  return false if str.nil? || str.empty?
  return (str.count("^ -~", "^\r\n") / str.size > 0.3 || str.count("\x00") > 0) unless str.empty?
end

.getDescriptor(ofs, siz, ostruct) ⇒ Object 



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# File 'lib/disk/modules/VMWareDiskProbe.rb', line 59

def self.getDescriptor(ofs, siz, ostruct)
  f = File.open(ostruct.fileName, "rb")
  f.seek(ofs * 512, IO::SEEK_SET)
  desc = f.read(siz * 512)
  f.close

  pos  = desc.index("\000")
  desc = desc[0...pos] unless pos.nil?
  ostruct.Descriptor = desc
end

.probe(ostruct) ⇒ Object 



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# File 'lib/disk/modules/VMWareDiskProbe.rb', line 10

def self.probe(ostruct)
  return nil unless ostruct.fileName
  # If not .vmdk then not VMWare.
  # Allow .miq also.
  ext = File.extname(ostruct.fileName).downcase
  return nil if ext != ".vmdk" && ext != ".miq"

  size  = File.size(ostruct.fileName)
  f     = File.new(ostruct.fileName, "rb")
  magic = f.read(4)

  if magic == SPARSE_MAGIC
    # get descriptor offset & size.
    f.seek(24, IO::SEEK_CUR)
    ofs = f.read(8).unpack("Q")[0]
    siz = f.read(8).unpack("Q")[0]
  end

  binary = false
  if (magic != SPARSE_MAGIC) && (magic != COWD_MAGIC)
    f.rewind
    loop do
      data   = f.read(4096)
      break if data.nil?
      binary = binary_data?(data)
      break if binary
    end
  end

  f.close

  return COWD_MOD if magic == COWD_MAGIC

  if magic == SPARSE_MAGIC
    # If this ostruct already has a descriptor don't bother checking.
    # NOTE: If it does have a descriptor, we're coming from VMWareDescriptor.rb
    #       trying to open a disk - so don't regress infinitely.
    if ostruct.Descriptor.nil? && ofs > 0
      getDescriptor(ofs, siz, ostruct) if ofs > 0
      return DESC_MOD
    end

    return SPARSE_MOD
  end

  return false if binary
  DESC_MOD
end