Class: Ext3::Inode

Inherits:
Object
  • Object
show all
Defined in:
lib/fs/ext3/inode.rb

Overview

//////////////////////////////////////////////////////////////////////////// // Class.

Constant Summary collapse

PF_O_EXECUTE =

Bits 0 to 8 of file mode.

0x0001
PF_O_WRITE =

owner execute

0x0002
PF_O_READ =

owner write

0x0004
PF_G_EXECUTE =

owner read

0x0008
PF_G_WRITE =

group execute

0x0010
PF_G_READ =

group write

0x0020
PF_U_EXECUTE =

group read

0x0040
PF_U_WRITE =

user execute

0x0080
PF_U_READ =

user write

0x0100
MSK_PERM_OWNER =

For accessor convenience.

(PF_O_EXECUTE | PF_O_WRITE | PF_O_READ)
MSK_PERM_GROUP = 
(PF_G_EXECUTE | PF_G_WRITE | PF_G_READ)
MSK_PERM_USER = 
(PF_U_EXECUTE | PF_U_WRITE | PF_U_READ)
DF_STICKY =

Bits 9 to 11 of file mode.

0x0200
DF_SET_GID = 
0x0400
DF_SET_UID = 
0x0800
FM_FIFO =

Bits 12 to 15 of file mode.

0x1000
FM_CHAR =

fifo device (pipe)

0x2000
FM_DIRECTORY =

char device

0x4000
FM_BLOCK_DEV =

directory

0x6000
FM_FILE =

block device

0x8000
FM_SYM_LNK =

regular file

0xa000
FM_SOCKET =

symbolic link

0xc000
MSK_FILE_MODE =

For accessor convenience.

0xf000
MSK_IS_DEV = 
(FM_FIFO | FM_CHAR | FM_BLOCK_DEV | FM_SOCKET)
IF_SECURE_DEL =

Inode flags.

0x00000001
IF_KEEP_COPY =

wipe when deleting

0x00000002
IF_COMPRESS =

never delete

0x00000004
IF_SYNCHRO =

compress content

0x00000008
IF_IMMUTABLE =

don’t cache

0x00000010
IF_APPEND =

file cannot change

0x00000020
IF_NO_DUMP =

always append

0x00000040
IF_NO_ATIME =

don’t cat

0x00000080
IF_HASH_INDEX =

don’t update atime

0x00001000
IF_JOURNAL =

if dir, has hash index

0x00002000
@@FM2FT =

Lookup table for File Mode to File Type.

{
  Inode::FM_FIFO      => DirectoryEntry::FT_FIFO,
  Inode::FM_CHAR      => DirectoryEntry::FT_CHAR,
  Inode::FM_DIRECTORY => DirectoryEntry::FT_DIRECTORY,
  Inode::FM_BLOCK_DEV => DirectoryEntry::FT_BLOCK,
  Inode::FM_FILE      => DirectoryEntry::FT_FILE,
  Inode::FM_SYM_LNK   => DirectoryEntry::FT_SYM_LNK,
  Inode::FM_SOCKET    => DirectoryEntry::FT_SOCKET
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(buf) ⇒ Inode

Returns a new instance of Inode.



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# File 'lib/fs/ext3/inode.rb', line 106

def initialize(buf)
  raise "Ext3::Inode.initialize: Nil buffer" if buf.nil?
  @in = INODE.decode(buf)

  @mode    = @in['file_mode']
  @flags   = @in['flags']
  @length  = @in['size_lo']
  @length += (@in['size_hi'] << 32) unless self.isDir?

  # NOTE: Unpack the direct block pointers separately.
  @blockPointers      = @in['blk_ptrs'].unpack('L12')
  @sngIndBlockPointer = @in['ind_ptr']
  @dblIndBlockPointer = @in['dbl_ind_ptr']
  @tplIndBlockPointer = @in['tpl_ind_ptr']

  # If this is a symlnk < 60 bytes, grab the link metadata.
  if self.isSymLink? && length < SYM_LNK_SIZE
    @symlnk = buf[SYM_LNK_OFFSET, SYM_LNK_SIZE]
    # rPath is a wildcard. Sometimes they allocate when length < SYM_LNK_SIZE.
    # Analyze each byte of the first block pointer & see if it makes sense as ASCII.
    @symlnk[0, 4].each_byte do |c|
      if !(c > 45 && c < 48) && !((c > 64 && c < 91) || (c > 96 && c < 123))
        # This seems to be a block pointer, so nix @symlnk & pretend it's a regular file.
        @symlnk = nil
        break
      end
    end
  end
end

Instance Attribute Details

#blockPointers ⇒ Object (readonly)

Returns the value of attribute blockPointers.



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# File 'lib/fs/ext3/inode.rb', line 103

def blockPointers
  @blockPointers
end

#dblIndBlockPointer ⇒ Object (readonly)

Returns the value of attribute dblIndBlockPointer.



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# File 'lib/fs/ext3/inode.rb', line 104

def dblIndBlockPointer
  @dblIndBlockPointer
end

#flags ⇒ Object (readonly)

Returns the value of attribute flags.



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# File 'lib/fs/ext3/inode.rb', line 103

def flags
  @flags
end

#length ⇒ Object (readonly)

Returns the value of attribute length.



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# File 'lib/fs/ext3/inode.rb', line 103

def length
  @length
end

#mode ⇒ Object (readonly)

Returns the value of attribute mode.



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# File 'lib/fs/ext3/inode.rb', line 103

def mode
  @mode
end

#sngIndBlockPointer ⇒ Object (readonly)

Returns the value of attribute sngIndBlockPointer.



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# File 'lib/fs/ext3/inode.rb', line 104

def sngIndBlockPointer
  @sngIndBlockPointer
end

#symlnk ⇒ Object (readonly)

Returns the value of attribute symlnk.



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# File 'lib/fs/ext3/inode.rb', line 103

def symlnk
  @symlnk
end

#tplIndBlockPointer ⇒ Object (readonly)

Returns the value of attribute tplIndBlockPointer.



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# File 'lib/fs/ext3/inode.rb', line 104

def tplIndBlockPointer
  @tplIndBlockPointer
end

Instance Method Details

#aTime ⇒ Object 



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# File 'lib/fs/ext3/inode.rb', line 159

def aTime
  Time.at(@in['atime'])
end

#cTime ⇒ Object 



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# File 'lib/fs/ext3/inode.rb', line 163

def cTime
  Time.at(@in['ctime'])
end

#dTime ⇒ Object 



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# File 'lib/fs/ext3/inode.rb', line 171

def dTime
  Time.at(@in['dtime'])
end

#dump ⇒ Object 



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# File 'lib/fs/ext3/inode.rb', line 202

def dump
  out = "\#<#{self.class}:0x#{'%08x' % object_id}>\n"
  out += "File mode    : 0x#{'%04x' % @in['file_mode']}\n"
  out += "UID          : #{uid}\n"
  out += "Size         : #{length}\n"
  out += "ATime        : #{aTime}\n"
  out += "CTime        : #{cTime}\n"
  out += "MTime        : #{mTime}\n"
  out += "DTime        : #{dTime}\n"
  out += "GID          : #{gid}\n"
  out += "Link count   : #{@in['link_count']}\n"
  out += "Sector count : #{@in['sector_count']}\n"
  out += "Flags        : 0x#{'%08x' % @in['flags']}\n"
  out += "Direct block pointers:\n"
  12.times { |i| p = @blockPointers[i]; out += "  #{i} = 0x#{'%08x' % p}\n" }
  out += "Sng Indirect : 0x#{'%08x' % @in['ind_ptr']}\n"
  out += "Dbl Indirect : 0x#{'%08x' % @in['dbl_ind_ptr']}\n"
  out += "Tpl Indirect : 0x#{'%08x' % @in['tpl_ind_ptr']}\n"
  out += "Generation   : 0x#{'%08x' % @in['gen_num']}\n"
  out += "Ext attrib   : 0x#{'%08x' % @in['ext_attrib']}\n"
  out += "Frag blk adrs: 0x#{'%08x' % @in['frag_blk']}\n"
  out += "Frag index   : 0x#{'%02x' % @in['frag_idx']}\n"
  out += "Frag size    : 0x#{'%02x' % @in['frag_siz']}\n"
  out
end

#fileModeToFileType ⇒ Object

//////////////////////////////////////////////////////////////////////////// // Utility functions.



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# File 'lib/fs/ext3/inode.rb', line 198

def fileModeToFileType
  @@FM2FT[@mode & MSK_FILE_MODE]
end

#gid ⇒ Object 



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# File 'lib/fs/ext3/inode.rb', line 175

def gid
  (@in['gid_hi'] << 16) | @in['gid_lo']
end

#groupPermissions ⇒ Object 



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# File 'lib/fs/ext3/inode.rb', line 187

def groupPermissions
  @in['file_mode'] & MSK_PERM_GROUP
end

#isDev? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fs/ext3/inode.rb', line 151

def isDev?
  @mode & MSK_IS_DEV > 0
end

#isDir? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fs/ext3/inode.rb', line 143

def isDir?
  @mode & FM_DIRECTORY == FM_DIRECTORY
end

#isFile? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fs/ext3/inode.rb', line 147

def isFile?
  @mode & FM_FILE == FM_FILE
end

#isSymLink? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fs/ext3/inode.rb', line 155

def isSymLink?
  @mode & FM_SYM_LNK == FM_SYM_LNK
end

#mTime ⇒ Object 



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# File 'lib/fs/ext3/inode.rb', line 167

def mTime
  Time.at(@in['mtime'])
end

#ownerPermissions ⇒ Object 



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# File 'lib/fs/ext3/inode.rb', line 183

def ownerPermissions
  @in['file_mode'] & MSK_PERM_OWNER
end

#permissions ⇒ Object 



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# File 'lib/fs/ext3/inode.rb', line 179

def permissions
  @in['file_mode'] & (MSK_PERM_OWNER | MSK_PERM_GROUP | MSK_PERM_USER)
end

#uid ⇒ Object

//////////////////////////////////////////////////////////////////////////// // Class helpers & accessors.



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# File 'lib/fs/ext3/inode.rb', line 139

def uid
  (@in['uid_hi'] << 16) | @in['uid_lo']
end

#userPermissions ⇒ Object 



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# File 'lib/fs/ext3/inode.rb', line 191

def userPermissions
  @in['file_mode'] & MSK_PERM_USER
end