def _rr_new(self, rr_version, rr_name, rr_symlink_target,
rr_relocated_child, rr_relocated, rr_relocated_parent,
file_mode):
'''
Internal method to add Rock Ridge to a Directory Record.
Parameters:
rr_version - A string containing the version of Rock Ridge to use for
this record.
rr_name - The Rock Ridge name to associate with this directory record.
rr_symlink_target - The target for the symlink, if this is a symlink
record (otherwise, None).
rr_relocated_child - True if this is a directory record for a rock
ridge relocated child.
rr_relocated - True if this is a directory record for a relocated
entry.
rr_relocated_parent - True if this is a directory record for a rock
ridge relocated parent.
file_mode - The Unix file mode for this Rock Ridge entry.
Returns:
Nothing.
'''
self.rock_ridge = rockridge.RockRidge()
is_first_dir_record_of_root = self.file_ident == b'\x00' and self.parent.parent is None
bytes_to_skip = 0
if self.xa_record is not None:
bytes_to_skip = XARecord.length()
self.dr_len = self.rock_ridge.new(is_first_dir_record_of_root, rr_name,
file_mode, rr_symlink_target,
rr_version, rr_relocated_child,
rr_relocated, rr_relocated_parent,
bytes_to_skip, self.dr_len)
if self.isdir:
if self.parent.parent is not None:
if self.file_ident == b'\x00':
self.parent.rock_ridge.add_to_file_links()
self.rock_ridge.add_to_file_links()
elif self.file_ident == b'\x01':
self.rock_ridge.copy_file_links(
self.parent.parent.children[1].rock_ridge)
else:
self.parent.rock_ridge.add_to_file_links()
self.parent.children[0].rock_ridge.add_to_file_links()
else:
if self.file_ident != b'\x00' and self.file_ident != b'\x01':
self.parent.children[0].rock_ridge.add_to_file_links()
self.parent.children[1].rock_ridge.add_to_file_links()
else:
self.rock_ridge.add_to_file_links()
def parse(self, vd, record, parent):
'''
Parse a directory record out of a string.
Parameters:
vd - The Volume Descriptor this record is part of.
record - The string to parse for this record.
parent - The parent of this record.
Returns:
True if this Directory Record has Rock Ridge extensions, False otherwise.
'''
if self._initialized:
raise pycdlibexception.PyCdlibInternalError(
'Directory Record already initialized')
if len(record) > 255:
# Since the length is supposed to be 8 bits, this should never
# happen.
raise pycdlibexception.PyCdlibInvalidISO(
'Directory record longer than 255 bytes!')
(self.dr_len, self.xattr_len, extent_location_le, extent_location_be,
data_length_le, data_length_be_unused, dr_date, self.file_flags,
self.file_unit_size, self.interleave_gap_size, seqnum_le, seqnum_be,
self.len_fi) = struct.unpack_from(self.FMT, record[:33], 0)
# In theory we should have a check here that checks to make sure that
# the length of the record we were passed in matches the data record
# length. However, we have seen ISOs in the wild where this is
# incorrect, so we elide the check here.
if extent_location_le != utils.swab_32bit(extent_location_be):
raise pycdlibexception.PyCdlibInvalidISO(
'Little-endian (%d) and big-endian (%d) extent location disagree'
% (extent_location_le, utils.swab_32bit(extent_location_be)))
self.orig_extent_loc = extent_location_le
# Theoretically, we should check to make sure that the little endian
# data length is the same as the big endian data length. In practice,
# though, we've seen ISOs where this is wrong. Skip the check, and just
# pick the little-endian as the 'actual' size, and hope for the best.
self.data_length = data_length_le
if seqnum_le != utils.swab_16bit(seqnum_be):
raise pycdlibexception.PyCdlibInvalidISO(
'Little-endian and big-endian seqnum disagree')
self.seqnum = seqnum_le
self.date = dates.DirectoryRecordDate()
self.date.parse(dr_date)
# OK, we've unpacked what we can from the beginning of the string. Now
# we have to use the len_fi to get the rest.
self.parent = parent
self.vd = vd
if self.parent is None:
self.is_root = True
# A root directory entry should always be exactly 34 bytes.
# However, we have seen ISOs in the wild that get this wrong, so we
# elide a check for it.
self.file_ident = bytes(bytearray([record[33]]))
# A root directory entry should always have 0 as the identifier.
# However, we have seen ISOs in the wild that don't have this set
# properly to 0. In that case, we override what we parsed out from
# the original with the correct value (\x00), and hope for the best.
if self.file_ident != b'\x00':
self.file_ident = b'\x00'
self.isdir = True
else:
record_offset = 33
self.file_ident = record[record_offset:record_offset + self.len_fi]
record_offset += self.len_fi
if self.file_flags & (1 << self.FILE_FLAG_DIRECTORY_BIT):
self.isdir = True
if self.len_fi % 2 == 0:
record_offset += 1
if len(record[record_offset:]) >= XARecord.length():
xa_rec = XARecord()
try:
xa_rec.parse(record[record_offset:record_offset +
XARecord.length()])
self.xa_record = xa_rec
record_offset += XARecord.length()
except pycdlibexception.PyCdlibInvalidISO:
# We've seen some ISOs in the wild (Windows 98 SE) that
# put the XA record all the way at the back, with some
# padding. Try again from the back.
try:
xa_rec.parse(record[-XARecord.length():])
self.xa_record = xa_rec
self.xa_pad_size = len(
record) - record_offset - XARecord.length()
record_offset = len(record)
except pycdlibexception.PyCdlibInvalidISO:
pass
if len(record[record_offset:]
) >= 2 and record[record_offset:record_offset + 2] in (
b'SP', b'RR', b'CE', b'PX', b'ER', b'ES', b'PN', b'SL',
b'NM', b'CL', b'PL', b'TF', b'SF', b'RE'):
self.rock_ridge = rockridge.RockRidge()
is_first_dir_record_of_root = self.file_ident == b'\x00' and parent.parent is None
if is_first_dir_record_of_root:
bytes_to_skip = 0
elif parent.parent is None:
bytes_to_skip = parent.children[0].rock_ridge.bytes_to_skip
else:
bytes_to_skip = parent.rock_ridge.bytes_to_skip
self.rock_ridge.parse(record[record_offset:],
is_first_dir_record_of_root,
bytes_to_skip, False)
if self.xattr_len != 0:
if self.file_flags & (1 << self.FILE_FLAG_RECORD_BIT):
raise pycdlibexception.PyCdlibInvalidISO(
'Record Bit not allowed with Extended Attributes')
if self.file_flags & (1 << self.FILE_FLAG_PROTECTION_BIT):
raise pycdlibexception.PyCdlibInvalidISO(
'Protection Bit not allowed with Extended Attributes')
if self.rock_ridge is None:
ret = None
else:
ret = self.rock_ridge.rr_version
if self.is_root:
self._printable_name = b'/'
elif self.file_ident == b'\x00':
self._printable_name = b'.'
elif self.file_ident == b'\x01':
self._printable_name = b'..'
else:
self._printable_name = self.file_ident
self._initialized = True
return ret