def test_cbfs_invalid_file_type_on_read(self):
"""Check handling of an invalid file type when reading the CBFS"""
size = 0xb0
cbw = CbfsWriter(size)
cbw.add_file_raw('u-boot', U_BOOT_DATA)
data = cbw.get_data()
# Read in the first file header
cbr = cbfs_util.CbfsReader(data, read=False)
with io.BytesIO(data) as fd:
self.assertTrue(cbr._find_and_read_header(fd, len(data)))
pos = fd.tell()
hdr_data = fd.read(cbfs_util.FILE_HEADER_LEN)
magic, size, ftype, attr, offset = struct.unpack(
cbfs_util.FILE_HEADER_FORMAT, hdr_data)
# Create a new CBFS with a change to the file type
ftype = 0xff
newdata = data[:pos]
newdata += struct.pack(cbfs_util.FILE_HEADER_FORMAT, magic, size,
ftype, attr, offset)
newdata += data[pos + cbfs_util.FILE_HEADER_LEN:]
# Read in this CBFS and make sure that the reader complains
with self.assertRaises(ValueError) as e:
cbfs_util.CbfsReader(newdata)
self.assertIn('Unknown type 0xff when reading', str(e.exception))
def _check_hdr(self,
data,
size,
offset=0,
arch=cbfs_util.ARCHITECTURE_X86):
"""Check that the CBFS has the expected header
Args:
data: Data to check
size: Expected ROM size
offset: Expected offset to first CBFS file
arch: Expected architecture
Returns:
CbfsReader object containing the CBFS
"""
cbfs = cbfs_util.CbfsReader(data)
self.assertEqual(cbfs_util.HEADER_MAGIC, cbfs.magic)
self.assertEqual(cbfs_util.HEADER_VERSION2, cbfs.version)
self.assertEqual(size, cbfs.rom_size)
self.assertEqual(0, cbfs.boot_block_size)
self.assertEqual(cbfs_util.ENTRY_ALIGN, cbfs.align)
self.assertEqual(offset, cbfs.cbfs_offset)
self.assertEqual(arch, cbfs.arch)
return cbfs
def test_cbfs_missing_attribute(self):
"""Check handling of an incomplete attribute tag"""
if not self.have_lz4:
self.skipTest('lz4 --no-frame-crc not available')
size = 0x140
cbw = CbfsWriter(size)
cbw.add_file_raw('u-boot',
COMPRESS_DATA,
None,
compress=cbfs_util.COMPRESS_LZ4)
data = cbw.get_data()
# Read in the CBFS master header (only), then stop
cbr = cbfs_util.CbfsReader(data, read=False)
with io.BytesIO(data) as fd:
self.assertTrue(cbr._find_and_read_header(fd, len(data)))
pos = fd.tell()
# Create a new CBFS with only the first 4 bytes of the compression tag,
# then try to read the file
tag_pos = pos + cbfs_util.FILE_HEADER_LEN + cbfs_util.FILENAME_ALIGN
newdata = data[:tag_pos + 4]
with test_util.capture_sys_output() as (stdout, _stderr):
with io.BytesIO(newdata) as fd:
fd.seek(pos)
self.assertEqual(False, cbr._read_next_file(fd))
self.assertIn('Attribute tag at %x ran out of data' % tag_pos,
stdout.getvalue())
def test_cbfs_bad_attribute(self):
"""Check handling of bad attribute tag"""
if not self.have_lz4:
self.skipTest('lz4 --no-frame-crc not available')
size = 0x140
cbw = CbfsWriter(size)
cbw.add_file_raw('u-boot',
COMPRESS_DATA,
None,
compress=cbfs_util.COMPRESS_LZ4)
data = cbw.get_data()
# Search the CBFS for the expected compression tag
with io.BytesIO(data) as fd:
while True:
pos = fd.tell()
tag, = struct.unpack('>I', fd.read(4))
if tag == cbfs_util.FILE_ATTR_TAG_COMPRESSION:
break
# Create a new CBFS with the tag changed to something invalid
newdata = data[:pos] + struct.pack('>I', 0x123) + data[pos + 4:]
with test_util.capture_sys_output() as (stdout, _stderr):
cbfs_util.CbfsReader(newdata)
self.assertEqual('Unknown attribute tag 123\n', stdout.getvalue())
def ReadChildData(self, child, decomp=True):
if not self.reader:
data = super().ReadData(True)
self.reader = cbfs_util.CbfsReader(data)
reader = self.reader
cfile = reader.files.get(child.name)
return cfile.data if decomp else cfile.orig_data
def test_cbfs_check_offset(self):
"""Test that we can discover the offset of a file after writing it"""
size = 0xb0
cbw = CbfsWriter(size)
cbw.add_file_raw('u-boot', U_BOOT_DATA)
cbw.add_file_raw('u-boot-dtb', U_BOOT_DTB_DATA)
data = cbw.get_data()
cbfs = cbfs_util.CbfsReader(data)
self.assertEqual(0x38, cbfs.files['u-boot'].cbfs_offset)
self.assertEqual(0x78, cbfs.files['u-boot-dtb'].cbfs_offset)
def test_cbfs_file_master_header(self):
"""Check handling of a file containing a master header"""
size = 0x100
cbw = CbfsWriter(size)
cbw._add_fileheader = True
cbw.add_file_raw('u-boot', U_BOOT_DATA)
data = cbw.get_data()
cbr = cbfs_util.CbfsReader(data)
self.assertIn('u-boot', cbr.files)
self.assertEqual(size, cbr.rom_size)
def test_cbfs_debug(self):
"""Check debug output"""
size = 0x70
cbw = CbfsWriter(size)
cbw.add_file_raw('u-boot', U_BOOT_DATA)
data = cbw.get_data()
try:
cbfs_util.DEBUG = True
with test_util.capture_sys_output() as (stdout, _stderr):
cbfs_util.CbfsReader(data)
self.assertEqual('name u-boot\ndata %s\n' % U_BOOT_DATA,
stdout.getvalue())
finally:
cbfs_util.DEBUG = False
def test_cbfs_bad_header(self):
"""Check handling of a bad master header"""
size = 0x70
cbw = CbfsWriter(size)
cbw.add_file_raw('u-boot', U_BOOT_DATA)
data = cbw.get_data()
# Drop most of the header and try reading the modified CBFS
newdata = data[:cbw._header_offset + 4]
with test_util.capture_sys_output() as (stdout, _stderr):
with self.assertRaises(ValueError) as e:
cbfs_util.CbfsReader(newdata)
self.assertIn('Relative offset seems wrong', stdout.getvalue())
self.assertIn('Cannot find master header', str(e.exception))
def test_cbfs_bad_header_ptr(self):
"""Check handling of a bad master-header pointer"""
size = 0x70
cbw = CbfsWriter(size)
cbw.add_file_raw('u-boot', U_BOOT_DATA)
data = cbw.get_data()
# Add one to the pointer to make it invalid
newdata = data[:-4] + struct.pack('<I', cbw._header_offset + 1)
# We should still be able to find the master header by searching
with test_util.capture_sys_output() as (stdout, _stderr):
cbfs = cbfs_util.CbfsReader(newdata)
self.assertIn('Relative offset seems wrong', stdout.getvalue())
self.assertIn('u-boot', cbfs.files)
self.assertEqual(size, cbfs.rom_size)
def test_cbfs_bad_file_header(self):
"""Check handling of a bad file header"""
size = 0x70
cbw = CbfsWriter(size)
cbw.add_file_raw('u-boot', U_BOOT_DATA)
data = cbw.get_data()
# Read in the CBFS master header (only), then stop
cbr = cbfs_util.CbfsReader(data, read=False)
with io.BytesIO(data) as fd:
self.assertTrue(cbr._find_and_read_header(fd, len(data)))
pos = fd.tell()
# Remove all but 4 bytes of the file headerm and try to read the file
newdata = data[:pos + 4]
with test_util.capture_sys_output() as (stdout, _stderr):
with io.BytesIO(newdata) as fd:
fd.seek(pos)
self.assertEqual(False, cbr._read_next_file(fd))
self.assertIn('File header at 0x0 ran out of data', stdout.getvalue())
def test_cbfs_bad_file_string(self):
"""Check handling of an incomplete filename string"""
size = 0x70
cbw = CbfsWriter(size)
cbw.add_file_raw('16-characters xx', U_BOOT_DATA)
data = cbw.get_data()
# Read in the CBFS master header (only), then stop
cbr = cbfs_util.CbfsReader(data, read=False)
with io.BytesIO(data) as fd:
self.assertTrue(cbr._find_and_read_header(fd, len(data)))
pos = fd.tell()
# Create a new CBFS with only the first 16 bytes of the file name, then
# try to read the file
newdata = data[:pos + cbfs_util.FILE_HEADER_LEN + 16]
with test_util.capture_sys_output() as (stdout, _stderr):
with io.BytesIO(newdata) as fd:
fd.seek(pos)
self.assertEqual(False, cbr._read_next_file(fd))
self.assertIn(
'String at %#x ran out of data' % cbfs_util.FILE_HEADER_LEN,
stdout.getvalue())
