1 # Copyright (c) 2011 The Chromium OS Authors. All rights reserved. 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 5 import logging 6 import os 7 from autotest_lib.client.common_lib import error, utils 8 from autotest_lib.client.cros import verity_utils 9 10 class platform_DMVerityCorruption(verity_utils.VerityImageTest): 11 version = 1 12 13 def mod_zerofill_block(self, run_count, backing_path, block_size, 14 block_count): 15 logging.info('mod_zerofill_block(%d, %s, %d, %d)' % ( 16 run_count, backing_path, block_size, block_count)) 17 dd_cmd = 'dd if=/dev/zero of=%s bs=%d seek=%d count=1' 18 run_count = run_count % block_count 19 verity_utils.system(dd_cmd % (backing_path, block_size, run_count)) 20 21 def mod_Afill_hash_block(self, run_count, backing_path, block_size, 22 block_count): 23 logging.info('mod_Afill_hash_block(%d, %s, %d, %d)' % ( 24 run_count, backing_path, block_size, block_count)) 25 with open(backing_path, 'wb') as dev: 26 dev.seek(block_count * block_size, os.SEEK_SET) 27 dev.seek(run_count * block_size, os.SEEK_CUR) 28 dev.write('A' * block_size) 29 30 def run_once(self): 31 # Ensure that basic verification is working. 32 # This should NOT fail. 33 self.mod_and_test(self.mod_nothing, 1, True) 34 35 # Corrupt the image once per block (on a per-block basis). 36 self.mod_and_test(self.mod_zerofill_block, self.image_blocks, False) 37 38 # Repeat except each block in the hash tree data 39 hash_blocks = (os.path.getsize(self.verity.hash_file) / 40 verity_utils.BLOCK_SIZE) 41 self.mod_and_test(self.mod_Afill_hash_block, hash_blocks, False) 42
