tools/checkperms/checkperms.py

   1 #!/usr/bin/env python
   2 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   3 # Use of this source code is governed by a BSD-style license that can be
   4 # found in the LICENSE file.
   5
   6 """Makes sure files have the right permissions.
   7
   8 Some developers have broken SCM configurations that flip the executable
   9 permission on for no good reason. Unix developers who run ls --color will then
  10 see .cc files in green and get confused.
  11
  12 - For file extensions that must be executable, add it to EXECUTABLE_EXTENSIONS.
  13 - For file extensions that must not be executable, add it to
  14   NOT_EXECUTABLE_EXTENSIONS.
  15 - To ignore all the files inside a directory, add it to IGNORED_PATHS.
  16 - For file base name with ambiguous state and that should not be checked for
  17   shebang, add it to IGNORED_FILENAMES.
  18
  19 Any file not matching the above will be opened and looked if it has a shebang
  20 or an ELF header. If this does not match the executable bit on the file, the
  21 file will be flagged.
  22
  23 Note that all directory separators must be slashes (Unix-style) and not
  24 backslashes. All directories should be relative to the source root and all
  25 file paths should be only lowercase.
  26 """
  27
  28 import json
  29 import logging
  30 import optparse
  31 import os
  32 import stat
  33 import string
  34 import subprocess
  35 import sys
  36
  37 #### USER EDITABLE SECTION STARTS HERE ####
  38
  39 # Files with these extensions must have executable bit set.
  40 #
  41 # Case-sensitive.
  42 EXECUTABLE_EXTENSIONS = (
  43   'bat',
  44   'dll',
  45   'dylib',
  46   'exe',
  47 )
  48
  49 # These files must have executable bit set.
  50 #
  51 # Case-insensitive, lower-case only.
  52 EXECUTABLE_PATHS = (
  53   'chrome/test/data/app_shim/app_shim_32_bit.app/contents/'
  54       'macos/app_mode_loader',
  55   'chrome/test/data/extensions/uitest/plugins/plugin.plugin/contents/'
  56       'macos/testnetscapeplugin',
  57   'chrome/test/data/extensions/uitest/plugins_private/plugin.plugin/contents/'
  58       'macos/testnetscapeplugin',
  59 )
  60
  61 # These files must not have the executable bit set. This is mainly a performance
  62 # optimization as these files are not checked for shebang. The list was
  63 # partially generated from:
  64 # git ls-files | grep "\\." | sed 's/.*\.//' | sort | uniq -c | sort -b -g
  65 #
  66 # Case-sensitive.
  67 NON_EXECUTABLE_EXTENSIONS = (
  68   '1',
  69   '3ds',
  70   'S',
  71   'am',
  72   'applescript',
  73   'asm',
  74   'c',
  75   'cc',
  76   'cfg',
  77   'chromium',
  78   'cpp',
  79   'crx',
  80   'cs',
  81   'css',
  82   'cur',
  83   'def',
  84   'der',
  85   'expected',
  86   'gif',
  87   'grd',
  88   'gyp',
  89   'gypi',
  90   'h',
  91   'hh',
  92   'htm',
  93   'html',
  94   'hyph',
  95   'ico',
  96   'idl',
  97   'java',
  98   'jpg',
  99   'js',
 100   'json',
 101   'm',
 102   'm4',
 103   'mm',
 104   'mms',
 105   'mock-http-headers',
 106   'nexe',
 107   'nmf',
 108   'onc',
 109   'pat',
 110   'patch',
 111   'pdf',
 112   'pem',
 113   'plist',
 114   'png',
 115   'proto',
 116   'rc',
 117   'rfx',
 118   'rgs',
 119   'rules',
 120   'spec',
 121   'sql',
 122   'srpc',
 123   'svg',
 124   'tcl',
 125   'test',
 126   'tga',
 127   'txt',
 128   'vcproj',
 129   'vsprops',
 130   'webm',
 131   'word',
 132   'xib',
 133   'xml',
 134   'xtb',
 135   'zip',
 136 )
 137
 138 # These files must not have executable bit set.
 139 #
 140 # Case-insensitive, lower-case only.
 141 NON_EXECUTABLE_PATHS = (
 142   'build/android/tests/symbolize/liba.so',
 143   'build/android/tests/symbolize/libb.so',
 144   'chrome/installer/mac/sign_app.sh.in',
 145   'chrome/installer/mac/sign_versioned_dir.sh.in',
 146   'chrome/test/data/extensions/uitest/plugins/plugin32.so',
 147   'chrome/test/data/extensions/uitest/plugins/plugin64.so',
 148   'chrome/test/data/extensions/uitest/plugins_private/plugin32.so',
 149   'chrome/test/data/extensions/uitest/plugins_private/plugin64.so',
 150   'components/test/data/component_updater/ihfokbkgjpifnbbojhneepfflplebdkc/'
 151       'ihfokbkgjpifnbbojhneepfflplebdkc_1/a_changing_binary_file',
 152   'components/test/data/component_updater/ihfokbkgjpifnbbojhneepfflplebdkc/'
 153       'ihfokbkgjpifnbbojhneepfflplebdkc_2/a_changing_binary_file',
 154   'courgette/testdata/elf-32-1',
 155   'courgette/testdata/elf-32-2',
 156   'courgette/testdata/elf-64',
 157 )
 158
 159 # File names that are always whitelisted.  (These are mostly autoconf spew.)
 160 #
 161 # Case-sensitive.
 162 IGNORED_FILENAMES = (
 163   'config.guess',
 164   'config.sub',
 165   'configure',
 166   'depcomp',
 167   'install-sh',
 168   'missing',
 169   'mkinstalldirs',
 170   'naclsdk',
 171   'scons',
 172 )
 173
 174 # File paths starting with one of these will be ignored as well.
 175 # Please consider fixing your file permissions, rather than adding to this list.
 176 #
 177 # Case-insensitive, lower-case only.
 178 IGNORED_PATHS = (
 179   'native_client_sdk/src/build_tools/sdk_tools/third_party/fancy_urllib/'
 180       '__init__.py',
 181   'out/',
 182   # TODO(maruel): Fix these.
 183   'third_party/android_testrunner/',
 184   'third_party/bintrees/',
 185   'third_party/closure_linter/',
 186   'third_party/devscripts/licensecheck.pl.vanilla',
 187   'third_party/hyphen/',
 188   'third_party/jemalloc/',
 189   'third_party/lcov-1.9/contrib/galaxy/conglomerate_functions.pl',
 190   'third_party/lcov-1.9/contrib/galaxy/gen_makefile.sh',
 191   'third_party/lcov/contrib/galaxy/conglomerate_functions.pl',
 192   'third_party/lcov/contrib/galaxy/gen_makefile.sh',
 193   'third_party/libevent/autogen.sh',
 194   'third_party/libevent/test/test.sh',
 195   'third_party/libxml/linux/xml2-config',
 196   'third_party/libxml/src/ltmain.sh',
 197   'third_party/mesa/',
 198   'third_party/protobuf/',
 199   'third_party/python_gflags/gflags.py',
 200   'third_party/sqlite/',
 201   'third_party/talloc/script/mksyms.sh',
 202   'third_party/tcmalloc/',
 203   'third_party/tlslite/setup.py',
 204 )
 205
 206 #### USER EDITABLE SECTION ENDS HERE ####
 207
 208 assert set(EXECUTABLE_EXTENSIONS) & set(NON_EXECUTABLE_EXTENSIONS) == set()
 209 assert set(EXECUTABLE_PATHS) & set(NON_EXECUTABLE_PATHS) == set()
 210
 211 VALID_CHARS = set(string.ascii_lowercase + string.digits + '/-_.')
 212 for paths in (EXECUTABLE_PATHS, NON_EXECUTABLE_PATHS, IGNORED_PATHS):
 213   assert all([set(path).issubset(VALID_CHARS) for path in paths])
 214
 215
 216 def capture(cmd, cwd):
 217   """Returns the output of a command.
 218
 219   Ignores the error code or stderr.
 220   """
 221   logging.debug('%s; cwd=%s' % (' '.join(cmd), cwd))
 222   env = os.environ.copy()
 223   env['LANGUAGE'] = 'en_US.UTF-8'
 224   p = subprocess.Popen(
 225       cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=cwd, env=env)
 226   return p.communicate()[0]
 227
 228
 229 def get_git_root(dir_path):
 230   """Returns the git checkout root or None."""
 231   root = capture(['git', 'rev-parse', '--show-toplevel'], dir_path).strip()
 232   if root:
 233     return root
 234
 235
 236 def is_ignored(rel_path):
 237   """Returns True if rel_path is in our whitelist of files to ignore."""
 238   rel_path = rel_path.lower()
 239   return (
 240       os.path.basename(rel_path) in IGNORED_FILENAMES or
 241       rel_path.lower().startswith(IGNORED_PATHS))
 242
 243
 244 def must_be_executable(rel_path):
 245   """The file name represents a file type that must have the executable bit
 246   set.
 247   """
 248   return (os.path.splitext(rel_path)[1][1:] in EXECUTABLE_EXTENSIONS or
 249           rel_path.lower() in EXECUTABLE_PATHS)
 250
 251
 252 def must_not_be_executable(rel_path):
 253   """The file name represents a file type that must not have the executable
 254   bit set.
 255   """
 256   return (os.path.splitext(rel_path)[1][1:] in NON_EXECUTABLE_EXTENSIONS or
 257           rel_path.lower() in NON_EXECUTABLE_PATHS)
 258
 259
 260 def has_executable_bit(full_path):
 261   """Returns if any executable bit is set."""
 262   permission = stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH
 263   return bool(permission & os.stat(full_path).st_mode)
 264
 265
 266 def has_shebang_or_is_elf(full_path):
 267   """Returns if the file starts with #!/ or is an ELF binary.
 268
 269   full_path is the absolute path to the file.
 270   """
 271   with open(full_path, 'rb') as f:
 272     data = f.read(4)
 273     return (data[:3] == '#!/', data == '\x7fELF')
 274
 275
 276 def check_file(root_path, rel_path):
 277   """Checks the permissions of the file whose path is root_path + rel_path and
 278   returns an error if it is inconsistent. Returns None on success.
 279
 280   It is assumed that the file is not ignored by is_ignored().
 281
 282   If the file name is matched with must_be_executable() or
 283   must_not_be_executable(), only its executable bit is checked.
 284   Otherwise, the first few bytes of the file are read to verify if it has a
 285   shebang or ELF header and compares this with the executable bit on the file.
 286   """
 287   full_path = os.path.join(root_path, rel_path)
 288   def result_dict(error):
 289     return {
 290       'error': error,
 291       'full_path': full_path,
 292       'rel_path': rel_path,
 293     }
 294   try:
 295     bit = has_executable_bit(full_path)
 296   except OSError:
 297     # It's faster to catch exception than call os.path.islink(). Chromium
 298     # tree happens to have invalid symlinks under
 299     # third_party/openssl/openssl/test/.
 300     return None
 301
 302   if must_be_executable(rel_path):
 303     if not bit:
 304       return result_dict('Must have executable bit set')
 305     return
 306   if must_not_be_executable(rel_path):
 307     if bit:
 308       return result_dict('Must not have executable bit set')
 309     return
 310
 311   # For the others, it depends on the file header.
 312   (shebang, elf) = has_shebang_or_is_elf(full_path)
 313   if bit != (shebang or elf):
 314     if bit:
 315       return result_dict('Has executable bit but not shebang or ELF header')
 316     if shebang:
 317       return result_dict('Has shebang but not executable bit')
 318     return result_dict('Has ELF header but not executable bit')
 319
 320
 321 def check_files(root, files):
 322   gen = (check_file(root, f) for f in files if not is_ignored(f))
 323   return filter(None, gen)
 324
 325
 326 class ApiBase(object):
 327   def __init__(self, root_dir, bare_output):
 328     self.root_dir = root_dir
 329     self.bare_output = bare_output
 330     self.count = 0
 331     self.count_read_header = 0
 332
 333   def check_file(self, rel_path):
 334     logging.debug('check_file(%s)' % rel_path)
 335     self.count += 1
 336
 337     if (not must_be_executable(rel_path) and
 338         not must_not_be_executable(rel_path)):
 339       self.count_read_header += 1
 340
 341     return check_file(self.root_dir, rel_path)
 342
 343   def check_dir(self, rel_path):
 344     return self.check(rel_path)
 345
 346   def check(self, start_dir):
 347     """Check the files in start_dir, recursively check its subdirectories."""
 348     errors = []
 349     items = self.list_dir(start_dir)
 350     logging.info('check(%s) -> %d' % (start_dir, len(items)))
 351     for item in items:
 352       full_path = os.path.join(self.root_dir, start_dir, item)
 353       rel_path = full_path[len(self.root_dir) + 1:]
 354       if is_ignored(rel_path):
 355         continue
 356       if os.path.isdir(full_path):
 357         # Depth first.
 358         errors.extend(self.check_dir(rel_path))
 359       else:
 360         error = self.check_file(rel_path)
 361         if error:
 362           errors.append(error)
 363     return errors
 364
 365   def list_dir(self, start_dir):
 366     """Lists all the files and directory inside start_dir."""
 367     return sorted(
 368       x for x in os.listdir(os.path.join(self.root_dir, start_dir))
 369       if not x.startswith('.')
 370     )
 371
 372
 373 class ApiAllFilesAtOnceBase(ApiBase):
 374   _files = None
 375
 376   def list_dir(self, start_dir):
 377     """Lists all the files and directory inside start_dir."""
 378     if self._files is None:
 379       self._files = sorted(self._get_all_files())
 380       if not self.bare_output:
 381         print 'Found %s files' % len(self._files)
 382     start_dir = start_dir[len(self.root_dir) + 1:]
 383     return [
 384       x[len(start_dir):] for x in self._files if x.startswith(start_dir)
 385     ]
 386
 387   def _get_all_files(self):
 388     """Lists all the files and directory inside self._root_dir."""
 389     raise NotImplementedError()
 390
 391
 392 class ApiGit(ApiAllFilesAtOnceBase):
 393   def _get_all_files(self):
 394     return capture(['git', 'ls-files'], cwd=self.root_dir).splitlines()
 395
 396
 397 def get_scm(dir_path, bare):
 398   """Returns a properly configured ApiBase instance."""
 399   cwd = os.getcwd()
 400   root = get_git_root(dir_path or cwd)
 401   if root:
 402     if not bare:
 403       print('Found git repository at %s' % root)
 404     return ApiGit(dir_path or root, bare)
 405
 406   # Returns a non-scm aware checker.
 407   if not bare:
 408     print('Failed to determine the SCM for %s' % dir_path)
 409   return ApiBase(dir_path or cwd, bare)
 410
 411
 412 def main():
 413   usage = """Usage: python %prog [--root <root>] [tocheck]
 414   tocheck  Specifies the directory, relative to root, to check. This defaults
 415            to "." so it checks everything.
 416
 417 Examples:
 418   python %prog
 419   python %prog --root /path/to/source chrome"""
 420
 421   parser = optparse.OptionParser(usage=usage)
 422   parser.add_option(
 423       '--root',
 424       help='Specifies the repository root. This defaults '
 425            'to the checkout repository root')
 426   parser.add_option(
 427       '-v', '--verbose', action='count', default=0, help='Print debug logging')
 428   parser.add_option(
 429       '--bare',
 430       action='store_true',
 431       default=False,
 432       help='Prints the bare filename triggering the checks')
 433   parser.add_option(
 434       '--file', action='append', dest='files',
 435       help='Specifics a list of files to check the permissions of. Only these '
 436       'files will be checked')
 437   parser.add_option('--json', help='Path to JSON output file')
 438   options, args = parser.parse_args()
 439
 440   levels = [logging.ERROR, logging.INFO, logging.DEBUG]
 441   logging.basicConfig(level=levels[min(len(levels) - 1, options.verbose)])
 442
 443   if len(args) > 1:
 444     parser.error('Too many arguments used')
 445
 446   if options.root:
 447     options.root = os.path.abspath(options.root)
 448
 449   if options.files:
 450     # --file implies --bare (for PRESUBMIT.py).
 451     options.bare = True
 452
 453     errors = check_files(options.root, options.files)
 454   else:
 455     api = get_scm(options.root, options.bare)
 456     start_dir = args[0] if args else api.root_dir
 457     errors = api.check(start_dir)
 458
 459     if not options.bare:
 460       print('Processed %s files, %d files where tested for shebang/ELF '
 461             'header' % (api.count, api.count_read_header))
 462
 463   if options.json:
 464     with open(options.json, 'w') as f:
 465       json.dump(errors, f)
 466
 467   if errors:
 468     if options.bare:
 469       print '\n'.join(e['full_path'] for e in errors)
 470     else:
 471       print '\nFAILED\n'
 472       print '\n'.join('%s: %s' % (e['full_path'], e['error']) for e in errors)
 473     return 1
 474   if not options.bare:
 475     print '\nSUCCESS\n'
 476   return 0
 477
 478
 479 if '__main__' == __name__:
 480   sys.exit(main())