#
# Copyright 2017 - The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
from vts.runners.host import asserts
from vts.runners.host import const
_PERMISSION_GROUPS = 3 # 3 permission groups: owner, group, all users
_READ_PERMISSION = 4
_WRITE_PERMISSION = 2
_EXECUTE_PERMISSION = 1
def _Test(shell, *args):
"""Executes test command on device.
Args:
shell: an instance of the VTS shell.
*args: strings, the command line arguments.
Returns:
boolean, whether the condition is true.
"""
cmd = "test %s" % " ".join(args)
results = shell.Execute(cmd)
return results[const.EXIT_CODE][0] == 0
def Exists(filepath, shell):
"""Determines if a file or directory exists.
Args:
filepath: string, the path to a file or a directory.
shell: an instance of the VTS shell.
Returns:
True if exists, False otherwise.
"""
return _Test(shell, "-e", filepath)
def IsDirectory(path, shell):
"""Determines if a path is a directory.
Args:
path: string, a path on device.
shell: an instance of the VTS shell.
Returns:
True if the path is a directory, False otherwise.
"""
return _Test(shell, "-d", path)
def FindFiles(shell, path, name_pattern, options=None):
"""Searches a path for files on device.
Args:
shell: the ShellMirrorObject.
path: string, the path to search on device.
name_pattern: string, the file name pattern.
options: string, other options passed to find command.
Returns:
list of strings, the paths to the found files.
Raises:
IOError if the pattern contains quotes, or the path does not exist.
"""
if '"' in name_pattern or "'" in name_pattern:
raise IOError("File name pattern contains quotes")
cmd = "find %s -name \"%s\"" % (path, name_pattern)
if options is not None:
cmd += " " + options
results = shell.Execute(cmd)
logging.debug("%s: Shell command '%s' results: %s", path, cmd, results)
if results[const.EXIT_CODE][0] != 0:
raise IOError(results[const.STDERR][0])
stdout = str(results[const.STDOUT][0])
# Filter out empty strings before return.
return filter(None, stdout.strip().split("\n"))
def ReadFileContent(filepath, shell):
"""Read the content of a file and perform assertions.
Args:
filepath: string, path to file
shell: an instance of the VTS shell
Returns:
string, content of file
Raises:
IOError if the file does not exist.
"""
cmd = "cat %s" % filepath
results = shell.Execute(cmd)
logging.debug("%s: Shell command '%s' results: %s", filepath, cmd, results)
# checks the exit code
if results[const.EXIT_CODE][0] != 0:
raise IOError(results[const.STDERR][0])
return results[const.STDOUT][0]
def GetPermission(path, shell):
"""Read the file permission bits of a path.
Args:
filepath: string, path to a file or directory
shell: an instance of the VTS shell
Returns:
String, octal permission bits for the path
Raises:
IOError if the path does not exist or has invalid permission bits.
"""
cmd = "stat -c %%a %s" % path
results = shell.Execute(cmd)
logging.debug("%s: Shell command '%s' results: %s", path, cmd, results)
# checks the exit code
if results[const.EXIT_CODE][0] != 0:
raise IOError(results[const.STDERR][0])
accessBits = results[const.STDOUT][0].strip()
if len(accessBits) != 3:
raise IOError("%s: Wrong number of access bits (%s)" % (path,
accessBits))
return accessBits
def _HasPermission(permission_bits, groupIndex, permission):
"""Determines if the permission bits grant a permission to a group.
Args:
permission_bits: string, the octal permissions string (e.g. 741)
groupIndex: int, the index of the group into the permissions string.
(e.g. 0 is owner group). If set to -1, then all groups are
checked.
permission: the value of the permission.
Returns:
True if the group(s) has read permission.
Raises:
ValueError if the group or permission bits are invalid
"""
if groupIndex >= _PERMISSION_GROUPS:
raise ValueError("Invalid group: %s" % str(groupIndex))
if len(permission_bits) != _PERMISSION_GROUPS:
raise ValueError("Invalid permission bits: %s" % str(permission_bits))
# Define the start/end group index
start = groupIndex
end = groupIndex + 1
if groupIndex < 0:
start = 0
end = _PERMISSION_GROUPS
for i in range(start, end):
perm = int(permission_bits[i]) # throws ValueError if not an integer
if perm > 7:
raise ValueError("Invalid permission bit: %s" % str(perm))
if perm & permission == 0:
# Return false if any group lacks the permission
return False
# Return true if no group lacks the permission
return True
def IsReadable(permission_bits):
"""Determines if the permission bits grant read permission to any group.
Args:
permission_bits: string, the octal permissions string (e.g. 741)
Returns:
True if any group has read permission.
Raises:
ValueError if the group or permission bits are invalid
"""
return any([
_HasPermission(permission_bits, i, _READ_PERMISSION)
for i in range(_PERMISSION_GROUPS)
])
def IsWritable(permission_bits):
"""Determines if the permission bits grant write permission to any group.
Args:
permission_bits: string, the octal permissions string (e.g. 741)
Returns:
True if any group has write permission.
Raises:
ValueError if the group or permission bits are invalid
"""
return any([
_HasPermission(permission_bits, i, _WRITE_PERMISSION)
for i in range(_PERMISSION_GROUPS)
])
def IsExecutable(permission_bits):
"""Determines if the permission bits grant execute permission to any group.
Args:
permission_bits: string, the octal permissions string (e.g. 741)
Returns:
True if any group has execute permission.
Raises:
ValueError if the group or permission bits are invalid
"""
return any([
_HasPermission(permission_bits, i, _EXECUTE_PERMISSION)
for i in range(_PERMISSION_GROUPS)
])
def IsReadOnly(permission_bits):
"""Determines if the permission bits grant read-only permission.
Read-only permission is granted if some group has read access but no group
has write access.
Args:
permission_bits: string, the octal permissions string (e.g. 741)
Returns:
True if any group has read permission, none have write.
Raises:
ValueError if the group or permission bits are invalid
"""
return IsReadable(permission_bits) and not IsWritable(permission_bits)
def IsWriteOnly(permission_bits):
"""Determines if the permission bits grant write-only permission.
Write-only permission is granted if some group has write access but no group
has read access.
Args:
permission_bits: string, the octal permissions string (e.g. 741)
Returns:
True if any group has write permission, none have read.
Raises:
ValueError if the group or permission bits are invalid
"""
return IsWritable(permission_bits) and not IsReadable(permission_bits)
def IsReadWrite(permission_bits):
"""Determines if the permission bits grant read/write permissions.
Read-write permission is granted if some group has read access and some has
write access. The groups may be different.
Args:
permission_bits: string, the octal permissions string (e.g. 741)
Returns:
True if read and write permissions are granted to any group(s).
Raises:
ValueError if the group or permission bits are invalid
"""
return IsReadable(permission_bits) and IsWritable(permission_bits)
def assertPermissionsAndExistence(shell, path, check_permission):
"""Asserts that the specified path exists and has the correct permission.
Args:
path: string, path to validate existence and permissions
check_permission: function which takes unix permissions in octal
format and returns True if the permissions are
correct, False otherwise.
"""
asserts.assertTrue(Exists(path, shell), "%s: File does not exist." % path)
try:
permission = GetPermission(path, shell)
asserts.assertTrue(
check_permission(permission),
"%s: File has invalid permissions (%s)" % (path, permission))
except (ValueError, IOError) as e:
asserts.fail("Failed to assert permissions: %s" % str(e))