[CWEP002] refactor rql read security checking
Split 'check_read_perms' into 'check_relations_perms' which checks relations
'read' permissions and 'get_local_checks' which build dictionary of local
security checks (rql expression) for variables.
This allows to check relations 'read' permissions earlier in the process and so
to prepare insertion of the rql rewriter: we want to check permissions of the
computed relation, not permissions of relations introduced by the associated
rule, to conform to the CWEP.
Related to #3546717
# copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of CubicWeb.
#
# CubicWeb is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with CubicWeb. If not, see <http://www.gnu.org/licenses/>.
"""utilities for instances migration"""
__docformat__ = "restructuredtext en"
import sys
import os
import logging
import tempfile
from os.path import exists, join, basename, splitext
from itertools import chain
from logilab.common import IGNORED_EXTENSIONS
from logilab.common.decorators import cached
from logilab.common.configuration import REQUIRED, read_old_config
from logilab.common.shellutils import ASK
from logilab.common.changelog import Version
from cubicweb import ConfigurationError, ExecutionError
from cubicweb.cwconfig import CubicWebConfiguration as cwcfg
from cubicweb.toolsutils import show_diffs
def filter_scripts(config, directory, fromversion, toversion, quiet=True):
"""return a list of paths of migration files to consider to upgrade
from a version to a greater one
"""
from logilab.common.changelog import Version # doesn't work with appengine
assert fromversion
assert toversion
assert isinstance(fromversion, tuple), fromversion.__class__
assert isinstance(toversion, tuple), toversion.__class__
assert fromversion <= toversion, (fromversion, toversion)
if not exists(directory):
if not quiet:
print directory, "doesn't exists, no migration path"
return []
if fromversion == toversion:
return []
result = []
for fname in os.listdir(directory):
if fname.endswith(IGNORED_EXTENSIONS):
continue
fpath = join(directory, fname)
try:
tver, mode = fname.split('_', 1)
except ValueError:
continue
mode = mode.split('.', 1)[0]
if not config.accept_mode(mode):
continue
try:
tver = Version(tver)
except ValueError:
continue
if tver <= fromversion:
continue
if tver > toversion:
continue
result.append((tver, fpath))
# be sure scripts are executed in order
return sorted(result)
def execscript_confirm(scriptpath):
"""asks for confirmation before executing a script and provides the
ability to show the script's content
"""
while True:
answer = ASK.ask('Execute %r ?' % scriptpath,
('Y','n','show','abort'), 'Y')
if answer == 'abort':
raise SystemExit(1)
elif answer == 'n':
return False
elif answer == 'show':
stream = open(scriptpath)
scriptcontent = stream.read()
stream.close()
print
print scriptcontent
print
else:
return True
def yes(*args, **kwargs):
return True
class MigrationHelper(object):
"""class holding CubicWeb Migration Actions used by migration scripts"""
def __init__(self, config, interactive=True, verbosity=1):
self.config = config
if config:
# no config on shell to a remote instance
self.config.init_log(logthreshold=logging.ERROR)
# 0: no confirmation, 1: only main commands confirmed, 2 ask for everything
self.verbosity = verbosity
self.need_wrap = True
if not interactive or not verbosity:
self.confirm = yes
self.execscript_confirm = yes
else:
self.execscript_confirm = execscript_confirm
self._option_changes = []
self.__context = {'confirm': self.confirm,
'config': self.config,
'interactive_mode': interactive,
}
self._context_stack = []
def __getattribute__(self, name):
try:
return object.__getattribute__(self, name)
except AttributeError:
cmd = 'cmd_%s' % name
# search self.__class__ to avoid infinite recursion
if hasattr(self.__class__, cmd):
meth = getattr(self, cmd)
return lambda *args, **kwargs: self.interact(args, kwargs,
meth=meth)
raise
raise AttributeError(name)
def repo_connect(self):
return self.config.repository()
def migrate(self, vcconf, toupgrade, options):
"""upgrade the given set of cubes
`cubes` is an ordered list of 3-uple:
(cube, fromversion, toversion)
"""
if options.fs_only:
# monkey path configuration.accept_mode so database mode (e.g. Any)
# won't be accepted
orig_accept_mode = self.config.accept_mode
def accept_mode(mode):
if mode == 'Any':
return False
return orig_accept_mode(mode)
self.config.accept_mode = accept_mode
# may be an iterator
toupgrade = tuple(toupgrade)
vmap = dict( (cube, (fromver, tover)) for cube, fromver, tover in toupgrade)
ctx = self.__context
ctx['versions_map'] = vmap
if self.config.accept_mode('Any') and 'cubicweb' in vmap:
migrdir = self.config.migration_scripts_dir()
self.cmd_process_script(join(migrdir, 'bootstrapmigration_repository.py'))
for cube, fromversion, toversion in toupgrade:
if cube == 'cubicweb':
migrdir = self.config.migration_scripts_dir()
else:
migrdir = self.config.cube_migration_scripts_dir(cube)
scripts = filter_scripts(self.config, migrdir, fromversion, toversion)
if scripts:
prevversion = None
for version, script in scripts:
# take care to X.Y.Z_Any.py / X.Y.Z_common.py: we've to call
# cube_upgraded once all script of X.Y.Z have been executed
if prevversion is not None and version != prevversion:
self.cube_upgraded(cube, prevversion)
prevversion = version
self.cmd_process_script(script)
self.cube_upgraded(cube, toversion)
else:
self.cube_upgraded(cube, toversion)
def cube_upgraded(self, cube, version):
pass
def shutdown(self):
pass
def interact(self, args, kwargs, meth):
"""execute the given method according to user's confirmation"""
msg = 'Execute command: %s(%s) ?' % (
meth.__name__[4:],
', '.join([repr(arg) for arg in args] +
['%s=%r' % (n,v) for n,v in kwargs.items()]))
if 'ask_confirm' in kwargs:
ask_confirm = kwargs.pop('ask_confirm')
else:
ask_confirm = True
if not ask_confirm or self.confirm(msg):
return meth(*args, **kwargs)
def confirm(self, question, # pylint: disable=E0202
shell=True, abort=True, retry=False, pdb=False, default='y'):
"""ask for confirmation and return true on positive answer
if `retry` is true the r[etry] answer may return 2
"""
possibleanswers = ['y', 'n']
if abort:
possibleanswers.append('abort')
if pdb:
possibleanswers.append('pdb')
if shell:
possibleanswers.append('shell')
if retry:
possibleanswers.append('retry')
try:
answer = ASK.ask(question, possibleanswers, default)
except (EOFError, KeyboardInterrupt):
answer = 'abort'
if answer == 'n':
return False
if answer == 'retry':
return 2
if answer == 'abort':
raise SystemExit(1)
if answer == 'shell':
self.interactive_shell()
return self.confirm(question, shell, abort, retry, pdb, default)
if answer == 'pdb':
import pdb
pdb.set_trace()
return self.confirm(question, shell, abort, retry, pdb, default)
return True
def interactive_shell(self):
self.confirm = yes
self.need_wrap = False
# avoid '_' to be added to builtins by sys.display_hook
def do_not_add___to_builtins(obj):
if obj is not None:
print repr(obj)
sys.displayhook = do_not_add___to_builtins
local_ctx = self._create_context()
try:
import readline
from cubicweb.toolsutils import CWShellCompleter
except ImportError:
# readline not available
pass
else:
rql_completer = CWShellCompleter(local_ctx)
readline.set_completer(rql_completer.complete)
readline.parse_and_bind('tab: complete')
home_key = 'HOME'
if sys.platform == 'win32':
home_key = 'USERPROFILE'
histfile = os.path.join(os.environ[home_key], ".cwshell_history")
try:
readline.read_history_file(histfile)
except IOError:
pass
from code import interact
banner = """entering the migration python shell
just type migration commands or arbitrary python code and type ENTER to execute it
type "exit" or Ctrl-D to quit the shell and resume operation"""
# give custom readfunc to avoid http://bugs.python.org/issue1288615
def unicode_raw_input(prompt):
return unicode(raw_input(prompt), sys.stdin.encoding)
interact(banner, readfunc=unicode_raw_input, local=local_ctx)
try:
readline.write_history_file(histfile)
except IOError:
pass
# delete instance's confirm attribute to avoid questions
del self.confirm
self.need_wrap = True
@cached
def _create_context(self):
"""return a dictionary to use as migration script execution context"""
context = self.__context
for attr in dir(self):
if attr.startswith('cmd_'):
if self.need_wrap:
context[attr[4:]] = getattr(self, attr[4:])
else:
context[attr[4:]] = getattr(self, attr)
return context
def update_context(self, key, value):
for context in self._context_stack:
context[key] = value
self.__context[key] = value
def cmd_process_script(self, migrscript, funcname=None, *args, **kwargs):
"""execute a migration script in interactive mode
Display the migration script path, ask for confirmation and execute it
if confirmed
Allowed input file formats for migration scripts:
- `python` (.py)
- `sql` (.sql)
- `doctest` (.txt or .rst)
.. warning:: sql migration scripts are not available in web-only instance
You can pass script parameters with using double dash (--) in the
command line
Context environment can have these variables defined:
- __name__ : will be determine by funcname parameter
- __file__ : is the name of the script if it exists
- __args__ : script arguments coming from command-line
:param migrscript: name of the script
:param funcname: defines __name__ inside the shell (or use __main__)
:params args: optional arguments for funcname
:keyword scriptargs: optional arguments of the script
"""
ftypes = {'python': ('.py',),
'doctest': ('.txt', '.rst'),
'sql': ('.sql',)}
# sql migration scripts are not available in web-only instance
if not hasattr(self, "session"):
ftypes.pop('sql')
migrscript = os.path.normpath(migrscript)
for (script_mode, ftype) in ftypes.items():
if migrscript.endswith(ftype):
break
else:
ftypes = ', '.join(chain(*ftypes.values()))
msg = 'ignoring %s, not a valid script extension (%s)'
raise ExecutionError(msg % (migrscript, ftypes))
if not self.execscript_confirm(migrscript):
return
scriptlocals = self._create_context().copy()
scriptlocals.update({'__file__': migrscript,
'__args__': kwargs.pop("scriptargs", [])})
self._context_stack.append(scriptlocals)
if script_mode == 'python':
if funcname is None:
pyname = '__main__'
else:
pyname = splitext(basename(migrscript))[0]
scriptlocals['__name__'] = pyname
execfile(migrscript, scriptlocals)
if funcname is not None:
try:
func = scriptlocals[funcname]
self.info('found %s in locals', funcname)
assert callable(func), '%s (%s) is not callable' % (func, funcname)
except KeyError:
self.critical('no %s in script %s', funcname, migrscript)
return None
return func(*args, **kwargs)
elif script_mode == 'sql':
from cubicweb.server.sqlutils import sqlexec
sqlexec(open(migrscript).read(), self.session.system_sql)
self.commit()
else: # script_mode == 'doctest'
import doctest
return doctest.testfile(migrscript, module_relative=False,
optionflags=doctest.ELLIPSIS,
# verbose mode when user input is expected
verbose=self.verbosity==2,
report=True,
encoding='utf-8',
globs=scriptlocals)
self._context_stack.pop()
def cmd_option_renamed(self, oldname, newname):
"""a configuration option has been renamed"""
self._option_changes.append(('renamed', oldname, newname))
def cmd_option_group_changed(self, option, oldgroup, newgroup):
"""a configuration option has been moved in another group"""
self._option_changes.append(('moved', option, oldgroup, newgroup))
def cmd_option_added(self, optname):
"""a configuration option has been added"""
self._option_changes.append(('added', optname))
def cmd_option_removed(self, optname):
"""a configuration option has been removed"""
# can safely be ignored
#self._option_changes.append(('removed', optname))
def cmd_option_type_changed(self, optname, oldtype, newvalue):
"""a configuration option's type has changed"""
self._option_changes.append(('typechanged', optname, oldtype, newvalue))
def cmd_add_cubes(self, cubes):
"""modify the list of used cubes in the in-memory config
returns newly inserted cubes, including dependencies
"""
if isinstance(cubes, basestring):
cubes = (cubes,)
origcubes = self.config.cubes()
newcubes = [p for p in self.config.expand_cubes(cubes)
if not p in origcubes]
if newcubes:
self.config.add_cubes(newcubes)
return newcubes
def cmd_remove_cube(self, cube, removedeps=False):
if removedeps:
toremove = self.config.expand_cubes([cube])
else:
toremove = (cube,)
origcubes = self.config._cubes
basecubes = [c for c in origcubes if not c in toremove]
# don't fake-add any new ones, or we won't be able to really-add them later
self.config._cubes = tuple(cube for cube in self.config.expand_cubes(basecubes)
if cube in origcubes)
removed = [p for p in origcubes if not p in self.config._cubes]
if not cube in removed and cube in origcubes:
raise ConfigurationError("can't remove cube %s, "
"used as a dependency" % cube)
return removed
def rewrite_configuration(self):
configfile = self.config.main_config_file()
if self._option_changes:
read_old_config(self.config, self._option_changes, configfile)
fd, newconfig = tempfile.mkstemp()
for optdescr in self._option_changes:
if optdescr[0] == 'added':
optdict = self.config.get_option_def(optdescr[1])
if optdict.get('default') is REQUIRED:
self.config.input_option(optdescr[1], optdict)
self.config.generate_config(open(newconfig, 'w'))
show_diffs(configfile, newconfig, askconfirm=self.confirm is not yes)
os.close(fd)
if exists(newconfig):
os.unlink(newconfig)
# these are overridden by set_log_methods below
# only defining here to prevent pylint from complaining
info = warning = error = critical = exception = debug = lambda msg,*a,**kw: None
from logging import getLogger
from cubicweb import set_log_methods
set_log_methods(MigrationHelper, getLogger('cubicweb.migration'))
def version_strictly_lower(a, b):
if a:
a = Version(a)
if b:
b = Version(b)
return a < b
def max_version(a, b):
return str(max(Version(a), Version(b)))
class ConfigurationProblem(object):
"""Each cube has its own list of dependencies on other cubes/versions.
The ConfigurationProblem is used to record the loaded cubes, then to detect
inconsistencies in their dependencies.
See configuration management on wikipedia for litterature.
"""
def __init__(self, config):
self.config = config
self.cubes = {'cubicweb': cwcfg.cubicweb_version()}
def add_cube(self, name, version):
self.cubes[name] = version
def solve(self):
self.warnings = []
self.errors = []
self.dependencies = {}
self.reverse_dependencies = {}
self.constraints = {}
# read dependencies
for cube in self.cubes:
if cube == 'cubicweb': continue
self.dependencies[cube] = dict(self.config.cube_dependencies(cube))
self.dependencies[cube]['cubicweb'] = self.config.cube_depends_cubicweb_version(cube)
# compute reverse dependencies
for cube, dependencies in self.dependencies.iteritems():
for name, constraint in dependencies.iteritems():
self.reverse_dependencies.setdefault(name,set())
if constraint:
try:
oper, version = constraint.split()
self.reverse_dependencies[name].add( (oper, version, cube) )
except Exception:
self.warnings.append(
'cube %s depends on %s but constraint badly '
'formatted: %s' % (cube, name, constraint))
else:
self.reverse_dependencies[name].add( (None, None, cube) )
# check consistency
for cube, versions in sorted(self.reverse_dependencies.items()):
oper, version, source = None, None, None
# simplify constraints
if versions:
for constraint in versions:
op, ver, src = constraint
if oper is None:
oper = op
version = ver
source = src
elif op == '>=' and oper == '>=':
if version_strictly_lower(version, ver):
version = ver
source = src
elif op == None:
continue
else:
print ('unable to handle %s in %s, set to `%s %s` '
'but currently up to `%s %s`' %
(cube, source, oper, version, op, ver))
# "solve" constraint satisfaction problem
if cube not in self.cubes:
self.errors.append( ('add', cube, version, source) )
elif versions:
lower_strict = version_strictly_lower(self.cubes[cube], version)
if oper in ('>=','='):
if lower_strict:
self.errors.append( ('update', cube, version, source) )
elif oper is None:
pass # no constraint on version
else:
print 'unknown operator', oper