[schema migration] import refactoring to fix #1109558 and enhances things on the way
the main pb demonstrated by #1109558 was due to the fact that in-memory schema
was updated in commit_event of operations. This is undesired in most cases,
since we want the modification to be taken into account in the interval between
the modification detection and the commit_event.
I've fixed this by merging in-memory schema / database alteration operations
for most important changes, doing in-memory schema changes as they are detected
and implementing a revertcommit_event method to revert them if necessary (with
exception for removal of stuff from the schema, where this is simply done in a
postcommit_event methods).
Also, I've benefited from this to support reverting of database alteration for
some operations (more to be done there), and to move so system source alteration
code to the native source code for a nicer design.
There may be some more stuff in syncschema.py that would benefit from similar
changes, but most important things are done (at least to close #1109558, w/
unittest_syncschema and unittest_migration green).
# copyright 2003-2010 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/>.
"""Security hooks: check permissions to add/delete/update entities according to
the user connected to a session
"""
__docformat__ = "restructuredtext en"
from cubicweb import Unauthorized
from cubicweb.selectors import objectify_selector, lltrace
from cubicweb.server import BEFORE_ADD_RELATIONS, ON_COMMIT_ADD_RELATIONS, hook
def check_entity_attributes(session, entity, editedattrs=None, creation=False):
eid = entity.eid
eschema = entity.e_schema
# ._cw_skip_security_attributes is there to bypass security for attributes
# set by hooks by modifying the entity's dictionnary
dontcheck = entity._cw_skip_security_attributes
if editedattrs is None:
try:
editedattrs = entity.edited_attributes
except AttributeError:
editedattrs = entity # XXX unexpected
for attr in editedattrs:
if attr in dontcheck:
continue
rdef = eschema.rdef(attr)
if rdef.final: # non final relation are checked by other hooks
# add/delete should be equivalent (XXX: unify them into 'update' ?)
if creation and not rdef.permissions.get('update'):
continue
rdef.check_perm(session, 'update', eid=eid)
# don't update dontcheck until everything went fine: see usage in
# after_update_entity, where if we got an Unauthorized at hook time, we will
# retry and commit time
dontcheck |= frozenset(editedattrs)
class _CheckEntityPermissionOp(hook.LateOperation):
def precommit_event(self):
#print 'CheckEntityPermissionOp', self.session.user, self.entity, self.action
session = self.session
for values in session.transaction_data.pop('check_entity_perm_op'):
entity = session.entity_from_eid(values[0])
action = values[1]
entity.cw_check_perm(action)
check_entity_attributes(session, entity, values[2:],
creation=self.creation)
def commit_event(self):
pass
class _CheckRelationPermissionOp(hook.LateOperation):
def precommit_event(self):
session = self.session
for args in session.transaction_data.pop('check_relation_perm_op'):
action, rschema, eidfrom, eidto = args
rdef = rschema.rdef(session.describe(eidfrom)[0],
session.describe(eidto)[0])
rdef.check_perm(session, action, fromeid=eidfrom, toeid=eidto)
def commit_event(self):
pass
@objectify_selector
@lltrace
def write_security_enabled(cls, req, **kwargs):
if req is None or not req.write_security:
return 0
return 1
class SecurityHook(hook.Hook):
__abstract__ = True
category = 'security'
__select__ = hook.Hook.__select__ & write_security_enabled()
class AfterAddEntitySecurityHook(SecurityHook):
__regid__ = 'securityafteraddentity'
events = ('after_add_entity',)
def __call__(self):
hook.set_operation(self._cw, 'check_entity_perm_op',
(self.entity.eid, 'add') + tuple(self.entity.edited_attributes),
_CheckEntityPermissionOp, creation=True)
class AfterUpdateEntitySecurityHook(SecurityHook):
__regid__ = 'securityafterupdateentity'
events = ('after_update_entity',)
def __call__(self):
try:
# check user has permission right now, if not retry at commit time
self.entity.cw_check_perm('update')
check_entity_attributes(self._cw, self.entity)
except Unauthorized:
self.entity._cw_clear_local_perm_cache('update')
# save back editedattrs in case the entity is reedited later in the
# same transaction, which will lead to edited_attributes being
# overwritten
hook.set_operation(self._cw, 'check_entity_perm_op',
(self.entity.eid, 'update') + tuple(self.entity.edited_attributes),
_CheckEntityPermissionOp, creation=False)
class BeforeDelEntitySecurityHook(SecurityHook):
__regid__ = 'securitybeforedelentity'
events = ('before_delete_entity',)
def __call__(self):
self.entity.cw_check_perm('delete')
class BeforeAddRelationSecurityHook(SecurityHook):
__regid__ = 'securitybeforeaddrelation'
events = ('before_add_relation',)
def __call__(self):
if self.rtype in BEFORE_ADD_RELATIONS:
nocheck = self._cw.transaction_data.get('skip-security', ())
if (self.eidfrom, self.rtype, self.eidto) in nocheck:
return
rschema = self._cw.repo.schema[self.rtype]
rdef = rschema.rdef(self._cw.describe(self.eidfrom)[0],
self._cw.describe(self.eidto)[0])
rdef.check_perm(self._cw, 'add', fromeid=self.eidfrom, toeid=self.eidto)
class AfterAddRelationSecurityHook(SecurityHook):
__regid__ = 'securityafteraddrelation'
events = ('after_add_relation',)
def __call__(self):
if not self.rtype in BEFORE_ADD_RELATIONS:
nocheck = self._cw.transaction_data.get('skip-security', ())
if (self.eidfrom, self.rtype, self.eidto) in nocheck:
return
rschema = self._cw.repo.schema[self.rtype]
if self.rtype in ON_COMMIT_ADD_RELATIONS:
hook.set_operation(self._cw, 'check_relation_perm_op',
('add', rschema, self.eidfrom, self.eidto),
_CheckRelationPermissionOp)
else:
rdef = rschema.rdef(self._cw.describe(self.eidfrom)[0],
self._cw.describe(self.eidto)[0])
rdef.check_perm(self._cw, 'add', fromeid=self.eidfrom, toeid=self.eidto)
class BeforeDeleteRelationSecurityHook(SecurityHook):
__regid__ = 'securitybeforedelrelation'
events = ('before_delete_relation',)
def __call__(self):
nocheck = self._cw.transaction_data.get('skip-security', ())
if (self.eidfrom, self.rtype, self.eidto) in nocheck:
return
rschema = self._cw.repo.schema[self.rtype]
rdef = rschema.rdef(self._cw.describe(self.eidfrom)[0],
self._cw.describe(self.eidto)[0])
rdef.check_perm(self._cw, 'delete', fromeid=self.eidfrom, toeid=self.eidto)