Files
mayan-edms/mayan/apps/acls/managers.py
2017-09-06 23:09:54 -04:00

222 lines
8.3 KiB
Python

from __future__ import absolute_import, unicode_literals
import logging
from django.contrib.contenttypes.models import ContentType
from django.core.exceptions import PermissionDenied
from django.db import models
from django.db.models import Q
from django.utils.translation import ugettext, ugettext_lazy as _
from common.utils import return_attrib
from permissions import Permission
from permissions.models import StoredPermission
from .exceptions import PermissionNotValidForClass
from .classes import ModelPermission
logger = logging.getLogger(__name__)
class AccessControlListManager(models.Manager):
"""
Implement a 3 tier permission system, involving a permissions, an actor
and an object
"""
def check_access(self, permissions, user, obj, related=None):
if user.is_superuser or user.is_staff:
logger.debug(
'Permissions "%s" on "%s" granted to user "%s" as superuser '
'or staff', permissions, obj, user
)
return True
try:
return Permission.check_permissions(
requester=user, permissions=permissions
)
except PermissionDenied:
try:
stored_permissions = [
permission.stored_permission for permission in permissions
]
except TypeError:
# Not a list of permissions, just one
stored_permissions = (permissions.stored_permission,)
if related:
obj = return_attrib(obj, related)
try:
parent_accessor = ModelPermission.get_inheritance(
model=obj._meta.model
)
except AttributeError:
# AttributeError means non model objects: ie Statistics
# These can't have ACLs so we raise PermissionDenied
raise PermissionDenied(_('Insufficient access for: %s') % obj)
except KeyError:
pass
else:
try:
return self.check_access(
obj=getattr(obj, parent_accessor),
permissions=permissions, user=user
)
except PermissionDenied:
pass
user_roles = []
for group in user.groups.all():
for role in group.roles.all():
if set(stored_permissions).intersection(set(self.get_inherited_permissions(role=role, obj=obj))):
logger.debug(
'Permissions "%s" on "%s" granted to user "%s" through role "%s" via inherited ACL',
permissions, obj, user, role
)
return True
user_roles.append(role)
if not self.filter(content_type=ContentType.objects.get_for_model(obj), object_id=obj.pk, permissions__in=stored_permissions, role__in=user_roles).exists():
logger.debug(
'Permissions "%s" on "%s" denied for user "%s"',
permissions, obj, user
)
raise PermissionDenied(ugettext('Insufficient access for: %s') % obj)
logger.debug(
'Permissions "%s" on "%s" granted to user "%s" through roles "%s" by direct ACL',
permissions, obj, user, user_roles
)
def filter_by_access(self, permission, user, queryset):
if user.is_superuser or user.is_staff:
logger.debug(
'Unfiltered queryset returned to user "%s" as superuser '
'or staff', user
)
return queryset
try:
Permission.check_permissions(
requester=user, permissions=(permission,)
)
except PermissionDenied:
user_roles = []
for group in user.groups.all():
for role in group.roles.all():
user_roles.append(role)
try:
parent_accessor = ModelPermission.get_inheritance(
model=queryset.model
)
except KeyError:
parent_acl_query = Q()
else:
instance = queryset.first()
if instance:
parent_object = getattr(instance, parent_accessor)
try:
# Try to see if parent_object is a function
parent_object()
except TypeError:
# Is not a function, try it as a field
parent_content_type = ContentType.objects.get_for_model(
parent_object
)
parent_queryset = self.filter(
content_type=parent_content_type, role__in=user_roles,
permissions=permission.stored_permission
)
parent_acl_query = Q(
**{
'{}__pk__in'.format(
parent_accessor
): parent_queryset.values_list(
'object_id', flat=True
)
}
)
else:
# Is a function. Can't perform Q object filtering.
# Perform iterative filtering.
result = []
for entry in queryset:
try:
self.check_access(permissions=permission, user=user, obj=entry)
except PermissionDenied:
pass
else:
result.append(entry.pk)
return queryset.filter(pk__in=result)
else:
parent_acl_query = Q()
# Directly granted access
content_type = ContentType.objects.get_for_model(queryset.model)
acl_query = Q(pk__in=self.filter(
content_type=content_type, role__in=user_roles,
permissions=permission.stored_permission
).values_list('object_id', flat=True))
logger.debug(
'Filtered queryset returned to user "%s" based on roles "%s"',
user, user_roles
)
return queryset.filter(parent_acl_query | acl_query)
else:
return queryset
def get_inherited_permissions(self, role, obj):
try:
instance = obj.first()
except AttributeError:
instance = obj
else:
if not instance:
return StoredPermission.objects.none()
try:
parent_accessor = ModelPermission.get_inheritance(type(instance))
except KeyError:
return StoredPermission.objects.none()
else:
parent_object = return_attrib(instance, parent_accessor)
content_type = ContentType.objects.get_for_model(parent_object)
try:
return self.get(
role=role, content_type=content_type,
object_id=parent_object.pk
).permissions.all()
except self.model.DoesNotExist:
return StoredPermission.objects.none()
def grant(self, permission, role, obj):
class_permissions = ModelPermission.get_for_class(klass=obj.__class__)
if permission not in class_permissions:
raise PermissionNotValidForClass
content_type = ContentType.objects.get_for_model(model=obj)
acl, created = self.get_or_create(
content_type=content_type, object_id=obj.pk,
role=role
)
acl.permissions.add(permission.stored_permission)
def revoke(self, permission, role, obj):
content_type = ContentType.objects.get_for_model(model=obj)
acl, created = self.get_or_create(
content_type=content_type, object_id=obj.pk,
role=role
)
acl.permissions.remove(permission.stored_permission)
if acl.permissions.count() == 0:
acl.delete()