# -*- coding: utf-8 -*-
import collections
import itertools
from collections import abc
from ..models.model_base import Model, AccessControlledModel, _permissionClauses
from ..exceptions import AccessException
from ..constants import AccessType, TEXT_SCORE_SORT_MAX
from ..utility.model_importer import ModelImporter
[docs]class AccessControlMixin:
"""
This mixin is intended to be used for resources which aren't access
controlled by default, but resolve their access controls through other
resources. As such, the overridden methods retain the same parameters and
only alter functionality related to access control resolution.
resourceColl corresponds to the resource collection that needs to be used
for resolution, for example the Item model has a resourceColl of folder.
resourceParent corresponds to the field in which the parent resource
belongs, so for an item it would be the folderId.
"""
resourceColl = None
resourceParent = None
[docs] def load(self, id, level=AccessType.ADMIN, user=None, objectId=True,
force=False, fields=None, exc=False):
"""
Calls Model.load on the current item, and then attempts to load the
resourceParent which the user must have access to in order to load this
model.
Takes the same parameters as
:py:func:`girder.models.model_base.AccessControlledModel.load`.
"""
loadFields = fields
if not force:
extraFields = {'attachedToId', 'attachedToType'}
if self.resourceParent:
extraFields.add(self.resourceParent)
loadFields = self._supplementFields(fields, extraFields)
doc = Model.load(self, id=id, objectId=objectId, fields=loadFields, exc=exc)
if not force and doc is not None:
if doc.get(self.resourceParent):
loadType = self.resourceColl
loadId = doc[self.resourceParent]
else:
loadType = doc.get('attachedToType')
loadId = doc.get('attachedToId')
if isinstance(loadType, str):
ModelImporter.model(loadType).load(loadId, level=level, user=user, exc=exc)
elif isinstance(loadType, list) and len(loadType) == 2:
ModelImporter.model(*loadType).load(loadId, level=level, user=user, exc=exc)
else:
raise Exception('Invalid model type: %s' % str(loadType))
self._removeSupplementalFields(doc, fields)
return doc
[docs] def hasAccess(self, resource, user=None, level=AccessType.READ):
"""
Determines if a user has access to a resource based on their access to
the resourceParent.
Takes the same parameters as
:py:func:`girder.models.model_base.AccessControlledModel.hasAccess`.
"""
resource = ModelImporter.model(self.resourceColl).load(
resource[self.resourceParent], force=True)
return ModelImporter.model(self.resourceColl).hasAccess(
resource, user=user, level=level)
[docs] def hasAccessFlags(self, doc, user=None, flags=None):
"""
See the documentation of AccessControlledModel.hasAccessFlags, which this wraps.
"""
if not flags:
return True
resource = ModelImporter.model(self.resourceColl).load(doc[self.resourceParent], force=True)
return ModelImporter.model(self.resourceColl).hasAccessFlags(resource, user, flags)
[docs] def requireAccess(self, doc, user=None, level=AccessType.READ):
"""
This wrapper just provides a standard way of throwing an
access denied exception if the access check fails.
"""
if not self.hasAccess(doc, user, level):
if level == AccessType.READ:
perm = 'Read'
elif level == AccessType.WRITE:
perm = 'Write'
elif level in (AccessType.ADMIN, AccessType.SITE_ADMIN):
perm = 'Admin'
else:
perm = 'Unknown level'
if user:
userid = str(user.get('_id', ''))
else:
userid = None
raise AccessException('%s access denied for %s %s (user %s).' %
(perm, self.name, doc.get('_id', 'unknown'),
userid))
[docs] def requireAccessFlags(self, doc, user=None, flags=None):
"""
See the documentation of AccessControlledModel.requireAccessFlags, which this wraps.
"""
if not flags:
return
resource = ModelImporter.model(self.resourceColl).load(doc[self.resourceParent], force=True)
return ModelImporter.model(self.resourceColl).requireAccessFlags(resource, user, flags)
[docs] def filterResultsByPermission(self, cursor, user, level, limit=0, offset=0,
removeKeys=(), flags=None):
"""
Yields filtered results from the cursor based on the access control
existing for the resourceParent.
Takes the same parameters as
:py:func:`girder.models.model_base.AccessControlledModel.filterResultsByPermission`.
"""
# Cache mapping resourceIds -> access granted (bool)
resourceAccessCache = {}
def hasAccess(_result):
resourceId = _result[self.resourceParent]
# return cached check if it exists
if resourceId in resourceAccessCache:
return resourceAccessCache[resourceId]
# if the resourceId is not cached, check for permission "level"
# and set the cache
resource = ModelImporter.model(self.resourceColl).load(resourceId, force=True)
val = ModelImporter.model(self.resourceColl).hasAccess(
resource, user=user, level=level)
if flags:
val = val and ModelImporter.model(self.resourceColl).hasAccessFlags(
resource, user=user, flags=flags)
resourceAccessCache[resourceId] = val
return val
endIndex = offset + limit if limit else None
filteredCursor = filter(hasAccess, cursor)
for result in itertools.islice(filteredCursor, offset, endIndex):
for key in removeKeys:
if key in result:
del result[key]
yield result
def textSearch(self, query, user=None, filters=None, limit=0, offset=0,
sort=None, fields=None, level=AccessType.READ):
filters, fields = self._textSearchFilters(query, filters, fields)
defaultSort = [('_textScore', {'$meta': 'textScore'})]
cursor = self.findWithPermissions(
filters, offset=offset, limit=limit, sort=sort, fields=fields,
user=user, level=level, aggregateSort=defaultSort)
if (sort is None and not getattr(cursor, 'fromAggregate', False)
and callable(getattr(cursor, 'count', None))
and cursor.count() < TEXT_SCORE_SORT_MAX):
cursor = self.findWithPermissions(
filters, offset=offset, limit=limit, sort=defaultSort, fields=fields,
user=user, level=level)
return cursor
[docs] def prefixSearch(self, query, user=None, filters=None, limit=0, offset=0,
sort=None, fields=None, level=AccessType.READ,
prefixSearchFields=None):
"""
Custom override of Model.prefixSearch to also force permission-based
filtering. The parameters are the same as Model.prefixSearch.
:param user: The user to apply permission filtering for.
:type user: dict or None
:param level: The access level to require.
:type level: girder.constants.AccessType
"""
filters = self._prefixSearchFilters(query, filters, prefixSearchFields)
return self.findWithPermissions(
filters, offset=offset, limit=limit, sort=sort, fields=fields,
user=user, level=level)
def permissionClauses(self, user=None, level=None, prefix=''):
return _permissionClauses(user, level, prefix)
def _findWithPermissionsFallback(self, query, offset, limit, timeout,
fields, sort, user, level, **kwargs):
"""
See findWithPermissions. This is called if Mongo doesn't support
appropriate aggregations or find is used on a model that uses an
acl-mixin model as its parent and therefore needs multiple steps to
reach the owner of the access control list.
See findWithPermissions for parameters and return.
"""
removeKeys = ()
if (fields and any(fields[key] is True for key in fields)
and not fields.get(self.resourceParent)):
fields = fields.copy()
fields[self.resourceParent] = True
removeKeys = (self.resourceParent, )
cursor = self.find(query, timeout=timeout, fields=fields, sort=sort, **kwargs)
result = self.filterResultsByPermission(
cursor=cursor, user=user, level=level, limit=limit, offset=offset,
removeKeys=removeKeys)
if not hasattr(result, 'count'):
origResult, origSelf = result, self
class ResultWithCount:
def count(self):
cursor = origSelf.find(
query, timeout=timeout, fields=fields, sort=sort, **kwargs)
result = origSelf.filterResultsByPermission(
cursor=cursor, user=user, level=level, limit=limit, offset=offset,
removeKeys=removeKeys)
return len(list(result))
def __iter__(self):
return self
def __next__(self):
return next(origResult)
next = __next__
result = ResultWithCount()
return result
[docs] def findWithPermissions(self, query=None, offset=0, limit=0, timeout=None, fields=None,
sort=None, user=None, level=AccessType.READ, aggregateSort=None,
**kwargs):
"""
Search the collection by a set of parameters, only returning results
that the combined user and level have permission to access. Passes any
extra kwargs through to the underlying pymongo.collection.find
function.
:param query: The search query (see general MongoDB docs for "find()")
:type query: dict
:param offset: The offset into the results
:type offset: int
:param limit: Maximum number of documents to return
:type limit: int
:param timeout: Cursor timeout in ms. Default is no timeout.
:type timeout: int
:param fields: A mask for filtering result documents by key, or None to return the full
document, passed to MongoDB find() as the `projection` param.
:type fields: `str, list of strings or tuple of strings for fields to be included from the
document, or dict for an inclusion or exclusion projection`.
:param sort: The sort order.
:type sort: List of (key, order) tuples.
:param user: The user to check policies against.
:type user: dict or None
:param level: The access level. Explicitly passing None skips doing
permissions checks.
:type level: AccessType
:param aggregateSort: A sort order to use if `sort` is None and an
aggregation is used.
:type aggregateSort: List of (key, order) tuples.
:returns: A pymongo Cursor, CommandCursor, or an iterable. If a
CommandCursor, it has been augmented with a count function.
"""
if level is not None and (not user or not user['admin']):
# If the resourceColl isn't an access controlled model that we
# know how to reach, fall back to performing the ordinary query and
# then filtering it by permission. For instance, if a model uses
# the acl mixin to get acl from a model that itself uses the acl
# mixin, this will return the correct results, but without the
# utility of being able perform count().
# Note, this also handles models which use attachedToType and
# attachedToId, since ModelImporter.model(None) will not be an access
# controlled model.
if not isinstance(ModelImporter.model(self.resourceColl), AccessControlledModel):
return self._findWithPermissionsFallback(
query, offset, limit, timeout, fields, sort, user, level,
**kwargs)
query = query or {}
initialPipeline = [
{'$match': query},
{'$lookup': {
'from': self.resourceColl,
'localField': self.resourceParent,
'foreignField': '_id',
'as': '__parent'
}},
{'$match': self.permissionClauses(user, level, '__parent.')},
]
countPipeline = initialPipeline + [
{'$count': 'count'},
]
fullPipeline = initialPipeline + [
{'$project': {'__parent': False}},
]
if sort is not None or aggregateSort is not None:
fullPipeline.append({'$sort': collections.OrderedDict(sort or aggregateSort)})
# limit should immediately follow sort for efficiency
if limit:
fullPipeline.append({'$limit': limit + (offset or 0)})
if offset:
fullPipeline.append({'$skip': offset})
if fields is not None:
# fields can be a Sequence, Set, or Mapping. If a Mapping, the
# values are typically booleans or themselves a mapping (such
# as from text search to add a field like _textScore: {$meta:
# 'textScore'}). Convert sequences and sets to mappings (as
# done in pymongo), then use values that aren't themselves
# mappings as a projection and those that are mappings as
# added fields.
if isinstance(fields, (abc.Sequence, abc.Set)):
fields = dict.fromkeys(fields, 1)
if any(not isinstance(v, abc.Mapping) for v in fields.values()):
fullPipeline.append({'$project': {
k: v for k, v in fields.items()
if not isinstance(v, abc.Mapping)}})
if any(isinstance(v, abc.Mapping) for v in fields.values()):
fullPipeline.append({'$addFields': {
k: v for k, v in fields.items()
if isinstance(v, abc.Mapping)}})
options = {
# By allowing disk use, large sorted queries will work. If
# disallowed, they will fail. Although this is slower than
# memory sorting, actual experiemnts show it to be acceptable
'allowDiskUse': True,
# Start with a 0-sized batch. This avoids fetching data from
# the Mongo server if the query is never polled and starts
# streaming data faster than a fixed batch size.
'cursor': {'batchSize': 0}
}
if timeout:
options['maxTimeMS'] = timeout
result = self.collection.aggregate(fullPipeline, **options)
def count():
try:
return next(iter(self.collection.aggregate(countPipeline, **options)))['count']
except StopIteration:
# If there are no values, this won't return the count, in
# which case it is zero.
return 0
result.count = count
# Mark that this result came from an aggregate. If an aggregate
# is used, the results could be sorted via the aggregateSort
# parameter. This informs the consumer of the result.
result.fromAggregate = True
return result
return self.find(query, offset, limit, timeout, fields, sort, **kwargs)