datatracker/permissions/utils.py
2010-11-02 16:11:59 +00:00

666 lines
19 KiB
Python

# django imports
from django.db import IntegrityError
from django.db.models import Q
from django.db import connection
from django.contrib.auth.models import User
from django.contrib.auth.models import Group
from django.contrib.contenttypes.models import ContentType
from django.core.cache import cache
from django.core.exceptions import ObjectDoesNotExist
# permissions imports
from permissions.exceptions import Unauthorized
from permissions.models import ObjectPermission
from permissions.models import ObjectPermissionInheritanceBlock
from permissions.models import Permission
from permissions.models import PrincipalRoleRelation
from permissions.models import Role
# Roles ######################################################################
def add_role(principal, role):
"""Adds a global role to a principal.
**Parameters:**
principal
The principal (user or group) which gets the role added.
role
The role which is assigned.
"""
if isinstance(principal, User):
try:
ppr = PrincipalRoleRelation.objects.get(user=principal, role=role, content_id=None, content_type=None)
except PrincipalRoleRelation.DoesNotExist:
PrincipalRoleRelation.objects.create(user=principal, role=role)
return True
else:
try:
ppr = PrincipalRoleRelation.objects.get(group=principal, role=role, content_id=None, content_type=None)
except PrincipalRoleRelation.DoesNotExist:
PrincipalRoleRelation.objects.create(group=principal, role=role)
return True
return False
def add_local_role(obj, principal, role):
"""Adds a local role to a principal.
**Parameters:**
obj
The object for which the principal gets the role.
principal
The principal (user or group) which gets the role.
role
The role which is assigned.
"""
ctype = ContentType.objects.get_for_model(obj)
if isinstance(principal, User):
try:
ppr = PrincipalRoleRelation.objects.get(user=principal, role=role, content_id=obj.pk, content_type=ctype)
except PrincipalRoleRelation.DoesNotExist:
PrincipalRoleRelation.objects.create(user=principal, role=role, content=obj)
return True
else:
try:
ppr = PrincipalRoleRelation.objects.get(group=principal, role=role, content_id=obj.pk, content_type=ctype)
except PrincipalRoleRelation.DoesNotExist:
PrincipalRoleRelation.objects.create(group=principal, role=role, content=obj)
return True
return False
def remove_role(principal, role):
"""Removes role from passed principal.
**Parameters:**
principal
The principal (user or group) from which the role is removed.
role
The role which is removed.
"""
try:
if isinstance(principal, User):
ppr = PrincipalRoleRelation.objects.get(
user=principal, role=role, content_id=None, content_type=None)
else:
ppr = PrincipalRoleRelation.objects.get(
group=principal, role=role, content_id=None, content_type=None)
except PrincipalRoleRelation.DoesNotExist:
return False
else:
ppr.delete()
return True
def remove_local_role(obj, principal, role):
"""Removes role from passed object and principle.
**Parameters:**
obj
The object from which the role is removed.
principal
The principal (user or group) from which the role is removed.
role
The role which is removed.
"""
try:
ctype = ContentType.objects.get_for_model(obj)
if isinstance(principal, User):
ppr = PrincipalRoleRelation.objects.get(
user=principal, role=role, content_id=obj.pk, content_type=ctype)
else:
ppr = PrincipalRoleRelation.objects.get(
group=principal, role=role, content_id=obj.pk, content_type=ctype)
except PrincipalRoleRelation.DoesNotExist:
return False
else:
ppr.delete()
return True
def remove_roles(principal):
"""Removes all roles passed principal (user or group).
**Parameters:**
principal
The principal (user or group) from which all roles are removed.
"""
if isinstance(principal, User):
ppr = PrincipalRoleRelation.objects.filter(
user=principal, content_id=None, content_type=None)
else:
ppr = PrincipalRoleRelation.objects.filter(
group=principal, content_id=None, content_type=None)
if ppr:
ppr.delete()
return True
else:
return False
def remove_local_roles(obj, principal):
"""Removes all local roles from passed object and principal (user or
group).
**Parameters:**
obj
The object from which the roles are removed.
principal
The principal (user or group) from which the roles are removed.
"""
ctype = ContentType.objects.get_for_model(obj)
if isinstance(principal, User):
ppr = PrincipalRoleRelation.objects.filter(
user=principal, content_id=obj.pk, content_type=ctype)
else:
ppr = PrincipalRoleRelation.objects.filter(
group=principal, content_id=obj.pk, content_type=ctype)
if ppr:
ppr.delete()
return True
else:
return False
def get_roles(user, obj=None):
"""Returns *all* roles of the passed user.
This takes direct roles and roles via the user's groups into account.
If an object is passed local roles will also added. Then all local roles
from all ancestors and all user's groups are also taken into account.
This is the method to use if one want to know whether the passed user
has a role in general (for the passed object).
**Parameters:**
user
The user for which the roles are returned.
obj
The object for which local roles will returned.
"""
roles = []
groups = user.groups.all()
groups_ids_str = ", ".join([str(g.id) for g in groups])
# Gobal roles for user and the user's groups
cursor = connection.cursor()
cursor.execute("""SELECT role_id
FROM permissions_principalrolerelation
WHERE (user_id=%s OR group_id IN (%s))
AND content_id is Null""" % (user.id, groups_ids_str))
for row in cursor.fetchall():
roles.append(row[0])
# Local roles for user and the user's groups and all ancestors of the
# passed object.
while obj:
ctype = ContentType.objects.get_for_model(obj)
cursor.execute("""SELECT role_id
FROM permissions_principalrolerelation
WHERE (user_id='%s' OR group_id IN (%s))
AND content_id='%s'
AND content_type_id='%s'""" % (user.id, groups_ids_str, obj.pk, ctype.id))
for row in cursor.fetchall():
roles.append(row[0])
try:
obj = obj.get_parent_for_permissions()
except AttributeError:
obj = None
return roles
def get_global_roles(principal):
"""Returns *direct* global roles of passed principal (user or group).
"""
if isinstance(principal, User):
return [prr.role for prr in PrincipalRoleRelation.objects.filter(
user=principal, content_id=None, content_type=None)]
else:
if isinstance(principal, Group):
principal = (principal,)
return [prr.role for prr in PrincipalRoleRelation.objects.filter(
group__in=principal, content_id=None, content_type=None)]
def get_local_roles(obj, principal):
"""Returns *direct* local roles for passed principal and content object.
"""
ctype = ContentType.objects.get_for_model(obj)
if isinstance(principal, User):
return [prr.role for prr in PrincipalRoleRelation.objects.filter(
user=principal, content_id=obj.pk, content_type=ctype)]
else:
return [prr.role for prr in PrincipalRoleRelation.objects.filter(
group=principal, content_id=obj.pk, content_type=ctype)]
# Permissions ################################################################
def check_permission(obj, user, codename, roles=None):
"""Checks whether passed user has passed permission for passed obj.
**Parameters:**
obj
The object for which the permission should be checked.
codename
The permission's codename which should be checked.
user
The user for which the permission should be checked.
roles
If given these roles will be assigned to the user temporarily before
the permissions are checked.
"""
if not has_permission(obj, user, codename):
raise Unauthorized("User '%s' doesn't have permission '%s' for object '%s' (%s)"
% (user, codename, obj.slug, obj.__class__.__name__))
def grant_permission(obj, role, permission):
"""Grants passed permission to passed role. Returns True if the permission
was able to be added, otherwise False.
**Parameters:**
obj
The content object for which the permission should be granted.
role
The role for which the permission should be granted.
permission
The permission which should be granted. Either a permission
object or the codename of a permission.
"""
if not isinstance(permission, Permission):
try:
permission = Permission.objects.get(codename = permission)
except Permission.DoesNotExist:
return False
ct = ContentType.objects.get_for_model(obj)
try:
ObjectPermission.objects.get(role=role, content_type = ct, content_id=obj.pk, permission=permission)
except ObjectPermission.DoesNotExist:
ObjectPermission.objects.create(role=role, content=obj, permission=permission)
return True
def remove_permission(obj, role, permission):
"""Removes passed permission from passed role and object. Returns True if
the permission has been removed.
**Parameters:**
obj
The content object for which a permission should be removed.
role
The role for which a permission should be removed.
permission
The permission which should be removed. Either a permission object
or the codename of a permission.
"""
if not isinstance(permission, Permission):
try:
permission = Permission.objects.get(codename = permission)
except Permission.DoesNotExist:
return False
ct = ContentType.objects.get_for_model(obj)
try:
op = ObjectPermission.objects.get(role=role, content_type = ct, content_id=obj.pk, permission = permission)
except ObjectPermission.DoesNotExist:
return False
op.delete()
return True
def has_permission(obj, user, codename, roles=None):
"""Checks whether the passed user has passed permission for passed object.
**Parameters:**
obj
The object for which the permission should be checked.
codename
The permission's codename which should be checked.
request
The current request.
roles
If given these roles will be assigned to the user temporarily before
the permissions are checked.
"""
cache_key = "%s-%s-%s" % (obj.content_type, obj.pk, codename)
result = _get_cached_permission(user, cache_key)
if result is not None:
return result
if roles is None:
roles = []
if user.is_superuser:
return True
if not user.is_anonymous():
roles.extend(get_roles(user, obj))
ct = ContentType.objects.get_for_model(obj)
result = False
while obj is not None:
p = ObjectPermission.objects.filter(
content_type=ct, content_id=obj.pk, role__in=roles, permission__codename = codename).values("id")
if len(p) > 0:
result = True
break
if is_inherited(obj, codename) == False:
result = False
break
try:
obj = obj.get_parent_for_permissions()
ct = ContentType.objects.get_for_model(obj)
except AttributeError:
result = False
break
_cache_permission(user, cache_key, result)
return result
# Inheritance ################################################################
def add_inheritance_block(obj, permission):
"""Adds an inheritance for the passed permission on the passed obj.
**Parameters:**
permission
The permission for which an inheritance block should be added.
Either a permission object or the codename of a permission.
obj
The content object for which an inheritance block should be added.
"""
if not isinstance(permission, Permission):
try:
permission = Permission.objects.get(codename = permission)
except Permission.DoesNotExist:
return False
ct = ContentType.objects.get_for_model(obj)
try:
ObjectPermissionInheritanceBlock.objects.get(content_type = ct, content_id=obj.pk, permission=permission)
except ObjectPermissionInheritanceBlock.DoesNotExist:
try:
result = ObjectPermissionInheritanceBlock.objects.create(content=obj, permission=permission)
except IntegrityError:
return False
return True
def remove_inheritance_block(obj, permission):
"""Removes a inheritance block for the passed permission from the passed
object.
**Parameters:**
obj
The content object for which an inheritance block should be added.
permission
The permission for which an inheritance block should be removed.
Either a permission object or the codename of a permission.
"""
if not isinstance(permission, Permission):
try:
permission = Permission.objects.get(codename = permission)
except Permission.DoesNotExist:
return False
ct = ContentType.objects.get_for_model(obj)
try:
opi = ObjectPermissionInheritanceBlock.objects.get(content_type = ct, content_id=obj.pk, permission=permission)
except ObjectPermissionInheritanceBlock.DoesNotExist:
return False
opi.delete()
return True
def is_inherited(obj, codename):
"""Returns True if the passed permission is inherited for passed object.
**Parameters:**
obj
The content object for which the permission should be checked.
codename
The permission which should be checked. Must be the codename of
the permission.
"""
ct = ContentType.objects.get_for_model(obj)
try:
ObjectPermissionInheritanceBlock.objects.get(
content_type=ct, content_id=obj.pk, permission__codename = codename)
except ObjectDoesNotExist:
return True
else:
return False
def get_group(id):
"""Returns the group with passed id or None.
"""
try:
return Group.objects.get(pk=id)
except Group.DoesNotExist:
return None
def get_role(id):
"""Returns the role with passed id or None.
"""
try:
return Role.objects.get(pk=id)
except Role.DoesNotExist:
return None
def get_user(id):
"""Returns the user with passed id or None.
"""
try:
return User.objects.get(pk=id)
except User.DoesNotExist:
return None
def has_group(user, group):
"""Returns True if passed user has passed group.
"""
if isinstance(group, str):
group = Group.objects.get(name=group)
return group in user.groups.all()
def reset(obj):
"""Resets all permissions and inheritance blocks of passed object.
"""
ctype = ContentType.objects.get_for_model(obj)
ObjectPermissionInheritanceBlock.objects.filter(content_id=obj.pk, content_type=ctype).delete()
ObjectPermission.objects.filter(content_id=obj.pk, content_type=ctype).delete()
# Registering ################################################################
def register_permission(name, codename, ctypes=[]):
"""Registers a permission to the framework. Returns the permission if the
registration was successfully, otherwise False.
**Parameters:**
name
The unique name of the permission. This is displayed to the
customer.
codename
The unique codename of the permission. This is used internally to
identify the permission.
content_types
The content type for which the permission is active. This can be
used to display only reasonable permissions for an object. This
must be a Django ContentType
"""
try:
p = Permission.objects.create(name=name, codename=codename)
ctypes = [ContentType.objects.get_for_model(ctype) for ctype in ctypes]
if ctypes:
p.content_types = ctypes
p.save()
except IntegrityError:
return False
return p
def unregister_permission(codename):
"""Unregisters a permission from the framework
**Parameters:**
codename
The unique codename of the permission.
"""
try:
permission = Permission.objects.get(codename=codename)
except Permission.DoesNotExist:
return False
permission.delete()
return True
def register_role(name):
"""Registers a role with passed name to the framework. Returns the new
role if the registration was successfully, otherwise False.
**Parameters:**
name
The unique role name.
"""
try:
role = Role.objects.create(name=name)
except IntegrityError:
return False
return role
def unregister_role(name):
"""Unregisters the role with passed name.
**Parameters:**
name
The unique role name.
"""
try:
role = Role.objects.get(name=name)
except Role.DoesNotExist:
return False
role.delete()
return True
def register_group(name):
"""Registers a group with passed name to the framework. Returns the new
group if the registration was successfully, otherwise False.
Actually this creates just a default Django Group.
**Parameters:**
name
The unique group name.
"""
try:
group = Group.objects.create(name=name)
except IntegrityError:
return False
return group
def unregister_group(name):
"""Unregisters the group with passed name. Returns True if the
unregistration was succesfull otherwise False.
Actually this deletes just a default Django Group.
**Parameters:**
name
The unique role name.
"""
try:
group = Group.objects.get(name=name)
except Group.DoesNotExist:
return False
group.delete()
return True
def _cache_permission(user, cache_key, data):
"""Stores the passed data on the passed user object.
**Parameters:**
user
The user on which the data is stored.
cache_key
The key under which the data is stored.
data
The data which is stored.
"""
if not getattr(user, "permissions", None):
user.permissions = {}
user.permissions[cache_key] = data
def _get_cached_permission(user, cache_key):
"""Returns the stored data from passed user object for passed cache_key.
**Parameters:**
user
The user from which the data is retrieved.
cache_key
The key under which the data is stored.
"""
permissions = getattr(user, "permissions", None)
if permissions:
return user.permissions.get(cache_key, None)