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mirror of https://github.com/netbox-community/netbox.git synced 2024-05-10 07:54:54 +00:00

107 lines
3.4 KiB
Python

from django.conf import settings
from django.db.models import Q
from django.utils.translation import gettext_lazy as _
__all__ = (
'get_permission_for_model',
'permission_is_exempt',
'qs_filter_from_constraints',
'resolve_permission',
'resolve_permission_type',
)
def get_permission_for_model(model, action):
"""
Resolve the named permission for a given model (or instance) and action (e.g. view or add).
:param model: A model or instance
:param action: View, add, change, or delete (string)
"""
# Resolve to the "concrete" model (for proxy models)
model = model._meta.concrete_model
return f'{model._meta.app_label}.{action}_{model._meta.model_name}'
def resolve_permission(name):
"""
Given a permission name, return the app_label, action, and model_name components. For example, "dcim.view_site"
returns ("dcim", "view", "site").
:param name: Permission name in the format <app_label>.<action>_<model>
"""
try:
app_label, codename = name.split('.')
action, model_name = codename.rsplit('_', 1)
except ValueError:
raise ValueError(
_("Invalid permission name: {name}. Must be in the format <app_label>.<action>_<model>").format(name=name)
)
return app_label, action, model_name
def resolve_permission_type(name):
"""
Given a permission name, return the relevant ObjectType and action. For example, "dcim.view_site" returns
(Site, "view").
:param name: Permission name in the format <app_label>.<action>_<model>
"""
from core.models import ObjectType
app_label, action, model_name = resolve_permission(name)
try:
object_type = ObjectType.objects.get_by_natural_key(app_label=app_label, model=model_name)
except ObjectType.DoesNotExist:
raise ValueError(_("Unknown app_label/model_name for {name}").format(name=name))
return object_type, action
def permission_is_exempt(name):
"""
Determine whether a specified permission is exempt from evaluation.
:param name: Permission name in the format <app_label>.<action>_<model>
"""
app_label, action, model_name = resolve_permission(name)
if action == 'view':
if (
# All models (excluding those in EXEMPT_EXCLUDE_MODELS) are exempt from view permission enforcement
'*' in settings.EXEMPT_VIEW_PERMISSIONS and (app_label, model_name) not in settings.EXEMPT_EXCLUDE_MODELS
) or (
# This specific model is exempt from view permission enforcement
f'{app_label}.{model_name}' in settings.EXEMPT_VIEW_PERMISSIONS
):
return True
return False
def qs_filter_from_constraints(constraints, tokens=None):
"""
Construct a Q filter object from an iterable of ObjectPermission constraints.
Args:
tokens: A dictionary mapping string tokens to be replaced with a value.
"""
if tokens is None:
tokens = {}
def _replace_tokens(value, tokens):
if type(value) is list:
return list(map(lambda v: tokens.get(v, v), value))
return tokens.get(value, value)
params = Q()
for constraint in constraints:
if constraint:
params |= Q(**{k: _replace_tokens(v, tokens) for k, v in constraint.items()})
else:
# Found null constraint; permit model-level access
return Q()
return params