# -*- coding: utf-8 -*- {{{
# vim: set fenc=utf-8 ft=python sw=4 ts=4 sts=4 et:
#
# Copyright 2017, Battelle Memorial Institute.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
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# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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#
# This material was prepared as an account of work sponsored by an agency of
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# employees, nor any jurisdiction or organization that has cooperated in the
# development of these materials, makes any warranty, express or
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# PACIFIC NORTHWEST NATIONAL LABORATORY operated by
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# under Contract DE-AC05-76RL01830
# }}}
from __future__ import absolute_import
import inspect
import logging
import os
import sys
import traceback
import weakref
import gevent.local
from gevent.event import AsyncResult
from volttron.platform.agent import json as jsonapi
from .base import SubsystemBase
from ..errors import VIPError
from ..results import counter, ResultsDictionary
from ..decorators import annotate, annotations, dualmethod, spawn
from .... import jsonrpc
from zmq import Frame, NOBLOCK, ZMQError, EINVAL, EHOSTUNREACH
from zmq.green import ENOTSOCK
__all__ = ['RPC']
_ROOT_PACKAGE_PATH = os.path.dirname(
__import__(__name__.split('.', 1)[0]).__path__[-1]) + os.sep
_log = logging.getLogger(__name__)
class Dispatcher(jsonrpc.Dispatcher):
def __init__(self, methods, local):
super(Dispatcher, self).__init__()
self.methods = methods
self.local = local
self._results = ResultsDictionary()
def serialize(self, json_obj):
return jsonapi.dumps(json_obj)
def deserialize(self, json_string):
return jsonapi.loads(json_string)
def batch_call(self, requests):
methods = []
results = []
for notify, method, args, kwargs in requests:
if notify:
ident = None
else:
result = next(self._results)
ident = result.ident
results.append(result)
methods.append((ident, method, args, kwargs))
return super(Dispatcher, self).batch_call(methods), results
def call(self, method, args=None, kwargs=None):
# pylint: disable=arguments-differ
result = next(self._results)
return super(Dispatcher, self).call(
result.ident, method, args, kwargs), result
def result(self, response, ident, value, context=None):
try:
result = self._results.pop(ident)
except KeyError:
return
result.set(value)
def error(self, response, ident, code, message, data=None, context=None):
try:
result = self._results.pop(ident)
except KeyError:
return
result.set_exception(jsonrpc.exception_from_json(code, message, data))
def exception(self, response, ident, message, context=None):
# XXX: Should probably wrap exception in RPC specific error
# rather than re-raising.
exc_type, exc, exc_tb = sys.exc_info() # pylint: disable=unused-variable
try:
result = self._results.pop(ident)
except KeyError:
return
result.set_exception(exc)
def method(self, request, ident, name, args, kwargs,
batch=None, context=None):
if kwargs:
try:
args, kwargs = kwargs['*args'], kwargs['**kwargs']
except KeyError:
pass
try:
method = self.methods[name]
except KeyError:
if name == 'inspect':
return {'methods': self.methods.keys()}
elif name.endswith('.inspect'):
try:
method = self.methods[name[:-8]]
except KeyError:
pass
else:
return self._inspect(method)
raise NotImplementedError(name)
local = self.local
local.vip_message = context
local.request = request
local.batch = batch
try:
return method(*args, **kwargs)
except Exception as exc: # pylint: disable=broad-except
exc_tb = traceback.format_exc()
_log.error('unhandled exception in JSON-RPC method %r: \n%s',
name, exc_tb)
if getattr(method, 'traceback', True):
exc.exc_info = {'exc_tb': exc_tb}
raise
finally:
del local.vip_message
del local.request
del local.batch
def _inspect(self, method):
params = inspect.getargspec(method)
if hasattr(method, 'im_self'):
params.args.pop(0)
response = {'params': params}
doc = inspect.getdoc(method)
if doc:
response['doc'] = doc
try:
source = inspect.getsourcefile(method)
cut = len(os.path.commonprefix([_ROOT_PACKAGE_PATH, source]))
source = source[cut:]
lineno = inspect.getsourcelines(method)[1]
except IOError:
pass
else:
response['source'] = source, lineno
try:
# pylint: disable=protected-access
response['return'] = method._returns
except AttributeError:
pass
return response
[docs]class RPC(SubsystemBase):
def __init__(self, core, owner):
self.core = weakref.ref(core)
self._owner = owner
self.context = None
self._exports = {}
self._dispatcher = None
self._counter = counter()
self._outstanding = weakref.WeakValueDictionary()
core.register('RPC', self._handle_subsystem, self._handle_error)
core.register('external_rpc', self._handle_external_rpc_subsystem, self._handle_error)
self._isconnected = True
def export(member): # pylint: disable=redefined-outer-name
for name in annotations(member, set, 'rpc.exports'):
self._exports[name] = member
inspect.getmembers(owner, export)
def setup(sender, **kwargs):
# pylint: disable=unused-argument
self.context = gevent.local.local()
self._dispatcher = Dispatcher(self._exports, self.context)
core.onsetup.connect(setup, self)
core.ondisconnected.connect(self._disconnected)
core.onconnected.connect(self._connected)
self._iterate_exports()
def _connected(self, sender, **kwargs):
self._isconnected =True
def _disconnected(self, sender, **kwargs):
self._isconnected = False
def _iterate_exports(self):
'''Iterates over exported methods and adds authorization checks
as necessary
'''
for method_name in self._exports:
method = self._exports[method_name]
caps = annotations(method, set, 'rpc.allow_capabilities')
if caps:
self._exports[method_name] = self._add_auth_check(method, caps)
def _add_auth_check(self, method, required_caps):
'''Adds an authorization check to verify the calling agent has the
required capabilities.
'''
def checked_method(*args, **kwargs):
user = str(self.context.vip_message.user)
caps = self._owner.vip.auth.get_capabilities(user)
if not required_caps <= set(caps):
msg = ('method "{}" requires capabilities {},'
' but capability list {} was'
' provided').format(method.__name__, required_caps, caps)
raise jsonrpc.exception_from_json(jsonrpc.UNAUTHORIZED, msg)
return method(*args, **kwargs)
return checked_method
@spawn
def _handle_external_rpc_subsystem(self, message):
ret_msg = dict()
#_log.debug("EXT_RPC subsystem handler IN message {0}".format(message))
op = message.args[0].bytes
rpc_msg = jsonapi.loads(message.args[1].bytes)
try:
#_log.debug("EXT_RPC subsystem handler IN message {0}, {1}".format(message.peer, rpc_msg))
method_args = rpc_msg['args']
#message.args = [method_args]
message.args = method_args
dispatch = self._dispatcher.dispatch
#_log.debug("External RPC IN message args {}".format(message))
responses = [response for response in (
dispatch(bytes(msg), message) for msg in message.args) if response]
#_log.debug("External RPC Resonses {}".format(responses))
if responses:
message.user = ''
try:
message.peer = ''
message.subsystem = 'external_rpc'
frames = []
op = b'send_platform'
frames.append(op)
msg = jsonapi.dumps(dict(to_platform=rpc_msg['from_platform'],
to_peer=rpc_msg['from_peer'],
from_platform=rpc_msg['to_platform'],
from_peer=rpc_msg['to_peer'], args=responses))
frames.append(msg)
except KeyError:
_log.error("External RPC message did not contain proper message format")
message.args = jsonapi.dumps(ret_msg)
ret_msg = jsonapi.dumps(ret_msg)
#_log.debug("EXT_RPC subsystem handler OUT message {}".format(message))
try:
self.core().socket.send_vip(b'', 'external_rpc', frames,
user=message.user, msg_id=message.id, copy=False)
except ZMQError as ex:
_log.error("ZMQ error: {}".format(ex))
pass
except KeyError:
pass
@spawn
def _handle_subsystem(self, message):
dispatch = self._dispatcher.dispatch
responses = [response for response in (
dispatch(bytes(msg), message) for msg in message.args) if response]
if responses:
message.user = ''
message.args = responses
try:
if self._isconnected:
self.core().socket.send_vip_object(message, copy=False)
except ZMQError as exc:
if exc.errno == ENOTSOCK:
_log.debug("Socket send on non socket {}".format(self.core().identity))
def _handle_error(self, sender, message, error, **kwargs):
result = self._outstanding.pop(bytes(message.id), None)
if isinstance(result, AsyncResult):
result.set_exception(error)
elif result:
for result in result:
result.set_exception(error)
@dualmethod
def export(self, method, name=None):
self._exports[name or method.__name__] = method
return method
[docs] @export.classmethod
def export(cls, name=None): # pylint: disable=no-self-argument
if not isinstance(name, basestring):
method, name = name, name.__name__
annotate(method, set, 'rpc.exports', name)
return method
def decorate(method):
annotate(method, set, 'rpc.exports', name)
return method
return decorate
[docs] def batch(self, peer, requests):
request, results = self._dispatcher.batch_call(requests)
if results:
items = weakref.WeakSet(results)
ident = '%s.%s' % (next(self._counter), id(items))
for result in results:
result._weak_set = items # pylint: disable=protected-access
self._outstanding[ident] = items
else:
ident = b''
if request:
if self._isconnected:
try:
self.core().socket.send_vip(peer, 'RPC', [request], msg_id=ident)
except ZMQError as exc:
if exc.errno == ENOTSOCK:
_log.debug("Socket send on non socket {}".format(self.core().identity))
return results or None
[docs] def call(self, peer, method, *args, **kwargs):
platform = kwargs.pop('external_platform', '')
request, result = self._dispatcher.call(method, args, kwargs)
ident = '%s.%s' % (next(self._counter), hash(result))
self._outstanding[ident] = result
if platform == '':
if self._isconnected:
try:
self.core().socket.send_vip(peer, 'RPC', [request], msg_id=ident)
except ZMQError as exc:
if exc.errno == ENOTSOCK:
_log.debug("Socket send on non socket {}".format(self.core().identity))
else:
frames = []
op = b'send_platform'
frames.append(op)
msg = jsonapi.dumps(dict(to_platform=platform, to_peer=peer,
from_platform='', from_peer='', args=[request]))
frames.append(msg)
#_log.debug("RPC subsystem: External platform RPC msg: {}".format(frames))
if self._isconnected:
try:
self.core().socket.send_vip('', 'external_rpc', frames, msg_id=ident)
except ZMQError as exc:
if exc.errno == ENOTSOCK:
_log.debug("Socket send on non socket {}".format(self.core().identity))
return result
__call__ = call
#__call__ = call
[docs] def notify(self, peer, method, *args, **kwargs):
platform = kwargs.pop('external_platform', '')
request = self._dispatcher.notify(method, args, kwargs)
if platform == '':
if self._isconnected:
try:
self.core().socket.send_vip(peer, 'RPC', [request])
except ZMQError as exc:
if exc.errno == ENOTSOCK:
_log.debug("Socket send on non socket {}".format(self.core().identity))
else:
frames = []
op = b'send_platform'
frames.append(op)
msg = jsonapi.dumps(dict(to_platform=platform, to_peer=peer,
from_platform='', from_peer='', args=[request]))
frames.append(msg)
# _log.debug("RPC subsystem: External platform RPC msg: {}".format(frames))
if self._isconnected:
try:
self.core().socket.send_vip('', 'extrenal_rpc', frames)
except ZMQError as exc:
if exc.errno == ENOTSOCK:
_log.debug("Socket send on non socket {}".format(self.core().identity))
@dualmethod
def allow(self, method, capabilities):
if isinstance(capabilities, basestring):
cap = set([capabilities])
else:
cap = set(capabilities)
self._exports[method.__name__] = self._add_auth_check(method, cap)
[docs] @allow.classmethod
def allow(cls, capabilities):
"""
Decorator specifies required agent capabilities to call a method.
This is designed to be used with the export decorator:
.. code-block:: python
@RPC.export
@RPC.allow('can_read_status')
def get_status():
...
Multiple capabilies can be provided in a list:
.. code-block:: python
@RPC.allow(['can_read_status', 'can_call_my_methods'])
"""
def decorate(method):
if isinstance(capabilities, basestring):
annotate(method, set, 'rpc.allow_capabilities', capabilities)
else:
for cap in capabilities:
annotate(method, set, 'rpc.allow_capabilities', cap)
return method
return decorate