# -*- coding: utf-8 -*- {{{
# vim: set fenc=utf-8 ft=python sw=4 ts=4 sts=4 et:
#
# Copyright 2019, 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
#
# 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
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# PACIFIC NORTHWEST NATIONAL LABORATORY operated by
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# }}}
import inspect
import logging
import os
import sys
import traceback
import weakref
import re
import gevent.local
from gevent.event import AsyncResult
from volttron.platform import jsonapi
from volttron.platform.agent.utils import get_messagebus
from .base import SubsystemBase
from ..errors import VIPError
from ..results import counter, ResultsDictionary
from ..decorators import annotate, annotations, dualmethod, spawn
from .... import jsonrpc
from volttron.platform.vip.socket import Message
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__)
def _isregex(obj):
return obj is not None and isinstance(obj, str) and len(obj) > 1 and obj[0] == obj[-1] == '/'
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': list(self.methods)}
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
@staticmethod
def _inspect(method):
response = {'params': {}}
signature = inspect.signature(method)
for p in signature.parameters.values():
response['params'][p.name] = {
'kind': p.kind.name
}
if p.default is not inspect.Parameter.empty:
response['params'][p.name]['default'] = p.default
if p.annotation is not inspect.Parameter.empty:
annotation = p.annotation.__name__ if type(p.annotation) is type else str(p.annotation)
response['params'][p.name]['annotation'] = annotation
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 Exception:
pass
else:
response['source'] = {
'file': source,
'line_number': lineno
}
ret = signature.return_annotation
if ret is not inspect.Signature.empty:
response['return'] = ret.__name__ if type(ret) is type else str(ret)
return response
[docs]class RPC(SubsystemBase):
def __init__(self, core, owner, peerlist_subsys):
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
self._message_bus = self.core().messagebus
self.peerlist_subsystem = peerlist_subsys
self.peer_list = {}
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
# Registering to 'onadd' and 'ondrop' signals to get notified whenever new peer is added/removed
self.peerlist_subsystem.onadd.connect(self._add_new_peer)
self.peerlist_subsystem.ondrop.connect(self._drop_new_peer)
def _disconnected(self, sender, **kwargs):
self._isconnected = False
def _add_new_peer(self, sender, **kwargs):
try:
peer = kwargs.pop('peer')
message_bus = kwargs.pop('message_bus')
self.peer_list[peer] = message_bus
except KeyError:
pass
def _drop_new_peer(self, sender, **kwargs):
try:
peer = kwargs.pop('peer')
self.peer_list.pop(peer)
except KeyError:
pass
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)
if self._message_bus == "rmq":
# When we address issue #2107 external platform user should
# have instance name also included in username.
user = user.split(".")[1]
_log.debug("Current user in checked_method is {}".format(user))
user_capabilites = self._owner.vip.auth.get_capabilities(user)
_log.debug("**user caps is: {}".format(user_capabilites))
if user_capabilites:
user_capabilities_names = set(user_capabilites.keys())
else:
user_capabilities_names = set()
_log.debug("Required caps is : {}".format(required_caps))
_log.debug("user capability names: {}".format(user_capabilities_names))
if not required_caps.issubset(user_capabilities_names):
msg = ('method "{}" requires capabilities {}, but capability {} was'
' provided for user {}').format(method.__name__, required_caps, user_capabilites, user)
raise jsonrpc.exception_from_json(jsonrpc.UNAUTHORIZED, msg)
else:
# Now check if args passed to method are the ones allowed.
for cap_name, param_dict in user_capabilites.items():
if param_dict and required_caps and cap_name in required_caps:
# if the method has required capabilities and
# if the user capability has argument restrictions, check if the args passed to method
# match the requirement
_log.debug("args = {} kwargs= {}".format(args, kwargs))
args_dict = inspect.getcallargs(method, *args, **kwargs)
_log.debug("dict = {}".format(args_dict))
_log.debug("name= {} parameters allowed={}".format(cap_name, param_dict))
for name, value in param_dict.items():
_log.debug("name= {} value={}".format(name, value))
if name not in args_dict:
raise jsonrpc.exception_from_json(jsonrpc.UNAUTHORIZED,
"User {} capability is not defined "
"properly. method {} does not have "
"a parameter {}".format(user, method.__name__, name))
if _isregex(value):
regex = re.compile('^' + value[1:-1] + '$')
if not regex.match(args_dict[name]):
raise jsonrpc.exception_from_json(jsonrpc.UNAUTHORIZED,
"User {} can call method {} only "
"with {} matching pattern {} but called with "
"{}={}".format(user, method.__name__, name, value,
name, args_dict[name]))
elif args_dict[name] != value:
raise jsonrpc.exception_from_json(jsonrpc.UNAUTHORIZED,
"User {} can call method {} only "
"with {}={} but called with "
"{}={}".format(user, method.__name__, name, value,
name, args_dict[name]))
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]
rpc_msg = message.args[1] #jsonapi.loads(message.args[1])
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
for idx, msg in enumerate(message.args):
if isinstance(msg, str):
message.args[idx] = jsonapi.loads(msg)
dispatch = self._dispatcher.dispatch
#_log.debug("External RPC IN message args {}".format(message))
responses = [response for response in (
dispatch(msg, message) for msg in message.args) if response]
#_log.debug("External RPC Responses {}".format(responses))
if responses:
message.user = ''
try:
message.peer = ''
message.subsystem = 'external_rpc'
frames = []
op = '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)
#_log.debug("EXT_RPC subsystem handler OUT message {}".format(message))
try:
self.core().connection.send_vip(peer='',
subsystem='external_rpc',
args=frames,
msg_id=message.id,
user=message.user,
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
if self._message_bus == "rmq":
for idx, msg in enumerate(message.args):
if not isinstance(msg, dict):
message.args[idx] = jsonapi.loads(msg)
responses = [response for response in (
dispatch(msg, message) for msg in message.args) if response]
else:
responses = [response for response in (
dispatch(msg, message) for msg in message.args) if response]
if responses:
message.user = ''
message.args = responses
try:
if self._isconnected:
if self._message_bus == 'zmq':
self.core().connection.send_vip_object(message, copy=False)
else:
# Agent is running on RMQ message bus.
# Adding backward compatibility support for ZMQ. Check if the peer
# is running on ZMQ bus. If yes, send RPC message to proxy router
# agent to forward using ZMQ message bus connection
try:
msg_bus = self.peer_list[message.peer]
except KeyError:
msg_bus = self._message_bus
if msg_bus == 'zmq':
# If peer connected to ZMQ bus, send via proxy router agent
self.core().connection.send_vip_object_via_proxy(message)
else:
self.core().connection.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(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 name is not None and not isinstance(name, str):
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 = ''
if request:
if self._isconnected:
try:
self.core().connection.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 = f'{next(self._counter)}.{hash(result)}'
self._outstanding[ident] = result
subsystem = None
frames = []
if not self._isconnected:
return
if self._message_bus == 'zmq':
if platform == '':#local platform
subsystem = 'RPC'
frames.append(request)
else:
frames = []
op = 'send_platform'
subsystem = 'external_rpc'
frames.append(op)
msg = dict(to_platform=platform, to_peer=peer,
from_platform='', from_peer='', args=[request])
frames.append(msg)
peer = ''
try:
# _log.debug("peer: {0}, subsytem: {1}, args:{2}, id: {3}".format(peer, subsystem,
# args, id))
self.core().connection.send_vip(peer,
subsystem,
args=frames,
msg_id=ident)
except ZMQError as exc:
if exc.errno == ENOTSOCK:
_log.debug("Socket send on non socket {}".format(self.core().identity))
# _log.debug("RPC subsystem: External platform RPC msg: {}".format(frames))
else:
# Agent running on RMQ message bus.
# Adding backward compatibility support for ZMQ. Check if peer
# is running on ZMQ bus. If yes, send RPC message to proxy router agent to
# forward over ZMQ message bus connection
try:
peer_msg_bus = self.peer_list[peer]
except KeyError:
peer_msg_bus = self._message_bus
if peer_msg_bus == 'zmq':
# peer connected to ZMQ bus, send via proxy router agent
self.core().connection.send_via_proxy(peer, 'RPC', msg_id=ident, args=[request])
else:
self.core().connection.send_vip(peer,
'RPC',
args=[request],
msg_id=ident,
platform=platform)
return result
__call__ = call
[docs] def notify(self, peer, method, *args, **kwargs):
platform = kwargs.pop('external_platform', '')
request = self._dispatcher.notify(method, args, kwargs)
frames = []
if not self._isconnected:
return
if self._message_bus == 'zmq':
subsystem = None
if platform == '':
subsystem = 'RPC'
frames.append(request)
else:
op = 'send_platform'
subsystem = 'external_rpc'
frames.append(op)
msg = dict(to_platform=platform, to_peer=peer,
from_platform='', from_peer='', args=[request])
frames.append(msg)
peer = ''
try:
# _log.debug("peer: {0}, subsytem: {1}, args:{2}".format(peer, subsystem,
# frames))
self.core().connection.send_vip(peer,
subsystem,
args=frames)
except ZMQError as exc:
if exc.errno == ENOTSOCK:
_log.debug("Socket send on non socket {}".format(self.core().identity))
else:
# Agent running on RMQ message bus.
# Adding backward compatibility support for ZMQ. Check if peer
# is running on ZMQ bus. If yes, send RPC message to proxy router agent to
# forward over ZMQ message bus connection
try:
peer_msg_bus = self.peer_list[peer]
except KeyError:
#self.peer_list = self.peerlist_subsystem.list_with_messagebus().get(2)
#_log.debug("PEERS: {}".format(self.peer_list))
peer_msg_bus = self._message_bus
if peer_msg_bus == 'zmq':
# peer connected to ZMQ bus, send via proxy router agent
self.core().connection.send_via_proxy(peer,
'RPC',
args=[request])
else:
self.core().connection.send_vip(peer,
'RPC',
args=[request],
platform=platform)
@dualmethod
def allow(self, method, capabilities):
if isinstance(capabilities, str):
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 capabilities can be provided in a list:
.. code-block:: python
@RPC.allow(['can_read_status', 'can_call_my_methods'])
"""
def decorate(method):
if isinstance(capabilities, str):
annotate(method, set, 'rpc.allow_capabilities', capabilities)
else:
for cap in capabilities:
annotate(method, set, 'rpc.allow_capabilities', cap)
return method
return decorate