| #!/usr/bin/env python |
| # |
| # Copyright 2016 the original author or authors. |
| # |
| # 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. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| # |
| import structlog |
| import io |
| from lxml import etree |
| from lxml.builder import E |
| import netconf.nc_common.error as ncerror |
| from netconf import NSMAP, qmap |
| from utils import elm |
| from twisted.internet.defer import inlineCallbacks, returnValue, Deferred |
| from capabilities import Capabilities |
| from netconf.nc_rpc.rpc_factory import get_rpc_factory_instance |
| from netconf.constants import Constants as C |
| |
| log = structlog.get_logger() |
| |
| |
| class NetconfProtocolError(Exception): pass |
| |
| |
| class NetconfProtocolHandler: |
| def __init__(self, nc_server, nc_conn, session, grpc_client): |
| self.started = True |
| self.conn = nc_conn |
| self.nc_server = nc_server |
| self.grpc_client = grpc_client |
| self.new_framing = False |
| self.capabilities = Capabilities() |
| self.session = session |
| self.exiting = False |
| self.connected = Deferred() |
| self.connected.addCallback(self.nc_server.client_disconnected, |
| self, None) |
| |
| def send_message(self, msg): |
| self.conn.send_msg(C.XML_HEADER + msg, self.new_framing) |
| |
| def receive_message(self): |
| return self.conn.receive_msg_any(self.new_framing) |
| |
| def send_hello(self, caplist, session=None): |
| msg = elm(C.HELLO, attrib={C.XMLNS: NSMAP[C.NC]}) |
| caps = E.capabilities(*[E.capability(x) for x in caplist]) |
| msg.append(caps) |
| |
| if session is not None: |
| msg.append(E(C.SESSION_ID, str(session.session_id))) |
| msg = etree.tostring(msg) |
| log.info("Sending HELLO", msg=msg) |
| msg = msg.decode('utf-8') |
| self.send_message(msg) |
| |
| def send_rpc_reply(self, rpc_reply, origmsg): |
| reply = etree.Element(qmap(C.NC) + C.RPC_REPLY, attrib=origmsg.attrib, |
| nsmap=origmsg.nsmap) |
| try: |
| rpc_reply.getchildren |
| reply.append(rpc_reply) |
| except AttributeError: |
| reply.extend(rpc_reply) |
| ucode = etree.tounicode(reply, pretty_print=True) |
| log.info("RPC-Reply", reply=ucode) |
| self.send_message(ucode) |
| |
| def set_framing_version(self): |
| if C.NETCONF_BASE_11 in self.capabilities.client_caps: |
| self.new_framing = True |
| elif C.NETCONF_BASE_10 not in self.capabilities.client_caps: |
| raise SessionError( |
| "Client doesn't implement 1.0 or 1.1 of netconf") |
| |
| @inlineCallbacks |
| def open_session(self): |
| # The transport should be connected at this point. |
| try: |
| # Send hello message. |
| yield self.send_hello(self.capabilities.server_caps, self.session) |
| # Get reply |
| reply = yield self.receive_message() |
| log.info("reply-received", reply=reply) |
| |
| # Parse reply |
| tree = etree.parse(io.BytesIO(reply.encode('utf-8'))) |
| root = tree.getroot() |
| caps = root.xpath(C.CAPABILITY_XPATH, namespaces=NSMAP) |
| |
| # Store capabilities |
| for cap in caps: |
| self.capabilities.add_client_capability(cap.text) |
| |
| self.set_framing_version() |
| self.session.session_opened = True |
| |
| log.info('session-opened', session_id=self.session.session_id, |
| framing="1.1" if self.new_framing else "1.0") |
| except Exception as e: |
| log.error('hello-failure', exception=repr(e)) |
| self.stop(repr(e)) |
| raise |
| |
| @inlineCallbacks |
| def start(self): |
| log.info('starting') |
| |
| try: |
| yield self.open_session() |
| while True: |
| if not self.session.session_opened: |
| break; |
| msg = yield self.receive_message() |
| yield self.handle_request(msg) |
| |
| except Exception as e: |
| log.exception('exception', exception=repr(e)) |
| self.stop(repr(e)) |
| |
| log.info('shutdown') |
| returnValue(self) |
| |
| @inlineCallbacks |
| def handle_request(self, msg): |
| if not self.session.session_opened: |
| return |
| |
| # Any error with XML encoding here is going to cause a session close |
| try: |
| tree = etree.parse(io.BytesIO(msg.encode('utf-8'))) |
| if not tree: |
| raise ncerror.SessionError(msg, "Invalid XML from client.") |
| except etree.XMLSyntaxError: |
| log.error("malformed-message", msg=msg) |
| try: |
| error = ncerror.BadMsg(msg) |
| self.send_message(error.get_reply_msg()) |
| except AttributeError: |
| log.error("attribute-error", msg=msg) |
| # close session |
| self.close() |
| return |
| |
| rpcs = tree.xpath(C.RPC_XPATH, namespaces=NSMAP) |
| if not rpcs: |
| raise ncerror.SessionError(msg, "No rpc found") |
| |
| # A message can have multiple rpc requests |
| rpc_factory = get_rpc_factory_instance() |
| for rpc in rpcs: |
| try: |
| # Validate message id is received |
| try: |
| msg_id = rpc.get(C.MESSAGE_ID) |
| log.info("Received-rpc-message-id", msg_id=msg_id) |
| except (TypeError, ValueError): |
| log.error('no-message-id', rpc=rpc) |
| raise ncerror.MissingElement(msg, C.MESSAGE_ID) |
| |
| # Get a rpc handler |
| rpc_handler = rpc_factory.get_rpc_handler(rpc, |
| msg, |
| self.grpc_client, |
| self.session) |
| if rpc_handler: |
| # set the parameters for this handler |
| response = yield rpc_handler.execute() |
| log.info('handler', |
| rpc_handler=rpc_handler, |
| is_error=response.is_error, |
| response=response) |
| self.send_rpc_reply(response.node, rpc) |
| if response.close_session: |
| log.info('response-closing-session', response=response) |
| self.close() |
| else: |
| log.error('no-rpc-handler', |
| request=msg, |
| session_id=self.session.session_id) |
| raise ncerror.NotImpl(msg) |
| |
| except ncerror.BadMsg as err: |
| log.info('ncerror.BadMsg') |
| if self.new_framing: |
| self.send_message(err.get_reply_msg()) |
| else: |
| # If we are 1.0 we have to simply close the connection |
| # as we are not allowed to send this error |
| log.error("Closing-1-0-session--malformed-message") |
| self.close() |
| except (ncerror.NotImpl, ncerror.MissingElement) as e: |
| log.info('error', repr(e)) |
| self.send_message(e.get_reply_msg()) |
| except Exception as ex: |
| log.info('Exception', repr(ex)) |
| error = ncerror.ServerException(rpc, ex) |
| self.send_message(error.get_reply_msg()) |
| |
| |
| def stop(self, reason): |
| if not self.exiting: |
| log.debug('stopping') |
| self.exiting = True |
| if self.session.session_opened: |
| # TODO: send a closing message to the far end |
| self.conn.close_connection() |
| self.nc_server.session_mgr.remove_session(self.session) |
| self.session.session_opened = False |
| self.connected.callback(None) |
| log.info('stopped') |
| |
| def close(self): |
| if not self.exiting: |
| log.debug('closing-client') |
| self.exiting = True |
| if self.session.session_opened: |
| self.conn.close_connection() |
| self.nc_server.session_mgr.remove_session(self.session) |
| self.session.session_opened = False |
| self.connected.callback(None) |
| log.info('closing-client') |