root / ncclient / transport / session.py @ 564bee4f
History | View | Annotate | Download (8 kB)
1 | d095a59e | Shikhar Bhushan | # Copyright 2009 Shikhar Bhushan
|
---|---|---|---|
2 | d095a59e | Shikhar Bhushan | #
|
3 | d095a59e | Shikhar Bhushan | # Licensed under the Apache License, Version 2.0 (the "License");
|
4 | d095a59e | Shikhar Bhushan | # you may not use this file except in compliance with the License.
|
5 | d095a59e | Shikhar Bhushan | # You may obtain a copy of the License at
|
6 | d095a59e | Shikhar Bhushan | #
|
7 | d095a59e | Shikhar Bhushan | # http://www.apache.org/licenses/LICENSE-2.0
|
8 | d095a59e | Shikhar Bhushan | #
|
9 | d095a59e | Shikhar Bhushan | # Unless required by applicable law or agreed to in writing, software
|
10 | d095a59e | Shikhar Bhushan | # distributed under the License is distributed on an "AS IS" BASIS,
|
11 | d095a59e | Shikhar Bhushan | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
12 | d095a59e | Shikhar Bhushan | # See the License for the specific language governing permissions and
|
13 | d095a59e | Shikhar Bhushan | # limitations under the License.
|
14 | d095a59e | Shikhar Bhushan | |
15 | d6688264 | Shikhar Bhushan | from Queue import Queue |
16 | 4de03d63 | Shikhar Bhushan | from threading import Thread, Lock, Event |
17 | e91a5349 | Shikhar Bhushan | |
18 | 57b5f922 | Shikhar Bhushan | from ncclient import xml_ |
19 | 2f8bc438 | Shikhar Bhushan | from ncclient.capabilities import Capabilities |
20 | d095a59e | Shikhar Bhushan | |
21 | 66cd54c8 | Shikhar Bhushan | from errors import TransportError |
22 | 66cd54c8 | Shikhar Bhushan | |
23 | 41e2ed46 | Shikhar Bhushan | import logging |
24 | 41e2ed46 | Shikhar Bhushan | logger = logging.getLogger('ncclient.transport.session')
|
25 | 41e2ed46 | Shikhar Bhushan | |
26 | a14c36f9 | Shikhar Bhushan | class Session(Thread): |
27 | 216bb34c | Shikhar Bhushan | |
28 | 4f650d54 | Shikhar Bhushan | "Base class for use by transport protocol implementations."
|
29 | 4f650d54 | Shikhar Bhushan | |
30 | 2f8bc438 | Shikhar Bhushan | def __init__(self, capabilities): |
31 | a14c36f9 | Shikhar Bhushan | Thread.__init__(self)
|
32 | 4f650d54 | Shikhar Bhushan | self.setDaemon(True) |
33 | 4f650d54 | Shikhar Bhushan | self._listeners = set() # 3.0's weakset would be ideal |
34 | a14c36f9 | Shikhar Bhushan | self._lock = Lock()
|
35 | 4f650d54 | Shikhar Bhushan | self.setName('session') |
36 | d6688264 | Shikhar Bhushan | self._q = Queue()
|
37 | 2f8bc438 | Shikhar Bhushan | self._client_capabilities = capabilities
|
38 | d095a59e | Shikhar Bhushan | self._server_capabilities = None # yet |
39 | d095a59e | Shikhar Bhushan | self._id = None # session-id |
40 | d095a59e | Shikhar Bhushan | self._connected = False # to be set/cleared by subclass implementation |
41 | 41e2ed46 | Shikhar Bhushan | logger.debug('%r created: client_capabilities=%r' %
|
42 | 41e2ed46 | Shikhar Bhushan | (self, self._client_capabilities)) |
43 | 4f650d54 | Shikhar Bhushan | |
44 | a14c36f9 | Shikhar Bhushan | def _dispatch_message(self, raw): |
45 | a14c36f9 | Shikhar Bhushan | try:
|
46 | 57b5f922 | Shikhar Bhushan | root = xml_.parse_root(raw) |
47 | a14c36f9 | Shikhar Bhushan | except Exception as e: |
48 | a14c36f9 | Shikhar Bhushan | logger.error('error parsing dispatch message: %s' % e)
|
49 | a14c36f9 | Shikhar Bhushan | return
|
50 | a14c36f9 | Shikhar Bhushan | with self._lock: |
51 | a14c36f9 | Shikhar Bhushan | listeners = list(self._listeners) |
52 | a14c36f9 | Shikhar Bhushan | for l in listeners: |
53 | a14c36f9 | Shikhar Bhushan | logger.debug('dispatching message to %r' % l)
|
54 | a14c36f9 | Shikhar Bhushan | try:
|
55 | a14c36f9 | Shikhar Bhushan | l.callback(root, raw) |
56 | a14c36f9 | Shikhar Bhushan | except Exception as e: |
57 | a14c36f9 | Shikhar Bhushan | logger.warning('[error] %r' % e)
|
58 | 4f650d54 | Shikhar Bhushan | |
59 | a14c36f9 | Shikhar Bhushan | def _dispatch_error(self, err): |
60 | a14c36f9 | Shikhar Bhushan | with self._lock: |
61 | a14c36f9 | Shikhar Bhushan | listeners = list(self._listeners) |
62 | a14c36f9 | Shikhar Bhushan | for l in listeners: |
63 | a14c36f9 | Shikhar Bhushan | logger.debug('dispatching error to %r' % l)
|
64 | a14c36f9 | Shikhar Bhushan | try:
|
65 | a14c36f9 | Shikhar Bhushan | l.errback(err) |
66 | a14c36f9 | Shikhar Bhushan | except Exception as e: |
67 | 0b7d3b31 | Shikhar Bhushan | logger.warning('error dispatching to %r: %r' % (l, e))
|
68 | 4f650d54 | Shikhar Bhushan | |
69 | 65c6a607 | Shikhar Bhushan | def _post_connect(self): |
70 | 65c6a607 | Shikhar Bhushan | "Greeting stuff"
|
71 | 65c6a607 | Shikhar Bhushan | init_event = Event() |
72 | 65c6a607 | Shikhar Bhushan | error = [None] # so that err_cb can bind error[0]. just how it is. |
73 | 65c6a607 | Shikhar Bhushan | # callbacks
|
74 | 65c6a607 | Shikhar Bhushan | def ok_cb(id, capabilities): |
75 | 65c6a607 | Shikhar Bhushan | self._id = id |
76 | 583c11f6 | Shikhar Bhushan | self._server_capabilities = capabilities
|
77 | 65c6a607 | Shikhar Bhushan | init_event.set() |
78 | 65c6a607 | Shikhar Bhushan | def err_cb(err): |
79 | 65c6a607 | Shikhar Bhushan | error[0] = err
|
80 | 65c6a607 | Shikhar Bhushan | init_event.set() |
81 | 65c6a607 | Shikhar Bhushan | listener = HelloHandler(ok_cb, err_cb) |
82 | 65c6a607 | Shikhar Bhushan | self.add_listener(listener)
|
83 | 65c6a607 | Shikhar Bhushan | self.send(HelloHandler.build(self._client_capabilities)) |
84 | 65c6a607 | Shikhar Bhushan | logger.debug('starting main loop')
|
85 | 65c6a607 | Shikhar Bhushan | self.start()
|
86 | 65c6a607 | Shikhar Bhushan | # we expect server's hello message
|
87 | 65c6a607 | Shikhar Bhushan | init_event.wait() |
88 | 65c6a607 | Shikhar Bhushan | # received hello message or an error happened
|
89 | 65c6a607 | Shikhar Bhushan | self.remove_listener(listener)
|
90 | 65c6a607 | Shikhar Bhushan | if error[0]: |
91 | 65c6a607 | Shikhar Bhushan | raise error[0] |
92 | 216bb34c | Shikhar Bhushan | #if ':base:1.0' not in self.server_capabilities:
|
93 | 216bb34c | Shikhar Bhushan | # raise MissingCapabilityError(':base:1.0')
|
94 | 4f650d54 | Shikhar Bhushan | logger.info('initialized: session-id=%s | server_capabilities=%s' %
|
95 | 4f650d54 | Shikhar Bhushan | (self._id, self._server_capabilities)) |
96 | 4f650d54 | Shikhar Bhushan | |
97 | a14c36f9 | Shikhar Bhushan | def add_listener(self, listener): |
98 | 4f650d54 | Shikhar Bhushan | """Register a listener that will be notified of incoming messages and
|
99 | 4f650d54 | Shikhar Bhushan | errors.
|
100 | 4f650d54 | Shikhar Bhushan |
|
101 | 216bb34c | Shikhar Bhushan | :type listener: :class:`SessionListener`
|
102 | 0cdb8b3c | Shikhar Bhushan | """
|
103 | a14c36f9 | Shikhar Bhushan | logger.debug('installing listener %r' % listener)
|
104 | 583c11f6 | Shikhar Bhushan | if not isinstance(listener, SessionListener): |
105 | 583c11f6 | Shikhar Bhushan | raise SessionError("Listener must be a SessionListener type") |
106 | a14c36f9 | Shikhar Bhushan | with self._lock: |
107 | a14c36f9 | Shikhar Bhushan | self._listeners.add(listener)
|
108 | 4f650d54 | Shikhar Bhushan | |
109 | a14c36f9 | Shikhar Bhushan | def remove_listener(self, listener): |
110 | 4f650d54 | Shikhar Bhushan | """Unregister some listener; ignore if the listener was never
|
111 | 216bb34c | Shikhar Bhushan | registered.
|
112 | 216bb34c | Shikhar Bhushan |
|
113 | 216bb34c | Shikhar Bhushan | :type listener: :class:`SessionListener`
|
114 | 216bb34c | Shikhar Bhushan | """
|
115 | a14c36f9 | Shikhar Bhushan | logger.debug('discarding listener %r' % listener)
|
116 | a14c36f9 | Shikhar Bhushan | with self._lock: |
117 | a14c36f9 | Shikhar Bhushan | self._listeners.discard(listener)
|
118 | 4f650d54 | Shikhar Bhushan | |
119 | a14c36f9 | Shikhar Bhushan | def get_listener_instance(self, cls): |
120 | 216bb34c | Shikhar Bhushan | """If a listener of the specified type is registered, returns the
|
121 | 216bb34c | Shikhar Bhushan | instance.
|
122 | 4f650d54 | Shikhar Bhushan |
|
123 | 216bb34c | Shikhar Bhushan | :type cls: :class:`SessionListener`
|
124 | 0cdb8b3c | Shikhar Bhushan | """
|
125 | a14c36f9 | Shikhar Bhushan | with self._lock: |
126 | a14c36f9 | Shikhar Bhushan | for listener in self._listeners: |
127 | a14c36f9 | Shikhar Bhushan | if isinstance(listener, cls): |
128 | a14c36f9 | Shikhar Bhushan | return listener
|
129 | 4f650d54 | Shikhar Bhushan | |
130 | 0cdb8b3c | Shikhar Bhushan | def connect(self, *args, **kwds): # subclass implements |
131 | d095a59e | Shikhar Bhushan | raise NotImplementedError |
132 | d095a59e | Shikhar Bhushan | |
133 | 0cdb8b3c | Shikhar Bhushan | def run(self): # subclass implements |
134 | d095a59e | Shikhar Bhushan | raise NotImplementedError |
135 | 4f650d54 | Shikhar Bhushan | |
136 | d6688264 | Shikhar Bhushan | def send(self, message): |
137 | 4f650d54 | Shikhar Bhushan | """Send the supplied *message* to NETCONF server.
|
138 | 4f650d54 | Shikhar Bhushan |
|
139 | 4f650d54 | Shikhar Bhushan | :arg message: an XML document
|
140 | 4f650d54 | Shikhar Bhushan |
|
141 | 216bb34c | Shikhar Bhushan | :type message: `string`
|
142 | 0cdb8b3c | Shikhar Bhushan | """
|
143 | 66cd54c8 | Shikhar Bhushan | if not self.connected: |
144 | 66cd54c8 | Shikhar Bhushan | raise TransportError('Not connected to NETCONF server') |
145 | d6688264 | Shikhar Bhushan | logger.debug('queueing %s' % message)
|
146 | d6688264 | Shikhar Bhushan | self._q.put(message)
|
147 | 4f650d54 | Shikhar Bhushan | |
148 | d095a59e | Shikhar Bhushan | ### Properties
|
149 | 0cdb8b3c | Shikhar Bhushan | |
150 | 0cdb8b3c | Shikhar Bhushan | @property
|
151 | 0cdb8b3c | Shikhar Bhushan | def connected(self): |
152 | 4f650d54 | Shikhar Bhushan | "Connection status of the session."
|
153 | 0cdb8b3c | Shikhar Bhushan | return self._connected |
154 | 0cdb8b3c | Shikhar Bhushan | |
155 | d095a59e | Shikhar Bhushan | @property
|
156 | d095a59e | Shikhar Bhushan | def client_capabilities(self): |
157 | 4f650d54 | Shikhar Bhushan | "Client's :class:`Capabilities`"
|
158 | d095a59e | Shikhar Bhushan | return self._client_capabilities |
159 | 4f650d54 | Shikhar Bhushan | |
160 | d095a59e | Shikhar Bhushan | @property
|
161 | d095a59e | Shikhar Bhushan | def server_capabilities(self): |
162 | 4f650d54 | Shikhar Bhushan | "Server's :class:`Capabilities`"
|
163 | d095a59e | Shikhar Bhushan | return self._server_capabilities |
164 | 4f650d54 | Shikhar Bhushan | |
165 | d095a59e | Shikhar Bhushan | @property
|
166 | d095a59e | Shikhar Bhushan | def id(self): |
167 | 216bb34c | Shikhar Bhushan | """A `string` representing the `session-id`. If the session has not
|
168 | 4f650d54 | Shikhar Bhushan | been initialized it will be :const:`None`"""
|
169 | d095a59e | Shikhar Bhushan | return self._id |
170 | 4f650d54 | Shikhar Bhushan | |
171 | 94803aaf | Shikhar Bhushan | @property
|
172 | 94803aaf | Shikhar Bhushan | def can_pipeline(self): |
173 | 4f650d54 | Shikhar Bhushan | "Whether this session supports pipelining"
|
174 | 94803aaf | Shikhar Bhushan | return True |
175 | 583c11f6 | Shikhar Bhushan | |
176 | 583c11f6 | Shikhar Bhushan | |
177 | 583c11f6 | Shikhar Bhushan | class SessionListener(object): |
178 | 4f650d54 | Shikhar Bhushan | |
179 | 4f650d54 | Shikhar Bhushan | """Base class for :class:`Session` listeners, which are notified when a new
|
180 | 4f650d54 | Shikhar Bhushan | NETCONF message is received or an error occurs.
|
181 | 4f650d54 | Shikhar Bhushan |
|
182 | 0cdb8b3c | Shikhar Bhushan | .. note::
|
183 | 4f650d54 | Shikhar Bhushan | Avoid time-intensive tasks in a callback's context.
|
184 | 0cdb8b3c | Shikhar Bhushan | """
|
185 | 4f650d54 | Shikhar Bhushan | |
186 | 583c11f6 | Shikhar Bhushan | def callback(self, root, raw): |
187 | 4f650d54 | Shikhar Bhushan | """Called when a new XML document is received. The `root` argument
|
188 | 4f650d54 | Shikhar Bhushan | allows the callback to determine whether it wants to further process the
|
189 | 4f650d54 | Shikhar Bhushan | document.
|
190 | 4f650d54 | Shikhar Bhushan |
|
191 | 66cd54c8 | Shikhar Bhushan | :arg root: tuple of `(tag, attributes)` where `tag` is the qualified name of the root element and `attributes` is a dictionary of its attributes (also qualified names)
|
192 | 216bb34c | Shikhar Bhushan | :type root: `tuple`
|
193 | 4f650d54 | Shikhar Bhushan |
|
194 | 4f650d54 | Shikhar Bhushan | :arg raw: XML document
|
195 | 216bb34c | Shikhar Bhushan | :type raw: `string`
|
196 | 0cdb8b3c | Shikhar Bhushan | """
|
197 | 583c11f6 | Shikhar Bhushan | raise NotImplementedError |
198 | 4f650d54 | Shikhar Bhushan | |
199 | 583c11f6 | Shikhar Bhushan | def errback(self, ex): |
200 | 0cdb8b3c | Shikhar Bhushan | """Called when an error occurs.
|
201 | 4f650d54 | Shikhar Bhushan |
|
202 | 4f650d54 | Shikhar Bhushan | :type ex: :exc:`Exception`
|
203 | 0cdb8b3c | Shikhar Bhushan | """
|
204 | 583c11f6 | Shikhar Bhushan | raise NotImplementedError |
205 | 583c11f6 | Shikhar Bhushan | |
206 | 583c11f6 | Shikhar Bhushan | |
207 | 583c11f6 | Shikhar Bhushan | class HelloHandler(SessionListener): |
208 | 4f650d54 | Shikhar Bhushan | |
209 | 583c11f6 | Shikhar Bhushan | def __init__(self, init_cb, error_cb): |
210 | 583c11f6 | Shikhar Bhushan | self._init_cb = init_cb
|
211 | 583c11f6 | Shikhar Bhushan | self._error_cb = error_cb
|
212 | 4f650d54 | Shikhar Bhushan | |
213 | 583c11f6 | Shikhar Bhushan | def callback(self, root, raw): |
214 | 57b5f922 | Shikhar Bhushan | if xml_.unqualify(root[0]) == 'hello': |
215 | 583c11f6 | Shikhar Bhushan | try:
|
216 | 583c11f6 | Shikhar Bhushan | id, capabilities = HelloHandler.parse(raw)
|
217 | 583c11f6 | Shikhar Bhushan | except Exception as e: |
218 | 583c11f6 | Shikhar Bhushan | self._error_cb(e)
|
219 | 583c11f6 | Shikhar Bhushan | else:
|
220 | 583c11f6 | Shikhar Bhushan | self._init_cb(id, capabilities) |
221 | 4f650d54 | Shikhar Bhushan | |
222 | 583c11f6 | Shikhar Bhushan | def errback(self, err): |
223 | 583c11f6 | Shikhar Bhushan | self._error_cb(err)
|
224 | 4f650d54 | Shikhar Bhushan | |
225 | 583c11f6 | Shikhar Bhushan | @staticmethod
|
226 | 583c11f6 | Shikhar Bhushan | def build(capabilities): |
227 | 583c11f6 | Shikhar Bhushan | "Given a list of capability URI's returns <hello> message XML string"
|
228 | 583c11f6 | Shikhar Bhushan | spec = { |
229 | 8edc9de0 | Shikhar Bhushan | 'tag': 'hello', |
230 | 57b5f922 | Shikhar Bhushan | 'attrib': {'xmlns': xml_.BASE_NS}, |
231 | 583c11f6 | Shikhar Bhushan | 'subtree': [{
|
232 | 583c11f6 | Shikhar Bhushan | 'tag': 'capabilities', |
233 | 583c11f6 | Shikhar Bhushan | 'subtree': # this is fun :-) |
234 | 583c11f6 | Shikhar Bhushan | [{'tag': 'capability', 'text': uri} for uri in capabilities] |
235 | 583c11f6 | Shikhar Bhushan | }] |
236 | 583c11f6 | Shikhar Bhushan | } |
237 | 57b5f922 | Shikhar Bhushan | return xml_.dtree2xml(spec)
|
238 | 4f650d54 | Shikhar Bhushan | |
239 | 583c11f6 | Shikhar Bhushan | @staticmethod
|
240 | 583c11f6 | Shikhar Bhushan | def parse(raw): |
241 | 583c11f6 | Shikhar Bhushan | "Returns tuple of (session-id (str), capabilities (Capabilities)"
|
242 | 583c11f6 | Shikhar Bhushan | sid, capabilities = 0, []
|
243 | 57b5f922 | Shikhar Bhushan | root = xml_.xml2ele(raw) |
244 | 583c11f6 | Shikhar Bhushan | for child in root.getchildren(): |
245 | 57b5f922 | Shikhar Bhushan | tag = xml_.unqualify(child.tag) |
246 | 583c11f6 | Shikhar Bhushan | if tag == 'session-id': |
247 | 583c11f6 | Shikhar Bhushan | sid = child.text |
248 | 583c11f6 | Shikhar Bhushan | elif tag == 'capabilities': |
249 | 583c11f6 | Shikhar Bhushan | for cap in child.getchildren(): |
250 | 57b5f922 | Shikhar Bhushan | if xml_.unqualify(cap.tag) == 'capability': |
251 | 583c11f6 | Shikhar Bhushan | capabilities.append(cap.text) |
252 | 583c11f6 | Shikhar Bhushan | return sid, Capabilities(capabilities) |