3 # Copyright (c) 2016 Cisco and/or its affiliates.
4 # Licensed under the Apache License, Version 2.0 (the "License");
5 # you may not use this file except in compliance with the License.
6 # You may obtain a copy of the License at:
8 # http://www.apache.org/licenses/LICENSE-2.0
10 # Unless required by applicable law or agreed to in writing, software
11 # distributed under the License is distributed on an "AS IS" BASIS,
12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 # See the License for the specific language governing permissions and
14 # limitations under the License.
17 from __future__ import print_function
18 from __future__ import absolute_import
30 from . vpp_serializer import VPPType, VPPEnumType, VPPUnionType, BaseTypes
31 from . vpp_serializer import VPPMessage, vpp_get_type, VPPTypeAlias
32 from . macaddress import MACAddress, mac_pton, mac_ntop
34 logger = logging.getLogger(__name__)
36 if sys.version[0] == '2':
42 def metaclass(metaclass):
43 @functools.wraps(metaclass)
45 return metaclass(cls.__name__, cls.__bases__, cls.__dict__.copy())
50 class VppEnumType(type):
51 def __getattr__(cls, name):
52 t = vpp_get_type(name)
56 @metaclass(VppEnumType)
57 class VppEnum(object):
61 def vpp_atexit(vpp_weakref):
62 """Clean up VPP connection on shutdown."""
63 vpp_instance = vpp_weakref()
64 if vpp_instance and vpp_instance.transport.connected:
65 vpp_instance.logger.debug('Cleaning up VPP on exit')
66 vpp_instance.disconnect()
69 if sys.version[0] == '2':
77 def call_logger(msgdef, kwargs):
78 s = 'Calling {}('.format(msgdef.name)
79 for k, v in kwargs.items():
80 s += '{}:{} '.format(k, v)
86 s = 'Return from {}'.format(r)
90 class VppApiDynamicMethodHolder(object):
94 class FuncWrapper(object):
95 def __init__(self, func):
97 self.__name__ = func.__name__
99 def __call__(self, **kwargs):
100 return self._func(**kwargs)
103 class VPPApiError(Exception):
107 class VPPNotImplementedError(NotImplementedError):
111 class VPPIOError(IOError):
115 class VPPRuntimeError(RuntimeError):
119 class VPPValueError(ValueError):
126 This class provides the APIs to VPP. The APIs are loaded
127 from provided .api.json files and makes functions accordingly.
128 These functions are documented in the VPP .api files, as they
129 are dynamically created.
131 Additionally, VPP can send callback messages; this class
132 provides a means to register a callback function to receive
133 these messages in a background thread.
135 VPPApiError = VPPApiError
136 VPPRuntimeError = VPPRuntimeError
137 VPPValueError = VPPValueError
138 VPPNotImplementedError = VPPNotImplementedError
139 VPPIOError = VPPIOError
141 def process_json_file(self, apidef_file):
142 api = json.load(apidef_file)
144 for t in api['enums']:
145 t[0] = 'vl_api_' + t[0] + '_t'
146 types[t[0]] = {'type': 'enum', 'data': t}
147 for t in api['unions']:
148 t[0] = 'vl_api_' + t[0] + '_t'
149 types[t[0]] = {'type': 'union', 'data': t}
150 for t in api['types']:
151 t[0] = 'vl_api_' + t[0] + '_t'
152 types[t[0]] = {'type': 'type', 'data': t}
153 for t, v in api['aliases'].items():
154 types['vl_api_' + t + '_t'] = {'type': 'alias', 'data': v}
155 self.services.update(api['services'])
160 for k, v in types.items():
162 if not vpp_get_type(k):
163 if v['type'] == 'enum':
165 VPPEnumType(t[0], t[1:])
168 elif v['type'] == 'union':
170 VPPUnionType(t[0], t[1:])
173 elif v['type'] == 'type':
178 elif v['type'] == 'alias':
183 if len(unresolved) == 0:
186 raise VPPValueError('Unresolved type definitions {}'
191 for m in api['messages']:
193 self.messages[m[0]] = VPPMessage(m[0], m[1:])
194 except VPPNotImplementedError:
195 self.logger.error('Not implemented error for {}'.format(m[0]))
197 def __init__(self, apifiles=None, testmode=False, async_thread=True,
198 logger=None, loglevel=None,
199 read_timeout=5, use_socket=False,
200 server_address='/run/vpp-api.sock'):
201 """Create a VPP API object.
203 apifiles is a list of files containing API
204 descriptions that will be loaded - methods will be
205 dynamically created reflecting these APIs. If not
206 provided this will load the API files from VPP's
207 default install location.
209 logger, if supplied, is the logging logger object to log to.
210 loglevel, if supplied, is the log level this logger is set
211 to report at (from the loglevels in the logging module).
214 logger = logging.getLogger(__name__)
215 if loglevel is not None:
216 logger.setLevel(loglevel)
223 self.header = VPPType('header', [['u16', 'msgid'],
224 ['u32', 'client_index']])
226 self.event_callback = None
227 self.message_queue = queue.Queue()
228 self.read_timeout = read_timeout
229 self.async_thread = async_thread
232 from . vpp_transport_socket import VppTransport
234 from . vpp_transport_shmem import VppTransport
237 # Pick up API definitions from default directory
239 apifiles = self.find_api_files()
241 # In test mode we don't care that we can't find the API files
245 raise VPPRuntimeError
247 for file in apifiles:
248 with open(file) as apidef_file:
249 self.process_json_file(apidef_file)
251 self.apifiles = apifiles
254 if len(self.messages) == 0 and not testmode:
255 raise VPPValueError(1, 'Missing JSON message definitions')
257 self.transport = VppTransport(self, read_timeout=read_timeout,
258 server_address=server_address)
259 # Make sure we allow VPP to clean up the message rings.
260 atexit.register(vpp_atexit, weakref.ref(self))
262 class ContextId(object):
263 """Thread-safe provider of unique context IDs."""
266 self.lock = threading.Lock()
269 """Get a new unique (or, at least, not recently used) context."""
273 get_context = ContextId()
275 def get_type(self, name):
276 return vpp_get_type(name)
279 def find_api_dir(cls):
280 """Attempt to find the best directory in which API definition
281 files may reside. If the value VPP_API_DIR exists in the environment
282 then it is first on the search list. If we're inside a recognized
283 location in a VPP source tree (src/scripts and src/vpp-api/python)
284 then entries from there to the likely locations in build-root are
285 added. Finally the location used by system packages is added.
287 :returns: A single directory name, or None if no such directory
292 if 'VPP_API_DIR' in os.environ:
293 dirs.append(os.environ['VPP_API_DIR'])
295 # perhaps we're in the 'src/scripts' or 'src/vpp-api/python' dir;
296 # in which case, plot a course to likely places in the src tree
297 import __main__ as main
298 if hasattr(main, '__file__'):
299 # get the path of the calling script
300 localdir = os.path.dirname(os.path.realpath(main.__file__))
302 # use cwd if there is no calling script
303 localdir = os.getcwd()
304 localdir_s = localdir.split(os.path.sep)
307 """Match dir against right-hand components of the script dir"""
308 d = dir.split('/') # param 'dir' assumes a / separator
310 return len(localdir_s) > length and localdir_s[-length:] == d
312 def sdir(srcdir, variant):
313 """Build a path from srcdir to the staged API files of
314 'variant' (typically '' or '_debug')"""
315 # Since 'core' and 'plugin' files are staged
316 # in separate directories, we target the parent dir.
317 return os.path.sep.join((
320 'install-vpp%s-native' % variant,
328 if dmatch('src/scripts'):
329 srcdir = os.path.sep.join(localdir_s[:-2])
330 elif dmatch('src/vpp-api/python'):
331 srcdir = os.path.sep.join(localdir_s[:-3])
333 # we're apparently running tests
334 srcdir = os.path.sep.join(localdir_s[:-1])
337 # we're in the source tree, try both the debug and release
339 dirs.append(sdir(srcdir, '_debug'))
340 dirs.append(sdir(srcdir, ''))
342 # Test for staged copies of the scripts
343 # For these, since we explicitly know if we're running a debug versus
344 # release variant, target only the relevant directory
345 if dmatch('build-root/install-vpp_debug-native/vpp/bin'):
346 srcdir = os.path.sep.join(localdir_s[:-4])
347 dirs.append(sdir(srcdir, '_debug'))
348 if dmatch('build-root/install-vpp-native/vpp/bin'):
349 srcdir = os.path.sep.join(localdir_s[:-4])
350 dirs.append(sdir(srcdir, ''))
352 # finally, try the location system packages typically install into
353 dirs.append(os.path.sep.join(('', 'usr', 'share', 'vpp', 'api')))
355 # check the directories for existance; first one wins
357 if os.path.isdir(dir):
363 def find_api_files(cls, api_dir=None, patterns='*'):
364 """Find API definition files from the given directory tree with the
365 given pattern. If no directory is given then find_api_dir() is used
366 to locate one. If no pattern is given then all definition files found
367 in the directory tree are used.
369 :param api_dir: A directory tree in which to locate API definition
370 files; subdirectories are descended into.
371 If this is None then find_api_dir() is called to discover it.
372 :param patterns: A list of patterns to use in each visited directory
373 when looking for files.
374 This can be a list/tuple object or a comma-separated string of
375 patterns. Each value in the list will have leading/trialing
377 The pattern specifies the first part of the filename, '.api.json'
379 The results are de-duplicated, thus overlapping patterns are fine.
380 If this is None it defaults to '*' meaning "all API files".
381 :returns: A list of file paths for the API files found.
384 api_dir = cls.find_api_dir()
386 raise VPPApiError("api_dir cannot be located")
388 if isinstance(patterns, list) or isinstance(patterns, tuple):
389 patterns = [p.strip() + '.api.json' for p in patterns]
391 patterns = [p.strip() + '.api.json' for p in patterns.split(",")]
394 for root, dirnames, files in os.walk(api_dir):
395 # iterate all given patterns and de-dup the result
396 files = set(sum([fnmatch.filter(files, p) for p in patterns], []))
397 for filename in files:
398 api_files.append(os.path.join(root, filename))
404 if not hasattr(self, "_api"):
405 raise VPPApiError("Not connected, api definitions not available")
408 def make_function(self, msg, i, multipart, do_async):
411 return self._call_vpp_async(i, msg, **kwargs)
414 return self._call_vpp(i, msg, multipart, **kwargs)
416 f.__name__ = str(msg.name)
417 f.__doc__ = ", ".join(["%s %s" %
418 (msg.fieldtypes[j], k)
419 for j, k in enumerate(msg.fields)])
424 def _register_functions(self, do_async=False):
425 self.id_names = [None] * (self.vpp_dictionary_maxid + 1)
426 self.id_msgdef = [None] * (self.vpp_dictionary_maxid + 1)
427 self._api = VppApiDynamicMethodHolder()
428 for name, msg in vpp_iterator(self.messages):
429 n = name + '_' + msg.crc[2:]
430 i = self.transport.get_msg_index(n.encode('utf-8'))
432 self.id_msgdef[i] = msg
433 self.id_names[i] = name
435 # Create function for client side messages.
436 if name in self.services:
437 if 'stream' in self.services[name] and \
438 self.services[name]['stream']:
442 f = self.make_function(msg, i, multipart, do_async)
443 setattr(self._api, name, FuncWrapper(f))
446 'No such message type or failed CRC checksum: %s', n)
448 def connect_internal(self, name, msg_handler, chroot_prefix, rx_qlen,
450 pfx = chroot_prefix.encode('utf-8') if chroot_prefix else None
452 rv = self.transport.connect(name.encode('utf-8'), pfx,
453 msg_handler, rx_qlen)
455 raise VPPIOError(2, 'Connect failed')
456 self.vpp_dictionary_maxid = self.transport.msg_table_max_index()
457 self._register_functions(do_async=do_async)
459 # Initialise control ping
460 crc = self.messages['control_ping'].crc
461 self.control_ping_index = self.transport.get_msg_index(
462 ('control_ping' + '_' + crc[2:]).encode('utf-8'))
463 self.control_ping_msgdef = self.messages['control_ping']
464 if self.async_thread:
465 self.event_thread = threading.Thread(
466 target=self.thread_msg_handler)
467 self.event_thread.daemon = True
468 self.event_thread.start()
471 def connect(self, name, chroot_prefix=None, do_async=False, rx_qlen=32):
474 name - the name of the client.
475 chroot_prefix - if VPP is chroot'ed, the prefix of the jail
476 do_async - if true, messages are sent without waiting for a reply
477 rx_qlen - the length of the VPP message receive queue between
480 msg_handler = self.transport.get_callback(do_async)
481 return self.connect_internal(name, msg_handler, chroot_prefix, rx_qlen,
484 def connect_sync(self, name, chroot_prefix=None, rx_qlen=32):
485 """Attach to VPP in synchronous mode. Application must poll for events.
487 name - the name of the client.
488 chroot_prefix - if VPP is chroot'ed, the prefix of the jail
489 rx_qlen - the length of the VPP message receive queue between
493 return self.connect_internal(name, None, chroot_prefix, rx_qlen,
496 def disconnect(self):
497 """Detach from VPP."""
498 rv = self.transport.disconnect()
499 self.message_queue.put("terminate event thread")
502 def msg_handler_sync(self, msg):
503 """Process an incoming message from VPP in sync mode.
505 The message may be a reply or it may be an async notification.
507 r = self.decode_incoming_msg(msg)
511 # If we have a context, then use the context to find any
512 # request waiting for a reply
514 if hasattr(r, 'context') and r.context > 0:
518 # No context -> async notification that we feed to the callback
519 self.message_queue.put_nowait(r)
521 raise VPPIOError(2, 'RPC reply message received in event handler')
523 def has_context(self, msg):
527 header = VPPType('header_with_context', [['u16', 'msgid'],
528 ['u32', 'client_index'],
531 (i, ci, context), size = header.unpack(msg, 0)
532 if self.id_names[i] == 'rx_thread_exit':
536 # Decode message and returns a tuple.
538 msgobj = self.id_msgdef[i]
539 if 'context' in msgobj.field_by_name and context >= 0:
543 def decode_incoming_msg(self, msg, no_type_conversion=False):
545 self.logger.warning('vpp_api.read failed')
548 (i, ci), size = self.header.unpack(msg, 0)
549 if self.id_names[i] == 'rx_thread_exit':
553 # Decode message and returns a tuple.
555 msgobj = self.id_msgdef[i]
557 raise VPPIOError(2, 'Reply message undefined')
559 r, size = msgobj.unpack(msg, ntc=no_type_conversion)
562 def msg_handler_async(self, msg):
563 """Process a message from VPP in async mode.
565 In async mode, all messages are returned to the callback.
567 r = self.decode_incoming_msg(msg)
571 msgname = type(r).__name__
573 if self.event_callback:
574 self.event_callback(msgname, r)
576 def _control_ping(self, context):
577 """Send a ping command."""
578 self._call_vpp_async(self.control_ping_index,
579 self.control_ping_msgdef,
582 def validate_args(self, msg, kwargs):
583 d = set(kwargs.keys()) - set(msg.field_by_name.keys())
585 raise VPPValueError('Invalid argument {} to {}'
586 .format(list(d), msg.name))
588 def _call_vpp(self, i, msgdef, multipart, **kwargs):
589 """Given a message, send the message and await a reply.
591 msgdef - the message packing definition
592 i - the message type index
593 multipart - True if the message returns multiple
595 context - context number - chosen at random if not
597 The remainder of the kwargs are the arguments to the API call.
599 The return value is the message or message array containing
600 the response. It will raise an IOError exception if there was
601 no response within the timeout window.
604 if 'context' not in kwargs:
605 context = self.get_context()
606 kwargs['context'] = context
608 context = kwargs['context']
609 kwargs['_vl_msg_id'] = i
611 no_type_conversion = kwargs.pop('_no_type_conversion', False)
614 if self.transport.socket_index:
615 kwargs['client_index'] = self.transport.socket_index
616 except AttributeError:
618 self.validate_args(msgdef, kwargs)
620 logging.debug(call_logger(msgdef, kwargs))
622 b = msgdef.pack(kwargs)
623 self.transport.suspend()
625 self.transport.write(b)
628 # Send a ping after the request - we use its response
629 # to detect that we have seen all results.
630 self._control_ping(context)
632 # Block until we get a reply.
635 msg = self.transport.read()
637 raise VPPIOError(2, 'VPP API client: read failed')
638 r = self.decode_incoming_msg(msg, no_type_conversion)
639 msgname = type(r).__name__
640 if context not in r or r.context == 0 or context != r.context:
641 # Message being queued
642 self.message_queue.put_nowait(r)
648 if msgname == 'control_ping_reply':
653 self.transport.resume()
655 logger.debug(return_logger(rl))
658 def _call_vpp_async(self, i, msg, **kwargs):
659 """Given a message, send the message and await a reply.
661 msgdef - the message packing definition
662 i - the message type index
663 context - context number - chosen at random if not
665 The remainder of the kwargs are the arguments to the API call.
667 if 'context' not in kwargs:
668 context = self.get_context()
669 kwargs['context'] = context
671 context = kwargs['context']
673 if self.transport.socket_index:
674 kwargs['client_index'] = self.transport.socket_index
675 except AttributeError:
676 kwargs['client_index'] = 0
677 kwargs['_vl_msg_id'] = i
680 self.transport.write(b)
682 def register_event_callback(self, callback):
683 """Register a callback for async messages.
685 This will be called for async notifications in sync mode,
686 and all messages in async mode. In sync mode, replies to
687 requests will not come here.
689 callback is a fn(msg_type_name, msg_type) that will be
690 called when a message comes in. While this function is
691 executing, note that (a) you are in a background thread and
692 may wish to use threading.Lock to protect your datastructures,
693 and (b) message processing from VPP will stop (so if you take
694 a long while about it you may provoke reply timeouts or cause
695 VPP to fill the RX buffer). Passing None will disable the
698 self.event_callback = callback
700 def thread_msg_handler(self):
701 """Python thread calling the user registered message handler.
703 This is to emulate the old style event callback scheme. Modern
704 clients should provide their own thread to poll the event
708 r = self.message_queue.get()
709 if r == "terminate event thread":
711 msgname = type(r).__name__
712 if self.event_callback:
713 self.event_callback(msgname, r)
716 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4