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__
98 self.__doc__ = func.__doc__
100 def __call__(self, **kwargs):
101 return self._func(**kwargs)
104 class VPPApiError(Exception):
108 class VPPNotImplementedError(NotImplementedError):
112 class VPPIOError(IOError):
116 class VPPRuntimeError(RuntimeError):
120 class VPPValueError(ValueError):
124 class VPPApiClient(object):
127 This class provides the APIs to VPP. The APIs are loaded
128 from provided .api.json files and makes functions accordingly.
129 These functions are documented in the VPP .api files, as they
130 are dynamically created.
132 Additionally, VPP can send callback messages; this class
133 provides a means to register a callback function to receive
134 these messages in a background thread.
137 VPPApiError = VPPApiError
138 VPPRuntimeError = VPPRuntimeError
139 VPPValueError = VPPValueError
140 VPPNotImplementedError = VPPNotImplementedError
141 VPPIOError = VPPIOError
143 def process_json_file(self, apidef_file):
144 api = json.load(apidef_file)
146 for t in api['enums']:
147 t[0] = 'vl_api_' + t[0] + '_t'
148 types[t[0]] = {'type': 'enum', 'data': t}
149 for t in api['unions']:
150 t[0] = 'vl_api_' + t[0] + '_t'
151 types[t[0]] = {'type': 'union', 'data': t}
152 for t in api['types']:
153 t[0] = 'vl_api_' + t[0] + '_t'
154 types[t[0]] = {'type': 'type', 'data': t}
155 for t, v in api['aliases'].items():
156 types['vl_api_' + t + '_t'] = {'type': 'alias', 'data': v}
157 self.services.update(api['services'])
162 for k, v in types.items():
164 if not vpp_get_type(k):
165 if v['type'] == 'enum':
167 VPPEnumType(t[0], t[1:])
170 elif v['type'] == 'union':
172 VPPUnionType(t[0], t[1:])
175 elif v['type'] == 'type':
180 elif v['type'] == 'alias':
185 if len(unresolved) == 0:
188 raise VPPValueError('Unresolved type definitions {}'
193 for m in api['messages']:
195 self.messages[m[0]] = VPPMessage(m[0], m[1:])
196 except VPPNotImplementedError:
197 self.logger.error('Not implemented error for {}'.format(m[0]))
199 def __init__(self, apifiles=None, testmode=False, async_thread=True,
200 logger=None, loglevel=None,
201 read_timeout=5, use_socket=False,
202 server_address='/run/vpp-api.sock'):
203 """Create a VPP API object.
205 apifiles is a list of files containing API
206 descriptions that will be loaded - methods will be
207 dynamically created reflecting these APIs. If not
208 provided this will load the API files from VPP's
209 default install location.
211 logger, if supplied, is the logging logger object to log to.
212 loglevel, if supplied, is the log level this logger is set
213 to report at (from the loglevels in the logging module).
216 logger = logging.getLogger(__name__)
217 if loglevel is not None:
218 logger.setLevel(loglevel)
225 self.header = VPPType('header', [['u16', 'msgid'],
226 ['u32', 'client_index']])
228 self.event_callback = None
229 self.message_queue = queue.Queue()
230 self.read_timeout = read_timeout
231 self.async_thread = async_thread
232 self.event_thread = None
235 from . vpp_transport_socket import VppTransport
237 from . vpp_transport_shmem import VppTransport
240 # Pick up API definitions from default directory
242 apifiles = self.find_api_files()
244 # In test mode we don't care that we can't find the API files
248 raise VPPRuntimeError
250 for file in apifiles:
251 with open(file) as apidef_file:
252 self.process_json_file(apidef_file)
254 self.apifiles = apifiles
257 if len(self.messages) == 0 and not testmode:
258 raise VPPValueError(1, 'Missing JSON message definitions')
260 self.transport = VppTransport(self, read_timeout=read_timeout,
261 server_address=server_address)
262 # Make sure we allow VPP to clean up the message rings.
263 atexit.register(vpp_atexit, weakref.ref(self))
265 class ContextId(object):
266 """Thread-safe provider of unique context IDs."""
269 self.lock = threading.Lock()
272 """Get a new unique (or, at least, not recently used) context."""
276 get_context = ContextId()
278 def get_type(self, name):
279 return vpp_get_type(name)
282 def find_api_dir(cls):
283 """Attempt to find the best directory in which API definition
284 files may reside. If the value VPP_API_DIR exists in the environment
285 then it is first on the search list. If we're inside a recognized
286 location in a VPP source tree (src/scripts and src/vpp-api/python)
287 then entries from there to the likely locations in build-root are
288 added. Finally the location used by system packages is added.
290 :returns: A single directory name, or None if no such directory
293 dirs = [cls.apidir] if cls.apidir else []
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 existence; 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()
470 self.event_thread = None
473 def connect(self, name, chroot_prefix=None, do_async=False, rx_qlen=32):
476 name - the name of the client.
477 chroot_prefix - if VPP is chroot'ed, the prefix of the jail
478 do_async - if true, messages are sent without waiting for a reply
479 rx_qlen - the length of the VPP message receive queue between
482 msg_handler = self.transport.get_callback(do_async)
483 return self.connect_internal(name, msg_handler, chroot_prefix, rx_qlen,
486 def connect_sync(self, name, chroot_prefix=None, rx_qlen=32):
487 """Attach to VPP in synchronous mode. Application must poll for events.
489 name - the name of the client.
490 chroot_prefix - if VPP is chroot'ed, the prefix of the jail
491 rx_qlen - the length of the VPP message receive queue between
495 return self.connect_internal(name, None, chroot_prefix, rx_qlen,
498 def disconnect(self):
499 """Detach from VPP."""
500 rv = self.transport.disconnect()
501 if self.event_thread is not None:
502 self.message_queue.put("terminate event thread")
505 def msg_handler_sync(self, msg):
506 """Process an incoming message from VPP in sync mode.
508 The message may be a reply or it may be an async notification.
510 r = self.decode_incoming_msg(msg)
514 # If we have a context, then use the context to find any
515 # request waiting for a reply
517 if hasattr(r, 'context') and r.context > 0:
521 # No context -> async notification that we feed to the callback
522 self.message_queue.put_nowait(r)
524 raise VPPIOError(2, 'RPC reply message received in event handler')
526 def has_context(self, msg):
530 header = VPPType('header_with_context', [['u16', 'msgid'],
531 ['u32', 'client_index'],
534 (i, ci, context), size = header.unpack(msg, 0)
535 if self.id_names[i] == 'rx_thread_exit':
539 # Decode message and returns a tuple.
541 msgobj = self.id_msgdef[i]
542 if 'context' in msgobj.field_by_name and context >= 0:
546 def decode_incoming_msg(self, msg, no_type_conversion=False):
548 self.logger.warning('vpp_api.read failed')
551 (i, ci), size = self.header.unpack(msg, 0)
552 if self.id_names[i] == 'rx_thread_exit':
556 # Decode message and returns a tuple.
558 msgobj = self.id_msgdef[i]
560 raise VPPIOError(2, 'Reply message undefined')
562 r, size = msgobj.unpack(msg, ntc=no_type_conversion)
565 def msg_handler_async(self, msg):
566 """Process a message from VPP in async mode.
568 In async mode, all messages are returned to the callback.
570 r = self.decode_incoming_msg(msg)
574 msgname = type(r).__name__
576 if self.event_callback:
577 self.event_callback(msgname, r)
579 def _control_ping(self, context):
580 """Send a ping command."""
581 self._call_vpp_async(self.control_ping_index,
582 self.control_ping_msgdef,
585 def validate_args(self, msg, kwargs):
586 d = set(kwargs.keys()) - set(msg.field_by_name.keys())
588 raise VPPValueError('Invalid argument {} to {}'
589 .format(list(d), msg.name))
591 def _call_vpp(self, i, msgdef, multipart, **kwargs):
592 """Given a message, send the message and await a reply.
594 msgdef - the message packing definition
595 i - the message type index
596 multipart - True if the message returns multiple
598 context - context number - chosen at random if not
600 The remainder of the kwargs are the arguments to the API call.
602 The return value is the message or message array containing
603 the response. It will raise an IOError exception if there was
604 no response within the timeout window.
607 if 'context' not in kwargs:
608 context = self.get_context()
609 kwargs['context'] = context
611 context = kwargs['context']
612 kwargs['_vl_msg_id'] = i
614 no_type_conversion = kwargs.pop('_no_type_conversion', False)
617 if self.transport.socket_index:
618 kwargs['client_index'] = self.transport.socket_index
619 except AttributeError:
621 self.validate_args(msgdef, kwargs)
623 logging.debug(call_logger(msgdef, kwargs))
625 b = msgdef.pack(kwargs)
626 self.transport.suspend()
628 self.transport.write(b)
631 # Send a ping after the request - we use its response
632 # to detect that we have seen all results.
633 self._control_ping(context)
635 # Block until we get a reply.
638 msg = self.transport.read()
640 raise VPPIOError(2, 'VPP API client: read failed')
641 r = self.decode_incoming_msg(msg, no_type_conversion)
642 msgname = type(r).__name__
643 if context not in r or r.context == 0 or context != r.context:
644 # Message being queued
645 self.message_queue.put_nowait(r)
651 if msgname == 'control_ping_reply':
656 self.transport.resume()
658 logger.debug(return_logger(rl))
661 def _call_vpp_async(self, i, msg, **kwargs):
662 """Given a message, send the message and await a reply.
664 msgdef - the message packing definition
665 i - the message type index
666 context - context number - chosen at random if not
668 The remainder of the kwargs are the arguments to the API call.
670 if 'context' not in kwargs:
671 context = self.get_context()
672 kwargs['context'] = context
674 context = kwargs['context']
676 if self.transport.socket_index:
677 kwargs['client_index'] = self.transport.socket_index
678 except AttributeError:
679 kwargs['client_index'] = 0
680 kwargs['_vl_msg_id'] = i
683 self.transport.write(b)
685 def register_event_callback(self, callback):
686 """Register a callback for async messages.
688 This will be called for async notifications in sync mode,
689 and all messages in async mode. In sync mode, replies to
690 requests will not come here.
692 callback is a fn(msg_type_name, msg_type) that will be
693 called when a message comes in. While this function is
694 executing, note that (a) you are in a background thread and
695 may wish to use threading.Lock to protect your datastructures,
696 and (b) message processing from VPP will stop (so if you take
697 a long while about it you may provoke reply timeouts or cause
698 VPP to fill the RX buffer). Passing None will disable the
701 self.event_callback = callback
703 def thread_msg_handler(self):
704 """Python thread calling the user registered message handler.
706 This is to emulate the old style event callback scheme. Modern
707 clients should provide their own thread to poll the event
711 r = self.message_queue.get()
712 if r == "terminate event thread":
714 msgname = type(r).__name__
715 if self.event_callback:
716 self.event_callback(msgname, r)
718 # Provide the old name for backward compatibility.
721 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4