| #!/usr/bin/env python |
| # |
| # Copyright (c) 2016 Cisco and/or its affiliates. |
| # 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. |
| # |
| |
| from __future__ import print_function |
| from __future__ import absolute_import |
| import sys |
| import os |
| import logging |
| import collections |
| import struct |
| import json |
| import threading |
| import fnmatch |
| import weakref |
| import atexit |
| from . vpp_serializer import VPPType, VPPEnumType, VPPUnionType, BaseTypes |
| from . vpp_serializer import VPPMessage, vpp_get_type |
| from . vpp_format import VPPFormat |
| |
| if sys.version[0] == '2': |
| import Queue as queue |
| else: |
| import queue as queue |
| |
| |
| class VppEnumType(type): |
| def __getattr__(cls, name): |
| t = vpp_get_type(name) |
| return t.enum |
| |
| |
| # Python3 |
| # class VppEnum(metaclass=VppEnumType): |
| # pass |
| class VppEnum: |
| __metaclass__ = VppEnumType |
| |
| |
| def vpp_atexit(vpp_weakref): |
| """Clean up VPP connection on shutdown.""" |
| vpp_instance = vpp_weakref() |
| if vpp_instance and vpp_instance.transport.connected: |
| vpp_instance.logger.debug('Cleaning up VPP on exit') |
| vpp_instance.disconnect() |
| |
| |
| def vpp_iterator(d): |
| if sys.version[0] == '2': |
| return d.iteritems() |
| else: |
| return d.items() |
| |
| |
| class VppApiDynamicMethodHolder(object): |
| pass |
| |
| |
| class FuncWrapper(object): |
| def __init__(self, func): |
| self._func = func |
| self.__name__ = func.__name__ |
| |
| def __call__(self, **kwargs): |
| return self._func(**kwargs) |
| |
| |
| class VPP(): |
| """VPP interface. |
| |
| This class provides the APIs to VPP. The APIs are loaded |
| from provided .api.json files and makes functions accordingly. |
| These functions are documented in the VPP .api files, as they |
| are dynamically created. |
| |
| Additionally, VPP can send callback messages; this class |
| provides a means to register a callback function to receive |
| these messages in a background thread. |
| """ |
| |
| def process_json_file(self, apidef_file): |
| api = json.load(apidef_file) |
| types = {} |
| for t in api['enums']: |
| t[0] = 'vl_api_' + t[0] + '_t' |
| types[t[0]] = {'type': 'enum', 'data': t} |
| for t in api['unions']: |
| t[0] = 'vl_api_' + t[0] + '_t' |
| types[t[0]] = {'type': 'union', 'data': t} |
| for t in api['types']: |
| t[0] = 'vl_api_' + t[0] + '_t' |
| types[t[0]] = {'type': 'type', 'data': t} |
| |
| i = 0 |
| while True: |
| unresolved = {} |
| for k, v in types.items(): |
| t = v['data'] |
| if not vpp_get_type(t[0]): |
| if v['type'] == 'enum': |
| try: |
| VPPEnumType(t[0], t[1:]) |
| except ValueError: |
| unresolved[k] = v |
| elif v['type'] == 'union': |
| try: |
| VPPUnionType(t[0], t[1:]) |
| except ValueError: |
| unresolved[k] = v |
| elif v['type'] == 'type': |
| try: |
| VPPType(t[0], t[1:]) |
| except ValueError: |
| unresolved[k] = v |
| if len(unresolved) == 0: |
| break |
| if i > 3: |
| raise ValueError('Unresolved type definitions {}' |
| .format(unresolved)) |
| types = unresolved |
| i += 1 |
| |
| for m in api['messages']: |
| try: |
| self.messages[m[0]] = VPPMessage(m[0], m[1:]) |
| except NotImplementedError: |
| self.logger.error('Not implemented error for {}'.format(m[0])) |
| |
| def __init__(self, apifiles=None, testmode=False, async_thread=True, |
| logger=logging.getLogger('vpp_papi'), loglevel='debug', |
| read_timeout=5, use_socket=False, |
| server_address='/run/vpp-api.sock'): |
| """Create a VPP API object. |
| |
| apifiles is a list of files containing API |
| descriptions that will be loaded - methods will be |
| dynamically created reflecting these APIs. If not |
| provided this will load the API files from VPP's |
| default install location. |
| |
| logger, if supplied, is the logging logger object to log to. |
| loglevel, if supplied, is the log level this logger is set |
| to report at (from the loglevels in the logging module). |
| """ |
| if logger is None: |
| logger = logging.getLogger(__name__) |
| if loglevel is not None: |
| logger.setLevel(loglevel) |
| self.logger = logger |
| |
| self.messages = {} |
| self.id_names = [] |
| self.id_msgdef = [] |
| self.header = VPPType('header', [['u16', 'msgid'], |
| ['u32', 'client_index']]) |
| self.apifiles = [] |
| self.event_callback = None |
| self.message_queue = queue.Queue() |
| self.read_timeout = read_timeout |
| self.async_thread = async_thread |
| |
| if use_socket: |
| from . vpp_transport_socket import VppTransport |
| else: |
| from . vpp_transport_shmem import VppTransport |
| |
| if not apifiles: |
| # Pick up API definitions from default directory |
| try: |
| apifiles = self.find_api_files() |
| except RuntimeError: |
| # In test mode we don't care that we can't find the API files |
| if testmode: |
| apifiles = [] |
| else: |
| raise |
| |
| for file in apifiles: |
| with open(file) as apidef_file: |
| self.process_json_file(apidef_file) |
| |
| self.apifiles = apifiles |
| |
| # Basic sanity check |
| if len(self.messages) == 0 and not testmode: |
| raise ValueError(1, 'Missing JSON message definitions') |
| |
| self.transport = VppTransport(self, read_timeout=read_timeout, |
| server_address=server_address) |
| # Make sure we allow VPP to clean up the message rings. |
| atexit.register(vpp_atexit, weakref.ref(self)) |
| |
| class ContextId(object): |
| """Thread-safe provider of unique context IDs.""" |
| def __init__(self): |
| self.context = 0 |
| self.lock = threading.Lock() |
| |
| def __call__(self): |
| """Get a new unique (or, at least, not recently used) context.""" |
| with self.lock: |
| self.context += 1 |
| return self.context |
| get_context = ContextId() |
| |
| def get_type(self, name): |
| return vpp_get_type(name) |
| |
| @classmethod |
| def find_api_dir(cls): |
| """Attempt to find the best directory in which API definition |
| files may reside. If the value VPP_API_DIR exists in the environment |
| then it is first on the search list. If we're inside a recognized |
| location in a VPP source tree (src/scripts and src/vpp-api/python) |
| then entries from there to the likely locations in build-root are |
| added. Finally the location used by system packages is added. |
| |
| :returns: A single directory name, or None if no such directory |
| could be found. |
| """ |
| dirs = [] |
| |
| if 'VPP_API_DIR' in os.environ: |
| dirs.append(os.environ['VPP_API_DIR']) |
| |
| # perhaps we're in the 'src/scripts' or 'src/vpp-api/python' dir; |
| # in which case, plot a course to likely places in the src tree |
| import __main__ as main |
| if hasattr(main, '__file__'): |
| # get the path of the calling script |
| localdir = os.path.dirname(os.path.realpath(main.__file__)) |
| else: |
| # use cwd if there is no calling script |
| localdir = os.getcwd() |
| localdir_s = localdir.split(os.path.sep) |
| |
| def dmatch(dir): |
| """Match dir against right-hand components of the script dir""" |
| d = dir.split('/') # param 'dir' assumes a / separator |
| length = len(d) |
| return len(localdir_s) > length and localdir_s[-length:] == d |
| |
| def sdir(srcdir, variant): |
| """Build a path from srcdir to the staged API files of |
| 'variant' (typically '' or '_debug')""" |
| # Since 'core' and 'plugin' files are staged |
| # in separate directories, we target the parent dir. |
| return os.path.sep.join(( |
| srcdir, |
| 'build-root', |
| 'install-vpp%s-native' % variant, |
| 'vpp', |
| 'share', |
| 'vpp', |
| 'api', |
| )) |
| |
| srcdir = None |
| if dmatch('src/scripts'): |
| srcdir = os.path.sep.join(localdir_s[:-2]) |
| elif dmatch('src/vpp-api/python'): |
| srcdir = os.path.sep.join(localdir_s[:-3]) |
| elif dmatch('test'): |
| # we're apparently running tests |
| srcdir = os.path.sep.join(localdir_s[:-1]) |
| |
| if srcdir: |
| # we're in the source tree, try both the debug and release |
| # variants. |
| dirs.append(sdir(srcdir, '_debug')) |
| dirs.append(sdir(srcdir, '')) |
| |
| # Test for staged copies of the scripts |
| # For these, since we explicitly know if we're running a debug versus |
| # release variant, target only the relevant directory |
| if dmatch('build-root/install-vpp_debug-native/vpp/bin'): |
| srcdir = os.path.sep.join(localdir_s[:-4]) |
| dirs.append(sdir(srcdir, '_debug')) |
| if dmatch('build-root/install-vpp-native/vpp/bin'): |
| srcdir = os.path.sep.join(localdir_s[:-4]) |
| dirs.append(sdir(srcdir, '')) |
| |
| # finally, try the location system packages typically install into |
| dirs.append(os.path.sep.join(('', 'usr', 'share', 'vpp', 'api'))) |
| |
| # check the directories for existance; first one wins |
| for dir in dirs: |
| if os.path.isdir(dir): |
| return dir |
| |
| return None |
| |
| @classmethod |
| def find_api_files(cls, api_dir=None, patterns='*'): |
| """Find API definition files from the given directory tree with the |
| given pattern. If no directory is given then find_api_dir() is used |
| to locate one. If no pattern is given then all definition files found |
| in the directory tree are used. |
| |
| :param api_dir: A directory tree in which to locate API definition |
| files; subdirectories are descended into. |
| If this is None then find_api_dir() is called to discover it. |
| :param patterns: A list of patterns to use in each visited directory |
| when looking for files. |
| This can be a list/tuple object or a comma-separated string of |
| patterns. Each value in the list will have leading/trialing |
| whitespace stripped. |
| The pattern specifies the first part of the filename, '.api.json' |
| is appended. |
| The results are de-duplicated, thus overlapping patterns are fine. |
| If this is None it defaults to '*' meaning "all API files". |
| :returns: A list of file paths for the API files found. |
| """ |
| if api_dir is None: |
| api_dir = cls.find_api_dir() |
| if api_dir is None: |
| raise RuntimeError("api_dir cannot be located") |
| |
| if isinstance(patterns, list) or isinstance(patterns, tuple): |
| patterns = [p.strip() + '.api.json' for p in patterns] |
| else: |
| patterns = [p.strip() + '.api.json' for p in patterns.split(",")] |
| |
| api_files = [] |
| for root, dirnames, files in os.walk(api_dir): |
| # iterate all given patterns and de-dup the result |
| files = set(sum([fnmatch.filter(files, p) for p in patterns], [])) |
| for filename in files: |
| api_files.append(os.path.join(root, filename)) |
| |
| return api_files |
| |
| @property |
| def api(self): |
| if not hasattr(self, "_api"): |
| raise Exception("Not connected, api definitions not available") |
| return self._api |
| |
| def make_function(self, msg, i, multipart, do_async): |
| if (do_async): |
| def f(**kwargs): |
| return self._call_vpp_async(i, msg, **kwargs) |
| else: |
| def f(**kwargs): |
| return self._call_vpp(i, msg, multipart, **kwargs) |
| |
| f.__name__ = str(msg.name) |
| f.__doc__ = ", ".join(["%s %s" % |
| (msg.fieldtypes[j], k) |
| for j, k in enumerate(msg.fields)]) |
| return f |
| |
| def _register_functions(self, do_async=False): |
| self.id_names = [None] * (self.vpp_dictionary_maxid + 1) |
| self.id_msgdef = [None] * (self.vpp_dictionary_maxid + 1) |
| self._api = VppApiDynamicMethodHolder() |
| for name, msg in vpp_iterator(self.messages): |
| n = name + '_' + msg.crc[2:] |
| i = self.transport.get_msg_index(n.encode()) |
| if i > 0: |
| self.id_msgdef[i] = msg |
| self.id_names[i] = name |
| # TODO: Fix multipart (use services) |
| multipart = True if name.find('_dump') > 0 else False |
| f = self.make_function(msg, i, multipart, do_async) |
| setattr(self._api, name, FuncWrapper(f)) |
| else: |
| self.logger.debug( |
| 'No such message type or failed CRC checksum: %s', n) |
| |
| def connect_internal(self, name, msg_handler, chroot_prefix, rx_qlen, |
| do_async): |
| pfx = chroot_prefix.encode() if chroot_prefix else None |
| |
| rv = self.transport.connect(name.encode(), pfx, msg_handler, rx_qlen) |
| if rv != 0: |
| raise IOError(2, 'Connect failed') |
| self.vpp_dictionary_maxid = self.transport.msg_table_max_index() |
| self._register_functions(do_async=do_async) |
| |
| # Initialise control ping |
| crc = self.messages['control_ping'].crc |
| self.control_ping_index = self.transport.get_msg_index( |
| ('control_ping' + '_' + crc[2:]).encode()) |
| self.control_ping_msgdef = self.messages['control_ping'] |
| if self.async_thread: |
| self.event_thread = threading.Thread( |
| target=self.thread_msg_handler) |
| self.event_thread.daemon = True |
| self.event_thread.start() |
| return rv |
| |
| def connect(self, name, chroot_prefix=None, do_async=False, rx_qlen=32): |
| """Attach to VPP. |
| |
| name - the name of the client. |
| chroot_prefix - if VPP is chroot'ed, the prefix of the jail |
| do_async - if true, messages are sent without waiting for a reply |
| rx_qlen - the length of the VPP message receive queue between |
| client and server. |
| """ |
| msg_handler = self.transport.get_callback(do_async) |
| return self.connect_internal(name, msg_handler, chroot_prefix, rx_qlen, |
| do_async) |
| |
| def connect_sync(self, name, chroot_prefix=None, rx_qlen=32): |
| """Attach to VPP in synchronous mode. Application must poll for events. |
| |
| name - the name of the client. |
| chroot_prefix - if VPP is chroot'ed, the prefix of the jail |
| rx_qlen - the length of the VPP message receive queue between |
| client and server. |
| """ |
| |
| return self.connect_internal(name, None, chroot_prefix, rx_qlen, |
| do_async=False) |
| |
| def disconnect(self): |
| """Detach from VPP.""" |
| rv = self.transport.disconnect() |
| self.message_queue.put("terminate event thread") |
| return rv |
| |
| def msg_handler_sync(self, msg): |
| """Process an incoming message from VPP in sync mode. |
| |
| The message may be a reply or it may be an async notification. |
| """ |
| r = self.decode_incoming_msg(msg) |
| if r is None: |
| return |
| |
| # If we have a context, then use the context to find any |
| # request waiting for a reply |
| context = 0 |
| if hasattr(r, 'context') and r.context > 0: |
| context = r.context |
| |
| if context == 0: |
| # No context -> async notification that we feed to the callback |
| self.message_queue.put_nowait(r) |
| else: |
| raise IOError(2, 'RPC reply message received in event handler') |
| |
| def decode_incoming_msg(self, msg): |
| if not msg: |
| self.logger.warning('vpp_api.read failed') |
| return |
| (i, ci), size = self.header.unpack(msg, 0) |
| if self.id_names[i] == 'rx_thread_exit': |
| return |
| |
| # |
| # Decode message and returns a tuple. |
| # |
| msgobj = self.id_msgdef[i] |
| if not msgobj: |
| raise IOError(2, 'Reply message undefined') |
| |
| r, size = msgobj.unpack(msg) |
| return r |
| |
| def msg_handler_async(self, msg): |
| """Process a message from VPP in async mode. |
| |
| In async mode, all messages are returned to the callback. |
| """ |
| r = self.decode_incoming_msg(msg) |
| if r is None: |
| return |
| |
| msgname = type(r).__name__ |
| |
| if self.event_callback: |
| self.event_callback(msgname, r) |
| |
| def _control_ping(self, context): |
| """Send a ping command.""" |
| self._call_vpp_async(self.control_ping_index, |
| self.control_ping_msgdef, |
| context=context) |
| |
| def validate_args(self, msg, kwargs): |
| d = set(kwargs.keys()) - set(msg.field_by_name.keys()) |
| if d: |
| raise ValueError('Invalid argument {} to {}' |
| .format(list(d), msg.name)) |
| |
| def _call_vpp(self, i, msg, multipart, **kwargs): |
| """Given a message, send the message and await a reply. |
| |
| msgdef - the message packing definition |
| i - the message type index |
| multipart - True if the message returns multiple |
| messages in return. |
| context - context number - chosen at random if not |
| supplied. |
| The remainder of the kwargs are the arguments to the API call. |
| |
| The return value is the message or message array containing |
| the response. It will raise an IOError exception if there was |
| no response within the timeout window. |
| """ |
| |
| if 'context' not in kwargs: |
| context = self.get_context() |
| kwargs['context'] = context |
| else: |
| context = kwargs['context'] |
| kwargs['_vl_msg_id'] = i |
| |
| try: |
| if self.transport.socket_index: |
| kwargs['client_index'] = self.transport.socket_index |
| except AttributeError: |
| pass |
| self.validate_args(msg, kwargs) |
| b = msg.pack(kwargs) |
| self.transport.suspend() |
| |
| self.transport.write(b) |
| |
| if multipart: |
| # Send a ping after the request - we use its response |
| # to detect that we have seen all results. |
| self._control_ping(context) |
| |
| # Block until we get a reply. |
| rl = [] |
| while (True): |
| msg = self.transport.read() |
| if not msg: |
| raise IOError(2, 'VPP API client: read failed') |
| r = self.decode_incoming_msg(msg) |
| msgname = type(r).__name__ |
| if context not in r or r.context == 0 or context != r.context: |
| # Message being queued |
| self.message_queue.put_nowait(r) |
| continue |
| |
| if not multipart: |
| rl = r |
| break |
| if msgname == 'control_ping_reply': |
| break |
| |
| rl.append(r) |
| |
| self.transport.resume() |
| |
| return rl |
| |
| def _call_vpp_async(self, i, msg, **kwargs): |
| """Given a message, send the message and await a reply. |
| |
| msgdef - the message packing definition |
| i - the message type index |
| context - context number - chosen at random if not |
| supplied. |
| The remainder of the kwargs are the arguments to the API call. |
| """ |
| if 'context' not in kwargs: |
| context = self.get_context() |
| kwargs['context'] = context |
| else: |
| context = kwargs['context'] |
| try: |
| if self.transport.socket_index: |
| kwargs['client_index'] = self.transport.socket_index |
| except AttributeError: |
| kwargs['client_index'] = 0 |
| kwargs['_vl_msg_id'] = i |
| b = msg.pack(kwargs) |
| |
| self.transport.write(b) |
| |
| def register_event_callback(self, callback): |
| """Register a callback for async messages. |
| |
| This will be called for async notifications in sync mode, |
| and all messages in async mode. In sync mode, replies to |
| requests will not come here. |
| |
| callback is a fn(msg_type_name, msg_type) that will be |
| called when a message comes in. While this function is |
| executing, note that (a) you are in a background thread and |
| may wish to use threading.Lock to protect your datastructures, |
| and (b) message processing from VPP will stop (so if you take |
| a long while about it you may provoke reply timeouts or cause |
| VPP to fill the RX buffer). Passing None will disable the |
| callback. |
| """ |
| self.event_callback = callback |
| |
| def thread_msg_handler(self): |
| """Python thread calling the user registered message handler. |
| |
| This is to emulate the old style event callback scheme. Modern |
| clients should provide their own thread to poll the event |
| queue. |
| """ |
| while True: |
| r = self.message_queue.get() |
| if r == "terminate event thread": |
| break |
| msgname = type(r).__name__ |
| if self.event_callback: |
| self.event_callback(msgname, r) |
| |
| |
| # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4 |