+++ /dev/null
-#!/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
-import sys, os, logging, collections, struct, json, threading, glob
-import atexit
-
-logging.basicConfig(level=logging.DEBUG)
-import vpp_api
-
-def eprint(*args, **kwargs):
- """Print critical diagnostics to stderr."""
- print(*args, file=sys.stderr, **kwargs)
-
-def vpp_atexit(self):
- """Clean up VPP connection on shutdown."""
- if self.connected:
- eprint ('Cleaning up VPP on exit')
- self.disconnect()
-
-
-class Empty(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 __init__(self, apifiles = None, testmode = False):
- """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.
- """
- self.messages = {}
- self.id_names = []
- self.id_msgdef = []
- self.buffersize = 10000
- self.connected = False
- self.header = struct.Struct('>HI')
- self.results_lock = threading.Lock()
- self.results = {}
- self.timeout = 5
- self.apifiles = []
- self.event_callback = None
-
- if not apifiles:
- # Pick up API definitions from default directory
- apifiles = glob.glob('/usr/share/vpp/api/*.api.json')
-
- for file in apifiles:
- with open(file) as apidef_file:
- api = json.load(apidef_file)
- for t in api['types']:
- self.add_type(t[0], t[1:])
-
- for m in api['messages']:
- self.add_message(m[0], m[1:])
- self.apifiles = apifiles
-
- # Basic sanity check
- if len(self.messages) == 0 and not testmode:
- raise ValueError(1, 'Missing JSON message definitions')
-
- # Make sure we allow VPP to clean up the message rings.
- atexit.register(vpp_atexit, 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 status(self):
- """Debug function: report current VPP API status to stdout."""
- print('Connected') if self.connected else print('Not Connected')
- print('Read API definitions from', ', '.join(self.apifiles))
-
- def __struct (self, t, n = None, e = -1, vl = None):
- """Create a packing structure for a message."""
- base_types = { 'u8' : 'B',
- 'u16' : 'H',
- 'u32' : 'I',
- 'i32' : 'i',
- 'u64' : 'Q',
- 'f64' : 'd',
- }
- pack = None
- if t in base_types:
- pack = base_types[t]
- if not vl:
- if e > 0 and t == 'u8':
- # Fixed byte array
- return struct.Struct('>' + str(e) + 's')
- if e > 0:
- # Fixed array of base type
- return [e, struct.Struct('>' + base_types[t])]
- elif e == 0:
- # Old style variable array
- return [-1, struct.Struct('>' + base_types[t])]
- else:
- # Variable length array
- return [vl, struct.Struct('>s')] if t == 'u8' else \
- [vl, struct.Struct('>' + base_types[t])]
-
- return struct.Struct('>' + base_types[t])
-
- if t in self.messages:
- ### Return a list in case of array ###
- if e > 0 and not vl:
- return [e, lambda self, encode, buf, offset, args: (
- self.__struct_type(encode, self.messages[t], buf, offset,
- args))]
- if vl:
- return [vl, lambda self, encode, buf, offset, args: (
- self.__struct_type(encode, self.messages[t], buf, offset,
- args))]
- elif e == 0:
- # Old style VLA
- raise NotImplementedError(1, 'No support for compound types ' + t)
- return lambda self, encode, buf, offset, args: (
- self.__struct_type(encode, self.messages[t], buf, offset, args)
- )
-
- raise ValueError(1, 'Invalid message type: ' + t)
-
- def __struct_type(self, encode, msgdef, buf, offset, kwargs):
- """Get a message packer or unpacker."""
- if encode:
- return self.__struct_type_encode(msgdef, buf, offset, kwargs)
- else:
- return self.__struct_type_decode(msgdef, buf, offset)
-
- def __struct_type_encode(self, msgdef, buf, offset, kwargs):
- off = offset
- size = 0
-
- for k in kwargs:
- if k not in msgdef['args']:
- raise ValueError(1, 'Invalid field-name in message call ' + k)
-
- for k,v in msgdef['args'].iteritems():
- off += size
- if k in kwargs:
- if type(v) is list:
- if callable(v[1]):
- e = kwargs[v[0]] if v[0] in kwargs else v[0]
- size = 0
- for i in range(e):
- size += v[1](self, True, buf, off + size,
- kwargs[k][i])
- else:
- if v[0] in kwargs:
- l = kwargs[v[0]]
- else:
- l = len(kwargs[k])
- if v[1].size == 1:
- buf[off:off + l] = bytearray(kwargs[k])
- size = l
- else:
- size = 0
- for i in kwargs[k]:
- v[1].pack_into(buf, off + size, i)
- size += v[1].size
- else:
- if callable(v):
- size = v(self, True, buf, off, kwargs[k])
- else:
- v.pack_into(buf, off, kwargs[k])
- size = v.size
- else:
- size = v.size if not type(v) is list else 0
-
- return off + size - offset
-
-
- def __getitem__(self, name):
- if name in self.messages:
- return self.messages[name]
- return None
-
- def encode(self, msgdef, kwargs):
- # Make suitably large buffer
- buf = bytearray(self.buffersize)
- offset = 0
- size = self.__struct_type(True, msgdef, buf, offset, kwargs)
- return buf[:offset + size]
-
- def decode(self, msgdef, buf):
- return self.__struct_type(False, msgdef, buf, 0, None)[1]
-
- def __struct_type_decode(self, msgdef, buf, offset):
- res = []
- off = offset
- size = 0
- for k,v in msgdef['args'].iteritems():
- off += size
- if type(v) is list:
- lst = []
- if callable(v[1]): # compound type
- size = 0
- if v[0] in msgdef['args']: # vla
- e = res[v[2]]
- else: # fixed array
- e = v[0]
- res.append(lst)
- for i in range(e):
- (s,l) = v[1](self, False, buf, off + size, None)
- lst.append(l)
- size += s
- continue
- if v[1].size == 1:
- if type(v[0]) is int:
- size = len(buf) - off
- else:
- size = res[v[2]]
- res.append(buf[off:off + size])
- else:
- e = v[0] if type(v[0]) is int else res[v[2]]
- if e == -1:
- e = (len(buf) - off) / v[1].size
- lst = []
- res.append(lst)
- size = 0
- for i in range(e):
- lst.append(v[1].unpack_from(buf, off + size)[0])
- size += v[1].size
- else:
- if callable(v):
- (s,l) = v(self, False, buf, off, None)
- res.append(l)
- size += s
- else:
- res.append(v.unpack_from(buf, off)[0])
- size = v.size
-
- return off + size - offset, msgdef['return_tuple']._make(res)
-
- def ret_tup(self, name):
- if name in self.messages and 'return_tuple' in self.messages[name]:
- return self.messages[name]['return_tuple']
- return None
-
- def add_message(self, name, msgdef):
- if name in self.messages:
- raise ValueError('Duplicate message name: ' + name)
-
- args = collections.OrderedDict()
- argtypes = collections.OrderedDict()
- fields = []
- msg = {}
- for i, f in enumerate(msgdef):
- if type(f) is dict and 'crc' in f:
- msg['crc'] = f['crc']
- continue
- field_type = f[0]
- field_name = f[1]
- if len(f) == 3 and f[2] == 0 and i != len(msgdef) - 2:
- raise ValueError('Variable Length Array must be last: ' + name)
- args[field_name] = self.__struct(*f)
- argtypes[field_name] = field_type
- if len(f) == 4: # Find offset to # elements field
- args[field_name].append(args.keys().index(f[3]) - i)
- fields.append(field_name)
- msg['return_tuple'] = collections.namedtuple(name, fields,
- rename = True)
- self.messages[name] = msg
- self.messages[name]['args'] = args
- self.messages[name]['argtypes'] = argtypes
- return self.messages[name]
-
- def add_type(self, name, typedef):
- return self.add_message('vl_api_' + name + '_t', typedef)
-
- def make_function(self, name, i, msgdef, multipart, async):
- if (async):
- f = lambda **kwargs: (self._call_vpp_async(i, msgdef, **kwargs))
- else:
- f = lambda **kwargs: (self._call_vpp(i, msgdef, multipart, **kwargs))
- args = self.messages[name]['args']
- argtypes = self.messages[name]['argtypes']
- f.__name__ = str(name)
- f.__doc__ = ", ".join(["%s %s" % (argtypes[k], k) for k in args.keys()])
- return f
-
- @property
- def api(self):
- if not hasattr(self, "_api"):
- raise Exception("Not connected, api definitions not available")
- return self._api
-
- def _register_functions(self, async=False):
- self.id_names = [None] * (self.vpp_dictionary_maxid + 1)
- self.id_msgdef = [None] * (self.vpp_dictionary_maxid + 1)
- self._api = Empty()
- for name, msgdef in self.messages.iteritems():
- if name in self.vpp_dictionary:
- if self.messages[name]['crc'] != self.vpp_dictionary[name]['crc']:
- raise ValueError(3, 'Failed CRC checksum ' + name +
- ' ' + self.messages[name]['crc'] +
- ' ' + self.vpp_dictionary[name]['crc'])
- i = self.vpp_dictionary[name]['id']
- self.id_msgdef[i] = msgdef
- self.id_names[i] = name
- multipart = True if name.find('_dump') > 0 else False
- f = self.make_function(name, i, msgdef, multipart, async)
- setattr(self._api, name, FuncWrapper(f))
-
- # olf API stuff starts here - will be removed in 17.07
- if hasattr(self, name):
- raise NameError(
- 3, "Conflicting name in JSON definition: `%s'" % name)
- setattr(self, name, f)
- # old API stuff ends here
-
- def _write (self, buf):
- """Send a binary-packed message to VPP."""
- if not self.connected:
- raise IOError(1, 'Not connected')
- return vpp_api.write(str(buf))
-
- def _load_dictionary(self):
- self.vpp_dictionary = {}
- self.vpp_dictionary_maxid = 0
- d = vpp_api.msg_table()
-
- if not d:
- raise IOError(3, 'Cannot get VPP API dictionary')
- for i,n in d:
- name, crc = n.rsplit('_', 1)
- crc = '0x' + crc
- self.vpp_dictionary[name] = { 'id' : i, 'crc' : crc }
- self.vpp_dictionary_maxid = max(self.vpp_dictionary_maxid, i)
-
- def connect(self, name, chroot_prefix = None, 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
- 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.msg_handler_sync if not async else self.msg_handler_async
- if chroot_prefix is not None:
- rv = vpp_api.connect(name, msg_handler, rx_qlen, chroot_prefix)
- else:
- rv = vpp_api.connect(name, msg_handler, rx_qlen)
-
- if rv != 0:
- raise IOError(2, 'Connect failed')
- self.connected = True
-
- self._load_dictionary()
- self._register_functions(async=async)
-
- # Initialise control ping
- self.control_ping_index = self.vpp_dictionary['control_ping']['id']
- self.control_ping_msgdef = self.messages['control_ping']
-
- def disconnect(self):
- """Detach from VPP."""
- rv = vpp_api.disconnect()
- self.connected = False
- return rv
-
- def results_wait(self, context):
- """In a sync call, wait for the reply
-
- The context ID is used to pair reply to request.
- """
-
- # Results is filled by the background callback. It will
- # raise the event when the context receives a response.
- # Given there are two threads we have to be careful with the
- # use of results and the structures under it, hence the lock.
- with self.results_lock:
- result = self.results[context]
- ev = result['e']
-
- timed_out = not ev.wait(self.timeout)
-
- if timed_out:
- raise IOError(3, 'Waiting for reply timed out')
- else:
- with self.results_lock:
- result = self.results[context]
- del self.results[context]
- return result['r']
-
- def results_prepare(self, context, multi=False):
- """Prep for receiving a result in response to a request msg
-
- context - unique context number sent in request and
- returned in reply or replies
- multi - true if we expect multiple messages from this
- reply.
- """
-
- # The event is used to indicate that all results are in
- new_result = {
- 'e': threading.Event(),
- }
- if multi:
- # Make it clear to the BG thread it's going to see several
- # messages; messages are stored in a results array
- new_result['m'] = True
- new_result['r'] = []
-
- new_result['e'].clear()
-
- # Put the prepped result structure into results, at which point
- # the bg thread can also access it (hence the thread lock)
- with self.results_lock:
- self.results[context] = new_result
-
- 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
-
- msgname = type(r).__name__
-
- if context == 0:
- # No context -> async notification that we feed to the callback
- if self.event_callback:
- self.event_callback(msgname, r)
- else:
- # Context -> use the results structure (carefully) to find
- # who we're responding to and return the message to that
- # thread
- with self.results_lock:
- if context not in self.results:
- eprint('Not expecting results for this context', context, r)
- else:
- result = self.results[context]
-
- #
- # Collect results until control ping
- #
-
- if msgname == 'control_ping_reply':
- # End of a multipart
- result['e'].set()
- elif 'm' in self.results[context]:
- # One element in a multipart
- result['r'].append(r)
- else:
- # All of a single result
- result['r'] = r
- result['e'].set()
-
- def decode_incoming_msg(self, msg):
- if not msg:
- eprint('vpp_api.read failed')
- return
-
- i, ci = self.header.unpack_from(msg, 0)
- if self.id_names[i] == 'rx_thread_exit':
- return
-
- #
- # Decode message and returns a tuple.
- #
- msgdef = self.id_msgdef[i]
- if not msgdef:
- raise IOError(2, 'Reply message undefined')
-
- r = self.decode(msgdef, 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 _call_vpp(self, i, msgdef, 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.
- """
-
- # We need a context if not supplied, in order to get the
- # response
- context = kwargs.get('context', self.get_context())
- kwargs['context'] = context
-
- # Set up to receive a response
- self.results_prepare(context, multi=multipart)
-
- # Output the message
- self._call_vpp_async(i, msgdef, **kwargs)
-
- 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.
- r = self.results_wait(context)
-
- return r
-
- def _call_vpp_async(self, i, msgdef, **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 not 'context' in kwargs:
- context = self.get_context()
- kwargs['context'] = context
- else:
- context = kwargs['context']
- kwargs['_vl_msg_id'] = i
- b = self.encode(msgdef, kwargs)
-
- self._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
Code Review / vpp.git / blobdiff