#!/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 functools
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, VPPTypeAlias
from . macaddress import MACAddress, mac_pton, mac_ntop
logger = logging.getLogger(__name__)
if sys.version[0] == '2':
import Queue as queue
else:
import queue as queue
def metaclass(metaclass):
@functools.wraps(metaclass)
def wrapper(cls):
return metaclass(cls.__name__, cls.__bases__, cls.__dict__.copy())
return wrapper
class VppEnumType(type):
def __getattr__(cls, name):
t = vpp_get_type(name)
return t.enum
@metaclass(VppEnumType)
class VppEnum(object):
pass
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()
if sys.version[0] == '2':
def vpp_iterator(d):
return d.iteritems()
else:
def vpp_iterator(d):
return d.items()
def call_logger(msgdef, kwargs):
s = 'Calling {}('.format(msgdef.name)
for k, v in kwargs.items():
s += '{}:{} '.format(k, v)
s += ')'
return s
def return_logger(r):
s = 'Return from {}'.format(r)
return s
class VppApiDynamicMethodHolder(object):
pass
class FuncWrapper(object):
def __init__(self, func):
self._func = func
self.__name__ = func.__name__
self.__doc__ = func.__doc__
def __call__(self, **kwargs):
return self._func(**kwargs)
class VPPApiError(Exception):
pass
class VPPNotImplementedError(NotImplementedError):
pass
class VPPIOError(IOError):
pass
class VPPRuntimeError(RuntimeError):
pass
class VPPValueError(ValueError):
pass
class VPP(object):
"""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.
"""
VPPApiError = VPPApiError
VPPRuntimeError = VPPRuntimeError
VPPValueError = VPPValueError
VPPNotImplementedError = VPPNotImplementedError
VPPIOError = VPPIOError
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}
for t, v in api['aliases'].items():
types['vl_api_' + t + '_t'] = {'type': 'alias', 'data': v}
self.services.update(api['services'])
i = 0
while True:
unresolved = {}
for k, v in types.items():
t = v['data']
if not vpp_get_type(k):
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
elif v['type'] == 'alias':
try:
VPPTypeAlias(k, t)
except ValueError:
unresolved[k] = v
if len(unresolved) == 0:
break
if i > 3:
raise VPPValueError('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 VPPNotImplementedError:
self.logger.error('Not implemented error for {}'.format(m[0]))
def __init__(self, apifiles=None, testmode=False, async_thread=True,
logger=None, loglevel=None,
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.services = {}
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 VPPRuntimeError
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 VPPValueError(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 VPPApiError("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 VPPApiError("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)])
f.msg = msg
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('utf-8'))
if i > 0:
self.id_msgdef[i] = msg
self.id_names[i] = name
# Create function for client side messages.
if name in self.services:
if 'stream' in self.services[name] and \
self.services[name]['stream']:
multipart = True
else:
multipart = 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('utf-8') if chroot_prefix else None
rv = self.transport.connect(name.encode('utf-8'), pfx,
msg_handler, rx_qlen)
if rv != 0:
raise VPPIOError(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('utf-8'))
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 VPPIOError(2, 'RPC reply message received in event handler')
def has_context(self, msg):
if len(msg) < 10:
return False
header = VPPType('header_with_context', [['u16', 'msgid'],
['u32', 'client_index'],
['u32', 'context']])
(i, ci, context), size = 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 'context' in msgobj.field_by_name and context >= 0:
return True
return False
def decode_incoming_msg(self, msg, no_type_conversion=False):
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 VPPIOError(2, 'Reply message undefined')
r, size = msgobj.unpack(msg, ntc=no_type_conversion)
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 VPPValueError('Invalid argument {} to {}'
.format(list(d), msg.name))
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.
"""
if 'context' not in kwargs:
context = self.get_context()
kwargs['context'] = context
else:
context = kwargs['context']
kwargs['_vl_msg_id'] = i
no_type_conversion = kwargs.pop('_no_type_conversion', False)
try:
if self.transport.socket_index:
kwargs['client_index'] = self.transport.socket_index
except AttributeError:
pass
self.validate_args(msgdef, kwargs)
logging.debug(call_logger(msgdef, kwargs))
b = msgdef.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 VPPIOError(2, 'VPP API client: read failed')
r = self.decode_incoming_msg(msg, no_type_conversion)
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()
logger.debug(return_logger(rl))
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)
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