import logging
import collections
import struct
+import functools
import json
import threading
import fnmatch
import weakref
import atexit
-from cffi import FFI
-import cffi
from . vpp_serializer import VPPType, VPPEnumType, VPPUnionType, BaseTypes
-from . vpp_serializer import VPPMessage
+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
-ffi = FFI()
-ffi.cdef("""
-typedef void (*vac_callback_t)(unsigned char * data, int len);
-typedef void (*vac_error_callback_t)(void *, unsigned char *, int);
-int vac_connect(char * name, char * chroot_prefix, vac_callback_t cb,
- int rx_qlen);
-int vac_disconnect(void);
-int vac_read(char **data, int *l, unsigned short timeout);
-int vac_write(char *data, int len);
-void vac_free(void * msg);
-int vac_get_msg_index(unsigned char * name);
-int vac_msg_table_size(void);
-int vac_msg_table_max_index(void);
+def metaclass(metaclass):
+ @functools.wraps(metaclass)
+ def wrapper(cls):
+ return metaclass(cls.__name__, cls.__bases__, cls.__dict__.copy())
+
+ return wrapper
-void vac_rx_suspend (void);
-void vac_rx_resume (void);
-void vac_set_error_handler(vac_error_callback_t);
- """)
-# Barfs on failure, no need to check success.
-vpp_api = ffi.dlopen('libvppapiclient.so')
+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.connected:
+ if vpp_instance and vpp_instance.transport.connected:
vpp_instance.logger.debug('Cleaning up VPP on exit')
vpp_instance.disconnect()
-vpp_object = None
-
-
-def vpp_iterator(d):
- if sys.version[0] == '2':
+if sys.version[0] == '2':
+ def vpp_iterator(d):
return d.iteritems()
- else:
+else:
+ def vpp_iterator(d):
return d.items()
-@ffi.callback("void(unsigned char *, int)")
-def vac_callback_sync(data, len):
- vpp_object.msg_handler_sync(ffi.buffer(data, len))
-
-
-@ffi.callback("void(unsigned char *, int)")
-def vac_callback_async(data, len):
- vpp_object.msg_handler_async(ffi.buffer(data, len))
+def call_logger(msgdef, kwargs):
+ s = 'Calling {}('.format(msgdef.name)
+ for k, v in kwargs.items():
+ s += '{}:{} '.format(k, v)
+ s += ')'
+ return s
-@ffi.callback("void(void *, unsigned char *, int)")
-def vac_error_handler(arg, msg, msg_len):
- vpp_object.logger.warning("VPP API client:: %s", ffi.string(msg, msg_len))
+def return_logger(r):
+ s = 'Return from {}'.format(r)
+ return s
class VppApiDynamicMethodHolder(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 VPP():
+class VPPApiError(Exception):
+ pass
+
+
+class VPPNotImplementedError(NotImplementedError):
+ pass
+
+
+class VPPIOError(IOError):
+ pass
+
+
+class VPPRuntimeError(RuntimeError):
+ pass
+
+
+class VPPValueError(ValueError):
+ pass
+
+
+class VPPApiClient(object):
"""VPP interface.
This class provides the APIs to VPP. The APIs are loaded
provides a means to register a callback function to receive
these messages in a background thread.
"""
+ apidir = None
+ VPPApiError = VPPApiError
+ VPPRuntimeError = VPPRuntimeError
+ VPPValueError = VPPValueError
+ VPPNotImplementedError = VPPNotImplementedError
+ VPPIOError = VPPIOError
def process_json_file(self, apidef_file):
api = json.load(apidef_file)
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 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 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 ValueError('Unresolved type definitions {}'
- .format(unresolved))
+ 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 NotImplementedError:
+ except VPPNotImplementedError:
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=0):
+ 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
loglevel, if supplied, is the log level this logger is set
to report at (from the loglevels in the logging module).
"""
- global vpp_object
- vpp_object = self
-
if logger is None:
logger = logging.getLogger(__name__)
if loglevel is not None:
self.logger = logger
self.messages = {}
+ self.services = {}
self.id_names = []
self.id_msgdef = []
- self.connected = False
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.vpp_api = vpp_api
self.async_thread = async_thread
+ self.event_thread = None
+
+ 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
if testmode:
apifiles = []
else:
- raise
+ raise VPPRuntimeError
for file in apifiles:
with open(file) as apidef_file:
# Basic sanity check
if len(self.messages) == 0 and not testmode:
- raise ValueError(1, 'Missing JSON message definitions')
+ 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))
- # Register error handler
- if not testmode:
- vpp_api.vac_set_error_handler(vac_error_handler)
-
- # Support legacy CFFI
- # from_buffer supported from 1.8.0
- (major, minor, patch) = [int(s) for s in
- cffi.__version__.split('.', 3)]
- if major >= 1 and minor >= 8:
- self._write = self._write_new_cffi
- else:
- self._write = self._write_legacy_cffi
-
class ContextId(object):
"""Thread-safe provider of unique context IDs."""
def __init__(self):
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
: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'])
+ dirs = [cls.apidir] if cls.apidir else []
# 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
# 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
+ # check the directories for existence; first one wins
for dir in dirs:
if os.path.isdir(dir):
return dir
if api_dir is None:
api_dir = cls.find_api_dir()
if api_dir is None:
- raise RuntimeError("api_dir cannot be located")
+ raise VPPApiError("api_dir cannot be located")
if isinstance(patterns, list) or isinstance(patterns, tuple):
patterns = [p.strip() + '.api.json' for p in patterns]
return api_files
- 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))
-
@property
def api(self):
if not hasattr(self, "_api"):
- raise Exception("Not connected, api definitions not available")
+ raise VPPApiError("Not connected, api definitions not available")
return self._api
def make_function(self, msg, i, multipart, do_async):
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._api = VppApiDynamicMethodHolder()
for name, msg in vpp_iterator(self.messages):
n = name + '_' + msg.crc[2:]
- i = vpp_api.vac_get_msg_index(n.encode())
+ i = self.transport.get_msg_index(n.encode('utf-8'))
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))
+
+ # 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 _write_new_cffi(self, buf):
- """Send a binary-packed message to VPP."""
- if not self.connected:
- raise IOError(1, 'Not connected')
- return vpp_api.vac_write(ffi.from_buffer(buf), len(buf))
-
- def _write_legacy_cffi(self, buf):
- """Send a binary-packed message to VPP."""
- if not self.connected:
- raise IOError(1, 'Not connected')
- return vpp_api.vac_write(bytes(buf), len(buf))
-
- def _read(self):
- if not self.connected:
- raise IOError(1, 'Not connected')
- mem = ffi.new("char **")
- size = ffi.new("int *")
- rv = vpp_api.vac_read(mem, size, self.read_timeout)
- if rv:
- raise IOError(rv, 'vac_read failed')
- msg = bytes(ffi.buffer(mem[0], size[0]))
- vpp_api.vac_free(mem[0])
- return msg
-
def connect_internal(self, name, msg_handler, chroot_prefix, rx_qlen,
do_async):
- pfx = chroot_prefix.encode() if chroot_prefix else ffi.NULL
- rv = vpp_api.vac_connect(name.encode(), pfx, msg_handler, rx_qlen)
+ 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 IOError(2, 'Connect failed')
- self.connected = True
- self.vpp_dictionary_maxid = vpp_api.vac_msg_table_max_index()
+ 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 = vpp_api.vac_get_msg_index(
- ('control_ping' + '_' + crc[2:]).encode())
+ 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()
+ else:
+ self.event_thread = None
return rv
def connect(self, name, chroot_prefix=None, do_async=False, rx_qlen=32):
rx_qlen - the length of the VPP message receive queue between
client and server.
"""
- msg_handler = vac_callback_sync if not do_async else vac_callback_async
+ msg_handler = self.transport.get_callback(do_async)
return self.connect_internal(name, msg_handler, chroot_prefix, rx_qlen,
do_async)
client and server.
"""
- return self.connect_internal(name, ffi.NULL, chroot_prefix, rx_qlen,
+ return self.connect_internal(name, None, chroot_prefix, rx_qlen,
do_async=False)
def disconnect(self):
"""Detach from VPP."""
- rv = vpp_api.vac_disconnect()
- self.connected = False
- self.message_queue.put("terminate event thread")
+ rv = self.transport.disconnect()
+ if self.event_thread is not None:
+ self.message_queue.put("terminate event thread")
return rv
def msg_handler_sync(self, msg):
# 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')
+ 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']])
- def decode_incoming_msg(self, msg):
+ (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
#
msgobj = self.id_msgdef[i]
if not msgobj:
- raise IOError(2, 'Reply message undefined')
+ raise VPPIOError(2, 'Reply message undefined')
- r, size = msgobj.unpack(msg)
+ r, size = msgobj.unpack(msg, ntc=no_type_conversion)
return r
def msg_handler_async(self, msg):
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))
+ raise VPPValueError('Invalid argument {} to {}'
+ .format(list(d), msg.name))
- def _call_vpp(self, i, msg, multipart, **kwargs):
+ def _call_vpp(self, i, msgdef, multipart, **kwargs):
"""Given a message, send the message and await a reply.
msgdef - the message packing definition
context = kwargs['context']
kwargs['_vl_msg_id'] = i
- self.validate_args(msg, kwargs)
- b = msg.pack(kwargs)
- vpp_api.vac_rx_suspend()
- self._write(b)
+ 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
# Block until we get a reply.
rl = []
while (True):
- msg = self._read()
+ msg = self.transport.read()
if not msg:
- raise IOError(2, 'VPP API client: read failed')
- r = self.decode_incoming_msg(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
rl.append(r)
- vpp_api.vac_rx_resume()
+ self.transport.resume()
+ logger.debug(return_logger(rl))
return rl
def _call_vpp_async(self, i, msg, **kwargs):
kwargs['context'] = context
else:
context = kwargs['context']
- kwargs['client_index'] = 0
+ 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._write(b)
+ self.transport.write(b)
def register_event_callback(self, callback):
"""Register a callback for async messages.
self.event_callback = callback
def thread_msg_handler(self):
- """Python thread calling the user registerd message handler.
+ """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
if self.event_callback:
self.event_callback(msgname, r)
+# Provide the old name for backward compatibility.
+VPP = VPPApiClient
# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4