api: provide api definition over api
[vpp.git] / src / vpp-api / python / vpp_papi / vpp_papi.py
index 4afb616..30c00cd 100644 (file)
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Copyright (c) 2016 Cisco and/or its affiliates.
 # Licensed under the Apache License, Version 2.0 (the "License");
 #
 # Copyright (c) 2016 Cisco and/or its affiliates.
 # Licensed under the Apache License, Version 2.0 (the "License");
 
 from __future__ import print_function
 from __future__ import absolute_import
 
 from __future__ import print_function
 from __future__ import absolute_import
-import sys
+import ctypes
+import ipaddress
+import multiprocessing as mp
 import os
 import os
+import queue
 import logging
 import logging
-import collections
-import struct
+import functools
 import json
 import threading
 import fnmatch
 import weakref
 import atexit
 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
-
-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);
-
-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')
-
+import time
+import pkg_resources
+from .vpp_format import verify_enum_hint
+from .vpp_serializer import VPPType, VPPEnumType, VPPEnumFlagType, VPPUnionType
+from .vpp_serializer import VPPMessage, vpp_get_type, VPPTypeAlias
+
+try:
+    import VppTransport
+except ModuleNotFoundError:
+
+    class V:
+        """placeholder for VppTransport as the implementation is dependent on
+        VPPAPIClient's initialization values
+        """
 
 
-def vpp_atexit(vpp_weakref):
-    """Clean up VPP connection on shutdown."""
-    vpp_instance = vpp_weakref()
-    if vpp_instance.connected:
-        vpp_instance.logger.debug('Cleaning up VPP on exit')
-        vpp_instance.disconnect()
+    VppTransport = V
 
 
+from .vpp_transport_socket import VppTransport
 
 
-vpp_object = None
+logger = logging.getLogger("vpp_papi")
+logger.addHandler(logging.NullHandler())
 
 
+__all__ = (
+    "FuncWrapper",
+    "VppApiDynamicMethodHolder",
+    "VppEnum",
+    "VppEnumType",
+    "VppEnumFlag",
+    "VPPIOError",
+    "VPPRuntimeError",
+    "VPPValueError",
+    "VPPApiClient",
+)
 
 
-def vpp_iterator(d):
-    if sys.version[0] == '2':
-        return d.iteritems()
-    else:
-        return d.items()
 
 
+def metaclass(metaclass):
+    @functools.wraps(metaclass)
+    def wrapper(cls):
+        return metaclass(cls.__name__, cls.__bases__, cls.__dict__.copy())
 
 
-@ffi.callback("void(unsigned char *, int)")
-def vac_callback_sync(data, len):
-    vpp_object.msg_handler_sync(ffi.buffer(data, len))
+    return wrapper
 
 
 
 
-@ffi.callback("void(unsigned char *, int)")
-def vac_callback_async(data, len):
-    vpp_object.msg_handler_async(ffi.buffer(data, len))
+class VppEnumType(type):
+    def __getattr__(cls, name):
+        t = vpp_get_type(name)
+        return t.enum
 
 
 
 
-@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))
+@metaclass(VppEnumType)
+class VppEnum:
+    pass
 
 
 
 
-class VppApiDynamicMethodHolder(object):
+@metaclass(VppEnumType)
+class VppEnumFlag:
     pass
 
 
     pass
 
 
-class FuncWrapper(object):
-    def __init__(self, func):
-        self._func = func
-        self.__name__ = func.__name__
-
-    def __call__(self, **kwargs):
-        return self._func(**kwargs)
+def vpp_atexit(vpp_weakref):
+    """Clean up VPP connection on shutdown."""
+    vpp_instance = vpp_weakref()
+    if vpp_instance and vpp_instance.transport.connected:
+        logger.debug("Cleaning up VPP on exit")
+        vpp_instance.disconnect()
 
 
 
 
-class VPP():
-    """VPP interface.
+def add_convenience_methods():
+    # provide convenience methods to IP[46]Address.vapi_af
+    def _vapi_af(self):
+        if 6 == self._version:
+            return VppEnum.vl_api_address_family_t.ADDRESS_IP6.value
+        if 4 == self._version:
+            return VppEnum.vl_api_address_family_t.ADDRESS_IP4.value
+        raise ValueError("Invalid _version.")
 
 
-    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.
+    def _vapi_af_name(self):
+        if 6 == self._version:
+            return "ip6"
+        if 4 == self._version:
+            return "ip4"
+        raise ValueError("Invalid _version.")
 
 
-    Additionally, VPP can send callback messages; this class
-    provides a means to register a callback function to receive
-    these messages in a background thread.
-    """
+    ipaddress._IPAddressBase.vapi_af = property(_vapi_af)
+    ipaddress._IPAddressBase.vapi_af_name = property(_vapi_af_name)
 
 
-    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 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
+class VppApiDynamicMethodHolder:
+    pass
 
 
-        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=0):
-        """Create a VPP API object.
+class FuncWrapper:
+    def __init__(self, func):
+        self._func = func
+        self.__name__ = func.__name__
+        self.__doc__ = func.__doc__
 
 
-        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.
+    def __call__(self, **kwargs):
+        return self._func(**kwargs)
 
 
-        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).
-        """
-        global vpp_object
-        vpp_object = self
+    def __repr__(self):
+        return "<FuncWrapper(func=<%s(%s)>)>" % (self.__name__, self.__doc__)
 
 
-        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.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
+class VPPApiError(Exception):
+    pass
 
 
-        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)
+class VPPNotImplementedError(NotImplementedError):
+    pass
 
 
-        self.apifiles = apifiles
 
 
-        # Basic sanity check
-        if len(self.messages) == 0 and not testmode:
-            raise ValueError(1, 'Missing JSON message definitions')
+class VPPIOError(IOError):
+    pass
 
 
-        # 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)
+class VPPRuntimeError(RuntimeError):
+    pass
 
 
-        # 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):
-            self.context = 0
-            self.lock = threading.Lock()
+class VPPValueError(ValueError):
+    pass
 
 
-        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()
 
 
+class VPPApiJSONFiles:
     @classmethod
     @classmethod
-    def find_api_dir(cls):
+    def find_api_dir(cls, dirs=[]):
         """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
         """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
@@ -265,15 +165,15 @@ class VPP():
         :returns: A single directory name, or None if no such directory
             could be found.
         """
         :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
 
         # 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__'):
+
+        if os.getenv("VPP_API_DIR"):
+            dirs.append(os.getenv("VPP_API_DIR"))
+
+        if hasattr(main, "__file__"):
             # get the path of the calling script
             localdir = os.path.dirname(os.path.realpath(main.__file__))
         else:
             # get the path of the calling script
             localdir = os.path.dirname(os.path.realpath(main.__file__))
         else:
@@ -283,7 +183,7 @@ class VPP():
 
         def dmatch(dir):
             """Match dir against right-hand components of the script dir"""
 
         def dmatch(dir):
             """Match dir against right-hand components of the script dir"""
-            d = dir.split('/')  # param 'dir' assumes a / separator
+            d = dir.split("/")  # param 'dir' assumes a / separator
             length = len(d)
             return len(localdir_s) > length and localdir_s[-length:] == d
 
             length = len(d)
             return len(localdir_s) > length and localdir_s[-length:] == d
 
@@ -292,45 +192,47 @@ class VPP():
             'variant'  (typically '' or '_debug')"""
             # Since 'core' and 'plugin' files are staged
             # in separate directories, we target the parent dir.
             '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',
-            ))
+            return os.path.sep.join(
+                (
+                    srcdir,
+                    "build-root",
+                    "install-vpp%s-native" % variant,
+                    "vpp",
+                    "share",
+                    "vpp",
+                    "api",
+                )
+            )
 
         srcdir = None
 
         srcdir = None
-        if dmatch('src/scripts'):
+        if dmatch("src/scripts"):
             srcdir = os.path.sep.join(localdir_s[:-2])
             srcdir = os.path.sep.join(localdir_s[:-2])
-        elif dmatch('src/vpp-api/python'):
+        elif dmatch("src/vpp-api/python"):
             srcdir = os.path.sep.join(localdir_s[:-3])
             srcdir = os.path.sep.join(localdir_s[:-3])
-        elif dmatch('test'):
+        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.
             # 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, ''))
+            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
 
         # 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'):
+        if dmatch("build-root/install-vpp_debug-native/vpp/bin"):
             srcdir = os.path.sep.join(localdir_s[:-4])
             srcdir = os.path.sep.join(localdir_s[:-4])
-            dirs.append(sdir(srcdir, '_debug'))
-        if dmatch('build-root/install-vpp-native/vpp/bin'):
+            dirs.append(sdir(srcdir, "_debug"))
+        if dmatch("build-root/install-vpp-native/vpp/bin"):
             srcdir = os.path.sep.join(localdir_s[:-4])
             srcdir = os.path.sep.join(localdir_s[:-4])
-            dirs.append(sdir(srcdir, ''))
+            dirs.append(sdir(srcdir, ""))
 
         # finally, try the location system packages typically install into
 
         # finally, try the location system packages typically install into
-        dirs.append(os.path.sep.join(('', 'usr', 'share', 'vpp', 'api')))
+        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
         for dir in dirs:
             if os.path.isdir(dir):
                 return dir
@@ -338,7 +240,7 @@ class VPP():
         return None
 
     @classmethod
         return None
 
     @classmethod
-    def find_api_files(cls, api_dir=None, patterns='*'):
+    def find_api_files(cls, api_dir=None, patterns="*"):  # -> list
         """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
         """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
@@ -359,14 +261,14 @@ class VPP():
         :returns: A list of file paths for the API files found.
         """
         if api_dir is None:
         :returns: A list of file paths for the API files found.
         """
         if api_dir is None:
-            api_dir = cls.find_api_dir()
+            api_dir = cls.find_api_dir([])
             if api_dir is None:
             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):
 
         if isinstance(patterns, list) or isinstance(patterns, tuple):
-            patterns = [p.strip() + '.api.json' for p in patterns]
+            patterns = [p.strip() + ".api.json" for p in patterns]
         else:
         else:
-            patterns = [p.strip() + '.api.json' for p in patterns.split(",")]
+            patterns = [p.strip() + ".api.json" for p in patterns.split(",")]
 
         api_files = []
         for root, dirnames, files in os.walk(api_dir):
 
         api_files = []
         for root, dirnames, files in os.walk(api_dir):
@@ -377,93 +279,366 @@ class VPP():
 
         return api_files
 
 
         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))
+    @classmethod
+    def process_json_file(self, apidef_file):
+        api = json.load(apidef_file)
+        return self._process_json(api)
+
+    @classmethod
+    def process_json_str(self, json_str):
+        api = json.loads(json_str)
+        return self._process_json(api)
+
+    @classmethod
+    def process_json_array_str(self, json_str):
+        services = {}
+        messages = {}
+
+        apis = json.loads(json_str)
+        for a in apis:
+            m, s = self._process_json(a)
+            messages.update(m)
+            services.update(s)
+        return messages, services
+
+    @staticmethod
+    def _process_json(api):  # -> Tuple[Dict, Dict]
+        types = {}
+        services = {}
+        messages = {}
+        try:
+            for t in api["enums"]:
+                t[0] = "vl_api_" + t[0] + "_t"
+                types[t[0]] = {"type": "enum", "data": t}
+        except KeyError:
+            pass
+        try:
+            for t in api["enumflags"]:
+                t[0] = "vl_api_" + t[0] + "_t"
+                types[t[0]] = {"type": "enum", "data": t}
+        except KeyError:
+            pass
+        try:
+            for t in api["unions"]:
+                t[0] = "vl_api_" + t[0] + "_t"
+                types[t[0]] = {"type": "union", "data": t}
+        except KeyError:
+            pass
+
+        try:
+            for t in api["types"]:
+                t[0] = "vl_api_" + t[0] + "_t"
+                types[t[0]] = {"type": "type", "data": t}
+        except KeyError:
+            pass
+
+        try:
+            for t, v in api["aliases"].items():
+                types["vl_api_" + t + "_t"] = {"type": "alias", "data": v}
+        except KeyError:
+            pass
+
+        try:
+            services.update(api["services"])
+        except KeyError:
+            pass
+
+        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
+                if not vpp_get_type(k):
+                    if v["type"] == "enumflag":
+                        try:
+                            VPPEnumFlagType(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
+        try:
+            for m in api["messages"]:
+                try:
+                    messages[m[0]] = VPPMessage(m[0], m[1:])
+                except VPPNotImplementedError:
+                    logger.error("Not implemented error for {}".format(m[0]))
+        except KeyError:
+            pass
+        return messages, services
+
+    @staticmethod
+    def load_api(apifiles=None, apidir=None):
+        messages = {}
+        services = {}
+        if not apifiles:
+            # Pick up API definitions from default directory
+            try:
+                if isinstance(apidir, list):
+                    apifiles = []
+                    for d in apidir:
+                        apifiles += VPPApiJSONFiles.find_api_files(d)
+                else:
+                    apifiles = VPPApiJSONFiles.find_api_files(apidir)
+            except (RuntimeError, VPPApiError):
+                raise VPPRuntimeError
+
+        for file in apifiles:
+            with open(file) as apidef_file:
+                m, s = VPPApiJSONFiles.process_json_file(apidef_file)
+                messages.update(m)
+                services.update(s)
+
+        return apifiles, messages, services
+
+
+class VPPApiClient:
+    """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 __init__(
+        self,
+        *,
+        apifiles=None,
+        apidir=None,
+        testmode=False,
+        async_thread=True,
+        logger=None,
+        loglevel=None,
+        read_timeout=5,
+        use_socket=True,
+        server_address="/run/vpp/api.sock",
+        bootstrapapi=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.
+
+        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(
+                "{}.{}".format(__name__, self.__class__.__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.apidir = apidir
+        self.event_callback = None
+        self.message_queue = queue.Queue()
+        self.read_timeout = read_timeout
+        self.async_thread = async_thread
+        self.event_thread = None
+        self.testmode = testmode
+        self.server_address = server_address
+        self._apifiles = apifiles
+        self.stats = {}
+        self.bootstrapapi = bootstrapapi
+
+        if not bootstrapapi:
+            if self.apidir is None and hasattr(self.__class__, "apidir"):
+                # Keep supporting the old style of providing apidir.
+                self.apidir = self.__class__.apidir
+            try:
+                self.apifiles, self.messages, self.services = VPPApiJSONFiles.load_api(
+                    apifiles, self.apidir
+                )
+            except VPPRuntimeError as e:
+                if testmode:
+                    self.apifiles = []
+                else:
+                    raise e
+        else:
+            # Bootstrap the API (memclnt.api bundled with VPP PAPI)
+            resource_path = "/".join(("data", "memclnt.api.json"))
+            file_content = pkg_resources.resource_string(__name__, resource_path)
+            self.messages, self.services = VPPApiJSONFiles.process_json_str(
+                file_content
+            )
+
+        # Basic sanity check
+        if len(self.messages) == 0 and not testmode:
+            raise VPPValueError(1, "Missing JSON message definitions")
+        if not bootstrapapi:
+            if not (verify_enum_hint(VppEnum.vl_api_address_family_t)):
+                raise VPPRuntimeError(
+                    "Invalid address family hints. " "Cannot continue."
+                )
+
+        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))
+
+        add_convenience_methods()
+
+    def get_function(self, name):
+        return getattr(self._api, name)
+
+    class ContextId:
+        """Multiprocessing-safe provider of unique context IDs."""
+
+        def __init__(self):
+            self.context = mp.Value(ctypes.c_uint, 0)
+            self.lock = mp.Lock()
+
+        def __call__(self):
+            """Get a new unique (or, at least, not recently used) context."""
+            with self.lock:
+                self.context.value += 1
+                return self.context.value
+
+    get_context = ContextId()
+
+    def get_type(self, name):
+        return vpp_get_type(name)
 
     @property
     def api(self):
         if not hasattr(self, "_api"):
 
     @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):
         return self._api
 
     def make_function(self, msg, i, multipart, do_async):
-        if (do_async):
+        if do_async:
+
             def f(**kwargs):
                 return self._call_vpp_async(i, msg, **kwargs)
             def f(**kwargs):
                 return self._call_vpp_async(i, msg, **kwargs)
+
         else:
         else:
+
             def f(**kwargs):
                 return self._call_vpp(i, msg, multipart, **kwargs)
 
         f.__name__ = str(msg.name)
             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.__doc__ = ", ".join(
+            ["%s %s" % (msg.fieldtypes[j], k) for j, k in enumerate(msg.fields)]
+        )
+        f.msg = msg
+
+        return f
+
+    def make_pack_function(self, msg, i, multipart):
+        def f(**kwargs):
+            return self._call_vpp_pack(i, msg, **kwargs)
+
+        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()
         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 = vpp_api.vac_get_msg_index(n.encode())
+        for name, msg in self.messages.items():
+            n = name + "_" + msg.crc[2:]
+            i = self.transport.get_msg_index(n)
             if i > 0:
                 self.id_msgdef[i] = msg
                 self.id_names[i] = name
             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:
+                    f = self.make_function(msg, i, self.services[name], do_async)
+                    f_pack = self.make_pack_function(msg, i, self.services[name])
+                    setattr(self._api, name, FuncWrapper(f))
+                    setattr(self._api, name + "_pack", FuncWrapper(f_pack))
             else:
             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)
+                self.logger.debug("No such message type or failed CRC checksum: %s", n)
+
+    def get_api_definitions(self):
+        """get_api_definition. Bootstrap from the embedded memclnt.api.json file."""
+
+        # Bootstrap so we can call the get_api_json function
+        self._register_functions(do_async=False)
+
+        r = self.api.get_api_json()
+        if r.retval != 0:
+            raise VPPApiError("Failed to load API definitions from VPP")
+
+        # Process JSON
+        m, s = VPPApiJSONFiles.process_json_array_str(r.json)
+        self.messages.update(m)
+        self.services.update(s)
+
+    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, pfx, msg_handler, rx_qlen, do_async)
         if rv != 0:
         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()
+
+        # Register functions
+        if self.bootstrapapi:
+            self.get_api_definitions()
         self._register_functions(do_async=do_async)
 
         # Initialise control ping
         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_msgdef = self.messages['control_ping']
+        crc = self.messages["control_ping"].crc
+        self.control_ping_index = self.transport.get_msg_index(
+            ("control_ping" + "_" + crc[2:])
+        )
+        self.control_ping_msgdef = self.messages["control_ping"]
+
         if self.async_thread:
         if self.async_thread:
-            self.event_thread = threading.Thread(
-                target=self.thread_msg_handler)
+            self.event_thread = threading.Thread(target=self.thread_msg_handler)
             self.event_thread.daemon = True
             self.event_thread.start()
             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):
         return rv
 
     def connect(self, name, chroot_prefix=None, do_async=False, rx_qlen=32):
@@ -475,9 +650,10 @@ class VPP():
         rx_qlen - the length of the VPP message receive queue between
         client and server.
         """
         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
-        return self.connect_internal(name, msg_handler, chroot_prefix, rx_qlen,
-                                     do_async)
+        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.
 
     def connect_sync(self, name, chroot_prefix=None, rx_qlen=32):
         """Attach to VPP in synchronous mode. Application must poll for events.
@@ -488,14 +664,13 @@ class VPP():
         client and server.
         """
 
         client and server.
         """
 
-        return self.connect_internal(name, ffi.NULL, chroot_prefix, rx_qlen,
-                                     do_async=False)
+        return self.connect_internal(name, None, chroot_prefix, rx_qlen, do_async=False)
 
     def disconnect(self):
         """Detach from VPP."""
 
     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):
         return rv
 
     def msg_handler_sync(self, msg):
@@ -510,22 +685,44 @@ class VPP():
         # If we have a context, then use the context to find any
         # request waiting for a reply
         context = 0
         # 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:
+        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:
             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')
+            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):
+    def decode_incoming_msg(self, msg, no_type_conversion=False):
         if not msg:
         if not msg:
-            self.logger.warning('vpp_api.read failed')
+            logger.warning("vpp_api.read failed")
             return
 
             return
 
-        i, ci = self.header.unpack(msg, 0)
-        if self.id_names[i] == 'rx_thread_exit':
+        (i, ci), size = self.header.unpack(msg, 0)
+        if self.id_names[i] == "rx_thread_exit":
             return
 
         #
             return
 
         #
@@ -533,10 +730,9 @@ class VPP():
         #
         msgobj = self.id_msgdef[i]
         if not msgobj:
         #
         msgobj = self.id_msgdef[i]
         if not msgobj:
-            raise IOError(2, 'Reply message undefined')
-
-        r = msgobj.unpack(msg)
+            raise VPPIOError(2, "Reply message undefined")
 
 
+        r, size = msgobj.unpack(msg, ntc=no_type_conversion)
         return r
 
     def msg_handler_async(self, msg):
         return r
 
     def msg_handler_async(self, msg):
@@ -555,17 +751,42 @@ class VPP():
 
     def _control_ping(self, context):
         """Send a ping command."""
 
     def _control_ping(self, context):
         """Send a ping command."""
-        self._call_vpp_async(self.control_ping_index,
-                             self.control_ping_msgdef,
-                             context=context)
+        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:
 
     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 _add_stat(self, name, ms):
+        if not name in self.stats:
+            self.stats[name] = {"max": ms, "count": 1, "avg": ms}
+        else:
+            if ms > self.stats[name]["max"]:
+                self.stats[name]["max"] = ms
+            self.stats[name]["count"] += 1
+            n = self.stats[name]["count"]
+            self.stats[name]["avg"] = self.stats[name]["avg"] * (n - 1) / n + ms / n
+
+    def get_stats(self):
+        s = "\n=== API PAPI STATISTICS ===\n"
+        s += "{:<30} {:>4} {:>6} {:>6}\n".format("message", "cnt", "avg", "max")
+        for n in sorted(self.stats.items(), key=lambda v: v[1]["avg"], reverse=True):
+            s += "{:<30} {:>4} {:>6.2f} {:>6.2f}\n".format(
+                n[0], n[1]["count"], n[1]["avg"], n[1]["max"]
+            )
+        return s
+
+    def get_field_options(self, msg, fld_name):
+        # when there is an option, the msgdef has 3 elements.
+        # ['u32', 'ring_size', {'default': 1024}]
+        for _def in self.messages[msg].msgdef:
+            if isinstance(_def, list) and len(_def) == 3 and _def[1] == fld_name:
+                return _def[2]
+
+    def _call_vpp(self, i, msgdef, service, **kwargs):
         """Given a message, send the message and await a reply.
 
         msgdef - the message packing definition
         """Given a message, send the message and await a reply.
 
         msgdef - the message packing definition
@@ -580,67 +801,146 @@ class VPP():
         the response.  It will raise an IOError exception if there was
         no response within the timeout window.
         """
         the response.  It will raise an IOError exception if there was
         no response within the timeout window.
         """
-
-        if 'context' not in kwargs:
+        ts = time.time()
+        if "context" not in kwargs:
             context = self.get_context()
             context = self.get_context()
-            kwargs['context'] = context
+            kwargs["context"] = context
         else:
         else:
-            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)
-
-        if multipart:
-            # Send a ping after the request - we use its response
-            # to detect that we have seen all results.
-            self._control_ping(context)
+            context = kwargs["context"]
+        kwargs["_vl_msg_id"] = i
+
+        no_type_conversion = kwargs.pop("_no_type_conversion", False)
+        timeout = kwargs.pop("_timeout", None)
+
+        try:
+            if self.transport.socket_index:
+                kwargs["client_index"] = self.transport.socket_index
+        except AttributeError:
+            pass
+        self.validate_args(msgdef, kwargs)
+
+        s = "Calling {}({})".format(
+            msgdef.name, ",".join(["{!r}:{!r}".format(k, v) for k, v in kwargs.items()])
+        )
+        self.logger.debug(s)
+
+        b = msgdef.pack(kwargs)
+        self.transport.suspend()
+
+        self.transport.write(b)
+
+        msgreply = service["reply"]
+        stream = True if "stream" in service else False
+        if stream:
+            if "stream_msg" in service:
+                # New service['reply'] = _reply and service['stream_message'] = _details
+                stream_message = service["stream_msg"]
+                modern = True
+            else:
+                # Old  service['reply'] = _details
+                stream_message = msgreply
+                msgreply = "control_ping_reply"
+                modern = False
+                # 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 = []
 
         # Block until we get a reply.
         rl = []
-        while (True):
-            msg = self._read()
-            if not msg:
-                raise IOError(2, 'VPP API client: read failed')
-            r = self.decode_incoming_msg(msg)
+        while True:
+            r = self.read_blocking(no_type_conversion, timeout)
+            if r is None:
+                raise VPPIOError(2, "VPP API client: read failed")
             msgname = type(r).__name__
             if context not in r or r.context == 0 or context != r.context:
             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
                 self.message_queue.put_nowait(r)
                 continue
-
-            if not multipart:
+            if msgname != msgreply and (stream and (msgname != stream_message)):
+                print("REPLY MISMATCH", msgreply, msgname, stream_message, stream)
+            if not stream:
                 rl = r
                 break
                 rl = r
                 break
-            if msgname == 'control_ping_reply':
+            if msgname == msgreply:
+                if modern:  # Return both reply and list
+                    rl = r, rl
                 break
 
             rl.append(r)
 
                 break
 
             rl.append(r)
 
-        vpp_api.vac_rx_resume()
+        self.transport.resume()
 
 
+        s = "Return value: {!r}".format(r)
+        if len(s) > 80:
+            s = s[:80] + "..."
+        self.logger.debug(s)
+        te = time.time()
+        self._add_stat(msgdef.name, (te - ts) * 1000)
         return rl
 
     def _call_vpp_async(self, i, msg, **kwargs):
         return rl
 
     def _call_vpp_async(self, i, msg, **kwargs):
-        """Given a message, send the message and await a reply.
+        """Given a message, send the message and return the context.
 
         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.
 
         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.
+
+        The reply message(s) will be delivered later to the registered callback.
+        The returned context will help with assigning which call
+        the reply belongs to.
         """
         """
-        if 'context' not in kwargs:
+        if "context" not in kwargs:
             context = self.get_context()
             context = self.get_context()
-            kwargs['context'] = context
+            kwargs["context"] = context
         else:
         else:
-            context = kwargs['context']
-        kwargs['client_index'] = 0
-        kwargs['_vl_msg_id'] = i
+            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)
 
         b = msg.pack(kwargs)
 
-        self._write(b)
+        self.transport.write(b)
+        return context
+
+    def _call_vpp_pack(self, i, msg, **kwargs):
+        """Given a message, return the binary representation."""
+        kwargs["_vl_msg_id"] = i
+        kwargs["client_index"] = 0
+        kwargs["context"] = 0
+        return msg.pack(kwargs)
+
+    def read_blocking(self, no_type_conversion=False, timeout=None):
+        """Get next received message from transport within timeout, decoded.
+
+        Note that notifications have context zero
+        and are not put into receive queue (at least for socket transport),
+        use async_thread with registered callback for processing them.
+
+        If no message appears in the queue within timeout, return None.
+
+        Optionally, type conversion can be skipped,
+        as some of conversions are into less precise types.
+
+        When r is the return value of this, the caller can get message name as:
+            msgname = type(r).__name__
+        and context number (type long) as:
+            context = r.context
+
+        :param no_type_conversion: If false, type conversions are applied.
+        :type no_type_conversion: bool
+        :returns: Decoded message, or None if no message (within timeout).
+        :rtype: Whatever VPPType.unpack returns, depends on no_type_conversion.
+        :raises VppTransportShmemIOError if timed out.
+        """
+        msg = self.transport.read(timeout=timeout)
+        if not msg:
+            return None
+        return self.decode_incoming_msg(msg, no_type_conversion)
 
     def register_event_callback(self, callback):
         """Register a callback for async messages.
 
     def register_event_callback(self, callback):
         """Register a callback for async messages.
@@ -661,7 +961,7 @@ class VPP():
         self.event_callback = callback
 
     def thread_msg_handler(self):
         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
 
         This is to emulate the old style event callback scheme. Modern
         clients should provide their own thread to poll the event
@@ -675,5 +975,56 @@ class VPP():
             if self.event_callback:
                 self.event_callback(msgname, r)
 
             if self.event_callback:
                 self.event_callback(msgname, r)
 
-
-# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4
+    def validate_message_table(self, namecrctable):
+        """Take a dictionary of name_crc message names
+        and returns an array of missing messages"""
+
+        missing_table = []
+        for name_crc in namecrctable:
+            i = self.transport.get_msg_index(name_crc)
+            if i <= 0:
+                missing_table.append(name_crc)
+        return missing_table
+
+    def dump_message_table(self):
+        """Return VPPs API message table as name_crc dictionary"""
+        return self.transport.message_table
+
+    def dump_message_table_filtered(self, msglist):
+        """Return VPPs API message table as name_crc dictionary,
+        filtered by message name list."""
+
+        replies = [self.services[n]["reply"] for n in msglist]
+        message_table_filtered = {}
+        for name in msglist + replies:
+            for k, v in self.transport.message_table.items():
+                if k.startswith(name):
+                    message_table_filtered[k] = v
+                    break
+        return message_table_filtered
+
+    def __repr__(self):
+        return (
+            "<VPPApiClient apifiles=%s, testmode=%s, async_thread=%s, "
+            "logger=%s, read_timeout=%s, "
+            "server_address='%s'>"
+            % (
+                self._apifiles,
+                self.testmode,
+                self.async_thread,
+                self.logger,
+                self.read_timeout,
+                self.server_address,
+            )
+        )
+
+    def details_iter(self, f, **kwargs):
+        cursor = 0
+        while True:
+            kwargs["cursor"] = cursor
+            rv, details = f(**kwargs)
+            for d in details:
+                yield d
+            if rv.retval == 0 or rv.retval != -165:
+                break
+            cursor = rv.cursor