src/vpp-api/vapi/vapi_json_parser.py

   1 #!/usr/bin/env python3
   2
   3 import json
   4
   5
   6 class ParseError(Exception):
   7     pass
   8
   9
  10 magic_prefix = "vl_api_"
  11 magic_suffix = "_t"
  12
  13
  14 def remove_magic(what):
  15     if what.startswith(magic_prefix) and what.endswith(magic_suffix):
  16         return what[len(magic_prefix) : -len(magic_suffix)]
  17     return what
  18
  19
  20 class Field(object):
  21     def __init__(self, field_name, field_type, array_len=None, nelem_field=None):
  22         self.name = field_name
  23         self.type = field_type
  24         self.len = array_len
  25         self.nelem_field = nelem_field
  26
  27     def __str__(self):
  28         if self.len is None:
  29             return "Field(name: %s, type: %s)" % (self.name, self.type)
  30         elif type(self.len) == dict:
  31             return "Field(name: %s, type: %s, length: %s)" % (
  32                 self.name,
  33                 self.type,
  34                 self.len,
  35             )
  36         elif self.len > 0:
  37             return "Field(name: %s, type: %s, length: %s)" % (
  38                 self.name,
  39                 self.type,
  40                 self.len,
  41             )
  42         else:
  43             return "Field(name: %s, type: %s, variable length stored in: %s)" % (
  44                 self.name,
  45                 self.type,
  46                 self.nelem_field,
  47             )
  48
  49     def is_vla(self):
  50         return self.nelem_field is not None
  51
  52     def has_vla(self):
  53         return self.is_vla() or self.type.has_vla()
  54
  55
  56 class Alias(Field):
  57     pass
  58
  59
  60 class Type(object):
  61     def __init__(self, name):
  62         self.name = name
  63
  64     def __str__(self):
  65         return self.name
  66
  67
  68 class SimpleType(Type):
  69     def has_vla(self):
  70         return False
  71
  72
  73 def get_msg_header_defs(struct_type_class, field_class, json_parser, logger):
  74     return [
  75         struct_type_class(
  76             [
  77                 "msg_header1_t",
  78                 ["u16", "_vl_msg_id"],
  79                 ["u32", "context"],
  80             ],
  81             json_parser,
  82             field_class,
  83             logger,
  84         ),
  85         struct_type_class(
  86             [
  87                 "msg_header2_t",
  88                 ["u16", "_vl_msg_id"],
  89                 ["u32", "client_index"],
  90                 ["u32", "context"],
  91             ],
  92             json_parser,
  93             field_class,
  94             logger,
  95         ),
  96     ]
  97
  98
  99 class Struct(object):
 100     def __init__(self, name, fields):
 101         self.name = name
 102         self.fields = fields
 103         self.field_names = [n.name for n in self.fields]
 104         self.depends = [f.type for f in self.fields]
 105
 106     def __str__(self):
 107         return "[%s]" % "], [".join([str(f) for f in self.fields])
 108
 109     def has_vla(self):
 110         for f in self.fields:
 111             if f.has_vla():
 112                 return True
 113         return False
 114
 115
 116 class Enum(SimpleType):
 117     def __init__(self, name, value_pairs, enumtype):
 118         super(Enum, self).__init__(name)
 119         self.type = enumtype
 120         self.value_pairs = value_pairs
 121
 122     def __str__(self):
 123         return "Enum(%s, [%s])" % (
 124             self.name,
 125             "], [".join(["%s => %s" % (i, j) for i, j in self.value_pairs]),
 126         )
 127
 128
 129 class Union(Type):
 130     def __init__(self, name, type_pairs, crc):
 131         Type.__init__(self, name)
 132         self.crc = crc
 133         self.type_pairs = type_pairs
 134         self.depends = [t for t, _ in self.type_pairs]
 135
 136     def __str__(self):
 137         return "Union(%s, [%s])" % (
 138             self.name,
 139             "], [".join(["%s %s" % (i, j) for i, j in self.type_pairs]),
 140         )
 141
 142     def has_vla(self):
 143         return False
 144
 145
 146 class Message(object):
 147     def __init__(self, logger, definition, json_parser):
 148         struct_type_class = json_parser.struct_type_class
 149         field_class = json_parser.field_class
 150         self.request = None
 151         self.logger = logger
 152         m = definition
 153         logger.debug("Parsing message definition `%s'" % m)
 154         name = m[0]
 155         self.name = name
 156         logger.debug("Message name is `%s'" % name)
 157         ignore = True
 158         self.header = None
 159         self.is_reply = json_parser.is_reply(self.name)
 160         self.is_event = json_parser.is_event(self.name)
 161         self.is_stream = json_parser.is_stream(self.name)
 162         fields = []
 163         for header in get_msg_header_defs(
 164             struct_type_class, field_class, json_parser, logger
 165         ):
 166             logger.debug("Probing header `%s'" % header.name)
 167             if header.is_part_of_def(m[1:]):
 168                 self.header = header
 169                 logger.debug("Found header `%s'" % header.name)
 170                 fields.append(field_class(field_name="header", field_type=self.header))
 171                 ignore = False
 172                 break
 173         if ignore and not self.is_event and not self.is_reply:
 174             raise ParseError(
 175                 "While parsing message `%s': could not find all "
 176                 "common header fields" % name
 177             )
 178         for field in m[1:]:
 179             if isinstance(field, dict) and "crc" in field:
 180                 self.crc = field["crc"]
 181                 logger.debug("Found CRC `%s'" % self.crc)
 182                 continue
 183             else:
 184                 field_type = json_parser.lookup_type_like_id(field[0])
 185                 logger.debug("Parsing message field `%s'" % field)
 186                 l = len(field)
 187                 if any(type(n) is dict for n in field):
 188                     l -= 1
 189                 if l == 2:
 190                     if self.header is not None and self.header.has_field(field[1]):
 191                         continue
 192                     p = field_class(field_name=field[1], field_type=field_type)
 193                 elif l == 3:
 194                     if field[2] == 0 and field[0] != "string":
 195                         raise ParseError(
 196                             "While parsing message `%s': variable length "
 197                             "array `%s' doesn't have reference to member "
 198                             "containing the actual length" % (name, field[1])
 199                         )
 200                     if field[0] == "string" and field[2] > 0:
 201                         field_type = json_parser.lookup_type_like_id("u8")
 202
 203                     p = field_class(
 204                         field_name=field[1], field_type=field_type, array_len=field[2]
 205                     )
 206                 elif l == 4:
 207                     nelem_field = None
 208                     for f in fields:
 209                         if f.name == field[3]:
 210                             nelem_field = f
 211                     if nelem_field is None:
 212                         raise ParseError(
 213                             "While parsing message `%s': couldn't find "
 214                             "variable length array `%s' member containing "
 215                             "the actual length `%s'" % (name, field[1], field[3])
 216                         )
 217                     p = field_class(
 218                         field_name=field[1],
 219                         field_type=field_type,
 220                         array_len=field[2],
 221                         nelem_field=nelem_field,
 222                     )
 223                 else:
 224                     raise Exception(
 225                         "Don't know how to parse message "
 226                         "definition for message `%s': `%s'" % (m, m[1:])
 227                     )
 228                 logger.debug("Parsed field `%s'" % p)
 229                 fields.append(p)
 230         self.fields = fields
 231         self.depends = [f.type for f in self.fields]
 232         logger.debug("Parsed message: %s" % self)
 233
 234     def __str__(self):
 235         return "Message(%s, [%s], {crc: %s}" % (
 236             self.name,
 237             "], [".join([str(f) for f in self.fields]),
 238             self.crc,
 239         )
 240
 241
 242 class StructType(Type, Struct):
 243     def __init__(self, definition, json_parser, field_class, logger):
 244         t = definition
 245         logger.debug("Parsing struct definition `%s'" % t)
 246         name = t[0]
 247         fields = []
 248         for field in t[1:]:
 249             if len(field) == 1 and "crc" in field:
 250                 self.crc = field["crc"]
 251                 continue
 252             field_type = json_parser.lookup_type_like_id(field[0])
 253             logger.debug("Parsing type field `%s'" % field)
 254             if len(field) == 2:
 255                 p = field_class(field_name=field[1], field_type=field_type)
 256             elif len(field) == 3:
 257                 if field[2] == 0:
 258                     raise ParseError(
 259                         "While parsing type `%s': array `%s' has "
 260                         "variable length" % (name, field[1])
 261                     )
 262                 p = field_class(
 263                     field_name=field[1], field_type=field_type, array_len=field[2]
 264                 )
 265             elif len(field) == 4:
 266                 nelem_field = None
 267                 for f in fields:
 268                     if f.name == field[3]:
 269                         nelem_field = f
 270                 if nelem_field is None:
 271                     raise ParseError(
 272                         "While parsing message `%s': couldn't find "
 273                         "variable length array `%s' member containing "
 274                         "the actual length `%s'" % (name, field[1], field[3])
 275                     )
 276                 p = field_class(
 277                     field_name=field[1],
 278                     field_type=field_type,
 279                     array_len=field[2],
 280                     nelem_field=nelem_field,
 281                 )
 282             else:
 283                 raise ParseError(
 284                     "Don't know how to parse field `%s' of type definition "
 285                     "for type `%s'" % (field, t)
 286                 )
 287             fields.append(p)
 288         Type.__init__(self, name)
 289         Struct.__init__(self, name, fields)
 290
 291     def __str__(self):
 292         return "StructType(%s, %s)" % (Type.__str__(self), Struct.__str__(self))
 293
 294     def has_field(self, name):
 295         return name in self.field_names
 296
 297     def is_part_of_def(self, definition):
 298         for idx in range(len(self.fields)):
 299             field = definition[idx]
 300             p = self.fields[idx]
 301             if field[1] != p.name:
 302                 return False
 303             if field[0] != p.type.name:
 304                 raise ParseError(
 305                     "Unexpected field type `%s' (should be `%s'), "
 306                     "while parsing msg/def/field `%s/%s/%s'"
 307                     % (field[0], p.type, p.name, definition, field)
 308                 )
 309         return True
 310
 311
 312 class JsonParser(object):
 313     def __init__(
 314         self,
 315         logger,
 316         files,
 317         simple_type_class=SimpleType,
 318         enum_class=Enum,
 319         union_class=Union,
 320         struct_type_class=StructType,
 321         field_class=Field,
 322         message_class=Message,
 323         alias_class=Alias,
 324     ):
 325         self.services = {}
 326         self.messages = {}
 327         self.enums = {}
 328         self.enumflags = {}
 329         self.unions = {}
 330         self.aliases = {}
 331         self.types = {
 332             x: simple_type_class(x)
 333             for x in [
 334                 "i8",
 335                 "i16",
 336                 "i32",
 337                 "i64",
 338                 "u8",
 339                 "u16",
 340                 "u32",
 341                 "u64",
 342                 "f64",
 343                 "bool",
 344             ]
 345         }
 346
 347         self.types["string"] = simple_type_class("vl_api_string_t")
 348         self.replies = set()
 349         self.events = set()
 350         self.streams = set()
 351         self.simple_type_class = simple_type_class
 352         self.enum_class = enum_class
 353         self.union_class = union_class
 354         self.struct_type_class = struct_type_class
 355         self.field_class = field_class
 356         self.alias_class = alias_class
 357         self.message_class = message_class
 358
 359         self.exceptions = []
 360         self.json_files = []
 361         self.types_by_json = {}
 362         self.enums_by_json = {}
 363         self.unions_by_json = {}
 364         self.aliases_by_json = {}
 365         self.messages_by_json = {}
 366         self.logger = logger
 367         for f in files:
 368             self.parse_json_file(f)
 369         self.finalize_parsing()
 370
 371     def parse_json_file(self, path):
 372         self.logger.info("Parsing json api file: `%s'" % path)
 373         self.json_files.append(path)
 374         self.types_by_json[path] = []
 375         self.enums_by_json[path] = []
 376         self.unions_by_json[path] = []
 377         self.aliases_by_json[path] = []
 378         self.messages_by_json[path] = {}
 379         with open(path) as f:
 380             j = json.load(f)
 381             for k in j["services"]:
 382                 if k in self.services:
 383                     raise ParseError("Duplicate service `%s'" % k)
 384                 self.services[k] = j["services"][k]
 385                 self.replies.add(self.services[k]["reply"])
 386                 if "events" in self.services[k]:
 387                     for x in self.services[k]["events"]:
 388                         self.events.add(x)
 389                 if "stream_msg" in self.services[k]:
 390                     self.streams.add(self.services[k]["stream_msg"])
 391             for e in j["enums"]:
 392                 name = e[0]
 393                 value_pairs = e[1:-1]
 394                 enumtype = self.types[e[-1]["enumtype"]]
 395                 enum = self.enum_class(name, value_pairs, enumtype)
 396                 self.enums[enum.name] = enum
 397                 self.logger.debug("Parsed enum: %s" % enum)
 398                 self.enums_by_json[path].append(enum)
 399             for e in j["enumflags"]:
 400                 name = e[0]
 401                 value_pairs = e[1:-1]
 402                 enumtype = self.types[e[-1]["enumtype"]]
 403                 enum = self.enum_class(name, value_pairs, enumtype)
 404                 self.enums[enum.name] = enum
 405                 self.logger.debug("Parsed enumflag: %s" % enum)
 406                 self.enums_by_json[path].append(enum)
 407             exceptions = []
 408             progress = 0
 409             last_progress = 0
 410             while True:
 411                 for u in j["unions"]:
 412                     name = u[0]
 413                     if name in self.unions:
 414                         progress = progress + 1
 415                         continue
 416                     try:
 417                         type_pairs = [
 418                             [self.lookup_type_like_id(t), n] for t, n in u[1:]
 419                         ]
 420                         union = self.union_class(name, type_pairs, 0)
 421                         progress = progress + 1
 422                     except ParseError as e:
 423                         exceptions.append(e)
 424                         continue
 425                     self.unions[union.name] = union
 426                     self.logger.debug("Parsed union: %s" % union)
 427                     self.unions_by_json[path].append(union)
 428                 for t in j["types"]:
 429                     if t[0] in self.types:
 430                         progress = progress + 1
 431                         continue
 432                     try:
 433                         type_ = self.struct_type_class(
 434                             t, self, self.field_class, self.logger
 435                         )
 436                         if type_.name in self.types:
 437                             raise ParseError("Duplicate type `%s'" % type_.name)
 438                         progress = progress + 1
 439                     except ParseError as e:
 440                         exceptions.append(e)
 441                         continue
 442                     self.types[type_.name] = type_
 443                     self.types_by_json[path].append(type_)
 444                     self.logger.debug("Parsed type: %s" % type_)
 445                 for name, body in j["aliases"].items():
 446                     if name in self.aliases:
 447                         progress = progress + 1
 448                         continue
 449                     if "length" in body:
 450                         array_len = body["length"]
 451                     else:
 452                         array_len = None
 453                     try:
 454                         t = self.lookup_type_like_id(body["type"])
 455                     except ParseError as e:
 456                         exceptions.append(e)
 457                         continue
 458                     alias = self.alias_class(name, t, array_len)
 459                     self.aliases[name] = alias
 460                     self.logger.debug("Parsed alias: %s" % alias)
 461                     self.aliases_by_json[path].append(alias)
 462                 if not exceptions:
 463                     # finished parsing
 464                     break
 465                 if progress <= last_progress:
 466                     # cannot make forward progress
 467                     self.exceptions.extend(exceptions)
 468                     break
 469                 exceptions = []
 470                 last_progress = progress
 471                 progress = 0
 472             prev_length = len(self.messages)
 473             processed = []
 474             while True:
 475                 exceptions = []
 476                 for m in j["messages"]:
 477                     if m in processed:
 478                         continue
 479                     try:
 480                         msg = self.message_class(self.logger, m, self)
 481                         if msg.name in self.messages:
 482                             raise ParseError("Duplicate message `%s'" % msg.name)
 483                     except ParseError as e:
 484                         exceptions.append(e)
 485                         continue
 486                     self.messages[msg.name] = msg
 487                     self.messages_by_json[path][msg.name] = msg
 488                     processed.append(m)
 489                 if prev_length == len(self.messages):
 490                     # cannot make forward progress ...
 491                     self.exceptions.extend(exceptions)
 492                     break
 493                 prev_length = len(self.messages)
 494
 495     def lookup_type_like_id(self, name):
 496         mundane_name = remove_magic(name)
 497         if name in self.types:
 498             return self.types[name]
 499         elif name in self.enums:
 500             return self.enums[name]
 501         elif name in self.enumflags:
 502             return self.enumflags[name]
 503         elif name in self.unions:
 504             return self.unions[name]
 505         elif name in self.aliases:
 506             return self.aliases[name]
 507         elif mundane_name in self.types:
 508             return self.types[mundane_name]
 509         elif mundane_name in self.enums:
 510             return self.enums[mundane_name]
 511         elif mundane_name in self.enumflags:
 512             return self.enumflags[mundane_name]
 513         elif mundane_name in self.unions:
 514             return self.unions[mundane_name]
 515         elif mundane_name in self.aliases:
 516             return self.aliases[mundane_name]
 517         raise ParseError(
 518             "Could not find type, enum or union by magic name `%s' nor by "
 519             "mundane name `%s'" % (name, mundane_name)
 520         )
 521
 522     def is_reply(self, message):
 523         return message in self.replies
 524
 525     def is_event(self, message):
 526         return message in self.events
 527
 528     def is_stream(self, message):
 529         return message in self.streams
 530
 531     def has_stream_msg(self, message):
 532         return (
 533             message.name in self.services
 534             and "stream_msg" in self.services[message.name]
 535         )
 536
 537     def get_stream_msg(self, message):
 538         if not self.has_stream_msg(message):
 539             return None
 540         return self.messages[self.services[message.name]["stream_msg"]]
 541
 542     def get_reply(self, message):
 543         return self.messages[self.services[message]["reply"]]
 544
 545     def finalize_parsing(self):
 546         if len(self.messages) == 0:
 547             for e in self.exceptions:
 548                 self.logger.warning(e)
 549         for jn, j in self.messages_by_json.items():
 550             remove = []
 551             for n, m in j.items():
 552                 try:
 553                     if not m.is_reply and not m.is_event and not m.is_stream:
 554                         try:
 555                             m.reply = self.get_reply(n)
 556                             m.reply_is_stream = False
 557                             m.has_stream_msg = self.has_stream_msg(m)
 558                             if "stream" in self.services[m.name]:
 559                                 m.reply_is_stream = self.services[m.name]["stream"]
 560                             if m.has_stream_msg:
 561                                 m.stream_msg = self.get_stream_msg(m)
 562                             m.reply.request = m
 563                         except:
 564                             raise ParseError("Cannot find reply to message `%s'" % n)
 565                 except ParseError as e:
 566                     self.exceptions.append(e)
 567                     remove.append(n)
 568
 569             self.messages_by_json[jn] = {k: v for k, v in j.items() if k not in remove}