File size: 18,791 Bytes
9c6594c |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 |
"""Reader for WebSocket protocol versions 13 and 8."""
import asyncio
import builtins
from collections import deque
from typing import Deque, Final, Optional, Set, Tuple, Union
from ..base_protocol import BaseProtocol
from ..compression_utils import ZLibDecompressor
from ..helpers import _EXC_SENTINEL, set_exception
from ..streams import EofStream
from .helpers import UNPACK_CLOSE_CODE, UNPACK_LEN3, websocket_mask
from .models import (
WS_DEFLATE_TRAILING,
WebSocketError,
WSCloseCode,
WSMessage,
WSMsgType,
)
ALLOWED_CLOSE_CODES: Final[Set[int]] = {int(i) for i in WSCloseCode}
# States for the reader, used to parse the WebSocket frame
# integer values are used so they can be cythonized
READ_HEADER = 1
READ_PAYLOAD_LENGTH = 2
READ_PAYLOAD_MASK = 3
READ_PAYLOAD = 4
WS_MSG_TYPE_BINARY = WSMsgType.BINARY
WS_MSG_TYPE_TEXT = WSMsgType.TEXT
# WSMsgType values unpacked so they can by cythonized to ints
OP_CODE_NOT_SET = -1
OP_CODE_CONTINUATION = WSMsgType.CONTINUATION.value
OP_CODE_TEXT = WSMsgType.TEXT.value
OP_CODE_BINARY = WSMsgType.BINARY.value
OP_CODE_CLOSE = WSMsgType.CLOSE.value
OP_CODE_PING = WSMsgType.PING.value
OP_CODE_PONG = WSMsgType.PONG.value
EMPTY_FRAME_ERROR = (True, b"")
EMPTY_FRAME = (False, b"")
COMPRESSED_NOT_SET = -1
COMPRESSED_FALSE = 0
COMPRESSED_TRUE = 1
TUPLE_NEW = tuple.__new__
cython_int = int # Typed to int in Python, but cython with use a signed int in the pxd
class WebSocketDataQueue:
"""WebSocketDataQueue resumes and pauses an underlying stream.
It is a destination for WebSocket data.
"""
def __init__(
self, protocol: BaseProtocol, limit: int, *, loop: asyncio.AbstractEventLoop
) -> None:
self._size = 0
self._protocol = protocol
self._limit = limit * 2
self._loop = loop
self._eof = False
self._waiter: Optional[asyncio.Future[None]] = None
self._exception: Union[BaseException, None] = None
self._buffer: Deque[Tuple[WSMessage, int]] = deque()
self._get_buffer = self._buffer.popleft
self._put_buffer = self._buffer.append
def is_eof(self) -> bool:
return self._eof
def exception(self) -> Optional[BaseException]:
return self._exception
def set_exception(
self,
exc: BaseException,
exc_cause: builtins.BaseException = _EXC_SENTINEL,
) -> None:
self._eof = True
self._exception = exc
if (waiter := self._waiter) is not None:
self._waiter = None
set_exception(waiter, exc, exc_cause)
def _release_waiter(self) -> None:
if (waiter := self._waiter) is None:
return
self._waiter = None
if not waiter.done():
waiter.set_result(None)
def feed_eof(self) -> None:
self._eof = True
self._release_waiter()
self._exception = None # Break cyclic references
def feed_data(self, data: "WSMessage", size: "cython_int") -> None:
self._size += size
self._put_buffer((data, size))
self._release_waiter()
if self._size > self._limit and not self._protocol._reading_paused:
self._protocol.pause_reading()
async def read(self) -> WSMessage:
if not self._buffer and not self._eof:
assert not self._waiter
self._waiter = self._loop.create_future()
try:
await self._waiter
except (asyncio.CancelledError, asyncio.TimeoutError):
self._waiter = None
raise
return self._read_from_buffer()
def _read_from_buffer(self) -> WSMessage:
if self._buffer:
data, size = self._get_buffer()
self._size -= size
if self._size < self._limit and self._protocol._reading_paused:
self._protocol.resume_reading()
return data
if self._exception is not None:
raise self._exception
raise EofStream
class WebSocketReader:
def __init__(
self, queue: WebSocketDataQueue, max_msg_size: int, compress: bool = True
) -> None:
self.queue = queue
self._max_msg_size = max_msg_size
self._exc: Optional[Exception] = None
self._partial = bytearray()
self._state = READ_HEADER
self._opcode: int = OP_CODE_NOT_SET
self._frame_fin = False
self._frame_opcode: int = OP_CODE_NOT_SET
self._payload_fragments: list[bytes] = []
self._frame_payload_len = 0
self._tail: bytes = b""
self._has_mask = False
self._frame_mask: Optional[bytes] = None
self._payload_bytes_to_read = 0
self._payload_len_flag = 0
self._compressed: int = COMPRESSED_NOT_SET
self._decompressobj: Optional[ZLibDecompressor] = None
self._compress = compress
def feed_eof(self) -> None:
self.queue.feed_eof()
# data can be bytearray on Windows because proactor event loop uses bytearray
# and asyncio types this to Union[bytes, bytearray, memoryview] so we need
# coerce data to bytes if it is not
def feed_data(
self, data: Union[bytes, bytearray, memoryview]
) -> Tuple[bool, bytes]:
if type(data) is not bytes:
data = bytes(data)
if self._exc is not None:
return True, data
try:
self._feed_data(data)
except Exception as exc:
self._exc = exc
set_exception(self.queue, exc)
return EMPTY_FRAME_ERROR
return EMPTY_FRAME
def _handle_frame(
self,
fin: bool,
opcode: Union[int, cython_int], # Union intended: Cython pxd uses C int
payload: Union[bytes, bytearray],
compressed: Union[int, cython_int], # Union intended: Cython pxd uses C int
) -> None:
msg: WSMessage
if opcode in {OP_CODE_TEXT, OP_CODE_BINARY, OP_CODE_CONTINUATION}:
# load text/binary
if not fin:
# got partial frame payload
if opcode != OP_CODE_CONTINUATION:
self._opcode = opcode
self._partial += payload
if self._max_msg_size and len(self._partial) >= self._max_msg_size:
raise WebSocketError(
WSCloseCode.MESSAGE_TOO_BIG,
f"Message size {len(self._partial)} "
f"exceeds limit {self._max_msg_size}",
)
return
has_partial = bool(self._partial)
if opcode == OP_CODE_CONTINUATION:
if self._opcode == OP_CODE_NOT_SET:
raise WebSocketError(
WSCloseCode.PROTOCOL_ERROR,
"Continuation frame for non started message",
)
opcode = self._opcode
self._opcode = OP_CODE_NOT_SET
# previous frame was non finished
# we should get continuation opcode
elif has_partial:
raise WebSocketError(
WSCloseCode.PROTOCOL_ERROR,
"The opcode in non-fin frame is expected "
f"to be zero, got {opcode!r}",
)
assembled_payload: Union[bytes, bytearray]
if has_partial:
assembled_payload = self._partial + payload
self._partial.clear()
else:
assembled_payload = payload
if self._max_msg_size and len(assembled_payload) >= self._max_msg_size:
raise WebSocketError(
WSCloseCode.MESSAGE_TOO_BIG,
f"Message size {len(assembled_payload)} "
f"exceeds limit {self._max_msg_size}",
)
# Decompress process must to be done after all packets
# received.
if compressed:
if not self._decompressobj:
self._decompressobj = ZLibDecompressor(suppress_deflate_header=True)
# XXX: It's possible that the zlib backend (isal is known to
# do this, maybe others too?) will return max_length bytes,
# but internally buffer more data such that the payload is
# >max_length, so we return one extra byte and if we're able
# to do that, then the message is too big.
payload_merged = self._decompressobj.decompress_sync(
assembled_payload + WS_DEFLATE_TRAILING,
(
self._max_msg_size + 1
if self._max_msg_size
else self._max_msg_size
),
)
if self._max_msg_size and len(payload_merged) > self._max_msg_size:
raise WebSocketError(
WSCloseCode.MESSAGE_TOO_BIG,
f"Decompressed message exceeds size limit {self._max_msg_size}",
)
elif type(assembled_payload) is bytes:
payload_merged = assembled_payload
else:
payload_merged = bytes(assembled_payload)
if opcode == OP_CODE_TEXT:
try:
text = payload_merged.decode("utf-8")
except UnicodeDecodeError as exc:
raise WebSocketError(
WSCloseCode.INVALID_TEXT, "Invalid UTF-8 text message"
) from exc
# XXX: The Text and Binary messages here can be a performance
# bottleneck, so we use tuple.__new__ to improve performance.
# This is not type safe, but many tests should fail in
# test_client_ws_functional.py if this is wrong.
self.queue.feed_data(
TUPLE_NEW(WSMessage, (WS_MSG_TYPE_TEXT, text, "")),
len(payload_merged),
)
else:
self.queue.feed_data(
TUPLE_NEW(WSMessage, (WS_MSG_TYPE_BINARY, payload_merged, "")),
len(payload_merged),
)
elif opcode == OP_CODE_CLOSE:
if len(payload) >= 2:
close_code = UNPACK_CLOSE_CODE(payload[:2])[0]
if close_code < 3000 and close_code not in ALLOWED_CLOSE_CODES:
raise WebSocketError(
WSCloseCode.PROTOCOL_ERROR,
f"Invalid close code: {close_code}",
)
try:
close_message = payload[2:].decode("utf-8")
except UnicodeDecodeError as exc:
raise WebSocketError(
WSCloseCode.INVALID_TEXT, "Invalid UTF-8 text message"
) from exc
msg = TUPLE_NEW(WSMessage, (WSMsgType.CLOSE, close_code, close_message))
elif payload:
raise WebSocketError(
WSCloseCode.PROTOCOL_ERROR,
f"Invalid close frame: {fin} {opcode} {payload!r}",
)
else:
msg = TUPLE_NEW(WSMessage, (WSMsgType.CLOSE, 0, ""))
self.queue.feed_data(msg, 0)
elif opcode == OP_CODE_PING:
msg = TUPLE_NEW(WSMessage, (WSMsgType.PING, payload, ""))
self.queue.feed_data(msg, len(payload))
elif opcode == OP_CODE_PONG:
msg = TUPLE_NEW(WSMessage, (WSMsgType.PONG, payload, ""))
self.queue.feed_data(msg, len(payload))
else:
raise WebSocketError(
WSCloseCode.PROTOCOL_ERROR, f"Unexpected opcode={opcode!r}"
)
def _feed_data(self, data: bytes) -> None:
"""Return the next frame from the socket."""
if self._tail:
data, self._tail = self._tail + data, b""
start_pos: int = 0
data_len = len(data)
data_cstr = data
while True:
# read header
if self._state == READ_HEADER:
if data_len - start_pos < 2:
break
first_byte = data_cstr[start_pos]
second_byte = data_cstr[start_pos + 1]
start_pos += 2
fin = (first_byte >> 7) & 1
rsv1 = (first_byte >> 6) & 1
rsv2 = (first_byte >> 5) & 1
rsv3 = (first_byte >> 4) & 1
opcode = first_byte & 0xF
# frame-fin = %x0 ; more frames of this message follow
# / %x1 ; final frame of this message
# frame-rsv1 = %x0 ;
# 1 bit, MUST be 0 unless negotiated otherwise
# frame-rsv2 = %x0 ;
# 1 bit, MUST be 0 unless negotiated otherwise
# frame-rsv3 = %x0 ;
# 1 bit, MUST be 0 unless negotiated otherwise
#
# Remove rsv1 from this test for deflate development
if rsv2 or rsv3 or (rsv1 and not self._compress):
raise WebSocketError(
WSCloseCode.PROTOCOL_ERROR,
"Received frame with non-zero reserved bits",
)
if opcode > 0x7 and fin == 0:
raise WebSocketError(
WSCloseCode.PROTOCOL_ERROR,
"Received fragmented control frame",
)
has_mask = (second_byte >> 7) & 1
length = second_byte & 0x7F
# Control frames MUST have a payload
# length of 125 bytes or less
if opcode > 0x7 and length > 125:
raise WebSocketError(
WSCloseCode.PROTOCOL_ERROR,
"Control frame payload cannot be larger than 125 bytes",
)
# Set compress status if last package is FIN
# OR set compress status if this is first fragment
# Raise error if not first fragment with rsv1 = 0x1
if self._frame_fin or self._compressed == COMPRESSED_NOT_SET:
self._compressed = COMPRESSED_TRUE if rsv1 else COMPRESSED_FALSE
elif rsv1:
raise WebSocketError(
WSCloseCode.PROTOCOL_ERROR,
"Received frame with non-zero reserved bits",
)
self._frame_fin = bool(fin)
self._frame_opcode = opcode
self._has_mask = bool(has_mask)
self._payload_len_flag = length
self._state = READ_PAYLOAD_LENGTH
# read payload length
if self._state == READ_PAYLOAD_LENGTH:
len_flag = self._payload_len_flag
if len_flag == 126:
if data_len - start_pos < 2:
break
first_byte = data_cstr[start_pos]
second_byte = data_cstr[start_pos + 1]
start_pos += 2
self._payload_bytes_to_read = first_byte << 8 | second_byte
elif len_flag > 126:
if data_len - start_pos < 8:
break
self._payload_bytes_to_read = UNPACK_LEN3(data, start_pos)[0]
start_pos += 8
else:
self._payload_bytes_to_read = len_flag
self._state = READ_PAYLOAD_MASK if self._has_mask else READ_PAYLOAD
# read payload mask
if self._state == READ_PAYLOAD_MASK:
if data_len - start_pos < 4:
break
self._frame_mask = data_cstr[start_pos : start_pos + 4]
start_pos += 4
self._state = READ_PAYLOAD
if self._state == READ_PAYLOAD:
chunk_len = data_len - start_pos
if self._payload_bytes_to_read >= chunk_len:
f_end_pos = data_len
self._payload_bytes_to_read -= chunk_len
else:
f_end_pos = start_pos + self._payload_bytes_to_read
self._payload_bytes_to_read = 0
had_fragments = self._frame_payload_len
self._frame_payload_len += f_end_pos - start_pos
f_start_pos = start_pos
start_pos = f_end_pos
if self._payload_bytes_to_read != 0:
# If we don't have a complete frame, we need to save the
# data for the next call to feed_data.
self._payload_fragments.append(data_cstr[f_start_pos:f_end_pos])
break
payload: Union[bytes, bytearray]
if had_fragments:
# We have to join the payload fragments get the payload
self._payload_fragments.append(data_cstr[f_start_pos:f_end_pos])
if self._has_mask:
assert self._frame_mask is not None
payload_bytearray = bytearray(b"".join(self._payload_fragments))
websocket_mask(self._frame_mask, payload_bytearray)
payload = payload_bytearray
else:
payload = b"".join(self._payload_fragments)
self._payload_fragments.clear()
elif self._has_mask:
assert self._frame_mask is not None
payload_bytearray = data_cstr[f_start_pos:f_end_pos] # type: ignore[assignment]
if type(payload_bytearray) is not bytearray: # pragma: no branch
# Cython will do the conversion for us
# but we need to do it for Python and we
# will always get here in Python
payload_bytearray = bytearray(payload_bytearray)
websocket_mask(self._frame_mask, payload_bytearray)
payload = payload_bytearray
else:
payload = data_cstr[f_start_pos:f_end_pos]
self._handle_frame(
self._frame_fin, self._frame_opcode, payload, self._compressed
)
self._frame_payload_len = 0
self._state = READ_HEADER
# XXX: Cython needs slices to be bounded, so we can't omit the slice end here.
self._tail = data_cstr[start_pos:data_len] if start_pos < data_len else b""
|