You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
424 lines
13 KiB
424 lines
13 KiB
"""
|
|
|
|
"""
|
|
|
|
"""
|
|
_abnf.py
|
|
websocket - WebSocket client library for Python
|
|
|
|
Copyright 2021 engn33r
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
"""
|
|
import array
|
|
import os
|
|
import struct
|
|
import sys
|
|
|
|
from ._exceptions import *
|
|
from ._utils import validate_utf8
|
|
from threading import Lock
|
|
|
|
try:
|
|
# If wsaccel is available, use compiled routines to mask data.
|
|
# wsaccel only provides around a 10% speed boost compared
|
|
# to the websocket-client _mask() implementation.
|
|
# Note that wsaccel is unmaintained.
|
|
from wsaccel.xormask import XorMaskerSimple
|
|
|
|
def _mask(_m, _d):
|
|
return XorMaskerSimple(_m).process(_d)
|
|
|
|
except ImportError:
|
|
# wsaccel is not available, use websocket-client _mask()
|
|
native_byteorder = sys.byteorder
|
|
|
|
def _mask(mask_value, data_value):
|
|
datalen = len(data_value)
|
|
data_value = int.from_bytes(data_value, native_byteorder)
|
|
mask_value = int.from_bytes(mask_value * (datalen // 4) + mask_value[: datalen % 4], native_byteorder)
|
|
return (data_value ^ mask_value).to_bytes(datalen, native_byteorder)
|
|
|
|
|
|
__all__ = [
|
|
'ABNF', 'continuous_frame', 'frame_buffer',
|
|
'STATUS_NORMAL',
|
|
'STATUS_GOING_AWAY',
|
|
'STATUS_PROTOCOL_ERROR',
|
|
'STATUS_UNSUPPORTED_DATA_TYPE',
|
|
'STATUS_STATUS_NOT_AVAILABLE',
|
|
'STATUS_ABNORMAL_CLOSED',
|
|
'STATUS_INVALID_PAYLOAD',
|
|
'STATUS_POLICY_VIOLATION',
|
|
'STATUS_MESSAGE_TOO_BIG',
|
|
'STATUS_INVALID_EXTENSION',
|
|
'STATUS_UNEXPECTED_CONDITION',
|
|
'STATUS_BAD_GATEWAY',
|
|
'STATUS_TLS_HANDSHAKE_ERROR',
|
|
]
|
|
|
|
# closing frame status codes.
|
|
STATUS_NORMAL = 1000
|
|
STATUS_GOING_AWAY = 1001
|
|
STATUS_PROTOCOL_ERROR = 1002
|
|
STATUS_UNSUPPORTED_DATA_TYPE = 1003
|
|
STATUS_STATUS_NOT_AVAILABLE = 1005
|
|
STATUS_ABNORMAL_CLOSED = 1006
|
|
STATUS_INVALID_PAYLOAD = 1007
|
|
STATUS_POLICY_VIOLATION = 1008
|
|
STATUS_MESSAGE_TOO_BIG = 1009
|
|
STATUS_INVALID_EXTENSION = 1010
|
|
STATUS_UNEXPECTED_CONDITION = 1011
|
|
STATUS_BAD_GATEWAY = 1014
|
|
STATUS_TLS_HANDSHAKE_ERROR = 1015
|
|
|
|
VALID_CLOSE_STATUS = (
|
|
STATUS_NORMAL,
|
|
STATUS_GOING_AWAY,
|
|
STATUS_PROTOCOL_ERROR,
|
|
STATUS_UNSUPPORTED_DATA_TYPE,
|
|
STATUS_INVALID_PAYLOAD,
|
|
STATUS_POLICY_VIOLATION,
|
|
STATUS_MESSAGE_TOO_BIG,
|
|
STATUS_INVALID_EXTENSION,
|
|
STATUS_UNEXPECTED_CONDITION,
|
|
STATUS_BAD_GATEWAY,
|
|
)
|
|
|
|
|
|
class ABNF:
|
|
"""
|
|
ABNF frame class.
|
|
See http://tools.ietf.org/html/rfc5234
|
|
and http://tools.ietf.org/html/rfc6455#section-5.2
|
|
"""
|
|
|
|
# operation code values.
|
|
OPCODE_CONT = 0x0
|
|
OPCODE_TEXT = 0x1
|
|
OPCODE_BINARY = 0x2
|
|
OPCODE_CLOSE = 0x8
|
|
OPCODE_PING = 0x9
|
|
OPCODE_PONG = 0xa
|
|
|
|
# available operation code value tuple
|
|
OPCODES = (OPCODE_CONT, OPCODE_TEXT, OPCODE_BINARY, OPCODE_CLOSE,
|
|
OPCODE_PING, OPCODE_PONG)
|
|
|
|
# opcode human readable string
|
|
OPCODE_MAP = {
|
|
OPCODE_CONT: "cont",
|
|
OPCODE_TEXT: "text",
|
|
OPCODE_BINARY: "binary",
|
|
OPCODE_CLOSE: "close",
|
|
OPCODE_PING: "ping",
|
|
OPCODE_PONG: "pong"
|
|
}
|
|
|
|
# data length threshold.
|
|
LENGTH_7 = 0x7e
|
|
LENGTH_16 = 1 << 16
|
|
LENGTH_63 = 1 << 63
|
|
|
|
def __init__(self, fin=0, rsv1=0, rsv2=0, rsv3=0,
|
|
opcode=OPCODE_TEXT, mask=1, data=""):
|
|
"""
|
|
Constructor for ABNF. Please check RFC for arguments.
|
|
"""
|
|
self.fin = fin
|
|
self.rsv1 = rsv1
|
|
self.rsv2 = rsv2
|
|
self.rsv3 = rsv3
|
|
self.opcode = opcode
|
|
self.mask = mask
|
|
if data is None:
|
|
data = ""
|
|
self.data = data
|
|
self.get_mask_key = os.urandom
|
|
|
|
def validate(self, skip_utf8_validation=False):
|
|
"""
|
|
Validate the ABNF frame.
|
|
|
|
Parameters
|
|
----------
|
|
skip_utf8_validation: skip utf8 validation.
|
|
"""
|
|
if self.rsv1 or self.rsv2 or self.rsv3:
|
|
raise WebSocketProtocolException("rsv is not implemented, yet")
|
|
|
|
if self.opcode not in ABNF.OPCODES:
|
|
raise WebSocketProtocolException("Invalid opcode %r", self.opcode)
|
|
|
|
if self.opcode == ABNF.OPCODE_PING and not self.fin:
|
|
raise WebSocketProtocolException("Invalid ping frame.")
|
|
|
|
if self.opcode == ABNF.OPCODE_CLOSE:
|
|
l = len(self.data)
|
|
if not l:
|
|
return
|
|
if l == 1 or l >= 126:
|
|
raise WebSocketProtocolException("Invalid close frame.")
|
|
if l > 2 and not skip_utf8_validation and not validate_utf8(self.data[2:]):
|
|
raise WebSocketProtocolException("Invalid close frame.")
|
|
|
|
code = 256 * self.data[0] + self.data[1]
|
|
if not self._is_valid_close_status(code):
|
|
raise WebSocketProtocolException("Invalid close opcode.")
|
|
|
|
@staticmethod
|
|
def _is_valid_close_status(code):
|
|
return code in VALID_CLOSE_STATUS or (3000 <= code < 5000)
|
|
|
|
def __str__(self):
|
|
return "fin=" + str(self.fin) \
|
|
+ " opcode=" + str(self.opcode) \
|
|
+ " data=" + str(self.data)
|
|
|
|
@staticmethod
|
|
def create_frame(data, opcode, fin=1):
|
|
"""
|
|
Create frame to send text, binary and other data.
|
|
|
|
Parameters
|
|
----------
|
|
data: <type>
|
|
data to send. This is string value(byte array).
|
|
If opcode is OPCODE_TEXT and this value is unicode,
|
|
data value is converted into unicode string, automatically.
|
|
opcode: <type>
|
|
operation code. please see OPCODE_XXX.
|
|
fin: <type>
|
|
fin flag. if set to 0, create continue fragmentation.
|
|
"""
|
|
if opcode == ABNF.OPCODE_TEXT and isinstance(data, str):
|
|
data = data.encode("utf-8")
|
|
# mask must be set if send data from client
|
|
return ABNF(fin, 0, 0, 0, opcode, 1, data)
|
|
|
|
def format(self):
|
|
"""
|
|
Format this object to string(byte array) to send data to server.
|
|
"""
|
|
if any(x not in (0, 1) for x in [self.fin, self.rsv1, self.rsv2, self.rsv3]):
|
|
raise ValueError("not 0 or 1")
|
|
if self.opcode not in ABNF.OPCODES:
|
|
raise ValueError("Invalid OPCODE")
|
|
length = len(self.data)
|
|
if length >= ABNF.LENGTH_63:
|
|
raise ValueError("data is too long")
|
|
|
|
frame_header = chr(self.fin << 7 |
|
|
self.rsv1 << 6 | self.rsv2 << 5 | self.rsv3 << 4 |
|
|
self.opcode).encode('latin-1')
|
|
if length < ABNF.LENGTH_7:
|
|
frame_header += chr(self.mask << 7 | length).encode('latin-1')
|
|
elif length < ABNF.LENGTH_16:
|
|
frame_header += chr(self.mask << 7 | 0x7e).encode('latin-1')
|
|
frame_header += struct.pack("!H", length)
|
|
else:
|
|
frame_header += chr(self.mask << 7 | 0x7f).encode('latin-1')
|
|
frame_header += struct.pack("!Q", length)
|
|
|
|
if not self.mask:
|
|
return frame_header + self.data
|
|
else:
|
|
mask_key = self.get_mask_key(4)
|
|
return frame_header + self._get_masked(mask_key)
|
|
|
|
def _get_masked(self, mask_key):
|
|
s = ABNF.mask(mask_key, self.data)
|
|
|
|
if isinstance(mask_key, str):
|
|
mask_key = mask_key.encode('utf-8')
|
|
|
|
return mask_key + s
|
|
|
|
@staticmethod
|
|
def mask(mask_key, data):
|
|
"""
|
|
Mask or unmask data. Just do xor for each byte
|
|
|
|
Parameters
|
|
----------
|
|
mask_key: <type>
|
|
4 byte string.
|
|
data: <type>
|
|
data to mask/unmask.
|
|
"""
|
|
if data is None:
|
|
data = ""
|
|
|
|
if isinstance(mask_key, str):
|
|
mask_key = mask_key.encode('latin-1')
|
|
|
|
if isinstance(data, str):
|
|
data = data.encode('latin-1')
|
|
|
|
return _mask(array.array("B", mask_key), array.array("B", data))
|
|
|
|
|
|
class frame_buffer:
|
|
_HEADER_MASK_INDEX = 5
|
|
_HEADER_LENGTH_INDEX = 6
|
|
|
|
def __init__(self, recv_fn, skip_utf8_validation):
|
|
self.recv = recv_fn
|
|
self.skip_utf8_validation = skip_utf8_validation
|
|
# Buffers over the packets from the layer beneath until desired amount
|
|
# bytes of bytes are received.
|
|
self.recv_buffer = []
|
|
self.clear()
|
|
self.lock = Lock()
|
|
|
|
def clear(self):
|
|
self.header = None
|
|
self.length = None
|
|
self.mask = None
|
|
|
|
def has_received_header(self):
|
|
return self.header is None
|
|
|
|
def recv_header(self):
|
|
header = self.recv_strict(2)
|
|
b1 = header[0]
|
|
fin = b1 >> 7 & 1
|
|
rsv1 = b1 >> 6 & 1
|
|
rsv2 = b1 >> 5 & 1
|
|
rsv3 = b1 >> 4 & 1
|
|
opcode = b1 & 0xf
|
|
b2 = header[1]
|
|
has_mask = b2 >> 7 & 1
|
|
length_bits = b2 & 0x7f
|
|
|
|
self.header = (fin, rsv1, rsv2, rsv3, opcode, has_mask, length_bits)
|
|
|
|
def has_mask(self):
|
|
if not self.header:
|
|
return False
|
|
return self.header[frame_buffer._HEADER_MASK_INDEX]
|
|
|
|
def has_received_length(self):
|
|
return self.length is None
|
|
|
|
def recv_length(self):
|
|
bits = self.header[frame_buffer._HEADER_LENGTH_INDEX]
|
|
length_bits = bits & 0x7f
|
|
if length_bits == 0x7e:
|
|
v = self.recv_strict(2)
|
|
self.length = struct.unpack("!H", v)[0]
|
|
elif length_bits == 0x7f:
|
|
v = self.recv_strict(8)
|
|
self.length = struct.unpack("!Q", v)[0]
|
|
else:
|
|
self.length = length_bits
|
|
|
|
def has_received_mask(self):
|
|
return self.mask is None
|
|
|
|
def recv_mask(self):
|
|
self.mask = self.recv_strict(4) if self.has_mask() else ""
|
|
|
|
def recv_frame(self):
|
|
|
|
with self.lock:
|
|
# Header
|
|
if self.has_received_header():
|
|
self.recv_header()
|
|
(fin, rsv1, rsv2, rsv3, opcode, has_mask, _) = self.header
|
|
|
|
# Frame length
|
|
if self.has_received_length():
|
|
self.recv_length()
|
|
length = self.length
|
|
|
|
# Mask
|
|
if self.has_received_mask():
|
|
self.recv_mask()
|
|
mask = self.mask
|
|
|
|
# Payload
|
|
payload = self.recv_strict(length)
|
|
if has_mask:
|
|
payload = ABNF.mask(mask, payload)
|
|
|
|
# Reset for next frame
|
|
self.clear()
|
|
|
|
frame = ABNF(fin, rsv1, rsv2, rsv3, opcode, has_mask, payload)
|
|
frame.validate(self.skip_utf8_validation)
|
|
|
|
return frame
|
|
|
|
def recv_strict(self, bufsize):
|
|
shortage = bufsize - sum(map(len, self.recv_buffer))
|
|
while shortage > 0:
|
|
# Limit buffer size that we pass to socket.recv() to avoid
|
|
# fragmenting the heap -- the number of bytes recv() actually
|
|
# reads is limited by socket buffer and is relatively small,
|
|
# yet passing large numbers repeatedly causes lots of large
|
|
# buffers allocated and then shrunk, which results in
|
|
# fragmentation.
|
|
bytes_ = self.recv(min(16384, shortage))
|
|
self.recv_buffer.append(bytes_)
|
|
shortage -= len(bytes_)
|
|
|
|
unified = b"".join(self.recv_buffer)
|
|
|
|
if shortage == 0:
|
|
self.recv_buffer = []
|
|
return unified
|
|
else:
|
|
self.recv_buffer = [unified[bufsize:]]
|
|
return unified[:bufsize]
|
|
|
|
|
|
class continuous_frame:
|
|
|
|
def __init__(self, fire_cont_frame, skip_utf8_validation):
|
|
self.fire_cont_frame = fire_cont_frame
|
|
self.skip_utf8_validation = skip_utf8_validation
|
|
self.cont_data = None
|
|
self.recving_frames = None
|
|
|
|
def validate(self, frame):
|
|
if not self.recving_frames and frame.opcode == ABNF.OPCODE_CONT:
|
|
raise WebSocketProtocolException("Illegal frame")
|
|
if self.recving_frames and \
|
|
frame.opcode in (ABNF.OPCODE_TEXT, ABNF.OPCODE_BINARY):
|
|
raise WebSocketProtocolException("Illegal frame")
|
|
|
|
def add(self, frame):
|
|
if self.cont_data:
|
|
self.cont_data[1] += frame.data
|
|
else:
|
|
if frame.opcode in (ABNF.OPCODE_TEXT, ABNF.OPCODE_BINARY):
|
|
self.recving_frames = frame.opcode
|
|
self.cont_data = [frame.opcode, frame.data]
|
|
|
|
if frame.fin:
|
|
self.recving_frames = None
|
|
|
|
def is_fire(self, frame):
|
|
return frame.fin or self.fire_cont_frame
|
|
|
|
def extract(self, frame):
|
|
data = self.cont_data
|
|
self.cont_data = None
|
|
frame.data = data[1]
|
|
if not self.fire_cont_frame and data[0] == ABNF.OPCODE_TEXT and not self.skip_utf8_validation and not validate_utf8(frame.data):
|
|
raise WebSocketPayloadException(
|
|
"cannot decode: " + repr(frame.data))
|
|
|
|
return [data[0], frame]
|