238 lines
6.3 KiB
Python
238 lines
6.3 KiB
Python
"""
|
|
Websockets client for micropython
|
|
|
|
Based very heavily on
|
|
https://github.com/aaugustin/websockets/blob/master/websockets/client.py
|
|
"""
|
|
|
|
#import usocket as socket
|
|
import ubinascii as binascii
|
|
import urandom as random
|
|
import ure as re
|
|
import ustruct as struct
|
|
import usocket as socket
|
|
from ucollections import namedtuple
|
|
|
|
# Opcodes
|
|
OP_CONT = const(0x0)
|
|
OP_TEXT = const(0x1)
|
|
OP_BYTES = const(0x2)
|
|
OP_CLOSE = const(0x8)
|
|
OP_PING = const(0x9)
|
|
OP_PONG = const(0xa)
|
|
|
|
# Close codes
|
|
CLOSE_OK = const(1000)
|
|
CLOSE_GOING_AWAY = const(1001)
|
|
CLOSE_PROTOCOL_ERROR = const(1002)
|
|
CLOSE_DATA_NOT_SUPPORTED = const(1003)
|
|
CLOSE_BAD_DATA = const(1007)
|
|
CLOSE_POLICY_VIOLATION = const(1008)
|
|
CLOSE_TOO_BIG = const(1009)
|
|
CLOSE_MISSING_EXTN = const(1010)
|
|
CLOSE_BAD_CONDITION = const(1011)
|
|
|
|
URL_RE = re.compile(r'ws://([A-Za-z0-9\-\.]+)(?:\:([0-9]+))?(/.+)?')
|
|
URI = namedtuple('URI', ('hostname', 'port', 'path'))
|
|
|
|
def urlparse(uri):
|
|
match = URL_RE.match(uri)
|
|
if match:
|
|
return URI(match.group(1), int(match.group(2)), match.group(3))
|
|
else:
|
|
raise ValueError("Invalid URL: %s" % uri)
|
|
|
|
class Websocket:
|
|
is_client = False
|
|
|
|
def __init__(self, sock):
|
|
self._sock = sock
|
|
self.open = True
|
|
|
|
def __enter__(self):
|
|
return self
|
|
|
|
def __exit__(self, exc_type, exc, tb):
|
|
self.close()
|
|
|
|
def settimeout(self, timeout):
|
|
self._sock.settimeout(timeout)
|
|
|
|
def read_frame(self, max_size=None):
|
|
|
|
# Frame header
|
|
byte1, byte2 = struct.unpack('!BB', self._sock.read(2))
|
|
|
|
# Byte 1: FIN(1) _(1) _(1) _(1) OPCODE(4)
|
|
fin = bool(byte1 & 0x80)
|
|
opcode = byte1 & 0x0f
|
|
|
|
# Byte 2: MASK(1) LENGTH(7)
|
|
mask = bool(byte2 & (1 << 7))
|
|
length = byte2 & 0x7f
|
|
|
|
if length == 126: # Magic number, length header is 2 bytes
|
|
length, = struct.unpack('!H', self._sock.read(2))
|
|
elif length == 127: # Magic number, length header is 8 bytes
|
|
length, = struct.unpack('!Q', self._sock.read(8))
|
|
|
|
if mask: # Mask is 4 bytes
|
|
mask_bits = self._sock.read(4)
|
|
|
|
try:
|
|
data = self._sock.read(length)
|
|
except MemoryError:
|
|
# We can't receive this many bytes, close the socket
|
|
self.close(code=CLOSE_TOO_BIG)
|
|
return True, OP_CLOSE, None
|
|
|
|
if mask:
|
|
data = bytes(b ^ mask_bits[i % 4]
|
|
for i, b in enumerate(data))
|
|
|
|
return fin, opcode, data
|
|
|
|
def write_frame(self, opcode, data=b''):
|
|
|
|
fin = True
|
|
mask = self.is_client # messages sent by client are masked
|
|
|
|
length = len(data)
|
|
|
|
# Frame header
|
|
# Byte 1: FIN(1) _(1) _(1) _(1) OPCODE(4)
|
|
byte1 = 0x80 if fin else 0
|
|
byte1 |= opcode
|
|
|
|
# Byte 2: MASK(1) LENGTH(7)
|
|
byte2 = 0x80 if mask else 0
|
|
|
|
if length < 126: # 126 is magic value to use 2-byte length header
|
|
byte2 |= length
|
|
self._sock.write(struct.pack('!BB', byte1, byte2))
|
|
|
|
elif length < (1 << 16): # Length fits in 2-bytes
|
|
byte2 |= 126 # Magic code
|
|
self._sock.write(struct.pack('!BBH', byte1, byte2, length))
|
|
|
|
elif length < (1 << 64):
|
|
byte2 |= 127 # Magic code
|
|
self._sock.write(struct.pack('!BBQ', byte1, byte2, length))
|
|
|
|
else:
|
|
raise ValueError()
|
|
|
|
if mask: # Mask is 4 bytes
|
|
mask_bits = struct.pack('!I', random.getrandbits(32))
|
|
self._sock.write(mask_bits)
|
|
|
|
data = bytes(b ^ mask_bits[i % 4]
|
|
for i, b in enumerate(data))
|
|
|
|
self._sock.write(data)
|
|
|
|
def recv(self):
|
|
assert self.open
|
|
|
|
while self.open:
|
|
try:
|
|
fin, opcode, data = self.read_frame()
|
|
except ValueError:
|
|
self._close()
|
|
return
|
|
|
|
if not fin:
|
|
raise NotImplementedError()
|
|
|
|
if opcode == OP_TEXT:
|
|
return data.decode('utf-8')
|
|
elif opcode == OP_BYTES:
|
|
return data
|
|
elif opcode == OP_CLOSE:
|
|
self._close()
|
|
return
|
|
elif opcode == OP_PONG:
|
|
# Ignore this frame, keep waiting for a data frame
|
|
continue
|
|
elif opcode == OP_PING:
|
|
# We need to send a pong frame
|
|
self.write_frame(OP_PONG, data)
|
|
# And then wait to receive
|
|
continue
|
|
elif opcode == OP_CONT:
|
|
# This is a continuation of a previous frame
|
|
raise NotImplementedError(opcode)
|
|
else:
|
|
raise ValueError(opcode)
|
|
|
|
def send(self, buf):
|
|
|
|
assert self.open
|
|
|
|
if isinstance(buf, str):
|
|
opcode = OP_TEXT
|
|
buf = buf.encode('utf-8')
|
|
elif isinstance(buf, bytes):
|
|
opcode = OP_BYTES
|
|
else:
|
|
raise TypeError()
|
|
|
|
self.write_frame(opcode, buf)
|
|
|
|
def close(self, code=CLOSE_OK, reason=''):
|
|
|
|
if not self.open:
|
|
return
|
|
|
|
buf = struct.pack('!H', code) + reason.encode('utf-8')
|
|
|
|
self.write_frame(OP_CLOSE, buf)
|
|
self._close()
|
|
|
|
def _close(self):
|
|
self.open = False
|
|
self._sock.close()
|
|
|
|
class WebsocketClient(Websocket):
|
|
is_client = True
|
|
|
|
|
|
def connect(uri):
|
|
"""
|
|
Connect a websocket.
|
|
"""
|
|
|
|
uri = urlparse(uri)
|
|
assert uri
|
|
|
|
sock = socket.socket()
|
|
addr = socket.getaddrinfo(uri.hostname, uri.port)
|
|
print(addr)
|
|
sock.connect(addr[0][4])
|
|
|
|
def send_header(header, *args):
|
|
sock.send(header % args + '\r\n')
|
|
|
|
# Sec-WebSocket-Key is 16 bytes of random base64 encoded
|
|
key = binascii.b2a_base64(bytes(random.getrandbits(8)
|
|
for _ in range(16)))[:-1]
|
|
|
|
send_header(b'GET %s HTTP/1.1', uri.path or '/')
|
|
send_header(b'Host: %s:%s', uri.hostname, uri.port)
|
|
send_header(b'Connection: Upgrade')
|
|
send_header(b'Upgrade: websocket')
|
|
send_header(b'Sec-WebSocket-Key: %s', key)
|
|
send_header(b'Sec-WebSocket-Version: 13')
|
|
send_header(b'Origin: http://localhost')
|
|
send_header(b'')
|
|
|
|
header = sock.readline()[:-2]
|
|
assert header == b'HTTP/1.1 101 Switching Protocols', header
|
|
|
|
# We don't (currently) need these headers
|
|
# FIXME: should we check the return key?
|
|
while header:
|
|
header = sock.readline()[:-2]
|
|
|
|
return WebsocketClient(sock)
|