forked from protonphoton/LJ
372 lines
12 KiB
Python
372 lines
12 KiB
Python
# Author: Johan Hanssen Seferidis
|
|
# License: MIT
|
|
|
|
import sys
|
|
import struct
|
|
from base64 import b64encode
|
|
from hashlib import sha1
|
|
import logging
|
|
from socket import error as SocketError
|
|
import errno
|
|
|
|
if sys.version_info[0] < 3:
|
|
from SocketServer import ThreadingMixIn, TCPServer, StreamRequestHandler
|
|
else:
|
|
from socketserver import ThreadingMixIn, TCPServer, StreamRequestHandler
|
|
|
|
logger = logging.getLogger(__name__)
|
|
logging.basicConfig()
|
|
|
|
'''
|
|
+-+-+-+-+-------+-+-------------+-------------------------------+
|
|
0 1 2 3
|
|
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
|
|
+-+-+-+-+-------+-+-------------+-------------------------------+
|
|
|F|R|R|R| opcode|M| Payload len | Extended payload length |
|
|
|I|S|S|S| (4) |A| (7) | (16/64) |
|
|
|N|V|V|V| |S| | (if payload len==126/127) |
|
|
| |1|2|3| |K| | |
|
|
+-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +
|
|
| Extended payload length continued, if payload len == 127 |
|
|
+ - - - - - - - - - - - - - - - +-------------------------------+
|
|
| Payload Data continued ... |
|
|
+---------------------------------------------------------------+
|
|
'''
|
|
|
|
FIN = 0x80
|
|
OPCODE = 0x0f
|
|
MASKED = 0x80
|
|
PAYLOAD_LEN = 0x7f
|
|
PAYLOAD_LEN_EXT16 = 0x7e
|
|
PAYLOAD_LEN_EXT64 = 0x7f
|
|
|
|
OPCODE_CONTINUATION = 0x0
|
|
OPCODE_TEXT = 0x1
|
|
OPCODE_BINARY = 0x2
|
|
OPCODE_CLOSE_CONN = 0x8
|
|
OPCODE_PING = 0x9
|
|
OPCODE_PONG = 0xA
|
|
|
|
|
|
# -------------------------------- API ---------------------------------
|
|
|
|
class API():
|
|
|
|
def run_forever(self):
|
|
try:
|
|
logger.info("Listening on port %d for clients.." % self.port)
|
|
self.serve_forever()
|
|
except KeyboardInterrupt:
|
|
self.server_close()
|
|
logger.info("Server terminated.")
|
|
except Exception as e:
|
|
logger.error(str(e), exc_info=True)
|
|
exit(1)
|
|
|
|
def new_client(self, client, server):
|
|
pass
|
|
|
|
def client_left(self, client, server):
|
|
pass
|
|
|
|
def message_received(self, client, server, message):
|
|
pass
|
|
|
|
def set_fn_new_client(self, fn):
|
|
self.new_client = fn
|
|
|
|
def set_fn_client_left(self, fn):
|
|
self.client_left = fn
|
|
|
|
def set_fn_message_received(self, fn):
|
|
self.message_received = fn
|
|
|
|
def send_message(self, client, msg):
|
|
self._unicast_(client, msg)
|
|
|
|
def send_message_to_all(self, msg):
|
|
self._multicast_(msg)
|
|
|
|
|
|
# ------------------------- Implementation -----------------------------
|
|
|
|
class WebsocketServer(ThreadingMixIn, TCPServer, API):
|
|
"""
|
|
A websocket server waiting for clients to connect.
|
|
|
|
Args:
|
|
port(int): Port to bind to
|
|
host(str): Hostname or IP to listen for connections. By default 127.0.0.1
|
|
is being used. To accept connections from any client, you should use
|
|
0.0.0.0.
|
|
loglevel: Logging level from logging module to use for logging. By default
|
|
warnings and errors are being logged.
|
|
|
|
Properties:
|
|
clients(list): A list of connected clients. A client is a dictionary
|
|
like below.
|
|
{
|
|
'id' : id,
|
|
'handler' : handler,
|
|
'address' : (addr, port)
|
|
}
|
|
"""
|
|
|
|
allow_reuse_address = True
|
|
daemon_threads = True # comment to keep threads alive until finished
|
|
|
|
clients = []
|
|
id_counter = 0
|
|
|
|
def __init__(self, port, host='127.0.0.1', loglevel=logging.WARNING):
|
|
logger.setLevel(loglevel)
|
|
TCPServer.__init__(self, (host, port), WebSocketHandler)
|
|
self.port = self.socket.getsockname()[1]
|
|
|
|
def _message_received_(self, handler, msg):
|
|
self.message_received(self.handler_to_client(handler), self, msg)
|
|
|
|
def _ping_received_(self, handler, msg):
|
|
handler.send_pong(msg)
|
|
|
|
def _pong_received_(self, handler, msg):
|
|
pass
|
|
|
|
def _new_client_(self, handler):
|
|
self.id_counter += 1
|
|
client = {
|
|
'id': self.id_counter,
|
|
'handler': handler,
|
|
'address': handler.client_address
|
|
}
|
|
self.clients.append(client)
|
|
self.new_client(client, self)
|
|
|
|
def _client_left_(self, handler):
|
|
client = self.handler_to_client(handler)
|
|
self.client_left(client, self)
|
|
if client in self.clients:
|
|
self.clients.remove(client)
|
|
|
|
def _unicast_(self, to_client, msg):
|
|
to_client['handler'].send_message(msg)
|
|
|
|
def _multicast_(self, msg):
|
|
for client in self.clients:
|
|
self._unicast_(client, msg)
|
|
|
|
def handler_to_client(self, handler):
|
|
for client in self.clients:
|
|
if client['handler'] == handler:
|
|
return client
|
|
|
|
|
|
class WebSocketHandler(StreamRequestHandler):
|
|
|
|
def __init__(self, socket, addr, server):
|
|
self.server = server
|
|
StreamRequestHandler.__init__(self, socket, addr, server)
|
|
|
|
def setup(self):
|
|
StreamRequestHandler.setup(self)
|
|
self.keep_alive = True
|
|
self.handshake_done = False
|
|
self.valid_client = False
|
|
|
|
def handle(self):
|
|
while self.keep_alive:
|
|
if not self.handshake_done:
|
|
self.handshake()
|
|
elif self.valid_client:
|
|
self.read_next_message()
|
|
|
|
def read_bytes(self, num):
|
|
# python3 gives ordinal of byte directly
|
|
bytes = self.rfile.read(num)
|
|
if sys.version_info[0] < 3:
|
|
return map(ord, bytes)
|
|
else:
|
|
return bytes
|
|
|
|
def read_next_message(self):
|
|
try:
|
|
b1, b2 = self.read_bytes(2)
|
|
except SocketError as e: # to be replaced with ConnectionResetError for py3
|
|
if e.errno == errno.ECONNRESET:
|
|
logger.info("Client closed connection.")
|
|
print("Error: {}".format(e))
|
|
self.keep_alive = 0
|
|
return
|
|
b1, b2 = 0, 0
|
|
except ValueError as e:
|
|
b1, b2 = 0, 0
|
|
|
|
fin = b1 & FIN
|
|
opcode = b1 & OPCODE
|
|
masked = b2 & MASKED
|
|
payload_length = b2 & PAYLOAD_LEN
|
|
|
|
if opcode == OPCODE_CLOSE_CONN:
|
|
logger.info("Client asked to close connection.")
|
|
self.keep_alive = 0
|
|
return
|
|
if not masked:
|
|
logger.warn("Client must always be masked.")
|
|
self.keep_alive = 0
|
|
return
|
|
if opcode == OPCODE_CONTINUATION:
|
|
logger.warn("Continuation frames are not supported.")
|
|
return
|
|
elif opcode == OPCODE_BINARY:
|
|
logger.warn("Binary frames are not supported.")
|
|
return
|
|
elif opcode == OPCODE_TEXT:
|
|
opcode_handler = self.server._message_received_
|
|
elif opcode == OPCODE_PING:
|
|
opcode_handler = self.server._ping_received_
|
|
elif opcode == OPCODE_PONG:
|
|
opcode_handler = self.server._pong_received_
|
|
else:
|
|
logger.warn("Unknown opcode %#x." % opcode)
|
|
self.keep_alive = 0
|
|
return
|
|
|
|
if payload_length == 126:
|
|
payload_length = struct.unpack(">H", self.rfile.read(2))[0]
|
|
elif payload_length == 127:
|
|
payload_length = struct.unpack(">Q", self.rfile.read(8))[0]
|
|
|
|
masks = self.read_bytes(4)
|
|
message_bytes = bytearray()
|
|
for message_byte in self.read_bytes(payload_length):
|
|
message_byte ^= masks[len(message_bytes) % 4]
|
|
message_bytes.append(message_byte)
|
|
opcode_handler(self, message_bytes.decode('utf8'))
|
|
|
|
def send_message(self, message):
|
|
self.send_text(message)
|
|
|
|
def send_pong(self, message):
|
|
self.send_text(message, OPCODE_PONG)
|
|
|
|
def send_text(self, message, opcode=OPCODE_TEXT):
|
|
"""
|
|
Important: Fragmented(=continuation) messages are not supported since
|
|
their usage cases are limited - when we don't know the payload length.
|
|
"""
|
|
|
|
# Validate message
|
|
if isinstance(message, bytes):
|
|
message = try_decode_UTF8(message) # this is slower but ensures we have UTF-8
|
|
if not message:
|
|
logger.warning("Can\'t send message, message is not valid UTF-8")
|
|
return False
|
|
elif sys.version_info < (3,0) and (isinstance(message, str) or isinstance(message, unicode)):
|
|
pass
|
|
elif isinstance(message, str):
|
|
pass
|
|
else:
|
|
logger.warning('Can\'t send message, message has to be a string or bytes. Given type is %s' % type(message))
|
|
return False
|
|
|
|
header = bytearray()
|
|
payload = encode_to_UTF8(message)
|
|
payload_length = len(payload)
|
|
|
|
# Normal payload
|
|
if payload_length <= 125:
|
|
header.append(FIN | opcode)
|
|
header.append(payload_length)
|
|
|
|
# Extended payload
|
|
elif payload_length >= 126 and payload_length <= 65535:
|
|
header.append(FIN | opcode)
|
|
header.append(PAYLOAD_LEN_EXT16)
|
|
header.extend(struct.pack(">H", payload_length))
|
|
|
|
# Huge extended payload
|
|
elif payload_length < 18446744073709551616:
|
|
header.append(FIN | opcode)
|
|
header.append(PAYLOAD_LEN_EXT64)
|
|
header.extend(struct.pack(">Q", payload_length))
|
|
|
|
else:
|
|
raise Exception("Message is too big. Consider breaking it into chunks.")
|
|
return
|
|
|
|
self.request.send(header + payload)
|
|
|
|
def read_http_headers(self):
|
|
headers = {}
|
|
# first line should be HTTP GET
|
|
http_get = self.rfile.readline().decode().strip()
|
|
assert http_get.upper().startswith('GET')
|
|
# remaining should be headers
|
|
while True:
|
|
header = self.rfile.readline().decode().strip()
|
|
if not header:
|
|
break
|
|
head, value = header.split(':', 1)
|
|
headers[head.lower().strip()] = value.strip()
|
|
return headers
|
|
|
|
def handshake(self):
|
|
headers = self.read_http_headers()
|
|
|
|
try:
|
|
assert headers['upgrade'].lower() == 'websocket'
|
|
except AssertionError:
|
|
self.keep_alive = False
|
|
return
|
|
|
|
try:
|
|
key = headers['sec-websocket-key']
|
|
except KeyError:
|
|
logger.warning("Client tried to connect but was missing a key")
|
|
self.keep_alive = False
|
|
return
|
|
|
|
response = self.make_handshake_response(key)
|
|
self.handshake_done = self.request.send(response.encode())
|
|
self.valid_client = True
|
|
self.server._new_client_(self)
|
|
|
|
@classmethod
|
|
def make_handshake_response(cls, key):
|
|
return \
|
|
'HTTP/1.1 101 Switching Protocols\r\n'\
|
|
'Upgrade: websocket\r\n' \
|
|
'Connection: Upgrade\r\n' \
|
|
'Sec-WebSocket-Accept: %s\r\n' \
|
|
'\r\n' % cls.calculate_response_key(key)
|
|
|
|
@classmethod
|
|
def calculate_response_key(cls, key):
|
|
GUID = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
|
|
hash = sha1(key.encode() + GUID.encode())
|
|
response_key = b64encode(hash.digest()).strip()
|
|
return response_key.decode('ASCII')
|
|
|
|
def finish(self):
|
|
self.server._client_left_(self)
|
|
|
|
|
|
def encode_to_UTF8(data):
|
|
try:
|
|
return data.encode('UTF-8')
|
|
except UnicodeEncodeError as e:
|
|
logger.error("Could not encode data to UTF-8 -- %s" % e)
|
|
return False
|
|
except Exception as e:
|
|
raise(e)
|
|
return False
|
|
|
|
|
|
def try_decode_UTF8(data):
|
|
try:
|
|
return data.decode('utf-8')
|
|
except UnicodeDecodeError:
|
|
return False
|
|
except Exception as e:
|
|
raise(e)
|