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Copy pathwebsocket.py
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432 lines (380 loc) · 15.3 KB
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import collections
import string
import struct
from base64 import b64encode
import sys
def is_py3():
return sys.hexversion >= 0x3000000
if is_py3():
from itertools import cycle
unicode = str
else:
from itertools import cycle
from itertools import imap as map
from itertools import izip as zip
import random
import socket
try:
from hashlib import md5, sha1
except ImportError: #pragma NO COVER
from md5 import md5
from sha import sha as sha1
from meinheld import server, patch
from meinheld.common import Continuation, CLIENT_KEY, CONTINUATION_KEY
patch.patch_socket()
import socket
def _wsgi_to_bytes(s):
if isinstance(s, bytes):
return s
else:
return s.encode('iso-8859-1')
def _extract_comma(value):
return [x.strip() for x in value.split(',')]
class WebSocketMiddleware(object):
def __init__(self, app):
self.app = app
def _extract_number(self, value):
out = ""
spaces = 0
for char in value:
if char in string.digits:
out += char
elif char == " ":
spaces += 1
return int(out) / spaces
def setup(self, environ):
protocol_version = None
if not ("Upgrade" in _extract_comma(environ.get('HTTP_CONNECTION','')) and
environ.get('HTTP_UPGRADE','').lower() == 'websocket'):
return
if 'HTTP_SEC_WEBSOCKET_KEY' in environ:
protocol_version = environ['HTTP_SEC_WEBSOCKET_VERSION'] # RFC 6455
if protocol_version in ('13',): #skip version 4,5,6,7,8
protocol_version = int(protocol_version)
else:
# Unknown
raise NotImplementedError("Not Supported")
else:
raise NotImplementedError("Not Supported")
# Get the underlying socket and wrap a WebSocket class around it
client = environ[CLIENT_KEY]
sock = socket.fromfd(client.get_fd(), socket.AF_INET, socket.SOCK_STREAM)
ws = WebSocket(sock, environ, protocol_version)
# If it's new-version, we need to work out our challenge response
key1 = _wsgi_to_bytes(environ['HTTP_SEC_WEBSOCKET_KEY'])
key2 = _wsgi_to_bytes('258EAFA5-E914-47DA-95CA-C5AB0DC85B11')
digest = sha1(key1 + key2).digest()
response = b64encode(digest).strip()
if is_py3():
response = response.decode("iso-8859-1")
# Start building the response
location = 'ws://%s%s%s' % (
environ.get('HTTP_HOST'),
environ.get('SCRIPT_NAME'),
environ.get('PATH_INFO')
)
qs = environ.get('QUERY_STRING')
if qs:
location += '?' + qs
if protocol_version == 13:
handshake_reply = ("HTTP/1.1 101 Switching Protocols\r\n"
"Upgrade: websocket\r\n"
"Connection: Upgrade\r\n"
"Origin: %s\r\n"
"Sec-WebSocket-Accept: %s\r\n"
"\r\n"% (
environ.get('HTTP_ORIGIN'),
response))
if 'HTTP_SEC_WEBSOCKET_PROTOCOL' in environ:
handshake_reply += 'Sec-WebSocket-Protocol: %s\r\n' % environ.get('HTTP_SEC_WEBSOCKET_PROTOCOL')
else: #pragma NO COVER
raise ValueError("Unknown WebSocket protocol version.")
sock.sendall(_wsgi_to_bytes(handshake_reply))
environ['wsgi.websocket'] = ws
return True
def spawn_call(self, environ, start_response):
result = self.setup(environ)
response = None
try:
response = self.app(environ, start_response)
return response
finally:
if result and response != -1:
ws = environ.pop('wsgi.websocket')
ws._send_closing_frame(True)
client = environ[CLIENT_KEY]
client.set_closed(1)
def __call__(self, environ, start_response):
client = environ[CLIENT_KEY]
c = Continuation(client)
environ[CONTINUATION_KEY] = c
return self.spawn_call(environ, start_response)
class WebSocketWSGI(object):
def __init__(self, handler):
self.handler = handler
self.protocol_version = None
def __call__(self, environ, start_response):
if not ("Upgrade" in _extract_comma(environ.get('HTTP_CONNECTION','')) and
environ.get('HTTP_UPGRADE','').lower() == 'websocket'):
# need to check a few more things here for true compliance
start_response('400 Bad Request', [('Connection','close')])
return [""]
if 'HTTP_SEC_WEBSOCKET_KEY' in environ:
protocol_version = environ['HTTP_SEC_WEBSOCKET_VERSION'] # RFC 6455
if protocol_version in ('13',): #skip version 4,5,6,7,8
protocol_version = int(protocol_version)
else:
# Unknown
raise NotImplementedError("Not Supported")
else:
# Unknown
raise NotImplementedError("Not Supported")
# Get the underlying socket and wrap a WebSocket class around it
client = environ[CLIENT_KEY]
sock = server._get_socket_fromfd(client.get_fd(), socket.AF_INET,
socket.SOCK_STREAM)
ws = WebSocket(sock, environ, self.protocol_version)
# If it's new-version, we need to work out our challenge response
key1 = _wsgi_to_bytes(environ['HTTP_SEC_WEBSOCKET_KEY'])
key2 = _wsgi_to_bytes('258EAFA5-E914-47DA-95CA-C5AB0DC85B11)')
8000
digest = sha1(key1 + key2).digest()
response = b64encode(digest).strip()
if is_py3():
response = response.decode("iso-8859-1")
# Start building the response
location = 'ws://%s%s%s' % (
environ.get('HTTP_HOST'),
environ.get('SCRIPT_NAME'),
environ.get('PATH_INFO')
)
qs = environ.get('QUERY_STRING')
if qs:
location += '?' + qs
if protocol_version == 13:
handshake_reply = ("HTTP/1.1 101 Switching Protocols\r\n"
"Upgrade: websocket\r\n"
"Connection: Upgrade\r\n"
"Origin: %s\r\n"
"Sec-WebSocket-Accept: %s\r\n"
"\r\n"% (
environ.get('HTTP_ORIGIN'),
response))
if 'HTTP_SEC_WEBSOCKET_PROTOCOL' in environ:
handshake_reply += 'Sec-WebSocket-Protocol: %s\r\n' % environ.get('HTTP_SEC_WEBSOCKET_PROTOCOL')
else: #pragma NO COVER
raise ValueError("Unknown WebSocket protocol version.")
r = sock.sendall(_wsgi_to_bytes(handshake_reply))
self.handler(ws)
# Make sure we send the closing frame
ws._send_closing_frame(True)
# use this undocumented feature of eventlet.wsgi to ensure that it
# doesn't barf on the fact that we didn't call start_response
return [""]
def _extract_number(self, value):
"""
Utility function which, given a string like 'g98sd 5[]221@1', will
return 9852211. Used to parse the Sec-WebSocket-Key headers.
"""
out = ""
spaces = 0
for char in value:
if char in string.digits:
out += char
elif char == " ":
spaces += 1
return int(out) / spaces
class WebSocket(object):
"""A websocket object that handles the details of
serialization/deserialization to the socket.
The primary way to interact with a :class:`WebSocket` object is to
call :meth:`send` and :meth:`wait` in order to pass messages back
and forth with the browser. Also available are the following
properties:
path
The path value of the request. This is the same as the WSGI PATH_INFO variable, but more convenient.
protocol
The value of the Websocket-Protocol header.
origin
The value of the 'Origin' header.
environ
The full WSGI environment for this request.
"""
def __init__(self, sock, environ, version=76):
"""
:param socket: The eventlet socket
:type socket: :class:`eventlet.greenio.GreenSocket`
:param environ: The wsgi environment
:param version: The WebSocket spec version to follow (default is 76)
"""
self.socket = sock
self.origin = environ.get('HTTP_ORIGIN')
self.protocol = environ.get('HTTP_WEBSOCKET_PROTOCOL')
self.path = environ.get('PATH_INFO')
self.environ = environ
self.version = version
self.websocket_closed = False
self._buf = b""
self._msgs = collections.deque()
#self._sendlock = semaphore.Semaphore()
def _pack_message(self, message):
"""Pack the message inside ``00`` and ``FF``
As per the dataframing section (5.3) for the websocket spec
"""
if self.version in (13,):
# payload
opcode = 2
if isinstance(message, unicode): # text
opcode = 1
payload = message.encode('utf-8')
else:
payload = message
if not isinstance(payload, bytes):
raise TypeError("message should be str, unicode or bytes.")
# header(fin,maskflag,opcode,length)
fin = 0x80 #0x80:fin, 0:continuation
mask = 0 #0:unmasked, 0x80:masked
length = len(payload)
if length < 126:
header = struct.pack(">BB", fin|opcode, mask|length)
elif 126 <= length <= 0xffff:
header = struct.pack(">BBH", fin|opcode, mask|126, length)
elif 0xffff < length <= 0xffffffffffffffff:
header = struct.pack(">BBQ", fin|opcode, mask|127, length)
else:
#TODO: partial packet
raise ValueError("Can't send over 64bit length. (partial packet are not supported)")
# maskdata, masked-payload
maskdata = b''
if mask:
maskdata = struct.pack(">I", random.randint(0,0xffffffff))
masklist = cycle(ord(x) for x in maskdata)
payload = b''.join(chr(ord(d)^m) for d,m in zip(payload, masklist))
packed = header + maskdata + payload
else:
raise ValueError("Unknown WebSocket protocol version.")
return packed
def _parse_messages(self):
""" Parses for messages in the buffer *buf*. It is assumed that
the buffer contains the start character for a message, but that it
may contain only part of the rest of the message.
Returns an array of messages, and the buffer remainder that
didn't contain any full messages.
"""
if self.version not in (13,):
raise ValueError("Unknown WebSocket protocol version.")
msgs = []
buf = self._buf
msg = None
is_text = False
while True:
idx = 0
if len(buf) < idx+2:
return msgs
if is_py3():
b1, b2 = buf[idx], buf[idx+1]
else:
b1, b2 = ord(buf[idx]), ord(buf[idx+1])
idx += 2
fin = bool(b1 & 0x80) #TODO with opcode==0
opcode = b1 & 0x0f
mask = bool(b2 & 0x80)
length = (b2 & 0x7f)
if length == 126:
if len(buf) < idx+2:
return msgs
length = struct.unpack('>H', buf[idx:idx+2])[0]
idx += 2
elif length == 127:
if len(buf) < idx+8:
return msgs
length = struct.unpack('>Q', buf[idx:idx+8])[0]
idx += 8
if mask:
if len(buf) < idx + 4:
return msgs
maskdata = buf[idx:idx+4]
idx += 4
if len(buf) < idx + length:
return msgs
data = buf[idx:idx+length]
idx += length
if mask:
if is_py3():
data = ''.join(chr(d^m) for d,m in zip(data, cycle(maskdata)))
data = data.encode('iso-8859-1')
else:
data = b''.join(chr(d^m) for d,m in zip(
map(ord, data),
cycle(map(ord, maskdata))
))
print(opcode, length, data[:16])
if opcode == 0: #continuation
if is_text:
msg += data.decode('utf-8')
else:
msg += data
elif opcode == 1: #text
is_text = True
msg = data.decode('utf-8')
elif opcode == 2: #binary
is_text = False
msg = data
elif opcode == 8: #close
self.websocket_closed = True
#TODO process 2byte close status
break
elif opcode == 9: #ping
pass #TODO
elif opcode == 10: #pong
pass #TODO
else:
raise ValueError("Don't understand how to parse this type of message: %r, %s" % (buf, idx))
self._buf = buf = buf[idx:]
if fin:
msgs.append(msg)
msg = None
return msgs
def send(self, message):
"""Send a message to the browser. *message* should be
convertable to a string; unicode objects should be encodable
as utf-8."""
packed = self._pack_message(message)
# if two greenthreads are trying to send at the same time
# on the same socket, sendlock prevents interleaving and corruption
#self._sendlock.acquire()
#try:
return self.socket.sendall(packed)
#finally:
# self._sendlock.release()
def wait(self):
"""Waits for and deserializes messages. Returns a single
message; the oldest not yet processed."""
while not self._msgs:
# Websocket might be closed already.
if self.websocket_closed:
return None
# no parsed messages, must mean buf needs more data
delta = self.socket.recv(8096)
if delta == b'':
return None
self._buf += delta
msgs = self._parse_messages()
self._msgs.extend(msgs)
return self._msgs.popleft()
def _send_closing_frame(self, ignore_send_errors=False):
"""Sends the closing frame to the client, if required."""
if self.version == 76 and not self.websocket_closed:
try:
self.socket.send("\xff\x00")
except IOError:
# Sometimes, like when the remote side cuts off the connection,
# we don't care about this.
if not ignore_send_errors: #pragma NO COVER
raise
self.websocket_closed = True
def close(self):
"""Forcibly close the websocket; generally it is preferable to
return from the handler method."""
self._send_closing_frame()
self.socket.shutdown(True)
self.socket.close()