Files
noVNC/utils/websocket.py
Joel Martin a0315ab1dc wsproxy: multiprocess capable.
Add -m, --multiprocess option which forks a handler for each
connection allowing multiple connections to the same target using the
same proxy instance.

Cleaned up the output of the handler process. Each process' output is
prefixed with an ordinal value.

Changed both the C and python versions of the proxy.
2010-09-10 13:05:48 -05:00

234 lines
6.9 KiB
Python
Executable File

#!/usr/bin/python
'''
Python WebSocket library with support for "wss://" encryption.
Copyright 2010 Joel Martin
Licensed under LGPL version 3 (see docs/LICENSE.LGPL-3)
You can make a cert/key with openssl using:
openssl req -new -x509 -days 365 -nodes -out self.pem -keyout self.pem
as taken from http://docs.python.org/dev/library/ssl.html#certificates
'''
import sys, socket, ssl, struct, traceback
import os, resource, errno, signal # daemonizing
from base64 import b64encode, b64decode
try:
from hashlib import md5
except:
from md5 import md5 # Support python 2.4
from urlparse import urlsplit
from cgi import parse_qsl
settings = {
'listen_host' : '',
'listen_port' : None,
'handler' : None,
'handler_id' : 1,
'cert' : None,
'ssl_only' : False,
'daemon' : True,
'multiprocess': False,
'record' : None, }
server_handshake = """HTTP/1.1 101 Web Socket Protocol Handshake\r
Upgrade: WebSocket\r
Connection: Upgrade\r
%sWebSocket-Origin: %s\r
%sWebSocket-Location: %s://%s%s\r
%sWebSocket-Protocol: sample\r
\r
%s"""
policy_response = """<cross-domain-policy><allow-access-from domain="*" to-ports="*" /></cross-domain-policy>\n"""
class EClose(Exception):
pass
def traffic(token="."):
if not settings['daemon'] and not settings['multiprocess']:
sys.stdout.write(token)
sys.stdout.flush()
def handler_msg(msg):
if not settings['daemon']:
if settings['multiprocess']:
print " %d: %s" % (settings['handler_id'], msg)
else:
print " %s" % msg
def encode(buf):
buf = b64encode(buf)
return "\x00%s\xff" % buf
def decode(buf):
""" Parse out WebSocket packets. """
if buf.count('\xff') > 1:
return [b64decode(d[1:]) for d in buf.split('\xff')]
else:
return [b64decode(buf[1:-1])]
def parse_handshake(handshake):
ret = {}
req_lines = handshake.split("\r\n")
if not req_lines[0].startswith("GET "):
raise Exception("Invalid handshake: no GET request line")
ret['path'] = req_lines[0].split(" ")[1]
for line in req_lines[1:]:
if line == "": break
var, val = line.split(": ")
ret[var] = val
if req_lines[-2] == "":
ret['key3'] = req_lines[-1]
return ret
def gen_md5(keys):
key1 = keys['Sec-WebSocket-Key1']
key2 = keys['Sec-WebSocket-Key2']
key3 = keys['key3']
spaces1 = key1.count(" ")
spaces2 = key2.count(" ")
num1 = int("".join([c for c in key1 if c.isdigit()])) / spaces1
num2 = int("".join([c for c in key2 if c.isdigit()])) / spaces2
return md5(struct.pack('>II8s', num1, num2, key3)).digest()
def do_handshake(sock):
# Peek, but don't read the data
handshake = sock.recv(1024, socket.MSG_PEEK)
#handler_msg("Handshake [%s]" % repr(handshake))
if handshake == "":
handler_msg("ignoring empty handshake")
sock.close()
return False
elif handshake.startswith("<policy-file-request/>"):
handshake = sock.recv(1024)
handler_msg("Sending flash policy response")
sock.send(policy_response)
sock.close()
return False
elif handshake.startswith("\x16"):
retsock = ssl.wrap_socket(
sock,
server_side=True,
certfile=settings['cert'],
ssl_version=ssl.PROTOCOL_TLSv1)
scheme = "wss"
handler_msg("using SSL/TLS")
elif settings['ssl_only']:
handler_msg("non-SSL connection disallowed")
sock.close()
return False
else:
retsock = sock
scheme = "ws"
handler_msg("using plain (not SSL) socket")
handshake = retsock.recv(4096)
#handler_msg("handshake: " + repr(handshake))
h = parse_handshake(handshake)
if h.get('key3'):
trailer = gen_md5(h)
pre = "Sec-"
handler_msg("using protocol version 76")
else:
trailer = ""
pre = ""
handler_msg("using protocol version 75")
response = server_handshake % (pre, h['Origin'], pre, scheme,
h['Host'], h['path'], pre, trailer)
#handler_msg("sending response:", repr(response))
retsock.send(response)
return retsock
def daemonize(keepfd=None):
os.umask(0)
os.chdir('/')
os.setgid(os.getgid()) # relinquish elevations
os.setuid(os.getuid()) # relinquish elevations
# Double fork to daemonize
if os.fork() > 0: os._exit(0) # Parent exits
os.setsid() # Obtain new process group
if os.fork() > 0: os._exit(0) # Parent exits
# Signal handling
def terminate(a,b): os._exit(0)
signal.signal(signal.SIGTERM, terminate)
signal.signal(signal.SIGINT, signal.SIG_IGN)
# Close open files
maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
if maxfd == resource.RLIM_INFINITY: maxfd = 256
for fd in reversed(range(maxfd)):
try:
if fd != keepfd:
os.close(fd)
else:
print "Keeping fd: %d" % fd
except OSError, exc:
if exc.errno != errno.EBADF: raise
# Redirect I/O to /dev/null
os.dup2(os.open(os.devnull, os.O_RDWR), sys.stdin.fileno())
os.dup2(os.open(os.devnull, os.O_RDWR), sys.stdout.fileno())
os.dup2(os.open(os.devnull, os.O_RDWR), sys.stderr.fileno())
def start_server():
lsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
lsock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
lsock.bind((settings['listen_host'], settings['listen_port']))
lsock.listen(100)
if settings['daemon']:
daemonize(keepfd=lsock.fileno())
if settings['multiprocess']:
print 'Waiting for connections on %s:%s' % (
settings['listen_host'], settings['listen_port'])
# Reep zombies
signal.signal(signal.SIGCHLD, signal.SIG_IGN)
while True:
try:
csock = startsock = None
pid = 0
if not settings['multiprocess']:
print 'Waiting for connection on %s:%s' % (
settings['listen_host'], settings['listen_port'])
startsock, address = lsock.accept()
handler_msg('got client connection from %s' % address[0])
csock = do_handshake(startsock)
if not csock: continue
if settings['multiprocess']:
handler_msg("forking handler process")
pid = os.fork()
if pid == 0: # handler process
settings['handler'](csock)
else: # parent process
settings['handler_id'] += 1
except EClose, exc:
handler_msg("handler exit: %s" % exc.args)
except Exception, exc:
handler_msg("handler exception: %s" % str(exc))
#handler_msg(traceback.format_exc())
if pid == 0:
if csock: csock.close()
if startsock and startsock != csock: startsock.close()
if settings['multiprocess']: break # Child process exits