# websockify proxy to serve noVNC (http://kanaka.github.com/noVNC/)
# with Apache + mod_python + pywebsocket
# Inspired by websockify project (https://github.com/kanaka/websockify)
#
# Supports noVNC path feature
# but in different way than original websockify do:
# GET parameters have to be specified
# like http://your.host.dom/vnc/ws/websockify?host=localhost&port=5900
#  or just http://your.host.dom/vnc/ws/websockify?port=5900
#  as localhost is default
#
# Created by Daniel Podolsky, [email protected], 22 Nov 2011
#
# Install
# 1) Install Apache 2.2 (http://httpd.apache.org/) with mod_python
# 2) Install pywebsocket (http://code.google.com/p/pywebsocket/)
# 3) Place websockify_wsh.py somewhere. Say, /var/www/vnc/ws/websockify_wsh.py
# 4) Configure apache:
#   PythonOption mod_pywebsocket.handler_root /var/www/vnc
#   PythonOption mod_pywebsocket.handler_scan /var/www/vnc/ws
#   
#   <Location /vnc/ws>
#     PythonHeaderParserHandler mod_pywebsocket.headerparserhandler
#     PythonDebug On
#   </Location>
#
# Note: 'PythonOption mod_pywebsocket.handler_*' must be placed
#  in the global Apache config scope
# (see http://www.mailinglistarchive.com/html/[email protected]/2006-09/msg00720.html)

import socket

from sys             import exc_info
from urlparse        import parse_qs
from base64          import b64encode, b64decode
from mod_python      import apache
from mod_pywebsocket import msgutil

def list_value(array, key, def_val=None):
    if key in array:
        return array[key]
    if def_val is not None:
        return def_val
    raise ValueError("websockify: '%s' is not specified" % (key))


def web_socket_do_extra_handshake(request):
    request.ws_protocol = request.ws_requested_protocols[0]
    request.log_error("websockify: ws_protocol = '%s' (%s)" % (request.ws_protocol, request.ws_requested_protocols), apache.APLOG_DEBUG)
    pass  # Always accept.

def web_socket_transfer_data(request):
    args_parsed = parse_qs(request.args, False, True)

    target_port = list_value(args_parsed, 'port')[0]
    target_host = list_value(args_parsed, 'host', def_val=['localhost'])[0]

    target = connect(target_host, target_port)

    request.log_error("websockify: %s:%s connected" % (target_host,target_port), apache.APLOG_INFO)

    try:
        do_proxy("%s:%s" % (target_host, target_port), request, target)
    except:
        if target:
            target.shutdown(socket.SHUT_RDWR)
            target.close()
        raise

def do_proxy(sock_name, request, target):
    buffer_size = 65536

    def read_message(message):
        buf  = b64decode(message)
        request.log_error("websockify: %s %d (%d decoded) bytes come from client" % (sock_name, len(message), len(buf)), apache.APLOG_DEBUG)
        sent = 0
        while (sent < len(buf)):
            sent += target.send(buf[sent:])
            request.log_error("websockify: %s %d of %d bytes passed to backend" % (sock_name, sent, len(buf)), apache.APLOG_DEBUG)

    receiver = msgutil.MessageReceiver(request, read_message)

    while True:
        message = target.recv(buffer_size)
        if len(message) == 0:
            raise socket.error('websockify: %s backend connection closed unexpectedly' % (sock_name))
        buf = b64encode(message)
        request.ws_stream.send_message(buf, binary=False)
        request.log_error("websockify: %s %d (%d encoded) bytes passed to client" % (sock_name, len(message), len(buf)), apache.APLOG_DEBUG)

def connect(host, port):
    try:
        return socket.create_connection((socket.gethostbyname(host), port))
    except:
        raise socket.error("websockify: can not connect to '%s:%s': %s" % (host, port, exc_info()[1]))

# vi:sts=4 sw=4 et

# websockify proxy to serve noVNC (http://kanaka.github.com/noVNC/)
# with Apache + mod_python + pywebsocket
# Inspired by websockify project (https://github.com/kanaka/websockify)
#
# Supports noVNC path feature
# but in different way than original websockify do:
# GET parameter have to be specified
# like http://your.host.dom/vnc/ws/websockify?host=hostName
#
# hostName must be defined in the vncHosts file (see below)
#
# Install
# 1) Install Apache 2.2 (http://httpd.apache.org/) with mod_python
# 2) Install pywebsocket (http://code.google.com/p/pywebsocket/)
# 3) Place websockify_wsh.py somewhere. Say, /var/www/vnc/ws/websockify_wsh.py
# 4) Configure apache:
#   PythonOption mod_pywebsocket.handler_root /var/www/vnc
#   PythonOption mod_pywebsocket.handler_scan /var/www/vnc/ws
#   # Note: 'PythonOption mod_pywebsocket.handler_*' lines have to be placed
#   #  in the global Apache config scope
#   # (see http://www.mailinglistarchive.com/html/[email protected]/2006-09/msg00720.html)
#   
#   <Location /vnc/ws>
#     PythonOption websockify.vncHosts /etc/vncHosts
#
#     PythonHeaderParserHandler mod_pywebsocket.headerparserhandler
#     PythonDebug On
#   </Location>
# 5) Create vncHosts file:
#   [vncHosts] # Just to satisfy Python ConfigParser
#   hostName1 = ipOrName1:portNumber1
#   hostName2 = ipOrName2:portNumber2
#   ...
#
# Created by Daniel Podolsky, [email protected], 22 Nov 2011

import socket
import ConfigParser

from sys             import exc_info
from urlparse        import parse_qs
from base64          import b64encode, b64decode
from mod_python      import apache
from mod_pywebsocket import msgutil, handshake

def list_value(array, key, def_val=None):
    if key in array:
        return array[key]
    if def_val is not None:
        return def_val
    raise ValueError("key '%s' is not specified" % (key))

def web_socket_do_extra_handshake(request):
    try:
      request.add_common_vars()

      request.subprocess_env['vncHostName'] = list_value(parse_qs(request.args, False, True), 'host')[0]

      config = ConfigParser.ConfigParser()
      config.read(list_value(request.get_options(), 'websockify.vncHosts'))

      vncHost = config.get('vncHosts', request.subprocess_env['vncHostName']).split(':', 2)

      request.subprocess_env['vncHostAddr'] = vncHost[0]
      request.subprocess_env['vncHostPort'] = vncHost[1]
    except:
      raise handshake.AbortedByUserException("websockify: connection denied: %s" % (exc_info()[1]))

    request.ws_protocol = request.ws_requested_protocols[0]
    request.log_error("websockify: ws_protocol = '%s' (%s)" % (request.ws_protocol, request.ws_requested_protocols), apache.APLOG_INFO)

    pass  # Always accept.

def web_socket_transfer_data(request):
    target = connect(request.subprocess_env['vncHostAddr'], request.subprocess_env['vncHostPort'])

    sockName = "%s(%s:%s)" % (request.subprocess_env['vncHostName'],
                              request.subprocess_env['vncHostAddr'],
                              request.subprocess_env['vncHostPort']
                             )

    request.log_error("websockify: %s connected" % (sockName), apache.APLOG_NOTICE)

    try:
      do_proxy(sockName, request, target)
    except:
      if target:
        target.shutdown(socket.SHUT_RDWR)
        target.close()
      raise

def do_proxy(sock_name, request, target):
    buffer_size = 65536

    def read_message(message):
        buf  = b64decode(message)
        request.log_error("websockify: %s %d (%d decoded) bytes come from client" % (sock_name, len(message), len(buf)), apache.APLOG_DEBUG)
        sent = 0
        while (sent < len(buf)):
          sent += target.send(buf[sent:])
          request.log_error("websockify: %s %d of %d bytes passed to backend" % (sock_name, sent, len(buf)), apache.APLOG_DEBUG)

    receiver = msgutil.MessageReceiver(request, read_message)

    while True:
      message = target.recv(buffer_size)
      if len(message) == 0:
        raise socket.error('websockify: %s backend connection closed unexpectedly' % (sock_name))
      buf = b64encode(message)
      request.ws_stream.send_message(buf, binary=False)
      request.log_error("websockify: %s %d (%d encoded) bytes passed to client" % (sock_name, len(message), len(buf)), apache.APLOG_DEBUG)

def connect(host, port):
    try:
      return socket.create_connection((socket.gethostbyname(host), port))
    except:
      raise socket.error("websockify: can not connect to '%s:%s': %s" % (host, port, exc_info()[1]))

# vi:sts=4 sw=4 et