Determine the resolution for a series of VNC ports.

vlab-resolution.py

"""
    Determine the resolution for a series of VNC ports.

    Andrew Bennett <andrew.bennett@unsw.edu.au>
    Feb 2017

    Implementing the protocol from the RFC6143 spec:
      https://tools.ietf.org/html/rfc6143

    Width and Height:

      | No. of bytes | Type [Value] | Description    
      | 2            | U16          | framebuffer-width in pixels  |
      | 2            | U16          | framebuffer-height in pixels |
      | 16           | PIXEL_FORMAT | server-pixel-format          |
      | 4            | U32          | name-length                  |
      | name-length  | U8 array     | name-string   
"""

import socket
ports = [5911, 5912, 5913, 5914, 5915, 5916]


def recvs(s):
  recv = s.recv(1024)
  return recv

def sends(s, text):
  s.send(text)

def convert_wh(result):
  return int(result[0:2].encode('hex'), 16), int(result[2:4].encode('hex'), 16)

for port in ports:

  s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  s.connect(("vlab", port))
  # print "ProtocolVersion Handshake"
  recvs(s)
  sends(s, 'RFB 003.008\n')

  # print "Security Handshake"
  recvs(s)
  sends(s, '\x01\n')
  # print "SecurityResult Handshake"
  recvs(s)

  # print "ClientInit"
  sends(s, '\x01\n')

  # print "ServerInit"
  result = recvs(s)

  width, height = convert_wh(result[0:4])
  print "resolution for port %d is: %d x %d " % (port, width, height)