tanmaykm/pywebsock.html

## pywebsock.html
<!DOCTYPE html>
<html>
  <head>
		<title>Websocket Demo</title>
		<style>
			#messages {
				border: dotted 1px #444444;
				font: 12px arial,sans-serif;
			}

			#messages > p {
				padding: 0px;
				margin: 0px;
			}
		</style>

		<script>
			var messages;
			var form;
			var inputBox;

			function log_msg(msg) {
				var p = document.createElement("p");
				p.innerHTML = msg;
				messages.appendChild(p);
			}

			function doInit() {
				inputBox = document.getElementById("message");
				messages = document.getElementById("messages");
				form = document.getElementById("form");
		 		var s;
				try {
					var host = "ws://localhost:4545/";
					if(window.location.hostname) {
						host = "ws://" + window.location.hostname + ":4545/";
					}

					s = new WebSocket(host);

					s.onopen = function (e) { log_msg("connected..."); };
					s.onclose = function (e) { log_msg("connection closed."); };
					s.onerror = function (e) { log_msg("connection error."); };
					s.onmessage = function (e) { log_msg("message: " + e.data); };
				} catch (ex) {
					log_msg("connection exception:" + ex);
				}

				form.addEventListener("submit", function (e) {
					e.preventDefault();
					s.send(inputBox.value);
					inputBox.value = "";
				}, false);
			}
		</script>
	</head>
<body onload="doInit()">
	<form id="form">
		<input type="text" id="message">
		<button type="submit">Send</button>
	</form>
	<br/>
	<div id="messages"></div>
</body>
</html>

## pywebsock.py
#!/usr/bin/env python

import socket, hashlib, base64, threading

class PyWSock:
    MAGIC = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
    HSHAKE_RESP = "HTTP/1.1 101 Switching Protocols\r\n" + \
                "Upgrade: websocket\r\n" + \
                "Connection: Upgrade\r\n" + \
                "Sec-WebSocket-Accept: %s\r\n" + \
                "\r\n"
    LOCK = threading.Lock()

    clients = []

    def recv_data (self, client):
        # as a simple server, we expect to receive:
        #    - all data at one go and one frame
        #    - one frame at a time
        #    - text protocol
        #    - no ping pong messages
        data = bytearray(client.recv(512))
        if(len(data) < 6):
            raise Exception("Error reading data")
        # FIN bit must be set to indicate end of frame
        assert(0x1 == (0xFF & data[0]) >> 7)
        # data must be a text frame
        # 0x8 (close connection) is handled with assertion failure
        assert(0x1 == (0xF & data[0]))

        # assert that data is masked
        assert(0x1 == (0xFF & data[1]) >> 7)
        datalen = (0x7F & data[1])

        #print("received data len %d" %(datalen,))

        str_data = ''
        if(datalen > 0):
            mask_key = data[2:6]
            masked_data = data[6:(6+datalen)]
            unmasked_data = [masked_data[i] ^ mask_key[i%4] for i in range(len(masked_data))]
            str_data = str(bytearray(unmasked_data))
        return str_data

    def broadcast_resp(self, data):
        # 1st byte: fin bit set. text frame bits set.
        # 2nd byte: no mask. length set in 1 byte.
        resp = bytearray([0b10000001, len(data)])
        # append the data bytes
        for d in bytearray(data):
            resp.append(d)

        self.LOCK.acquire()
        for client in self.clients:
            try:
                client.send(resp)
            except:
                print("error sending to a client")
        self.LOCK.release()

    def parse_headers (self, data):
        headers = {}
        lines = data.splitlines()
        for l in lines:
            parts = l.split(": ", 1)
            if len(parts) == 2:
                headers[parts[0]] = parts[1]
        headers['code'] = lines[len(lines) - 1]
        return headers

    def handshake (self, client):
        print('Handshaking...')
        data = client.recv(2048)
        headers = self.parse_headers(data)
        print('Got headers:')
        for k, v in headers.iteritems():
            print k, ':', v

        key = headers['Sec-WebSocket-Key']
        resp_data = self.HSHAKE_RESP % ((base64.b64encode(hashlib.sha1(key+self.MAGIC).digest()),))
        print('Response: [%s]' % (resp_data,))
        return client.send(resp_data)

    def handle_client (self, client, addr):
        self.handshake(client)
        try:
            while 1:
                data = self.recv_data(client)
                print("received [%s]" % (data,))
                self.broadcast_resp(data)
        except Exception as e:
            print("Exception %s" % (str(e)))
        print('Client closed: ' + str(addr))
        self.LOCK.acquire()
        self.clients.remove(client)
        self.LOCK.release()
        client.close()

    def start_server (self, port):
        s = socket.socket()
        s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        s.bind(('', port))
        s.listen(5)
        while(1):
            print ('Waiting for connection...')
            conn, addr = s.accept()
            print ('Connection from: ' + str(addr))
            threading.Thread(target = self.handle_client, args = (conn, addr)).start()
            self.LOCK.acquire()
            self.clients.append(conn)
            self.LOCK.release()

ws = PyWSock()
ws.start_server(4545)
	<!DOCTYPE html>
	<html>
	<head>
	<title>Websocket Demo</title>
	<style>
	#messages {
	border: dotted 1px #444444;
	font: 12px arial,sans-serif;
	}

	#messages > p {
	padding: 0px;
	margin: 0px;
	}
	</style>

	<script>
	var messages;
	var form;
	var inputBox;

	function log_msg(msg) {
	var p = document.createElement("p");
	p.innerHTML = msg;
	messages.appendChild(p);
	}

	function doInit() {
	inputBox = document.getElementById("message");
	messages = document.getElementById("messages");
	form = document.getElementById("form");
	var s;
	try {
	var host = "ws://localhost:4545/";
	if(window.location.hostname) {
	host = "ws://" + window.location.hostname + ":4545/";
	}

	s = new WebSocket(host);

	s.onopen = function (e) { log_msg("connected..."); };
	s.onclose = function (e) { log_msg("connection closed."); };
	s.onerror = function (e) { log_msg("connection error."); };
	s.onmessage = function (e) { log_msg("message: " + e.data); };
	} catch (ex) {
	log_msg("connection exception:" + ex);
	}

	form.addEventListener("submit", function (e) {
	e.preventDefault();
	s.send(inputBox.value);
	inputBox.value = "";
	}, false);
	}
	</script>
	</head>
	<body onload="doInit()">
	<form id="form">
	<input type="text" id="message">
	<button type="submit">Send</button>
	</form>
	<br/>
	<div id="messages"></div>
	</body>
	</html>
	#!/usr/bin/env python

	import socket, hashlib, base64, threading

	class PyWSock:
	MAGIC = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
	HSHAKE_RESP = "HTTP/1.1 101 Switching Protocols\r\n" + \
	"Upgrade: websocket\r\n" + \
	"Connection: Upgrade\r\n" + \
	"Sec-WebSocket-Accept: %s\r\n" + \
	"\r\n"
	LOCK = threading.Lock()

	clients = []

	def recv_data (self, client):
	# as a simple server, we expect to receive:
	# - all data at one go and one frame
	# - one frame at a time
	# - text protocol
	# - no ping pong messages
	data = bytearray(client.recv(512))
	if(len(data) < 6):
	raise Exception("Error reading data")
	# FIN bit must be set to indicate end of frame
	assert(0x1 == (0xFF & data[0]) >> 7)
	# data must be a text frame
	# 0x8 (close connection) is handled with assertion failure
	assert(0x1 == (0xF & data[0]))

	# assert that data is masked
	assert(0x1 == (0xFF & data[1]) >> 7)
	datalen = (0x7F & data[1])

	#print("received data len %d" %(datalen,))

	str_data = ''
	if(datalen > 0):
	mask_key = data[2:6]
	masked_data = data[6:(6+datalen)]
	unmasked_data = [masked_data[i] ^ mask_key[i%4] for i in range(len(masked_data))]
	str_data = str(bytearray(unmasked_data))
	return str_data

	def broadcast_resp(self, data):
	# 1st byte: fin bit set. text frame bits set.
	# 2nd byte: no mask. length set in 1 byte.
	resp = bytearray([0b10000001, len(data)])
	# append the data bytes
	for d in bytearray(data):
	resp.append(d)

	self.LOCK.acquire()
	for client in self.clients:
	try:
	client.send(resp)
	except:
	print("error sending to a client")
	self.LOCK.release()

	def parse_headers (self, data):
	headers = {}
	lines = data.splitlines()
	for l in lines:
	parts = l.split(": ", 1)
	if len(parts) == 2:
	headers[parts[0]] = parts[1]
	headers['code'] = lines[len(lines) - 1]
	return headers

	def handshake (self, client):
	print('Handshaking...')
	data = client.recv(2048)
	headers = self.parse_headers(data)
	print('Got headers:')
	for k, v in headers.iteritems():
	print k, ':', v

	key = headers['Sec-WebSocket-Key']
	resp_data = self.HSHAKE_RESP % ((base64.b64encode(hashlib.sha1(key+self.MAGIC).digest()),))
	print('Response: [%s]' % (resp_data,))
	return client.send(resp_data)

	def handle_client (self, client, addr):
	self.handshake(client)
	try:
	while 1:
	data = self.recv_data(client)
	print("received [%s]" % (data,))
	self.broadcast_resp(data)
	except Exception as e:
	print("Exception %s" % (str(e)))
	print('Client closed: ' + str(addr))
	self.LOCK.acquire()
	self.clients.remove(client)
	self.LOCK.release()
	client.close()

	def start_server (self, port):
	s = socket.socket()
	s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
	s.bind(('', port))
	s.listen(5)
	while(1):
	print ('Waiting for connection...')
	conn, addr = s.accept()
	print ('Connection from: ' + str(addr))
	threading.Thread(target = self.handle_client, args = (conn, addr)).start()
	self.LOCK.acquire()
	self.clients.append(conn)
	self.LOCK.release()

	ws = PyWSock()
	ws.start_server(4545)