一. 客户端服务端进行握手

1.客户端向服务端发送握手包

GET ws://localhost:8000/ HTTP/1.1
Host: localhost:8000
Connection: Upgrade
Pragma: no-cache
Cache-Control: no-cache
Upgrade: websocket
Origin: http://localhost:63342
Sec-WebSocket-Version: 13
Accept-Encoding: gzip, deflate, sdch, br
Accept-Language: zh-CN,zh;q=0.8
Sec-WebSocket-Key: 60jj9YDlrvPB+DzLmVJzcg==
Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits复制代码

2.服务端进行回应,返回给客户端

HTTP/1.1 101 Switching Protocols
Upgrade: WebSocket
Connection: Upgrade
Sec-WebSocket-Accept: Cx7gYudkmGmF8rMFP1W1HbLkWRA=复制代码

客户端发送握手请求，然后服务端返回正确的数据，经过客户端的确认完成握手，然后就可以进行通信了；
这里客户端发送的Sec-WebSocket-Key是一个Base64 encode的值，它是浏览器随机生成的，然后服务端通过这个值生成一个Sec-WebSocket-Accept;
方法： key+'258EAFA5-E914-47DA-95CA-C5AB0DC85B11'，然后SHA-1加密，再进行base-64加密；
下面是握手代码：

HANDSHAKE_STR = ("HTTP/1.1 101 Switching Protocols\r\n""Upgrade: WebSocket\r\n""Connection: Upgrade\r\n""Sec-WebSocket-Accept: %(token)s\r\n\r\n"
)
GUID_STR = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
def parseHeaders(self, msg):# print(msg)headers = {}msg = str(msg, encoding="utf-8")header, data = msg.split('\r\n\r\n', 1)for x in header.split("\r\n")[1:]:# 这里是 “:+space”key, value = x.split(": ", 1)headers[key] = valuereturn headers
# 握手数据
def handShakeData(self,c_req):sec_key = self.parseHeaders(c_req)['Sec-WebSocket-Key']key = sec_key.encode("ascii") + GUID_STR.encode("ascii")accept_token = base64.b64encode(hashlib.sha1(key).digest()).decode("ascii")s_res = HANDSHAKE_STR % {'token': accept_token}return s_res复制代码

二. 进行通信

大概就是握手完成后，客户端发送消息到服务端，然后服务端将消息发送到每个连接上的客户端；

数据交互协议

  0                   1                   2                   30 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1+-+-+-+-+-------+-+-------------+-------------------------------+|F|R|R|R| opcode|M| Payload len |    Extended payload length    ||I|S|S|S|  (4)  |A|     (7)     |             (16/64)           ||N|V|V|V|       |S|             |   (if payload len==126/127)   || |1|2|3|       |K|             |                               |+-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +|     Extended payload length continued, if payload len == 127  |+ - - - - - - - - - - - - - - - +-------------------------------+|                               |Masking-key, if MASK set to 1  |+-------------------------------+-------------------------------+| Masking-key (continued)       |          Payload Data         |+-------------------------------- - - - - - - - - - - - - - - - +:                     Payload Data continued ...                :+ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +|                     Payload Data continued ...                |+---------------------------------------------------------------+复制代码

第一个字节：

• FIN：描述消息是否结束；占1bit；如果是1表示这是数据包的最后一帧，0则表示后续还有数据；
• RSV1, RSV2, RSV3：扩展定义，默认0，各占1bit;
• opcode：表示传输的数据包类型，占4bit,(15种情况)
  • 0x0 表示为附加数据
  • 0x1 表示为text类型数据
  • 0x2 表示binary类型数据
  • 0x3~7 暂未定义
  • 0x8 表示连接关闭
  • 0x9 表示ping类型数据
  • 0xA 表示pong类型数据
  • 0xB~F 暂未定义

第二个字节：

• MASK：表示是否经过掩码处理；如果是1，表示经过掩码处理，Masking-key的数据为掩码密码
• Payload length：
  • 如果值为0~125，则就是payload的真实长度；（若MASK=1,则Masking-key为第3~6个字节）
  • 如果值为126，则后面的2个字节（16bit）为payload的真实长度；（若MASK=1,则Masking-key为第5~8个字节）
  • 如果值为127，则后面的8个字节（64bit）为payload的真实长度；（若MASK=1,则Masking-key为第11~14个字节）

1. 将客户端发送的数据解析出真实的数据

方法：将Payload Data数据的每一位x,与Masking-key的第i%4位进行异或运算，i是x在Payload Data中的索引；
下面是解析的代码：

def parseData(self,msg):g_code_length = msg[1] & 127if g_code_length == 126:g_code_length = struct.unpack('!H', msg[2:4])[0]masks = msg[4:8]data = msg[8:]elif g_code_length == 127:g_code_length = struct.unpack('!Q', msg[2:10])[0]masks = msg[10:14]data = msg[14:]else:masks = msg[2:6]data = msg[6:]i = 0raw_by = bytearray()for d in data:raw_by.append( int(d) ^ int(masks[i % 4]) )i += 1print(u"总长度是：%d" % int(g_code_length))raw_str = raw_by.decode()return raw_str复制代码

2. 将数据发送到客户端

发送的数据格式：固定字节+包长度字节+原始数据
例：\x81\x0cHello World!

三. 完整的代码
服务端：

import socket
import base64,hashlib
import threading
import struct
from collections import dequeHANDSHAKE_STR = ("HTTP/1.1 101 Switching Protocols\r\n""Upgrade: WebSocket\r\n""Connection: Upgrade\r\n""Sec-WebSocket-Accept: %(token)s\r\n\r\n"
)
GUID_STR = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
STREAM = 0x0
TEXT = 0x1
BINARY = 0x2
CLOSE = 0x8
PING = 0x9
PONG = 0xAclass WebSocket(threading.Thread):def __init__(self,conn,addr,index):threading.Thread.__init__(self)self.index = indexself.conn = connself.addr = addr#发送的数据缓存self.buffer = bytearray()self.sendToClientData = deque()# 组装header 获取‘Sec-WebSocket-Key’def parseHeaders(self, msg):# print(msg)headers = {}msg = str(msg, encoding="utf-8")header, data = msg.split('\r\n\r\n', 1)for x in header.split("\r\n")[1:]:# 这里是 “:+space”key, value = x.split(": ", 1)headers[key] = valuereturn headers# 握手数据def handShakeData(self,c_req):sec_key = self.parseHeaders(c_req)['Sec-WebSocket-Key']key = sec_key.encode("ascii") + GUID_STR.encode("ascii")accept_token = base64.b64encode(hashlib.sha1(key).digest()).decode("ascii")s_res = HANDSHAKE_STR % {'token': accept_token}return s_res# 得到数据长度 （包含描述字节）def getMsglen(self,msg):g_code_length = msg[1] & 127if g_code_length == 126:g_code_length = struct.unpack('!H', msg[2:4])[0]g_code_length += 8elif g_code_length == 127:g_code_length = struct.unpack('!Q', msg[2:10])[0]g_code_length += 14else:g_code_length += 6g_code_length = int(g_code_length)print(g_code_length)return g_code_length# 解析数据def parseData(self,msg):g_code_length = msg[1] & 127if g_code_length == 126:g_code_length = struct.unpack('!H', msg[2:4])[0]masks = msg[4:8]data = msg[8:]elif g_code_length == 127:g_code_length = struct.unpack('!Q', msg[2:10])[0]masks = msg[10:14]data = msg[14:]else:masks = msg[2:6]data = msg[6:]i = 0raw_by = bytearray()for d in data:raw_by.append( int(d) ^ int(masks[i % 4]) )i += 1print(raw_by)print(u"总长度是：%d" % int(g_code_length))raw_str = raw_by.decode()# raw_str = str(raw_by)return raw_str# 发送消息def sendMessage(self,message):# 遍历连接上的列表for conn in connections.values():# 发送消息到client （除了自己）if conn != self.conn:self._sendMessage(False,TEXT,message)while self.sendToClientData:data = self.sendToClientData.popleft()conn.send(data[1])# FIN 后面是否还有数据；opcode 传输的数据包类型；message 传输的数据(str)def _sendMessage(self,FIN,opcode,message):payload = bytearray()b1 = 0b2 = 0if FIN is False:b1 |= 0x80b1 |= opcode        # 若opcode=TEXT    b'0x81'payload.append(b1)      #msg_utf = message.encode('utf-8')msg_len = len(msg_utf)if msg_len <= 125:b2 |= msg_lenpayload.append(b2)elif msg_len >= 126 and msg_len <= 65535:b2 |= 126payload.append(b2)payload.extend(struct.pack("!H", msg_len))elif msg_len <= (2 ^ 64 - 1):b2 |= 127payload.append(b2)payload.extend(struct.pack("!Q", msg_len))else:print("传输的数据太长了! ——(_sendMessage)")# 拼接上需要发送的数据# 格式大概这样：bytearray(b'\x81\x0cHello World!')   '\x0c'是发送的数据长度if msg_len > 0:payload.extend(msg_utf)self.sendToClientData.append((opcode,payload))# 端开连接def _disConnected(self):self.conn.close()print("断开的连接conn%s" % (self.index))print(connections)del connections['conn%s' % (self.index)]print(connections)# def run(self):# print(self.listeners)self.isHandShake = Falsewhile True:if self.isHandShake == False:print("start handshake %s" % (self.addr[0]))# 接收客户端内容c_req = self.conn.recv(1024)# print(c_req)handData = self.handShakeData(c_req)self.conn.sendall(str.encode(handData))self.isHandShake = Trueelse:message = self.conn.recv(16384)    # 16 * 1024   16384   # bytesprint(message)# 断开连接if message[0]&127 == CLOSE:    # 0x88   136self._disConnected()returnself.buffer.extend(message)  # bytescode_length = self.getMsglen(self.buffer)  # 数据中带的 数据长度（包含描述字节）# 数据完整就发送if code_length == len(self.buffer):buffer_utf = self.parseData(self.buffer)      # strself.sendMessage(buffer_utf)print(message)self.buffer = bytearray()connections = {}
class websocketServer(object):def __init__(self,host, port):self.serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)self.serversocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)self.serversocket.bind((host, port))self.serversocket.listen(5)def server(self):print(self.serversocket)index =0while True:conn,addr = self.serversocket.accept()print(conn)print(addr)# 新建线程newSocket = WebSocket(conn,addr,index)# 开始线程,执行run函数newSocket.start()connections['conn%s'% (index)] = connindex += 1print(connections)websocketServer = websocketServer("127.0.0.1",8000)
websocketServer.server()复制代码

感谢您的阅读；