【python socket】实现websocket服务端

一、获取握手信息

首先通过如下代码，我们使用socket来获取客户端的握手信息

import socket

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(("127.0.0.1", 8002))
sock.listen(5)

conn, address = sock.accept()  # 获取客户端的socket对象和地址

msg = conn.recv(1024)  # 获取客户端的握手信息
print(msg)

我们可以通过http://www.websocket-test.com/来作为websocket客户端

当连接上服务端时，服务端打印如下信息

二、格式化websocket请求头

将上述打印信息转为JSON格式：

def get_headers(data):
    """
    将请求头格式化成字典
    :param data:
    :return:
    """
    header_dict = {}
    data = str(data, encoding='utf-8')

    # for i in data.split('\r\n'):
    #     print(i)
    header, body = data.split('\r\n\r\n', 1)
    header_list = header.split('\r\n')
    for i in range(0, len(header_list)):
        if i == 0:
            if len(header_list[i].split(' ')) == 3:
                header_dict['method'], header_dict['url'], header_dict['protocol'] = header_list[i].split(' ')
        else:
            k, v = header_list[i].split(':', 1)
            header_dict[k] = v.strip()
    return header_dict

调用上述方法可以将服务端收到的握手信息转为Json格式：

三、提取key并加密

key = headers_dict["Sec-WebSocket-Key"]  # 提取key

# 对key进行加密
magic_string = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
value = key + magic_string
ac = base64.b64encode(hashlib.sha1(value.encode('utf-8')).digest())
# print(ac)

四、将加密的结果返回客户端

# 将加密的结果返回客户端
response_tpl = "HTTP/1.1 101 Switching Protocols\r\n" \
      "Upgrade:websocket\r\n" \
      "Connection: Upgrade\r\n" \
      "Sec-WebSocket-Accept: %s\r\n" \
      "WebSocket-Location: ws://%s%s\r\n\r\n"
response_str = response_tpl % (ac.decode('utf-8'), headers_dict['Host'], headers_dict['url'])
conn.send(response_str.encode("utf-8"))

五、和客户端建立连接后的操作

这里建立连接后，将客户端发送的信息再返回给客户端

while True:
    try:
        info = conn.recv(8096)
    except Exception as e:
        info = None
    if not info:
        break
    payload_len = info[1] & 127
    if payload_len == 126:
        extend_payload_len = info[2:4]
        mask = info[4:8]
        decoded = info[8:]
    elif payload_len == 127:
        extend_payload_len = info[2:10]
        mask = info[10:14]
        decoded = info[14:]
    else:
        extend_payload_len = None
        mask = info[2:6]
        decoded = info[6:]

    bytes_list = bytearray()
    for i in range(len(decoded)):
        chunk = decoded[i] ^ mask[i % 4]
        bytes_list.append(chunk)
    body = str(bytes_list, encoding='utf-8')
    send_msg(conn, body.encode('utf-8'))

服务端完整代码

实现了服务端接收与发送的分离；

当服务端接收到指定字符串时（"exit"），服务端主动断开连接。

import socket,base64,hashlib,time,threading


def get_headers(data):
    """
    将请求头格式化成字典
    :param data:
    :return:
    """
    header_dict = {}
    data = str(data, encoding='utf-8')

    # for i in data.split('\r\n'):
    #     print(i)
    header, body = data.split('\r\n\r\n', 1)
    header_list = header.split('\r\n')
    for i in range(0, len(header_list)):
        if i == 0:
            if len(header_list[i].split(' ')) == 3:
                header_dict['method'], header_dict['url'], header_dict['protocol'] = header_list[i].split(' ')
        else:
            k, v = header_list[i].split(':', 1)
            header_dict[k] = v.strip()
    return header_dict

def send_msg(conn, msg_bytes):
    """
    WebSocket服务端向客户端发送消息
    :param conn: 客户端连接到服务器端的socket对象,即： conn,address = socket.accept()
    :param msg_bytes: 向客户端发送的字节
    :return:
    """
    import struct

    token = b"\x81"
    length = len(msg_bytes)
    if length < 126:
        token += struct.pack("B", length)
    elif length <= 0xFFFF:
        token += struct.pack("!BH", 126, length)
    else:
        token += struct.pack("!BQ", 127, length)

    msg = token + msg_bytes
    conn.send(msg)
    return True

def recv_msg(conn):
    while True:
        try:
            info = conn.recv(8096)
        except Exception as e:
            info = None
        if not info:
            break
        payload_len = info[1] & 127
        if payload_len == 126:
            extend_payload_len = info[2:4]
            mask = info[4:8]
            decoded = info[8:]
        elif payload_len == 127:
            extend_payload_len = info[2:10]
            mask = info[10:14]
            decoded = info[14:]
        else:
            extend_payload_len = None
            mask = info[2:6]
            decoded = info[6:]

        bytes_list = bytearray()
        for i in range(len(decoded)):
            chunk = decoded[i] ^ mask[i % 4]
            bytes_list.append(chunk)
        global body
        body = str(bytes_list, encoding='utf-8')
        print(body)
        if body == "exit":
            conn.close()
            break

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(("127.0.0.1", 8002))
sock.listen(5)

conn, address = sock.accept()  # 获取客户端的socket对象和地址

data = conn.recv(1024)  # 获取客户端的握手信息
headers_dict = get_headers(data)
key = headers_dict["Sec-WebSocket-Key"]  # 提取key

# 对key进行加密
magic_string = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
value = key + magic_string
ac = base64.b64encode(hashlib.sha1(value.encode('utf-8')).digest())
# print(ac)

# 将加密的结果返回客户端
response_tpl = "HTTP/1.1 101 Switching Protocols\r\n" \
      "Upgrade:websocket\r\n" \
      "Connection: Upgrade\r\n" \
      "Sec-WebSocket-Accept: %s\r\n" \
      "WebSocket-Location: ws://%s%s\r\n\r\n"
response_str = response_tpl % (ac.decode('utf-8'), headers_dict['Host'], headers_dict['url'])
conn.send(response_str.encode("utf-8"))

# 和客户端建立连接后的操作

# 启动接收客户端信息的线程
thread_obj = threading.Thread(target=recv_msg, args=(conn,))
thread_obj.daemon = True
thread_obj.start()

# 不断给客户端发送信息
while True:
    if getattr(conn, "_closed") == False:  # 客户端没有关闭
        send_msg(conn, str("你好").encode('utf-8'))
        time.sleep(1)
    else:  # 客户端关闭
        break

参考视频链接：https://www.bilibili.com/video/BV1tf4y1K7Ww?p=8&spm_id_from=pageDriver&vd_source=36a3e35639c44bb339f59760641390a8

参考文章：https://www.cnblogs.com/wupeiqi/p/6558766.html