l1n6yun's Blog

记录学习的技能和遇到的问题

0%

WebSocket协议

发表于 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
class WS {
    var $master;  // 连接 server 的 client
    var $sockets = array(); // 不同状态的 socket 管理
    var $handshake = false; // 判断是否握手

    function __construct($address, $port){
        // 建立一个 socket 套接字
        $this->master = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)   
            or die("socket_create() failed");
        socket_set_option($this->master, SOL_SOCKET, SO_REUSEADDR, 1)  
            or die("socket_option() failed");
        socket_bind($this->master, $address, $port)                    
            or die("socket_bind() failed");
        socket_listen($this->master, 2)                               
            or die("socket_listen() failed");

        $this->sockets[] = $this->master;

        // debug
        echo("Master socket  : ".$this->master."\n");

        while(true) {
            //自动选择来消息的 socket 如果是握手 自动选择主机
            $write = NULL;
            $except = NULL;
            socket_select($this->sockets, $write, $except, NULL);

            foreach ($this->sockets as $socket) {
                //连接主机的 client 
                if ($socket == $this->master){
                    $client = socket_accept($this->master);
                    if ($client < 0) {
                        // debug
                        echo "socket_accept() failed";
                        continue;
                    } else {
                        //connect($client);
                        array_push($this->sockets, $client);
                        echo "connect client\n";
                    }
                } else {
                    $bytes = @socket_recv($socket,$buffer,2048,0);
                    print_r($buffer);
                    if($bytes == 0) return;
                    if (!$this->handshake) {
                        // 如果没有握手，先握手回应
                        $this->doHandShake($socket, $buffer);
                        echo "shakeHands\n";
                    } else {
                    
                        // 如果已经握手，直接接受数据，并处理
                        $buffer = $this->decode($buffer);
                        //process($socket, $buffer); 
                        echo "send file\n";
                    }
                }
            }
        }
    }
    
    function dohandshake($socket, $req)
    {
        // 获取加密key
        $acceptKey = $this->encry($req);
        $upgrade = "HTTP/1.1 101 Switching Protocols\r\n" .
                   "Upgrade: websocket\r\n" .
                   "Connection: Upgrade\r\n" .
                   "Sec-WebSocket-Accept: " . $acceptKey . "\r\n" .
                   "\r\n";

        echo "dohandshake ".$upgrade.chr(0);           
        // 写入socket
        socket_write($socket,$upgrade.chr(0), strlen($upgrade.chr(0)));
        // 标记握手已经成功，下次接受数据采用数据帧格式
        $this->handshake = true;
    }
    
    
    function encry($req)
    {
        $key = $this->getKey($req);
        $mask = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";

        return base64_encode(sha1($key . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11', true));
    }
    
    function getKey($req) 
    {
        $key = null;
        if (preg_match("/Sec-WebSocket-Key: (.*)\r\n/", $req, $match)) { 
            $key = $match[1]; 
        }
        return $key;
    }
    
    // 解析数据帧
    function decode($buffer)  
    {
        $len = $masks = $data = $decoded = null;
        $len = ord($buffer[1]) & 127;

        if ($len === 126)  {
            $masks = substr($buffer, 4, 4);
            $data = substr($buffer, 8);
        } else if ($len === 127)  {
            $masks = substr($buffer, 10, 4);
            $data = substr($buffer, 14);
        } else  {
            $masks = substr($buffer, 2, 4);
            $data = substr($buffer, 6);
        }
        for ($index = 0; $index < strlen($data); $index++) {
            $decoded .= $data[$index] ^ $masks[$index % 4];
        }
        return $decoded;
    }
    
    // 返回帧信息处理
    function frame($s) 
    {
        $a = str_split($s, 125);
        if (count($a) == 1) {
            return "\x81" . chr(strlen($a[0])) . $a[0];
        }
        $ns = "";
        foreach ($a as $o) {
            $ns .= "\x81" . chr(strlen($o)) . $o;
        }
        return $ns;
    }

    // 返回数据
    function send($client, $msg)
    {
        $msg = $this->frame($msg);
        socket_write($client, $msg, strlen($msg));
    }
}

// 测试    
$ws = new WS("127.0.0.1",2000);