分享: 使用workerman实现基于UDP的异步SIP服务器，服务器端可主动发送UDP数据给客户端

自从使用workerman实现物联网终端接入以来，我工作中的所有网络场景（TCP\UDP\HTTP）等均使用workerman+channel以微服务方式实现，开发速度快，性能超级高。（几十万台设备同时接入都轻轻松松承受住）

之前多次关注过workerman的UDP服务器，但一没有实现我想要的结果
由于近期的业务需求，外加HTTP3 QUIC协议的广泛使用，workerman作为一个广泛使用的高性能PHP网络开发框架，支持持久化的UDP通信是很有必要的。

一直以来想通过workerman编写个基于UDP的SIP服务器和实现GB28181的国标协议，搭配SRS、ZLMediaKit或者monibuca，满足摄像头、硬盘录像机设备的接入，也可配合FreeSwitch实现基于SIP的语音通话或视频会议系统

workerman 主动发送udp数据
https://www.workerman.net/q/2688

UDP服务器主动向客户端发送消息
https://www.workerman.net/q/4284

直到今天终于使用workerman 实现单进程或多进程方式监听某个UDP端口，主动从平台向客户端发送数据
并且所有功能均使用workerman的loop功能，能够发挥平台最大化性能

当进程只有一个时使用 socket 函数实现端口监听，当进程大于1个时使用stream_socket实现端口监听（各有利弊，请酌情使用，大部分场景，推荐将进程数保持与CPU数量一致，自动使用 stream_socket ）

经过我初步测试：
当使用stream_socket时，服务器首次收到客户端发送的数据后，能够稳定的向客户端发送约5分钟的数据报文，直到该通信会话被Linux内核丢弃，因此使用UDP进行通信，建议至少60秒进行一次双向心跳交互保活。

当使用socket时，服务器首次收到客户端发送的数据后，能够稳定的向客户端长期发送数据报文（如果网络中的防火墙或NAT路由器没有将会话过期，应该可以一直使用）

下面直接发布代码

<?php
chdir(dirname($_SERVER['SCRIPT_FILENAME']));
include_once __DIR__ . '/vendor/autoload.php';

use Workerman\Worker;
use Workerman\Lib\Timer;

$worker = new Worker();
$worker->count = 1;   //开启进程数量
$processName = "sip_server_udp5060";
$worker->transport = "udp";
$worker->name = $processName;
$worker->reusePort = true;   //开启均衡负载模式

$date = date("Y-m-d");
Worker::$pidFile = "var/{$processName}.pid";
Worker::$logFile = "var/{$processName}_logFile.log";
Worker::$stdoutFile = "var/{$processName}_stdout.log";

$socket     = null;
$workerId   = null;

define("UNAUTHORIZED_KICKOFF_SECOND" ,  1);
define("UNAUTHORIZED_ALLOW_TRYTIME"  , 10);
define("UDP_SOCKET_TYPE_IS_STREAM"   ,  $worker->count > 1 ? 1 : 0 );

$worker->onWorkerStart = function() {
    global $worker , $workerId , $socket , $processName;

    //定期与数据库握手，避免被断掉，该动作每个进程都得执行

    $workerId = $worker->id ;
    $worker->connections = [];
    $worker->connections_ur = [];

    //根据daemon顺序延时，这是确保系统正常运行的关键
    usleep(1000 * 10 * ($worker->id+1) );

    echo date("Y-m-d H:i:s")." 服务进程{$worker->id}已经启动！\n";

    if( $workerId >= 0 ){

        //计划监听的UDP端口
        if(UDP_SOCKET_TYPE_IS_STREAM == 0){
            //这种模式只能运行一个进程
            $socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
            socket_bind($socket , "0.0.0.0" , 5060);
        }else{
            //这种模式可以多个进程共同监听同一端口
            $context = stream_context_create();
            $socket = stream_socket_server("udp://0.0.0.0:5060" , $error_code , $error_message , STREAM_SERVER_BIND , $context);
        }

        Worker::$globalEvent->add($socket, 1 , "acceptUdpConnection");   //加入全局事件loop

        /*
        //如果需要从服务器主动发数据给客户端，可以通过channel方式调用，具体的业务实现可以参照官方channel使用介绍

        Channel\Client::connect(CHANNEL_SIP_IP , CHANNEL_SIP_PORT);
        $event_name = $processName;    //UDP的数据回复跟TCP不一样，只要知道对方端口即可，理论上任意一个进程均可从服务器端发送数据给客户端
        //到公网环境查询本机公网IP，便于生成日志
        Channel\Client::on($event_name, function($event_data)use($worker , $event_name) {
        });
        */

        //每隔一段时间对长时间未进行通信的临时会话进行清理
        //不宜太大，太大容易遭受DDOS攻击，也不宜太小，太小的话有可能还没完成业务逻辑就被踢掉
        Timer::add( UNAUTHORIZED_KICKOFF_SECOND , function (){
            global $worker , $socket;
            $dateTime = date("Y-m-d H:i:s");
            $timeNow = time();

            foreach ($worker->connections_ur as $remote_address => $remote_arr){
                if( $remote_arr['lastMsgTime'] < $timeNow - UNAUTHORIZED_KICKOFF_SECOND ){
                    //非法接入，直接踢掉
                    unset($worker->connections_ur[$remote_address]);
                    //print("{$dateTime} {$remote_address} 踢掉非法接入\n");
                    //sendto($remote_address ,"illegal connection!\n");
                }

                //平台主动发送数据给终端，
                sendto($remote_address ,"{$dateTime} test send data!\n");
            }
        });

        //每隔一段时间对已经认证过的会话进行检查，对于长时间未通信的需要进行清理
        Timer::add( 60 , function (){
            global $worker , $socket;
            $dateTime = date("Y-m-d H:i:s");
            $timeNow = time();

            foreach ($worker->connections as $remote_address => $remote_arr){
                if( $remote_arr['lastMsgTime'] < $timeNow - 300 ){
                    //超时未通信，直接踢掉
                    unset($worker->connections[$remote_address]);
                    //这里编写远端会话离线的内容
                    //print("{$dateTime} {$remote_address} 会话超时掉线\n");
                    //sendto($remote_address ,"connection timeout!\n");
                }
            }
        });
    }
};

function sendto($remote_address , $send_buffer ){
    global $socket;
    if(UDP_SOCKET_TYPE_IS_STREAM == 0){
        list($host, $port) = explode(":" , $remote_address );
        socket_sendto($socket , $send_buffer , strlen($send_buffer), 0, $host, $port);
    }else{
        stream_socket_sendto( $socket, $send_buffer, 0, $remote_address);
    }
}

function acceptUdpConnection($socket){
    global $worker;
    $dateTime = date("Y-m-d H:i:s");
    $timeNow = time();

    set_error_handler(function(){});
    if(UDP_SOCKET_TYPE_IS_STREAM == 0){
        socket_recvfrom($socket, $recv_buffer, 65535, 0, $from, $port);
        $remote_address = "{$from}:{$port}";
    }else{
        $recv_buffer = stream_socket_recvfrom($socket, 65535 , 0, $remote_address);
    }

    restore_error_handler();
    if (false === $recv_buffer || empty($remote_address)) {
        return false;
    }

    if(
        isset($worker->connections[$remote_address]['lastMsgTime'])
        && $worker->connections[$remote_address]['lastMsgTime'] >= $timeNow - 300
    ){
        //已注册成功
        $worker->connections[$remote_address]['lastMsgTime'] = $timeNow;

        //处理业务逻辑  针对已经认证的合法连接
        //针对已经认证过的连接，建议将收到的数据通过channel发布到其他服务端进行轮询处理，以最大化提升系统处理性能，此时，本程序仅仅充当gateway功能

    }else{
        //未注册成功   未认证的可以进行几次通信
        $tryCount = $worker->connections_ur[$remote_address]['tryCount']??1;
        if( $tryCount < UNAUTHORIZED_ALLOW_TRYTIME ){
            $worker->connections_ur[$remote_address]['lastMsgTime'] = $timeNow;
            $worker->connections_ur[$remote_address]['tryCount'] = $tryCount + 1;
            //sendTo( $remote_address ,"{$dateTime} {$remote_address}:\nunauthorized,try time {$tryCount} \n");
            //处理业务逻辑   对于未认证的连接，必须在超时前完成认证       完成认证后需要将连接从  connections_ur 里面移出，并且加入到 connections 里面去
        }else{
            //超过一定交互次数但仍未完成认证的会话将被忽视，直到被踢下线
            //sendTo( $remote_address ,"{$dateTime} {$remote_address}:\nunauthorized,max try \n");
        }
    }

    //收到数据，打印日志
    print( "{$dateTime} {$remote_address}:\n{$recv_buffer}\n");
};

Worker::runAll();

/*
以下是程序输出样例数据

2024-03-27 01:15:52 39.129.72.95:50574:
REGISTER sip:34020000002000000001@3402000000 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.4:5060;rport;branch=z9hG4bK650883237
From: <sip:34020000001180870005@3402000000>;tag=698431213
To: <sip:34020000001180870005@3402000000>
Call-ID: 1146222786
CSeq: 1 REGISTER
Contact: <sip:34020000001180870005@192.168.1.4:5060>
Max-Forwards: 70
User-Agent: Embedded Net DVR/NVR/DVS
Expires: 86400
Content-Length: 0

2024-03-27 01:15:53 39.129.72.95:15363:
REGISTER sip:34020000002000000001@3402000000 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.2:5060;rport;branch=z9hG4bK1890963109
From: <sip:34020000001180870007@3402000000>;tag=1955740825
To: <sip:34020000001180870007@3402000000>
Call-ID: 254089720
CSeq: 1 REGISTER
Contact: <sip:34020000001180870007@192.168.1.2:5060>
Max-Forwards: 70
User-Agent: Embedded Net DVR/NVR/DVS
Expires: 86400
Content-Length: 0

2024-03-27 01:15:54 39.129.72.95:31137:
REGISTER sip:34020000002000000001@3402000000 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.8:5060;rport;branch=z9hG4bK1552460892
From: <sip:34020000001180870002@3402000000>;tag=1271059450
To: <sip:34020000001180870002@3402000000>
Call-ID: 108704431
CSeq: 1 REGISTER
Contact: <sip:34020000001180870002@192.168.1.8:5060>
Max-Forwards: 70
User-Agent: Embedded Net DVR/NVR/DVS
Expires: 86400
Content-Length: 0

01:38:09.293144 IP (tos 0x68, ttl 48, id 44466, offset 0, flags [DF], proto UDP (17), length 436)
    39.129.72.95.64959 > 192.168.27.21.5060: [udp sum ok] SIP, length: 408
        REGISTER sip:34020000002000000001@3402000000 SIP/2.0
        Via: SIP/2.0/UDP 192.168.1.7:5060;rport;branch=z9hG4bK1838031091
        From: <sip:34020000001180870003@3402000000>;tag=793428652
        To: <sip:34020000001180870003@3402000000>
        Call-ID: 1815643450
        CSeq: 1 REGISTER
        Contact: <sip:34020000001180870003@192.168.1.7:5060>
        Max-Forwards: 70
        User-Agent: Embedded Net DVR/NVR/DVS
        Expires: 86400
        Content-Length: 0

01:38:09.540771 IP (tos 0x0, ttl 64, id 30488, offset 0, flags [DF], proto UDP (17), length 64)
    192.168.27.21.5060 > 39.129.72.95.50574: [udp sum ok] SIP
01:38:09.540806 IP (tos 0x0, ttl 64, id 30489, offset 0, flags [DF], proto UDP (17), length 64)
    192.168.27.21.5060 > 39.129.72.95.31137: [udp sum ok] SIP
01:38:09.540815 IP (tos 0x0, ttl 64, id 30490, offset 0, flags [DF], proto UDP (17), length 64)
    192.168.27.21.5060 > 39.129.72.95.15363: [udp sum ok] SIP
01:38:09.540822 IP (tos 0x0, ttl 64, id 45413, offset 0, flags [DF], proto UDP (17), length 64)
    192.168.27.21.5060 > 39.130.87.71.34950: [udp sum ok] SIP
01:38:09.540830 IP (tos 0x0, ttl 64, id 27774, offset 0, flags [DF], proto UDP (17), length 64)
    192.168.27.21.5060 > 39.128.225.81.35329: [udp sum ok] SIP
01:38:09.540838 IP (tos 0x0, ttl 64, id 30491, offset 0, flags [DF], proto UDP (17), length 64)
    192.168.27.21.5060 > 39.129.72.95.26505: [udp sum ok] SIP
01:38:09.540845 IP (tos 0x0, ttl 64, id 2845, offset 0, flags [DF], proto UDP (17), length 64)
    192.168.27.21.5060 > 39.129.72.95.64959: [udp sum ok] SIP
01:38:09.540860 IP (tos 0x0, ttl 64, id 30493, offset 0, flags [DF], proto UDP (17), length 64)
    192.168.27.21.5060 > 39.129.72.95.36321: [udp sum ok] SIP
01:38:09.540867 IP (tos 0x0, ttl 64, id 27775, offset 0, flags [DF], proto UDP (17), length 64)
    192.168.27.21.5060 > 39.128.225.81.35342: [udp sum ok] SIP
01:38:09.540873 IP (tos 0x0, ttl 64, id 30494, offset 0, flags [DF], proto UDP (17), length 64)
    192.168.27.21.5060 > 39.129.72.95.23047: [udp sum ok] SIP
 * */