php mqtt client

Posted 2020-08-09

<?php
 
/* phpMQTT */
class phpMQTT {
 
    private $socket;            /* holds the socket */
    private $msgid = 1;         /* counter for message id */
    public $keepalive = 10;     /* default keepalive timmer */
    public $timesinceping;      /* host unix time, used to detect disconects */
    public $topics = array();   /* used to store currently subscribed topics */
    public $debug = false;      /* should output debug messages */
    public $address;            /* broker address */
    public $port;               /* broker port */
    public $clientid;           /* client id sent to brocker */
    public $will;               /* stores the will of the client */
    private $username;          /* stores username */
    private $password;          /* stores password */
 
    function __construct($address, $port, $clientid){
        $this->broker($address, $port, $clientid);
    }
 
    /* sets the broker details */
    function broker($address, $port, $clientid){
        $this->address = $address;
        $this->port = $port;
        $this->clientid = $clientid;    
    }
 
    /* connects to the broker
        inputs: $clean: should the client send a clean session flag */
    function connect($clean = true, $will = NULL, $username = NULL, $password = NULL){
 
        if($will) $this->will = $will;
        if($username) $this->username = $username;
        if($password) $this->password = $password;
 
        $address = gethostbyname($this->address);   
        $this->socket = fsockopen($address, $this->port, $errno, $errstr, 60);
 
        if (!$this->socket ) {
            error_log("fsockopen() $errno, $errstr \n");
            return false;
        }
 
        stream_set_timeout($this->socket, 5);
        stream_set_blocking($this->socket, 0);
 
        $i = 0;
        $buffer = "";
 
        $buffer .= chr(0x00); $i++;
        $buffer .= chr(0x06); $i++;
        $buffer .= chr(0x4d); $i++;
        $buffer .= chr(0x51); $i++;
        $buffer .= chr(0x49); $i++;
        $buffer .= chr(0x73); $i++;
        $buffer .= chr(0x64); $i++;
        $buffer .= chr(0x70); $i++;
        $buffer .= chr(0x03); $i++;
 
        //No Will
        $var = 0;
        if($clean) $var+=2;
 
        //Add will info to header
        if($this->will != NULL){
            $var += 4; // Set will flag
            $var += ($this->will[‘qos‘] << 3); //Set will qos
            if($this->will[‘retain‘])    $var += 32; //Set will retain
        }
 
        if($this->username != NULL) $var += 128; //Add username to header
        if($this->password != NULL) $var += 64;  //Add password to header
 
        $buffer .= chr($var); $i++;
 
        //Keep alive
        $buffer .= chr($this->keepalive >> 8); $i++;
        $buffer .= chr($this->keepalive & 0xff); $i++;
 
        $buffer .= $this->strwritestring($this->clientid,$i);
 
        //Adding will to payload
        if($this->will != NULL){
            $buffer .= $this->strwritestring($this->will[‘topic‘],$i); 
            $buffer .= $this->strwritestring($this->will[‘content‘],$i);
        }
 
        if($this->username) $buffer .= $this->strwritestring($this->username,$i);
        if($this->password) $buffer .= $this->strwritestring($this->password,$i);
 
        $head = "  ";
        $head{0} = chr(0x10);
        $head{1} = chr($i);
 
        fwrite($this->socket, $head, 2);
        fwrite($this->socket,  $buffer);
 
        $string = $this->read(4);
 
        if(ord($string{0})>>4 == 2 && $string{3} == chr(0)){
            if($this->debug) echo "Connected to Broker\n";
        }else{ 
            error_log(sprintf("Connection failed! (Error: 0x%02x 0x%02x)\n",
                                    ord($string{0}),ord($string{3})));
            return false;
        }
 
        $this->timesinceping = time();
 
        return true;
    }
 
    /* read: reads in so many bytes */
    function read($int = 8192, $nb = false){
 
        //  print_r(socket_get_status($this->socket));
 
        $string="";
        $togo = $int;
 
        if($nb){
            return fread($this->socket, $togo);
        }
 
        while (!feof($this->socket) && $togo>0) {
            $fread = fread($this->socket, $togo);
            $string .= $fread;
            $togo = $int - strlen($string);
        }
 
            return $string;
    }
 
    /* subscribe: subscribes to topics */
    function subscribe($topics, $qos = 0){
        $i = 0;
        $buffer = "";
        $id = $this->msgid;
        $buffer .= chr($id >> 8);  $i++;
        $buffer .= chr($id % 256);  $i++;
 
        foreach($topics as $key => $topic){
            $buffer .= $this->strwritestring($key,$i);
            $buffer .= chr($topic["qos"]);  $i++;
            $this->topics[$key] = $topic;
        }
 
        $cmd = 0x80;
        //$qos
        $cmd += ($qos << 1);
 
        $head = chr($cmd);
        $head .= chr($i);
 
        fwrite($this->socket, $head, 2);
        fwrite($this->socket, $buffer, $i);
        $string = $this->read(2);
 
        $bytes = ord(substr($string,1,1));
        $string = $this->read($bytes);
    }
 
    /* ping: sends a keep alive ping */
    function ping(){
            $head = " ";
            $head = chr(0xc0);     
            $head .= chr(0x00);
            fwrite($this->socket, $head, 2);
            if($this->debug) echo "ping sent\n";
    }
 
    /* disconnect: sends a proper disconect cmd */
    function disconnect(){
            $head = " ";
            $head{0} = chr(0xe0);      
            $head{1} = chr(0x00);
            fwrite($this->socket, $head, 2);
    }
 
    /* close: sends a proper disconect, then closes the socket */
    function close(){
        $this->disconnect();
        fclose($this->socket);  
    }
 
    /* publish: publishes $content on a $topic */
    function publish($topic, $content, $qos = 0, $retain = 0){
 
        $i = 0;
        $buffer = "";
 
        $buffer .= $this->strwritestring($topic,$i);
 
        //$buffer .= $this->strwritestring($content,$i);
 
        if($qos){
            $id = $this->msgid++;
            $buffer .= chr($id >> 8);  $i++;
            $buffer .= chr($id % 256);  $i++;
        }
 
        $buffer .= $content;
        $i+=strlen($content);
 
        $head = " ";
        $cmd = 0x30;
        if($qos) $cmd += $qos << 1;
        if($retain) $cmd += 1;
 
        $head{0} = chr($cmd);      
        $head .= $this->setmsglength($i);
 
        fwrite($this->socket, $head, strlen($head));
        fwrite($this->socket, $buffer, $i);
 
    }
 
    /* message: processes a recieved topic */
    function message($msg){
            $tlen = (ord($msg{0})<<8) + ord($msg{1});
            $topic = substr($msg,2,$tlen);
            $msg = substr($msg,($tlen+2));
            $found = 0;
            foreach($this->topics as $key=>$top){
                if( preg_match("/^".str_replace("#",".*",
                        str_replace("+","[^\/]*",
                            str_replace("/","\/",
                                str_replace("$",‘\$‘,
                                    $key))))."$/",$topic) ){
                    if(function_exists($top[‘function‘])){
                        call_user_func($top[‘function‘],$topic,$msg);
                        $found = 1;
                    }
                }
            }
 
            if($this->debug && !$found) echo "msg recieved but no match in subscriptions\n";
    }
 
    /* proc: the processing loop for an "allways on" client
        set true when you are doing other stuff in the loop good for watching something else at the same time */   
    function proc( $loop = true){
 
        if(1){
            $sockets = array($this->socket);
            $w = $e = NULL;
            $cmd = 0;
 
                //$byte = fgetc($this->socket);
            if(feof($this->socket)){
                if($this->debug) echo "eof receive going to reconnect for good measure\n";
                fclose($this->socket);
                $this->connect(false);
                if(count($this->topics))
                    $this->subscribe($this->topics); 
            }
 
            $byte = $this->read(1, true);
 
            if(!strlen($byte)){
                if($loop){
                    usleep(100000);
                }
 
            }else{
 
                $cmd = (int)(ord($byte)/16);
                if($this->debug) echo "Recevid: $cmd\n";
 
                $multiplier = 1;
                $value = 0;
                do{
                    $digit = ord($this->read(1));
                    $value += ($digit & 127) * $multiplier;
                    $multiplier *= 128;
                    }while (($digit & 128) != 0);
 
                if($this->debug) echo "Fetching: $value\n";
 
                if($value)
                    $string = $this->read($value,"fetch");
 
                if($cmd){
                    switch($cmd){
                        case 3:
                            $this->message($string);
                        break;
                    }
 
                    $this->timesinceping = time();
                }
            }
 
            if($this->timesinceping < (time() - $this->keepalive )){
                if($this->debug) echo "not found something so ping\n";
                $this->ping();  
            }
 
            if($this->timesinceping<(time()-($this->keepalive*2))){
                if($this->debug) echo "not seen a package in a while, disconnecting\n";
                fclose($this->socket);
                $this->connect(false);
                if(count($this->topics))
                    $this->subscribe($this->topics);
            }
 
        }
        return 1;
    }
 
    /* getmsglength: */
    function getmsglength(&$msg, &$i){
 
        $multiplier = 1;
        $value = 0 ;
        do{
          $digit = ord($msg{$i});
          $value += ($digit & 127) * $multiplier;
          $multiplier *= 128;
          $i++;
        }while (($digit & 128) != 0);
 
        return $value;
    }
 
    /* setmsglength: */
    function setmsglength($len){
        $string = "";
        do{
          $digit = $len % 128;
          $len = $len >> 7;
          // if there are more digits to encode, set the top bit of this digit
          if ( $len > 0 )
            $digit = ($digit | 0x80);
          $string .= chr($digit);
        }while ( $len > 0 );
        return $string;
    }
 
    /* strwritestring: writes a string to a buffer */
    function strwritestring($str, &$i){
        $ret = " ";
        $len = strlen($str);
        $msb = $len >> 8;
        $lsb = $len % 256;
        $ret = chr($msb);
        $ret .= chr($lsb);
        $ret .= $str;
        $i += ($len+2);
        return $ret;
    }
 
    function printstr($string){
        $strlen = strlen($string);
            for($j=0;$j<$strlen;$j++){
                $num = ord($string{$j});
                if($num > 31)
                    $chr = $string{$j}; else $chr = " ";
                printf("%4d: %08b : 0x%02x : %s \n",$j,$num,$num,$chr);
            }
    }
}
 
?>

 

 publish.php

<?php
 
require("./phpMQTT.php");
 
$mqtt = new phpMQTT("localhost", 1883, "hacker");
 
if ($mqtt->connect()) {
    $mqtt->publish("hello","Hello World! at ".date("r"),0);
    $mqtt->close();
}
 
?>

 

 

subscribe.php

<?php
 
require("./phpMQTT.php");
 
$mqtt = new phpMQTT("localhost", 1883, "musikar");
 
if(!$mqtt->connect()){
    exit(1);
}
 
$topics[‘hello‘] = array("qos"=>0, "function"=>"procmsg");
$mqtt->subscribe($topics,0);
 
while($mqtt->proc()){
 
}
 
$mqtt->close();
 
function procmsg($topic,$msg){
        echo "Msg Recieved: ".date("r")."\nTopic:{$topic}\n$msg\n";
}
 
?>