can receive Data After sending through php Sockets - php

Question

i have a question about Sockets in PHP. My Environment Looks like follows:
one Server VM with Ubuntu 22.04 , and one VM with Windows 10. On The net is Global Cache IP2SL Adapter, on that interface is an Monitor with serial Line connected to this IP2SL.
The Goal should be , to send HEX Codes to the IP2SL which will be send to the Monitor. Some of These Codes have an Answer i.e. some Parameters like Brighness or Situation. In The end , on The Ubuntu is an Website where u can read and change those values . Therefore i've build some small testscripts to Check the Communication. To Monitor the line i use Wireshark, and both VM Linux and Windows run in a Parallels Environment on a Mac.
The Problem:
Did i send the hex code from windows to The IP2SL Adapter, anything looks fine, the command where send to the Monitor and the Monitor answer as expected. Did i send the same via php the command where send , and The Monitor Works with it as expected, if the commmand has no answer, i.e. PowerOn/Poweroff working like a charm, but if the Monitor should send an answer like brightness : XX% there come an "504 gateway TimeOut" After 60s on the Ubuntu System . did i do the same with IP2SL test App , the answer is correctly. In Wireshark is the Communication as expected. my php code Looks like follows
<?php
error_reporting(E_ALL);
ini_set('display_errors',1);
$port = '4999';
$adr = "192.168.100.34";
$sendStr = array('E5', 'TARGET', '20', '86');//hexadecimal data
$target = "05";
function makeValue($v)
{
return pack('H*',dechex($v));
}
function toSend($adr,$port,$target,$cmd)
{
ob_implicit_flush();
// find target
for($i=0;$i < count($cmd);$i++)
{
if($cmd[$i] === "TARGET")
{
$cmd[$i] = hexdec($target);
}
else
{
$cmd[$i] = hexdec($cmd[$i]);
}
}
// build the CRC
$cmd[] = hexdec('FF') - array_sum($cmd) & hexdec('FF');
//var_dump($cmd);
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
//socket_set_nonblock($socket);
if ($socket === false) {
echo "socket_create() fehlgeschlagen: Grund: " . socket_strerror(socket_last_error()) . "\n";
} else {
echo "Socket erstellt OK.\r\n";
}
echo "Versuche, zu '$adr' auf Port '$port' zu verbinden ...";
$result = socket_connect($socket, $adr, $port);
if ($result === false) {
echo "socket_connect() fehlgeschlagen.\nGrund: ($result) " . socket_strerror(socket_last_error($socket)) . "\n";
} else {
echo "Socket verbunden OK.\r\n";
}
$chars = array_map('makeValue',$cmd);
$out = join($chars);
$length = strlen($out);
//var_dump($out);
if(socket_write($socket, $out,$length))
{
usleep(25000);
$input = stream_get_contents($socket,1024);
socket_close($socket);
var_dump($input);
}
//socket_close($socket);
/*
if($input === FALSE || strcmp($input,'') == 0) {
$code = socket_last_error($socket);
socket_clear_error($socket);
socket_close($socket);
} else {
echo "Answer : ". bin2hex($input);
socket_close($socket);
}
*/
}
toSend($adr,$port,$target,$sendStr);
?>
Solution: The Solution is the array_map function 'makeValue'. The php pack command has an Format 'h*' and 'H*' , if the value is an Single Byte , the 'H*' converts it to the higher nibble , so the value '7' will Converted to '0x70'
function makeValue($v)
{
if(strlen($v)>1)
{
return pack('H*',dechex($v));
}
return pack('h*',dexhex($v));
}
this Solves the Problem