Unable to capture response of PHP Sockets Connection :: 504 Gateway Time-out

Question

I am using the following php code to connect and send a request to a remote server through php sockets connection.

<?php 
$host    = "X.X.X.X";
$port    = 1234;
$message = "<request>test</request>";
echo "Message To server :".$message;
// create socket
$socket = socket_create(AF_INET, SOCK_STREAM, 0) or die("Could not create socket\n");
// connect to server
$result = socket_connect($socket, $host, $port) or die("Could not connect to server\n");  
// send string to server
socket_write($socket, $message, strlen($message)) or die("Could not send data to server\n");
// get server response
stream_set_timeout($socket, 10);
$result = socket_read ($socket, 1024) or die("Could not read server response\n");
//echo "Reply From Server  :".$result;
$info = stream_get_meta_data($socket);
if (isset($info['timed_out']) && $info['timed_out'])
{
    echo 'Connection timed out!';
}
else
{
    var_dump($result);
}
// close socket
socket_close($socket);
?>

As confirmed, the remote machine is receiving our request and sending appropriate response to us over the same session. But unfortunately, I am getting the following response when the script is executed -

504 Gateway Time-out. The server didn't respond in time.

When tried from Putty (same server from where the code was executed), I am getting the response almost instantly (in less than a second).

There is no firewall running that would block the responses. All VPN traffic passes through the tunnel without any blocks as seen in telnet request and response.

Now I am unable to figure out the exact reason of not getting the response through this php script. I had gone through many tutorials and sample codes but found no luck. :(

Members, please help.

Answer 1

I've worked with php socket that simulates a telnet session without setting a timeout parameter. Try the below and let me know how it well it goes

<?php

// You can use socket_strerror(socket_last_error()) to get the error details
$socket = socket_create(AF_INET,SOCK_STREAM,0) or die ('Could not create socket') ;

$result = socket_connect($socket,$host,$port) or die ('Could not connect to host');

// The server expects the enter key to pressed to execute the command which i simulate by
// appending a \n to the message sent to the server

socket_send($socket,$message,strlen($message),0) or die('Could not execute command');

$result = socket_read($socket,2048) or die('Could not read from socket');

var_dump($result);

Answer 2

This might be outdated, but a note on The PHP manual says:

In case anyone is puzzled, stream_set_timeout DOES NOT work for sockets created with socket_create or socket_accept. Use socket_set_option instead.

Instead of:

<?php
stream_set_timeout($socket,$sec,$usec);
?>

Use:

<?php
socket_set_option($socket, SOL_SOCKET, SO_RCVTIMEO, array('sec'=>$sec, 'usec'=>$usec));
socket_set_option($socket, SOL_SOCKET, SO_SNDTIMEO, array('sec'=>$sec, 'usec'=>$usec));
?>

Answer 3

Try setting the read mode in socket_read to PHP_NORMAL_READ