socket_accept

Anonymous (2008-05-09 16:32:17)

If you want to know the remote address ( ip address ) and the port of an incoming connection that has been accepted with socket_accept(), you can use socket_getpeername()

Boylett (2008-04-18 09:01:29)

If you want to have multiple clients on a server you will have to use non blocking.

<?php

$clients = array();
$socket = socket_create(AF_INET,SOCK_STREAM,SOL_TCP);
socket_bind($socket,'127.0.0.1',$port);
socket_listen($socket);
socket_set_nonblock($socket);

while(true)
{
    if(($newc = socket_accept($socket)) !== false)
    {
        echo "Client $newc has connected\n";
        $clients[] = $newc;
    }
}

?>

lars at opdenkamp dot eu (2008-01-29 04:35:53)

If you want to make a daemon process that forks on each client connection, you'll find out that there's a bug in PHP. The child processes send SIGCHLD to their parent when they exit but the parent can't handle signals while it's waiting for socket_accept (blocking).

Here is a piece of code that makes a non-blocking forking server.

#!/usr/bin/php -q
<?php
/**
  * Listens for requests and forks on each connection
  */

$__server_listening = true;

error_reporting(E_ALL);
set_time_limit(0);
ob_implicit_flush();
declare(ticks = 1);

become_daemon();

/* nobody/nogroup, change to your host's uid/gid of the non-priv user */
change_identity(65534, 65534);

/* handle signals */
pcntl_signal(SIGTERM, 'sig_handler');
pcntl_signal(SIGINT, 'sig_handler');
pcntl_signal(SIGCHLD, 'sig_handler');

/* change this to your own host / port */
server_loop("127.0.0.1", 1234);

/**
  * Change the identity to a non-priv user
  */
function change_identity( $uid, $gid )
{
    if( !posix_setgid( $gid ) )
    {
        print "Unable to setgid to " . $gid . "!\n";
        exit;
    }

    if( !posix_setuid( $uid ) )
    {
        print "Unable to setuid to " . $uid . "!\n";
        exit;
    }
}

/**
  * Creates a server socket and listens for incoming client connections
  * @param string $address The address to listen on
  * @param int $port The port to listen on
  */
function server_loop($address, $port)
{
    GLOBAL $__server_listening;

    if(($sock = socket_create(AF_INET, SOCK_STREAM, 0)) < 0)
    {
        echo "failed to create socket: ".socket_strerror($sock)."\n";
        exit();
    }

    if(($ret = socket_bind($sock, $address, $port)) < 0)
    {
        echo "failed to bind socket: ".socket_strerror($ret)."\n";
        exit();
    }

    if( ( $ret = socket_listen( $sock, 0 ) ) < 0 )
    {
        echo "failed to listen to socket: ".socket_strerror($ret)."\n";
        exit();
    }

    socket_set_nonblock($sock);
    
    echo "waiting for clients to connect\n";

    while ($__server_listening)
    {
        $connection = @socket_accept($sock);
        if ($connection === false)
        {
            usleep(100);
        }elseif ($connection > 0)
        {
            handle_client($sock, $connection);
        }else
        {
            echo "error: ".socket_strerror($connection);
            die;
        }
    }
}

/**
  * Signal handler
  */
function sig_handler($sig)
{
    switch($sig)
    {
        case SIGTERM:
        case SIGINT:
            exit();
        break;

        case SIGCHLD:
            pcntl_waitpid(-1, $status);
        break;
    }
}

/** 
  * Handle a new client connection
  */
function handle_client($ssock, $csock)
{
    GLOBAL $__server_listening;

    $pid = pcntl_fork();

    if ($pid == -1)
    {
        /* fork failed */
        echo "fork failure!\n";
        die;
    }elseif ($pid == 0)
    {
        /* child process */
        $__server_listening = false;
        socket_close($ssock);
        interact($csock);
        socket_close($csock);
    }else
    {
        socket_close($csock);
    }
}

function interact($socket)
{
    /* TALK TO YOUR CLIENT */
}

/**
  * Become a daemon by forking and closing the parent
  */
function become_daemon()
{
    $pid = pcntl_fork();
    
    if ($pid == -1)
    {
        /* fork failed */
        echo "fork failure!\n";
        exit();
    }elseif ($pid)
    {
        /* close the parent */
        exit();
    }else
    {
        /* child becomes our daemon */
        posix_setsid();
        chdir('/');
        umask(0);
        return posix_getpid();

    }
}

?>

galantonp at yahoo dot com (2007-06-13 10:20:34)

socket_accept with timeout, seems to work for me on Apache/1.3.37 (FreeBSD 6.0) PHP/4.4.7. 

Adapted from ScriptBlue at nyc dot rr dot com's post under socket_connect.

<?php
$socket = socket_create(AF_INET,SOCK_STREAM,SOL_TCP);
socket_bind($socket,$address,$port);
socket_listen($socket);

echo "Waiting for a connection\n";
$conn = false;
switch(@socket_select($r = array($socket), $w = array($socket), $e = array($socket), 60)) {
    case 2:
        echo "Connection refused\n";
        break;
    case 1:
        echo "Connection accepted\n";
        $conn = @socket_accept($socket);
        break;
    case 0: 
        echo "Connection timed out\n";
        break;
}
    
    
if ($conn !== false) {
    // communicate over $conn
}

  
?>

gmkarl at gmail dot com (2007-05-22 09:15:16)

Be aware signal handler functions set with pcntl_signal are not called while a socket is blocking waiting for a connection; the signal is absorbed silently and the handler called when a connection is made.

simon at 180solutions dot com (2005-05-16 08:11:25)

>Accepting a connection using php-sockets:
>
>$fd = socket_create(AF_INET, SOCK_STREAM, 6 /* OR >getprotobyname("TCP")*/);
>
>$PORT = 5000;
>
>socket_bind($fd, "0.0.0.0", $PORT);
>
>while(true)
>{
>$remote_fd = socket_accept($fd);
>
>remote_socket_client_handle($remote_fd);
>
>}
>
>It is simple!
This example doesn't work. You have to call socket_listen($fd) after your bind in order to accept incoming connections.
Simon

Greg MacLellan (2003-12-11 12:49:14)

The socket returned by this resource will be non-blocking, regardless of what the listening socket is set to. This is actually true for all FCNTL modifiers.

diogo at transoft dot com dot br (2003-08-18 13:32:01)

Accepting a connection using php-sockets:
$fd = socket_create(AF_INET, SOCK_STREAM, 6 /* OR getprotobyname("TCP")*/);
$PORT = 5000;
socket_bind($fd, "0.0.0.0", $PORT);
while(true)
{
$remote_fd = socket_accept($fd);
remote_socket_client_handle($remote_fd);
}
It is simple!