(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)
socket_create — Crée un socket
socket_create() crée un point de communication (une socket) et retourne une instance de Socket Une connexion typique réseau est composée de deux sockets : une qui joue le rôle de client et l'autre celui du serveur.
domain
Le paramètre domain spécifie la famille
de protocoles à utiliser par le socket.
| Domaine | Description |
|---|---|
AF_INET |
Protocole basé sur IPv4. TCP et UDP sont les protocoles communs de cette famille de protocoles. |
AF_INET6 |
Protocole basé sur IPv6. TCP et UDP sont les protocoles communs de cette famille de protocoles. Le support a été ajouté en PHP 5.0.0. |
AF_UNIX |
Famille de protocoles locales de communication. Le rendement
élevé et des moindres coûts supplémentaires lui font une
grande force d'IPC (Interprocess Communication).
|
type
Le paramètre type sélectionne le type de
communication à utiliser par le socket.
| Type | Description |
|---|---|
SOCK_STREAM |
Fournit des flux d'octets ordonnancés, fiables, full-duplex,
raccordés sur la base. Un mécanisme de transmission des données
"out-of-band" peut être supporté.
Le protocole TCP est basé sur ce type de sockets.
|
SOCK_DGRAM |
Support des datagrammes (moins de connexion, message non garanti d'une longueur maximum fixe). Le protocole UDP est basé sur ce type de sockets. |
SOCK_SEQPACKET |
Fournit un chemin de transmission de données séquentiel, fiable, connecté à la base par deux chemins pour les datagrammes de longueur maximale fixe ; un consommateur est requis pour lire la totalité d'un paquet avec chaque appel à la lecture. |
SOCK_RAW |
Fournit l'accès brut de protocole de réseau. Ce type spécial de socket peut être utilisé pour construire manuellement tout type de protocole. Une utilisation commune de ce type de sockets est le traitement des requêtes ICMP (comme le ping). |
SOCK_RDM |
Fournit une couche fiable de datagramme qui ne garantit pas l'ordre des données. Ce type de socket est le plus susceptible de ne pas être implémenté sur votre système d'exploitation. |
protocol
Le paramètre protocol définit le protocole
spécifique pour le domaine domain à utiliser
lors de communications sur un socket retourné. La valeur appropriée
peut être retrouvée par son nom en utilisant la fonction
getprotobyname(). Si le protocole désiré est TCP
ou UDP, les constantes correspondantes SOL_TCP
et SOL_UDP peuvent être utilisées.
| Nom | Description |
|---|---|
icmp |
Le protocole ICMP (Internet Control Message
Protocol) est utilisé tout d'abord par les
passerelles et les hôtes pour reporter les erreurs dans
des communications de datagramme. La commande
"ping" (présente dans les systèmes
de production modernes) est un exemple d'application
utilisant le protocole ICMP.
|
udp |
Le protocole UDP (User Datagramm Protocol)
est un protocole sans connexion, incertain avec les longueurs
d'enregistrements fixes. De ce fait, UDP
requiert une quantité minimum de protocole aérienne.
|
tcp |
Le protocole TCP (Transmission Control Protocol)
est un protocole fiable, connecté sur la base, orienté flux et
full-duplex. TCP garantit que chaque paquet est
reçu dans l'ordre dans lequel il a été envoyé. Si quelques paquets
sont perdus pendant la communication, TCP
retransmettra ces paquets tant que l'hôte destinataire ne les aura
pas reçu entièrement. Pour des raisons de fiabilité et de
performance, l'implémentation TCP, elle-même,
décide des frontières appropriées d'octets de la couche fondamentale
de communication du datagramme. Par conséquent, les applications
TCP doivent autoriser la possibilité de
transmission partielle d'enregistrements.
|
socket_create() retourne une instance de
Socket en cas de succès et false sinon.
Le code d'erreur généré peut être obtenu en appelant la fonction
socket_last_error(). Ce code d'erreur
peut être passé à la fonction socket_strerror()
pour obtenir un message d'erreur humainement lisible.
Si une valeur invalide est spécifiée au paramètre domain ou
au paramètre type, la fonction socket_create()
prendra comme paramètres par défaut respectivement AF_INET et
SOCK_STREAM et générera un message d'alerte
(E_WARNING).
| Version | Description |
|---|---|
| 8.0.0 | En cas de succès, cette fonction retourne désormais une instance de Socket ; auparavant, une resource était retournée. |
Took me about 20 minutes to figure out the proper arguments to supply for a AF_UNIX socket. Anything else, and I would get a PHP warning about the 'type' not being supported. I hope this saves someone else time.
<?php
$socket = socket_create(AF_UNIX, SOCK_STREAM, 0);
// code
?>It took some time to understand how one PHP process can communicate with another by means of unix udp sockets. Examples of 'server' and 'client' code are given below. Server is assumed to run before client starts.
'Server' code
<?php
if (!extension_loaded('sockets')) {
die('The sockets extension is not loaded.');
}
// create unix udp socket
$socket = socket_create(AF_UNIX, SOCK_DGRAM, 0);
if (!$socket)
die('Unable to create AF_UNIX socket');
// same socket will be used in recv_from and send_to
$server_side_sock = dirname(__FILE__)."/server.sock";
if (!socket_bind($socket, $server_side_sock))
die("Unable to bind to $server_side_sock");
while(1) // server never exits
{
// receive query
if (!socket_set_block($socket))
die('Unable to set blocking mode for socket');
$buf = '';
$from = '';
echo "Ready to receive...\n";
// will block to wait client query
$bytes_received = socket_recvfrom($socket, $buf, 65536, 0, $from);
if ($bytes_received == -1)
die('An error occured while receiving from the socket');
echo "Received $buf from $from\n";
$buf .= "->Response"; // process client query here
// send response
if (!socket_set_nonblock($socket))
die('Unable to set nonblocking mode for socket');
// client side socket filename is known from client request: $from
$len = strlen($buf);
$bytes_sent = socket_sendto($socket, $buf, $len, 0, $from);
if ($bytes_sent == -1)
die('An error occured while sending to the socket');
else if ($bytes_sent != $len)
die($bytes_sent . ' bytes have been sent instead of the ' . $len . ' bytes expected');
echo "Request processed\n";
}
?>
'Client' code
<?php
if (!extension_loaded('sockets')) {
die('The sockets extension is not loaded.');
}
// create unix udp socket
$socket = socket_create(AF_UNIX, SOCK_DGRAM, 0);
if (!$socket)
die('Unable to create AF_UNIX socket');
// same socket will be later used in recv_from
// no binding is required if you wish only send and never receive
$client_side_sock = dirname(__FILE__)."/client.sock";
if (!socket_bind($socket, $client_side_sock))
die("Unable to bind to $client_side_sock");
// use socket to send data
if (!socket_set_nonblock($socket))
die('Unable to set nonblocking mode for socket');
// server side socket filename is known apriori
$server_side_sock = dirname(__FILE__)."/server.sock";
$msg = "Message";
$len = strlen($msg);
// at this point 'server' process must be running and bound to receive from serv.sock
$bytes_sent = socket_sendto($socket, $msg, $len, 0, $server_side_sock);
if ($bytes_sent == -1)
die('An error occured while sending to the socket');
else if ($bytes_sent != $len)
die($bytes_sent . ' bytes have been sent instead of the ' . $len . ' bytes expected');
// use socket to receive data
if (!socket_set_block($socket))
die('Unable to set blocking mode for socket');
$buf = '';
$from = '';
// will block to wait server response
$bytes_received = socket_recvfrom($socket, $buf, 65536, 0, $from);
if ($bytes_received == -1)
die('An error occured while receiving from the socket');
echo "Received $buf from $from\n";
// close socket and delete own .sock file
socket_close($socket);
unlink($client_side_sock);
echo "Client exits\n";
?>Note that if you create a socket with AF_UNIX, a file will be created in the filesystem. This file is not removed when you call socket_close - you should unlink the file after you close the socket.Here is a ping function for PHP without using exec/system/passthrough/etc... Very useful to use to just test if a host is online before attempting to connect to it. Timeout is in seconds.
<?PHP
function ping($host, $timeout = 1) {
/* ICMP ping packet with a pre-calculated checksum */
$package = "\x08\x00\x7d\x4b\x00\x00\x00\x00PingHost";
$socket = socket_create(AF_INET, SOCK_RAW, 1);
socket_set_option($socket, SOL_SOCKET, SO_RCVTIMEO, array('sec' => $timeout, 'usec' => 0));
socket_connect($socket, $host, null);
$ts = microtime(true);
socket_send($socket, $package, strLen($package), 0);
if (socket_read($socket, 255))
$result = microtime(true) - $ts;
else $result = false;
socket_close($socket);
return $result;
}
?>I've written the ping() function using socket_create() with SOCK_RAW.
(on Unix System, you need to have the root acces to execute this function)
<?php
/// start ping.inc.php ///
$g_icmp_error = "No Error";
// timeout in ms
function ping($host, $timeout)
{
$port = 0;
$datasize = 64;
global $g_icmp_error;
$g_icmp_error = "No Error";
$ident = array(ord('J'), ord('C'));
$seq = array(rand(0, 255), rand(0, 255));
$packet = '';
$packet .= chr(8); // type = 8 : request
$packet .= chr(0); // code = 0
$packet .= chr(0); // checksum init
$packet .= chr(0); // checksum init
$packet .= chr($ident[0]); // identifier
$packet .= chr($ident[1]); // identifier
$packet .= chr($seq[0]); // seq
$packet .= chr($seq[1]); // seq
for ($i = 0; $i < $datasize; $i++)
$packet .= chr(0);
$chk = icmpChecksum($packet);
$packet[2] = $chk[0]; // checksum init
$packet[3] = $chk[1]; // checksum init
$sock = socket_create(AF_INET, SOCK_RAW, getprotobyname('icmp'));
$time_start = microtime();
socket_sendto($sock, $packet, strlen($packet), 0, $host, $port);
$read = array($sock);
$write = NULL;
$except = NULL;
$select = socket_select($read, $write, $except, 0, $timeout * 1000);
if ($select === NULL)
{
$g_icmp_error = "Select Error";
socket_close($sock);
return -1;
}
elseif ($select === 0)
{
$g_icmp_error = "Timeout";
socket_close($sock);
return -1;
}
$recv = '';
$time_stop = microtime();
socket_recvfrom($sock, $recv, 65535, 0, $host, $port);
$recv = unpack('C*', $recv);
if ($recv[10] !== 1) // ICMP proto = 1
{
$g_icmp_error = "Not ICMP packet";
socket_close($sock);
return -1;
}
if ($recv[21] !== 0) // ICMP response = 0
{
$g_icmp_error = "Not ICMP response";
socket_close($sock);
return -1;
}
if ($ident[0] !== $recv[25] || $ident[1] !== $recv[26])
{
$g_icmp_error = "Bad identification number";
socket_close($sock);
return -1;
}
if ($seq[0] !== $recv[27] || $seq[1] !== $recv[28])
{
$g_icmp_error = "Bad sequence number";
socket_close($sock);
return -1;
}
$ms = ($time_stop - $time_start) * 1000;
if ($ms < 0)
{
$g_icmp_error = "Response too long";
$ms = -1;
}
socket_close($sock);
return $ms;
}
function icmpChecksum($data)
{
$bit = unpack('n*', $data);
$sum = array_sum($bit);
if (strlen($data) % 2) {
$temp = unpack('C*', $data[strlen($data) - 1]);
$sum += $temp[1];
}
$sum = ($sum >> 16) + ($sum & 0xffff);
$sum += ($sum >> 16);
return pack('n*', ~$sum);
}
function getLastIcmpError()
{
global $g_icmp_error;
return $g_icmp_error;
}
/// end ping.inc.php ///
?>On UNIX systems php needs /etc/protocols for constants like SOL_UDP and SOL_TCP.
This file was missing on my embedded platform.Please be aware that RAW sockets (as used for the ping example) are restricted to root accounts on *nix systems. Since web servers hardly ever run as root, they won't work on webpages.
On Windows based servers it should work regardless.Okay I talked with Richard a little (via e-mail). We agree that getprotobyname() and using the constants should be the same in functionality and speed, the use of one or the other is merely coding style. Personally, we both think the constants are prettier :).
The eight different protocols are the ones implemented in PHP- not the total number in existance (RFC 1340 has 98).
All we disagree on is using 0- Richard says that "accordning to the official unix/bsd sockets 0 is more than fine." I think that since 0 is a reserved number according to RFC 1320, and when used usually refers to IP, not one of it's sub-protocols (TCP, UDP, etc.)Here's a ping function that uses sockets instead of exec(). Note: I was unable to get socket_create() to work without running from CLI as root. I've already calculated the package's checksum to simplify the code (the message is 'ping' but it doesn't actually matter).
<?php
function ping($host) {
$package = "\x08\x00\x19\x2f\x00\x00\x00\x00\x70\x69\x6e\x67";
/* create the socket, the last '1' denotes ICMP */
$socket = socket_create(AF_INET, SOCK_RAW, 1);
/* set socket receive timeout to 1 second */
socket_set_option($socket, SOL_SOCKET, SO_RCVTIMEO, array("sec" => 1, "usec" => 0));
/* connect to socket */
socket_connect($socket, $host, null);
/* record start time */
list($start_usec, $start_sec) = explode(" ", microtime());
$start_time = ((float) $start_usec + (float) $start_sec);
socket_send($socket, $package, strlen($package), 0);
if(@socket_read($socket, 255)) {
list($end_usec, $end_sec) = explode(" ", microtime());
$end_time = ((float) $end_usec + (float) $end_sec);
$total_time = $end_time - $start_time;
return $total_time;
} else {
return false;
}
socket_close($socket);
}
?>Seems there aren't any examples of UDP clients out there. This is a tftp client. I hope this makes someone's life easier.
<?php
function tftp_fetch($host, $filename)
{
$socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
// create the request packet
$packet = chr(0) . chr(1) . $filename . chr(0) . 'octet' . chr(0);
// UDP is connectionless, so we just send on it.
socket_sendto($socket, $packet, strlen($packet), 0x100, $host, 69);
$buffer = '';
$port = '';
$ret = '';
do
{
// $buffer and $port both come back with information for the ack
// 516 = 4 bytes for the header + 512 bytes of data
socket_recvfrom($socket, $buffer, 516, 0, $host, $port);
// add the block number from the data packet to the ack packet
$packet = chr(0) . chr(4) . substr($buffer, 2, 2);
// send ack
socket_sendto($socket, $packet, strlen($packet), 0, $host, $port);
// append the data to the return variable
// for large files this function should take a file handle as an arg
$ret .= substr($buffer, 4);
}
while(strlen($buffer) == 516); // the first non-full packet is the last.
return $ret;
}
?>Sometimes when you are running CLI, you need to know your own ip address.
<?php
$addr = my_ip();
echo "my ip address is $addr\n";
function my_ip($dest='64.0.0.0', $port=80)
{
$socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
socket_connect($socket, $dest, $port);
socket_getsockname($socket, $addr, $port);
socket_close($socket);
return $addr;
}
?>Here's a solution for icmpv6 ping with php, dropping it here in case if someone has problems with icmpv6 with php.
<?php
$host = "2a03:2880:f11b:83:face:b00c:0:25de";
$timeout = 100000;
$count = 3;
echo "Latency: ". round(1000 * pingv6($host,$timeout,$count),5) ." ms \n";
function pingv6($target,$timeout,$count) {
echo "target is ipv6 address, ". getprotobyname('ipv6-icmp'). " \n";
/* create the socket, the last '1' denotes ICMP */
$socket = socket_create(AF_INET6, SOCK_RAW, getprotobyname('ipv6-icmp'));
/* set socket receive timeout to 1 second */
$sec=intval($timeout/1000);
$usec=$timeout%1000*1000;
socket_set_option($socket, SOL_SOCKET, SO_RCVTIMEO, array("sec"=>$sec, "usec"=>$usec));
/* socket package parameters */
$type = "\x80";
$seqNumber = chr(floor($i/256)%256) . chr($i%256);
$checksum= "\x00\x00";
$code = "\x00";
$identifier = chr(rand(0,255)) . chr(rand(0,255));
$msg = "!\"#$%&'()*+,-./1234567";
$package = $type.$code.$checksum.$identifier.$seqNumber.$msg;
$checksum = icmpChecksum($package);
$package = $type.$code.$checksum.$identifier.$seqNumber.$msg;
/* socket connect */
if(@socket_connect($socket, $target, null)){
for($i = 0; $i < $count; $i++){
list($start_usec, $start_sec) = explode(" ", microtime());
$start_time = ((float) $start_usec + (float) $start_sec);
$startTime = microtime(true);
socket_send($socket, $package, strLen($package), 0);
while ($startTime + $timeout*1000 > microtime(true)){
if(socket_read($socket, 255) !== false) {
list($end_usec, $end_sec) = explode(" ", microtime());
$end_time = ((float) $end_usec + (float) $end_sec);
$total_time = $end_time - $start_time;
echo "round trip time (".$i."): ". $total_time ."\n";
return $total_time;
break;
}else{
return "null";
echo "Timed out (".$i."), Got no echo reply\n";
break;
}
}
usleep($interval*1000);
}
socket_close($socket);
}
}
function icmpChecksum($data){
if (strlen($data)%2) $data .= "\x00";
$bit = unpack('n*', $data);
$sum = array_sum($bit);
while ($sum >> 16)
$sum = ($sum >> 16) + ($sum & 0xffff);
return pack('n*', ~$sum);
}
?>