(PHP 4 >= 4.1.0, PHP 5)
socket_connect — Baut eine Verbindung über einen Socket auf
Baut über den gültigen Socket-Deskriptor socket, der von socket_create() zurückgegeben wurde, eine Verbindung zu address auf.
Der Parameter address ist entweder eine IPv4-Adresse in Punktnotation (z.B. 127.0.0.1), falls socket zur AF_INET-Familie gehört, oder eine gültige IPv6-Adresse (z.B ::1), falls die IPv6-Unterstützung aktiviert ist und socket zur AF_INET6-Familie gehört, oder der Pfadname eines Unix-Domain socket, falls der Socket zur AF_UNIX-Familie gehört.
Der Parameter port wird nur benutzt und ist dann zwingend erforderlich, wenn eine Verbindung zu einem AF_INET- oder einem AF_INET6-Socket aufgebaut wird. Er gibt an, zu welchem Port des entfernten Hosts eine Verbindung hergestellt werden soll.
Gibt bei Erfolg TRUE zurück. Im Fehlerfall wird FALSE zurückgegeben. Der Fehlercode kann mit der Funktion socket_last_error() ermittelt werden. Dieser Fehlercode kann an die Funktion socket_strerror() übergeben werden, um eine textuelle Beschreibung des Fehlers zu erhalten.
Hinweis:
Falls der Socket nicht blockiert ist, gibt diese Funktion FALSE sowie die Fehlermeldung Operation now in progress zurück.
This will give you a simple port-checker.
Note that on production-machines, you might want to alter the error reporting-level,
since unsuccessful connects will give you a "No connection could be made because
the target machine actively refused it"-error in the log.
Under Windows, make sure you enable the php_sockets.dll extension in your php.ini.
<?php
$address=$_SERVER['REMOTE_ADDR'];
if (isset($_REQUEST['port']) and
(!strlen($_REQUEST['port'])==0))
$port=$_REQUEST['port'];
else
unset($port);
if (isset($port) and
($socket=socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) and
(socket_connect($socket, $address, $port)))
{
$text="Connection successful on IP $address, port $port";
socket_close($socket);
}
else
$text="Unable to connect<pre>".socket_strerror(socket_last_error())."</pre>";
echo "<html><head></head><body>".
$text.
"</body></html>";
?>
Greetz,
Peter.
This will print the banner from a true 'telnet' server (router, switch, host, etc).
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
socket_connect($socket, '127.0.0.1', 23);
while (TRUE) {
$r = array($socket);
$c = socket_select($r, $w = NULL, $e = NULL, 5);
foreach ($r as $read_socket) {
if ($r = negotiate($read_socket)) {
var_dump($r);
exit;
}
}
}
function negotiate ($socket) {
socket_recv($socket, $buffer, 1024, 0);
for ($chr = 0; $chr < strlen($buffer); $chr++) {
if ($buffer[$chr] == chr(255)) {
$send = (isset($send) ? $send . $buffer[$chr] : $buffer[$chr]);
$chr++;
if (in_array($buffer[$chr], array(chr(251), chr(252)))) $send .= chr(254);
if (in_array($buffer[$chr], array(chr(253), chr(254)))) $send .= chr(252);
$chr++;
$send .= $buffer[$chr];
} else {
break;
}
}
if (isset($send)) socket_send($socket, $send, strlen($send), 0);
if ($chr - 1 < strlen($buffer)) return substr($buffer, $chr);
}
rbarnes' tip is helpful, but I found that I needed to add a check for SOCKET_EISCONN in the while loop:
...
$error = socket_last_error();
if ($error == SOCKET_EISCONN) {
$connected = true;
break;
}
...
At least on Mac OS X 10.5.
Hi there!
For the TCP connections: socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
In case you're having problems in socket_connect() with socket_strerror() = "Permission denied", you may be having a SELinux config issue.
Check if SELinux is enabled:
# /usr/sbin/sestatus -v
In case it is, you can just type the command:
# setsebool httpd_can_network_connect=1
That's it... I read you had to reboot, but I didn't and it worked fine anyway. More info, you may check:
http://arkiv.netbsd.se/?ml=squirrelmail-users&a=2005-11&t=1523021
Here is an example of a non-blocking connect which should perform quite a bit faster than the one posted by Seymour below:
<?php
function msConnectSocket($remote, $port, $timeout = 30) {
# this works whether $remote is a hostname or IP
$ip = "";
if( !preg_match('/^\d+\.\d+\.\d+\.\d+$/', $remote) ) {
$ip = gethostbyname($remote);
if ($ip == $remote) {
$this->errstr = "Error Connecting Socket: Unknown host";
return NULL;
}
} else $ip = $remote;
if (!($this->_SOCK = @socket_create(AF_INET, SOCK_STREAM, SOL_TCP))) {
$this->errstr = "Error Creating Socket: ".socket_strerror(socket_last_error());
return NULL;
}
socket_set_nonblock($this->_SOCK);
$error = NULL;
$attempts = 0;
$timeout *= 1000; // adjust because we sleeping in 1 millisecond increments
$connected;
while (!($connected = @socket_connect($this->_SOCK, $remote, $port+0)) && $attempts++ < $timeout) {
$error = socket_last_error();
if ($error != SOCKET_EINPROGRESS && $error != SOCKET_EALREADY) {
$this->errstr = "Error Connecting Socket: ".socket_strerror($error);
socket_close($this->_SOCK);
return NULL;
}
usleep(1000);
}
if (!$connected) {
$this->errstr = "Error Connecting Socket: Connect Timed Out After $timeout seconds. ".socket_strerror(socket_last_error());
socket_close($this->_SOCK);
return NULL;
}
socket_set_block($this->_SOCK);
return 1;
}
?>
This probably sounds like common sense, but it is something nobody i asked thought of... you can't bind the socket to localhost, you must bind it to either the IP your router assigns you, or your public IP address. If you bind to localhost, it will give an invalid resource error.
If you do want to have a socket_connect operation timeout you can use the following code.
<?php
$sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
socket_set_nonblock($sock);
socket_connect($sock,"127.0.0.1", 80);
socket_set_block($sock);
switch(socket_select($r = array($sock), $w = array($sock), $f = array($sock), 5))
{
case 2:
echo "[-] Connection Refused\n";
break;
case 1:
echo "[+] Connected\n";
break;
case 0:
echo "[-] Timeout\n";
break;
}
?>
This basically makes socket_connect return immediately then you can use socket_select to see how the socket reacted.
In reply to the function socket_raw_connect posted by "net_del at freemail dot ru". In the function you give a return value and afterwords you try to close the connection. That won't ever work. I think you want to alter your code ;-)
here's how you can implement timeouts with the socket functions.
this example works for blocking sockets but will work for both blocking and nonblocking with minor modifications. first call to connect in nonblocking mode returns 115 EINPROGRESS, additional calls return 114 EALREADY if the connection has not already failed or succeeded. once the connection succeeds, the socket resource will be returned.
<?
$host = "127.0.0.1";
$port = "80";
$timeout = 15; //timeout in seconds
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)
or die("Unable to create socket\n");
socket_set_nonblock($socket)
or die("Unable to set nonblock on socket\n");
$time = time();
while (!@socket_connect($socket, $host, $port))
{
$err = socket_last_error($socket);
if ($err == 115 || $err == 114)
{
if ((time() - $time) >= $timeout)
{
socket_close($socket);
die("Connection timed out.\n");
}
sleep(1);
continue;
}
die(socket_strerror($err) . "\n");
}
socket_set_block($this->socket)
or die("Unable to set block on socket\n");
?>
function socket_raw_connect ($server, $port, $timeout,$request)
{
if (!is_numeric($port) or !is_numeric($timeout)) {return false;}
$socket = fsockopen($server, $port, $errno, $errstr, $timeout);
fputs($socket, $request);
$ret = '';
while (!feof($socket))
{
$ret .= fgets($socket, 4096);
}
return $ret;
fclose($socket);
}
this code for easy raw connect.
Comment by net_del[nkg] (www.nkg.ru)
I am from russia. PHP is good language!
man page for connect :
EINPROGRESS
The socket is non-blocking and the connection cannot be completed immediately. It is possible to select(2) or poll(2) for completion by selecting the socket for writing. After select indicates writability, use getsockopt(2) to read the SO_ERROR option at level SOL_SOCKET to determine whether connect completed successfully (SO_ERROR is zero) or unsuccessfully (SO_ERROR is one of the usual error codes listed here, explaining the reason for the failure).
use socket_getoption($socket,SOL_SOCKET,SO_ERROR) . If you get value 115, it is connecting. If you get value different than 115 and 0, that means that an error has occured (see what error with socket_strerror()).
However, I don't know how does that works under Windows, maybe it wont work at all. It is supposed to work under Linux (man pages said that).
If you're using non-blocking, be sure not to turn it on until after you connect, otherwise you will get the mesasge:
PHP Warning: socket_connect() unable to connect [115]: Operation now in progress in file.php on line 123
and socket_connect() will return false (even though it will connect).
I had the same problem with the timeout, and i applied this solution.
It works only on linux PHP, i make a ping to the ip before connect the socket.....
<?php
$address = gethostbyname ($ip);
$command = "ping -c 1 " . $address;
$r = exec($command);
if ($r[0]=="r")
{
$socket = socket_create (AF_INET, SOCK_STREAM, 0);
if ($socket < 0) {
echo "socket_create() failed: reason: " . socket_strerror ($socket) . "\n";
} else {
echo "OK.\n";
}
?>