IP messenger using websockets - php

Question

I m trying to build an ip messenger for our college in php using websockets
with some success but when scaled to multiple users it failed .
It's throwing out the error that no socket resource was given in parameter for socket_select but that's not true .
also if somebody could properly explain the process of handshake in depth .thanking you in advance .Here's the code of the php server.
<?php
$host = ''//server ip;
echo $host;
$port = 9000;
if(!($sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP) )){
$errcode = socket_last_error();
$errormsg = socket_strerror($errcode);
die("couldn't create socket [$errcode]:$errormsg");
}
echo "successfully created the socket \n";
if(!socket_bind($sock, $host,$port)){
$errcode = socket_last_error();
$errormsg = socket_strerror($errcode);
die("couldn't bind socket to ip [$errcode]:$errormsg");
}
echo "successfully binded the socket to given ip\n";
if(!socket_listen($sock,10)){
$errcode = socket_last_error();
$errormsg = socket_strerror($errcode);
die("socket is deaf [$errcode]:$errormsg");
}
echo "socket started listening\n";
echo "waiting for incoming connections...\n";
$clients = array($sock);
$address_clients = array('127.0.0.1');
//start endless loop, so that our script doesn't stop
while (true) {
//manage multiple connections
$changed = $clients;
//returns the socket resources in $changed array
socket_select($changed, $null, $null, 0, 10);
//check for new socket
if (in_array($sock, $changed)) {
$socket_new = socket_accept($sock); //accept new socket
$clients[] = $socket_new; //add socket to client array
$found_socket = array_search($socket_new, $clients);
$header = socket_read($socket_new,1024); //read data sent by the socket
perform_handshaking($header, $socket_new, $host, $port); //perform websocket handshake
socket_getpeername($socket_new, $address,$port); //get ip address of connected socket
$address_clients[$found_socket] = $address;
echo "Client[$address] connected to us on port $port\n";
//make room for new socket
$found_socket = array_search($sock, $changed);
unset($changed[$found_socket]);
}
/*loop through all connected sockets*/
foreach($clients as $socketm){
//check for any incomming data
while(socket_recv($socketm, $buf, 1024, 0) >= 1)
{
$received_text = unmask($buf); //unmask data
$received = explode(',', $received_text);
echo $received[0]."\t".$received[1]."\n";
$found_socket = array_search($received[1], $address_clients);
echo $found_socket; //prepare data to be sent to client
socket_write($clients[$found_socket], mask($received[0]),strlen(mask($received[0])));
break 2; //exit this loop
}
$buf = #socket_read($socketm, 1024, PHP_NORMAL_READ);
if ($buf === false) { // check disconnected client
// remove client for $clients array
$found_socket = array_search($socketm, $clients);
socket_getpeername($socketm, $address);
unset($clients[$found_socket]);
echo "Client[$address] disconnected\n";
}
}
}
function perform_handshaking($receved_header,$client_conn, $host, $port)
{
$headers = array();
$lines = preg_split("/\r\n/", $receved_header);
foreach($lines as $line)
{
$line = chop($line);
if(preg_match('/\A(\S+): (.*)\z/', $line, $matches))
{
$headers[$matches[1]] = $matches[2];
}
}
$secKey = $headers['Sec-WebSocket-Key'];
$secAccept = base64_encode(pack('H*', sha1($secKey . '258EAFA5-E914-47DA-95CA-
C5AB0DC85B11')));
//hand shaking header
$upgrade = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" .
"Upgrade: websocket\r\n" .
"Connection: Upgrade\r\n" .
"WebSocket-Origin: $host\r\n" .
"WebSocket-Location: ws://$host:$port/\r\n".
"Sec-WebSocket-Accept:$secAccept\r\n\r\n";
socket_write($client_conn,$upgrade,strlen($upgrade));
return $upgrade;
}
function unmask($text) {
$length = ord($text[1]) & 127;
if($length == 126) {
$masks = substr($text, 4, 4);
$data = substr($text, 8);
}
elseif($length == 127) {
$masks = substr($text, 10, 4);
$data = substr($text, 14);
}
else {
$masks = substr($text, 2, 4);
$data = substr($text, 6);
}
$text = "";
for ($i = 0; $i < strlen($data); ++$i) {
$text .= $data[$i] ^ $masks[$i%4];
}
return $text;
}
//Encode message for transfer to client.
function mask($text)
{
$b1 = 0x80 | (0x1 & 0x0f);
$length = strlen($text);
if($length <= 125)
$header = pack('CC', $b1, $length);
elseif($length > 125 && $length < 65536)
$header = pack('CCn', $b1, 126, $length);
elseif($length >= 65536)
$header = pack('CCNN', $b1, 127, $length);
return $header.$text;
}
?>
I m actually trying to build a better and more useful social network than facebook(no adds ,no cookies).i am using websockets instead of traditional php,ajax,sql(long -polling ) which is much slower.any help will be greatly appreciated :)

Answer 1

Posting my answer if anybody in the future wants to work with websockets .I hope my answer will help them a lot saving a hard googling time .
<?php
$a = #$_SERVER['SERVER_ADDR'];
$host = $a;
$port = 9000;
if(!($sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP) )){
$errcode = socket_last_error();
$errormsg = socket_strerror($errcode);
die("couldn't create socket [$errcode]:$errormsg");
}
echo "successfully created the socket \n";
if(!socket_bind($sock, $host,$port)){
$errcode = socket_last_error();
$errormsg = socket_strerror($errcode);
die("couldn't bind socket to ip [$errcode]:$errormsg");
}
echo "successfully binded the socket to given ip\n";
if(!socket_listen($sock,10)){
$errcode = socket_last_error();
$errormsg = socket_strerror($errcode);
die("socket is deaf [$errcode]:$errormsg");
}
echo "socket started listening\n";
echo "waiting for incoming connections...\n";
$clients = array($sock);
$address_clients = array('127.0.0.1');
//start endless loop, so that our script doesn't stop
while (true) {
//manage multiple connections
$changed = $clients;
//returns the socket resources in $changed array
socket_select($changed, $null, $null, 0);
//check for new socket
if (in_array($sock, $changed)) {
$socket_new = socket_accept($sock); //accept new socket
$clients[] = $socket_new; //add socket to client array
$found_socket = array_search($socket_new, $clients);
$header = socket_read($socket_new,1024); //read data sent by the socket
perform_handshaking($header, $socket_new, $host, $port); //perform websocket handshake
socket_getpeername($socket_new, $address,$port); //get ip address of connected socket
$address_clients[$found_socket] = $address;
$found_socket = array_search($sock, $changed);
echo "Client[$address] connected to us on port $port\n";
//make room for new socket
unset($changed[$found_socket]);
for($i=1;$i<count($clients);$i++) {
$message = "Client[$address] connected to us on port $port\n";
socket_write($clients[$i], mask($message),strlen(mask($message)));
}
}
//loop through all connected sockets
foreach($changed as $changed_socket){
//check for any incomming data
while(socket_recv($changed_socket, $buf, 1024, 0) >= 1)
{
$received_text = unmask($buf); //unmask data
$received = explode(',', $received_text);
echo $received[0]."\t".$received[1]."\n";
$found_socket = array_search($received[1], $address_clients);
echo $found_socket; //prepare data to be sent to client
socket_write($clients[$found_socket], mask($received[0]),strlen(mask($received[0])));
break 2; //exit this loop
}
$buf = #socket_read($changed_socket, 1024, PHP_NORMAL_READ);
if ($buf === false) { // check disconnected client
// remove client for $clients array
$found_socket = array_search($changed_socket, $clients);
socket_getpeername($clients[$found_socket], $address);
unset($clients[$found_socket]);
echo "Client[$address] disconnected\n";
}
}
}
function perform_handshaking($receved_header,$client_conn, $host, $port)
{
$headers = array();
$lines = preg_split("/\r\n/", $receved_header);
foreach($lines as $line)
{
$line = chop($line);
if(preg_match('/\A(\S+): (.*)\z/', $line, $matches))
{
$headers[$matches[1]] = $matches[2];
}
}
$secKey = $headers['Sec-WebSocket-Key'];
$secAccept = base64_encode(pack('H*', sha1($secKey . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11')));
//hand shaking header
$upgrade = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" .
"Upgrade: websocket\r\n" .
"Connection: Upgrade\r\n" .
"WebSocket-Origin: $host\r\n" .
"WebSocket-Location: ws://$host:$port/\r\n".
"Sec-WebSocket-Accept:$secAccept\r\n\r\n";
socket_write($client_conn,$upgrade,strlen($upgrade));
return $upgrade;
}
function unmask($text) {
$length = ord($text[1]) & 127;
if($length == 126) {
$masks = substr($text, 4, 4);
$data = substr($text, 8);
}
elseif($length == 127) {
$masks = substr($text, 10, 4);
$data = substr($text, 14);
}
else {
$masks = substr($text, 2, 4);
$data = substr($text, 6);
}
$text = "";
for ($i = 0; $i < strlen($data); ++$i) {
$text .= $data[$i] ^ $masks[$i%4];
}
return $text;
}
//Encode message for transfer to client.
function mask($text)
{
$b1 = 0x80 | (0x1 & 0x0f);
$length = strlen($text);
if($length <= 125)
$header = pack('CC', $b1, $length);
elseif($length > 125 && $length < 65536)
$header = pack('CCn', $b1, 126, $length);
elseif($length >= 65536)
$header = pack('CCNN', $b1, 127, $length);
return $header.$text;
}
?>