How to reject duplicate PHP socket connection from the same client? - php

Question

I want to reject duplicate socket connection when the same connected client try to connect again.
The below code I tried to store gamerId into an array then later check the array if new gamerId already exist or not. But seems the duplicate connection already made but I don't want to make any duplicate connection.
$address = '127.0.0.5';
$port = 8085;
$sock = socket_create(AF_INET, SOCK_STREAM, 0) or die('Not Created');
$bind = socket_bind($sock, $address, $port) or die("Not Binded");
$listen = socket_listen($sock, 1) or die("Didnot listen");
$accept = socket_accept($sock) or die("Not Accepted");
$readData = trim(socket_read($accept, 1024));
$gamerId = array();
$errHandler = array();
$gamerIdlen = count($gamerId);
function checkDuplicate($gamerId, $gamerIdLen, $readData, $errHandler)
{
for ($i = 0; $i < $gamerIdLen; $i++) {
if ($gamerId[$i] === $readData) {
return 1;
}
}
}
if (checkDuplicate($gamerId, $gamerIdlen, $readData, $errHandler) == 1) {
array_push($errHandler, "exist");
} else if (checkDuplicate($gamerId, $gamerIdlen, $readData, $errHandler) != 1) {
array_push($gamerId, $readData);
}
do {
global $accept;
$accept = socket_accept($sock) or die("Not Accepted");
print_r($errHandler);
print_r($gamerId);
} while (true);

Answer 1

Keep a map of sockets to identities and close a (new) socket after identifying, when an identity is already in the map.
$map = [
[socket1] => User(123),
[socket1] => User(124),
];

Answer 2

<?php
$address = '127.0.0.5';
$port = 8085;
$server = socket_create(AF_INET, SOCK_STREAM, 0) or die('Not Created');
socket_bind($server, $address, $port) or die("Not Binded");
socket_listen($server, 10) or die("Did not listen");
// clients before checking gamerId
$pending = [];
// accepted clients
$clients = [];
// gamerId list
$gamerIds = [];
// gamerId for socket
$clientsIds = new WeakMap();
echo "Listening...\n";
do {
// wait for new client and new data on sockets
$read = [$server, ...$pending, ...$clients];
$write = null;
$error = null;
if(socket_select($read, $write, $error)){
foreach($read as $socket){
if($socket === $server){
// new connection
$pending[] = socket_accept($server);
printf("New Socket connected\n");
} else if(in_array($socket, $pending, true)) {
// data for pending connection
$readData = socket_read($accept, 1024);
// remove key from pending
if (($key = array_search($socket, $pending, true)) !== false) {
array_splice($pending, $key, 1);
}
// client disconnected already
if($readData === false){
printf("Pending client disconnected #%d\n", (int)$socket);
socket_close($socket);
unset($socket);
continue;
}
// here should be something to extract gamerId (e.g. make sure it is X characters)
$readData = trim($readData);
if(in_array($readData, $gamerIds, true)){
printf("Pending client already connected #%d, blocked...\n", (int)$socket);
// close connection
socket_close($socket);
unset($socket);
} else {
printf("Pending client accepted #%d\n", (int)$socket);
// accept client
$clients[] = $socket;
$gamerIds[] = $readData;
$clientsIds[$socket] = $readData;
}
} else {
// client communication
$readData = socket_read($accept, 1024);
if($readData === false){
printf("Client disconnected #%d\n", (int)$socket);
// remove client
if (($key = array_search($socket, $clients, true)) !== false) {
array_splice($clients, $key, 1);
}
// remove gamerId from the list
if(isset($clientsIds[$socket])){
if (($key = array_search($clientsIds[$socket], $gamerIds, true)) !== false) {
array_splice($gamerIds, $key, 1);
}
}
socket_close($socket);
unset($socket);
} else {
// handle data...
printf("Data received from socket #%d\n", (int)$socket);
}
}
}
}
} while (true);