PayPal sends multiple IPN's - paypal

Question

I have this code, everything works fine. It's just that PayPal keeps resending multiple IPNs. I have read the forum of PayPal and they say that PayPal isn't getting a HTTP/1.1 200 OK from me, so it keeps resending the IPN. How would I go about this?
function sql_execute($sql){
$sql_connect = #mysql_connect($_SERVER['HTTP_HOST'].':3306','root', '****') or
die('Could not connect: ' . mysql_error());
mysql_select_db('4bkk');
mysql_query($sql);
$rows = mysql_affected_rows($sql_connect); //mysql_insert_id();
mysql_close();
return $rows;
}
function sql_query($sql){
// echo $sql;
$sql_connect = #mysql_connect($_SERVER['HTTP_HOST'].':3306','****', 'zzz111') or
die('Could not connect: ' . mysql_error());
mysql_select_db('4bkk');
$rs = mysql_query($sql) or die(mysql_error());
mysql_close();
return $rs;
}
function logtrace($o){
$q = "INSERT INTO log (trace, trace_time) VALUES ('$o', NOW() )";
sql_query($q);
}
function send_email($t,$s,$m,$h){
//mail($t, $s, $m, $h);
$fh = fopen('result_ipn_test.txt', 'w');
fwrite($fh, $t.' '.$s.' '.$m.' '.$h);
fclose($fh);
logtrace('Mail is sent and exit called');
exit();
}
logtrace('__________NEW SESSION__________');
$url = 'https://www.sandbox.paypal.com/cgi-bin/webscr';
$postFields = 'cmd=_notify-validate';
foreach($_POST as $key => $value)
{
$postFields .= "&$key=".urlencode($value);
}
$ch = curl_init();
curl_setopt_array($ch, array(
CURLOPT_URL => $url,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_SSL_VERIFYPEER => false,
CURLOPT_POST => true,
CURLOPT_POSTFIELDS => $postFields
));
$result = curl_exec($ch);
$info = curl_getinfo($ch);
logtrace($info['url']);
curl_close($ch);
//get buyers information from PAYPAL checkout
$email = $_POST['payer_email'];
$first_name = $_POST['first_name'];
$last_name = $_POST['last_name'];
$amount = $_POST['amount3'];
$plan = $_POST['option_selection1'];
logtrace($email.' -- '.$active);
$q = "SELECT * FROM users WHERE email='$email' AND user_level='' AND active='unverified'"; //Unprocessed record = no user_level and active = 'unverified'
$ex = sql_execute($q);
//logtrace("THIS ".$q." => ".$ex);
if(sql_execute($q)){
logtrace('IT IS TRUE');
$flag = TRUE;
}
else{
logtrace('FALSE');
$flag = FALSE;
}
logtrace($result.' RESPONSE FROM PAYPAL');
if(($result=='VERIFIED') && $flag){ //Checks first if PayPal is valid, email address exists in
//records and checks if user_level='' and active='unverified',
//if not enters.
logtrace('USER IS READY FOR VERIFICATION');
$q = "SELECT * FROM users WHERE email='$email'";
$data = sql_query($q);
$con = mysql_fetch_array($data);
//Get buyers information from the database
$email2 = $con['email'];
$first_name = $con['first_name'];
$last_name = $con['last_name'];
$active = $con['active'];
$user_level = $con['user_level'];
logtrace('Emails match');
$u = "UPDATE users SET active='verified', user_level='$plan' WHERE email='$email' LIMIT 1";
if (sql_query($u)) { //Successful verification
logtrace('|| Update was sucessful');
}
else{ // Unsuccessful verification.
logtrace('|| Something went wrong with update.');
}
}
else{ // The user doesn't have any record in the database.
$q = "SELECT * FROM users WHERE email='$email' AND (user_level='Monthly' OR user_level='Quarterly' OR user_level='Yearly')";
if(sql_execute($q)){ // The user is already verified
logtrace('THE USER IS ALREADY VERIFIED');
}
else{ // The user does not exist.
logtrace('THE USER HAS NO RECORD ON DATABASE');
}
}

Answer 1

Please refer the sample code https://www.x.com/instant-payment-notification-4
Based on the above code you can try setting curl options for
CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1
CURLOPT_HTTPHEADER, array('Connection: Close')
in your above code where you set as curl_setopt_array ...
This should resolve your HTTP/1.1 200 OK issue I think.