PayPal IPN sometimes not updating database - paypal

Question

For several weeks PayPal has not updated my database for some transactions. Maybe 3 out of 10 transactions are added to the database. Have no idea what's goin on. Before that, everything was fine. There are no errors, every single transaction in PayPal history is completed. I have no idea where the problem is.
Here's my ipn.php
<?php
if (gethostbyaddr($_SERVER['REMOTE_ADDR']) !== 'notify.paypal.com') {
exit();
}
// Require the functions to connect to database and fetch config values
require 'config.php';
require 'db.php';
// Fetch and sanitize POST and GET values
function getValue($value) {
return (!empty($value)) ? sanitize($value) : false;
}
function sanitize($data) {
return htmlentities(strip_tags(mysql_znote_escape_string($data)));
}
function VerifyPaypalIPN(array $IPN = null){
if(empty($IPN)){
$IPN = $_POST;
}
if(empty($IPN['verify_sign'])){
return null;
}
$IPN['cmd'] = '_notify-validate';
$PaypalHost = (empty($IPN['test_ipn']) ? 'www' : 'www.sandbox').'.paypal.com';
$cURL = curl_init();
curl_setopt($cURL, CURLOPT_SSL_VERIFYPEER, 1);
curl_setopt($cURL, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($cURL, CURLOPT_SSLVERSION, 6);
curl_setopt($cURL, CURLOPT_CAINFO, __DIR__ . '/cert/cacert.pem');
curl_setopt($cURL, CURLOPT_URL, "https://{$PaypalHost}/cgi-bin/webscr");
curl_setopt($cURL, CURLOPT_ENCODING, 'gzip');
curl_setopt($cURL, CURLOPT_BINARYTRANSFER, true);
curl_setopt($cURL, CURLOPT_POST, true); // POST back
curl_setopt($cURL, CURLOPT_POSTFIELDS, $IPN); // the $IPN
curl_setopt($cURL, CURLOPT_HEADER, false);
curl_setopt($cURL, CURLOPT_RETURNTRANSFER, true);
curl_setopt($cURL, CURLOPT_FORBID_REUSE, true);
curl_setopt($cURL, CURLOPT_FRESH_CONNECT, true);
curl_setopt($cURL, CURLOPT_CONNECTTIMEOUT, 30);
curl_setopt($cURL, CURLOPT_TIMEOUT, 60);
curl_setopt($cURL, CURLINFO_HEADER_OUT, true);
curl_setopt($cURL, CURLOPT_HTTPHEADER, array(
'Connection: close',
'Expect: ',
));
$Response = curl_exec($cURL);
$Status = (int)curl_getinfo($cURL, CURLINFO_HTTP_CODE);
curl_close($cURL);
if(empty($Response) or !preg_match('~^(VERIFIED|INVALID)$~i', $Response = trim($Response)) or !$Status){
return null;
}
if(intval($Status / 100) != 2){
return false;
}
return !strcasecmp($Response, 'VERIFIED');
}
// Fetch paypal configurations
$paypal = $config['paypal'];
$prices = $config['paypal_prices'];
// Send an empty HTTP 200 OK response to acknowledge receipt of the notification
header('HTTP/1.1 200 OK');
// Build the required acknowledgement message out of the notification just received
$req = 'cmd=_notify-validate';
foreach ($_POST as $key => $value) {
$value = urlencode(stripslashes($value));
$req .= "&$key=$value";
}
$postdata = $req;
// Assign payment notification values to local variables
$item_name = $_POST['item_name'];
$item_number = $_POST['item_number'];
$payment_status = $_POST['payment_status'];
$payment_amount = $_POST['mc_gross'];
$payment_currency = $_POST['mc_currency'];
$txn_id = getValue($_POST['txn_id']);
$receiver_email = getValue($_POST['receiver_email']);
$payer_email = getValue($_POST['payer_email']);
$custom = (int)$_POST['custom'];
$connectedIp = $_SERVER['REMOTE_ADDR'];
mysql_insert("INSERT INTO `paypal` VALUES ('0', '$txn_id', 'Connection from IP: $connectedIp', '0', '0', '0')");
$status = VerifyPaypalIPN();
if ($status) {
// Check that the payment_status is Completed
if ($payment_status == 'Completed') {
// Check that txn_id has not been previously processed
$txn_id_check = mysql_select_single("SELECT `txn_id` FROM `paypal` WHERE `txn_id`='$txn_id'");
if ($txn_id_check !== false) {
// Check that receiver_email is your Primary PayPal email
if ($receiver_email == $paypal['email']) {
$status = true;
$paidMoney = 0;
$paidPoints = 0;
foreach ($prices as $priceValue => $pointsValue) {
if ($priceValue == $payment_amount) {
$paidMoney = $priceValue;
$paidPoints = $pointsValue;
}
}
if ($paidMoney == 0) $status = false; // Wrong amount of money
if ($payment_currency != $paypal['currency']) $status = false; // Wrong currency
// Verify that the user haven't messed around with POST data
if ($status) {
// transaction log
mysql_insert("INSERT INTO `paypal` VALUES ('0', '$txn_id', '$payer_email', '$custom', '".$paidMoney."', '".$paidPoints."')");
// Process payment
$data = mysql_select_single("SELECT `premium_points` AS `old_points` FROM `accounts` WHERE `id`='$custom';");
// Give points to user
$new_points = $data['old_points'] + $paidPoints;
mysql_update("UPDATE `accounts` SET `premium_points`='$new_points' WHERE `id`='$custom'");
}
} else {
$pmail = $paypal['email'];
mysql_insert("INSERT INTO `paypal` VALUES ('0', '$txn_id', 'ERROR: Wrong mail. Received: $receiver_email, configured: $pmail', '0', '0', '0')");
}
}
}
} else {
// Something is wrong
mysql_insert("INSERT INTO `paypal` VALUES ('0', '$txn_id', 'ERROR: Invalid data. $postdata', '0', '0', '0')");
}
?>

Answer 1

You can review your account's IPN history at https://www.paypal.com/cgi-bin/webscr?cmd=_display-ipns-history
If you are receiving all the IPNs you expect, then you need to debug your listener. Add logging to determine where it's going wrong, such as not being able to do the post back to verify the IPN. Log everything to determine what the error is. Check your webserver logs as well.
Documentation regarding IPN is available at: https://developer.paypal.com/docs/api-basics/notifications/ipn/