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phpcodeigniterpaypalpaypal-ipn

Paypal IPN listener code hanging/not responding


I am using the 'textbook' IPN script example as found on the paypal website. However, when running this code via the IPN simulator, there is a huge loading time and then PayPal throws this error:

Proxy Error

The proxy server received an invalid response from an upstream server. The proxy server could not handle the request POST /webapps/developer/applications/ipn_simulator.

Reason: Error reading from remote server

Here is my IPN listener code.

Would much appreciate some help!

        // Send an empty HTTP 200 OK response to acknowledge receipt of the notification
        header('HTTP/1.1 200 OK');

        // 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           = $_POST['txn_id'];
        $receiver_email   = $_POST['receiver_email'];
        $payer_email      = $_POST['payer_email'];
        $job_id           = $_POST['custom'];

        // Build the required acknowledgement message out of the notification just received
        $req = 'cmd=_notify-validate';               // Add 'cmd=_notify-validate' to beginning of the acknowledgement

        foreach ($_POST as $key => $value) {         // Loop through the notification NV pairs
            $value = urlencode(stripslashes($value));  // Encode these values
            $req  .= "&$key=$value";                   // Add the NV pairs to the acknowledgement
        }

        // Set up the acknowledgement request headers
        $header  = "POST /cgi-bin/webscr HTTP/1.1\r\n";                    // HTTP POST request
        $header .= "Content-Type: application/x-www-form-urlencoded\r\n";
        $header .= "Content-Length: " . strlen($req) . "\r\n\r\n";

        // Open a socket for the acknowledgement request
        $fp = fsockopen('ssl://www.sandbox.paypal.com', 443, $errno, $errstr, 30);

        // Send the HTTP POST request back to PayPal for validation
        fputs($fp, $header . $req);

        while (!feof($fp)) {                     // While not EOF
            $res = fgets($fp, 1024);               // Get the acknowledgement response
            $message = 'fail';
            if (strcmp ($res, "VERIFIED") == 0) {  // Response contains VERIFIED - process notification


                // Possible processing steps for a payment include the following:

                $job = $this->jobmodel->get_by_id($job_id);

                // Process payment
                $this->jobmodel->add_payment($job_id, $_POST);
                $message = $job_id;

            }
            else if (strcmp ($res, "INVALID") == 0) {

                // Authentication protocol is complete - begin error handling

                $message = 'fail';

            }


            $filename = 'Paypal IPN' . date('d-m-Y g-i', mktime());
            $myFile = $_SERVER['DOCUMENT_ROOT']."/assets/html/paypal/$filename.html";
            $fh = fopen($myFile, 'w') or die("can't open file");
            fwrite($fh, $message);
            fclose($fh);

        }

        fclose($fp);  // Close the file

Solution

  • You're not sending a 'Host' header along in your IPN verification request, and your script doesn't appear to be able to handle HTTP chunked data.
    I would suggest starting with this example and working from there.

    <?php
    
    // CONFIG: Enable debug mode. This means we'll log requests into 'ipn.log' in the same directory.
    // Especially useful if you encounter network errors or other intermittent problems with IPN (validation).
    // Set this to 0 once you go live or don't require logging.
    define("DEBUG", 1);
    
    // Set to 0 once you're ready to go live
    define("USE_SANDBOX", 1);
    
    
    define("LOG_FILE", "./ipn.log");
    
    
    // Read POST data
    // reading posted data directly from $_POST causes serialization
    // issues with array data in POST. Reading raw POST data from input stream instead.
    $raw_post_data = file_get_contents('php://input');
    $raw_post_array = explode('&', $raw_post_data);
    $myPost = array();
    foreach ($raw_post_array as $keyval) {
        $keyval = explode ('=', $keyval);
        if (count($keyval) == 2)
            $myPost[$keyval[0]] = urldecode($keyval[1]);
    }
    // read the post from PayPal system and add 'cmd'
    $req = 'cmd=_notify-validate';
    if(function_exists('get_magic_quotes_gpc')) {
        $get_magic_quotes_exists = true;
    }
    foreach ($myPost as $key => $value) {
        if($get_magic_quotes_exists == true && get_magic_quotes_gpc() == 1) {
            $value = urlencode(stripslashes($value));
        } else {
            $value = urlencode($value);
        }
        $req .= "&$key=$value";
    }
    
    // Post IPN data back to PayPal to validate the IPN data is genuine
    // Without this step anyone can fake IPN data
    
    if(USE_SANDBOX == true) {
        $paypal_url = "https://www.sandbox.paypal.com/cgi-bin/webscr";
    } else {
        $paypal_url = "https://www.paypal.com/cgi-bin/webscr";
    }
    
    $ch = curl_init($paypal_url);
    if ($ch == FALSE) {
        return FALSE;
    }
    
    curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $req);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
    curl_setopt($ch, CURLOPT_FORBID_REUSE, 1);
    
    if(DEBUG == true) {
        curl_setopt($ch, CURLOPT_HEADER, 1);
        curl_setopt($ch, CURLINFO_HEADER_OUT, 1);
    }
    
    // CONFIG: Optional proxy configuration
    //curl_setopt($ch, CURLOPT_PROXY, $proxy);
    //curl_setopt($ch, CURLOPT_HTTPPROXYTUNNEL, 1);
    
    // Set TCP timeout to 30 seconds
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
    curl_setopt($ch, CURLOPT_HTTPHEADER, array('Connection: Close'));
    
    // CONFIG: Please download 'cacert.pem' from "http://curl.haxx.se/docs/caextract.html" and set the directory path
    // of the certificate as shown below. Ensure the file is readable by the webserver.
    // This is mandatory for some environments.
    
    //$cert = __DIR__ . "./cacert.pem";
    //curl_setopt($ch, CURLOPT_CAINFO, $cert);
    
    $res = curl_exec($ch);
    if (curl_errno($ch) != 0) // cURL error
        {
        if(DEBUG == true) { 
            error_log(date('[Y-m-d H:i e] '). "Can't connect to PayPal to validate IPN message: " . curl_error($ch) . PHP_EOL, 3, LOG_FILE);
        }
        curl_close($ch);
        exit;
    
    } else {
            // Log the entire HTTP response if debug is switched on.
            if(DEBUG == true) {
                error_log(date('[Y-m-d H:i e] '). "HTTP request of validation request:". curl_getinfo($ch, CURLINFO_HEADER_OUT) ." for IPN payload: $req" . PHP_EOL, 3, LOG_FILE);
                error_log(date('[Y-m-d H:i e] '). "HTTP response of validation request: $res" . PHP_EOL, 3, LOG_FILE);
    
                // Split response headers and payload
                list($headers, $res) = explode("\r\n\r\n", $res, 2);
            }
            curl_close($ch);
    }
    
    // Inspect IPN validation result and act accordingly
    
    if (strcmp ($res, "VERIFIED") == 0) {
        // check whether the payment_status is Completed
        // check that txn_id has not been previously processed
        // check that receiver_email is your PayPal email
        // check that payment_amount/payment_currency are correct
        // process payment and mark item as paid.
    
        // assign posted variables 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 = $_POST['txn_id'];
        //$receiver_email = $_POST['receiver_email'];
        //$payer_email = $_POST['payer_email'];
    
        if(DEBUG == true) {
            error_log(date('[Y-m-d H:i e] '). "Verified IPN: $req ". PHP_EOL, 3, LOG_FILE);
        }
    } else if (strcmp ($res, "INVALID") == 0) {
        // log for manual investigation
        // Add business logic here which deals with invalid IPN messages
        if(DEBUG == true) {
            error_log(date('[Y-m-d H:i e] '). "Invalid IPN: $req" . PHP_EOL, 3, LOG_FILE);
        }
    }
    
    ?>