enrol/paypal/ipn.php

   1 <?php  // $Id$
   2
   3 /**
   4 * Listens for Instant Payment Notification from PayPal
   5 *
   6 * This script waits for Payment notification from PayPal,
   7 * then double checks that data by sending it back to PayPal.
   8 * If PayPal verifies this then it sets up the enrolment for that
   9 *
  10 * Set the $user->timeaccess course array
  11 *
  12 * @param    user  referenced object, must contain $user->id already set
  13 */
  14
  15
  16     require("../../config.php");
  17     require("enrol.php");
  18
  19 /// Keep out casual intruders
  20     if (empty($_POST) or !empty($_GET)) {
  21         error("Sorry, you can not use the script that way.");
  22     }
  23
  24 /// Read all the data from PayPal and get it ready for later;
  25 /// we expect only valid UTF-8 encoding, it is the responsibility
  26 /// of user to set it up properly in PayPal business acount,
  27 /// it is documented in docs wiki.
  28
  29     $req = 'cmd=_notify-validate';
  30
  31     $data = new object();
  32
  33     foreach ($_POST as $key => $value) {
  34         $value = stripslashes($value);
  35         $req .= "&$key=".urlencode($value);
  36         $data->$key = $value;
  37     }
  38
  39     $custom = explode('-', $data->custom);
  40     $data->userid           = (int)$custom[0];
  41     $data->courseid         = (int)$custom[1];
  42     $data->payment_gross    = $data->mc_gross;
  43     $data->payment_currency = $data->mc_currency;
  44     $data->timeupdated      = time();
  45
  46
  47 /// get the user and course records
  48
  49     if (! $user = get_record("user", "id", $data->userid) ) {
  50         email_paypal_error_to_admin("Not a valid user id", $data);
  51         die;
  52     }
  53
  54     if (! $course = get_record("course", "id", $data->courseid) ) {
  55         email_paypal_error_to_admin("Not a valid course id", $data);
  56         die;
  57     }
  58
  59     if (! $context = get_context_instance(CONTEXT_COURSE, $course->id)) {
  60         email_paypal_error_to_admin("Not a valid context id", $data);
  61         die;
  62     }
  63
  64 /// Open a connection back to PayPal to validate the data
  65
  66     $header = '';
  67     $header .= "POST /cgi-bin/webscr HTTP/1.0\r\n";
  68     $header .= "Content-Type: application/x-www-form-urlencoded\r\n";
  69     $header .= "Content-Length: " . strlen($req) . "\r\n\r\n";
  70     $paypaladdr = empty($CFG->usepaypalsandbox) ? 'www.paypal.com' : 'www.sandbox.paypal.com';
  71     $fp = fsockopen ($paypaladdr, 80, $errno, $errstr, 30);
  72
  73     if (!$fp) {  /// Could not open a socket to PayPal - FAIL
  74         echo "<p>Error: could not access paypal.com</p>";
  75         email_paypal_error_to_admin("Could not access paypal.com to verify payment", $data);
  76         die;
  77     }
  78
  79 /// Connection is OK, so now we post the data to validate it
  80
  81     fputs ($fp, $header.$req);
  82
  83 /// Now read the response and check if everything is OK.
  84
  85     while (!feof($fp)) {
  86         $result = fgets($fp, 1024);
  87         if (strcmp($result, "VERIFIED") == 0) {          // VALID PAYMENT!
  88
  89
  90             // check the payment_status and payment_reason
  91
  92             // If status is not completed or pending then unenrol the student if already enrolled
  93             // and notify admin
  94
  95             if ($data->payment_status != "Completed" and $data->payment_status != "Pending") {
  96                 role_unassign(0, $data->userid, 0, $context->id);
  97                 email_paypal_error_to_admin("Status not completed or pending. User unenrolled from course", $data);
  98                 die;
  99             }
 100
 101             // If status is pending and reason is other than echeck then we are on hold until further notice
 102             // Email user to let them know. Email admin.
 103
 104             if ($data->payment_status == "Pending" and $data->pending_reason != "echeck") {
 105                 email_to_user($user, get_admin(), "Moodle: PayPal payment", "Your PayPal payment is pending.");
 106                 email_paypal_error_to_admin("Payment pending", $data);
 107                 die;
 108             }
 109
 110             // If our status is not completed or not pending on an echeck clearance then ignore and die
 111             // This check is redundant at present but may be useful if paypal extend the return codes in the future
 112
 113             if (! ( $data->payment_status == "Completed" or
 114                    ($data->payment_status == "Pending" and $data->pending_reason == "echeck") ) ) {
 115                 die;
 116             }
 117
 118             // At this point we only proceed with a status of completed or pending with a reason of echeck
 119
 120
 121
 122             if ($existing = get_record("enrol_paypal", "txn_id", addslashes($data->txn_id))) {   // Make sure this transaction doesn't exist already
 123                 email_paypal_error_to_admin("Transaction $data->txn_id is being repeated!", $data);
 124                 die;
 125
 126             }
 127
 128             if ($data->business != $CFG->enrol_paypalbusiness) {   // Check that the email is the one we want it to be
 129                 email_paypal_error_to_admin("Business email is $data->business (not $CFG->enrol_paypalbusiness)", $data);
 130                 die;
 131
 132             }
 133
 134             if (!$user = get_record('user', 'id', $data->userid)) {   // Check that user exists
 135                 email_paypal_error_to_admin("User $data->userid doesn't exist", $data);
 136                 die;
 137             }
 138
 139             if (!$course = get_record('course', 'id', $data->courseid)) { // Check that course exists
 140                 email_paypal_error_to_admin("Course $data->courseid doesn't exist", $data);;
 141                 die;
 142             }
 143
 144             // Check that amount paid is the correct amount
 145             if ( (float) $course->cost < 0 ) {
 146                 $cost = (float) $CFG->enrol_cost;
 147             } else {
 148                 $cost = (float) $course->cost;
 149             }
 150             $cost = format_float($cost, 2);
 151
 152             if ($data->payment_gross < $cost) {
 153                 email_paypal_error_to_admin("Amount paid is not enough ($data->payment_gross < $cost))", $data);
 154                 die;
 155
 156             }
 157
 158             // ALL CLEAR !
 159
 160             if (!insert_record("enrol_paypal", addslashes_object($data))) {       // Insert a transaction record
 161                 email_paypal_error_to_admin("Error while trying to insert valid transaction", $data);
 162             }
 163
 164             if (!enrol_into_course($course, $user, 'paypal')) {
 165                 email_paypal_error_to_admin("Error while trying to enrol ".fullname($user)." in '$course->fullname'", $data);
 166                 die;
 167             } else {
 168                 $teacher = get_teacher($course->id);
 169
 170                 if (!empty($CFG->enrol_mailstudents)) {
 171                     $a->coursename = $course->fullname;
 172                     $a->profileurl = "$CFG->wwwroot/user/view.php?id=$user->id";
 173                     email_to_user($user, $teacher, get_string("enrolmentnew", '', $course->shortname),
 174                                   get_string('welcometocoursetext', '', $a));
 175                 }
 176
 177                 if (!empty($CFG->enrol_mailteachers)) {
 178                     $a->course = $course->fullname;
 179                     $a->user = fullname($user);
 180                     email_to_user($teacher, $user, get_string("enrolmentnew", '', $course->shortname),
 181                                   get_string('enrolmentnewuser', '', $a));
 182                 }
 183
 184                 if (!empty($CFG->enrol_mailadmins)) {
 185                     $a->course = $course->fullname;
 186                     $a->user = fullname($user);
 187                     $admins = get_admins();
 188                     foreach ($admins as $admin) {
 189                         email_to_user($admin, $user, get_string("enrolmentnew", '', $course->shortname),
 190                                       get_string('enrolmentnewuser', '', $a));
 191                     }
 192                 }
 193
 194             }
 195
 196
 197         } else if (strcmp ($result, "INVALID") == 0) { // ERROR
 198             insert_record("enrol_paypal", addslashes_object($data), false);
 199             email_paypal_error_to_admin("Received an invalid payment notification!! (Fake payment?)", $data);
 200         }
 201     }
 202
 203     fclose($fp);
 204     exit;
 205
 206
 207
 208 /// FUNCTIONS //////////////////////////////////////////////////////////////////
 209
 210
 211 function email_paypal_error_to_admin($subject, $data) {
 212     $admin = get_admin();
 213     $site = get_site();
 214
 215     $message = "$site->fullname:  Transaction failed.\n\n$subject\n\n";
 216
 217     foreach ($data as $key => $value) {
 218         $message .= "$key => $value\n";
 219     }
 220
 221     email_to_user($admin, $admin, "PAYPAL ERROR: ".$subject, $message);
 222
 223 }
 224
 225 ?>