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, $context->id);
  97                 // force accessinfo refresh for users visiting this context...
  98                 mark_context_dirty($context->path);
  99                 email_paypal_error_to_admin("Status not completed or pending. User unenrolled from course", $data);
 100                 die;
 101             }
 102
 103             // If status is pending and reason is other than echeck then we are on hold until further notice
 104             // Email user to let them know. Email admin.
 105
 106             if ($data->payment_status == "Pending" and $data->pending_reason != "echeck") {
 107                 email_to_user($user, get_admin(), "Moodle: PayPal payment", "Your PayPal payment is pending.");
 108                 email_paypal_error_to_admin("Payment pending", $data);
 109                 die;
 110             }
 111
 112             // If our status is not completed or not pending on an echeck clearance then ignore and die
 113             // This check is redundant at present but may be useful if paypal extend the return codes in the future
 114
 115             if (! ( $data->payment_status == "Completed" or
 116                    ($data->payment_status == "Pending" and $data->pending_reason == "echeck") ) ) {
 117                 die;
 118             }
 119
 120             // At this point we only proceed with a status of completed or pending with a reason of echeck
 121
 122
 123
 124             if ($existing = get_record("enrol_paypal", "txn_id", addslashes($data->txn_id))) {   // Make sure this transaction doesn't exist already
 125                 email_paypal_error_to_admin("Transaction $data->txn_id is being repeated!", $data);
 126                 die;
 127
 128             }
 129
 130             if ($data->business != $CFG->enrol_paypalbusiness) {   // Check that the email is the one we want it to be
 131                 email_paypal_error_to_admin("Business email is $data->business (not $CFG->enrol_paypalbusiness)", $data);
 132                 die;
 133
 134             }
 135
 136             if (!$user = get_record('user', 'id', $data->userid)) {   // Check that user exists
 137                 email_paypal_error_to_admin("User $data->userid doesn't exist", $data);
 138                 die;
 139             }
 140
 141             if (!$course = get_record('course', 'id', $data->courseid)) { // Check that course exists
 142                 email_paypal_error_to_admin("Course $data->courseid doesn't exist", $data);;
 143                 die;
 144             }
 145
 146             // Check that amount paid is the correct amount
 147             if ( (float) $course->cost < 0 ) {
 148                 $cost = (float) $CFG->enrol_cost;
 149             } else {
 150                 $cost = (float) $course->cost;
 151             }
 152
 153             if ($data->payment_gross < $cost) {
 154                 $cost = format_float($cost, 2);
 155                 email_paypal_error_to_admin("Amount paid is not enough ($data->payment_gross < $cost))", $data);
 156                 die;
 157
 158             }
 159
 160             // ALL CLEAR !
 161
 162             if (!insert_record("enrol_paypal", addslashes_object($data))) {       // Insert a transaction record
 163                 email_paypal_error_to_admin("Error while trying to insert valid transaction", $data);
 164             }
 165
 166             if (!enrol_into_course($course, $user, 'paypal')) {
 167                 email_paypal_error_to_admin("Error while trying to enrol ".fullname($user)." in '$course->fullname'", $data);
 168                 die;
 169             } else {
 170                 $teacher = get_teacher($course->id);
 171
 172                 if (!empty($CFG->enrol_mailstudents)) {
 173                     $a->coursename = $course->fullname;
 174                     $a->profileurl = "$CFG->wwwroot/user/view.php?id=$user->id";
 175                     email_to_user($user, $teacher, get_string("enrolmentnew", '', $course->shortname),
 176                                   get_string('welcometocoursetext', '', $a));
 177                 }
 178
 179                 if (!empty($CFG->enrol_mailteachers)) {
 180                     $a->course = $course->fullname;
 181                     $a->user = fullname($user);
 182                     email_to_user($teacher, $user, get_string("enrolmentnew", '', $course->shortname),
 183                                   get_string('enrolmentnewuser', '', $a));
 184                 }
 185
 186                 if (!empty($CFG->enrol_mailadmins)) {
 187                     $a->course = $course->fullname;
 188                     $a->user = fullname($user);
 189                     $admins = get_admins();
 190                     foreach ($admins as $admin) {
 191                         email_to_user($admin, $user, get_string("enrolmentnew", '', $course->shortname),
 192                                       get_string('enrolmentnewuser', '', $a));
 193                     }
 194                 }
 195
 196             }
 197
 198
 199         } else if (strcmp ($result, "INVALID") == 0) { // ERROR
 200             insert_record("enrol_paypal", addslashes_object($data), false);
 201             email_paypal_error_to_admin("Received an invalid payment notification!! (Fake payment?)", $data);
 202         }
 203     }
 204
 205     fclose($fp);
 206     exit;
 207
 208
 209
 210 /// FUNCTIONS //////////////////////////////////////////////////////////////////
 211
 212
 213 function email_paypal_error_to_admin($subject, $data) {
 214     $admin = get_admin();
 215     $site = get_site();
 216
 217     $message = "$site->fullname:  Transaction failed.\n\n$subject\n\n";
 218
 219     foreach ($data as $key => $value) {
 220         $message .= "$key => $value\n";
 221     }
 222
 223     email_to_user($admin, $admin, "PAYPAL ERROR: ".$subject, $message);
 224
 225 }
 226
 227 ?>