enrol/paypal/ipn.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Listens for Instant Payment Notification from PayPal
  19  *
  20  * This script waits for Payment notification from PayPal,
  21  * then double checks that data by sending it back to PayPal.
  22  * If PayPal verifies this then it sets up the enrolment for that
  23  * user.
  24  *
  25  * @package    enrol_paypal
  26  * @copyright 2010 Eugene Venter
  27  * @author     Eugene Venter - based on code by others
  28  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  29  */
  30
  31 // Disable moodle specific debug messages and any errors in output,
  32 // comment out when debugging or better look into error log!
  33 define('NO_DEBUG_DISPLAY', true);
  34
  35 require("../../config.php");
  36 require_once("lib.php");
  37 require_once($CFG->libdir.'/eventslib.php');
  38 require_once($CFG->libdir.'/enrollib.php');
  39 require_once($CFG->libdir . '/filelib.php');
  40
  41 // PayPal does not like when we return error messages here,
  42 // the custom handler just logs exceptions and stops.
  43 set_exception_handler('enrol_paypal_ipn_exception_handler');
  44
  45 /// Keep out casual intruders
  46 if (empty($_POST) or !empty($_GET)) {
  47     print_error("Sorry, you can not use the script that way.");
  48 }
  49
  50 /// Read all the data from PayPal and get it ready for later;
  51 /// we expect only valid UTF-8 encoding, it is the responsibility
  52 /// of user to set it up properly in PayPal business account,
  53 /// it is documented in docs wiki.
  54
  55 $req = 'cmd=_notify-validate';
  56
  57 $data = new stdClass();
  58
  59 foreach ($_POST as $key => $value) {
  60     $req .= "&$key=".urlencode($value);
  61     $data->$key = $value;
  62 }
  63
  64 $custom = explode('-', $data->custom);
  65 $data->userid           = (int)$custom[0];
  66 $data->courseid         = (int)$custom[1];
  67 $data->instanceid       = (int)$custom[2];
  68 $data->payment_gross    = $data->mc_gross;
  69 $data->payment_currency = $data->mc_currency;
  70 $data->timeupdated      = time();
  71
  72
  73 /// get the user and course records
  74
  75 if (! $user = $DB->get_record("user", array("id"=>$data->userid))) {
  76     message_paypal_error_to_admin("Not a valid user id", $data);
  77     die;
  78 }
  79
  80 if (! $course = $DB->get_record("course", array("id"=>$data->courseid))) {
  81     message_paypal_error_to_admin("Not a valid course id", $data);
  82     die;
  83 }
  84
  85 if (! $context = context_course::instance($course->id, IGNORE_MISSING)) {
  86     message_paypal_error_to_admin("Not a valid context id", $data);
  87     die;
  88 }
  89
  90 if (! $plugin_instance = $DB->get_record("enrol", array("id"=>$data->instanceid, "status"=>0))) {
  91     message_paypal_error_to_admin("Not a valid instance id", $data);
  92     die;
  93 }
  94
  95 $plugin = enrol_get_plugin('paypal');
  96
  97 /// Open a connection back to PayPal to validate the data
  98 $paypaladdr = empty($CFG->usepaypalsandbox) ? 'www.paypal.com' : 'www.sandbox.paypal.com';
  99 $c = new curl();
 100 $options = array(
 101     'returntransfer' => true,
 102     'httpheader' => array('application/x-www-form-urlencoded', "Host: $paypaladdr"),
 103     'timeout' => 30,
 104     'CURLOPT_HTTP_VERSION' => CURL_HTTP_VERSION_1_1,
 105 );
 106 $location = "https://$paypaladdr/cgi-bin/webscr";
 107 $result = $c->post($location, $req, $options);
 108
 109 if (!$result) {  /// Could not connect to PayPal - FAIL
 110     echo "<p>Error: could not access paypal.com</p>";
 111     message_paypal_error_to_admin("Could not access paypal.com to verify payment", $data);
 112     die;
 113 }
 114
 115 /// Connection is OK, so now we post the data to validate it
 116
 117 /// Now read the response and check if everything is OK.
 118
 119 if (strlen($result) > 0) {
 120     if (strcmp($result, "VERIFIED") == 0) {          // VALID PAYMENT!
 121
 122
 123         // check the payment_status and payment_reason
 124
 125         // If status is not completed or pending then unenrol the student if already enrolled
 126         // and notify admin
 127
 128         if ($data->payment_status != "Completed" and $data->payment_status != "Pending") {
 129             $plugin->unenrol_user($plugin_instance, $data->userid);
 130             message_paypal_error_to_admin("Status not completed or pending. User unenrolled from course", $data);
 131             die;
 132         }
 133
 134         // If currency is incorrectly set then someone maybe trying to cheat the system
 135
 136         if ($data->mc_currency != $plugin_instance->currency) {
 137             message_paypal_error_to_admin("Currency does not match course settings, received: ".$data->mc_currency, $data);
 138             die;
 139         }
 140
 141         // If status is pending and reason is other than echeck then we are on hold until further notice
 142         // Email user to let them know. Email admin.
 143
 144         if ($data->payment_status == "Pending" and $data->pending_reason != "echeck") {
 145             $eventdata = new stdClass();
 146             $eventdata->modulename        = 'moodle';
 147             $eventdata->component         = 'enrol_paypal';
 148             $eventdata->name              = 'paypal_enrolment';
 149             $eventdata->userfrom          = get_admin();
 150             $eventdata->userto            = $user;
 151             $eventdata->subject           = "Moodle: PayPal payment";
 152             $eventdata->fullmessage       = "Your PayPal payment is pending.";
 153             $eventdata->fullmessageformat = FORMAT_PLAIN;
 154             $eventdata->fullmessagehtml   = '';
 155             $eventdata->smallmessage      = '';
 156             message_send($eventdata);
 157
 158             message_paypal_error_to_admin("Payment pending", $data);
 159             die;
 160         }
 161
 162         // If our status is not completed or not pending on an echeck clearance then ignore and die
 163         // This check is redundant at present but may be useful if paypal extend the return codes in the future
 164
 165         if (! ( $data->payment_status == "Completed" or
 166                ($data->payment_status == "Pending" and $data->pending_reason == "echeck") ) ) {
 167             die;
 168         }
 169
 170         // At this point we only proceed with a status of completed or pending with a reason of echeck
 171
 172
 173
 174         if ($existing = $DB->get_record("enrol_paypal", array("txn_id"=>$data->txn_id))) {   // Make sure this transaction doesn't exist already
 175             message_paypal_error_to_admin("Transaction $data->txn_id is being repeated!", $data);
 176             die;
 177
 178         }
 179
 180         if (core_text::strtolower($data->business) !== core_text::strtolower($plugin->get_config('paypalbusiness'))) {   // Check that the email is the one we want it to be
 181             message_paypal_error_to_admin("Business email is {$data->business} (not ".
 182                     $plugin->get_config('paypalbusiness').")", $data);
 183             die;
 184
 185         }
 186
 187         if (!$user = $DB->get_record('user', array('id'=>$data->userid))) {   // Check that user exists
 188             message_paypal_error_to_admin("User $data->userid doesn't exist", $data);
 189             die;
 190         }
 191
 192         if (!$course = $DB->get_record('course', array('id'=>$data->courseid))) { // Check that course exists
 193             message_paypal_error_to_admin("Course $data->courseid doesn't exist", $data);
 194             die;
 195         }
 196
 197         $coursecontext = context_course::instance($course->id, IGNORE_MISSING);
 198
 199         // Check that amount paid is the correct amount
 200         if ( (float) $plugin_instance->cost <= 0 ) {
 201             $cost = (float) $plugin->get_config('cost');
 202         } else {
 203             $cost = (float) $plugin_instance->cost;
 204         }
 205
 206         // Use the same rounding of floats as on the enrol form.
 207         $cost = format_float($cost, 2, false);
 208
 209         if ($data->payment_gross < $cost) {
 210             message_paypal_error_to_admin("Amount paid is not enough ($data->payment_gross < $cost))", $data);
 211             die;
 212
 213         }
 214
 215         // ALL CLEAR !
 216
 217         $DB->insert_record("enrol_paypal", $data);
 218
 219         if ($plugin_instance->enrolperiod) {
 220             $timestart = time();
 221             $timeend   = $timestart + $plugin_instance->enrolperiod;
 222         } else {
 223             $timestart = 0;
 224             $timeend   = 0;
 225         }
 226
 227         // Enrol user
 228         $plugin->enrol_user($plugin_instance, $user->id, $plugin_instance->roleid, $timestart, $timeend);
 229
 230         // Pass $view=true to filter hidden caps if the user cannot see them
 231         if ($users = get_users_by_capability($context, 'moodle/course:update', 'u.*', 'u.id ASC',
 232                                              '', '', '', '', false, true)) {
 233             $users = sort_by_roleassignment_authority($users, $context);
 234             $teacher = array_shift($users);
 235         } else {
 236             $teacher = false;
 237         }
 238
 239         $mailstudents = $plugin->get_config('mailstudents');
 240         $mailteachers = $plugin->get_config('mailteachers');
 241         $mailadmins   = $plugin->get_config('mailadmins');
 242         $shortname = format_string($course->shortname, true, array('context' => $context));
 243
 244
 245         if (!empty($mailstudents)) {
 246             $a = new stdClass();
 247             $a->coursename = format_string($course->fullname, true, array('context' => $coursecontext));
 248             $a->profileurl = "$CFG->wwwroot/user/view.php?id=$user->id";
 249
 250             $eventdata = new stdClass();
 251             $eventdata->modulename        = 'moodle';
 252             $eventdata->component         = 'enrol_paypal';
 253             $eventdata->name              = 'paypal_enrolment';
 254             $eventdata->userfrom          = empty($teacher) ? get_admin() : $teacher;
 255             $eventdata->userto            = $user;
 256             $eventdata->subject           = get_string("enrolmentnew", 'enrol', $shortname);
 257             $eventdata->fullmessage       = get_string('welcometocoursetext', '', $a);
 258             $eventdata->fullmessageformat = FORMAT_PLAIN;
 259             $eventdata->fullmessagehtml   = '';
 260             $eventdata->smallmessage      = '';
 261             message_send($eventdata);
 262
 263         }
 264
 265         if (!empty($mailteachers) && !empty($teacher)) {
 266             $a->course = format_string($course->fullname, true, array('context' => $coursecontext));
 267             $a->user = fullname($user);
 268
 269             $eventdata = new stdClass();
 270             $eventdata->modulename        = 'moodle';
 271             $eventdata->component         = 'enrol_paypal';
 272             $eventdata->name              = 'paypal_enrolment';
 273             $eventdata->userfrom          = $user;
 274             $eventdata->userto            = $teacher;
 275             $eventdata->subject           = get_string("enrolmentnew", 'enrol', $shortname);
 276             $eventdata->fullmessage       = get_string('enrolmentnewuser', 'enrol', $a);
 277             $eventdata->fullmessageformat = FORMAT_PLAIN;
 278             $eventdata->fullmessagehtml   = '';
 279             $eventdata->smallmessage      = '';
 280             message_send($eventdata);
 281         }
 282
 283         if (!empty($mailadmins)) {
 284             $a->course = format_string($course->fullname, true, array('context' => $coursecontext));
 285             $a->user = fullname($user);
 286             $admins = get_admins();
 287             foreach ($admins as $admin) {
 288                 $eventdata = new stdClass();
 289                 $eventdata->modulename        = 'moodle';
 290                 $eventdata->component         = 'enrol_paypal';
 291                 $eventdata->name              = 'paypal_enrolment';
 292                 $eventdata->userfrom          = $user;
 293                 $eventdata->userto            = $admin;
 294                 $eventdata->subject           = get_string("enrolmentnew", 'enrol', $shortname);
 295                 $eventdata->fullmessage       = get_string('enrolmentnewuser', 'enrol', $a);
 296                 $eventdata->fullmessageformat = FORMAT_PLAIN;
 297                 $eventdata->fullmessagehtml   = '';
 298                 $eventdata->smallmessage      = '';
 299                 message_send($eventdata);
 300             }
 301         }
 302
 303     } else if (strcmp ($result, "INVALID") == 0) { // ERROR
 304         $DB->insert_record("enrol_paypal", $data, false);
 305         message_paypal_error_to_admin("Received an invalid payment notification!! (Fake payment?)", $data);
 306     }
 307 }
 308
 309 exit;
 310
 311
 312 //--- HELPER FUNCTIONS --------------------------------------------------------------------------------------
 313
 314
 315 function message_paypal_error_to_admin($subject, $data) {
 316     echo $subject;
 317     $admin = get_admin();
 318     $site = get_site();
 319
 320     $message = "$site->fullname:  Transaction failed.\n\n$subject\n\n";
 321
 322     foreach ($data as $key => $value) {
 323         $message .= "$key => $value\n";
 324     }
 325
 326     $eventdata = new stdClass();
 327     $eventdata->modulename        = 'moodle';
 328     $eventdata->component         = 'enrol_paypal';
 329     $eventdata->name              = 'paypal_enrolment';
 330     $eventdata->userfrom          = $admin;
 331     $eventdata->userto            = $admin;
 332     $eventdata->subject           = "PAYPAL ERROR: ".$subject;
 333     $eventdata->fullmessage       = $message;
 334     $eventdata->fullmessageformat = FORMAT_PLAIN;
 335     $eventdata->fullmessagehtml   = '';
 336     $eventdata->smallmessage      = '';
 337     message_send($eventdata);
 338 }
 339
 340 /**
 341  * Silent exception handler.
 342  *
 343  * @param Exception $ex
 344  * @return void - does not return. Terminates execution!
 345  */
 346 function enrol_paypal_ipn_exception_handler($ex) {
 347     $info = get_exception_info($ex);
 348
 349     $logerrmsg = "enrol_paypal IPN exception handler: ".$info->message;
 350     if (debugging('', DEBUG_NORMAL)) {
 351         $logerrmsg .= ' Debug: '.$info->debuginfo."\n".format_backtrace($info->backtrace, true);
 352     }
 353     error_log($logerrmsg);
 354
 355     exit(0);
 356 }