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<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Web services utility functions and classes
*
* @package webservice
* @copyright 2009 Moodle Pty Ltd (http://moodle.com)
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
require_once($CFG->libdir.'/externallib.php');
define('WEBSERVICE_AUTHMETHOD_USERNAME', 0);
define('WEBSERVICE_AUTHMETHOD_PERMANENT_TOKEN', 1);
define('WEBSERVICE_AUTHMETHOD_SESSION_TOKEN', 2);
/**
* General web service library
*/
class webservice {
/**
* Add a user to the list of authorised user of a given service
* @param object $user
*/
public function add_ws_authorised_user($user) {
global $DB;
$user->timecreated = mktime();
$DB->insert_record('external_services_users', $user);
}
/**
* Remove a user from a list of allowed user of a service
* @param object $user
* @param int $serviceid
*/
public function remove_ws_authorised_user($user, $serviceid) {
global $DB;
$DB->delete_records('external_services_users',
array('externalserviceid' => $serviceid, 'userid' => $user->id));
}
/**
* Update service allowed user settings
* @param object $user
*/
public function update_ws_authorised_user($user) {
global $DB;
$DB->update_record('external_services_users', $user);
}
/**
* Return list of allowed users with their options (ip/timecreated / validuntil...)
* for a given service
* @param int $serviceid
* @return array $users
*/
public function get_ws_authorised_users($serviceid) {
global $DB, $CFG;
$params = array($CFG->siteguest, $serviceid);
$sql = " SELECT u.id as id, esu.id as serviceuserid, u.email as email, u.firstname as firstname,
u.lastname as lastname,
esu.iprestriction as iprestriction, esu.validuntil as validuntil,
esu.timecreated as timecreated
FROM {user} u, {external_services_users} esu
WHERE u.id <> ? AND u.deleted = 0 AND u.confirmed = 1
AND esu.userid = u.id
AND esu.externalserviceid = ?";
$users = $DB->get_records_sql($sql, $params);
return $users;
}
/**
* Return a authorised user with his options (ip/timecreated / validuntil...)
* @param int $serviceid
* @param int $userid
* @return object
*/
public function get_ws_authorised_user($serviceid, $userid) {
global $DB, $CFG;
$params = array($CFG->siteguest, $serviceid, $userid);
$sql = " SELECT u.id as id, esu.id as serviceuserid, u.email as email, u.firstname as firstname,
u.lastname as lastname,
esu.iprestriction as iprestriction, esu.validuntil as validuntil,
esu.timecreated as timecreated
FROM {user} u, {external_services_users} esu
WHERE u.id <> ? AND u.deleted = 0 AND u.confirmed = 1
AND esu.userid = u.id
AND esu.externalserviceid = ?
AND u.id = ?";
$user = $DB->get_record_sql($sql, $params);
return $user;
}
/**
* Generate all ws token needed by a user
* @param int $userid
*/
public function generate_user_ws_tokens($userid) {
global $CFG, $DB;
/// generate a token for non admin if web service are enable and the user has the capability to create a token
if (!is_siteadmin() && has_capability('moodle/webservice:createtoken', get_context_instance(CONTEXT_SYSTEM), $userid) && !empty($CFG->enablewebservices)) {
/// for every service than the user is authorised on, create a token (if it doesn't already exist)
///get all services which are set to all user (no restricted to specific users)
$norestrictedservices = $DB->get_records('external_services', array('restrictedusers' => 0));
$serviceidlist = array();
foreach ($norestrictedservices as $service) {
$serviceidlist[] = $service->id;
}
//get all services which are set to the current user (the current user is specified in the restricted user list)
$servicesusers = $DB->get_records('external_services_users', array('userid' => $userid));
foreach ($servicesusers as $serviceuser) {
if (!in_array($serviceuser->externalserviceid,$serviceidlist)) {
$serviceidlist[] = $serviceuser->externalserviceid;
}
}
//get all services which already have a token set for the current user
$usertokens = $DB->get_records('external_tokens', array('userid' => $userid, 'tokentype' => EXTERNAL_TOKEN_PERMANENT));
$tokenizedservice = array();
foreach ($usertokens as $token) {
$tokenizedservice[] = $token->externalserviceid;
}
//create a token for the service which have no token already
foreach ($serviceidlist as $serviceid) {
if (!in_array($serviceid, $tokenizedservice)) {
//create the token for this service
$newtoken = new stdClass();
$newtoken->token = md5(uniqid(rand(),1));
//check that the user has capability on this service
$newtoken->tokentype = EXTERNAL_TOKEN_PERMANENT;
$newtoken->userid = $userid;
$newtoken->externalserviceid = $serviceid;
//TODO: find a way to get the context - UPDATE FOLLOWING LINE
$newtoken->contextid = get_context_instance(CONTEXT_SYSTEM)->id;
$newtoken->creatorid = $userid;
$newtoken->timecreated = time();
$DB->insert_record('external_tokens', $newtoken);
}
}
}
}
/**
* Return all ws user token
* @param integer $userid
* @return array of token
*/
public function get_user_ws_tokens($userid) {
global $DB;
//here retrieve token list (including linked users firstname/lastname and linked services name)
$sql = "SELECT
t.id, t.creatorid, t.token, u.firstname, u.lastname, s.name, t.validuntil
FROM
{external_tokens} t, {user} u, {external_services} s
WHERE
t.userid=? AND t.tokentype = ".EXTERNAL_TOKEN_PERMANENT." AND s.id = t.externalserviceid AND t.userid = u.id";
$tokens = $DB->get_records_sql($sql, array( $userid));
return $tokens;
}
/**
* Return a user token that has been created by the user
* If doesn't exist a exception is thrown
* @param integer $userid
* @param integer $tokenid
* @return object token
* ->id token id
* ->token
* ->firstname user firstname
* ->lastname
* ->name service name
*/
public function get_created_by_user_ws_token($userid, $tokenid) {
global $DB;
$sql = "SELECT
t.id, t.token, u.firstname, u.lastname, s.name
FROM
{external_tokens} t, {user} u, {external_services} s
WHERE
t.creatorid=? AND t.id=? AND t.tokentype = "
. EXTERNAL_TOKEN_PERMANENT
. " AND s.id = t.externalserviceid AND t.userid = u.id";
//must be the token creator
$token = $DB->get_record_sql($sql, array($userid, $tokenid), MUST_EXIST);
return $token;
}
/**
* Return a token for a given id
* @param integer $tokenid
* @return object token
*/
public function get_token_by_id($tokenid) {
global $DB;
return $DB->get_record('external_tokens', array('id' => $tokenid));
}
/**
* Delete a user token
* @param int $tokenid
*/
public function delete_user_ws_token($tokenid) {
global $DB;
$DB->delete_records('external_tokens', array('id'=>$tokenid));
}
/**
* Delete a service - it also delete the functions and users references to this service
* @param int $serviceid
*/
public function delete_service($serviceid) {
global $DB;
$DB->delete_records('external_services_users', array('externalserviceid' => $serviceid));
$DB->delete_records('external_services_functions', array('externalserviceid' => $serviceid));
$DB->delete_records('external_tokens', array('externalserviceid' => $serviceid));
$DB->delete_records('external_services', array('id' => $serviceid));
}
/**
* Get a user token by token
* @param string $token
* @throws moodle_exception if there is multiple result
*/
public function get_user_ws_token($token) {
global $DB;
return $DB->get_record('external_tokens', array('token'=>$token), '*', MUST_EXIST);
}
/**
* Get the list of all functions for given service ids
* @param array $serviceids
* @return array functions
*/
public function get_external_functions($serviceids) {
global $DB;
if (!empty($serviceids)) {
list($serviceids, $params) = $DB->get_in_or_equal($serviceids);
$sql = "SELECT f.*
FROM {external_functions} f
WHERE f.name IN (SELECT sf.functionname
FROM {external_services_functions} sf
WHERE sf.externalserviceid $serviceids)";
$functions = $DB->get_records_sql($sql, $params);
} else {
$functions = array();
}
return $functions;
}
/**
* Get the list of all functions not in the given service id
* @param int $serviceid
* @return array functions
*/
public function get_not_associated_external_functions($serviceid) {
global $DB;
$select = "name NOT IN (SELECT s.functionname
FROM {external_services_functions} s
WHERE s.externalserviceid = :sid
)";
$functions = $DB->get_records_select('external_functions',
$select, array('sid' => $serviceid), 'name');
return $functions;
}
/**
* Get list of required capabilities of a service, sorted by functions
* @param integer $serviceid
* @return array
* example of return value:
* Array
* (
* [moodle_group_create_groups] => Array
* (
* [0] => moodle/course:managegroups
* )
*
* [moodle_enrol_get_enrolled_users] => Array
* (
* [0] => moodle/site:viewparticipants
* [1] => moodle/course:viewparticipants
* [2] => moodle/role:review
* [3] => moodle/site:accessallgroups
* [4] => moodle/course:enrolreview
* )
* )
*/
public function get_service_required_capabilities($serviceid) {
$functions = $this->get_external_functions(array($serviceid));
$requiredusercaps = array();
foreach ($functions as $function) {
$functioncaps = explode(',', $function->capabilities);
if (!empty($functioncaps) and !empty($functioncaps[0])) {
foreach ($functioncaps as $functioncap) {
$requiredusercaps[$function->name][] = trim($functioncap);
}
}
}
return $requiredusercaps;
}
/**
* Get user capabilities (with context)
* Only usefull for documentation purpose
* @param integer $userid
* @return array
*/
public function get_user_capabilities($userid) {
global $DB;
//retrieve the user capabilities
$sql = "SELECT rc.id, rc.capability FROM {role_capabilities} rc, {role_assignments} ra
WHERE rc.roleid=ra.roleid AND ra.userid= ?";
$dbusercaps = $DB->get_records_sql($sql, array($userid));
$usercaps = array();
foreach ($dbusercaps as $usercap) {
$usercaps[$usercap->capability] = true;
}
return $usercaps;
}
/**
* Get users missing capabilities for a given service
* @param array $users
* @param integer $serviceid
* @return array of missing capabilities, the key being the user id
*/
public function get_missing_capabilities_by_users($users, $serviceid) {
global $DB;
$usersmissingcaps = array();
//retrieve capabilities required by the service
$servicecaps = $this->get_service_required_capabilities($serviceid);
//retrieve users missing capabilities
foreach ($users as $user) {
//cast user array into object to be a bit more flexible
if (is_array($user)) {
$user = (object) $user;
}
$usercaps = $this->get_user_capabilities($user->id);
//detect the missing capabilities
foreach ($servicecaps as $functioname => $functioncaps) {
foreach ($functioncaps as $functioncap) {
if (!key_exists($functioncap, $usercaps)) {
if (!isset($usersmissingcaps[$user->id])
or array_search($functioncap, $usersmissingcaps[$user->id]) === false) {
$usersmissingcaps[$user->id][] = $functioncap;
}
}
}
}
}
return $usersmissingcaps;
}
/**
* Get a external service for a given id
* @param service id $serviceid
* @param integer $strictness IGNORE_MISSING, MUST_EXIST...
* @return object external service
*/
public function get_external_service_by_id($serviceid, $strictness=IGNORE_MISSING) {
global $DB;
$service = $DB->get_record('external_services',
array('id' => $serviceid), '*', $strictness);
return $service;
}
/**
* Get a external function for a given id
* @param function id $functionid
* @param integer $strictness IGNORE_MISSING, MUST_EXIST...
* @return object external function
*/
public function get_external_function_by_id($functionid, $strictness=IGNORE_MISSING) {
global $DB;
$function = $DB->get_record('external_functions',
array('id' => $functionid), '*', $strictness);
return $function;
}
/**
* Add a function to a service
* @param string $functionname
* @param integer $serviceid
*/
public function add_external_function_to_service($functionname, $serviceid) {
global $DB;
$addedfunction = new stdClass();
$addedfunction->externalserviceid = $serviceid;
$addedfunction->functionname = $functionname;
$DB->insert_record('external_services_functions', $addedfunction);
}
/**
* Add a service
* @param object $service
* @return serviceid integer
*/
public function add_external_service($service) {
global $DB;
$service->timecreated = mktime();
$serviceid = $DB->insert_record('external_services', $service);
return $serviceid;
}
/**
* Update a service
* @param object $service
*/
public function update_external_service($service) {
global $DB;
$service->timemodified = mktime();
$DB->update_record('external_services', $service);
}
/**
* Test whether a external function is already linked to a service
* @param string $functionname
* @param integer $serviceid
* @return bool true if a matching function exists for the service, else false.
* @throws dml_exception if error
*/
public function service_function_exists($functionname, $serviceid) {
global $DB;
return $DB->record_exists('external_services_functions',
array('externalserviceid' => $serviceid,
'functionname' => $functionname));
}
public function remove_external_function_from_service($functionname, $serviceid) {
global $DB;
$DB->delete_records('external_services_functions',
array('externalserviceid' => $serviceid, 'functionname' => $functionname));
}
}
/**
* Exception indicating access control problem in web service call
* @author Petr Skoda (skodak)
*/
class webservice_access_exception extends moodle_exception {
/**
* Constructor
*/
function __construct($debuginfo) {
parent::__construct('accessexception', 'webservice', '', null, $debuginfo);
}
}
/**
* Is protocol enabled?
* @param string $protocol name of WS protocol
* @return bool
*/
function webservice_protocol_is_enabled($protocol) {
global $CFG;
if (empty($CFG->enablewebservices)) {
return false;
}
$active = explode(',', $CFG->webserviceprotocols);
return(in_array($protocol, $active));
}
//=== WS classes ===
/**
* Mandatory interface for all test client classes.
* @author Petr Skoda (skodak)
*/
interface webservice_test_client_interface {
/**
* Execute test client WS request
* @param string $serverurl
* @param string $function
* @param array $params
* @return mixed
*/
public function simpletest($serverurl, $function, $params);
}
/**
* Mandatory interface for all web service protocol classes
* @author Petr Skoda (skodak)
*/
interface webservice_server_interface {
/**
* Process request from client.
* @return void
*/
public function run();
}
/**
* Abstract web service base class.
* @author Petr Skoda (skodak)
*/
abstract class webservice_server implements webservice_server_interface {
/** @property string $wsname name of the web server plugin */
protected $wsname = null;
/** @property string $username name of local user */
protected $username = null;
/** @property string $password password of the local user */
protected $password = null;
/** @property int $userid the local user */
protected $userid = null;
/** @property integer $authmethod authentication method one of WEBSERVICE_AUTHMETHOD_* */
protected $authmethod;
/** @property string $token authentication token*/
protected $token = null;
/** @property object restricted context */
protected $restricted_context;
/** @property int restrict call to one service id*/
protected $restricted_serviceid = null;
/**
* Contructor
* @param integer $authmethod authentication method one of WEBSERVICE_AUTHMETHOD_*
*/
public function __construct($authmethod) {
$this->authmethod = $authmethod;
}
/**
* Authenticate user using username+password or token.
* This function sets up $USER global.
* It is safe to use has_capability() after this.
* This method also verifies user is allowed to use this
* server.
* @return void
*/
protected function authenticate_user() {
global $CFG, $DB;
if (!NO_MOODLE_COOKIES) {
throw new coding_exception('Cookies must be disabled in WS servers!');
}
if ($this->authmethod == WEBSERVICE_AUTHMETHOD_USERNAME) {
//we check that authentication plugin is enabled
//it is only required by simple authentication
if (!is_enabled_auth('webservice')) {
throw new webservice_access_exception(get_string('wsauthnotenabled', 'webservice'));
}
if (!$auth = get_auth_plugin('webservice')) {
throw new webservice_access_exception(get_string('wsauthmissing', 'webservice'));
}
$this->restricted_context = get_context_instance(CONTEXT_SYSTEM);
if (!$this->username) {
throw new webservice_access_exception(get_string('missingusername', 'webservice'));
}
if (!$this->password) {
throw new webservice_access_exception(get_string('missingpassword', 'webservice'));
}
if (!$auth->user_login_webservice($this->username, $this->password)) {
// log failed login attempts
add_to_log(SITEID, 'webservice', get_string('simpleauthlog', 'webservice'), '' , get_string('failedtolog', 'webservice').": ".$this->username."/".$this->password." - ".getremoteaddr() , 0);
throw new webservice_access_exception(get_string('wrongusernamepassword', 'webservice'));
}
$user = $DB->get_record('user', array('username'=>$this->username, 'mnethostid'=>$CFG->mnet_localhost_id, 'deleted'=>0), '*', MUST_EXIST);
} else if ($this->authmethod == WEBSERVICE_AUTHMETHOD_PERMANENT_TOKEN){
$user = $this->authenticate_by_token(EXTERNAL_TOKEN_PERMANENT);
} else {
$user = $this->authenticate_by_token(EXTERNAL_TOKEN_EMBEDDED);
}
// now fake user login, the session is completely empty too
session_set_user($user);
$this->userid = $user->id;
if ($this->authmethod != WEBSERVICE_AUTHMETHOD_SESSION_TOKEN && !has_capability("webservice/$this->wsname:use", $this->restricted_context)) {
throw new webservice_access_exception(get_string('accessnotallowed', 'webservice'));
}
external_api::set_context_restriction($this->restricted_context);
}
protected function authenticate_by_token($tokentype){
global $DB;
if (!$token = $DB->get_record('external_tokens', array('token'=>$this->token, 'tokentype'=>$tokentype))) {
// log failed login attempts
add_to_log(SITEID, 'webservice', get_string('tokenauthlog', 'webservice'), '' , get_string('failedtolog', 'webservice').": ".$this->token. " - ".getremoteaddr() , 0);
throw new webservice_access_exception(get_string('invalidtoken', 'webservice'));
}
if ($token->validuntil and $token->validuntil < time()) {
$DB->delete_records('external_tokens', array('token'=>$this->token, 'tokentype'=>$tokentype));
throw new webservice_access_exception(get_string('invalidtimedtoken', 'webservice'));
}
if ($token->sid){//assumes that if sid is set then there must be a valid associated session no matter the token type
$session = session_get_instance();
if (!$session->session_exists($token->sid)){
$DB->delete_records('external_tokens', array('sid'=>$token->sid));
throw new webservice_access_exception(get_string('invalidtokensession', 'webservice'));
}
}
if ($token->iprestriction and !address_in_subnet(getremoteaddr(), $token->iprestriction)) {
add_to_log(SITEID, 'webservice', get_string('tokenauthlog', 'webservice'), '' , get_string('failedtolog', 'webservice').": ".getremoteaddr() , 0);
throw new webservice_access_exception(get_string('invalidiptoken', 'webservice'));
}
$this->restricted_context = get_context_instance_by_id($token->contextid);
$this->restricted_serviceid = $token->externalserviceid;
$user = $DB->get_record('user', array('id'=>$token->userid, 'deleted'=>0), '*', MUST_EXIST);
// log token access
$DB->set_field('external_tokens', 'lastaccess', time(), array('id'=>$token->id));
return $user;
}
}
/**
* Special abstraction of our srvices that allows
* interaction with stock Zend ws servers.
* @author Petr Skoda (skodak)
*/
abstract class webservice_zend_server extends webservice_server {
/** @property string name of the zend server class : Zend_XmlRpc_Server, Zend_Soap_Server, Zend_Soap_AutoDiscover, ...*/
protected $zend_class;
/** @property object Zend server instance */
protected $zend_server;
/** @property string $service_class virtual web service class with all functions user name execute, created on the fly */
protected $service_class;
/**
* Contructor
* @param integer $authmethod authentication method - one of WEBSERVICE_AUTHMETHOD_*
*/
public function __construct($authmethod, $zend_class) {
parent::__construct($authmethod);
$this->zend_class = $zend_class;
}
/**
* Process request from client.
* @param bool $simple use simple authentication
* @return void
*/
public function run() {
// we will probably need a lot of memory in some functions
raise_memory_limit(MEMORY_EXTRA);
// set some longer timeout, this script is not sending any output,
// this means we need to manually extend the timeout operations
// that need longer time to finish
external_api::set_timeout();
// now create the instance of zend server
$this->init_zend_server();
// set up exception handler first, we want to sent them back in correct format that
// the other system understands
// we do not need to call the original default handler because this ws handler does everything
set_exception_handler(array($this, 'exception_handler'));
// init all properties from the request data
$this->parse_request();
// this sets up $USER and $SESSION and context restrictions
$this->authenticate_user();
// make a list of all functions user is allowed to excecute
$this->init_service_class();
// tell server what functions are available
$this->zend_server->setClass($this->service_class);
//log the web service request
add_to_log(SITEID, 'webservice', '', '' , $this->zend_class." ".getremoteaddr() , 0, $this->userid);
// execute and return response, this sends some headers too
$response = $this->zend_server->handle();
// session cleanup
$this->session_cleanup();
//finally send the result
$this->send_headers();
echo $response;
die;
}
/**
* Load virtual class needed for Zend api
* @return void
*/
protected function init_service_class() {
global $USER, $DB;
// first ofall get a complete list of services user is allowed to access
if ($this->restricted_serviceid) {
$params = array('sid1'=>$this->restricted_serviceid, 'sid2'=>$this->restricted_serviceid);
$wscond1 = 'AND s.id = :sid1';
$wscond2 = 'AND s.id = :sid2';
} else {
$params = array();
$wscond1 = '';
$wscond2 = '';
}
// now make sure the function is listed in at least one service user is allowed to use
// allow access only if:
// 1/ entry in the external_services_users table if required
// 2/ validuntil not reached
// 3/ has capability if specified in service desc
// 4/ iprestriction
$sql = "SELECT s.*, NULL AS iprestriction
FROM {external_services} s
JOIN {external_services_functions} sf ON (sf.externalserviceid = s.id AND s.restrictedusers = 0)
WHERE s.enabled = 1 $wscond1
UNION
SELECT s.*, su.iprestriction
FROM {external_services} s
JOIN {external_services_functions} sf ON (sf.externalserviceid = s.id AND s.restrictedusers = 1)
JOIN {external_services_users} su ON (su.externalserviceid = s.id AND su.userid = :userid)
WHERE s.enabled = 1 AND su.validuntil IS NULL OR su.validuntil < :now $wscond2";
$params = array_merge($params, array('userid'=>$USER->id, 'now'=>time()));
$serviceids = array();
$rs = $DB->get_recordset_sql($sql, $params);
// now make sure user may access at least one service
$remoteaddr = getremoteaddr();
$allowed = false;
foreach ($rs as $service) {
if (isset($serviceids[$service->id])) {
continue;
}
if ($service->requiredcapability and !has_capability($service->requiredcapability, $this->restricted_context)) {
continue; // cap required, sorry
}
if ($service->iprestriction and !address_in_subnet($remoteaddr, $service->iprestriction)) {
continue; // wrong request source ip, sorry
}
$serviceids[$service->id] = $service->id;
}
$rs->close();
// now get the list of all functions
$wsmanager = new webservice();
$functions = $wsmanager->get_external_functions($serviceids);
// now make the virtual WS class with all the fuctions for this particular user
$methods = '';
foreach ($functions as $function) {
$methods .= $this->get_virtual_method_code($function);
}
// let's use unique class name, there might be problem in unit tests
$classname = 'webservices_virtual_class_000000';
while(class_exists($classname)) {
$classname++;
}
$code = '
/**
* Virtual class web services for user id '.$USER->id.' in context '.$this->restricted_context->id.'.
*/
class '.$classname.' {
'.$methods.'
}
';
// load the virtual class definition into memory
eval($code);
$this->service_class = $classname;
}
/**
* returns virtual method code
* @param object $function
* @return string PHP code
*/
protected function get_virtual_method_code($function) {
global $CFG;
$function = external_function_info($function);
//arguments in function declaration line with defaults.
$paramanddefaults = array();
//arguments used as parameters for external lib call.
$params = array();
$params_desc = array();
foreach ($function->parameters_desc->keys as $name=>$keydesc) {
$param = '$'.$name;
$paramanddefault = $param;
//need to generate the default if there is any
if ($keydesc instanceof external_value) {
if ($keydesc->required == VALUE_DEFAULT) {
if ($keydesc->default===null) {
$paramanddefault .= '=null';
} else {
switch($keydesc->type) {
case PARAM_BOOL:
$paramanddefault .= '='.$keydesc->default; break;
case PARAM_INT:
$paramanddefault .= '='.$keydesc->default; break;
case PARAM_FLOAT;
$paramanddefault .= '='.$keydesc->default; break;
default:
$paramanddefault .= '=\''.$keydesc->default.'\'';
}
}
} else if ($keydesc->required == VALUE_OPTIONAL) {
//it does make sens to declare a parameter VALUE_OPTIONAL
//VALUE_OPTIONAL is used only for array/object key
throw new moodle_exception('parametercannotbevalueoptional');
}
} else { //for the moment we do not support default for other structure types
if ($keydesc->required == VALUE_DEFAULT) {
//accept empty array as default
if (isset($keydesc->default) and is_array($keydesc->default)
and empty($keydesc->default)) {
$paramanddefault .= '=array()';
} else {
throw new moodle_exception('errornotemptydefaultparamarray', 'webservice', '', $name);
}
}
if ($keydesc->required == VALUE_OPTIONAL) {
throw new moodle_exception('erroroptionalparamarray', 'webservice', '', $name);
}
}
$params[] = $param;
$paramanddefaults[] = $paramanddefault;
$type = 'string';
if ($keydesc instanceof external_value) {
switch($keydesc->type) {
case PARAM_BOOL: // 0 or 1 only for now
case PARAM_INT:
$type = 'int'; break;
case PARAM_FLOAT;
$type = 'double'; break;
default:
$type = 'string';
}
} else if ($keydesc instanceof external_single_structure) {
$type = 'object|struct';
} else if ($keydesc instanceof external_multiple_structure) {
$type = 'array';
}
$params_desc[] = ' * @param '.$type.' $'.$name.' '.$keydesc->desc;
}
$params = implode(', ', $params);
$paramanddefaults = implode(', ', $paramanddefaults);
$params_desc = implode("\n", $params_desc);
$serviceclassmethodbody = $this->service_class_method_body($function, $params);
if (is_null($function->returns_desc)) {
$return = ' * @return void';
} else {
$type = 'string';
if ($function->returns_desc instanceof external_value) {
switch($function->returns_desc->type) {
case PARAM_BOOL: // 0 or 1 only for now
case PARAM_INT:
$type = 'int'; break;
case PARAM_FLOAT;
$type = 'double'; break;
default:
$type = 'string';
}
} else if ($function->returns_desc instanceof external_single_structure) {
$type = 'object|struct'; //only 'object' is supported by SOAP, 'struct' by XML-RPC MDL-23083
} else if ($function->returns_desc instanceof external_multiple_structure) {
$type = 'array';
}
$return = ' * @return '.$type.' '.$function->returns_desc->desc;
}
// now crate the virtual method that calls the ext implementation
$code = '
/**
* '.$function->description.'
*
'.$params_desc.'
'.$return.'
*/
public function '.$function->name.'('.$paramanddefaults.') {
'.$serviceclassmethodbody.'
}
';
return $code;
}
/**
* You can override this function in your child class to add extra code into the dynamically
* created service class. For example it is used in the amf server to cast types of parameters and to
* cast the return value to the types as specified in the return value description.
* @param stdClass $function
* @param array $params
* @return string body of the method for $function ie. everything within the {} of the method declaration.
*/
protected function service_class_method_body($function, $params){
//cast the param from object to array (validate_parameters except array only)
$castingcode = '';
if ($params){
$paramstocast = explode(',', $params);
foreach ($paramstocast as $paramtocast) {
//clean the parameter from any white space
$paramtocast = trim($paramtocast);
$castingcode .= $paramtocast .
'=webservice_zend_server::cast_objects_to_array('.$paramtocast.');';
}
}
$descriptionmethod = $function->methodname.'_returns()';
$callforreturnvaluedesc = $function->classname.'::'.$descriptionmethod;
return $castingcode . ' if ('.$callforreturnvaluedesc.' == null) {'.
$function->classname.'::'.$function->methodname.'('.$params.');
return null;
}
return external_api::clean_returnvalue('.$callforreturnvaluedesc.', '.$function->classname.'::'.$function->methodname.'('.$params.'));';
}
/**
* Recursive function to recurse down into a complex variable and convert all
* objects to arrays.
* @param mixed $param value to cast
* @return mixed Cast value
*/
public static function cast_objects_to_array($param){
if (is_object($param)){
$param = (array)$param;
}
if (is_array($param)){
$toreturn = array();
foreach ($param as $key=> $param){
$toreturn[$key] = self::cast_objects_to_array($param);
}
return $toreturn;
} else {
return $param;
}
}
/**
* Set up zend service class
* @return void
*/
protected function init_zend_server() {
$this->zend_server = new $this->zend_class();
}
/**
* This method parses the $_REQUEST superglobal and looks for
* the following information:
* 1/ user authentication - username+password or token (wsusername, wspassword and wstoken parameters)
*
* @return void
*/
protected function parse_request() {
if ($this->authmethod == WEBSERVICE_AUTHMETHOD_USERNAME) {
//note: some clients have problems with entity encoding :-(
if (isset($_REQUEST['wsusername'])) {
$this->username = $_REQUEST['wsusername'];
}
if (isset($_REQUEST['wspassword'])) {
$this->password = $_REQUEST['wspassword'];
}
} else {
if (isset($_REQUEST['wstoken'])) {
$this->token = $_REQUEST['wstoken'];
}
}
}
/**
* Internal implementation - sending of page headers.
* @return void
*/
protected function send_headers() {
header('Cache-Control: private, must-revalidate, pre-check=0, post-check=0, max-age=0');
header('Expires: '. gmdate('D, d M Y H:i:s', 0) .' GMT');
header('Pragma: no-cache');
header('Accept-Ranges: none');
}
/**
* Specialised exception handler, we can not use the standard one because
* it can not just print html to output.
*
* @param exception $ex
* @return void does not return
*/
public function exception_handler($ex) {
// detect active db transactions, rollback and log as error
abort_all_db_transactions();
// some hacks might need a cleanup hook
$this->session_cleanup($ex);
// now let the plugin send the exception to client
$this->send_error($ex);
// not much else we can do now, add some logging later
exit(1);
}
/**
* Send the error information to the WS client
* formatted as XML document.
* @param exception $ex
* @return void
*/
protected function send_error($ex=null) {
$this->send_headers();
echo $this->zend_server->fault($ex);
}
/**
* Future hook needed for emulated sessions.
* @param exception $exception null means normal termination, $exception received when WS call failed
* @return void
*/
protected function session_cleanup($exception=null) {
if ($this->authmethod == WEBSERVICE_AUTHMETHOD_USERNAME) {
// nothing needs to be done, there is no persistent session
} else {
// close emulated session if used
}
}
}
/**
* Web Service server base class, this class handles both
* simple and token authentication.
* @author Petr Skoda (skodak)
*/
abstract class webservice_base_server extends webservice_server {
/** @property array $parameters the function parameters - the real values submitted in the request */
protected $parameters = null;
/** @property string $functionname the name of the function that is executed */
protected $functionname = null;
/** @property object $function full function description */
protected $function = null;
/** @property mixed $returns function return value */
protected $returns = null;
/**
* This method parses the request input, it needs to get:
* 1/ user authentication - username+password or token
* 2/ function name
* 3/ function parameters
*
* @return void
*/
abstract protected function parse_request();
/**
* Send the result of function call to the WS client.
* @return void
*/
abstract protected function send_response();
/**
* Send the error information to the WS client.
* @param exception $ex
* @return void
*/
abstract protected function send_error($ex=null);
/**
* Process request from client.
* @return void
*/
public function run() {
// we will probably need a lot of memory in some functions
raise_memory_limit(MEMORY_EXTRA);
// set some longer timeout, this script is not sending any output,
// this means we need to manually extend the timeout operations
// that need longer time to finish
external_api::set_timeout();
// set up exception handler first, we want to sent them back in correct format that
// the other system understands
// we do not need to call the original default handler because this ws handler does everything
set_exception_handler(array($this, 'exception_handler'));
// init all properties from the request data
$this->parse_request();
// authenticate user, this has to be done after the request parsing
// this also sets up $USER and $SESSION
$this->authenticate_user();
// find all needed function info and make sure user may actually execute the function
$this->load_function_info();
//log the web service request
add_to_log(SITEID, 'webservice', $this->functionname, '' , getremoteaddr() , 0, $this->userid);
// finally, execute the function - any errors are catched by the default exception handler
$this->execute();
// send the results back in correct format
$this->send_response();
// session cleanup
$this->session_cleanup();
die;
}
/**
* Specialised exception handler, we can not use the standard one because
* it can not just print html to output.
*
* @param exception $ex
* @return void does not return
*/
public function exception_handler($ex) {
// detect active db transactions, rollback and log as error
abort_all_db_transactions();
// some hacks might need a cleanup hook
$this->session_cleanup($ex);
// now let the plugin send the exception to client
$this->send_error($ex);
// not much else we can do now, add some logging later
exit(1);
}
/**
* Future hook needed for emulated sessions.
* @param exception $exception null means normal termination, $exception received when WS call failed
* @return void
*/
protected function session_cleanup($exception=null) {
if ($this->authmethod == WEBSERVICE_AUTHMETHOD_USERNAME) {
// nothing needs to be done, there is no persistent session
} else {
// close emulated session if used
}
}
/**
* Fetches the function description from database,
* verifies user is allowed to use this function and
* loads all paremeters and return descriptions.
* @return void
*/
protected function load_function_info() {
global $DB, $USER, $CFG;
if (empty($this->functionname)) {
throw new invalid_parameter_exception('Missing function name');
}
// function must exist
$function = external_function_info($this->functionname);
if ($this->restricted_serviceid) {
$params = array('sid1'=>$this->restricted_serviceid, 'sid2'=>$this->restricted_serviceid);
$wscond1 = 'AND s.id = :sid1';
$wscond2 = 'AND s.id = :sid2';
} else {
$params = array();
$wscond1 = '';
$wscond2 = '';
}
// now let's verify access control
// now make sure the function is listed in at least one service user is allowed to use
// allow access only if:
// 1/ entry in the external_services_users table if required
// 2/ validuntil not reached
// 3/ has capability if specified in service desc
// 4/ iprestriction
$sql = "SELECT s.*, NULL AS iprestriction
FROM {external_services} s
JOIN {external_services_functions} sf ON (sf.externalserviceid = s.id AND s.restrictedusers = 0 AND sf.functionname = :name1)
WHERE s.enabled = 1 $wscond1
UNION
SELECT s.*, su.iprestriction
FROM {external_services} s
JOIN {external_services_functions} sf ON (sf.externalserviceid = s.id AND s.restrictedusers = 1 AND sf.functionname = :name2)
JOIN {external_services_users} su ON (su.externalserviceid = s.id AND su.userid = :userid)
WHERE s.enabled = 1 AND su.validuntil IS NULL OR su.validuntil < :now $wscond2";
$params = array_merge($params, array('userid'=>$USER->id, 'name1'=>$function->name, 'name2'=>$function->name, 'now'=>time()));
$rs = $DB->get_recordset_sql($sql, $params);
// now make sure user may access at least one service
$remoteaddr = getremoteaddr();
$allowed = false;
foreach ($rs as $service) {
if ($service->requiredcapability and !has_capability($service->requiredcapability, $this->restricted_context)) {
continue; // cap required, sorry
}
if ($service->iprestriction and !address_in_subnet($remoteaddr, $service->iprestriction)) {
continue; // wrong request source ip, sorry
}
$allowed = true;
break; // one service is enough, no need to continue
}
$rs->close();
if (!$allowed) {
throw new webservice_access_exception('Access to external function not allowed');
}
// we have all we need now
$this->function = $function;
}
/**
* Execute previously loaded function using parameters parsed from the request data.
* @return void
*/
protected function execute() {
// validate params, this also sorts the params properly, we need the correct order in the next part
$params = call_user_func(array($this->function->classname, 'validate_parameters'), $this->function->parameters_desc, $this->parameters);
// execute - yay!
$this->returns = call_user_func_array(array($this->function->classname, $this->function->methodname), array_values($params));
}
}
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