<?php
namespace Sabre\DAV\Locks;
use Sabre\DAV;
use Sabre\HTTP\RequestInterface;
use Sabre\HTTP\ResponseInterface;
/**
* Locking plugin
*
* This plugin provides locking support to a WebDAV server.
* The easiest way to get started, is by hooking it up as such:
*
* $lockBackend = new Sabre\DAV\Locks\Backend\File('./mylockdb');
* $lockPlugin = new Sabre\DAV\Locks\Plugin($lockBackend);
* $server->addPlugin($lockPlugin);
*
* @copyright Copyright (C) fruux GmbH (https://fruux.com/)
* @author Evert Pot (http://evertpot.com/)
* @license http://sabre.io/license/ Modified BSD License
*/
class Plugin extends DAV\ServerPlugin {
/**
* locksBackend
*
* @var Backend\Backend\Interface
*/
protected $locksBackend;
/**
* server
*
* @var Sabre\DAV\Server
*/
protected $server;
/**
* __construct
*
* @param Backend\BackendInterface $locksBackend
*/
function __construct(Backend\BackendInterface $locksBackend) {
$this->locksBackend = $locksBackend;
}
/**
* Initializes the plugin
*
* This method is automatically called by the Server class after addPlugin.
*
* @param DAV\Server $server
* @return void
*/
function initialize(DAV\Server $server) {
$this->server = $server;
$this->server->xml->elementMap['{DAV:}lockinfo'] = 'Sabre\\DAV\\Xml\\Request\\Lock';
$server->on('method:LOCK', [$this, 'httpLock']);
$server->on('method:UNLOCK', [$this, 'httpUnlock']);
$server->on('validateTokens', [$this, 'validateTokens']);
$server->on('propFind', [$this, 'propFind']);
$server->on('afterUnbind', [$this, 'afterUnbind']);
}
/**
* Returns a plugin name.
*
* Using this name other plugins will be able to access other plugins
* using Sabre\DAV\Server::getPlugin
*
* @return string
*/
function getPluginName() {
return 'locks';
}
/**
* This method is called after most properties have been found
* it allows us to add in any Lock-related properties
*
* @param DAV\PropFind $propFind
* @param DAV\INode $node
* @return void
*/
function propFind(DAV\PropFind $propFind, DAV\INode $node) {
$propFind->handle('{DAV:}supportedlock', function() {
return new DAV\Xml\Property\SupportedLock();
});
$propFind->handle('{DAV:}lockdiscovery', function() use ($propFind) {
return new DAV\Xml\Property\LockDiscovery(
$this->getLocks($propFind->getPath())
);
});
}
/**
* Use this method to tell the server this plugin defines additional
* HTTP methods.
*
* This method is passed a uri. It should only return HTTP methods that are
* available for the specified uri.
*
* @param string $uri
* @return array
*/
function getHTTPMethods($uri) {
return ['LOCK','UNLOCK'];
}
/**
* Returns a list of features for the HTTP OPTIONS Dav: header.
*
* In this case this is only the number 2. The 2 in the Dav: header
* indicates the server supports locks.
*
* @return array
*/
function getFeatures() {
return [2];
}
/**
* Returns all lock information on a particular uri
*
* This function should return an array with Sabre\DAV\Locks\LockInfo objects. If there are no locks on a file, return an empty array.
*
* Additionally there is also the possibility of locks on parent nodes, so we'll need to traverse every part of the tree
* If the $returnChildLocks argument is set to true, we'll also traverse all the children of the object
* for any possible locks and return those as well.
*
* @param string $uri
* @param bool $returnChildLocks
* @return array
*/
function getLocks($uri, $returnChildLocks = false) {
return $this->locksBackend->getLocks($uri, $returnChildLocks);
}
/**
* Locks an uri
*
* The WebDAV lock request can be operated to either create a new lock on a file, or to refresh an existing lock
* If a new lock is created, a full XML body should be supplied, containing information about the lock such as the type
* of lock (shared or exclusive) and the owner of the lock
*
* If a lock is to be refreshed, no body should be supplied and there should be a valid If header containing the lock
*
* Additionally, a lock can be requested for a non-existent file. In these case we're obligated to create an empty file as per RFC4918:S7.3
*
* @param RequestInterface $request
* @param ResponseInterface $response
* @return bool
*/
function httpLock(RequestInterface $request, ResponseInterface $response) {
$uri = $request->getPath();
$existingLocks = $this->getLocks($uri);
if ($body = $request->getBodyAsString()) {
// This is a new lock request
$existingLock = null;
// Checking if there's already non-shared locks on the uri.
foreach ($existingLocks as $existingLock) {
if ($existingLock->scope === LockInfo::EXCLUSIVE) {
throw new DAV\Exception\ConflictingLock($existingLock);
}
}
$lockInfo = $this->parseLockRequest($body);
$lockInfo->depth = $this->server->getHTTPDepth();
$lockInfo->uri = $uri;
if ($existingLock && $lockInfo->scope != LockInfo::SHARED)
throw new DAV\Exception\ConflictingLock($existingLock);
} else {
// Gonna check if this was a lock refresh.
$existingLocks = $this->getLocks($uri);
$conditions = $this->server->getIfConditions($request);
$found = null;
foreach ($existingLocks as $existingLock) {
foreach ($conditions as $condition) {
foreach ($condition['tokens'] as $token) {
if ($token['token'] === 'opaquelocktoken:' . $existingLock->token) {
$found = $existingLock;
break 3;
}
}
}
}
// If none were found, this request is in error.
if (is_null($found)) {
if ($existingLocks) {
throw new DAV\Exception\Locked(reset($existingLocks));
} else {
throw new DAV\Exception\BadRequest('An xml body is required for lock requests');
}
}
// This must have been a lock refresh
$lockInfo = $found;
// The resource could have been locked through another uri.
if ($uri != $lockInfo->uri) $uri = $lockInfo->uri;
}
if ($timeout = $this->getTimeoutHeader()) $lockInfo->timeout = $timeout;
$newFile = false;
// If we got this far.. we should go check if this node actually exists. If this is not the case, we need to create it first
try {
$this->server->tree->getNodeForPath($uri);
// We need to call the beforeWriteContent event for RFC3744
// Edit: looks like this is not used, and causing problems now.
//
// See Issue 222
// $this->server->emit('beforeWriteContent',array($uri));
} catch (DAV\Exception\NotFound $e) {
// It didn't, lets create it
$this->server->createFile($uri, fopen('php://memory', 'r'));
$newFile = true;
}
$this->lockNode($uri, $lockInfo);
$response->setHeader('Content-Type', 'application/xml; charset=utf-8');
$response->setHeader('Lock-Token', '<opaquelocktoken:' . $lockInfo->token . '>');
$response->setStatus($newFile ? 201 : 200);
$response->setBody($this->generateLockResponse($lockInfo));
// Returning false will interupt the event chain and mark this method
// as 'handled'.
return false;
}
/**
* Unlocks a uri
*
* This WebDAV method allows you to remove a lock from a node. The client should provide a valid locktoken through the Lock-token http header
* The server should return 204 (No content) on success
*
* @param RequestInterface $request
* @param ResponseInterface $response
* @return void
*/
function httpUnlock(RequestInterface $request, ResponseInterface $response) {
$lockToken = $request->getHeader('Lock-Token');
// If the locktoken header is not supplied, we need to throw a bad request exception
if (!$lockToken) throw new DAV\Exception\BadRequest('No lock token was supplied');
$path = $request->getPath();
$locks = $this->getLocks($path);
// Windows sometimes forgets to include < and > in the Lock-Token
// header
if ($lockToken[0] !== '<') $lockToken = '<' . $lockToken . '>';
foreach ($locks as $lock) {
if ('<opaquelocktoken:' . $lock->token . '>' == $lockToken) {
$this->unlockNode($path, $lock);
$response->setHeader('Content-Length', '0');
$response->setStatus(204);
// Returning false will break the method chain, and mark the
// method as 'handled'.
return false;
}
}
// If we got here, it means the locktoken was invalid
throw new DAV\Exception\LockTokenMatchesRequestUri();
}
/**
* This method is called after a node is deleted.
*
* We use this event to clean up any locks that still exist on the node.
*
* @param string $path
* @return void
*/
function afterUnbind($path) {
$locks = $this->getLocks($path, $includeChildren = true);
foreach ($locks as $lock) {
$this->unlockNode($path, $lock);
}
}
/**
* Locks a uri
*
* All the locking information is supplied in the lockInfo object. The object has a suggested timeout, but this can be safely ignored
* It is important that if the existing timeout is ignored, the property is overwritten, as this needs to be sent back to the client
*
* @param string $uri
* @param LockInfo $lockInfo
* @return bool
*/
function lockNode($uri, LockInfo $lockInfo) {
if (!$this->server->emit('beforeLock', [$uri, $lockInfo])) return;
return $this->locksBackend->lock($uri, $lockInfo);
}
/**
* Unlocks a uri
*
* This method removes a lock from a uri. It is assumed all the supplied information is correct and verified
*
* @param string $uri
* @param LockInfo $lockInfo
* @return bool
*/
function unlockNode($uri, LockInfo $lockInfo) {
if (!$this->server->emit('beforeUnlock', [$uri, $lockInfo])) return;
return $this->locksBackend->unlock($uri, $lockInfo);
}
/**
* Returns the contents of the HTTP Timeout header.
*
* The method formats the header into an integer.
*
* @return int
*/
function getTimeoutHeader() {
$header = $this->server->httpRequest->getHeader('Timeout');
if ($header) {
if (stripos($header, 'second-') === 0) $header = (int)(substr($header, 7));
elseif (stripos($header, 'infinite') === 0) $header = LockInfo::TIMEOUT_INFINITE;
else throw new DAV\Exception\BadRequest('Invalid HTTP timeout header');
} else {
$header = 0;
}
return $header;
}
/**
* Generates the response for successful LOCK requests
*
* @param LockInfo $lockInfo
* @return string
*/
protected function generateLockResponse(LockInfo $lockInfo) {
return $this->server->xml->write('{DAV:}prop', [
'{DAV:}lockdiscovery' =>
new DAV\Xml\Property\LockDiscovery([$lockInfo])
]);
}
/**
* The validateTokens event is triggered before every request.
*
* It's a moment where this plugin can check all the supplied lock tokens
* in the If: header, and check if they are valid.
*
* In addition, it will also ensure that it checks any missing lokens that
* must be present in the request, and reject requests without the proper
* tokens.
*
* @param RequestInterface $request
* @param mixed $conditions
* @return void
*/
function validateTokens(RequestInterface $request, &$conditions) {
// First we need to gather a list of locks that must be satisfied.
$mustLocks = [];
$method = $request->getMethod();
// Methods not in that list are operations that doesn't alter any
// resources, and we don't need to check the lock-states for.
switch ($method) {
case 'DELETE' :
$mustLocks = array_merge($mustLocks, $this->getLocks(
$request->getPath(),
true
));
break;
case 'MKCOL' :
case 'MKCALENDAR' :
case 'PROPPATCH' :
case 'PUT' :
case 'PATCH' :
$mustLocks = array_merge($mustLocks, $this->getLocks(
$request->getPath(),
false
));
break;
case 'MOVE' :
$mustLocks = array_merge($mustLocks, $this->getLocks(
$request->getPath(),
true
));
$mustLocks = array_merge($mustLocks, $this->getLocks(
$this->server->calculateUri($request->getHeader('Destination')),
false
));
break;
case 'COPY' :
$mustLocks = array_merge($mustLocks, $this->getLocks(
$this->server->calculateUri($request->getHeader('Destination')),
false
));
break;
case 'LOCK' :
//Temporary measure.. figure out later why this is needed
// Here we basically ignore all incoming tokens...
foreach ($conditions as $ii => $condition) {
foreach ($condition['tokens'] as $jj => $token) {
$conditions[$ii]['tokens'][$jj]['validToken'] = true;
}
}
return;
}
// It's possible that there's identical locks, because of shared
// parents. We're removing the duplicates here.
$tmp = [];
foreach ($mustLocks as $lock) $tmp[$lock->token] = $lock;
$mustLocks = array_values($tmp);
foreach ($conditions as $kk => $condition) {
foreach ($condition['tokens'] as $ii => $token) {
// Lock tokens always start with opaquelocktoken:
if (substr($token['token'], 0, 16) !== 'opaquelocktoken:') {
continue;
}
$checkToken = substr($token['token'], 16);
// Looping through our list with locks.
foreach ($mustLocks as $jj => $mustLock) {
if ($mustLock->token == $checkToken) {
// We have a match!
// Removing this one from mustlocks
unset($mustLocks[$jj]);
// Marking the condition as valid.
$conditions[$kk]['tokens'][$ii]['validToken'] = true;
// Advancing to the next token
continue 2;
}
}
// If we got here, it means that there was a
// lock-token, but it was not in 'mustLocks'.
//
// This is an edge-case, as it could mean that token
// was specified with a url that was not 'required' to
// check. So we're doing one extra lookup to make sure
// we really don't know this token.
//
// This also gets triggered when the user specified a
// lock-token that was expired.
$oddLocks = $this->getLocks($condition['uri']);
foreach ($oddLocks as $oddLock) {
if ($oddLock->token === $checkToken) {
// We have a hit!
$conditions[$kk]['tokens'][$ii]['validToken'] = true;
continue 2;
}
}
// If we get all the way here, the lock-token was
// really unknown.
}
}
// If there's any locks left in the 'mustLocks' array, it means that
// the resource was locked and we must block it.
if ($mustLocks) {
throw new DAV\Exception\Locked(reset($mustLocks));
}
}
/**
* Parses a webdav lock xml body, and returns a new Sabre\DAV\Locks\LockInfo object
*
* @param string $body
* @return LockInfo
*/
protected function parseLockRequest($body) {
$result = $this->server->xml->expect(
'{DAV:}lockinfo',
$body
);
$lockInfo = new LockInfo();
$lockInfo->owner = $result->owner;
$lockInfo->token = DAV\UUIDUtil::getUUID();
$lockInfo->scope = $result->scope;
return $lockInfo;
}
/**
* Returns a bunch of meta-data about the plugin.
*
* Providing this information is optional, and is mainly displayed by the
* Browser plugin.
*
* The description key in the returned array may contain html and will not
* be sanitized.
*
* @return array
*/
function getPluginInfo() {
return [
'name' => $this->getPluginName(),
'description' => 'The locks plugin turns this server into a class-2 WebDAV server and adds support for LOCK and UNLOCK',
'link' => 'http://sabre.io/dav/locks/',
];
}
}
