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[Oembed] Refactoring and some improvements (namely documentation)

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Imported some changes from postActiv
This commit is contained in:
Diogo Cordeiro
2018-07-18 05:31:24 +01:00
parent d705bcbd98
commit 01b5118c6f
9 changed files with 536 additions and 237 deletions
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330
plugins/Oembed/OembedPlugin.php
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@@ -1,7 +1,40 @@
<?php
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// GNU social 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with GNU social. If not, see <http://www.gnu.org/licenses/>.
if (!defined('GNUSOCIAL')) { exit(1); }
/**
* OembedPlugin implementation for GNU social
*
* @package GNUsocial
* @author Stephen Paul Weber
* @author hannes
* @author Mikael Nordfeldth
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @copyright 2019 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
defined('GNUSOCIAL') || die();
/**
* Base class for the oEmbed plugin that does most of the heavy lifting to get
* and display representations for remote content.
*
* @copyright 2019 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
class OembedPlugin extends Plugin
{
const PLUGIN_VERSION = '2.0.0';
@@ -12,12 +45,16 @@ class OembedPlugin extends Plugin
'^i\d*\.ytimg\.com$' => 'YouTube',
'^i\d*\.vimeocdn\.com$' => 'Vimeo',
);
public $append_whitelist = array(); // fill this array as domain_whitelist to add more trusted sources
public $append_whitelist = array(); // fill this array as domain_whitelist to add more trusted sources
public $check_whitelist = false; // security/abuse precaution
protected $imgData = array();
// these should be declared protected everywhere
/**
* Initialize the oEmbed plugin and set up the environment it needs for it.
* Returns true if it initialized properly, the exception object if it
* doesn't.
*/
public function initialize()
{
parent::initialize();
@@ -25,6 +62,12 @@ class OembedPlugin extends Plugin
$this->domain_whitelist = array_merge($this->domain_whitelist, $this->append_whitelist);
}
/**
* The code executed on GNU social checking the database schema, which in
* this case is to make sure we have the plugin table we need.
*
* @return bool true if it ran successfully, the exception object if it doesn't.
*/
public function onCheckSchema()
{
$schema = Schema::get();
@@ -32,11 +75,28 @@ class OembedPlugin extends Plugin
return true;
}
/**
* This code executes when GNU social creates the page routing, and we hook
* on this event to add our action handler for oEmbed.
*
* @param $m URLMapper the router that was initialized.
* @return bool true if successful, the exception object if it isn't.
*/
public function onRouterInitialized(URLMapper $m)
{
$m->connect('main/oembed', array('action' => 'oembed'));
}
/**
* This event executes when GNU social encounters a remote URL we then decide
* to interrogate for metadata. oEmbed gloms onto it to see if we have an
* oEmbed endpoint or image to try to represent in the post.
*
* @param $url string the remote URL we're looking at
* @param $dom DOMDocument the document we're getting metadata from
* @param $metadata stdClass class representing the metadata
* @return bool true if successful, the exception object if it isn't.
*/
public function onGetRemoteUrlMetadataFromDom($url, DOMDocument $dom, stdClass &$metadata)
{
try {
@@ -48,20 +108,20 @@ class OembedPlugin extends Plugin
'maxheight' => common_config('thumbnail', 'height'),
);
$metadata = oEmbedHelper::getOembedFrom($api, $url, $params);
// Facebook just gives us javascript in its oembed html,
// Facebook just gives us javascript in its oembed html,
// so use the content of the title element instead
if(strpos($url,'https://www.facebook.com/') === 0) {
$metadata->html = @$dom->getElementsByTagName('title')->item(0)->nodeValue;
if (strpos($url, 'https://www.facebook.com/') === 0) {
$metadata->html = @$dom->getElementsByTagName('title')->item(0)->nodeValue;
}
// Wordpress sometimes also just gives us javascript, use og:description if it is available
$xpath = new DomXpath($dom);
$generatorNode = @$xpath->query('//meta[@name="generator"][1]')->item(0);
if ($generatorNode instanceof DomElement) {
// when wordpress only gives us javascript, the html stripped from tags
// is the same as the title, so this helps us to identify this (common) case
if(strpos($generatorNode->getAttribute('content'),'WordPress') === 0
if (strpos($generatorNode->getAttribute('content'), 'WordPress') === 0
&& trim(strip_tags($metadata->html)) == trim($metadata->title)) {
$propertyNode = @$xpath->query('//meta[@property="og:description"][1]')->item(0);
if ($propertyNode instanceof DomElement) {
@@ -70,6 +130,7 @@ class OembedPlugin extends Plugin
}
}
} catch (Exception $e) {
// FIXME - make sure the error was because we couldn't get metadata, not something else! -mb
common_log(LOG_INFO, 'Could not find an oEmbed endpoint using link headers, trying OpenGraph from HTML.');
// Just ignore it!
$metadata = OpenGraphHelper::ogFromHtml($dom);
@@ -79,41 +140,49 @@ class OembedPlugin extends Plugin
// sometimes sites serve the path, not the full URL, for images
// let's "be liberal in what you accept from others"!
// add protocol and host if the thumbnail_url starts with /
if(substr($metadata->thumbnail_url,0,1) == '/') {
if (substr($metadata->thumbnail_url, 0, 1) == '/') {
$thumbnail_url_parsed = parse_url($metadata->url);
$metadata->thumbnail_url = $thumbnail_url_parsed['scheme']."://".$thumbnail_url_parsed['host'].$metadata->thumbnail_url;
}
// some wordpress opengraph implementations sometimes return a white blank image
// no need for us to save that!
if($metadata->thumbnail_url == 'https://s0.wp.com/i/blank.jpg') {
if ($metadata->thumbnail_url == 'https://s0.wp.com/i/blank.jpg') {
unset($metadata->thumbnail_url);
}
}
// FIXME: this is also true of locally-installed wordpress so we should watch out for that.
}
return true;
}
public function onEndShowHeadElements(Action $action)
{
switch ($action->getActionName()) {
case 'attachment':
$action->element('link',array('rel'=>'alternate',
$action->element('link', array('rel'=>'alternate',
'type'=>'application/json+oembed',
'href'=>common_local_url(
'oembed',
array(),
array('format'=>'json', 'url'=>
common_local_url('attachment',
array('attachment' => $action->attachment->getID())))),
common_local_url(
'attachment',
array('attachment' => $action->attachment->getID())
))
),
'title'=>'oEmbed'));
$action->element('link',array('rel'=>'alternate',
$action->element('link', array('rel'=>'alternate',
'type'=>'text/xml+oembed',
'href'=>common_local_url(
'oembed',
array(),
array('format'=>'xml','url'=>
common_local_url('attachment',
array('attachment' => $action->attachment->getID())))),
common_local_url(
'attachment',
array('attachment' => $action->attachment->getID())
))
),
'title'=>'oEmbed'));
break;
case 'shownotice':
@@ -121,19 +190,21 @@ class OembedPlugin extends Plugin
break;
}
try {
$action->element('link',array('rel'=>'alternate',
$action->element('link', array('rel'=>'alternate',
'type'=>'application/json+oembed',
'href'=>common_local_url(
'oembed',
array(),
array('format'=>'json','url'=>$action->notice->getUrl())),
array('format'=>'json','url'=>$action->notice->getUrl())
),
'title'=>'oEmbed'));
$action->element('link',array('rel'=>'alternate',
$action->element('link', array('rel'=>'alternate',
'type'=>'text/xml+oembed',
'href'=>common_local_url(
'oembed',
array(),
array('format'=>'xml','url'=>$action->notice->getUrl())),
array('format'=>'xml','url'=>$action->notice->getUrl())
),
'title'=>'oEmbed'));
} catch (InvalidUrlException $e) {
// The notice is probably a share or similar, which don't
@@ -145,7 +216,8 @@ class OembedPlugin extends Plugin
return true;
}
public function onEndShowStylesheets(Action $action) {
public function onEndShowStylesheets(Action $action)
{
$action->cssLink($this->path('css/oembed.css'));
return true;
}
@@ -170,7 +242,6 @@ class OembedPlugin extends Plugin
if (isset($file->mimetype)
&& (('text/html' === substr($file->mimetype, 0, 9)
|| 'application/xhtml+xml' === substr($file->mimetype, 0, 21)))) {
try {
$oembed_data = File_oembed::_getOembed($file->url);
if ($oembed_data === false) {
@@ -199,9 +270,12 @@ class OembedPlugin extends Plugin
if (empty($oembed->author_url)) {
$out->text($oembed->author_name);
} else {
$out->element('a', array('href' => $oembed->author_url,
$out->element(
'a',
array('href' => $oembed->author_url,
'class' => 'url'),
$oembed->author_name);
$oembed->author_name
);
}
}
if (!empty($oembed->provider)) {
@@ -209,9 +283,12 @@ class OembedPlugin extends Plugin
if (empty($oembed->provider_url)) {
$out->text($oembed->provider);
} else {
$out->element('a', array('href' => $oembed->provider_url,
$out->element(
'a',
array('href' => $oembed->provider_url,
'class' => 'url'),
$oembed->provider);
$oembed->provider
);
}
}
$out->elementEnd('div');
@@ -249,7 +326,7 @@ class OembedPlugin extends Plugin
$out->elementStart('article', ['class'=>'h-entry oembed']);
$out->elementStart('header');
try {
try {
$thumb = $file->getThumbnail(128, 128);
$out->element('img', $thumb->getHtmlAttrs(['class'=>'u-photo oembed']));
unset($thumb);
@@ -297,7 +374,7 @@ class OembedPlugin extends Plugin
return false;
}
public function onShowUnsupportedAttachmentRepresentation(HTMLOutputter $out, File $file)
{
try {
@@ -318,13 +395,23 @@ class OembedPlugin extends Plugin
$out->raw($purifier->purify($oembed->html));
}
return false;
break;
}
return true;
}
public function onCreateFileImageThumbnailSource(File $file, &$imgPath, $media=null)
/**
* This event executes when GNU social is creating a file thumbnail entry in
* the database. We glom onto this to create proper information for oEmbed
* object thumbnails.
*
* @param $file File the file of the created thumbnail
* @param &$imgPath string = the path to the created thumbnail
* @return bool true if it succeeds (including non-action
* states where it isn't oEmbed data, so it doesn't mess up the event handle
* for other things hooked into it), or the exception if it fails.
*/
public function onCreateFileImageThumbnailSource(File $file, &$imgPath)
{
// If we are on a private node, we won't do any remote calls (just as a precaution until
// we can configure this from config.php for the private nodes)
@@ -341,8 +428,7 @@ class OembedPlugin extends Plugin
try {
// If we have proper oEmbed data, there should be an entry in the File_oembed
// and File_thumbnail tables respectively. If not, we're not going to do anything.
$file_oembed = File_oembed::getByFile($file);
$thumbnail = File_thumbnail::byFile($file);
$thumbnail = File_thumbnail::byFile($file);
} catch (NoResultException $e) {
// Not Oembed data, or at least nothing we either can or want to use.
common_debug('No oEmbed data found for file id=='.$file->getID());
@@ -364,7 +450,7 @@ class OembedPlugin extends Plugin
}
/**
* @return boolean false on no check made, provider name on success
* @return bool false on no check made, provider name on success
* @throws ServerException if check is made but fails
*/
protected function checkWhitelist($url)
@@ -383,79 +469,157 @@ class OembedPlugin extends Plugin
throw new ServerException(sprintf(_('Domain not in remote thumbnail source whitelist: %s'), $host));
}
/**
* Check the file size of a remote file using a HEAD request and checking
* the content-length variable returned. This isn't 100% foolproof but is
* reliable enough for our purposes.
*
* @return string|bool the file size if it succeeds, false otherwise.
*/
private function getRemoteFileSize($url)
{
try {
if (empty($url)) {
return false;
}
stream_context_set_default(array('http' => array('method' => 'HEAD')));
$head = @get_headers($url, 1);
if (gettype($head)=="array") {
$head = array_change_key_case($head);
$size = isset($head['content-length']) ? $head['content-length'] : 0;
if (!$size) {
return false;
}
} else {
return false;
}
return $size; // return formatted size
} catch (Exception $err) {
common_log(LOG_ERR, __CLASS__.': getRemoteFileSize on URL : '._ve($url).' threw exception: '.$err->getMessage());
return false;
}
}
/**
* A private helper function that uses a CURL lookup to check the mime type
* of a remote URL to see it it's an image.
*
* @return bool true if the remote URL is an image, or false otherwise.
*/
private function isRemoteImage($url)
{
if (!filter_var($url, FILTER_VALIDATE_URL)) {
common_log(LOG_ERR, "Invalid URL in OEmbed::isRemoteImage()");
return false;
}
if ($url==null) {
common_log(LOG_ERR, "URL not specified in OEmbed::isRemoteImage()");
return false;
}
try {
$curl = curl_init($url);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_HEADER, true);
curl_setopt($curl, CURLOPT_NOBODY, true);
curl_exec($curl);
$type = curl_getinfo($curl, CURLINFO_CONTENT_TYPE);
if (strpos($type, 'image') !== false) {
return true;
} else {
return false;
}
} finally {
return false;
}
}
/**
* Function to create and store a thumbnail representation of a remote image
*
* @param $thumbnail File_thumbnail object containing the file thumbnail
* @return bool true if it succeeded, the exception if it fails, or false if it
* is limited by system limits (ie the file is too large.)
*/
protected function storeRemoteFileThumbnail(File_thumbnail $thumbnail)
{
if (!empty($thumbnail->filename) && file_exists($thumbnail->getPath())) {
throw new AlreadyFulfilledException(sprintf('A thumbnail seems to already exist for remote file with id==%u', $thumbnail->getFileId()));
throw new AlreadyFulfilledException(sprintf('A thumbnail seems to already exist for remote file with id==%u', $thumbnail->file_id));
}
$remoteUrl = $thumbnail->getUrl();
$this->checkWhitelist($remoteUrl);
$url = $thumbnail->getUrl();
$this->checkWhitelist($url);
$http = new HTTPClient();
// First see if it's too large for us
common_debug(__METHOD__ . ': '.sprintf('Performing HEAD request for remote file id==%u to avoid unnecessarily downloading too large files. URL: %s', $thumbnail->getFileId(), $remoteUrl));
$head = $http->head($remoteUrl);
if (!$head->isOk()) {
common_log(LOG_WARNING, 'HEAD request returned HTTP failure, so we will abort now and delete the thumbnail object.');
$thumbnail->delete();
return false;
} else {
common_debug('HEAD request returned HTTP success, so we will continue.');
}
$remoteUrl = $head->getEffectiveUrl(); // to avoid going through redirects again
$headers = $head->getHeader();
$filesize = isset($headers['content-length']) ? $headers['content-length'] : null;
// FIXME: I just copied some checks from StoreRemoteMedia, maybe we should have other checks for thumbnails? Or at least embed into some class somewhere.
if (empty($filesize)) {
// file size not specified on remote server
common_debug(sprintf('%s: Ignoring remote thumbnail because we did not get a content length for thumbnail for file id==%u', __CLASS__, $thumbnail->getFileId()));
return true;
} elseif ($filesize > common_config('attachments', 'file_quota')) {
// file too big according to site configuration
common_debug(sprintf('%s: Skip downloading remote thumbnail because content length (%u) is larger than file_quota (%u) for file id==%u', __CLASS__, intval($filesize), common_config('attachments', 'file_quota'), $thumbnail->getFileId()));
return true;
try {
$isImage = $this->isRemoteImage($url);
if ($isImage==true) {
$max_size = common_get_preferred_php_upload_limit();
$file_size = $this->getRemoteFileSize($url);
if (($file_size!=false) && ($file_size > $max_size)) {
common_debug("Went to store remote thumbnail of size " . $file_size . " but the upload limit is " . $max_size . " so we aborted.");
return false;
}
}
} catch (Exception $err) {
common_debug("Could not determine size of remote image, aborted local storage.");
return $err;
}
// Then we download the file to memory and test whether it's actually an image file
// First we download the file to memory and test whether it's actually an image file
// FIXME: To support remote video/whatever files, this needs reworking.
common_debug(sprintf('Downloading remote thumbnail for file id==%u (should be size %u) with effective URL: %s', $thumbnail->getFileId(), $filesize, _ve($remoteUrl)));
$imgData = HTTPClient::quickGet($remoteUrl);
common_debug(sprintf('Downloading remote thumbnail for file id==%u with thumbnail URL: %s', $thumbnail->file_id, $url));
$imgData = HTTPClient::quickGet($url);
$info = @getimagesizefromstring($imgData);
if ($info === false) {
throw new UnsupportedMediaException(_('Remote file format was not identified as an image.'), $remoteUrl);
throw new UnsupportedMediaException(_('Remote file format was not identified as an image.'), $url);
} elseif (!$info[0] || !$info[1]) {
throw new UnsupportedMediaException(_('Image file had impossible geometry (0 width or height)'));
}
$ext = File::guessMimeExtension($info['mime']);
$filename = sprintf('oembed-%d.%s', $thumbnail->getFileId(), $ext);
$fullpath = File_thumbnail::path($filename);
// Write the file to disk. Throw Exception on failure
if (!file_exists($fullpath) && file_put_contents($fullpath, $imgData) === false) {
throw new ServerException(_('Could not write downloaded file to disk.'));
try {
$filename = sprintf('oembed-%d.%s', $thumbnail->getFileId(), $ext);
$fullpath = File_thumbnail::path($filename);
// Write the file to disk. Throw Exception on failure
if (!file_exists($fullpath) && file_put_contents($fullpath, $imgData) === false) {
throw new ServerException(_('Could not write downloaded file to disk.'));
}
} catch (Exception $err) {
common_log(LOG_ERROR, "Went to write a thumbnail to disk in OembedPlugin::storeRemoteThumbnail but encountered error: {$err}");
return $err;
} finally {
unset($imgData);
}
// Get rid of the file from memory
unset($imgData);
// Updated our database for the file record
$orig = clone($thumbnail);
$thumbnail->filename = $filename;
$thumbnail->width = $info[0]; // array indexes documented on php.net:
$thumbnail->height = $info[1]; // https://php.net/manual/en/function.getimagesize.php
// Throws exception on failure.
$thumbnail->updateWithKeys($orig);
try {
// Updated our database for the file record
$orig = clone($thumbnail);
$thumbnail->filename = $filename;
$thumbnail->width = $info[0]; // array indexes documented on php.net:
$thumbnail->height = $info[1]; // https://php.net/manual/en/function.getimagesize.php
// Throws exception on failure.
$thumbnail->updateWithKeys($orig);
} catch (exception $err) {
common_log(LOG_ERROR, "Went to write a thumbnail entry to the database in OembedPlugin::storeRemoteThumbnail but encountered error: ".$err);
return $err;
}
return true;
}
/**
* Event raised when GNU social polls the plugin for information about it.
* Adds this plugin's version information to $versions array
*
* @param &$versions array inherited from parent
* @return bool true hook value
*/
public function onPluginVersion(array &$versions)
{
$versions[] = array('name' => 'Oembed',
'version' => self::PLUGIN_VERSION,
'author' => 'Mikael Nordfeldth',
'homepage' => 'http://gnu.io/',
'homepage' => 'http://gnu.io/social/',
'description' =>
// TRANS: Plugin description.
_m('Plugin for using and representing Oembed data.'));