gnu-social/plugins/Linkback/LinkbackPlugin.php
mmn 1be376cf87 Merge branch 'inbound-linkback' into 'master'
Accept mentions/replies/rsvps/likes via pingback and webmention

This makes the Linkback plugin bidirectional, allowing reply/mention federation between GNU Social and any pingback-enabled service (including any Wordpress site).

See merge request !41
2015-12-14 21:05:25 +00:00

392 lines
14 KiB
PHP

<?php
/**
* StatusNet, the distributed open-source microblogging tool
*
* Plugin to do linkbacks for notices containing links
*
* PHP version 5
*
* LICENCE: This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*
* @category Plugin
* @package StatusNet
* @author Evan Prodromou <evan@status.net>
* @copyright 2009 StatusNet, Inc.
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*/
if (!defined('STATUSNET')) {
exit(1);
}
require_once('Auth/Yadis/Yadis.php');
require_once(__DIR__ . '/lib/util.php');
define('LINKBACKPLUGIN_VERSION', '0.1');
/**
* Plugin to do linkbacks for notices containing URLs
*
* After new notices are saved, we check their text for URLs. If there
* are URLs, we test each URL to see if it supports any
*
* @category Plugin
* @package StatusNet
* @author Evan Prodromou <evan@status.net>
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*
* @see Event
*/
class LinkbackPlugin extends Plugin
{
var $notice = null;
function __construct()
{
parent::__construct();
}
function onHandleQueuedNotice($notice)
{
if (intval($notice->is_local) === Notice::LOCAL_PUBLIC) {
// Try to avoid actually mucking with the
// notice content
$c = $notice->content;
$this->notice = $notice;
if(!$notice->getProfile()->
getPref("linkbackplugin", "disable_linkbacks")
) {
// Ignoring results
common_replace_urls_callback($c,
array($this, 'linkbackUrl'));
}
if($notice->isRepeat()) {
$repeat = Notice::getByID($notice->repeat_of);
$this->linkbackUrl($repeat->getUrl());
} else if(!empty($notice->reply_to)) {
$parent = $notice->getParent();
$this->linkbackUrl($parent->getUrl());
}
$replyProfiles = Profile::multiGet('id', $notice->getReplies());
foreach($replyProfiles->fetchAll('profileurl') as $profileurl) {
$this->linkbackUrl($profileurl);
}
}
return true;
}
function linkbackUrl($url)
{
common_log(LOG_DEBUG,"Attempting linkback for " . $url);
$orig = $url;
$url = htmlspecialchars_decode($orig);
$scheme = parse_url($url, PHP_URL_SCHEME);
if (!in_array($scheme, array('http', 'https'))) {
return $orig;
}
// XXX: Do a HEAD first to save some time/bandwidth
$fetcher = Auth_Yadis_Yadis::getHTTPFetcher();
$result = $fetcher->get($url,
array('User-Agent: ' . $this->userAgent(),
'Accept: application/html+xml,text/html'));
if (!in_array($result->status, array('200', '206'))) {
return $orig;
}
// XXX: Should handle relative-URI resolution in these detections
$wm = $this->getWebmention($result);
if(!empty($wm)) {
// It is the webmention receiver's job to resolve source
// Ref: https://github.com/converspace/webmention/issues/43
$this->webmention($url, $wm);
} else {
$pb = $this->getPingback($result);
if (!empty($pb)) {
// Pingback still looks for exact URL in our source, so we
// must send what we have
$this->pingback($url, $pb);
} else {
$tb = $this->getTrackback($result);
if (!empty($tb)) {
$this->trackback($result->final_url, $tb);
}
}
}
return $orig;
}
// Based on https://github.com/indieweb/mention-client-php
// which is licensed Apache 2.0
function getWebmention($result) {
// XXX: the fetcher only gives back one of each header, so this may fail on multiple Link headers
if(preg_match('~<((?:https?://)?[^>]+)>; rel="webmention"~', $result->headers['Link'], $match)) {
return $match[1];
} elseif(preg_match('~<((?:https?://)?[^>]+)>; rel="http://webmention.org/?"~', $result->headers['Link'], $match)) {
return $match[1];
}
if(preg_match('/<(?:link|a)[ ]+href="([^"]+)"[ ]+rel="[^" ]* ?webmention ?[^" ]*"[ ]*\/?>/i', $result->body, $match)
|| preg_match('/<(?:link|a)[ ]+rel="[^" ]* ?webmention ?[^" ]*"[ ]+href="([^"]+)"[ ]*\/?>/i', $result->body, $match)) {
return $match[1];
} elseif(preg_match('/<(?:link|a)[ ]+href="([^"]+)"[ ]+rel="http:\/\/webmention\.org\/?"[ ]*\/?>/i', $result->body, $match)
|| preg_match('/<(?:link|a)[ ]+rel="http:\/\/webmention\.org\/?"[ ]+href="([^"]+)"[ ]*\/?>/i', $result->body, $match)) {
return $match[1];
}
}
function webmention($url, $endpoint) {
$source = $this->notice->getUrl();
$payload = array(
'source' => $source,
'target' => $url
);
$request = HTTPClient::start();
try {
$response = $request->post($endpoint,
array(
'Content-type: application/x-www-form-urlencoded',
'Accept: application/json'
),
$payload
);
if(!in_array($response->getStatus(), array(200,202))) {
common_log(LOG_WARNING,
"Webmention request failed for '$url' ($endpoint)");
}
} catch (HTTP_Request2_Exception $e) {
common_log(LOG_WARNING,
"Webmention request failed for '$url' ($endpoint)");
}
}
function getPingback($result) {
if (array_key_exists('X-Pingback', $result->headers)) {
return $result->headers['X-Pingback'];
} else if(preg_match('/<(?:link|a)[ ]+href="([^"]+)"[ ]+rel="[^" ]* ?pingback ?[^" ]*"[ ]*\/?>/i', $result->body, $match)
|| preg_match('/<(?:link|a)[ ]+rel="[^" ]* ?pingback ?[^" ]*"[ ]+href="([^"]+)"[ ]*\/?>/i', $result->body, $match)) {
return $match[1];
}
}
function pingback($url, $endpoint)
{
$args = array($this->notice->getUrl(), $url);
if (!extension_loaded('xmlrpc')) {
if (!dl('xmlrpc.so')) {
common_log(LOG_ERR, "Can't pingback; xmlrpc extension not available.");
return;
}
}
$request = HTTPClient::start();
try {
$request->setBody(xmlrpc_encode_request('pingback.ping', $args));
$response = $request->post($endpoint,
array('Content-Type: text/xml'),
false);
$response = xmlrpc_decode($response->getBody());
if (xmlrpc_is_fault($response)) {
common_log(LOG_WARNING,
"Pingback error for '$url' ($endpoint): ".
"$response[faultString] ($response[faultCode])");
} else {
common_log(LOG_INFO,
"Pingback success for '$url' ($endpoint): ".
"'$response'");
}
} catch (HTTP_Request2_Exception $e) {
common_log(LOG_WARNING,
"Pingback request failed for '$url' ($endpoint)");
}
}
// Largely cadged from trackback_cls.php by
// Ran Aroussi <ran@blogish.org>, GPL2 or any later version
// http://phptrackback.sourceforge.net/
function getTrackback($result)
{
$text = $result->body;
$url = $result->final_url;
if (preg_match_all('/(<rdf:RDF.*?<\/rdf:RDF>)/sm', $text, $match, PREG_SET_ORDER)) {
for ($i = 0; $i < count($match); $i++) {
if (preg_match('|dc:identifier="' . preg_quote($url) . '"|ms', $match[$i][1])) {
$rdf_array[] = trim($match[$i][1]);
}
}
// Loop through the RDFs array and extract trackback URIs
$tb_array = array(); // <- holds list of trackback URIs
if (!empty($rdf_array)) {
for ($i = 0; $i < count($rdf_array); $i++) {
if (preg_match('/trackback:ping="([^"]+)"/', $rdf_array[$i], $array)) {
$tb_array[] = trim($array[1]);
break;
}
}
}
// Return Trackbacks
if (empty($tb_array)) {
return null;
} else {
return $tb_array[0];
}
}
if (preg_match_all('/(<a[^>]*?rel=[\'"]trackback[\'"][^>]*?>)/', $text, $match)) {
foreach ($match[1] as $atag) {
if (preg_match('/href=[\'"]([^\'"]*?)[\'"]/', $atag, $url)) {
return $url[1];
}
}
}
return null;
}
function trackback($url, $endpoint)
{
$profile = $this->notice->getProfile();
// TRANS: Trackback title.
// TRANS: %1$s is a profile nickname, %2$s is a timestamp.
$args = array('title' => sprintf(_m('%1$s\'s status on %2$s'),
$profile->nickname,
common_exact_date($this->notice->created)),
'excerpt' => $this->notice->content,
'url' => $this->notice->getUrl(),
'blog_name' => $profile->nickname);
$fetcher = Auth_Yadis_Yadis::getHTTPFetcher();
$result = $fetcher->post($endpoint,
http_build_query($args),
array('User-Agent: ' . $this->userAgent()));
if ($result->status != '200') {
common_log(LOG_WARNING,
"Trackback error for '$url' ($endpoint): ".
"$result->body");
} else {
common_log(LOG_INFO,
"Trackback success for '$url' ($endpoint): ".
"'$result->body'");
}
}
public function onRouterInitialized(URLMapper $m)
{
$m->connect('main/linkback/webmention', array('action' => 'webmention'));
$m->connect('main/linkback/pingback', array('action' => 'pingback'));
}
public function onStartShowHTML($action)
{
header('Link: <' . common_local_url('webmention') . '>; rel="webmention"', false);
header('X-Pingback: ' . common_local_url('pingback'));
}
public function version()
{
return LINKBACKPLUGIN_VERSION;
}
function onPluginVersion(array &$versions)
{
$versions[] = array('name' => 'Linkback',
'version' => LINKBACKPLUGIN_VERSION,
'author' => 'Evan Prodromou',
'homepage' => 'http://status.net/wiki/Plugin:Linkback',
'rawdescription' =>
// TRANS: Plugin description.
_m('Notify blog authors when their posts have been linked in '.
'microblog notices using '.
'<a href="http://www.hixie.ch/specs/pingback/pingback">Pingback</a> '.
'or <a href="http://www.movabletype.org/docs/mttrackback.html">Trackback</a> protocols.'));
return true;
}
public function onStartInitializeRouter(URLMapper $m)
{
$m->connect('settings/linkback', array('action' => 'linkbacksettings'));
return true;
}
function onEndAccountSettingsNav($action)
{
$action_name = $action->trimmed('action');
$action->menuItem(common_local_url('linkbacksettings'),
// TRANS: OpenID plugin menu item on user settings page.
_m('MENU', 'Send Linkbacks'),
// TRANS: OpenID plugin tooltip for user settings menu item.
_m('Opt-out of sending linkbacks.'),
$action_name === 'linkbacksettings');
return true;
}
function onStartNoticeSourceLink($notice, &$name, &$url, &$title)
{
// If we don't handle this, keep the event handler going
if (!in_array($notice->source, array('linkback'))) {
return true;
}
try {
$url = $notice->getUrl();
// If getUrl() throws exception, $url is never set
$bits = parse_url($url);
$domain = $bits['host'];
if (substr($domain, 0, 4) == 'www.') {
$name = substr($domain, 4);
} else {
$name = $domain;
}
// TRANS: Title. %s is a domain name.
$title = sprintf(_m('Sent from %s via Linkback'), $domain);
// Abort event handler, we have a name and URL!
return false;
} catch (InvalidUrlException $e) {
// This just means we don't have the notice source data
return true;
}
}
}