{

/**

* HTTP request object that's used to do the requests

*

* @var HTTP_Request2

*/

protected $request;

/**

* Debug mode

* If activated, the response object will contain the HTTP Response

*

* @var boolean

*/

protected $debug = false;

/**

* Full response of the linkback request, helpful for debugging

* in some error conditions.

* Gets set when $debug is enabled

*

* @var \HTTP_Request2_Response

*/

protected $debugResponse;

/**

* URL validation helper

*

* @var Url

*/

protected $urlValidator;

/**

* Initialize URL validator

*/

public function __construct()

{

$this->urlValidator = new Url();

}

/**

* Send a linkback (webmention or pingback), indicating a link from

* source to target.

* The target's linkback server will be discovered automatically.

*

* @param string $sourceUri URL on this side, it links to $targetUri

* @param string $targetUri Remote URL that shall be notified about source

*

* @return Response\Ping Pingback response object containing all error

* and status information.

*/

public function send($sourceUri, $targetUri)

{

$this->debugResponse = null;

if (!$this->urlValidator->validate($sourceUri)) {

return new Response\Ping(

'Source URI invalid: ' . $sourceUri,

States::INVALID_URI

);

}

if (!$this->urlValidator->validate($targetUri)) {

return new Response\Ping(

'Target URI invalid: ' . $targetUri,

States::INVALID_URI

);

}

$serverInfo = $this->discoverServer($targetUri);

if ($serverInfo instanceof Response\Ping) {

if ($this->debug) {

$serverInfo->setResponse($this->debugResponse);

}

return $serverInfo;

}

if ($serverInfo->type == 'pingback') {

return $this->sendPingback($serverInfo, $sourceUri, $targetUri);

}

return $this->sendWebmention($serverInfo, $sourceUri, $targetUri);

}

/**

* Autodiscover the linkback server for the given URI.

*

* @param string $targetUri Some URL to discover the linkback server of

*

* @return Server\Info|Response\Ping Server info on success, Ping response object

* on failure. Response object has debug

* response not set.

*/

public function discoverServer($targetUri)

{

//at first, try a HEAD request that does not transfer so much data

$req = $this->getRequest();

$req->setUrl($targetUri);

$req->setMethod(HTTP_Request2::METHOD_HEAD);

$res = $req->send();

if ($this->debug) {

$this->debugResponse = $res;

}

if (intval($res->getStatus() / 100) > 3

&& $res->getStatus() != 405 //method not supported/allowed

) {

return new Response\Ping(

'Error fetching target URI via HEAD', States::TARGET_URI_NOT_FOUND

);

}

$uTarget = new \Net_URL2($targetUri);

$info = $this->extractHeader($res, 'HEAD', $uTarget);

if ($info !== null) {

return $info;

}

list($type) = explode(';', $res->getHeader('Content-type'));

if ($type != 'text/html' && $type != 'text/xml'

&& $type != 'application/xhtml+xml'

&& $res->getStatus() != 405//method not allowed

) {

return new Response\Ping(

'No linkback server found for URI (HEAD only)',

States::PINGBACK_UNSUPPORTED

);

}

//HEAD failed, do a normal GET

$req->setMethod(HTTP_Request2::METHOD_GET);

$res = $req->send();

if ($this->debug) {

$this->debugResponse = $res;

}

if (intval($res->getStatus() / 100) > 3) {

return new Response\Ping(

'Error fetching target URI', States::TARGET_URI_NOT_FOUND

);

}

//yes, maybe the server does return this header now

// e.g. PHP's Phar::webPhar() does not work with HEAD

// https://bugs.php.net/bug.php?id=51918

$info = $this->extractHeader($res, 'GET', $uTarget);

if ($info !== null) {

return $info;

}

$body = $res->getBody();

$doc = DomLoader::load($body, $res);

$xpath = new \DOMXPath($doc);

$xpath->registerNamespace('h', 'http://www.w3.org/1999/xhtml');

$xpRel = 'concat(" ", normalize-space(@rel), " ")';

$nodeList = $xpath->query(

// <link> with rel=pingback|webmention is "body-ok" in HTML5

// https://html.spec.whatwg.org/multipage/semantics.html#body-ok

'//*[(self::link or self::h:link)'

. ' and @href'

. ' and ('

. ' contains(' . $xpRel . ', " webmention ")'

. ' or contains(' . $xpRel . ', " http://webmention.org/ ")'

. ' or @rel="pingback"'

. ')'

. ']'

// <a>

. ' | '

. '/*[self::html or self::h:html]'

. '/*[self::body or self::h:body]'

. '//*[(self::a or self::h:a)'

. ' and @href'

. ' and ('

. ' contains(' . $xpRel . ', " webmention ")'

. ' or contains(' . $xpRel . ', " http://webmention.org/ ")'

. ')'

. ']'

);

if ($nodeList->length == 0) {

//target resource is not pingback/webmention enabled

return new Response\Ping(

'No linkback server found for URI',

States::PINGBACK_UNSUPPORTED

);

}

$arLinks = array();

foreach ($nodeList as $link) {

$uri = $link->attributes->getNamedItem('href')->nodeValue;

$types = explode(

' ', $link->attributes->getNamedItem('rel')->nodeValue

);

if (array_search('http://webmention.org/', $types) !== false) {

$types[] = 'webmention';

}

if (array_search('webmention', $types) !== false

&& $this->urlValidator->relative($uri)

) {

//webmention spec allows relative URLs, pingback not

$uri = (string) $uTarget->resolve($uri);

}

if ($this->urlValidator->validate($uri)) {

foreach ($types as $type) {

if ($type == 'webmention' || $type == 'pingback') {

if (!isset($arLinks[$type])) {

$arLinks[$type] = $uri;

}

}

}

}

}

if (count($arLinks) == 0) {

return new Response\Ping(

'HTML head link server URI invalid', States::INVALID_URI

);

}

if (isset($arLinks['webmention'])) {

return new Server\Info('webmention', $arLinks['webmention']);

}

return new Server\Info('pingback', $arLinks['pingback']);

}

/**

* Extract webmention and pingback headers from the HTTP response.

* Create server info object if found

*

* @param \HTTP_Request2_Response $res HTTP response from the target

* @param string $method HTTP method used to fetch $res

* @param \Net_URL2 $url Base URL to resolve relative links

*

* @return Server\Info|Response\Ping Information about linkback endpoint

* or error information

* or NULL if no link found

*/

protected function extractHeader($res, $method, \Net_URL2 $url)

{

$http = new \HTTP2();

//webmention link header

$links = $http->parseLinks($res->getHeader('Link'));

foreach ($links as $link) {

if (isset($link['_uri']) && isset($link['rel'])

&& (array_search('webmention', $link['rel']) !== false

|| array_search('http://webmention.org/', $link['rel']) !== false)

) {

if ($this->urlValidator->relative($link['_uri'])) {

//relative URL

$link['_uri'] = (string) $url->resolve($link['_uri']);

}

if (!$this->urlValidator->validate($link['_uri'])) {

return new Response\Ping(

$method . ' Link webmention server URI invalid: '

. $link['_uri'],

States::INVALID_URI

);

}

return new Server\Info('webmention', $link['_uri']);

}

}

//pingback url header

//pingback 1.0 spec does not allow relative links

$headerUri = $res->getHeader('X-Pingback');

if ($headerUri !== null) {

if (!$this->urlValidator->validate($headerUri)) {

return new Response\Ping(

$method . ' X-Pingback server URI invalid: ' . $headerUri,

States::INVALID_URI

);

}

return new Server\Info('pingback', $headerUri);

}

return null;

}

/**

* Contacts the given pingback server and tells him that source links to

* target.

*

* @param object $serverInfo Information about the server that implements

* pingback

* @param string $sourceUri URL on this side, it links to $targetUri

* @param string $targetUri Remote URL that shall be notified about source

*

* @return Response\Ping Pingback response object containing all error

* and status information.

*/

protected function sendPingback(Server\Info $serverInfo, $sourceUri, $targetUri)

{

$encSourceUri = htmlspecialchars($sourceUri);

$encTargetUri = htmlspecialchars($targetUri);

$req = $this->getRequest();

$req->setUrl($serverInfo->uri)

->setMethod(HTTP_Request2::METHOD_POST)

->setHeader('Content-type: text/xml')

->setBody(

<<<XML

<?xml version="1.0" encoding="utf-8"?>

<methodCall>

<methodName>pingback.ping</methodName>

<params>

<param><value><string>$encSourceUri</string></value></param>

<param><value><string>$encTargetUri</string></value></param>

</params>

</methodCall>

XML

);

$res = $req->send();

$pres = new Response\Ping();

$pres->loadFromPingbackResponse($res, $this->debug);

return $pres;

}

/**

* Contacts the given webmention server and tells him that source links to

* target.

*

* @param object $serverInfo Information about the server that implements

* webmention

* @param string $sourceUri URL on this side, it links to $targetUri

* @param string $targetUri Remote URL that shall be notified about source

*

* @return Response\Ping Pingback response object containing all error

* and status information.

*/

protected function sendWebmention(

Server\Info $serverInfo, $sourceUri, $targetUri

) {

$req = $this->getRequest();

$req->setUrl($serverInfo->uri)

->setMethod(HTTP_Request2::METHOD_POST)

->setHeader('Accept: application/json;q=0.9, */*;q=0.1')

->addPostParameter('source', $sourceUri)

->addPostParameter('target', $targetUri);

$res = $req->send();

$pres = new Response\Ping();

$pres->loadFromWebmentionResponse($res, $this->debug);

return $pres;

}

//FIXME: implement http://old.aquarionics.com/misc/archives/blogite/0198.html

/**

* Enable debugging by collecting HTTP response objects.

*

* @param boolean $debug True to enable debugging, false to deactivate it.

*

* @return void

*/

public function setDebug($debug)

{

$this->debug = $debug;

}

/**

* Returns the HTTP request object clone that can be used

* for one HTTP request.

*

* @return HTTP_Request2 Clone of the setRequest() object

*/

public function getRequest()

{

if ($this->request === null) {

$request = new HTTP_Request2();

//yes, people redirect xmlrpc.php

$request->setConfig('follow_redirects', true);

//keep POST on redirect

$request->setConfig('strict_redirects', true);

$this->setRequestTemplate($request);

}

//we need to clone because previous requests could have

//set internal variables like POST data that we don't want now

return clone $this->request;

}

/**

* Sets a custom HTTP request object that will be used to do HTTP requests

*

* @param HTTP_Request2 $request Request object

*

* @return self

*/

public function setRequestTemplate(HTTP_Request2 $request)

{

$this->request = $request;

return $this;

}