First steps on converting FeedSub into the pub/sub basis for OStatus communications:

* renamed FeedSub plugin to OStatus
* now setting avatar on subscriptions
* general fixes for subscription
* integrated PuSH hub to handle only user timelines on canonical ID url; sends updates directly
* set $config['feedsub']['nohub'] = true to test w/ foreign feeds that don't have hubs (won't actually receive updates though)
* a few bits of code documentation
* HMAC support for verified distributions (safest if sub setup is on HTTPS)

And a couple core changes:
* minimizing HTML output for exceptions in API requests to aid in debugging
* fix for rel=self link in apitimelineuser when id given

This does not not yet include any of the individual subscription management (Salmon notifications for sub/unsub, etc) nor a nice UI for user subscriptions.
Needs some further cleanup to treat posts as status updates instead of link references.

3 files changed, 539 insertions, 0 deletions

diff --git a/plugins/OStatus/actions/feedsubcallback.php b/plugins/OStatus/actions/feedsubcallback.php
new file mode 100644
index 000000000..c57ea5b10
--- /dev/null
+++ b/plugins/OStatus/actions/feedsubcallback.php
@@ -0,0 +1,105 @@
+<?php
+/*
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2009, StatusNet, Inc.
+ *
+ * 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/>.
+ */
+
+/**
+ * @package FeedSubPlugin
+ * @maintainer Brion Vibber <brion@status.net>
+ */
+
+if (!defined('STATUSNET') && !defined('LACONICA')) { exit(1); }
+
+
+class FeedSubCallbackAction extends Action
+{
+    function handle()
+    {
+        parent::handle();
+        if ($_SERVER['REQUEST_METHOD'] == 'POST') {
+            $this->handlePost();
+        } else {
+            $this->handleGet();
+        }
+    }
+    
+    /**
+     * Handler for POST content updates from the hub
+     */
+    function handlePost()
+    {
+        $feedid = $this->arg('feed');
+        common_log(LOG_INFO, "POST for feed id $feedid");
+        if (!$feedid) {
+            throw new ServerException('Empty or invalid feed id', 400);
+        }
+
+        $feedinfo = Feedinfo::staticGet('id', $feedid);
+        if (!$feedinfo) {
+            throw new ServerException('Unknown feed id ' . $feedid, 400);
+        }
+
+        $hmac = '';
+        if (isset($_SERVER['HTTP_X_HUB_SIGNATURE'])) {
+            $hmac = $_SERVER['HTTP_X_HUB_SIGNATURE'];
+        }
+
+        $post = file_get_contents('php://input');
+        $feedinfo->postUpdates($post, $hmac);
+    }
+    
+    /**
+     * Handler for GET verification requests from the hub
+     */
+    function handleGet()
+    {
+        $mode = $this->arg('hub_mode');
+        $topic = $this->arg('hub_topic');
+        $challenge = $this->arg('hub_challenge');
+        $lease_seconds = $this->arg('hub_lease_seconds');
+        $verify_token = $this->arg('hub_verify_token');
+        
+        if ($mode != 'subscribe' && $mode != 'unsubscribe') {
+            common_log(LOG_WARNING, __METHOD__ . ": bogus hub callback with mode \"$mode\"");
+            throw new ServerException("Bogus hub callback: bad mode", 404);
+        }
+        
+        $feedinfo = Feedinfo::staticGet('feeduri', $topic);
+        if (!$feedinfo) {
+            common_log(LOG_WARNING, __METHOD__ . ": bogus hub callback for unknown feed $topic");
+            throw new ServerException("Bogus hub callback: unknown feed", 404);
+        }
+
+        # Can't currently set the token in our sub api
+        #if ($feedinfo->verify_token !== $verify_token) {
+        #    common_log(LOG_WARNING, __METHOD__ . ": bogus hub callback with bad token \"$verify_token\" for feed $topic");
+        #    throw new ServerError("Bogus hub callback: bad token", 404);
+        #}
+        
+        // OK!
+        common_log(LOG_INFO, __METHOD__ . ': sub confirmed');
+        $feedinfo->sub_start = common_sql_date(time());
+        if ($lease_seconds > 0) {
+            $feedinfo->sub_end = common_sql_date(time() + $lease_seconds);
+        } else {
+            $feedinfo->sub_end = null;
+        }
+        $feedinfo->update();
+        
+        print $challenge;
+    }
+}
diff --git a/plugins/OStatus/actions/feedsubsettings.php b/plugins/OStatus/actions/feedsubsettings.php
new file mode 100644
index 000000000..4d5b7b60f
--- /dev/null
+++ b/plugins/OStatus/actions/feedsubsettings.php
@@ -0,0 +1,258 @@
+<?php
+/*
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2009, StatusNet, Inc.
+ *
+ * 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/>.
+ */
+
+/**
+ * @package FeedSubPlugin
+ * @maintainer Brion Vibber <brion@status.net>
+ */
+
+if (!defined('STATUSNET') && !defined('LACONICA')) { exit(1); }
+
+class FeedSubSettingsAction extends ConnectSettingsAction
+{
+    protected $feedurl;
+    protected $preview;
+    protected $munger;
+
+    /**
+     * Title of the page
+     *
+     * @return string Title of the page
+     */
+
+    function title()
+    {
+        return _m('Feed subscriptions');
+    }
+
+    /**
+     * Instructions for use
+     *
+     * @return instructions for use
+     */
+
+    function getInstructions()
+    {
+        return _m('You can subscribe to feeds from other sites; ' .
+                  'updates will appear in your personal timeline.');
+    }
+
+    /**
+     * Content area of the page
+     *
+     * Shows a form for associating a Twitter account with this
+     * StatusNet account. Also lets the user set preferences.
+     *
+     * @return void
+     */
+
+    function showContent()
+    {
+        $user = common_current_user();
+
+        $profile = $user->getProfile();
+
+        $fuser = null;
+
+        $flink = Foreign_link::getByUserID($user->id, FEEDSUB_SERVICE);
+
+        if (!empty($flink)) {
+            $fuser = $flink->getForeignUser();
+        }
+
+        $this->elementStart('form', array('method' => 'post',
+                                          'id' => 'form_settings_feedsub',
+                                          'class' => 'form_settings',
+                                          'action' =>
+                                          common_local_url('feedsubsettings')));
+
+        $this->hidden('token', common_session_token());
+
+        $this->elementStart('fieldset', array('id' => 'settings_feeds'));
+
+        $this->elementStart('ul', 'form_data');
+        $this->elementStart('li', array('id' => 'settings_twitter_login_button'));
+        $this->input('feedurl', _('Feed URL'), $this->feedurl, _('Enter the URL of a PubSubHubbub-enabled feed'));
+        $this->elementEnd('li');
+        $this->elementEnd('ul');
+
+        if ($this->preview) {
+            $this->submit('subscribe', _m('Subscribe'));
+        } else {
+            $this->submit('validate', _m('Continue'));
+        }
+
+        $this->elementEnd('fieldset');
+
+        $this->elementEnd('form');
+
+        if ($this->preview) {
+            $this->previewFeed();
+        }
+    }
+
+    /**
+     * Handle posts to this form
+     *
+     * Based on the button that was pressed, muxes out to other functions
+     * to do the actual task requested.
+     *
+     * All sub-functions reload the form with a message -- success or failure.
+     *
+     * @return void
+     */
+
+    function handlePost()
+    {
+        // CSRF protection
+        $token = $this->trimmed('token');
+        if (!$token || $token != common_session_token()) {
+            $this->showForm(_('There was a problem with your session token. '.
+                              'Try again, please.'));
+            return;
+        }
+
+        if ($this->arg('validate')) {
+            $this->validateAndPreview();
+        } else if ($this->arg('subscribe')) {
+            $this->saveFeed();
+        } else {
+            $this->showForm(_('Unexpected form submission.'));
+        }
+    }
+
+    /**
+     * Set up and add a feed
+     *
+     * @return boolean true if feed successfully read
+     * Sends you back to input form if not.
+     */
+    function validateFeed()
+    {
+        $feedurl = trim($this->arg('feedurl'));
+        
+        if ($feedurl == '') {
+            $this->showForm(_m('Empty feed URL!'));
+            return;
+        }
+        $this->feedurl = $feedurl;
+        
+        // Get the canonical feed URI and check it
+        try {
+            $discover = new FeedDiscovery();
+            $uri = $discover->discoverFromURL($feedurl);
+        } catch (FeedSubBadURLException $e) {
+            $this->showForm(_m('Invalid URL or could not reach server.'));
+            return false;
+        } catch (FeedSubBadResponseException $e) {
+            $this->showForm(_m('Cannot read feed; server returned error.'));
+            return false;
+        } catch (FeedSubEmptyException $e) {
+            $this->showForm(_m('Cannot read feed; server returned an empty page.'));
+            return false;
+        } catch (FeedSubBadHTMLException $e) {
+            $this->showForm(_m('Bad HTML, could not find feed link.'));
+            return false;
+        } catch (FeedSubNoFeedException $e) {
+            $this->showForm(_m('Could not find a feed linked from this URL.'));
+            return false;
+        } catch (FeedSubUnrecognizedTypeException $e) {
+            $this->showForm(_m('Not a recognized feed type.'));
+            return false;
+        } catch (FeedSubException $e) {
+            // Any new ones we forgot about
+            $this->showForm(_m('Bad feed URL.'));
+            return false;
+        }
+        
+        $this->munger = $discover->feedMunger();
+        $this->feedinfo = $this->munger->feedInfo();
+
+        if ($this->feedinfo->huburi == '' && !common_config('feedsub', 'nohub')) {
+            $this->showForm(_m('Feed is not PuSH-enabled; cannot subscribe.'));
+            return false;
+        }
+        
+        return true;
+    }
+
+    function saveFeed()
+    {
+        if ($this->validateFeed()) {
+            $this->preview = true;
+            $this->feedinfo = Feedinfo::ensureProfile($this->munger);
+
+            // If not already in use, subscribe to updates via the hub
+            if ($this->feedinfo->sub_start) {
+                common_log(LOG_INFO, __METHOD__ . ": double the fun! new sub for {$this->feedinfo->feeduri} last subbed {$this->feedinfo->sub_start}");
+            } else {
+                $ok = $this->feedinfo->subscribe();
+                common_log(LOG_INFO, __METHOD__ . ": sub was $ok");
+                if (!$ok) {
+                    $this->showForm(_m('Feed subscription failed! Bad response from hub.'));
+                    return;
+                }
+            }
+            
+            // And subscribe the current user to the local profile
+            $user = common_current_user();
+            $profile = $this->feedinfo->getProfile();
+            if (!$profile) {
+                throw new ServerException("Feed profile was not saved properly.");
+            }
+
+            if ($user->isSubscribed($profile)) {
+                $this->showForm(_m('Already subscribed!'));
+            } elseif ($user->subscribeTo($profile)) {
+                $this->showForm(_m('Feed subscribed!'));
+            } else {
+                $this->showForm(_m('Feed subscription failed!'));
+            }
+        }
+    }
+
+    function validateAndPreview()
+    {
+        if ($this->validateFeed()) {
+            $this->preview = true;
+            $this->showForm(_m('Previewing feed:'));
+        }
+    }
+
+    function previewFeed()
+    {
+        $feedinfo = $this->munger->feedinfo();
+        $notice = $this->munger->notice(0, true); // preview
+
+        if ($notice) {
+            $this->element('b', null, 'Preview of latest post from this feed:');
+
+            $item = new NoticeList($notice, $this);
+            $item->show();
+        } else {
+            $this->element('b', null, 'No posts in this feed yet.');
+        }
+    }
+
+    function showScripts()
+    {
+        parent::showScripts();
+        $this->autofocus('feedurl');
+    }
+}
diff --git a/plugins/OStatus/actions/hub.php b/plugins/OStatus/actions/hub.php
new file mode 100644
index 000000000..5caf4b48e
--- /dev/null
+++ b/plugins/OStatus/actions/hub.php
@@ -0,0 +1,176 @@
+<?php
+/*
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Integrated PuSH hub; lets us only ping them what need it.
+ * @package Hub
+ * @maintainer Brion Vibber <brion@status.net>
+ */
+
+/**
+
+
+Things to consider...
+* should we purge incomplete subscriptions that never get a verification pingback?
+* when can we send subscription renewal checks?
+    - at next send time probably ok
+* when can we handle trimming of subscriptions?
+    - at next send time probably ok
+* should we keep a fail count?
+
+*/
+
+
+class HubAction extends Action
+{
+    function arg($arg, $def=null)
+    {
+        // PHP converts '.'s in incoming var names to '_'s.
+        // It also merges multiple values, which'll break hub.verify and hub.topic for publishing
+        // @fixme handle multiple args
+        $arg = str_replace('.', '_', $arg);
+        return parent::arg($arg, $def);
+    }
+
+    function prepare($args)
+    {
+        StatusNet::setApi(true); // reduce exception reports to aid in debugging
+        return parent::prepare($args);
+    }
+
+    function handle()
+    {
+        $mode = $this->trimmed('hub.mode');
+        switch ($mode) {
+        case "subscribe":
+            $this->subscribe();
+            break;
+        case "unsubscribe":
+            $this->unsubscribe();
+            break;
+        case "publish":
+            throw new ServerException("Publishing outside feeds not supported.", 400);
+        default:
+            throw new ServerException("Unrecognized mode '$mode'.", 400);
+        }
+    }
+
+    /**
+     * Process a PuSH feed subscription request.
+     *
+     * HTTP return codes:
+     *   202 Accepted - request saved and awaiting verification
+     *   204 No Content - already subscribed
+     *   403 Forbidden - rejecting this (not specifically spec'd)
+     */
+    function subscribe()
+    {
+        $feed = $this->argUrl('hub.topic');
+        $callback = $this->argUrl('hub.callback');
+
+        common_log(LOG_DEBUG, __METHOD__ . ": checking sub'd to $feed $callback");
+        if ($this->getSub($feed, $callback)) {
+            // Already subscribed; return 204 per spec.
+            header('HTTP/1.1 204 No Content');
+            common_log(LOG_DEBUG, __METHOD__ . ': already subscribed');
+            return;
+        }
+
+        common_log(LOG_DEBUG, __METHOD__ . ': setting up');
+        $sub = new HubSub();
+        $sub->topic = $feed;
+        $sub->callback = $callback;
+        $sub->secret = $this->arg('hub.secret', null);
+        $sub->setLease(intval($this->arg('hub.lease_seconds')));
+
+        // @fixme check for feeds we don't manage
+        // @fixme check the verification mode, might want a return immediately?
+
+        common_log(LOG_DEBUG, __METHOD__ . ': inserting');
+        $ok = $sub->insert();
+        
+        if (!$ok) {
+            throw new ServerException("Failed to save subscription record", 500);
+        }
+
+        // @fixme check errors ;)
+
+        $data = array('sub' => $sub, 'mode' => 'subscribe');
+        $qm = QueueManager::get();
+        $qm->enqueue($data, 'hubverify');
+        
+        header('HTTP/1.1 202 Accepted');
+        common_log(LOG_DEBUG, __METHOD__ . ': done');
+    }
+
+    /**
+     * Process a PuSH feed unsubscription request.
+     *
+     * HTTP return codes:
+     *   202 Accepted - request saved and awaiting verification
+     *   204 No Content - already subscribed
+     *   400 Bad Request - invalid params or rejected feed
+     */
+    function unsubscribe()
+    {
+        $feed = $this->argUrl('hub.topic');
+        $callback = $this->argUrl('hub.callback');
+        $sub = $this->getSub($feed, $callback);
+        
+        if ($sub) {
+            if ($sub->verify('unsubscribe')) {
+                $sub->delete();
+                common_log(LOG_INFO, "PuSH unsubscribed $feed for $callback");
+            } else {
+                throw new ServerException("Failed PuSH unsubscription: verification failed! $feed for $callback");
+            }
+        } else {
+            throw new ServerException("Failed PuSH unsubscription: not subscribed! $feed for $callback");
+        }
+    }
+
+    /**
+     * Grab and validate a URL from POST parameters.
+     * @throws ServerException for malformed or non-http/https URLs
+     */
+    protected function argUrl($arg)
+    {
+        $url = $this->arg($arg);
+        $params = array('domain_check' => false, // otherwise breaks my local tests :P
+                        'allowed_schemes' => array('http', 'https'));
+        if (Validate::uri($url, $params)) {
+            return $url;
+        } else {
+            throw new ServerException("Invalid URL passed for $arg: '$url'", 400);
+        }
+    }
+
+    /**
+     * Get HubSub subscription record for a given feed & subscriber.
+     *
+     * @param string $feed
+     * @param string $callback
+     * @return mixed HubSub or false
+     */
+    protected function getSub($feed, $callback)
+    {
+        return HubSub::staticGet($feed, $callback);
+    }
+}
+