Basic custom CSS and theme uploading features. 'local' subdir can now be customized to a distinct directory and URL path to make it easier to separate custom themes for a multi-site farm running a common code base.

Currently only one custom theme may be uploaded per site, saved with the name 'custom' and stored into the local/themes subdirectory.
Administrators can upload a .ZIP archive containing a theme through the design admin panel; its contents are validated to ensure that only legit files are saved, and a 5M size quota is enforced.
Theme upload requires the zip extension for PHP; if not present, theme uploading is disabled by default.

Uploading and the custom CSS can be controlled via $config['theme_upload']['enabled'] and $config['custom_css']['enabled'].

Configurable directory/path/server for 'local' subdirectory (currently only as used for themes; local plugins not yet switched over)

Can set $config['local']['dir'] etc; not currently exposed in the admin panels.

Per-site directories on a separate themes server could be set up such as:
  $config['local']['dir'] = '/path/to/themes/local/' . $_nickname;
  $config['local']['server'] = 'themes.example.com';
  $config['local']['path'] = '/local/' . $_nickname;
  $config['local']['ssl'] = 'never';

6 files changed, 469 insertions, 31 deletions

diff --git a/actions/designadminpanel.php b/actions/designadminpanel.php
index 092588019..a3f2dd055 100644
--- a/actions/designadminpanel.php
+++ b/actions/designadminpanel.php
@@ -125,9 +125,19 @@ class DesignadminpanelAction extends AdminPanelAction
             return;
         }
 
-        // check for an image upload
+        // check for file uploads
 
         $bgimage = $this->saveBackgroundImage();
+        $customTheme = $this->saveCustomTheme();
+
+        $oldtheme = common_config('site', 'theme');
+        if ($customTheme) {
+            // This feels pretty hacky :D
+            $this->args['theme'] = $customTheme;
+            $themeChanged = true;
+        } else {
+            $themeChanged = ($this->trimmed('theme') != $oldtheme);
+        }
 
         static $settings = array('theme', 'logo');
 
@@ -139,15 +149,13 @@ class DesignadminpanelAction extends AdminPanelAction
 
         $this->validate($values);
 
-        $oldtheme = common_config('site', 'theme');
-
         $config = new Config();
 
         $config->query('BEGIN');
 
         // Only update colors if the theme has not changed.
 
-        if ($oldtheme == $values['theme']) {
+        if (!$themeChanged) {
 
             $bgcolor = new WebColor($this->trimmed('design_background'));
             $ccolor  = new WebColor($this->trimmed('design_content'));
@@ -189,6 +197,13 @@ class DesignadminpanelAction extends AdminPanelAction
             Config::save('design', 'backgroundimage', $bgimage);
         }
 
+        if (common_config('custom_css', 'enabled')) {
+            $css = $this->arg('css');
+            if ($css != common_config('custom_css', 'css')) {
+                Config::save('custom_css', 'css', $css);
+            }
+        }
+
         $config->query('COMMIT');
     }
 
@@ -263,6 +278,33 @@ class DesignadminpanelAction extends AdminPanelAction
     }
 
     /**
+     * Save the custom theme if the user uploaded one.
+     * 
+     * @return mixed custom theme name, if succesful, or null if no theme upload.
+     * @throws ClientException for invalid theme archives
+     * @throws ServerException if trouble saving the theme files
+     */
+
+    function saveCustomTheme()
+    {
+        if (common_config('theme_upload', 'enabled') &&
+            $_FILES['design_upload_theme']['error'] == UPLOAD_ERR_OK) {
+
+            $upload = ThemeUploader::fromUpload('design_upload_theme');
+            $basedir = common_config('local', 'dir');
+            if (empty($basedir)) {
+                $basedir = INSTALLDIR . '/local';
+            }
+            $name = 'custom'; // @todo allow multiples, custom naming?
+            $outdir = $basedir . '/theme/' . $name;
+            $upload->extract($outdir);
+            return $name;
+        } else {
+            return null;
+        }
+    }
+
+    /**
      * Attempt to validate setting values
      *
      * @return void
@@ -374,6 +416,7 @@ class DesignAdminPanelForm extends AdminForm
         $this->showTheme();
         $this->showBackground();
         $this->showColors();
+        $this->showAdvanced();
     }
 
     function showLogo()
@@ -418,6 +461,16 @@ class DesignAdminPanelForm extends AdminForm
                              false, $this->value('theme'));
         $this->unli();
 
+        if (common_config('theme_upload', 'enabled')) {
+            $this->li();
+            $this->out->element('label', array('for' => 'design_upload_theme'), _('Custom theme'));
+            $this->out->element('input', array('id' => 'design_upload_theme',
+                                               'name' => 'design_upload_theme',
+                                               'type' => 'file'));
+            $this->out->element('p', 'form_guide', _('You can upload a custom StatusNet theme as a .ZIP archive.'));
+            $this->unli();
+        }
+
         $this->out->elementEnd('ul');
 
         $this->out->elementEnd('fieldset');
@@ -502,6 +555,8 @@ class DesignAdminPanelForm extends AdminForm
 
     function showColors()
     {
+        $design = $this->out->design;
+
         $this->out->elementStart('fieldset', array('id' => 'settings_design_color'));
         $this->out->element('legend', null, _('Change colours'));
 
@@ -586,6 +641,27 @@ class DesignAdminPanelForm extends AdminForm
         $this->out->elementEnd('ul');
     }
 
+    function showAdvanced()
+    {
+        if (common_config('custom_css', 'enabled')) {
+            $this->out->elementStart('fieldset', array('id' => 'settings_design_advanced'));
+            $this->out->element('legend', null, _('Advanced'));
+            $this->out->elementStart('ul', 'form_data');
+
+            $this->li();
+            $this->out->element('label', array('for' => 'css'), _('Custom CSS'));
+            $this->out->element('textarea', array('name' => 'css',
+                                            'id' => 'css',
+                                            'cols' => '50',
+                                            'rows' => '10'),
+                                strval(common_config('custom_css', 'css')));
+            $this->unli();
+
+            $this->out->elementEnd('fieldset');
+            $this->out->elementEnd('ul');
+        }
+    }
+
     /**
      * Action elements
      *
diff --git a/lib/action.php b/lib/action.php
index c4d9fd5cb..22ea4f275 100644
--- a/lib/action.php
+++ b/lib/action.php
@@ -233,6 +233,16 @@ class Action extends HTMLOutputter // lawsuit
                 Event::handle('EndShowDesign', array($this));
             }
             Event::handle('EndShowStyles', array($this));
+            
+            if (common_config('custom_css', 'enabled')) {
+                $css = common_config('custom_css', 'css');
+                if (Event::handle('StartShowCustomCss', array($this, &$css))) {
+                    if (trim($css) != '') {
+                        $this->style($css);
+                    }
+                    Event::handle('EndShowCustomCss', array($this));
+                }
+            }
         }
     }
 
diff --git a/lib/adminpanelaction.php b/lib/adminpanelaction.php
index a927e2333..7d6a616eb 100644
--- a/lib/adminpanelaction.php
+++ b/lib/adminpanelaction.php
@@ -283,9 +283,10 @@ class AdminPanelAction extends Action
                 $this->clientError(_("Unable to delete design setting."));
                 return null;
             }
+            return $result;
         }
 
-        return $result;
+        return null;
     }
 
     function canAdmin($name)
diff --git a/lib/default.php b/lib/default.php
index 950c6018d..dcf225d1f 100644
--- a/lib/default.php
+++ b/lib/default.php
@@ -141,10 +141,17 @@ $default =
               'dir' => null,
               'path'=> null,
               'ssl' => null),
+        'theme_upload' =>
+        array('enabled' => extension_loaded('zip')),
         'javascript' =>
         array('server' => null,
               'path'=> null,
               'ssl' => null),
+        'local' => // To override path/server for themes in 'local' dir (not currently applied to local plugins)
+        array('server' => null,
+              'dir' => null,
+              'path' => null,
+              'ssl' => null),
         'throttle' =>
         array('enabled' => false, // whether to throttle edits; false by default
               'count' => 20, // number of allowed messages in timespan
@@ -260,6 +267,9 @@ $default =
               'linkcolor' => null,
               'backgroundimage' => null,
               'disposition' => null),
+        'custom_css' =>
+        array('enabled' => true,
+              'css' => ''),
         'notice' =>
         array('contentlimit' => null),
         'message' =>
diff --git a/lib/theme.php b/lib/theme.php
index 0be8c3b9d..a9d0cbc84 100644
--- a/lib/theme.php
+++ b/lib/theme.php
@@ -38,6 +38,9 @@ if (!defined('STATUSNET') && !defined('LACONICA')) {
  * Themes are directories with some expected sub-directories and files
  * in them. They're found in either local/theme (for locally-installed themes)
  * or theme/ subdir of installation dir.
+ * 
+ * Note that the 'local' directory can be overridden as $config['local']['path']
+ * and $config['local']['dir'] etc.
  *
  * This used to be a couple of functions, but for various reasons it's nice
  * to have a class instead.
@@ -76,7 +79,7 @@ class Theme
 
         if (file_exists($fulldir) && is_dir($fulldir)) {
             $this->dir  = $fulldir;
-            $this->path = common_path('local/theme/'.$name.'/');
+            $this->path = $this->relativeThemePath('local', 'local', 'theme/' . $name);
             return;
         }
 
@@ -89,42 +92,63 @@ class Theme
         if (file_exists($fulldir) && is_dir($fulldir)) {
 
             $this->dir = $fulldir;
+            $this->path = $this->relativeThemePath('theme', 'theme', $name);
+        }
+    }
 
-            $path = common_config('theme', 'path');
+    /**
+     * Build a full URL to the given theme's base directory, possibly
+     * using an offsite theme server path.
+     * 
+     * @param string $group configuration section name to pull paths from
+     * @param string $fallbackSubdir default subdirectory under INSTALLDIR
+     * @param string $name theme name
+     * 
+     * @return string URL
+     * 
+     * @todo consolidate code with that for other customizable paths
+     */
 
-            if (empty($path)) {
-                $path = common_config('site', 'path') . '/theme/';
-            }
+    protected function relativeThemePath($group, $fallbackSubdir, $name)
+    {
+        $path = common_config($group, 'path');
 
-            if ($path[strlen($path)-1] != '/') {
-                $path .= '/';
+        if (empty($path)) {
+            $path = common_config('site', 'path') . '/';
+            if ($fallbackSubdir) {
+                $path .= $fallbackSubdir . '/';
             }
+        }
 
-            if ($path[0] != '/') {
-                $path = '/'.$path;
-            }
+        if ($path[strlen($path)-1] != '/') {
+            $path .= '/';
+        }
 
-            $server = common_config('theme', 'server');
+        if ($path[0] != '/') {
+            $path = '/'.$path;
+        }
 
-            if (empty($server)) {
-                $server = common_config('site', 'server');
-            }
+        $server = common_config($group, 'server');
 
-            $ssl = common_config('theme', 'ssl');
+        if (empty($server)) {
+            $server = common_config('site', 'server');
+        }
 
-            if (is_null($ssl)) { // null -> guess
-                if (common_config('site', 'ssl') == 'always' &&
-                    !common_config('theme', 'server')) {
-                    $ssl = true;
-                } else {
-                    $ssl = false;
-                }
+        $ssl = common_config($group, 'ssl');
+
+        if (is_null($ssl)) { // null -> guess
+            if (common_config('site', 'ssl') == 'always' &&
+                !common_config($group, 'server')) {
+                $ssl = true;
+            } else {
+                $ssl = false;
             }
+        }
 
-            $protocol = ($ssl) ? 'https' : 'http';
+        $protocol = ($ssl) ? 'https' : 'http';
 
-            $this->path = $protocol . '://'.$server.$path.$name;
-        }
+        $path = $protocol . '://'.$server.$path.$name;
+        return $path;
     }
 
     /**
@@ -236,7 +260,13 @@ class Theme
 
     protected static function localRoot()
     {
-        return INSTALLDIR.'/local/theme';
+        $basedir = common_config('local', 'dir');
+
+        if (empty($basedir)) {
+            $basedir = INSTALLDIR . '/local';
+        }
+
+        return $basedir . '/theme';
     }
 
     /**
diff --git a/lib/themeuploader.php b/lib/themeuploader.php
new file mode 100644
index 000000000..18ef8c4d1
--- /dev/null
+++ b/lib/themeuploader.php
@@ -0,0 +1,311 @@
+<?php
+/**
+ * StatusNet, the distributed open-source microblogging tool
+ *
+ * Utilities for theme files and paths
+ *
+ * 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  Paths
+ * @package   StatusNet
+ * @author    Brion Vibber <brion@status.net>
+ * @copyright 2010 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') && !defined('LACONICA')) {
+    exit(1);
+}
+
+/**
+ * Encapsulation of the validation-and-save process when dealing with
+ * a user-uploaded StatusNet theme archive...
+ * 
+ * @todo extract theme metadata from css/display.css
+ * @todo allow saving multiple themes
+ */
+class ThemeUploader
+{
+    protected $sourceFile;
+    protected $isUpload;
+    private $prevErrorReporting;
+
+    public function __construct($filename)
+    {
+        if (!class_exists('ZipArchive')) {
+            throw new Exception(_("This server cannot handle theme uploads without ZIP support."));
+        }
+        $this->sourceFile = $filename;
+    }
+
+    public static function fromUpload($name)
+    {
+        if (!isset($_FILES[$name]['error'])) {
+            throw new ServerException(_("Theme upload missing or failed."));
+        }
+        if ($_FILES[$name]['error'] != UPLOAD_ERR_OK) {
+            throw new ServerException(_("Theme upload missing or failed."));
+        }
+        return new ThemeUploader($_FILES[$name]['tmp_name']);
+    }
+
+    /**
+     * @param string $destDir
+     * @throws Exception on bogus files
+     */
+    public function extract($destDir)
+    {
+        $zip = $this->openArchive();
+
+        // First pass: validate but don't save anything to disk.
+        // Any errors will trip an exception.
+        $this->traverseArchive($zip);
+
+        // Second pass: now that we know we're good, actually extract!
+        $tmpDir = $destDir . '.tmp' . getmypid();
+        $this->traverseArchive($zip, $tmpDir);
+
+        $zip->close();
+
+        if (file_exists($destDir)) {
+            $killDir = $tmpDir . '.old';
+            $this->quiet();
+            $ok = rename($destDir, $killDir);
+            $this->loud();
+            if (!$ok) {
+                common_log(LOG_ERR, "Could not move old custom theme from $destDir to $killDir");
+                throw new ServerException(_("Failed saving theme."));
+            }
+        } else {
+            $killDir = false;
+        }
+
+        $this->quiet();
+        $ok = rename($tmpDir, $destDir);
+        $this->loud();
+        if (!$ok) {
+            common_log(LOG_ERR, "Could not move saved theme from $tmpDir to $destDir");
+            throw new ServerException(_("Failed saving theme."));
+        }
+
+        if ($killDir) {
+            $this->recursiveRmdir($killDir);
+        }
+    }
+
+    /**
+     * 
+     */
+    protected function traverseArchive($zip, $outdir=false)
+    {
+        $sizeLimit = 2 * 1024 * 1024; // 2 megabyte space limit?
+        $blockSize = 4096; // estimated; any entry probably takes this much space
+
+        $totalSize = 0;
+        $hasMain = false;
+        $commonBaseDir = false;
+
+        for ($i = 0; $i < $zip->numFiles; $i++) {
+            $data = $zip->statIndex($i);
+            $name = str_replace('\\', '/', $data['name']);
+
+            if (substr($name, -1) == '/') {
+                // A raw directory... skip!
+                continue;
+            }
+
+            // Check the directory structure...
+            $path = pathinfo($name);
+            $dirs = explode('/', $path['dirname']);
+            $baseDir = array_shift($dirs);
+            if ($commonBaseDir === false) {
+                $commonBaseDir = $baseDir;
+            } else {
+                if ($commonBaseDir != $baseDir) {
+                    throw new ClientException(_("Invalid theme: bad directory structure."));
+                }
+            }
+
+            foreach ($dirs as $dir) {
+                $this->validateFileOrFolder($dir);
+            }
+
+            // Is this a safe or skippable file?
+            if ($this->skippable($path['filename'], $path['extension'])) {
+                // Documentation and such... booooring
+                continue;
+            } else {
+                $this->validateFile($path['filename'], $path['extension']);
+            }
+
+            $fullPath = $dirs;
+            $fullPath[] = $path['basename'];
+            $localFile = implode('/', $fullPath);
+            if ($localFile == 'css/display.css') {
+                $hasMain = true;
+            }
+            
+            $size = $data['size'];
+            $estSize = $blockSize * max(1, intval(ceil($size / $blockSize)));
+            $totalSize += $estSize;
+            if ($totalSize > $sizeLimit) {
+                $msg = sprintf(_("Uploaded theme is too large; " .
+                                 "must be less than %d bytes uncompressed."),
+                                 $sizeLimit);
+                throw new ClientException($msg);
+            }
+
+            if ($outdir) {
+                $this->extractFile($zip, $data['name'], "$outdir/$localFile");
+            }
+        }
+
+        if (!$hasMain) {
+            throw new ClientException(_("Invalid theme archive: " .
+                                        "missing file css/display.css"));
+        }
+    }
+
+    protected function skippable($filename, $ext)
+    {
+        $skip = array('txt', 'rtf', 'doc', 'docx', 'odt');
+        if (strtolower($filename) == 'readme') {
+            return true;
+        }
+        if (in_array(strtolower($ext), $skip)) {
+            return true;
+        }
+        return false;
+    }
+
+    protected function validateFile($filename, $ext)
+    {
+        $this->validateFileOrFolder($filename);
+        $this->validateExtension($ext);
+        // @fixme validate content
+    }
+
+    protected function validateFileOrFolder($name)
+    {
+        if (!preg_match('/^[a-z0-9_-]+$/i', $name)) {
+            $msg = _("Theme contains invalid file or folder name. " .
+                     "Stick with ASCII letters, digits, underscore, and minus sign.");
+            throw new ClientException($msg);
+        }
+        return true;
+    }
+
+    protected function validateExtension($ext)
+    {
+        $allowed = array('css', 'png', 'gif', 'jpg', 'jpeg');
+        if (!in_array(strtolower($ext), $allowed)) {
+            $msg = sprintf(_("Theme contains file of type '.%s', " .
+                             "which is not allowed."),
+                           $ext);
+            throw new ClientException($msg);
+        }
+        return true;
+    }
+
+    /**
+     * @return ZipArchive
+     */
+    protected function openArchive()
+    {
+        $zip = new ZipArchive;
+        $ok = $zip->open($this->sourceFile); 
+        if ($ok !== true) {
+            common_log(LOG_ERR, "Error opening theme zip archive: " .
+                                "{$this->sourceFile} code: {$ok}");
+            throw new Exception(_("Error opening theme archive."));
+        }
+        return $zip;
+    }
+
+    /**
+     * @param ZipArchive $zip
+     * @param string $from original path inside ZIP archive
+     * @param string $to final destination path in filesystem
+     */
+    protected function extractFile($zip, $from, $to)
+    {
+        $dir = dirname($to);
+        if (!file_exists($dir)) {
+            $this->quiet();
+            $ok = mkdir($dir, 0755, true);
+            $this->loud();
+            if (!$ok) {
+                common_log(LOG_ERR, "Failed to mkdir $dir while uploading theme");
+                throw new ServerException(_("Failed saving theme."));
+            }
+        } else if (!is_dir($dir)) {
+            common_log(LOG_ERR, "Output directory $dir not a directory while uploading theme");
+            throw new ServerException(_("Failed saving theme."));
+        }
+
+        // ZipArchive::extractTo would be easier, but won't let us alter
+        // the directory structure.
+        $in = $zip->getStream($from);
+        if (!$in) {
+            common_log(LOG_ERR, "Couldn't open archived file $from while uploading theme");
+            throw new ServerException(_("Failed saving theme."));
+        }
+        $this->quiet();
+        $out = fopen($to, "wb");
+        $this->loud();
+        if (!$out) {
+            common_log(LOG_ERR, "Couldn't open output file $to while uploading theme");
+            throw new ServerException(_("Failed saving theme."));
+        }
+        while (!feof($in)) {
+            $buffer = fread($in, 65536);
+            fwrite($out, $buffer);
+        }
+        fclose($in);
+        fclose($out);
+    }
+
+    private function quiet()
+    {
+        $this->prevErrorReporting = error_reporting();
+        error_reporting($this->prevErrorReporting & ~E_WARNING);
+    }
+
+    private function loud()
+    {
+        error_reporting($this->prevErrorReporting);
+    }
+
+    private function recursiveRmdir($dir)
+    {
+        $list = dir($dir);
+        while (($file = $list->read()) !== false) {
+            if ($file == '.' || $file == '..') {
+                continue;
+            }
+            $full = "$dir/$file";
+            if (is_dir($full)) {
+                $this->recursiveRmdir($full);
+            } else {
+                unlink($full);
+            }
+        }
+        $list->close();
+        rmdir($dir);
+    }
+
+}