Rss-Bridge/index.php
LogMANOriginal b90bcee1fc
Return exceptions in requested feed formats (#841)
* [Exceptions] Don't return header for bridge exceptions
* [Exceptions] Add link to list in exception message

This is an alternative when the button is not rendered
for some reason.

* [index] Don't return bridge exception for formats
* [index] Return feed item for bridge exceptions
* [BridgeAbstract] Rename 'getCacheTime' to 'getModifiedTime'
* [BridgeAbstract] Move caching to index.php to separate concerns

index.php needs more control over caching behavior in order to cache
exceptions. This cannot be done in a bridge, as the bridge might be
broken, thus preventing caching from working.

This also (and more importantly) separates concerns. The bridge should
not even care if caching is involved or not. Its purpose is to collect
and provide data.

Response times should be faster, as more complex bridge functions like
'setDatas' (evaluates all input parameters to predict the current
context) and 'collectData' (collects data from sites) can be skipped
entirely.

Notice: In its current form, index.php takes care of caching. This
could, however, be moved into a separate class (i.e. CacheAbstract)
in order to make implementation details cache specific.

* [index] Add '_error_time' parameter to $item['uri']

This ensures that error messages are recognized by feed readers as
new errors after 24 hours. During that time the same item is returned
no matter how often the cache is cleared.

References https://github.com/RSS-Bridge/rss-bridge/issues/814#issuecomment-420876162

* [index] Include '_error_time' in the title for errors

This prevents feed readers from "updating" feeds based on the title

* [index] Handle "HTTP_IF_MODIFIED_SINCE" client requests

Implementation is based on `BridgeAbstract::dieIfNotModified()`,
introduced in 422c125d8e and
simplified based on https://stackoverflow.com/a/10847262

Basically, before returning cached data we check if the client send
the "HTTP_IF_MODIFIED_SINCE" header. If the modification time is
more recent or equal to the cache time, we reply with "HTTP/1.1 304
 Not Modified" (same as before). Otherwise send the cached data.

* [index] Don't encode exception message with `htmlspecialchars`
* [Exceptions] Include error message in exception
* [index] Show different error message for error code 0
2018-10-15 17:21:43 +02:00

330 lines
9 KiB
PHP

<?php
/*
Create a file named 'DEBUG' for enabling debug mode.
For further security, you may put whitelisted IP addresses in the file,
one IP per line. Empty file allows anyone(!).
Debugging allows displaying PHP error messages and bypasses the cache: this
can allow a malicious client to retrieve data about your server and hammer
a provider throught your rss-bridge instance.
*/
if(file_exists('DEBUG')) {
$debug_whitelist = trim(file_get_contents('DEBUG'));
$debug_enabled = empty($debug_whitelist)
|| in_array($_SERVER['REMOTE_ADDR'],
explode("\n", str_replace("\r", '', $debug_whitelist)
)
);
if($debug_enabled) {
ini_set('display_errors', '1');
error_reporting(E_ALL);
define('DEBUG', true);
if (empty($debug_whitelist)) {
define('DEBUG_INSECURE', true);
}
}
}
require_once __DIR__ . '/lib/RssBridge.php';
define('PHP_VERSION_REQUIRED', '5.6.0');
// Specify directory for cached files (using FileCache)
define('CACHE_DIR', __DIR__ . '/cache');
// Specify path for whitelist file
define('WHITELIST_FILE', __DIR__ . '/whitelist.txt');
Configuration::verifyInstallation();
Configuration::loadConfiguration();
Authentication::showPromptIfNeeded();
date_default_timezone_set('UTC');
/*
Move the CLI arguments to the $_GET array, in order to be able to use
rss-bridge from the command line
*/
if (isset($argv)) {
parse_str(implode('&', array_slice($argv, 1)), $cliArgs);
$params = array_merge($_GET, $cliArgs);
} else {
$params = $_GET;
}
// FIXME : beta test UA spoofing, please report any blacklisting by PHP-fopen-unfriendly websites
$userAgent = 'Mozilla/5.0(X11; Linux x86_64; rv:30.0)';
$userAgent .= ' Gecko/20121202 Firefox/30.0(rss-bridge/0.1;';
$userAgent .= '+https://github.com/RSS-Bridge/rss-bridge)';
ini_set('user_agent', $userAgent);
// default whitelist
$whitelist_default = array(
'BandcampBridge',
'CryptomeBridge',
'DansTonChatBridge',
'DuckDuckGoBridge',
'FacebookBridge',
'FlickrExploreBridge',
'GooglePlusPostBridge',
'GoogleSearchBridge',
'IdenticaBridge',
'InstagramBridge',
'OpenClassroomsBridge',
'PinterestBridge',
'ScmbBridge',
'TwitterBridge',
'WikipediaBridge',
'YoutubeBridge');
try {
Bridge::setDir(__DIR__ . '/bridges/');
Format::setDir(__DIR__ . '/formats/');
Cache::setDir(__DIR__ . '/caches/');
if(!file_exists(WHITELIST_FILE)) {
$whitelist_selection = $whitelist_default;
$whitelist_write = implode("\n", $whitelist_default);
file_put_contents(WHITELIST_FILE, $whitelist_write);
} else {
$whitelist_file_content = file_get_contents(WHITELIST_FILE);
if($whitelist_file_content != "*\n") {
$whitelist_selection = explode("\n", $whitelist_file_content);
} else {
$whitelist_selection = Bridge::listBridges();
}
// Prepare for case-insensitive match
$whitelist_selection = array_map('strtolower', $whitelist_selection);
}
$showInactive = filter_input(INPUT_GET, 'show_inactive', FILTER_VALIDATE_BOOLEAN);
$action = array_key_exists('action', $params) ? $params['action'] : null;
$bridge = array_key_exists('bridge', $params) ? $params['bridge'] : null;
// Return list of bridges as JSON formatted text
if($action === 'list') {
$list = new StdClass();
$list->bridges = array();
$list->total = 0;
foreach(Bridge::listBridges() as $bridgeName) {
$bridge = Bridge::create($bridgeName);
if($bridge === false) { // Broken bridge, show as inactive
$list->bridges[$bridgeName] = array(
'status' => 'inactive'
);
continue;
}
$status = Bridge::isWhitelisted($whitelist_selection, strtolower($bridgeName)) ? 'active' : 'inactive';
$list->bridges[$bridgeName] = array(
'status' => $status,
'uri' => $bridge->getURI(),
'name' => $bridge->getName(),
'icon' => $bridge->getIcon(),
'parameters' => $bridge->getParameters(),
'maintainer' => $bridge->getMaintainer(),
'description' => $bridge->getDescription()
);
}
$list->total = count($list->bridges);
header('Content-Type: application/json');
echo json_encode($list, JSON_PRETTY_PRINT);
} elseif($action === 'display' && !empty($bridge)) {
// DEPRECATED: 'nameBridge' scheme is replaced by 'name' in bridge parameter values
// this is to keep compatibility until futher complete removal
if(($pos = strpos($bridge, 'Bridge')) === (strlen($bridge) - strlen('Bridge'))) {
$bridge = substr($bridge, 0, $pos);
}
$format = $params['format']
or returnClientError('You must specify a format!');
// DEPRECATED: 'nameFormat' scheme is replaced by 'name' in format parameter values
// this is to keep compatibility until futher complete removal
if(($pos = strpos($format, 'Format')) === (strlen($format) - strlen('Format'))) {
$format = substr($format, 0, $pos);
}
// whitelist control
if(!Bridge::isWhitelisted($whitelist_selection, strtolower($bridge))) {
throw new \HttpException('This bridge is not whitelisted', 401);
die;
}
// Data retrieval
$bridge = Bridge::create($bridge);
$noproxy = array_key_exists('_noproxy', $params) && filter_var($params['_noproxy'], FILTER_VALIDATE_BOOLEAN);
if(defined('PROXY_URL') && PROXY_BYBRIDGE && $noproxy) {
define('NOPROXY', true);
}
// Cache timeout
$cache_timeout = -1;
if(array_key_exists('_cache_timeout', $params)) {
if(!CUSTOM_CACHE_TIMEOUT) {
throw new \HttpException('This server doesn\'t support "_cache_timeout"!');
}
$cache_timeout = filter_var($params['_cache_timeout'], FILTER_VALIDATE_INT);
} else {
$cache_timeout = $bridge->getCacheTimeout();
}
// Remove parameters that don't concern bridges
$bridge_params = array_diff_key(
$params,
array_fill_keys(
array(
'action',
'bridge',
'format',
'_noproxy',
'_cache_timeout',
), '')
);
// Remove parameters that don't concern caches
$cache_params = array_diff_key(
$params,
array_fill_keys(
array(
'action',
'format',
'_noproxy',
'_cache_timeout',
), '')
);
// Initialize cache
$cache = Cache::create('FileCache');
$cache->setPath(CACHE_DIR);
$cache->purgeCache(86400); // 24 hours
$cache->setParameters($cache_params);
$items = array();
$infos = array();
$mtime = $cache->getTime();
if($mtime !== false
&& (time() - $cache_timeout < $mtime)
&& (!defined('DEBUG') || DEBUG !== true)) { // Load cached data
// Send "Not Modified" response if client supports it
// Implementation based on https://stackoverflow.com/a/10847262
if(isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
$stime = strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']);
if($mtime <= $stime) { // Cached data is older or same
header('HTTP/1.1 304 Not Modified');
die();
}
}
$cached = $cache->loadData();
if(isset($cached['items']) && isset($cached['extraInfos'])) {
$items = $cached['items'];
$infos = $cached['extraInfos'];
}
} else { // Collect new data
try {
$bridge->setDatas($bridge_params);
$bridge->collectData();
$items = $bridge->getItems();
$infos = array(
'name' => $bridge->getName(),
'uri' => $bridge->getURI(),
'icon' => $bridge->getIcon()
);
} catch(Error $e) {
$item = array();
// Create "new" error message every 24 hours
$params['_error_time'] = urlencode((int)(time() / 86400));
// Error 0 is a special case (i.e. "trying to get property of non-object")
if($e->getCode() === 0) {
$item['title'] = 'Bridge encountered an unexpected situation! (' . $params['_error_time'] . ')';
} else {
$item['title'] = 'Bridge returned error ' . $e->getCode() . '! (' . $params['_error_time'] . ')';
}
$item['uri'] = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH) . '?' . http_build_query($params);
$item['timestamp'] = time();
$item['content'] = buildBridgeException($e, $bridge);
$items[] = $item;
} catch(Exception $e) {
$item = array();
// Create "new" error message every 24 hours
$params['_error_time'] = urlencode((int)(time() / 86400));
$item['uri'] = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH) . '?' . http_build_query($params);
$item['title'] = 'Bridge returned error ' . $e->getCode() . '! (' . $params['_error_time'] . ')';
$item['timestamp'] = time();
$item['content'] = buildBridgeException($e, $bridge);
$items[] = $item;
}
// Store data in cache
$cache->saveData(array(
'items' => $items,
'extraInfos' => $infos
));
}
// Data transformation
try {
$format = Format::create($format);
$format->setItems($items);
$format->setExtraInfos($infos);
$format->setLastModified($mtime);
$format->display();
} catch(Error $e) {
http_response_code($e->getCode());
header('Content-Type: text/html');
die(buildTransformException($e, $bridge));
} catch(Exception $e) {
http_response_code($e->getCode());
header('Content-Type: text/html');
die(buildTransformException($e, $bridge));
}
} else {
echo BridgeList::create($whitelist_selection, $showInactive);
}
} catch(HttpException $e) {
http_response_code($e->getCode());
header('Content-Type: text/plain');
die($e->getMessage());
} catch(\Exception $e) {
die($e->getMessage());
}