← All changes | includes/class-preloader.php +125 -6 1.3.4 → 1.3.5 View file →

		@@ -35,9 +35,24 @@
35	35
36	36	public const STATE_KEY = 'xspeed_preloader_state';
37	37	public const STATE_TTL = 86400; // 24h — long enough for slow crawls.
38	38	public const CRON_HOOK = 'xspeed_preloader_tick';
39		- public const USER_AGENT = 'xSpeed-Preloader/1.0 (+cache warmer; admin-initiated)';
	39	+ /**
	40	+ * User-agent for every request the preloader makes.
	41	+ *
	42	+ * Deliberately contains no substring from the 7G/8G bad-bot lists. The
	43	+ * previous value, "xSpeed-Preloader/1.0", matched the `loader` token in
	44	+ * the alphabetical slice `(linkscan|linkwalker|loader|lwp-download|...)`
	45	+ * — a match on "Pre*loader*" — so nginx ports of 8G answered every warm
	46	+ * with 403 and newly published posts were never warmed. Upstream 8G
	47	+ * v1.5 has since dropped `loader`, but forks and vendored copies (xCloud
	48	+ * among them) still ship the older slice, so the name has to stay clear
	49	+ * of it. "Warmer" matches nothing in either list. (#481)
	50	+ *
	51	+ * Read through user_agent() rather than using this constant directly, so
	52	+ * the `xspeed_preloader_user_agent` filter applies.
	53	+ */
	54	+ public const USER_AGENT = 'xSpeed-Warmer/1.0 (+cache warmer; admin-initiated)';
40	55	public const REQUEST_TIMEOUT = 8;
41	56
42	57	/**
43	58	* Default cap on NEW remote images resolved per warmed page.
		@@ -57,8 +72,102 @@
57	72	*/
58	73	private const REMOTE_DIMENSION_LIMIT = 20;
59	74
60	75	/**
	76	+ * The user-agent every preloader request sends.
	77	+ *
	78	+ * Filterable because the blocking rule lives on the server, not here: a
	79	+ * host with its own bad-bot list can clear a warm without patching the
	80	+ * plugin or waiting for a release. An empty filter return is ignored —
	81	+ * sending no UA gets a request blocked at least as often. (#481)
	82	+ */
	83	+ public static function user_agent(): string {
	84	+ /**
	85	+ * Filter the preloader's user-agent string.
	86	+ *
	87	+ * @param string $user_agent Default self::USER_AGENT.
	88	+ */
	89	+ $ua = apply_filters( 'xspeed_preloader_user_agent', self::USER_AGENT );
	90	+
	91	+ return ( is_string( $ua ) && '' !== trim( $ua ) ) ? trim( $ua ) : self::USER_AGENT;
	92	+ }
	93	+
	94	+ /**
	95	+ * Is this status code the signature of a firewall refusing our warmer?
	96	+ *
	97	+ * 403 and 406 are what bad-bot rules (7G/8G, mod_security, Wordfence)
	98	+ * answer with. We only ever warm our OWN origin, and a page a visitor can
	99	+ * load must be loadable by us too — so these codes mean the request was
	100	+ * judged by its user-agent, not that the page is missing or broken. (#481)
	101	+ */
	102	+ private static function is_firewall_block( int $code ): bool {
	103	+ return in_array( $code, array( 403, 406 ), true );
	104	+ }
	105	+
	106	+ /**
	107	+ * Explain a warm failure in terms the admin can act on.
	108	+ *
	109	+ * A bare "HTTP 403" sent people hunting a broken page; the page is fine,
	110	+ * and the fix is a server rule, so the message has to name the cause and
	111	+ * the exact UA to allow. (#481)
	112	+ */
	113	+ private static function failure_detail( int $code ): string {
	114	+ if ( ! self::is_firewall_block( $code ) ) {
	115	+ return sprintf( 'HTTP %d', $code );
	116	+ }
	117	+
	118	+ return sprintf(
	119	+ 'HTTP %d — your server\'s firewall is blocking the xSpeed cache warmer by user-agent, so this page was not warmed. Allow the user-agent "%s" (on xCloud this is the 8G firewall\'s bad-bot rule), or change it with the xspeed_preloader_user_agent filter.',
	120	+ $code,
	121	+ self::user_agent()
	122	+ );
	123	+ }
	124	+
	125	+ /** Option holding the last firewall-shaped warm refusal. */
	126	+ public const FIREWALL_BLOCK_OPTION = 'xspeed_preloader_firewall_block';
	127	+
	128	+ /**
	129	+ * Record that the origin refused a warm by user-agent, for ui_notices().
	130	+ *
	131	+ * An option rather than a transient: the condition is a server rule that
	132	+ * persists until someone changes it, and a notice that expired on its own
	133	+ * would let a site go back to never warming, silently. Cleared by
	134	+ * clear_firewall_block() on the first warm that succeeds. (#481)
	135	+ */
	136	+ private static function remember_firewall_block( string $url, int $code ): void {
	137	+ if ( ! function_exists( 'update_option' ) ) {
	138	+ return;
	139	+ }
	140	+ update_option(
	141	+ self::FIREWALL_BLOCK_OPTION,
	142	+ array(
	143	+ 'url' => $url,
	144	+ 'code' => $code,
	145	+ 'user_agent' => self::user_agent(),
	146	+ 'ts' => time(),
	147	+ ),
	148	+ false
	149	+ );
	150	+ }
	151	+
	152	+ /** Forget the firewall block once a warm gets through. */
	153	+ public static function clear_firewall_block(): void {
	154	+ if ( function_exists( 'delete_option' ) && self::firewall_block() ) {
	155	+ delete_option( self::FIREWALL_BLOCK_OPTION );
	156	+ }
	157	+ }
	158	+
	159	+ /** The last firewall-shaped refusal, or null when there isn't one. */
	160	+ public static function firewall_block(): ?array {
	161	+ if ( ! function_exists( 'get_option' ) ) {
	162	+ return null;
	163	+ }
	164	+ $block = get_option( self::FIREWALL_BLOCK_OPTION, null );
	165	+
	166	+ return ( is_array( $block ) && ! empty( $block['code'] ) ) ? $block : null;
	167	+ }
	168	+
	169	+ /**
61	170	* How many new remote images one warmed page may resolve.
62	171	*/
63	172	private static function remote_dimension_limit(): int {
64	173	/**
		@@ -280,9 +389,9 @@
280	389	$url,
281	390	array(
282	391	'timeout' => self::REQUEST_TIMEOUT,
283	392	'sslverify' => false,
284		- 'user-agent' => self::USER_AGENT,
	393	+ 'user-agent' => self::user_agent(),
285	394	'blocking' => true,
286	395	)
287	396	);
288	397	if ( is_wp_error( $response ) ) {
		@@ -296,13 +405,19 @@
296	405	$code = (int) wp_remote_retrieve_response_code( $response );
297	406	if ( $code >= 400 ) {
298	407	Activity_Log::record(
299	408	'preloader_warm_failed',
300		- sprintf( 'Warm %s failed (%s): HTTP %d', $cause, $url, $code ),
	409	+ sprintf( 'Warm %s failed (%s): %s', $cause, $url, self::failure_detail( $code ) ),
301	410	Activity_Log::WARN
302	411	);
	412	+ if ( self::is_firewall_block( $code ) ) {
	413	+ self::remember_firewall_block( $url, $code );
	414	+ }
303	415	return false;
304	416	}
	417	+ // A warm that got through proves the firewall is no longer refusing us,
	418	+ // so the notice must go — otherwise it outlives the problem. (#481)
	419	+ self::clear_firewall_block();
305	420	Activity_Log::record(
306	421	'preloader_warmed_one',
307	422	sprintf( 'Warmed %s (%s)', $url, $cause ),
308	423	Activity_Log::INFO
		@@ -315,9 +430,9 @@
315	430	$url,
316	431	array(
317	432	'timeout' => self::REQUEST_TIMEOUT,
318	433	'sslverify' => false,
319		- 'user-agent' => self::USER_AGENT,
	434	+ 'user-agent' => self::user_agent(),
320	435	'headers' => array(
321	436	'Accept' => 'text/html,application/xhtml+xml',
322	437	),
323	438	'blocking' => true,
		@@ -337,15 +452,19 @@
337	452	$code = (int) wp_remote_retrieve_response_code( $response );
338	453	if ( $code >= 400 ) {
339	454	$state['errors'][] = array(
340	455	'url' => $url,
341		- 'error' => sprintf( 'HTTP %d', $code ),
	456	+ 'error' => self::failure_detail( $code ),
342	457	'ts' => time(),
343	458	);
344	459	$state['errors'] = array_slice( $state['errors'], -20 );
	460	+ if ( self::is_firewall_block( $code ) ) {
	461	+ self::remember_firewall_block( $url, $code );
	462	+ }
345	463	return;
346	464	}
347	465
	466	+ self::clear_firewall_block();
348	467	self::warm_remote_dimensions( (string) wp_remote_retrieve_body( $response ) );
349	468	}
350	469
351	470	/**
		@@ -606,9 +725,9 @@
606	725	$sitemap_url,
607	726	array(
608	727	'timeout' => self::REQUEST_TIMEOUT,
609	728	'sslverify' => false,
610		- 'user-agent' => self::USER_AGENT,
	729	+ 'user-agent' => self::user_agent(),
611	730	)
612	731	);
613	732	if ( is_wp_error( $res ) ) {
614	733	// Record WHY, don't just vanish. "Unreachable" and "valid but