| 1 |
<?php |
| 2 |
/** |
| 3 |
* WCPOS Cloud Print relay integration. |
| 4 |
* |
| 5 |
* @package WCPOS\WooCommercePOS\Services |
| 6 |
*/ |
| 7 |
|
| 8 |
namespace WCPOS\WooCommercePOS\Services; |
| 9 |
|
| 10 |
use WP_Error; |
| 11 |
|
| 12 |
/** |
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* Talks to the WCPOS Cloud Print relay: registration/consent, job-pending |
| 14 |
* hints, and printer status queries. All relay knowledge lives here; the |
| 15 |
* REST controller only wraps these methods in responses. |
| 16 |
*/ |
| 17 |
class Cloud_Print_Relay_Service { |
| 18 |
const RELAY_URL = 'https://cloudprint.wcpos.com'; |
| 19 |
|
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/** |
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* Server-owned relay state {enabled, site_key, hint_secret, registered_at}. |
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* Deliberately a separate option from the client-writable cloud-print |
| 23 |
* settings so no settings write path can clobber or leak it. |
| 24 |
*/ |
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const OPTION = 'woocommerce_pos_cloud_print_relay'; |
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|
| 27 |
const VERIFY_TRANSIENT = 'wcpos_relay_verify_token'; |
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const STATUS_CACHE_TTL = 30; |
| 29 |
const STATUS_TRANSIENT_PREFIX = 'wcpos_relay_status_'; |
| 30 |
|
| 31 |
/** |
| 32 |
* Site-wide "relay unreachable" marker: one failed status call stops |
| 33 |
* further calls for the cache window, so a hanging relay costs one |
| 34 |
* timeout per window instead of one per printer per admin tab. |
| 35 |
*/ |
| 36 |
const DOWN_TRANSIENT = 'wcpos_relay_down'; |
| 37 |
|
| 38 |
const REREGISTER_GUARD = 3600; |
| 39 |
const REREGISTER_TRANSIENT = 'wcpos_relay_reregister_guard'; |
| 40 |
const REREGISTER_HOOK = 'wcpos_relay_reregister'; |
| 41 |
|
| 42 |
/** |
| 43 |
* Register relay event handlers. |
| 44 |
*/ |
| 45 |
public function __construct() { |
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add_action( 'woocommerce_pos_print_job_created', array( $this, 'send_hint' ), 10, 2 ); |
| 47 |
add_action( self::REREGISTER_HOOK, array( $this, 'reregister' ) ); |
| 48 |
} |
| 49 |
|
| 50 |
/** |
| 51 |
* Return the pending verification token, if a registration is in flight. |
| 52 |
* |
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* @return string|null |
| 54 |
*/ |
| 55 |
public static function pending_verification_token(): ?string { |
| 56 |
$token = get_transient( self::VERIFY_TRANSIENT ); |
| 57 |
if ( false === $token ) { |
| 58 |
return null; |
| 59 |
} |
| 60 |
// Single-use: consumed on first read, so a second reader (or a racing |
| 61 |
// registration attempt for this site) cannot replay the proof. |
| 62 |
delete_transient( self::VERIFY_TRANSIENT ); |
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|
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return (string) $token; |
| 65 |
} |
| 66 |
|
| 67 |
/** |
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* Register this site with the relay and persist its credentials. |
| 69 |
* |
| 70 |
* The relay fetches the verification token from this site while the |
| 71 |
* outbound request below is still open, proving consent and that WCPOS |
| 72 |
* is actually installed at the claimed URL. |
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* |
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* @param bool $admin_initiated True for an explicit admin action; false for |
| 75 |
* background re-registration, which must never |
| 76 |
* flip a relay the admin has since disabled. |
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* |
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* @return array|WP_Error Public relay fields or an error. |
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*/ |
| 80 |
public static function register_site( bool $admin_initiated = true ) { |
| 81 |
if ( ! self::is_enabled() ) { |
| 82 |
return new WP_Error( |
| 83 |
'wcpos_relay_disabled', |
| 84 |
__( 'WCPOS Cloud Print is disabled on this site.', 'woocommerce-pos' ), |
| 85 |
array( 'status' => 403 ) |
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); |
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} |
| 88 |
try { |
| 89 |
$token = bin2hex( random_bytes( 24 ) ); |
| 90 |
} catch ( \Exception $exception ) { |
| 91 |
return self::registration_error( __( 'Could not create a relay verification token.', 'woocommerce-pos' ) ); |
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} |
| 93 |
set_transient( self::VERIFY_TRANSIENT, $token, 5 * MINUTE_IN_SECONDS ); |
| 94 |
$response = wp_remote_post( |
| 95 |
self::relay_url() . '/api/register', |
| 96 |
array( |
| 97 |
'timeout' => 15, |
| 98 |
'headers' => array( 'Content-Type' => 'application/json' ), |
| 99 |
'body' => wp_json_encode( |
| 100 |
array( |
| 101 |
'site_url' => home_url(), |
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'verify_token' => $token, |
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) |
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), |
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) |
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); |
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delete_transient( self::VERIFY_TRANSIENT ); |
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|
| 109 |
if ( is_wp_error( $response ) ) { |
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return self::registration_error( $response->get_error_message() ); |
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} |
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|
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$data = json_decode( wp_remote_retrieve_body( $response ), true ); |
| 114 |
if ( 201 !== wp_remote_retrieve_response_code( $response ) ) { |
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$message = \is_array( $data ) ? (string) ( $data['message'] ?? $data['error'] ?? '' ) : ''; |
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|
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return self::registration_error( '' !== $message ? sanitize_text_field( $message ) : __( 'Relay registration failed.', 'woocommerce-pos' ) ); |
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} |
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|
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$data = \is_array( $data ) ? $data : array(); |
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$site_key = sanitize_text_field( (string) ( $data['site_key'] ?? '' ) ); |
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$hint_secret = sanitize_text_field( (string) ( $data['hint_secret'] ?? '' ) ); |
| 123 |
if ( 1 !== preg_match( '/^[a-f0-9]{32}$/i', $site_key ) || 1 !== preg_match( '/^[a-f0-9]{64}$/i', $hint_secret ) ) { |
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return self::registration_error( __( 'Relay registration returned invalid credentials.', 'woocommerce-pos' ) ); |
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} |
| 126 |
|
| 127 |
// Re-read at completion time: a background re-registration must adopt |
| 128 |
// the admin's latest enabled/disabled intent, not the state at launch. |
| 129 |
$current = self::settings(); |
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update_option( |
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self::OPTION, |
| 132 |
array( |
| 133 |
'enabled' => $admin_initiated ? true : ! empty( $current['enabled'] ), |
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'site_key' => strtolower( $site_key ), |
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'hint_secret' => strtolower( $hint_secret ), |
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'registered_at' => time(), |
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) |
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); |
| 139 |
delete_transient( self::DOWN_TRANSIENT ); |
| 140 |
// status() consults the per-printer negative cache before DOWN_TRANSIENT, |
| 141 |
// so clearing the site-wide marker alone is not enough: a printer that hit |
| 142 |
// an "unknown site" 404 backed off for REREGISTER_GUARD, and without this |
| 143 |
// it would keep returning null for the full hour even though the site_key |
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// is valid again. Dropping those entries lets status resume on the next call. |
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self::clear_status_cache(); |
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|
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// The printer URL is always rebuilt from the validated site_key — |
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// never from the relay response — so a compromised relay cannot |
| 149 |
// point printers (and their tokens) at another host. |
| 150 |
return array( |
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'enabled' => true, |
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'printer_base_url' => self::printer_base_url( strtolower( $site_key ) ), |
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); |
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} |
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|
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/** |
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* Disable relay use while retaining the deterministic site credentials. |
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* |
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* @deprecated The stored flag is no longer consulted; opt out with the |
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* `woocommerce_pos_cloud_print_relay_enabled` filter. |
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* |
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* @return array Public relay state. |
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*/ |
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public static function disable(): array { |
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$stored = self::settings(); |
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$stored['enabled'] = false; |
| 167 |
update_option( self::OPTION, $stored ); |
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|
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return array( 'enabled' => false ); |
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} |
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|
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/** |
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* Whether the relay service may be used at all. |
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* |
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* The relay is on by default — there is no admin toggle. Sites that |
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* really want to opt out do so in code: |
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* |
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* add_filter( 'woocommerce_pos_cloud_print_relay_enabled', '__return_false' ); |
| 179 |
*/ |
| 180 |
public static function is_enabled(): bool { |
| 181 |
return (bool) apply_filters( 'woocommerce_pos_cloud_print_relay_enabled', true ); |
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} |
| 183 |
|
| 184 |
/** |
| 185 |
* Public relay state for REST responses: never includes the secret. |
| 186 |
* |
| 187 |
* `enabled` means registered and usable; `available` tells the settings |
| 188 |
* app whether it should self-register (false only when the opt-out |
| 189 |
* filter is in place). The stored `enabled` flag is deliberately not |
| 190 |
* consulted — the filter is the only off switch. |
| 191 |
* |
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* @return array |
| 193 |
*/ |
| 194 |
public static function public_state(): array { |
| 195 |
if ( ! self::is_enabled() ) { |
| 196 |
return array( |
| 197 |
'enabled' => false, |
| 198 |
'available' => false, |
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); |
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} |
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|
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$relay = self::settings(); |
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$state = array( |
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'enabled' => false, |
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'available' => true, |
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); |
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// Case-insensitive to match valid_credentials(): registration lowercases |
| 208 |
// on write, but a legacy uppercase key still signs hints and status |
| 209 |
// calls fine, so it must not report itself disabled to the settings app. |
| 210 |
if ( 1 === preg_match( '/^[a-f0-9]{32}$/i', (string) ( $relay['site_key'] ?? '' ) ) ) { |
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$state['enabled'] = true; |
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$state['printer_base_url'] = self::printer_base_url( (string) $relay['site_key'] ); |
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} |
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|
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return $state; |
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} |
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|
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/** |
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* Send a best-effort hint when a polling printer gets a job. |
| 220 |
* |
| 221 |
* @param int $job_id Print job ID. |
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* @param string $printer_id Printer ID. |
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*/ |
| 224 |
public function send_hint( $job_id, $printer_id ): void { |
| 225 |
$relay = self::settings(); |
| 226 |
if ( ! self::is_enabled() || ! self::valid_credentials( $relay ) ) { |
| 227 |
return; |
| 228 |
} |
| 229 |
|
| 230 |
$printer = ( new Cloud_Print_Registry() )->get_printer( sanitize_text_field( (string) $printer_id ) ); |
| 231 |
if ( null === $printer || ! Provider::is_polling( (string) ( $printer['provider'] ?? '' ) ) ) { |
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return; |
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} |
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|
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$site_key = (string) $relay['site_key']; |
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$path = '/api/hint/' . $site_key; |
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$timestamp = (string) time(); |
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$body = wp_json_encode( array( 'printer_id' => (string) $printer_id ) ); |
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|
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// Best-effort by design: a lost hint costs at most one heartbeat |
| 241 |
// interval of print latency, so failures are deliberately silent. |
| 242 |
wp_remote_post( |
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self::relay_url() . $path, |
| 244 |
array( |
| 245 |
'blocking' => false, |
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'timeout' => 2, |
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'headers' => self::signed_headers( 'POST', $path, $timestamp, $body, (string) $relay['hint_secret'] ), |
| 248 |
'body' => $body, |
| 249 |
) |
| 250 |
); |
| 251 |
} |
| 252 |
|
| 253 |
/** |
| 254 |
* Query the cached relay status for a printer. |
| 255 |
* |
| 256 |
* @param string $printer_id Printer ID. |
| 257 |
* |
| 258 |
* @return array|null Relay status or null on failure/when disabled. |
| 259 |
*/ |
| 260 |
public static function status( string $printer_id ): ?array { |
| 261 |
$relay = self::settings(); |
| 262 |
if ( ! self::is_enabled() || ! self::valid_credentials( $relay ) ) { |
| 263 |
return null; |
| 264 |
} |
| 265 |
|
| 266 |
$key = self::STATUS_TRANSIENT_PREFIX . $printer_id; |
| 267 |
$cached = get_transient( $key ); |
| 268 |
if ( false !== $cached ) { |
| 269 |
return ! empty( $cached['failed'] ) ? null : $cached; |
| 270 |
} |
| 271 |
if ( false !== get_transient( self::DOWN_TRANSIENT ) ) { |
| 272 |
return null; |
| 273 |
} |
| 274 |
|
| 275 |
$site_key = (string) $relay['site_key']; |
| 276 |
$path = '/api/status/' . $site_key; |
| 277 |
$timestamp = (string) time(); |
| 278 |
$response = wp_remote_get( |
| 279 |
self::relay_url() . $path . '?printer_id=' . rawurlencode( $printer_id ), |
| 280 |
array( |
| 281 |
'timeout' => 3, |
| 282 |
'headers' => self::signed_headers( 'GET', $path, $timestamp, $printer_id, (string) $relay['hint_secret'] ), |
| 283 |
) |
| 284 |
); |
| 285 |
|
| 286 |
if ( is_wp_error( $response ) ) { |
| 287 |
self::note_status_failure( $key ); |
| 288 |
|
| 289 |
return null; |
| 290 |
} |
| 291 |
|
| 292 |
$code = wp_remote_retrieve_response_code( $response ); |
| 293 |
$data = json_decode( wp_remote_retrieve_body( $response ), true ); |
| 294 |
// Exact match on the relay's machine-readable error field; the |
| 295 |
// registry was rebuilt, so a guarded re-registration restores the |
| 296 |
// same deterministic site key. |
| 297 |
if ( 404 === $code && \is_array( $data ) && 'unknown site' === ( $data['error'] ?? '' ) ) { |
| 298 |
self::schedule_reregistration(); |
| 299 |
|
| 300 |
// Back off for the re-registration window, not the cache window. |
| 301 |
// This 404 is not a transient relay hiccup: the stored site_key is |
| 302 |
// not in the relay's registry, and nothing about that changes until |
| 303 |
// a re-registration succeeds — which is itself rate-limited to once |
| 304 |
// per REREGISTER_GUARD. Falling through to the 30s failure window |
| 305 |
// would replay the identical 404 twice a minute forever whenever a |
| 306 |
// site cannot re-register (the relay cannot reach its verification |
| 307 |
// endpoint, say), which is exactly what one site was doing: ~2,000 |
| 308 |
// pointless requests a day. A successful registration deletes |
| 309 |
// DOWN_TRANSIENT, so this self-heals the moment re-registration |
| 310 |
// works rather than pinning the site down for the full hour. |
| 311 |
self::note_status_failure( $key, self::REREGISTER_GUARD ); |
| 312 |
|
| 313 |
return null; |
| 314 |
} |
| 315 |
if ( 200 !== $code || ! \is_array( $data ) ) { |
| 316 |
self::note_status_failure( $key ); |
| 317 |
|
| 318 |
return null; |
| 319 |
} |
| 320 |
|
| 321 |
$status = array( |
| 322 |
'origin_status' => sanitize_text_field( (string) ( $data['origin_status'] ?? '' ) ), |
| 323 |
'origin_block_signal' => sanitize_text_field( (string) ( $data['origin_block_signal'] ?? '' ) ), |
| 324 |
'last_seen_seconds_ago' => isset( $data['last_seen_seconds_ago'] ) ? max( 0, (int) $data['last_seen_seconds_ago'] ) : null, |
| 325 |
); |
| 326 |
set_transient( $key, $status, self::STATUS_CACHE_TTL ); |
| 327 |
|
| 328 |
return $status; |
| 329 |
} |
| 330 |
|
| 331 |
/** |
| 332 |
* The relay's block signal for a printer, when it reports one. |
| 333 |
* |
| 334 |
* Reads the same transient cache as status(), so calling both costs one |
| 335 |
* relay round-trip at most. |
| 336 |
* |
| 337 |
* @param string $printer_id Printer ID. |
| 338 |
* |
| 339 |
* @return string|null |
| 340 |
*/ |
| 341 |
public static function status_detail( string $printer_id ): ?string { |
| 342 |
$status = self::status( $printer_id ); |
| 343 |
if ( null !== $status && 'blocked' === $status['origin_status'] && '' !== $status['origin_block_signal'] ) { |
| 344 |
return $status['origin_block_signal']; |
| 345 |
} |
| 346 |
|
| 347 |
return null; |
| 348 |
} |
| 349 |
|
| 350 |
/** |
| 351 |
* Build a relay-compatible HMAC signature. |
| 352 |
* |
| 353 |
* @param string $method HTTP method. |
| 354 |
* @param string $path Request path without query string. |
| 355 |
* @param string $timestamp Unix timestamp. |
| 356 |
* @param string $payload Signed payload. |
| 357 |
* @param string $secret Hex-encoded signing secret. |
| 358 |
* |
| 359 |
* @return string Lowercase hexadecimal signature. |
| 360 |
*/ |
| 361 |
public static function sign( string $method, string $path, string $timestamp, string $payload, string $secret ): string { |
| 362 |
$key = hex2bin( $secret ); |
| 363 |
|
| 364 |
return false === $key ? '' : hash_hmac( 'sha256', $method . "\n" . $path . "\n" . $timestamp . "\n" . $payload, $key ); |
| 365 |
} |
| 366 |
|
| 367 |
/** |
| 368 |
* Build the public printer URL for a registered site. |
| 369 |
* |
| 370 |
* @param string $site_key Relay site key. |
| 371 |
*/ |
| 372 |
public static function printer_base_url( string $site_key ): string { |
| 373 |
return self::relay_url() . '/p/' . rawurlencode( $site_key ); |
| 374 |
} |
| 375 |
|
| 376 |
/** |
| 377 |
* Re-register after the relay reports an unknown site. |
| 378 |
* |
| 379 |
* Bails only when the code-level opt-out filter is in place — a pending |
| 380 |
* cron event must never register a site that opted out. |
| 381 |
*/ |
| 382 |
public function reregister(): void { |
| 383 |
if ( ! self::is_enabled() ) { |
| 384 |
return; |
| 385 |
} |
| 386 |
self::register_site( false ); |
| 387 |
} |
| 388 |
|
| 389 |
/** |
| 390 |
* Return stored relay settings. |
| 391 |
* |
| 392 |
* @return array |
| 393 |
*/ |
| 394 |
private static function settings(): array { |
| 395 |
$stored = get_option( self::OPTION, array() ); |
| 396 |
|
| 397 |
return \is_array( $stored ) ? $stored : array(); |
| 398 |
} |
| 399 |
|
| 400 |
/** |
| 401 |
* Check stored relay credentials before using them for signing. |
| 402 |
* |
| 403 |
* @param array $relay Relay settings. |
| 404 |
*/ |
| 405 |
private static function valid_credentials( array $relay ): bool { |
| 406 |
return 1 === preg_match( '/^[a-f0-9]{32}$/i', (string) ( $relay['site_key'] ?? '' ) ) |
| 407 |
&& 1 === preg_match( '/^[a-f0-9]{64}$/i', (string) ( $relay['hint_secret'] ?? '' ) ); |
| 408 |
} |
| 409 |
|
| 410 |
/** |
| 411 |
* Build signed relay request headers. |
| 412 |
* |
| 413 |
* @param string $method HTTP method. |
| 414 |
* @param string $path Request path. |
| 415 |
* @param string $timestamp Unix timestamp. |
| 416 |
* @param string $payload Signed payload. |
| 417 |
* @param string $secret Hex-encoded signing secret. |
| 418 |
* |
| 419 |
* @return array |
| 420 |
*/ |
| 421 |
private static function signed_headers( string $method, string $path, string $timestamp, string $payload, string $secret ): array { |
| 422 |
return array( |
| 423 |
'X-Relay-Timestamp' => $timestamp, |
| 424 |
'X-Relay-Signature' => self::sign( $method, $path, $timestamp, $payload, $secret ), |
| 425 |
'Content-Type' => 'application/json', |
| 426 |
); |
| 427 |
} |
| 428 |
|
| 429 |
/** |
| 430 |
* Record a failed status call: per-printer negative cache plus the |
| 431 |
* site-wide down marker so other printers skip their calls entirely. |
| 432 |
* |
| 433 |
* @param string $transient_key Per-printer status transient key. |
| 434 |
* @param int|null $ttl Backoff seconds; defaults to STATUS_CACHE_TTL. |
| 435 |
* Callers pass a longer window when the |
| 436 |
* failure cannot clear on its own within it. |
| 437 |
*/ |
| 438 |
private static function note_status_failure( string $transient_key, ?int $ttl = null ): void { |
| 439 |
$ttl = null === $ttl ? self::STATUS_CACHE_TTL : max( 1, $ttl ); |
| 440 |
set_transient( $transient_key, array( 'failed' => true ), $ttl ); |
| 441 |
set_transient( self::DOWN_TRANSIENT, true, $ttl ); |
| 442 |
} |
| 443 |
|
| 444 |
/** |
| 445 |
* Drop every per-printer status cache. |
| 446 |
* |
| 447 |
* Because status() checks the per-printer negative cache before DOWN_TRANSIENT, |
| 448 |
* a successful (re-)registration must clear these entries too — otherwise a |
| 449 |
* printer that backed off on an "unknown site" 404 keeps returning null for |
| 450 |
* the full REREGISTER_GUARD window despite the site_key being valid again. |
| 451 |
* Dropping any live positive caches is harmless: the next call re-polls. |
| 452 |
*/ |
| 453 |
private static function clear_status_cache(): void { |
| 454 |
foreach ( ( new Cloud_Print_Registry() )->get_printers() as $printer ) { |
| 455 |
$printer_id = (string) ( $printer['id'] ?? '' ); |
| 456 |
if ( '' !== $printer_id ) { |
| 457 |
delete_transient( self::STATUS_TRANSIENT_PREFIX . $printer_id ); |
| 458 |
} |
| 459 |
} |
| 460 |
} |
| 461 |
|
| 462 |
/** |
| 463 |
* Schedule one guarded background re-registration. |
| 464 |
*/ |
| 465 |
private static function schedule_reregistration(): void { |
| 466 |
if ( false !== get_transient( self::REREGISTER_TRANSIENT ) ) { |
| 467 |
return; |
| 468 |
} |
| 469 |
set_transient( self::REREGISTER_TRANSIENT, true, self::REREGISTER_GUARD ); |
| 470 |
wp_schedule_single_event( time(), self::REREGISTER_HOOK ); |
| 471 |
} |
| 472 |
|
| 473 |
/** |
| 474 |
* Build a consistent registration error. |
| 475 |
* |
| 476 |
* @param string $message Error message. |
| 477 |
* |
| 478 |
* @return WP_Error |
| 479 |
*/ |
| 480 |
private static function registration_error( string $message ): WP_Error { |
| 481 |
return new WP_Error( 'wcpos_relay_registration_failed', $message, array( 'status' => 502 ) ); |
| 482 |
} |
| 483 |
|
| 484 |
/** |
| 485 |
* Return the filterable relay base URL. |
| 486 |
*/ |
| 487 |
private static function relay_url(): string { |
| 488 |
return untrailingslashit( esc_url_raw( (string) apply_filters( 'woocommerce_pos_cloud_print_relay_url', self::RELAY_URL ) ) ); |
| 489 |
} |
| 490 |
} |
| 491 |
|
