<?php
/**
* CDN handling for LiteSpeed Cache.
*
* Rewrites eligible asset URLs to configured CDN endpoints and integrates with WordPress filters.
*
* @since 1.2.3
* @package LiteSpeed
*/
namespace LiteSpeed;
defined( 'WPINC' ) || exit();
/**
* Class CDN
*
* Processes page content and WordPress asset URLs to map to CDN domains according to settings.
*/
class CDN extends Root {
const LOG_TAG = '[CDN]';
const BYPASS = 'LITESPEED_BYPASS_CDN';
/**
* The working HTML/content buffer being processed.
*
* @var string
*/
private $content;
/**
* Whether CDN feature is enabled.
*
* @var bool
*/
private $_cfg_cdn;
/**
* List of original site URLs (may include wildcards) to be replaced.
*
* @var string[]
*/
private $_cfg_url_ori;
/**
* List of directories considered internal/original for CDN rewriting.
*
* @var string[]
*/
private $_cfg_ori_dir;
/**
* CDN mapping rules; keys include mapping kinds or file extensions, values are URL(s).
*
* @var array<string,string|string[]>
*/
private $_cfg_cdn_mapping = [];
/**
* List of URL substrings/regex used to exclude items from CDN.
*
* @var string[]
*/
private $_cfg_cdn_exclude;
/**
* Hosts used by CDN mappings for quick membership checks.
*
* @var string[]
*/
private $cdn_mapping_hosts = [];
/**
* Auto-managed CDN filetype map keyed by mapping toggle.
*
* Single source of truth for the filetypes implicitly handled by the
* Include Images / Include CSS / Include JS toggles. Used by both
* CDN::init() (auto-injection) and Admin_Settings::save() (auto-stripping)
* so that the two sides stay in sync.
*
* @since 7.9
* @access public
* @return array<string,string[]>
*/
public static function auto_managed_filetypes() {
return apply_filters(
'litespeed_cdn_auto_managed_filetypes',
[
Base::CDN_MAPPING_INC_IMG => [ '.jpg', '.jpeg', '.png', '.gif', '.svg', '.webp', '.avif' ],
Base::CDN_MAPPING_INC_CSS => [ '.css' ],
Base::CDN_MAPPING_INC_JS => [ '.js' ],
]
);
}
/**
* Initialize CDN integration and register filters if enabled.
*
* @since 1.2.3
* @return void
*/
public function init() {
self::debug2( 'init' );
if ( defined( self::BYPASS ) ) {
self::debug2( 'CDN bypass' );
return;
}
if ( ! Router::can_cdn() ) {
if ( ! defined( self::BYPASS ) ) {
define( self::BYPASS, true );
}
return;
}
$this->_cfg_cdn = $this->conf( Base::O_CDN );
if ( ! $this->_cfg_cdn ) {
if ( ! defined( self::BYPASS ) ) {
define( self::BYPASS, true );
}
return;
}
$this->_cfg_url_ori = $this->conf( Base::O_CDN_ORI );
// Parse cdn mapping data to array( 'filetype' => 'url' )
$mapping_to_check = [ Base::CDN_MAPPING_INC_IMG, Base::CDN_MAPPING_INC_CSS, Base::CDN_MAPPING_INC_JS ];
$auto_managed = self::auto_managed_filetypes();
foreach ( $this->conf( Base::O_CDN_MAPPING ) as $v ) {
if ( ! $v[ Base::CDN_MAPPING_URL ] ) {
continue;
}
$this_url = $v[ Base::CDN_MAPPING_URL ];
$this_host = wp_parse_url( $this_url, PHP_URL_HOST );
// Check img/css/js
foreach ( $mapping_to_check as $to_check ) {
if ( $v[ $to_check ] ) {
self::debug2( 'mapping ' . $to_check . ' -> ' . $this_url );
// If filetype to url is one to many, make url be an array
$this->_append_cdn_mapping( $to_check, $this_url );
// Auto-inject extensions managed by this toggle via _append_cdn_mapping() to preserve multi-CDN one-to-many semantics.
if ( ! empty( $auto_managed[ $to_check ] ) ) {
foreach ( $auto_managed[ $to_check ] as $ext ) {
$this->_append_cdn_mapping( $ext, $this_url );
}
// Set the FILETYPE sentinel so _replace_file_types() runs even with an empty manual textarea, otherwise CSS/JS replacement is silently broken.
$this->_cfg_cdn_mapping[ Base::CDN_MAPPING_FILETYPE ] = true;
}
if ( ! in_array( $this_host, $this->cdn_mapping_hosts, true ) ) {
$this->cdn_mapping_hosts[] = $this_host;
}
}
}
// Check file types
if ( $v[ Base::CDN_MAPPING_FILETYPE ] ) {
foreach ( $v[ Base::CDN_MAPPING_FILETYPE ] as $v2 ) {
$this->_cfg_cdn_mapping[ Base::CDN_MAPPING_FILETYPE ] = true;
// If filetype to url is one to many, make url be an array
$this->_append_cdn_mapping( $v2, $this_url );
if ( ! in_array( $this_host, $this->cdn_mapping_hosts, true ) ) {
$this->cdn_mapping_hosts[] = $this_host;
}
}
self::debug2( 'mapping ' . implode( ',', $v[ Base::CDN_MAPPING_FILETYPE ] ) . ' -> ' . $this_url );
}
}
if ( ! $this->_cfg_url_ori || ! $this->_cfg_cdn_mapping ) {
if ( ! defined( self::BYPASS ) ) {
define( self::BYPASS, true );
}
return;
}
$this->_cfg_ori_dir = $this->conf( Base::O_CDN_ORI_DIR );
// In case user customized upload path
if ( defined( 'UPLOADS' ) ) {
$this->_cfg_ori_dir[] = UPLOADS;
}
// Check if need preg_replace
$this->_cfg_url_ori = Utility::wildcard2regex( $this->_cfg_url_ori );
$this->_cfg_cdn_exclude = $this->conf( Base::O_CDN_EXC );
if ( ! empty( $this->_cfg_cdn_mapping[ Base::CDN_MAPPING_INC_IMG ] ) ) {
// Hook to srcset
if ( function_exists( 'wp_calculate_image_srcset' ) ) {
add_filter( 'wp_calculate_image_srcset', [ $this, 'srcset' ], 999 );
}
// Hook to mime icon
add_filter( 'wp_get_attachment_image_src', [ $this, 'attach_img_src' ], 999 );
add_filter( 'wp_get_attachment_url', [ $this, 'url_img' ], 999 );
}
if ( ! empty( $this->_cfg_cdn_mapping[ Base::CDN_MAPPING_INC_CSS ] ) ) {
add_filter( 'style_loader_src', [ $this, 'url_css' ], 999 );
}
if ( ! empty( $this->_cfg_cdn_mapping[ Base::CDN_MAPPING_INC_JS ] ) ) {
add_filter( 'script_loader_src', [ $this, 'url_js' ], 999 );
}
add_filter( 'litespeed_buffer_finalize', [ $this, 'finalize' ], 30 );
}
/**
* Associate all filetypes with CDN URL.
*
* @since 2.0
* @access private
*
* @param string $filetype Mapping key (e.g., extension or mapping constant).
* @param string $url CDN base URL to use for this mapping.
* @return void
*/
private function _append_cdn_mapping( $filetype, $url ) {
// If filetype to url is one to many, make url be an array
if ( empty( $this->_cfg_cdn_mapping[ $filetype ] ) ) {
$this->_cfg_cdn_mapping[ $filetype ] = $url;
} elseif ( is_array( $this->_cfg_cdn_mapping[ $filetype ] ) ) {
// Append url to filetype
$this->_cfg_cdn_mapping[ $filetype ][] = $url;
} else {
// Convert _cfg_cdn_mapping from string to array
$this->_cfg_cdn_mapping[ $filetype ] = [ $this->_cfg_cdn_mapping[ $filetype ], $url ];
}
}
/**
* Whether the given type is included in CDN mappings.
*
* @since 1.6.2.1
*
* @param string $type 'css' or 'js'.
* @return bool True if included in CDN.
*/
public function inc_type( $type ) {
if ( 'css' === $type && ! empty( $this->_cfg_cdn_mapping[ Base::CDN_MAPPING_INC_CSS ] ) ) {
return true;
}
if ( 'js' === $type && ! empty( $this->_cfg_cdn_mapping[ Base::CDN_MAPPING_INC_JS ] ) ) {
return true;
}
return false;
}
/**
* Run CDN processing on finalized buffer.
* NOTE: After cache finalized, cannot change cache control.
*
* @since 1.2.3
* @access public
*
* @param string $content The HTML/content buffer.
* @return string The processed content.
*/
public function finalize( $content ) {
// Bypass REST JSON: HTML rewrites would break its escaping. Must check here, not init() — REST_REQUEST is undefined there.
if ( $this->cls( 'REST' )->is_rest() ) {
self::debug( 'bypassed: REST response' );
return $content;
}
$this->content = $content;
$this->_finalize();
return $this->content;
}
/**
* Replace eligible URLs with CDN URLs in the working buffer.
*
* @since 1.2.3
* @access private
* @return void
*/
private function _finalize() {
if ( defined( self::BYPASS ) ) {
return;
}
self::debug( 'CDN _finalize' );
// Start replacing img src
if ( ! empty( $this->_cfg_cdn_mapping[ Base::CDN_MAPPING_INC_IMG ] ) ) {
$this->_replace_img();
$this->_replace_inline_css();
}
if ( ! empty( $this->_cfg_cdn_mapping[ Base::CDN_MAPPING_FILETYPE ] ) ) {
$this->_replace_file_types();
}
}
/**
* Parse all file types and replace according to configured attributes.
*
* @since 1.2.3
* @access private
* @return void
*/
private function _replace_file_types() {
$ele_to_check = $this->conf( Base::O_CDN_ATTR );
foreach ( $ele_to_check as $v ) {
if ( ! $v || false === strpos( $v, '.' ) ) {
self::debug2( 'replace setting bypassed: no . attribute ' . $v );
continue;
}
self::debug2( 'replace attribute ' . $v );
$v = explode( '.', $v );
$attr = preg_quote( $v[1], '#' );
if ( $v[0] ) {
$pattern = '#<' . preg_quote( $v[0], '#' ) . '([^>]+)' . $attr . '=([\'"])(.+)\g{2}#iU';
} else {
$pattern = '# ' . $attr . '=([\'"])(.+)\g{1}#iU';
}
preg_match_all( $pattern, $this->content, $matches );
if (empty($matches[$v[0] ? 3 : 2])) {
continue;
}
foreach ($matches[$v[0] ? 3 : 2] as $k2 => $url) {
// self::debug2( 'check ' . $url );
$postfix = '.' . pathinfo((string) wp_parse_url($url, PHP_URL_PATH), PATHINFO_EXTENSION);
if (!array_key_exists($postfix, $this->_cfg_cdn_mapping)) {
// self::debug2( 'non-existed postfix ' . $postfix );
continue;
}
self::debug2( 'matched file_type ' . $postfix . ' : ' . $url );
$url2 = $this->rewrite( $url, Base::CDN_MAPPING_FILETYPE, $postfix );
if ( ! $url2 ) {
continue;
}
$attr_str = str_replace( $url, $url2, $matches[0][ $k2 ] );
$this->content = str_replace( $matches[0][ $k2 ], $attr_str, $this->content );
}
}
}
/**
* Parse all images and replace their src attributes.
*
* @since 1.2.3
* @access private
* @return void
*/
private function _replace_img() {
preg_match_all( '#<img([^>]+?)src=([\'"\\\]*)([^\'"\s\\\>]+)([\'"\\\]*)([^>]*)>#i', $this->content, $matches );
foreach ( $matches[3] as $k => $url ) {
// Backslash by the quote = escaped JSON/JS context; rewriting would corrupt the escaping.
if ( false !== strpos( $matches[2][ $k ], '\\' ) || false !== strpos( $matches[4][ $k ], '\\' ) ) {
continue;
}
// Check if is a DATA-URI
if ( false !== strpos( $url, 'data:image' ) ) {
continue;
}
$url2 = $this->rewrite( $url, Base::CDN_MAPPING_INC_IMG );
if ( ! $url2 ) {
continue;
}
$html_snippet = sprintf( '<img %1$s src=%2$s %3$s>', $matches[1][ $k ], $matches[2][ $k ] . $url2 . $matches[4][ $k ], $matches[5][ $k ] );
$this->content = str_replace( $matches[0][ $k ], $html_snippet, $this->content );
}
}
/**
* Parse and replace all inline styles containing url().
*
* @since 1.2.3
* @access private
* @return void
*/
private function _replace_inline_css() {
self::debug2( '_replace_inline_css', $this->_cfg_cdn_mapping );
/**
* Excludes `\` from URL matching
*
* @see #959152 - WordPress LSCache CDN Mapping causing malformed URLS
* @see #685485
* @since 3.0
*/
preg_match_all( '/url\((?![\'"]?data)[\'"]?(.+?)[\'"]?\)/i', $this->content, $matches );
foreach ( $matches[1] as $k => $url ) {
$url = str_replace( [ ' ', '\t', '\n', '\r', '\0', '\x0B', '"', "'", '"', ''' ], '', $url );
// Skip escaped JSON/JS contexts — same family as #959152.
if ( false !== strpos( $url, '\\' ) ) {
continue;
}
// Parse file postfix
$parsed_url = wp_parse_url( $url, PHP_URL_PATH );
if ( ! $parsed_url ) {
continue;
}
$postfix = '.' . pathinfo( $parsed_url, PATHINFO_EXTENSION );
if ( array_key_exists( $postfix, $this->_cfg_cdn_mapping ) ) {
self::debug2( 'matched file_type ' . $postfix . ' : ' . $url );
$url2 = $this->rewrite( $url, Base::CDN_MAPPING_FILETYPE, $postfix );
if ( ! $url2 ) {
continue;
}
} elseif ( in_array( $postfix, [ 'jpg', 'jpeg', 'png', 'gif', 'svg', 'webp', 'avif' ], true ) ) {
$url2 = $this->rewrite( $url, Base::CDN_MAPPING_INC_IMG );
if ( ! $url2 ) {
continue;
}
} else {
continue;
}
$attr = str_replace( $matches[1][ $k ], $url2, $matches[0][ $k ] );
$this->content = str_replace( $matches[0][ $k ], $attr, $this->content );
}
self::debug2( '_replace_inline_css done' );
}
/**
* Filter: wp_get_attachment_image_src.
*
* @since 1.2.3
* @since 1.7 Removed static from function.
* @access public
*
* @param array{0:string,1:int,2:int} $img The URL of the attachment image src, the width, the height.
* @return array{0:string,1:int,2:int}
*/
public function attach_img_src( $img ) {
if ( $img ) {
$url = $this->rewrite( $img[0], Base::CDN_MAPPING_INC_IMG );
if ( $url ) {
$img[0] = $url;
}
}
return $img;
}
/**
* Try to rewrite one image URL with CDN.
*
* @since 1.7
* @access public
*
* @param string $url Original URL.
* @return string URL after rewriting, or original if not applicable.
*/
public function url_img( $url ) {
if ( $url ) {
$url2 = $this->rewrite( $url, Base::CDN_MAPPING_INC_IMG );
if ( $url2 ) {
$url = $url2;
}
}
return $url;
}
/**
* Try to rewrite one CSS URL with CDN.
*
* @since 1.7
* @access public
*
* @param string $url Original URL.
* @return string URL after rewriting, or original if not applicable.
*/
public function url_css( $url ) {
if ( $url ) {
$url2 = $this->rewrite( $url, Base::CDN_MAPPING_INC_CSS );
if ( $url2 ) {
$url = $url2;
}
}
return $url;
}
/**
* Try to rewrite one JS URL with CDN.
*
* @since 1.7
* @access public
*
* @param string $url Original URL.
* @return string URL after rewriting, or original if not applicable.
*/
public function url_js( $url ) {
if ( $url ) {
$url2 = $this->rewrite( $url, Base::CDN_MAPPING_INC_JS );
if ( $url2 ) {
$url = $url2;
}
}
return $url;
}
/**
* Filter responsive image sources for CDN.
*
* @since 1.2.3
* @since 1.7 Removed static from function.
* @access public
*
* @param array<int,array{url:string}> $srcs Srcset array.
* @return array<int,array{url:string}>
*/
public function srcset( $srcs ) {
if ( $srcs ) {
foreach ( $srcs as $w => $data ) {
$url = $this->rewrite( $data['url'], Base::CDN_MAPPING_INC_IMG );
if ( ! $url ) {
continue;
}
$srcs[ $w ]['url'] = $url;
}
}
return $srcs;
}
/**
* Replace an URL with mapped CDN URL, if applicable.
*
* @since 1.2.3
* @access public
*
* @param string $url Target URL.
* @param string $mapping_kind Mapping kind (e.g., Base::CDN_MAPPING_INC_IMG or Base::CDN_MAPPING_FILETYPE).
* @param string|false $postfix File extension (with dot) when mapping by file type.
* @return string|false Replaced URL on success, false when not applicable.
*/
public function rewrite( $url, $mapping_kind, $postfix = false ) {
self::debug2( 'rewrite ' . $url );
$url_parsed = wp_parse_url( $url );
if ( empty( $url_parsed['path'] ) ) {
self::debug2( '-rewrite bypassed: no path' );
return false;
}
// Only images under wp-content/wp-includes can be replaced
$is_internal_folder = Utility::str_hit_array( $url_parsed['path'], $this->_cfg_ori_dir );
if ( ! $is_internal_folder ) {
self::debug2( '-rewrite failed: path not match: ' . LSCWP_CONTENT_FOLDER );
return false;
}
// Check if is external url
if ( ! empty( $url_parsed['host'] ) ) {
if ( ! Utility::internal( $url_parsed['host'] ) && ! $this->_is_ori_url( $url ) ) {
self::debug2( '-rewrite failed: host not internal' );
return false;
}
}
$exclude = Utility::str_hit_array( $url, $this->_cfg_cdn_exclude );
if ( $exclude ) {
self::debug2( '-abort excludes ' . $exclude );
return false;
}
// Fill full url before replacement
if ( empty( $url_parsed['host'] ) ) {
$url = Utility::uri2url( $url );
self::debug2( '-fill before rewritten: ' . $url );
$url_parsed = wp_parse_url( $url );
}
$scheme = ! empty( $url_parsed['scheme'] ) ? $url_parsed['scheme'] . ':' : '';
// Find the mapping url to be replaced to
if ( empty( $this->_cfg_cdn_mapping[ $mapping_kind ] ) ) {
return false;
}
if ( Base::CDN_MAPPING_FILETYPE !== $mapping_kind ) {
$final_url = $this->_cfg_cdn_mapping[ $mapping_kind ];
} else {
// select from file type
$final_url = $this->_cfg_cdn_mapping[ $postfix ];
if ( ! $final_url ) {
return false;
}
}
// If filetype to url is one to many, need to random one
if ( is_array( $final_url ) ) {
$final_url = $final_url[ array_rand( $final_url ) ];
}
// Now lets replace CDN url
foreach ( $this->_cfg_url_ori as $v ) {
if ( false !== strpos( $v, '*' ) ) {
$url = preg_replace( '#' . $scheme . $v . '#iU', $final_url, $url );
} else {
$url = str_replace( $scheme . $v, $final_url, $url );
}
}
self::debug2( '-rewritten: ' . $url );
return $url;
}
/**
* Check if the given URL matches any configured "original" URLs for CDN.
*
* @since 2.1
* @access private
*
* @param string $url URL to test.
* @return bool True if URL is one of the originals.
*/
private function _is_ori_url( $url ) {
$url_parsed = wp_parse_url( $url );
$scheme = ! empty( $url_parsed['scheme'] ) ? $url_parsed['scheme'] . ':' : '';
foreach ( $this->_cfg_url_ori as $v ) {
$needle = $scheme . $v;
if ( false !== strpos( $v, '*' ) ) {
if ( preg_match( '#' . $needle . '#iU', $url ) ) {
return true;
}
} elseif ( 0 === strpos( $url, $needle ) ) {
return true;
}
}
return false;
}
/**
* Check if the host is one of the CDN mapping hosts.
*
* @since 1.2.3
*
* @param string $host Hostname to check.
* @return bool False when bypassed, otherwise true if internal CDN host.
*/
public static function internal( $host ) {
if ( defined( self::BYPASS ) ) {
return false;
}
$instance = self::cls();
return in_array( $host, $instance->cdn_mapping_hosts, true ); // todo: can add $this->_is_ori_url() check in future
}
}