default user agent

.htaccess

@@ -1,5 +1,5 @@
-<FilesMatch "config\.php">
+<FilesMatch "^(?!index\.php$).+\.php$">
-  Order allow,deny
+  Order deny,allow
   Deny from all
 </FilesMatch>
 

README.md

@@ -11,7 +11,11 @@ This software should make it simple to use pre-rendered map tiles in your own pr
 
 Download project files and upload it into your web hosting of your choice.
 
-Open the **"test.html"** file within your browser, your proxy server should display you a simple slippy maps rendering default Open Street Map tiles.
+<p align="center">
+    <a href="https://raruto.github.io" rel="nofollow"><img src="https://raruto.github.io/img/proxy-caching.jpg" alt="Proxy Caching" /></a>
+</p>
+
+Open the **"test.html"** file within your browser, the proxy server should display you a simple slippy map rendering the default Open Street Map tiles.
 Or test directly  in your browser with a tile URL such as: http://www.example.com/tiles/15/17024/10792.png
 
 **NB.** Remeber to check your web server folder permissions: **777** or **755**
@@ -27,6 +31,13 @@ Or test directly  in your browser with a tile URL such as: http://www.example.co
 1. **edit the default "config.php"**
 
     ```php
+    /**
+     * Public App name.
+     *
+     * @var string
+     */
+    $config['user_agent'] = 'Tile-Proxy-PHP/0.1';
+
     /**
      * Whitelist of supported tile servers
      *

config.php

@@ -8,6 +8,13 @@
  * @license   https://www.gnu.org/licenses/gpl-3.0.txt GNU/GPLv3
  */
 
+/**
+ * Public App name.
+ *
+ * @var string
+ */
+$config['user_agent'] = 'Tile-Proxy-PHP/0.1';
+
 /**
  * Whitelist of supported tile servers
  *

functions.php

@@ -0,0 +1,285 @@
+<?php
+/**
+ * Map Tile PHP Proxy Functions
+ *
+ * @package   tile-proxy-php
+ * @author    Raruto <raruto.github.io>
+ * @link      https://github.com/Raruto/tile-proxy-php
+ * @license   https://www.gnu.org/licenses/gpl-3.0.txt GNU/GPLv3
+ */
+
+/**
+ * Generate a real tile server url
+ *
+ * @param  string $url eg: 'https://{switch:a,b,c}.tile.openstreetmap.org/{z}/{x}/{y}.png'.
+ * @return string      eg: 'https://a.tile.openstreetmap.org/0/0/0.png'.
+ */
+function generate_tile_server_url( $url ) {
+	global $z, $x, $y;
+	$has_matches = preg_match( '/{switch:(.*?)}/', $url, $domains );
+	if ( ! $has_matches ) {
+		$domains = [ '', '' ];
+	}
+	$domains = explode( ',', $domains[1] );
+	$url     = preg_replace( '/{switch:(.*?)}/', '{s}', $url );
+	$url     = preg_replace( '/{s}/', $domains[ array_rand( $domains ) ], $url );
+	$url     = preg_replace( '/{z}/', $z, $url );
+	$url     = preg_replace( '/{x}/', $x, $url );
+	$url     = preg_replace( '/{y}/', $y, $url );
+	return $url;
+}
+
+/**
+ * Convert Map Degrees to Radiant
+ *
+ * @param  float $deg map degrees.
+ * @return float
+ */
+function deg_to_rad( $deg ) {
+	return $deg * M_PI / 180;
+}
+/**
+ * Convert Map Longitude to Tile-X Coordinates
+ *
+ * @param  float $lng  map longitude.
+ * @param  int   $zoom map zoom level.
+ * @return int
+ */
+function lng_to_tile_x( $lng, $zoom ) {
+	return floor( ( ( $lng + 180 ) / 360 ) * pow( 2, $zoom ) );
+}
+
+/**
+ * Convert Map Latitude to Tile-Y Coordinates
+ *
+ * @param  float $lat  map latitude.
+ * @param  int   $zoom map zoom level.
+ * @return int
+ */
+function lat_to_tile_y( $lat, $zoom ) {
+	return floor( ( 1 - log( tan( deg_to_rad( $lat ) ) + 1 / cos( deg_to_rad( $lat ) ) ) / M_PI ) / 2 * pow( 2, $zoom ) );
+}
+/**
+ * Finds if a number is within a given range
+ *
+ * @param  float $number number to check.
+ * @param  float $min   left range number.
+ * @param  float $max   right range number.
+ * @return bool
+ */
+function in_range( $number, $min, $max ) {
+		return $number >= $min && $number <= $max;
+}
+
+/**
+ * Check if cached file is expired
+ *
+ * @param  string $file filename path.
+ * @return bool
+ */
+function is_file_expired( $file ) {
+	global $ttl;
+	return filemtime( $file ) < time() - ( $ttl * 30 );
+}
+
+/**
+ * Check if a remote resource exists
+ *
+ * @param  string $url remote file url.
+ * @return bool
+ */
+function remote_file_exists( $url ) {
+	$ch = curl_init( $url );
+	curl_setopt( $ch, CURLOPT_NOBODY, true );
+	curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, true );
+	curl_exec( $ch );
+	$http_code = curl_getinfo( $ch, CURLINFO_HTTP_CODE );
+	curl_close( $ch );
+	if ( $http_code == 200 ) {
+		return true;
+	}
+	return false;
+}
+
+/**
+ * Download a remote resource
+ *
+ * @param  string $url    remote file url.
+ * @param  string $folder folder where to download the remote resource.
+ * @param  string $file   file onto download the remote resource.
+ * @return void
+ */
+function download_remote_file( $url, $folder, $file ) {
+	global $user_agent;
+
+	if ( ! is_dir( $folder ) ) {
+		mkdir( $folder, 0755, true );
+	}
+
+	$fp = fopen( $file, 'wb' );
+
+	$ch = curl_init( $url );
+	curl_setopt( $ch, CURLOPT_FILE, $fp );
+	curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, true );
+	curl_setopt( $ch, CURLOPT_HEADER, 0 );
+	curl_setopt( $ch, CURLOPT_USERAGENT, $user_agent );
+
+	if ( is_localhost() ) {
+		curl_setopt( $ch, CURLOPT_SSL_VERIFYHOST, false );
+		curl_setopt( $ch, CURLOPT_SSL_VERIFYPEER, false );
+	}
+
+	curl_exec( $ch );
+	curl_close( $ch );
+
+	fflush( $fp ); // need to insert this line for proper output when tile is first requested.
+	fclose( $fp );
+}
+
+/**
+ * Output a local file
+ *
+ * @param  string $file file of the local resource.
+ * @return void
+ */
+function output_local_file( $file ) {
+	print_local_file_headers( $file );
+	readfile( $file );
+}
+
+/**
+ * Proxy a remote resource
+ *
+ * @param  string $url    remote file url.
+ * @return void
+ */
+function proxy_remote_file( $url ) {
+	global $user_agent;
+
+	$context = stream_context_create(
+		array(
+			'http' => array(
+				'method'     => 'GET',
+				'user_agent' => $user_agent,
+			),
+		)
+	);
+
+	$fp = @fopen( $url, 'rb', false, $context );
+	if ( ! $fp ) {
+		print_404_page();
+		return;
+	}
+	print_remote_file_headers( $url );
+	fpassthru( $fp );
+}
+
+/**
+ * Get remote file headers, similar to: get_headers( $url )
+ *
+ * @param  string $url    remote file url.
+ * @return array
+ * @link https://stackoverflow.com/a/41135574
+ */
+function get_remote_file_headers( $url ) {
+	global $user_agent;
+
+	$headers = [];
+	$ch      = curl_init();
+
+	curl_setopt( $ch, CURLOPT_URL, $url );
+	curl_setopt( $ch, CURLOPT_HEADER, true );
+	curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, true );
+	curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1 );
+	curl_setopt( $ch, CURLOPT_USERAGENT, $user_agent );
+
+	if ( is_localhost() ) {
+		curl_setopt( $ch, CURLOPT_SSL_VERIFYHOST, false );
+		curl_setopt( $ch, CURLOPT_SSL_VERIFYPEER, false );
+	}
+
+	// this function is called by curl for each header received.
+	curl_setopt(
+		$ch, CURLOPT_HEADERFUNCTION,
+		function( $curl, $header ) use ( &$headers ) {
+			$headers[] = $header;
+			return strlen( $header );
+		}
+	);
+	curl_exec( $ch );
+	curl_close( $ch );
+
+	return $headers;
+}
+
+/**
+ * Check if this a local Server instance.
+ */
+function is_localhost() {
+	$server_addr = isset( $_SERVER['REMOTE_ADDR'] ) ? $_SERVER['REMOTE_ADDR'] : null;
+	return in_array( $server_addr, [ '127.0.0.1', '::1' ], true );
+}
+
+/**
+ * Print the default apache 404 page
+ *
+ * @return void
+ */
+function print_404_page() {
+	header( $_SERVER['SERVER_PROTOCOL'] . ' 404 Not Found' );
+	$request_uri = htmlspecialchars( $_SERVER['REQUEST_URI'] );
+	echo '<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">';
+	echo "<html><head><title>404 Not Found</title></head><body><h1>Not Found</h1><p>The requested URL {$request_uri} was not found on this server.</p></body></html>";
+}
+
+/**
+ * Send to browser remote file headers
+ *
+ * @param  string $url    remote file url.
+ * @return void
+ */
+function print_remote_file_headers( $url ) {
+	$headers = get_remote_file_headers( $url );
+	print_file_headers( $headers );
+}
+
+/**
+ * Send to browser local file headers
+ *
+ * @param  string $file    local file.
+ * @return void
+ */
+function print_local_file_headers( $file ) {
+	global $ttl;
+	$headers = array(
+		'Expires:'       => gmdate( 'D, d M Y H:i:s', time() + $ttl * 60 ) . ' GMT',
+		'Last-Modified:' => gmdate( 'D, d M Y H:i:s', filemtime( $file ) ) . ' GMT',
+		'Cache-Control:' => 'public, max-age=' . ( $ttl * 60 ), // for MSIE 5.
+		'Content-Type:'  => 'image/png',
+	);
+	print_file_headers( $headers );
+}
+
+/**
+ * Send to browser file headers filtering it with the previously array in config file
+ *
+ * @param array $file_headers eg: array( 'Content-Type:'  => 'image/png' ) or array( 'Access-Control-Allow-Origin: *' ).
+ *
+ * @return void
+ */
+function print_file_headers( &$file_headers ) {
+	global $headers;
+	// send headers only if not previously defined in config file.
+	foreach ( $file_headers as $header => $value ) {
+		if ( is_string( $header ) ) {
+			header( $header . ' ' . $value );
+		} else {
+			header( $value );
+		}
+	}
+	// send all remaing default headers defined in config file.
+	foreach ( $headers as $header => $value ) {
+		header_remove( rtrim( $header, ':' ) );
+		header( $header . ' ' . $value );
+	}
+}

index.php

@@ -15,12 +15,13 @@
  * @license   https://www.gnu.org/licenses/gpl-3.0.txt GNU/GPLv3
  */
 
-// TODO: code refactoring ( wrap it within a dedicated class.. )
-
 // User configs.
 require_once 'config.php';
+// Tile functions.
+require_once 'functions.php';
 
 // Default configs.
+$user_agent = @$config['user_agent'] ?: 'Tile-Proxy-PHP/0.1';
 $servers    = @$config['servers'] ?: array(
 	'osm' => 'https://{switch:a,b,c}.tile.openstreetmap.org/{z}/{x}/{y}.png',
 	'otm' => 'https://{switch:a,b,c}.tile.opentopomap.org/{z}/{x}/{y}.png',
@@ -81,248 +82,3 @@ if ( ! is_file( $file ) || ( is_file_expired( $file ) && remote_file_exists( $ur
 // Send to browser any previously cached tile.
 output_local_file( $file );
 exit;
-
-/* // functions ///////////////////////////////////////////////////////////// */
-
-/**
- * Generate a real tile server url
- *
- * @param  string $url eg: 'https://{switch:a,b,c}.tile.openstreetmap.org/{z}/{x}/{y}.png'.
- * @return string      eg: 'https://a.tile.openstreetmap.org/0/0/0.png'.
- */
-function generate_tile_server_url( $url ) {
-	global $z, $x, $y;
-	$has_matches = preg_match( '/{switch:(.*?)}/', $url, $domains );
-	if ( ! $has_matches ) {
-		$domains = [ '', '' ];
-	}
-	$domains = explode( ',', $domains[1] );
-	$url     = preg_replace( '/{switch:(.*?)}/', '{s}', $url );
-	$url     = preg_replace( '/{s}/', $domains[ array_rand( $domains ) ], $url );
-	$url     = preg_replace( '/{z}/', $z, $url );
-	$url     = preg_replace( '/{x}/', $x, $url );
-	$url     = preg_replace( '/{y}/', $y, $url );
-	return $url;
-}
-
-/**
- * Convert Map Degrees to Radiant
- *
- * @param  float $deg map degrees.
- * @return float
- */
-function deg_to_rad( $deg ) {
-	return $deg * M_PI / 180;
-}
-/**
- * Convert Map Longitude to Tile-X Coordinates
- *
- * @param  float $lng  map longitude.
- * @param  int   $zoom map zoom level.
- * @return int
- */
-function lng_to_tile_x( $lng, $zoom ) {
-	return floor( ( ( $lng + 180 ) / 360 ) * pow( 2, $zoom ) );
-}
-
-/**
- * Convert Map Latitude to Tile-Y Coordinates
- *
- * @param  float $lat  map latitude.
- * @param  int   $zoom map zoom level.
- * @return int
- */
-function lat_to_tile_y( $lat, $zoom ) {
-	return floor( ( 1 - log( tan( deg_to_rad( $lat ) ) + 1 / cos( deg_to_rad( $lat ) ) ) / M_PI ) / 2 * pow( 2, $zoom ) );
-}
-/**
- * Finds if a number is within a given range
- *
- * @param  float $number number to check.
- * @param  float $min   left range number.
- * @param  float $max   right range number.
- * @return bool
- */
-function in_range( $number, $min, $max ) {
-		return $number >= $min && $number <= $max;
-}
-
-/**
- * Check if cached file is expired
- *
- * @param  string $file filename path.
- * @return bool
- */
-function is_file_expired( $file ) {
-	global $ttl;
-	return filemtime( $file ) < time() - ( $ttl * 30 );
-}
-
-/**
- * Check if a remote resource exists
- *
- * @param  string $url remote file url.
- * @return bool
- */
-function remote_file_exists( $url ) {
-	$ch = curl_init( $url );
-	curl_setopt( $ch, CURLOPT_NOBODY, true );
-	curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, true );
-	curl_exec( $ch );
-	$http_code = curl_getinfo( $ch, CURLINFO_HTTP_CODE );
-	curl_close( $ch );
-	if ( $http_code == 200 ) {
-		return true;
-	}
-	return false;
-}
-
-/**
- * Download a remote resource
- *
- * @param  string $url    remote file url.
- * @param  string $folder folder where to download the remote resource.
- * @param  string $file   file onto download the remote resource.
- * @return void
- */
-function download_remote_file( $url, $folder, $file ) {
-	if ( ! is_dir( $folder ) ) {
-		mkdir( $folder, 0755, true );
-	}
-
-	$fp = fopen( $file, 'wb' );
-
-	$ch = curl_init( $url );
-	curl_setopt( $ch, CURLOPT_FILE, $fp );
-	curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, true );
-	curl_setopt( $ch, CURLOPT_HEADER, 0 );
-	curl_exec( $ch );
-	curl_close( $ch );
-
-	fflush( $fp ); // need to insert this line for proper output when tile is first requested.
-	fclose( $fp );
-}
-
-/**
- * Output a local file
- *
- * @param  string $file file of the local resource.
- * @return void
- */
-function output_local_file( $file ) {
-	print_local_file_headers( $file );
-	readfile( $file );
-}
-
-/**
- * Proxy a remote resource
- *
- * @param  string $url    remote file url.
- * @return void
- */
-function proxy_remote_file( $url ) {
-	$fp = @fopen( $url, 'rb' );
-	if ( ! $fp ) {
-		print_404_page();
-		return;
-	}
-	print_remote_file_headers( $url );
-	fpassthru( $fp );
-}
-
-/**
- * Get remote file headers, similar to: get_headers( $url )
- *
- * @param  string $url    remote file url.
- * @return array
- * @link https://stackoverflow.com/a/41135574
- */
-function get_remote_file_headers( $url ) {
-	$headers = [];
-	$ch      = curl_init();
-
-	curl_setopt( $ch, CURLOPT_URL, $url );
-	curl_setopt( $ch, CURLOPT_HEADER, true );
-	curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, true );
-	curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1 );
-
-	// this function is called by curl for each header received.
-	curl_setopt(
-		$ch, CURLOPT_HEADERFUNCTION,
-		function( $curl, $header ) use ( &$headers ) {
-			$headers[] = $header;
-			return strlen( $header );
-		}
-	);
-	curl_exec( $ch );
-	curl_close( $ch );
-
-	return $headers;
-}
-
-/**
- * Print the default apache 404 page
- *
- * @return void
- */
-function print_404_page() {
-	header( $_SERVER['SERVER_PROTOCOL'] . ' 404 Not Found' );
-	$request_uri = htmlspecialchars( $_SERVER['REQUEST_URI'] );
-	echo '<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">';
-	echo "<html><head><title>404 Not Found</title></head><body><h1>Not Found</h1><p>The requested URL {$request_uri} was not found on this server.</p></body></html>";
-}
-
-/**
- * Send to browser remote file headers
- *
- * @param  string $url    remote file url.
- * @return void
- */
-function print_remote_file_headers( $url ) {
-	$headers = get_remote_file_headers( $url );
-	print_file_headers( $headers );
-}
-
-/**
- * Send to browser local file headers
- *
- * @param  string $file    local file.
- * @return void
- */
-function print_local_file_headers( $file ) {
-	global $ttl;
-	$exp_gmt = gmdate( 'D, d M Y H:i:s', time() + $ttl * 60 ) . ' GMT';
-	$mod_gmt = gmdate( 'D, d M Y H:i:s', filemtime( $file ) ) . ' GMT';
-	$max_age = $ttl * 60;
-	$headers = array(
-		'Expires:'       => $exp_gmt,
-		'Last-Modified:' => $mod_gmt,
-		'Cache-Control:' => 'public, max-age=' . $max_age, // for MSIE 5.
-		'Content-Type:'  => 'image/png',
-	);
-	print_file_headers( $headers );
-}
-
-/**
- * Send to browser file headers filtering it with the previously array in config file
- *
- * @param array $file_headers eg: array( 'Content-Type:'  => 'image/png' ) or array( 'Access-Control-Allow-Origin: *' ).
- *
- * @return void
- */
-function print_file_headers( &$file_headers ) {
-	global $headers;
-	// send headers only if not previously defined in config file.
-	foreach ( $file_headers as $header => $value ) {
-		if ( is_string( $header ) ) {
-			header( $header . ' ' . $value );
-		} else {
-			header( $value );
-		}
-	}
-	// send all remaing default headers defined in config file.
-	foreach ( $headers as $header => $value ) {
-		header_remove( rtrim( $header, ':' ) );
-		header( $header . ' ' . $value );
-	}
-}