inc/httputils.php

   1 <?php
   2 /**
   3  * Utilities for handling HTTP related tasks
   4  *
   5  * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
   6  * @author     Andreas Gohr <andi@splitbrain.org>
   7  */
   8
   9 define('HTTP_MULTIPART_BOUNDARY','D0KuW1K1B0uNDARY');
  10 define('HTTP_HEADER_LF',"\r\n");
  11 define('HTTP_CHUNK_SIZE',16*1024);
  12
  13 /**
  14  * Checks and sets HTTP headers for conditional HTTP requests
  15  *
  16  * @author   Simon Willison <swillison@gmail.com>
  17  * @link     http://simonwillison.net/2003/Apr/23/conditionalGet/
  18  *
  19  * @param    int $timestamp lastmodified time of the cache file
  20  * @returns  void or exits with previously header() commands executed
  21  */
  22 function http_conditionalRequest($timestamp){
  23     // A PHP implementation of conditional get, see
  24     //   http://fishbowl.pastiche.org/2002/10/21/http_conditional_get_for_rss_hackers/
  25     $last_modified = substr(gmdate('r', $timestamp), 0, -5).'GMT';
  26     $etag = '"'.md5($last_modified).'"';
  27     // Send the headers
  28     header("Last-Modified: $last_modified");
  29     header("ETag: $etag");
  30     // See if the client has provided the required headers
  31     if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])){
  32         $if_modified_since = stripslashes($_SERVER['HTTP_IF_MODIFIED_SINCE']);
  33     }else{
  34         $if_modified_since = false;
  35     }
  36
  37     if (isset($_SERVER['HTTP_IF_NONE_MATCH'])){
  38         $if_none_match = stripslashes($_SERVER['HTTP_IF_NONE_MATCH']);
  39     }else{
  40         $if_none_match = false;
  41     }
  42
  43     if (!$if_modified_since && !$if_none_match){
  44         return;
  45     }
  46
  47     // At least one of the headers is there - check them
  48     if ($if_none_match && $if_none_match != $etag) {
  49         return; // etag is there but doesn't match
  50     }
  51
  52     if ($if_modified_since && $if_modified_since != $last_modified) {
  53         return; // if-modified-since is there but doesn't match
  54     }
  55
  56     // Nothing has changed since their last request - serve a 304 and exit
  57     header('HTTP/1.0 304 Not Modified');
  58
  59     // don't produce output, even if compression is on
  60     @ob_end_clean();
  61     exit;
  62 }
  63
  64 /**
  65  * Let the webserver send the given file via x-sendfile method
  66  *
  67  * @author Chris Smith <chris@jalakai.co.uk>
  68  *
  69  * @param string $file absolute path of file to send
  70  * @returns  void or exits with previous header() commands executed
  71  */
  72 function http_sendfile($file) {
  73     global $conf;
  74
  75     //use x-sendfile header to pass the delivery to compatible web servers
  76     if($conf['xsendfile'] == 1){
  77         header("X-LIGHTTPD-send-file: $file");
  78         ob_end_clean();
  79         exit;
  80     }elseif($conf['xsendfile'] == 2){
  81         header("X-Sendfile: $file");
  82         ob_end_clean();
  83         exit;
  84     }elseif($conf['xsendfile'] == 3){
  85         // FS#2388 nginx just needs the relative path.
  86         $file = DOKU_REL.substr($file, strlen(fullpath(DOKU_INC)) + 1);
  87         header("X-Accel-Redirect: $file");
  88         ob_end_clean();
  89         exit;
  90     }
  91 }
  92
  93 /**
  94  * Send file contents supporting rangeRequests
  95  *
  96  * This function exits the running script
  97  *
  98  * @param resource $fh - file handle for an already open file
  99  * @param int $size     - size of the whole file
 100  * @param int $mime     - MIME type of the file
 101  *
 102  * @author Andreas Gohr <andi@splitbrain.org>
 103  */
 104 function http_rangeRequest($fh,$size,$mime){
 105     $ranges  = array();
 106     $isrange = false;
 107
 108     header('Accept-Ranges: bytes');
 109
 110     if(!isset($_SERVER['HTTP_RANGE'])){
 111         // no range requested - send the whole file
 112         $ranges[] = array(0,$size,$size);
 113     }else{
 114         $t = explode('=', $_SERVER['HTTP_RANGE']);
 115         if (!$t[0]=='bytes') {
 116             // we only understand byte ranges - send the whole file
 117             $ranges[] = array(0,$size,$size);
 118         }else{
 119             $isrange = true;
 120             // handle multiple ranges
 121             $r = explode(',',$t[1]);
 122             foreach($r as $x){
 123                 $p = explode('-', $x);
 124                 $start = (int)$p[0];
 125                 $end   = (int)$p[1];
 126                 if (!$end) $end = $size - 1;
 127                 if ($start > $end || $start > $size || $end > $size){
 128                     header('HTTP/1.1 416 Requested Range Not Satisfiable');
 129                     print 'Bad Range Request!';
 130                     exit;
 131                 }
 132                 $len = $end - $start + 1;
 133                 $ranges[] = array($start,$end,$len);
 134             }
 135         }
 136     }
 137     $parts = count($ranges);
 138
 139     // now send the type and length headers
 140     if(!$isrange){
 141         header("Content-Type: $mime",true);
 142     }else{
 143         header('HTTP/1.1 206 Partial Content');
 144         if($parts == 1){
 145             header("Content-Type: $mime",true);
 146         }else{
 147             header('Content-Type: multipart/byteranges; boundary='.HTTP_MULTIPART_BOUNDARY,true);
 148         }
 149     }
 150
 151     // send all ranges
 152     for($i=0; $i<$parts; $i++){
 153         list($start,$end,$len) = $ranges[$i];
 154
 155         // multipart or normal headers
 156         if($parts > 1){
 157             echo HTTP_HEADER_LF.'--'.HTTP_MULTIPART_BOUNDARY.HTTP_HEADER_LF;
 158             echo "Content-Type: $mime".HTTP_HEADER_LF;
 159             echo "Content-Range: bytes $start-$end/$size".HTTP_HEADER_LF;
 160             echo HTTP_HEADER_LF;
 161         }else{
 162             header("Content-Length: $len");
 163             if($isrange){
 164                 header("Content-Range: bytes $start-$end/$size");
 165             }
 166         }
 167
 168         // send file content
 169         fseek($fh,$start); //seek to start of range
 170         $chunk = ($len > HTTP_CHUNK_SIZE) ? HTTP_CHUNK_SIZE : $len;
 171         while (!feof($fh) && $chunk > 0) {
 172             @set_time_limit(30); // large files can take a lot of time
 173             print fread($fh, $chunk);
 174             flush();
 175             $len -= $chunk;
 176             $chunk = ($len > HTTP_CHUNK_SIZE) ? HTTP_CHUNK_SIZE : $len;
 177         }
 178     }
 179     if($parts > 1){
 180         echo HTTP_HEADER_LF.'--'.HTTP_MULTIPART_BOUNDARY.'--'.HTTP_HEADER_LF;
 181     }
 182
 183     // everything should be done here, exit (or return if testing)
 184     if (defined('SIMPLE_TEST')) return;
 185     exit;
 186 }
 187
 188 /**
 189  * Check for a gzipped version and create if necessary
 190  *
 191  * return true if there exists a gzip version of the uncompressed file
 192  * (samepath/samefilename.sameext.gz) created after the uncompressed file
 193  *
 194  * @author Chris Smith <chris.eureka@jalakai.co.uk>
 195  *
 196  * @param string $uncompressed_file
 197  * @return bool
 198  */
 199 function http_gzip_valid($uncompressed_file) {
 200     if(!DOKU_HAS_GZIP) return false;
 201
 202     $gzip = $uncompressed_file.'.gz';
 203     if (filemtime($gzip) < filemtime($uncompressed_file)) {    // filemtime returns false (0) if file doesn't exist
 204         return copy($uncompressed_file, 'compress.zlib://'.$gzip);
 205     }
 206
 207     return true;
 208 }
 209
 210 /**
 211  * Set HTTP headers and echo cachefile, if useable
 212  *
 213  * This function handles output of cacheable resource files. It ses the needed
 214  * HTTP headers. If a useable cache is present, it is passed to the web server
 215  * and the script is terminated.
 216  *
 217  * @param string $cache cache file name
 218  * @param bool   $cache_ok    if cache can be used
 219  */
 220 function http_cached($cache, $cache_ok) {
 221     global $conf;
 222
 223     // check cache age & handle conditional request
 224     // since the resource files are timestamped, we can use a long max age: 1 year
 225     header('Cache-Control: public, max-age=31536000');
 226     header('Pragma: public');
 227     if($cache_ok){
 228         http_conditionalRequest(filemtime($cache));
 229         if($conf['allowdebug']) header("X-CacheUsed: $cache");
 230
 231         // finally send output
 232         if ($conf['gzip_output'] && http_gzip_valid($cache)) {
 233             header('Vary: Accept-Encoding');
 234             header('Content-Encoding: gzip');
 235             readfile($cache.".gz");
 236         } else {
 237             http_sendfile($cache);
 238             readfile($cache);
 239         }
 240         exit;
 241     }
 242
 243     http_conditionalRequest(time());
 244 }
 245
 246 /**
 247  * Cache content and print it
 248  *
 249  * @param string $file file name
 250  * @param string $content
 251  */
 252 function http_cached_finish($file, $content) {
 253     global $conf;
 254
 255     // save cache file
 256     io_saveFile($file, $content);
 257     if(DOKU_HAS_GZIP) io_saveFile("$file.gz",$content);
 258
 259     // finally send output
 260     if ($conf['gzip_output'] && DOKU_HAS_GZIP) {
 261         header('Vary: Accept-Encoding');
 262         header('Content-Encoding: gzip');
 263         print gzencode($content,9,FORCE_GZIP);
 264     } else {
 265         print $content;
 266     }
 267 }
 268
 269 /**
 270  * Fetches raw, unparsed POST data
 271  *
 272  * @return string
 273  */
 274 function http_get_raw_post_data() {
 275     static $postData = null;
 276     if ($postData === null) {
 277         $postData = file_get_contents('php://input');
 278     }
 279     return $postData;
 280 }
 281
 282 /**
 283  * Set the HTTP response status and takes care of the used PHP SAPI
 284  *
 285  * Inspired by CodeIgniter's set_status_header function
 286  *
 287  * @param int    $code
 288  * @param string $text
 289  */
 290 function http_status($code = 200, $text = '') {
 291     static $stati = array(
 292         200 => 'OK',
 293         201 => 'Created',
 294         202 => 'Accepted',
 295         203 => 'Non-Authoritative Information',
 296         204 => 'No Content',
 297         205 => 'Reset Content',
 298         206 => 'Partial Content',
 299
 300         300 => 'Multiple Choices',
 301         301 => 'Moved Permanently',
 302         302 => 'Found',
 303         304 => 'Not Modified',
 304         305 => 'Use Proxy',
 305         307 => 'Temporary Redirect',
 306
 307         400 => 'Bad Request',
 308         401 => 'Unauthorized',
 309         403 => 'Forbidden',
 310         404 => 'Not Found',
 311         405 => 'Method Not Allowed',
 312         406 => 'Not Acceptable',
 313         407 => 'Proxy Authentication Required',
 314         408 => 'Request Timeout',
 315         409 => 'Conflict',
 316         410 => 'Gone',
 317         411 => 'Length Required',
 318         412 => 'Precondition Failed',
 319         413 => 'Request Entity Too Large',
 320         414 => 'Request-URI Too Long',
 321         415 => 'Unsupported Media Type',
 322         416 => 'Requested Range Not Satisfiable',
 323         417 => 'Expectation Failed',
 324
 325         500 => 'Internal Server Error',
 326         501 => 'Not Implemented',
 327         502 => 'Bad Gateway',
 328         503 => 'Service Unavailable',
 329         504 => 'Gateway Timeout',
 330         505 => 'HTTP Version Not Supported'
 331     );
 332
 333     if($text == '' && isset($stati[$code])) {
 334         $text = $stati[$code];
 335     }
 336
 337     $server_protocol = (isset($_SERVER['SERVER_PROTOCOL'])) ? $_SERVER['SERVER_PROTOCOL'] : false;
 338
 339     if(substr(php_sapi_name(), 0, 3) == 'cgi' || defined('SIMPLE_TEST')) {
 340         header("Status: {$code} {$text}", true);
 341     } elseif($server_protocol == 'HTTP/1.1' OR $server_protocol == 'HTTP/1.0') {
 342         header($server_protocol." {$code} {$text}", true, $code);
 343     } else {
 344         header("HTTP/1.1 {$code} {$text}", true, $code);
 345     }
 346 }