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