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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      // 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  }