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   1  <?php
   2  
   3  /**
   4   * Utilities for handling HTTP related tasks
   5   *
   6   * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
   7   * @author     Andreas Gohr <andi@splitbrain.org>
   8   */
   9  
  10  define('HTTP_MULTIPART_BOUNDARY', 'D0KuW1K1B0uNDARY');
  11  define('HTTP_HEADER_LF', "\r\n");
  12  define('HTTP_CHUNK_SIZE', 16 * 1024);
  13  
  14  /**
  15   * Checks and sets HTTP headers for conditional HTTP requests
  16   *
  17   * @param int $timestamp lastmodified time of the cache file
  18   * @returns  void or exits with previously header() commands executed
  19   * @link     http://simonwillison.net/2003/Apr/23/conditionalGet/
  20   *
  21   * @author   Simon Willison <swillison@gmail.com>
  22   */
  23  function http_conditionalRequest($timestamp)
  24  {
  25      global $INPUT;
  26  
  27      // A PHP implementation of conditional get, see
  28      //   http://fishbowl.pastiche.org/2002/10/21/http_conditional_get_for_rss_hackers/
  29      $last_modified = substr(gmdate('r', $timestamp), 0, -5) . 'GMT';
  30      $etag = '"' . md5($last_modified) . '"';
  31      // Send the headers
  32      header("Last-Modified: $last_modified");
  33      header("ETag: $etag");
  34      // See if the client has provided the required headers
  35      $if_modified_since = $INPUT->server->filter('stripslashes')->str('HTTP_IF_MODIFIED_SINCE', false);
  36      $if_none_match = $INPUT->server->filter('stripslashes')->str('HTTP_IF_NONE_MATCH', false);
  37  
  38      if (!$if_modified_since && !$if_none_match) {
  39          return;
  40      }
  41  
  42      // At least one of the headers is there - check them
  43      if ($if_none_match && $if_none_match != $etag) {
  44          return; // etag is there but doesn't match
  45      }
  46  
  47      if ($if_modified_since && $if_modified_since != $last_modified) {
  48          return; // if-modified-since is there but doesn't match
  49      }
  50  
  51      // Nothing has changed since their last request - serve a 304 and exit
  52      header('HTTP/1.0 304 Not Modified');
  53  
  54      // don't produce output, even if compression is on
  55      @ob_end_clean();
  56      exit;
  57  }
  58  
  59  /**
  60   * Let the webserver send the given file via x-sendfile method
  61   *
  62   * @param string $file absolute path of file to send
  63   * @returns  void or exits with previous header() commands executed
  64   * @author Chris Smith <chris@jalakai.co.uk>
  65   *
  66   */
  67  function http_sendfile($file)
  68  {
  69      global $conf;
  70  
  71      //use x-sendfile header to pass the delivery to compatible web servers
  72      if ($conf['xsendfile'] == 1) {
  73          header("X-LIGHTTPD-send-file: $file");
  74          ob_end_clean();
  75          exit;
  76      } elseif ($conf['xsendfile'] == 2) {
  77          header("X-Sendfile: $file");
  78          ob_end_clean();
  79          exit;
  80      } elseif ($conf['xsendfile'] == 3) {
  81          // FS#2388 nginx just needs the relative path.
  82          $file = DOKU_REL . substr($file, strlen(fullpath(DOKU_INC)) + 1);
  83          header("X-Accel-Redirect: $file");
  84          ob_end_clean();
  85          exit;
  86      }
  87  }
  88  
  89  /**
  90   * Send file contents supporting rangeRequests
  91   *
  92   * This function exits the running script
  93   *
  94   * @param resource $fh - file handle for an already open file
  95   * @param int $size - size of the whole file
  96   * @param int $mime - MIME type of the file
  97   *
  98   * @author Andreas Gohr <andi@splitbrain.org>
  99   */
 100  function http_rangeRequest($fh, $size, $mime)
 101  {
 102      global $INPUT;
 103  
 104      $ranges = [];
 105      $isrange = false;
 106  
 107      header('Accept-Ranges: bytes');
 108  
 109      if (!$INPUT->server->has('HTTP_RANGE')) {
 110          // no range requested - send the whole file
 111          $ranges[] = [0, $size, $size];
 112      } else {
 113          $t = explode('=', $INPUT->server->str('HTTP_RANGE'));
 114          if (!$t[0] == 'bytes') {
 115              // we only understand byte ranges - send the whole file
 116              $ranges[] = [0, $size, $size];
 117          } else {
 118              $isrange = true;
 119              // handle multiple ranges
 120              $r = explode(',', $t[1]);
 121              foreach ($r as $x) {
 122                  $p = explode('-', $x);
 123                  $start = (int)$p[0];
 124                  $end = (int)$p[1];
 125                  if (!$end) $end = $size - 1;
 126                  if ($start > $end || $start > $size || $end > $size) {
 127                      header('HTTP/1.1 416 Requested Range Not Satisfiable');
 128                      echo 'Bad Range Request!';
 129                      exit;
 130                  }
 131                  $len = $end - $start + 1;
 132                  $ranges[] = [$start, $end, $len];
 133              }
 134          }
 135      }
 136      $parts = count($ranges);
 137  
 138      // now send the type and length headers
 139      if (!$isrange) {
 140          header("Content-Type: $mime", true);
 141      } else {
 142          header('HTTP/1.1 206 Partial Content');
 143          if ($parts == 1) {
 144              header("Content-Type: $mime", true);
 145          } else {
 146              header('Content-Type: multipart/byteranges; boundary=' . HTTP_MULTIPART_BOUNDARY, true);
 147          }
 148      }
 149  
 150      // send all ranges
 151      for ($i = 0; $i < $parts; $i++) {
 152          [$start, $end, $len] = $ranges[$i];
 153  
 154          // multipart or normal headers
 155          if ($parts > 1) {
 156              echo HTTP_HEADER_LF . '--' . HTTP_MULTIPART_BOUNDARY . HTTP_HEADER_LF;
 157              echo "Content-Type: $mime" . HTTP_HEADER_LF;
 158              echo "Content-Range: bytes $start-$end/$size" . HTTP_HEADER_LF;
 159              echo HTTP_HEADER_LF;
 160          } else {
 161              header("Content-Length: $len");
 162              if ($isrange) {
 163                  header("Content-Range: bytes $start-$end/$size");
 164              }
 165          }
 166  
 167          // send file content
 168          fseek($fh, $start); //seek to start of range
 169          $chunk = ($len > HTTP_CHUNK_SIZE) ? HTTP_CHUNK_SIZE : $len;
 170          while (!feof($fh) && $chunk > 0) {
 171              @set_time_limit(30); // large files can take a lot of time
 172              echo fread($fh, $chunk);
 173              flush();
 174              $len -= $chunk;
 175              $chunk = ($len > HTTP_CHUNK_SIZE) ? HTTP_CHUNK_SIZE : $len;
 176          }
 177      }
 178      if ($parts > 1) {
 179          echo HTTP_HEADER_LF . '--' . HTTP_MULTIPART_BOUNDARY . '--' . HTTP_HEADER_LF;
 180      }
 181  
 182      // everything should be done here, exit (or return if testing)
 183      if (defined('SIMPLE_TEST')) return;
 184      exit;
 185  }
 186  
 187  /**
 188   * Check for a gzipped version and create if necessary
 189   *
 190   * return true if there exists a gzip version of the uncompressed file
 191   * (samepath/samefilename.sameext.gz) created after the uncompressed file
 192   *
 193   * @param string $uncompressed_file
 194   * @return bool
 195   * @author Chris Smith <chris.eureka@jalakai.co.uk>
 196   *
 197   */
 198  function http_gzip_valid($uncompressed_file)
 199  {
 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  {
 222      global $conf;
 223  
 224      // check cache age & handle conditional request
 225      // since the resource files are timestamped, we can use a long max age: 1 year
 226      header('Cache-Control: public, max-age=31536000');
 227      header('Pragma: public');
 228      if ($cache_ok) {
 229          http_conditionalRequest(filemtime($cache));
 230          if ($conf['allowdebug']) header("X-CacheUsed: $cache");
 231  
 232          // finally send output
 233          if ($conf['gzip_output'] && http_gzip_valid($cache)) {
 234              header('Vary: Accept-Encoding');
 235              header('Content-Encoding: gzip');
 236              readfile($cache . ".gz");
 237          } else {
 238              http_sendfile($cache);
 239              readfile($cache);
 240          }
 241          exit;
 242      }
 243  
 244      http_conditionalRequest(time());
 245  }
 246  
 247  /**
 248   * Cache content and print it
 249   *
 250   * @param string $file file name
 251   * @param string $content
 252   */
 253  function http_cached_finish($file, $content)
 254  {
 255      global $conf;
 256  
 257      // save cache file
 258      io_saveFile($file, $content);
 259      if (DOKU_HAS_GZIP) io_saveFile("$file.gz", $content);
 260  
 261      // finally send output
 262      if ($conf['gzip_output'] && DOKU_HAS_GZIP) {
 263          header('Vary: Accept-Encoding');
 264          header('Content-Encoding: gzip');
 265          echo gzencode($content, 9, FORCE_GZIP);
 266      } else {
 267          echo $content;
 268      }
 269  }
 270  
 271  /**
 272   * Fetches raw, unparsed POST data
 273   *
 274   * @return string
 275   */
 276  function http_get_raw_post_data()
 277  {
 278      static $postData = null;
 279      if ($postData === null) {
 280          $postData = file_get_contents('php://input');
 281      }
 282      return $postData;
 283  }
 284  
 285  /**
 286   * Set the HTTP response status and takes care of the used PHP SAPI
 287   *
 288   * Inspired by CodeIgniter's set_status_header function
 289   *
 290   * @param int $code
 291   * @param string $text
 292   */
 293  function http_status($code = 200, $text = '')
 294  {
 295      global $INPUT;
 296  
 297      static $stati = [
 298          200 => 'OK',
 299          201 => 'Created',
 300          202 => 'Accepted',
 301          203 => 'Non-Authoritative Information',
 302          204 => 'No Content',
 303          205 => 'Reset Content',
 304          206 => 'Partial Content',
 305          300 => 'Multiple Choices',
 306          301 => 'Moved Permanently',
 307          302 => 'Found',
 308          304 => 'Not Modified',
 309          305 => 'Use Proxy',
 310          307 => 'Temporary Redirect',
 311          400 => 'Bad Request',
 312          401 => 'Unauthorized',
 313          403 => 'Forbidden',
 314          404 => 'Not Found',
 315          405 => 'Method Not Allowed',
 316          406 => 'Not Acceptable',
 317          407 => 'Proxy Authentication Required',
 318          408 => 'Request Timeout',
 319          409 => 'Conflict',
 320          410 => 'Gone',
 321          411 => 'Length Required',
 322          412 => 'Precondition Failed',
 323          413 => 'Request Entity Too Large',
 324          414 => 'Request-URI Too Long',
 325          415 => 'Unsupported Media Type',
 326          416 => 'Requested Range Not Satisfiable',
 327          417 => 'Expectation Failed',
 328          500 => 'Internal Server Error',
 329          501 => 'Not Implemented',
 330          502 => 'Bad Gateway',
 331          503 => 'Service Unavailable',
 332          504 => 'Gateway Timeout',
 333          505 => 'HTTP Version Not Supported'
 334      ];
 335  
 336      if ($text == '' && isset($stati[$code])) {
 337          $text = $stati[$code];
 338      }
 339  
 340      $server_protocol = $INPUT->server->str('SERVER_PROTOCOL', false);
 341  
 342      if (str_starts_with(PHP_SAPI, 'cgi') || defined('SIMPLE_TEST')) {
 343          header("Status: {$code} {$text}", true);
 344      } elseif ($server_protocol == 'HTTP/1.1' || $server_protocol == 'HTTP/1.0') {
 345          header($server_protocol . " {$code} {$text}", true, $code);
 346      } else {
 347          header("HTTP/1.1 {$code} {$text}", true, $code);
 348      }
 349  }