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  * @param int $timestamp lastmodified time of the cache file
  17  * @returns  void or exits with previously header() commands executed
  18  * @link     http://simonwillison.net/2003/Apr/23/conditionalGet/
  19  *
  20  * @author   Simon Willison <swillison@gmail.com>
  21  */
  22 function http_conditionalRequest($timestamp)
  23 {
  24     global $INPUT;
  25
  26     // A PHP implementation of conditional get, see
  27     //   http://fishbowl.pastiche.org/2002/10/21/http_conditional_get_for_rss_hackers/
  28     $last_modified = substr(gmdate('r', $timestamp), 0, -5) . 'GMT';
  29     $etag = '"' . md5($last_modified) . '"';
  30     // Send the headers
  31     header("Last-Modified: $last_modified");
  32     header("ETag: $etag");
  33     // See if the client has provided the required headers
  34     $if_modified_since = $INPUT->server->filter('stripslashes')->str('HTTP_IF_MODIFIED_SINCE', false);
  35     $if_none_match = $INPUT->server->filter('stripslashes')->str('HTTP_IF_NONE_MATCH', false);
  36
  37     if (!$if_modified_since && !$if_none_match) {
  38         return;
  39     }
  40
  41     // At least one of the headers is there - check them
  42     if ($if_none_match && $if_none_match != $etag) {
  43         return; // etag is there but doesn't match
  44     }
  45
  46     if ($if_modified_since && $if_modified_since != $last_modified) {
  47         return; // if-modified-since is there but doesn't match
  48     }
  49
  50     // Nothing has changed since their last request - serve a 304 and exit
  51     header('HTTP/1.0 304 Not Modified');
  52
  53     // don't produce output, even if compression is on
  54     @ob_end_clean();
  55     exit;
  56 }
  57
  58 /**
  59  * Let the webserver send the given file via x-sendfile method
  60  *
  61  * @param string $file absolute path of file to send
  62  * @returns  void or exits with previous header() commands executed
  63  * @author Chris Smith <chris@jalakai.co.uk>
  64  *
  65  */
  66 function http_sendfile($file)
  67 {
  68     global $conf;
  69
  70     //use x-sendfile header to pass the delivery to compatible web servers
  71     if ($conf['xsendfile'] == 1) {
  72         header("X-LIGHTTPD-send-file: $file");
  73         ob_end_clean();
  74         exit;
  75     } elseif ($conf['xsendfile'] == 2) {
  76         header("X-Sendfile: $file");
  77         ob_end_clean();
  78         exit;
  79     } elseif ($conf['xsendfile'] == 3) {
  80         // FS#2388 nginx just needs the relative path.
  81         $file = DOKU_REL . substr($file, strlen(fullpath(DOKU_INC)) + 1);
  82         header("X-Accel-Redirect: $file");
  83         ob_end_clean();
  84         exit;
  85     }
  86 }
  87
  88 /**
  89  * Send file contents supporting rangeRequests
  90  *
  91  * This function exits the running script
  92  *
  93  * @param resource $fh - file handle for an already open file
  94  * @param int $size - size of the whole file
  95  * @param int $mime - MIME type of the file
  96  *
  97  * @author Andreas Gohr <andi@splitbrain.org>
  98  */
  99 function http_rangeRequest($fh, $size, $mime)
 100 {
 101     global $INPUT;
 102
 103     $ranges = [];
 104     $isrange = false;
 105
 106     header('Accept-Ranges: bytes');
 107
 108     if (!$INPUT->server->has('HTTP_RANGE')) {
 109         // no range requested - send the whole file
 110         $ranges[] = [0, $size, $size];
 111     } else {
 112         $t = explode('=', $INPUT->server->str('HTTP_RANGE'));
 113         if (!$t[0] == 'bytes') {
 114             // we only understand byte ranges - send the whole file
 115             $ranges[] = [0, $size, $size];
 116         } else {
 117             $isrange = true;
 118             // handle multiple ranges
 119             $r = explode(',', $t[1]);
 120             foreach ($r as $x) {
 121                 $p = explode('-', $x);
 122                 $start = (int)$p[0];
 123                 $end = (int)$p[1];
 124                 if (!$end) $end = $size - 1;
 125                 if ($start > $end || $start > $size || $end > $size) {
 126                     header('HTTP/1.1 416 Requested Range Not Satisfiable');
 127                     echo 'Bad Range Request!';
 128                     exit;
 129                 }
 130                 $len = $end - $start + 1;
 131                 $ranges[] = [$start, $end, $len];
 132             }
 133         }
 134     }
 135     $parts = count($ranges);
 136
 137     // now send the type and length headers
 138     if (!$isrange) {
 139         header("Content-Type: $mime", true);
 140     } else {
 141         header('HTTP/1.1 206 Partial Content');
 142         if ($parts == 1) {
 143             header("Content-Type: $mime", true);
 144         } else {
 145             header('Content-Type: multipart/byteranges; boundary=' . HTTP_MULTIPART_BOUNDARY, true);
 146         }
 147     }
 148
 149     // send all ranges
 150     for ($i = 0; $i < $parts; $i++) {
 151         [$start, $end, $len] = $ranges[$i];
 152
 153         // multipart or normal headers
 154         if ($parts > 1) {
 155             echo HTTP_HEADER_LF . '--' . HTTP_MULTIPART_BOUNDARY . HTTP_HEADER_LF;
 156             echo "Content-Type: $mime" . HTTP_HEADER_LF;
 157             echo "Content-Range: bytes $start-$end/$size" . HTTP_HEADER_LF;
 158             echo HTTP_HEADER_LF;
 159         } else {
 160             header("Content-Length: $len");
 161             if ($isrange) {
 162                 header("Content-Range: bytes $start-$end/$size");
 163             }
 164         }
 165
 166         // send file content
 167         fseek($fh, $start); //seek to start of range
 168         $chunk = ($len > HTTP_CHUNK_SIZE) ? HTTP_CHUNK_SIZE : $len;
 169         while (!feof($fh) && $chunk > 0) {
 170             @set_time_limit(30); // large files can take a lot of time
 171             echo fread($fh, $chunk);
 172             flush();
 173             $len -= $chunk;
 174             $chunk = ($len > HTTP_CHUNK_SIZE) ? HTTP_CHUNK_SIZE : $len;
 175         }
 176     }
 177     if ($parts > 1) {
 178         echo HTTP_HEADER_LF . '--' . HTTP_MULTIPART_BOUNDARY . '--' . HTTP_HEADER_LF;
 179     }
 180
 181     // everything should be done here, exit (or return if testing)
 182     if (defined('SIMPLE_TEST')) return;
 183     exit;
 184 }
 185
 186 /**
 187  * Check for a gzipped version and create if necessary
 188  *
 189  * return true if there exists a gzip version of the uncompressed file
 190  * (samepath/samefilename.sameext.gz) created after the uncompressed file
 191  *
 192  * @param string $uncompressed_file
 193  * @return bool
 194  * @author Chris Smith <chris.eureka@jalakai.co.uk>
 195  *
 196  */
 197 function http_gzip_valid($uncompressed_file)
 198 {
 199     if (!DOKU_HAS_GZIP) return false;
 200
 201     $gzip = $uncompressed_file . '.gz';
 202     if (filemtime($gzip) < filemtime($uncompressed_file)) {    // filemtime returns false (0) if file doesn't exist
 203         return copy($uncompressed_file, 'compress.zlib://' . $gzip);
 204     }
 205
 206     return true;
 207 }
 208
 209 /**
 210  * Set HTTP headers and echo cachefile, if useable
 211  *
 212  * This function handles output of cacheable resource files. It ses the needed
 213  * HTTP headers. If a useable cache is present, it is passed to the web server
 214  * and the script is terminated.
 215  *
 216  * @param string $cache cache file name
 217  * @param bool $cache_ok if cache can be used
 218  */
 219 function http_cached($cache, $cache_ok)
 220 {
 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 {
 254     global $conf;
 255
 256     // save cache file
 257     io_saveFile($file, $content);
 258     if (DOKU_HAS_GZIP) io_saveFile("$file.gz", $content);
 259
 260     // finally send output
 261     if ($conf['gzip_output'] && DOKU_HAS_GZIP) {
 262         header('Vary: Accept-Encoding');
 263         header('Content-Encoding: gzip');
 264         echo gzencode($content, 9, FORCE_GZIP);
 265     } else {
 266         echo $content;
 267     }
 268 }
 269
 270 /**
 271  * Fetches raw, unparsed POST data
 272  *
 273  * @return string
 274  */
 275 function http_get_raw_post_data()
 276 {
 277     static $postData = null;
 278     if ($postData === null) {
 279         $postData = file_get_contents('php://input');
 280     }
 281     return $postData;
 282 }
 283
 284 /**
 285  * Set the HTTP response status and takes care of the used PHP SAPI
 286  *
 287  * Inspired by CodeIgniter's set_status_header function
 288  *
 289  * @param int $code
 290  * @param string $text
 291  */
 292 function http_status($code = 200, $text = '')
 293 {
 294     global $INPUT;
 295
 296     static $stati = [
 297         200 => 'OK',
 298         201 => 'Created',
 299         202 => 'Accepted',
 300         203 => 'Non-Authoritative Information',
 301         204 => 'No Content',
 302         205 => 'Reset Content',
 303         206 => 'Partial Content',
 304         300 => 'Multiple Choices',
 305         301 => 'Moved Permanently',
 306         302 => 'Found',
 307         304 => 'Not Modified',
 308         305 => 'Use Proxy',
 309         307 => 'Temporary Redirect',
 310         400 => 'Bad Request',
 311         401 => 'Unauthorized',
 312         403 => 'Forbidden',
 313         404 => 'Not Found',
 314         405 => 'Method Not Allowed',
 315         406 => 'Not Acceptable',
 316         407 => 'Proxy Authentication Required',
 317         408 => 'Request Timeout',
 318         409 => 'Conflict',
 319         410 => 'Gone',
 320         411 => 'Length Required',
 321         412 => 'Precondition Failed',
 322         413 => 'Request Entity Too Large',
 323         414 => 'Request-URI Too Long',
 324         415 => 'Unsupported Media Type',
 325         416 => 'Requested Range Not Satisfiable',
 326         417 => 'Expectation Failed',
 327         500 => 'Internal Server Error',
 328         501 => 'Not Implemented',
 329         502 => 'Bad Gateway',
 330         503 => 'Service Unavailable',
 331         504 => 'Gateway Timeout',
 332         505 => 'HTTP Version Not Supported'
 333     ];
 334
 335     if ($text == '' && isset($stati[$code])) {
 336         $text = $stati[$code];
 337     }
 338
 339     $server_protocol = $INPUT->server->str('SERVER_PROTOCOL', false);
 340
 341     if (substr(PHP_SAPI, 0, 3) == 'cgi' || defined('SIMPLE_TEST')) {
 342         header("Status: {$code} {$text}", true);
 343     } elseif ($server_protocol == 'HTTP/1.1' || $server_protocol == 'HTTP/1.0') {
 344         header($server_protocol . " {$code} {$text}", true, $code);
 345     } else {
 346         header("HTTP/1.1 {$code} {$text}", true, $code);
 347     }
 348 }