xref: /dokuwiki/inc/httputils.php (revision 0b1e5003aae587074526c6b2ef19cb84670195e8) 
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
9define('HTTP_MULTIPART_BOUNDARY','D0KuW1K1B0uNDARY');
10define('HTTP_HEADER_LF',"\r\n");
11define('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 * @param    int $timestamp lastmodified time of the cache file
19 * @returns  void or exits with previously header() commands executed
20 */
21function http_conditionalRequest($timestamp){
22    // A PHP implementation of conditional get, see
23    //   http://fishbowl.pastiche.org/2002/10/21/http_conditional_get_for_rss_hackers/
24    $last_modified = substr(gmdate('r', $timestamp), 0, -5).'GMT';
25    $etag = '"'.md5($last_modified).'"';
26    // Send the headers
27    header("Last-Modified: $last_modified");
28    header("ETag: $etag");
29    // See if the client has provided the required headers
30    if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])){
31        $if_modified_since = stripslashes($_SERVER['HTTP_IF_MODIFIED_SINCE']);
32    }else{
33        $if_modified_since = false;
34    }
35
36    if (isset($_SERVER['HTTP_IF_NONE_MATCH'])){
37        $if_none_match = stripslashes($_SERVER['HTTP_IF_NONE_MATCH']);
38    }else{
39        $if_none_match = false;
40    }
41
42    if (!$if_modified_since && !$if_none_match){
43        return;
44    }
45
46    // At least one of the headers is there - check them
47    if ($if_none_match && $if_none_match != $etag) {
48        return; // etag is there but doesn't match
49    }
50
51    if ($if_modified_since && $if_modified_since != $last_modified) {
52        return; // if-modified-since is there but doesn't match
53    }
54
55    // Nothing has changed since their last request - serve a 304 and exit
56    header('HTTP/1.0 304 Not Modified');
57
58    // don't produce output, even if compression is on
59    @ob_end_clean();
60    exit;
61}
62
63/**
64 * Let the webserver send the given file via x-sendfile method
65 *
66 * @author Chris Smith <chris@jalakai.co.uk>
67 * @param $file
68 * @returns bool or exits with previously header() commands executed
69 */
70function http_sendfile($file) {
71    global $conf;
72
73    //use x-sendfile header to pass the delivery to compatible webservers
74    if($conf['xsendfile'] == 1){
75        header("X-LIGHTTPD-send-file: $file");
76        ob_end_clean();
77        exit;
78    }elseif($conf['xsendfile'] == 2){
79        header("X-Sendfile: $file");
80        ob_end_clean();
81        exit;
82    }elseif($conf['xsendfile'] == 3){
83        header("X-Accel-Redirect: $file");
84        ob_end_clean();
85        exit;
86    }
87
88    return false;
89}
90
91/**
92 * Send file contents supporting rangeRequests
93 *
94 * This function exits the running script
95 *
96 * @param resource $fh - file handle for an already open file
97 * @param int $size     - size of the whole file
98 * @param int $mime     - MIME type of the file
99 *
100 * @author Andreas Gohr <andi@splitbrain.org>
101 */
102function http_rangeRequest($fh,$size,$mime){
103    $ranges  = array();
104    $isrange = false;
105
106    header('Accept-Ranges: bytes');
107
108    if(!isset($_SERVER['HTTP_RANGE'])){
109        // no range requested - send the whole file
110        $ranges[] = array(0,$size,$size);
111    }else{
112        $t = explode('=', $_SERVER['HTTP_RANGE']);
113        if (!$t[0]=='bytes') {
114            // we only understand byte ranges - send the whole file
115            $ranges[] = array(0,$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                    print 'Bad Range Request!';
128                    exit;
129                }
130                $len = $end - $start + 1;
131                $ranges[] = array($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; $i++){
151        list($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) && $chunk > 0) {
170            @set_time_limit(30); // large files can take a lot of time
171            print fread($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 * @author Chris Smith <chris.eureka@jalakai.co.uk>
193 */
194function http_gzip_valid($uncompressed_file) {
195    $gzip = $uncompressed_file.'.gz';
196    if (filemtime($gzip) < filemtime($uncompressed_file)) {    // filemtime returns false (0) if file doesn't exist
197        return copy($uncompressed_file, 'compress.zlib://'.$gzip);
198    }
199
200    return true;
201}
202
203/**
204 * Set HTTP headers and echo cachefile, if useable
205 *
206 * This function handles output of cacheable resource files. It ses the needed
207 * HTTP headers. If a useable cache is present, it is passed to the web server
208 * and the script is terminated.
209 */
210function http_cached($cache, $cache_ok) {
211    global $conf;
212
213    // check cache age & handle conditional request
214    // since the resource files are timestamped, we can use a long max age: 1 year
215    header('Cache-Control: public, max-age=31536000');
216    header('Pragma: public');
217    if($cache_ok){
218        http_conditionalRequest(filemtime($cache));
219        if($conf['allowdebug']) header("X-CacheUsed: $cache");
220
221        // finally send output
222        if ($conf['gzip_output'] && http_gzip_valid($cache)) {
223            header('Vary: Accept-Encoding');
224            header('Content-Encoding: gzip');
225            readfile($cache.".gz");
226        } else {
227            if (!http_sendfile($cache)) readfile($cache);
228        }
229        exit;
230    }
231
232    http_conditionalRequest(time());
233}
234
235/**
236 * Cache content and print it
237 */
238function http_cached_finish($file, $content) {
239    global $conf;
240
241    // save cache file
242    io_saveFile($file, $content);
243    if(function_exists('gzopen')) io_saveFile("$file.gz",$content);
244
245    // finally send output
246    if ($conf['gzip_output']) {
247        header('Vary: Accept-Encoding');
248        header('Content-Encoding: gzip');
249        print gzencode($content,9,FORCE_GZIP);
250    } else {
251        print $content;
252    }
253}
254
255/**
256 * Fetches raw, unparsed POST data
257 *
258 * @return string
259 */
260function http_get_raw_post_data() {
261    static $postData = null;
262    if ($postData === null) {
263        $postData = file_get_contents('php://input');
264    }
265    return $postData;
266}
267
268/**
269 * Set the HTTP response status and takes care of the used PHP SAPI
270 *
271 * Inspired by CodeIgniter's set_status_header function
272 *
273 * @param int    $code
274 * @param string $text
275 */
276function http_status($code = 200, $text = '') {
277    static $stati = array(
278        200 => 'OK',
279        201 => 'Created',
280        202 => 'Accepted',
281        203 => 'Non-Authoritative Information',
282        204 => 'No Content',
283        205 => 'Reset Content',
284        206 => 'Partial Content',
285
286        300 => 'Multiple Choices',
287        301 => 'Moved Permanently',
288        302 => 'Found',
289        304 => 'Not Modified',
290        305 => 'Use Proxy',
291        307 => 'Temporary Redirect',
292
293        400 => 'Bad Request',
294        401 => 'Unauthorized',
295        403 => 'Forbidden',
296        404 => 'Not Found',
297        405 => 'Method Not Allowed',
298        406 => 'Not Acceptable',
299        407 => 'Proxy Authentication Required',
300        408 => 'Request Timeout',
301        409 => 'Conflict',
302        410 => 'Gone',
303        411 => 'Length Required',
304        412 => 'Precondition Failed',
305        413 => 'Request Entity Too Large',
306        414 => 'Request-URI Too Long',
307        415 => 'Unsupported Media Type',
308        416 => 'Requested Range Not Satisfiable',
309        417 => 'Expectation Failed',
310
311        500 => 'Internal Server Error',
312        501 => 'Not Implemented',
313        502 => 'Bad Gateway',
314        503 => 'Service Unavailable',
315        504 => 'Gateway Timeout',
316        505 => 'HTTP Version Not Supported'
317    );
318
319    if($text == '' && isset($stati[$code])) {
320        $text = $stati[$code];
321    }
322
323    $server_protocol = (isset($_SERVER['SERVER_PROTOCOL'])) ? $_SERVER['SERVER_PROTOCOL'] : false;
324
325    if(substr(php_sapi_name(), 0, 3) == 'cgi' || defined('SIMPLE_TEST')) {
326        header("Status: {$code} {$text}", true);
327    } elseif($server_protocol == 'HTTP/1.1' OR $server_protocol == 'HTTP/1.0') {
328        header($server_protocol." {$code} {$text}", true, $code);
329    } else {
330        header("HTTP/1.1 {$code} {$text}", true, $code);
331    }
332}
333