xref: /dokuwiki/inc/httputils.php (revision 2ab296805f9b647d3fe46cad4a7f275c45f171a8) 
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 != $last_modified) {
52        return; // if-modified-since is there but doesn't match
53    }
54
55    // Nothing has changed since their last request - serve a 304 and exit
56    header('HTTP/1.0 304 Not Modified');
57
58    // don't produce output, even if compression is on
59    @ob_end_clean();
60    exit;
61}
62
63/**
64 * Let the webserver send the given file vi x-sendfile method
65 *
66 * @author Chris Smith <chris.eureka@jalakai.co.uk>
67 * @returns  void or exits with previously header() commands executed
68 */
69function http_sendfile($file) {
70    global $conf;
71
72    //use x-sendfile header to pass the delivery to compatible webservers
73    if($conf['xsendfile'] == 1){
74        header("X-LIGHTTPD-send-file: $file");
75        ob_end_clean();
76        exit;
77    }elseif($conf['xsendfile'] == 2){
78        header("X-Sendfile: $file");
79        ob_end_clean();
80        exit;
81    }elseif($conf['xsendfile'] == 3){
82        header("X-Accel-Redirect: $file");
83        ob_end_clean();
84        exit;
85    }
86
87    return false;
88}
89
90/**
91 * Send file contents supporting rangeRequests
92 *
93 * This function exits the running script
94 *
95 * @param ressource $fh - file handle for an already open file
96 * @param int $size     - size of the whole file
97 * @param int $mime     - MIME type of the file
98 *
99 * @author Andreas Gohr <andi@splitbrain.org>
100 */
101function http_rangeRequest($fh,$size,$mime){
102    $ranges  = array();
103    $isrange = false;
104
105    header('Accept-Ranges: bytes');
106
107    if(!isset($_SERVER['HTTP_RANGE'])){
108        // no range requested - send the whole file
109        $ranges[] = array(0,$size,$size);
110    }else{
111        $t = explode('=', $_SERVER['HTTP_RANGE']);
112        if (!$t[0]=='bytes') {
113            // we only understand byte ranges - send the whole file
114            $ranges[] = array(0,$size,$size);
115        }else{
116            $isrange = true;
117            // handle multiple ranges
118            $r = explode(',',$t[1]);
119            foreach($r as $x){
120                $p = explode('-', $x);
121                $start = (int)$p[0];
122                $end   = (int)$p[1];
123                if (!$end) $end = $size - 1;
124                if ($start > $end || $start > $size || $end > $size){
125                    header('HTTP/1.1 416 Requested Range Not Satisfiable');
126                    print 'Bad Range Request!';
127                    exit;
128                }
129                $len = $end - $start + 1;
130                $ranges[] = array($start,$end,$len);
131            }
132        }
133    }
134    $parts = count($ranges);
135
136    // now send the type and length headers
137    if(!$isrange){
138        header("Content-Type: $mime",true);
139    }else{
140        header('HTTP/1.1 206 Partial Content');
141        if($parts == 1){
142            header("Content-Type: $mime",true);
143        }else{
144            header('Content-Type: multipart/byteranges; boundary='.HTTP_MULTIPART_BOUNDARY,true);
145        }
146    }
147
148    // send all ranges
149    for($i=0; $i<$parts; $i++){
150        list($start,$end,$len) = $ranges[$i];
151
152        // multipart or normal headers
153        if($parts > 1){
154            echo HTTP_HEADER_LF.'--'.HTTP_MULTIPART_BOUNDARY.HTTP_HEADER_LF;
155            echo "Content-Type: $mime".HTTP_HEADER_LF;
156            echo "Content-Range: bytes $start-$end/$size".HTTP_HEADER_LF;
157            echo HTTP_HEADER_LF;
158        }else{
159            header("Content-Length: $len");
160            if($isrange){
161                header("Content-Range: bytes $start-$end/$size");
162            }
163        }
164
165        // send file content
166        fseek($fh,$start); //seek to start of range
167        $chunk = ($len > HTTP_CHUNK_SIZE) ? HTTP_CHUNK_SIZE : $len;
168        while (!feof($fh) && $chunk > 0) {
169            @set_time_limit(30); // large files can take a lot of time
170            print fread($fh, $chunk);
171            flush();
172            $len -= $chunk;
173            $chunk = ($len > HTTP_CHUNK_SIZE) ? HTTP_CHUNK_SIZE : $len;
174        }
175    }
176    if($parts > 1){
177        echo HTTP_HEADER_LF.'--'.HTTP_MULTIPART_BOUNDARY.'--'.HTTP_HEADER_LF;
178    }
179
180    // everything should be done here, exit
181    exit;
182}
183
184/**
185 * Check for a gzipped version and create if necessary
186 *
187 * return true if there exists a gzip version of the uncompressed file
188 * (samepath/samefilename.sameext.gz) created after the uncompressed file
189 *
190 * @author Chris Smith <chris.eureka@jalakai.co.uk>
191 */
192function http_gzip_valid($uncompressed_file) {
193    $gzip = $uncompressed_file.'.gz';
194    if (filemtime($gzip) < filemtime($uncompressed_file)) {    // filemtime returns false (0) if file doesn't exist
195        return copy($uncompressed_file, 'compress.zlib://'.$gzip);
196    }
197
198    return true;
199}
200
201/**
202 * Set HTTP headers and echo cachefile, if useable
203 *
204 * This function handles output of cacheable resource files. It ses the needed
205 * HTTP headers. If a useable cache is present, it is passed to the web server
206 * and the scrpt is terminated.
207 */
208function http_cached($cache, $cache_ok) {
209    global $conf;
210
211    // check cache age & handle conditional request
212    // since the resource files are timestamped, we can use a long max age: 1 year
213    header('Cache-Control: public, max-age=31536000');
214    header('Pragma: public');
215    if($cache_ok){
216        http_conditionalRequest(filemtime($cache));
217        if($conf['allowdebug']) header("X-CacheUsed: $cache");
218
219        // finally send output
220        if ($conf['gzip_output'] && http_gzip_valid($cache)) {
221            header('Vary: Accept-Encoding');
222            header('Content-Encoding: gzip');
223            readfile($cache.".gz");
224        } else {
225            if (!http_sendfile($cache)) readfile($cache);
226        }
227        exit;
228    }
229
230    http_conditionalRequest(time());
231}
232
233/**
234 * Cache content and print it
235 */
236function http_cached_finish($file, $content) {
237    global $conf;
238
239    // save cache file
240    io_saveFile($file, $content);
241    if(function_exists('gzopen')) io_saveFile("$file.gz",$content);
242
243    // finally send output
244    if ($conf['gzip_output']) {
245        header('Vary: Accept-Encoding');
246        header('Content-Encoding: gzip');
247        print gzencode($content,9,FORCE_GZIP);
248    } else {
249        print $content;
250    }
251}
252
253/**
254 * Fetches raw, unparsed POST data
255 *
256 * @return string
257 */
258function http_get_raw_post_data() {
259    static $postData = null;
260    if ($postData === null) {
261        $postData = file_get_contents('php://input');
262    }
263    return $postData;
264}
265
266/**
267 * Set the HTTP response status and takes care of the used PHP SAPI
268 *
269 * Inspired by CodeIgniter's set_status_header function
270 *
271 * @param int    $code
272 * @param string $text
273 */
274function http_status($code = 200, $text = '') {
275    static $stati = array(
276        200 => 'OK',
277        201 => 'Created',
278        202 => 'Accepted',
279        203 => 'Non-Authoritative Information',
280        204 => 'No Content',
281        205 => 'Reset Content',
282        206 => 'Partial Content',
283
284        300 => 'Multiple Choices',
285        301 => 'Moved Permanently',
286        302 => 'Found',
287        304 => 'Not Modified',
288        305 => 'Use Proxy',
289        307 => 'Temporary Redirect',
290
291        400 => 'Bad Request',
292        401 => 'Unauthorized',
293        403 => 'Forbidden',
294        404 => 'Not Found',
295        405 => 'Method Not Allowed',
296        406 => 'Not Acceptable',
297        407 => 'Proxy Authentication Required',
298        408 => 'Request Timeout',
299        409 => 'Conflict',
300        410 => 'Gone',
301        411 => 'Length Required',
302        412 => 'Precondition Failed',
303        413 => 'Request Entity Too Large',
304        414 => 'Request-URI Too Long',
305        415 => 'Unsupported Media Type',
306        416 => 'Requested Range Not Satisfiable',
307        417 => 'Expectation Failed',
308
309        500 => 'Internal Server Error',
310        501 => 'Not Implemented',
311        502 => 'Bad Gateway',
312        503 => 'Service Unavailable',
313        504 => 'Gateway Timeout',
314        505 => 'HTTP Version Not Supported'
315    );
316
317    if($text == '' && isset($stati[$code])) {
318        $text = $stati[$code];
319    }
320
321    $server_protocol = (isset($_SERVER['SERVER_PROTOCOL'])) ? $_SERVER['SERVER_PROTOCOL'] : false;
322
323    if(substr(php_sapi_name(), 0, 3) == 'cgi') {
324        header("Status: {$code} {$text}", true);
325    } elseif($server_protocol == 'HTTP/1.1' OR $server_protocol == 'HTTP/1.0') {
326        header($server_protocol." {$code} {$text}", true, $code);
327    } else {
328        header("HTTP/1.1 {$code} {$text}", true, $code);
329    }
330}
331