xref: /dokuwiki/lib/exe/fetch.php (revision 14bc69e3e1db81c4d329a140cb0e095f0dcf9b5e) 
1<?php
2/**
3 * DokuWiki media passthrough file
4 *
5 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
6 * @author     Andreas Gohr <andi@splitbrain.org>
7 */
8
9if(!defined('DOKU_INC')) define('DOKU_INC', dirname(__FILE__).'/../../');
10define('DOKU_DISABLE_GZIP_OUTPUT', 1);
11require_once(DOKU_INC.'inc/init.php');
12session_write_close(); //close session
13
14// BEGIN main (if not testing)
15if(!defined('SIMPLE_TEST')) {
16    $mimetypes = getMimeTypes();
17
18    //get input
19    $MEDIA  = stripctl(getID('media', false)); // no cleaning except control chars - maybe external
20    $CACHE  = calc_cache($INPUT->str('cache'));
21    $WIDTH  = $INPUT->int('w');
22    $HEIGHT = $INPUT->int('h');
23    $REV    = & $INPUT->ref('rev');
24    //sanitize revision
25    $REV = preg_replace('/[^0-9]/', '', $REV);
26
27    list($EXT, $MIME, $DL) = mimetype($MEDIA, false);
28    if($EXT === false) {
29        $EXT  = 'unknown';
30        $MIME = 'application/octet-stream';
31        $DL   = true;
32    }
33
34    // check for permissions, preconditions and cache external files
35    list($STATUS, $STATUSMESSAGE) = checkFileStatus($MEDIA, $FILE, $REV);
36
37    // prepare data for plugin events
38    $data = array(
39        'media'         => $MEDIA,
40        'file'          => $FILE,
41        'orig'          => $FILE,
42        'mime'          => $MIME,
43        'download'      => $DL,
44        'cache'         => $CACHE,
45        'ext'           => $EXT,
46        'width'         => $WIDTH,
47        'height'        => $HEIGHT,
48        'status'        => $STATUS,
49        'statusmessage' => $STATUSMESSAGE,
50        'ispublic'      => media_ispublic($MEDIA),
51    );
52
53    // handle the file status
54    $evt = new Doku_Event('FETCH_MEDIA_STATUS', $data);
55    if($evt->advise_before()) {
56        // redirects
57        if($data['status'] > 300 && $data['status'] <= 304) {
58            send_redirect($data['statusmessage']);
59        }
60        // send any non 200 status
61        if($data['status'] != 200) {
62            http_status($data['status'], $data['statusmessage']);
63        }
64        // die on errors
65        if($data['status'] > 203) {
66            print $data['statusmessage'];
67            exit;
68        }
69    }
70    $evt->advise_after();
71    unset($evt);
72
73    //handle image resizing/cropping
74    if((substr($MIME, 0, 5) == 'image') && $WIDTH) {
75        if($HEIGHT) {
76            $data['file'] = $FILE = media_crop_image($data['file'], $EXT, $WIDTH, $HEIGHT);
77        } else {
78            $data['file'] = $FILE = media_resize_image($data['file'], $EXT, $WIDTH, $HEIGHT);
79        }
80    }
81
82    // finally send the file to the client
83    $evt = new Doku_Event('MEDIA_SENDFILE', $data);
84    if($evt->advise_before()) {
85        sendFile($data['file'], $data['mime'], $data['download'], $data['cache'], $data['ispublic']);
86    }
87    // Do something after the download finished.
88    $evt->advise_after();  // will not be emitted on 304 or x-sendfile
89
90}// END DO main
91
92/* ------------------------------------------------------------------------ */
93
94/**
95 * Set headers and send the file to the client
96 *
97 * The $cache parameter influences how long files may be kept in caches, the $public parameter
98 * influences if this caching may happen in public proxis or in the browser cache only FS#2734
99 *
100 * This function will abort the current script when a 304 is sent or file sending is handled
101 * through x-sendfile
102 *
103 * @author Andreas Gohr <andi@splitbrain.org>
104 * @author Ben Coburn <btcoburn@silicodon.net>
105 * @param string $file   local file to send
106 * @param string $mime   mime type of the file
107 * @param bool   $dl     set to true to force a browser download
108 * @param int    $cache  remaining cache time in seconds (-1 for $conf['cache'], 0 for no-cache)
109 * @param bool   $public is this a public ressource or a private one?
110 */
111function sendFile($file, $mime, $dl, $cache, $public = false) {
112    global $conf;
113    // send mime headers
114    header("Content-Type: $mime");
115
116    // calculate cache times
117    if($cache == -1) {
118        $maxage  = max($conf['cachetime'], 3600); // cachetime or one hour
119        $expires = time() + $maxage;
120    } else if($cache > 0) {
121        $maxage  = $cache; // given time
122        $expires = time() + $maxage;
123    } else { // $cache == 0
124        $maxage  = 0;
125        $expires = 0; // 1970-01-01
126    }
127
128    // smart http caching headers
129    if($maxage) {
130        if($public) {
131            // cache publically
132            header('Expires: '.gmdate("D, d M Y H:i:s", $expires).' GMT');
133            header('Cache-Control: public, proxy-revalidate, no-transform, max-age='.$maxage);
134            header('Pragma: public');
135        } else {
136            // cache in browser
137            header('Expires: '.gmdate("D, d M Y H:i:s", $expires).' GMT');
138            header('Cache-Control: private, no-transform, max-age='.$maxage);
139            header('Pragma: no-cache');
140        }
141    } else {
142        // no cache at all
143        header('Expires: Thu, 01 Jan 1970 00:00:00 GMT');
144        header('Cache-Control: no-cache, no-transform');
145        header('Pragma: no-cache');
146    }
147
148    //send important headers first, script stops here if '304 Not Modified' response
149    $fmtime = @filemtime($file);
150    http_conditionalRequest($fmtime);
151
152    //download or display?
153    if($dl) {
154        header('Content-Disposition: attachment; filename="'.utf8_basename($file).'";');
155    } else {
156        header('Content-Disposition: inline; filename="'.utf8_basename($file).'";');
157    }
158
159    //use x-sendfile header to pass the delivery to compatible webservers
160    if(http_sendfile($file)) exit;
161
162    // send file contents
163    $fp = @fopen($file, "rb");
164    if($fp) {
165        http_rangeRequest($fp, filesize($file), $mime);
166    } else {
167        http_status(500);
168        print "Could not read $file - bad permissions?";
169    }
170}
171
172/**
173 * Check for media for preconditions and return correct status code
174 *
175 * READ: MEDIA, MIME, EXT, CACHE
176 * WRITE: MEDIA, FILE, array( STATUS, STATUSMESSAGE )
177 *
178 * @author Gerry Weissbach <gerry.w@gammaproduction.de>
179 * @param $media reference to the media id
180 * @param $file  reference to the file variable
181 * @returns array(STATUS, STATUSMESSAGE)
182 */
183function checkFileStatus(&$media, &$file, $rev = '') {
184    global $MIME, $EXT, $CACHE, $INPUT;
185
186    //media to local file
187    if(preg_match('#^(https?)://#i', $media)) {
188        //check hash
189        if(substr(md5(auth_cookiesalt().$media), 0, 6) !== $INPUT->str('hash')) {
190            return array(412, 'Precondition Failed');
191        }
192        //handle external images
193        if(strncmp($MIME, 'image/', 6) == 0) $file = media_get_from_URL($media, $EXT, $CACHE);
194        if(!$file) {
195            //download failed - redirect to original URL
196            return array(302, $media);
197        }
198    } else {
199        $media = cleanID($media);
200        if(empty($media)) {
201            return array(400, 'Bad request');
202        }
203
204        //check permissions (namespace only)
205        if(auth_quickaclcheck(getNS($media).':X') < AUTH_READ) {
206            return array(403, 'Forbidden');
207        }
208        $file = mediaFN($media, $rev);
209    }
210
211    //check file existance
212    if(!@file_exists($file)) {
213        return array(404, 'Not Found');
214    }
215
216    return array(200, null);
217}
218
219/**
220 * Returns the wanted cachetime in seconds
221 *
222 * Resolves named constants
223 *
224 * @author  Andreas Gohr <andi@splitbrain.org>
225 */
226function calc_cache($cache) {
227    global $conf;
228
229    if(strtolower($cache) == 'nocache') return 0; //never cache
230    if(strtolower($cache) == 'recache') return $conf['cachetime']; //use standard cache
231    return -1; //cache endless
232}
233
234//Setup VIM: ex: et ts=2 :
235