xref: /dokuwiki/inc/fetch.functions.php (revision 3dc2d50c5fda9c4bf708ff4c26e266ba239af62c) 
1<?php
2/**
3 * Functions used by lib/exe/fetch.php
4 * (not included by other parts of dokuwiki)
5 */
6
7/**
8 * Set headers and send the file to the client
9 *
10 * The $cache parameter influences how long files may be kept in caches, the $public parameter
11 * influences if this caching may happen in public proxis or in the browser cache only FS#2734
12 *
13 * This function will abort the current script when a 304 is sent or file sending is handled
14 * through x-sendfile
15 *
16 * @author Andreas Gohr <andi@splitbrain.org>
17 * @author Ben Coburn <btcoburn@silicodon.net>
18 * @author Gerry Weissbach <dokuwiki@gammaproduction.de>
19 *
20 * @param string $file   local file to send
21 * @param string $mime   mime type of the file
22 * @param bool   $dl     set to true to force a browser download
23 * @param int    $cache  remaining cache time in seconds (-1 for $conf['cache'], 0 for no-cache)
24 * @param bool   $public is this a public ressource or a private one?
25 * @param string $orig   original file to send - the file name will be used for the Content-Disposition
26 */
27function sendFile($file, $mime, $dl, $cache, $public = false, $orig = null) {
28    global $conf;
29    // send mime headers
30    header("Content-Type: $mime");
31
32    // calculate cache times
33    if($cache == -1) {
34        $maxage  = max($conf['cachetime'], 3600); // cachetime or one hour
35        $expires = time() + $maxage;
36    } else if($cache > 0) {
37        $maxage  = $cache; // given time
38        $expires = time() + $maxage;
39    } else { // $cache == 0
40        $maxage  = 0;
41        $expires = 0; // 1970-01-01
42    }
43
44    // smart http caching headers
45    if($maxage) {
46        if($public) {
47            // cache publically
48            header('Expires: '.gmdate("D, d M Y H:i:s", $expires).' GMT');
49            header('Cache-Control: public, proxy-revalidate, no-transform, max-age='.$maxage);
50        } else {
51            // cache in browser
52            header('Expires: '.gmdate("D, d M Y H:i:s", $expires).' GMT');
53            header('Cache-Control: private, no-transform, max-age='.$maxage);
54        }
55    } else {
56        // no cache at all
57        header('Expires: Thu, 01 Jan 1970 00:00:00 GMT');
58        header('Cache-Control: no-cache, no-transform');
59    }
60
61    //send important headers first, script stops here if '304 Not Modified' response
62    $fmtime = @filemtime($file);
63    http_conditionalRequest($fmtime);
64
65    // Use the current $file if is $orig is not set.
66    if ( $orig == null ) {
67        $orig = $file;
68    }
69
70    //download or display?
71    if($dl) {
72        header('Content-Disposition: attachment;'.rfc2231_encode('filename', utf8_basename($orig)).';');
73    } else {
74        header('Content-Disposition: inline;'.rfc2231_encode('filename', utf8_basename($orig)).';');
75    }
76
77    //use x-sendfile header to pass the delivery to compatible webservers
78    http_sendfile($file);
79
80    // send file contents
81    $fp = @fopen($file, "rb");
82    if($fp) {
83        http_rangeRequest($fp, filesize($file), $mime);
84    } else {
85        http_status(500);
86        print "Could not read $file - bad permissions?";
87    }
88}
89
90/**
91 * Try an rfc2231 compatible encoding. This ensures correct
92 * interpretation of filenames outside of the ASCII set.
93 * This seems to be needed for file names with e.g. umlauts that
94 * would otherwise decode wrongly in IE.
95 *
96 * There is no additional checking, just the encoding and setting the key=value for usage in headers
97 *
98 * @author Gerry Weissbach <gerry.w@gammaproduction.de>
99 * @param string $name      name of the field to be set in the header() call
100 * @param string $value     value of the field to be set in the header() call
101 * @param string $charset   used charset for the encoding of value
102 * @param string $lang      language used.
103 * @return string           in the format " name=value" for values WITHOUT special characters
104 * @return string           in the format " name*=charset'lang'value" for values WITH special characters
105 */
106function rfc2231_encode($name, $value, $charset='utf-8', $lang='en') {
107    $internal = preg_replace_callback(
108        '/[\x00-\x20*\'%()<>@,;:\\\\"\/[\]?=\x80-\xFF]/',
109        function ($match) {
110            return rawurlencode($match[0]);
111        },
112        $value
113    );
114    if ( $value != $internal ) {
115        return ' '.$name.'*='.$charset."'".$lang."'".$internal;
116    } else {
117        return ' '.$name.'="'.$value.'"';
118    }
119}
120
121/**
122 * Check for media for preconditions and return correct status code
123 *
124 * READ: MEDIA, MIME, EXT, CACHE
125 * WRITE: MEDIA, FILE, array( STATUS, STATUSMESSAGE )
126 *
127 * @author Gerry Weissbach <gerry.w@gammaproduction.de>
128 *
129 * @param string $media  reference to the media id
130 * @param string $file   reference to the file variable
131 * @param string $rev
132 * @param int    $width
133 * @param int    $height
134 * @return array as array(STATUS, STATUSMESSAGE)
135 */
136function checkFileStatus(&$media, &$file, $rev = '', $width=0, $height=0) {
137    global $MIME, $EXT, $CACHE, $INPUT;
138
139    //media to local file
140    if(media_isexternal($media)) {
141        //check token for external image and additional for resized and cached images
142        if(media_get_token($media, $width, $height) !== $INPUT->str('tok')) {
143            return array(412, 'Precondition Failed');
144        }
145        //handle external images
146        if(strncmp($MIME, 'image/', 6) == 0) $file = media_get_from_URL($media, $EXT, $CACHE);
147        if(!$file) {
148            //download failed - redirect to original URL
149            return array(302, $media);
150        }
151    } else {
152        $media = cleanID($media);
153        if(empty($media)) {
154            return array(400, 'Bad request');
155        }
156        // check token for resized images
157        if (($width || $height) && media_get_token($media, $width, $height) !== $INPUT->str('tok')) {
158            return array(412, 'Precondition Failed');
159        }
160
161        //check permissions (namespace only)
162        if(auth_quickaclcheck(getNS($media).':X') < AUTH_READ) {
163            return array(403, 'Forbidden');
164        }
165        $file = mediaFN($media, $rev);
166    }
167
168    //check file existance
169    if(!file_exists($file)) {
170        return array(404, 'Not Found');
171    }
172
173    return array(200, null);
174}
175
176/**
177 * Returns the wanted cachetime in seconds
178 *
179 * Resolves named constants
180 *
181 * @author  Andreas Gohr <andi@splitbrain.org>
182 *
183 * @param string $cache
184 * @return int cachetime in seconds
185 */
186function calc_cache($cache) {
187    global $conf;
188
189    if(strtolower($cache) == 'nocache') return 0; //never cache
190    if(strtolower($cache) == 'recache') return $conf['cachetime']; //use standard cache
191    return -1; //cache endless
192}
193