wd-link-dir.php

<?php

define('BASE_URL', '/dav/');
define('ROOT_PATH', '/mnt/storage2/naquad/data-sync/Sync/');

header('Content-Type: application/xml; charset=utf-8');
header('DAV: 1,2,3');
header('MS-Author-Via: DAV');
header('Allow: GET, PROPFIND, OPTIONS');

function h($str) {
    return htmlspecialchars(strval($str), encoding: 'UTF-8');
}

function respond(string $url, string $path) {
    $size = filesize($path);
    $mtime = gmdate('D, d M Y H:i:s \G\M\T', filemtime($path));
    $url = str_replace('%2F', '/', rawurlencode($url));
    $mime = mime_content_type($path) ?: 'application/octet-stream';
?>
    <d:response>
        <d:href><?= h($url) ?></d:href>
        <d:propstat>
            <d:prop>
                <d:displayname><?= h(basename($path)) ?></d:displayname>
                <d:getcontentlength><?= $size ?: 0 ?></d:getcontentlength>
                <d:getlastmodified ns0:dt="dateTime.rfc1123"><?= h($mtime) ?></d:getlastmodified>
                <?php if (is_dir($path)) { ?>
                <d:resourcetype><d:collection/></d:resourcetype>
                <d:getcontenttype>httpd/unix-directory</d:getcontenttype>
                <?php } else  { ?>
                <d:resourcetype/>
                <d:getcontenttype><?= h($mime) ?></d:getcontenttype>
                <?php } ?>
            </d:prop>
            <d:status>HTTP/1.1 200 OK</d:status>
        </d:propstat>
    </d:response>
<?php
}

function fail(string $msg, int $code) {
?>
<d:error xmlns:d="DAV:">
  <d:response>
    <d:href><?= h(parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH)) ?></d:href>
    <d:status>HTTP/1.1 <?= $code ?> <?= h($msg) ?></d:status>
  </d:response>
</d:error>
<?php
    exit;
}

echo '<?xml version="1.0" encoding="UTF-8" ?>', PHP_EOL;

if (empty($_GET['path'])) {
    fail('Bad request', 400);
}

$rurl = rtrim(BASE_URL, '/') . '/';
$rpath = rtrim(realpath(ROOT_PATH), '/') . '/';
$path = realpath($rpath . $_GET['path']);

if (!file_exists($path) || !is_dir($path) || !str_starts_with($path, $rpath)) {
    fail('Not Found', 404);
}

$url = $rurl . substr($path, strlen($rpath));
    
if ($_SERVER["REQUEST_METHOD"] == "OPTIONS") {
    exit;
}

if (
    $_SERVER["REQUEST_METHOD"] != "GET" &&
    $_SERVER["REQUEST_METHOD"] != "PROPFIND"
) {
    fail('Method Not Allowed', 405);
}

http_response_code(207); // Multi-Status

echo <<<EOF
<d:multistatus xmlns:d="DAV:" xmlns:ns0="urn:uuid:c2f41010-65b3-11d1-a29f-00aa00c14882/">\n
EOF;

respond($url, $path);

foreach (scandir($path) as $file) {
    if ($file == '.' || $file == '..') {
        continue;
    }

    $fpath = $path . '/' . $file;
    if (!is_link($fpath)) {
        continue;
    }

    $target = readlink($fpath);
    if (str_starts_with($target, '.')) {
        $target = $path . '/' . $target;
    }
    $target = realpath($target);

    if ($target === false || !str_starts_with($target, $rpath)) {
        continue;
    }

    $relative = substr($target, strlen($rpath));
    respond($rurl . $relative, $target);
}

echo '</d:multistatus>', PHP_EOL;