Merge pull request #23 from Terranom674/fix/0971-webdav-public-ip

0.9.7.1: WebDAV über öffentliche Ziel-IP
2026-09-19 14:04:34 +00:00 · 2026-08-19 20:43:19 +02:00
parent ad39b9f0d2 5c62dbd9be
commit 2c302b356d
9 changed files with 428 additions and 19 deletions
--- a/include/nc_connector_wizard_webdav_flow.inc.php
+++ b/include/nc_connector_wizard_webdav_flow.inc.php
@@ -28,7 +28,7 @@ function bratonien_tools_nc_wizard_scan_webdav_first()
  {
    try
    {
-      $response = bratonien_tools_nc_wizard_http($candidate_url.'/status.php');
+      $response = bratonien_tools_nc_transport_http($candidate_url.'/status.php');
      if ($response['status'] < 200 || $response['status'] >= 300) continue;
      $candidate_status = json_decode($response['body'], true);
      if (!is_array($candidate_status) || empty($candidate_status['installed'])) continue;
@@ -44,7 +44,7 @@ function bratonien_tools_nc_wizard_scan_webdav_first()
    throw new RuntimeException('Unter dieser Adresse konnte keine Nextcloud erreicht werden. HTTP und HTTPS wurden automatisch geprüft.');
  }

-  $user_response = bratonien_tools_nc_wizard_http(
+  $user_response = bratonien_tools_nc_transport_http(
    $base_url.'/ocs/v2.php/cloud/user?format=json',
    $username,
    $password,
@@ -104,7 +104,7 @@ function bratonien_tools_nc_wizard_scan_webdav_first()
    'api_error'=>'',
  ));

-  bratonien_tools_nc_wizard_refresh_directory_state($state, '');
+  bratonien_tools_nc_transport_refresh_directory_state($state, '');
  bratonien_tools_nc_wizard_store($state);

  return array('message'=>'Nextcloud und WebDAV wurden bestätigt. Jetzt können die Verzeichnisse des angemeldeten Benutzers ausgewählt werden.');
--- a/include/nc_transport.inc.php
+++ b/include/nc_transport.inc.php
@@ -0,0 +1,340 @@
+<?php
+
+function bratonien_tools_nc_transport_host($url)
+{
+  $host = trim((string)parse_url((string)$url, PHP_URL_HOST));
+  if ($host === '') throw new RuntimeException('Die Nextcloud-Adresse enthält keinen gültigen Hostnamen oder keine IP-Adresse.');
+  return trim($host, '[]');
+}
+
+function bratonien_tools_nc_transport_scheme($url)
+{
+  $scheme = strtolower(trim((string)parse_url((string)$url, PHP_URL_SCHEME)));
+  if (!in_array($scheme, array('http','https'), true)) throw new RuntimeException('Nextcloud muss per HTTP oder HTTPS angesprochen werden.');
+  return $scheme;
+}
+
+function bratonien_tools_nc_transport_is_ip($host)
+{
+  return filter_var(trim((string)$host, '[]'), FILTER_VALIDATE_IP) !== false;
+}
+
+function bratonien_tools_nc_transport_public_ip($host)
+{
+  static $cache = array();
+
+  $host = strtolower(trim((string)$host, '[]'));
+  if ($host === '') throw new RuntimeException('Für die Nextcloud-Verbindung fehlt der Hostname.');
+  if (bratonien_tools_nc_transport_is_ip($host)) return $host;
+  if (isset($cache[$host])) return $cache[$host];
+  if (!function_exists('curl_init')) throw new RuntimeException('Der öffentliche DNS-Abgleich benötigt PHP-cURL.');
+
+  $providers = array(
+    array('host'=>'dns.google', 'ips'=>array('8.8.8.8','8.8.4.4'), 'url'=>'https://dns.google/resolve?name='.rawurlencode($host).'&type=A'),
+    array('host'=>'cloudflare-dns.com', 'ips'=>array('1.1.1.1','1.0.0.1'), 'url'=>'https://cloudflare-dns.com/dns-query?name='.rawurlencode($host).'&type=A'),
+  );
+
+  foreach ($providers as $provider)
+  {
+    foreach ($provider['ips'] as $resolver_ip)
+    {
+      $ch = curl_init($provider['url']);
+      $options = array(
+        CURLOPT_RETURNTRANSFER=>true,
+        CURLOPT_FOLLOWLOCATION=>false,
+        CURLOPT_CONNECTTIMEOUT=>5,
+        CURLOPT_TIMEOUT=>10,
+        CURLOPT_HTTPHEADER=>array('Accept: application/dns-json'),
+        CURLOPT_USERAGENT=>'Bratonien-Tools-DNS/0.9.7.1',
+      );
+      if (defined('CURLOPT_RESOLVE'))
+      {
+        $options[CURLOPT_RESOLVE] = array($provider['host'].':443:'.$resolver_ip);
+      }
+      curl_setopt_array($ch, $options);
+      $body = curl_exec($ch);
+      $errno = curl_errno($ch);
+      $status = (int)curl_getinfo($ch, CURLINFO_HTTP_CODE);
+      curl_close($ch);
+      if ($body === false || $errno !== 0 || $status < 200 || $status >= 300) continue;
+
+      $decoded = json_decode((string)$body, true);
+      if (!is_array($decoded) || !isset($decoded['Answer']) || !is_array($decoded['Answer'])) continue;
+      foreach ($decoded['Answer'] as $answer)
+      {
+        if ((int)($answer['type'] ?? 0) !== 1) continue;
+        $ip = trim((string)($answer['data'] ?? ''));
+        if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4 | FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE) === false) continue;
+        return $cache[$host] = $ip;
+      }
+    }
+  }
+
+  throw new RuntimeException('Für '.$host.' konnte keine öffentliche IPv4-Adresse ermittelt werden.');
+}
+
+function bratonien_tools_nc_transport_resolve_entry($url)
+{
+  $scheme = bratonien_tools_nc_transport_scheme($url);
+  $host = bratonien_tools_nc_transport_host($url);
+  if (bratonien_tools_nc_transport_is_ip($host)) return null;
+
+  $port = (int)parse_url((string)$url, PHP_URL_PORT);
+  if ($port < 1) $port = $scheme === 'https' ? 443 : 80;
+  $ip = bratonien_tools_nc_transport_public_ip($host);
+  return $host.':'.$port.':'.$ip;
+}
+
+function bratonien_tools_nc_transport_apply_curl(array &$options, $url)
+{
+  $entry = bratonien_tools_nc_transport_resolve_entry($url);
+  if ($entry !== null)
+  {
+    if (!defined('CURLOPT_RESOLVE')) throw new RuntimeException('Diese cURL-Version unterstützt keine direkte Host-zu-IP-Zuordnung.');
+    $options[CURLOPT_RESOLVE] = array($entry);
+  }
+}
+
+function bratonien_tools_nc_transport_http($url, $username = '', $password = '', array $headers = array())
+{
+  if (!function_exists('curl_init')) throw new RuntimeException('Der Server kann Nextcloud derzeit nicht per HTTP prüfen.');
+
+  $ch = curl_init($url);
+  $options = array(
+    CURLOPT_RETURNTRANSFER=>true,
+    CURLOPT_FOLLOWLOCATION=>true,
+    CURLOPT_MAXREDIRS=>3,
+    CURLOPT_CONNECTTIMEOUT=>8,
+    CURLOPT_TIMEOUT=>15,
+    CURLOPT_HTTPHEADER=>array_merge(array('Accept: application/json'), $headers),
+    CURLOPT_USERAGENT=>'Bratonien-Tools-NC-Wizard/0.9.7.1',
+  );
+  bratonien_tools_nc_transport_apply_curl($options, $url);
+
+  if ($username !== '')
+  {
+    $options[CURLOPT_HTTPAUTH] = CURLAUTH_BASIC;
+    $options[CURLOPT_USERPWD] = $username.':'.$password;
+  }
+
+  curl_setopt_array($ch, $options);
+  $body = curl_exec($ch);
+  $errno = curl_errno($ch);
+  $error = curl_error($ch);
+  $status = (int)curl_getinfo($ch, CURLINFO_HTTP_CODE);
+  curl_close($ch);
+
+  if ($body === false || $errno !== 0)
+  {
+    throw new RuntimeException('Verbindung fehlgeschlagen'.($error !== '' ? ': '.$error : '.'));
+  }
+
+  return array('status'=>$status, 'body'=>(string)$body);
+}
+
+function bratonien_tools_nc_transport_webdav_list(array $state, $path = '')
+{
+  if (empty($state['scan_ok']) || trim((string)$state['base_url']) === '' || trim((string)$state['username']) === '' || (string)$state['_password'] === '')
+  {
+    throw new RuntimeException('Die Nextcloud-Sitzung des Assistenten ist nicht vollständig.');
+  }
+  if (!function_exists('curl_init')) throw new RuntimeException('cURL ist für die Verzeichnisauswahl nicht verfügbar.');
+
+  $path = trim((string)$path, '/');
+  if ($path !== '' && preg_match('#(^|/)\.\.(/|$)#', $path)) throw new RuntimeException('Ungültiger Verzeichnispfad.');
+
+  $segments = $path === '' ? array() : array_map('rawurlencode', explode('/', $path));
+  $user = rawurlencode((string)$state['username']);
+  $url = rtrim((string)$state['base_url'], '/').'/remote.php/dav/files/'.$user.'/'.implode('/', $segments);
+  if (substr($url, -1) !== '/') $url .= '/';
+
+  $body = '<?xml version="1.0"?><d:propfind xmlns:d="DAV:" xmlns:oc="http://owncloud.org/ns"><d:prop><d:resourcetype/><d:displayname/><oc:fileid/></d:prop></d:propfind>';
+  $ch = curl_init($url);
+  $options = array(
+    CURLOPT_RETURNTRANSFER=>true,
+    CURLOPT_CUSTOMREQUEST=>'PROPFIND',
+    CURLOPT_POSTFIELDS=>$body,
+    CURLOPT_HTTPHEADER=>array('Depth: 1','Content-Type: application/xml; charset=utf-8'),
+    CURLOPT_HTTPAUTH=>CURLAUTH_BASIC,
+    CURLOPT_USERPWD=>(string)$state['username'].':'.(string)$state['_password'],
+    CURLOPT_CONNECTTIMEOUT=>8,
+    CURLOPT_TIMEOUT=>20,
+  );
+  bratonien_tools_nc_transport_apply_curl($options, $url);
+  curl_setopt_array($ch, $options);
+  $response = curl_exec($ch);
+  $errno = curl_errno($ch);
+  $error = curl_error($ch);
+  $status = (int)curl_getinfo($ch, CURLINFO_HTTP_CODE);
+  curl_close($ch);
+
+  if ($response === false || $errno !== 0) throw new RuntimeException('Nextcloud-Verzeichnisse konnten nicht geladen werden'.($error !== '' ? ': '.$error : '.'));
+  if ($status === 401 || $status === 403) throw new RuntimeException('Nextcloud hat den Zugriff auf dieses Verzeichnis abgelehnt.');
+  if ($status !== 207) throw new RuntimeException('Nextcloud-Verzeichnisabfrage antwortete mit HTTP '.$status.'.');
+
+  libxml_use_internal_errors(true);
+  $xml = simplexml_load_string((string)$response);
+  if ($xml === false) throw new RuntimeException('Nextcloud hat eine ungültige WebDAV-Antwort geliefert.');
+  $xml->registerXPathNamespace('d', 'DAV:');
+  $xml->registerXPathNamespace('oc', 'http://owncloud.org/ns');
+
+  $children = array();
+  $fileids = array();
+  $current_fileid = 0;
+  $base_path = (string)parse_url($url, PHP_URL_PATH);
+
+  foreach ($xml->xpath('//d:response') as $item)
+  {
+    $item->registerXPathNamespace('d', 'DAV:');
+    $item->registerXPathNamespace('oc', 'http://owncloud.org/ns');
+    $hrefs = $item->xpath('d:href');
+    $collections = $item->xpath('d:propstat/d:prop/d:resourcetype/d:collection');
+    $ids = $item->xpath('d:propstat/d:prop/oc:fileid');
+    if (!$hrefs || !$collections || !$ids) continue;
+
+    $fileid = (int)trim((string)$ids[0]);
+    if ($fileid < 1) continue;
+    $href = rawurldecode((string)$hrefs[0]);
+    $href_path = (string)parse_url($href, PHP_URL_PATH);
+
+    if (rtrim($href_path, '/') === rtrim($base_path, '/'))
+    {
+      $current_fileid = $fileid;
+      continue;
+    }
+
+    $name = basename(rtrim($href_path, '/'));
+    if ($name === '') continue;
+    $child_path = $path === '' ? $name : $path.'/'.$name;
+    $children[$child_path] = $name;
+    $fileids[$child_path] = $fileid;
+  }
+  natcasesort($children);
+
+  if ($current_fileid < 1) throw new RuntimeException('Nextcloud hat für das aktuelle Verzeichnis keine eindeutige Datei-ID geliefert.');
+
+  $parent = '';
+  if ($path !== '')
+  {
+    $parts = explode('/', $path);
+    array_pop($parts);
+    $parent = implode('/', $parts);
+  }
+
+  return array(
+    'current'=>$path,
+    'parent'=>$parent,
+    'children'=>$children,
+    'current_fileid'=>$current_fileid,
+    'fileids'=>$fileids,
+  );
+}
+
+function bratonien_tools_nc_transport_refresh_directory_state(array &$state, $path = null)
+{
+  if ($path === null) $path = (string)($state['directory_path'] ?? '');
+  $listing = bratonien_tools_nc_transport_webdav_list($state, $path);
+  $state['directory_path'] = (string)$listing['current'];
+  $state['directory_parent'] = (string)$listing['parent'];
+  $state['directory_children'] = (array)$listing['children'];
+  $state['directory_current_fileid'] = (int)$listing['current_fileid'];
+  $state['directory_fileids'] = (array)$listing['fileids'];
+  if (!isset($state['directory_selected']) || !is_array($state['directory_selected'])) $state['directory_selected'] = array();
+  if (!isset($state['directory_selected_fileids']) || !is_array($state['directory_selected_fileids'])) $state['directory_selected_fileids'] = array();
+}
+
+function bratonien_tools_nc_transport_wizard_directory_browse()
+{
+  $state = bratonien_tools_nc_wizard_state();
+  if ((int)$state['step'] !== 2 || (string)$state['technical_stage'] !== 'mounts' || empty($state['directory_selection_ready'])) throw new RuntimeException('Die Verzeichnisauswahl ist in diesem Fenster nicht verfügbar.');
+  $path = trim((string)($_POST['nc_wizard_directory_path'] ?? ''), '/');
+  bratonien_tools_nc_transport_refresh_directory_state($state, $path);
+  bratonien_tools_nc_wizard_store($state);
+  return array('message'=>'Verzeichnis geöffnet.');
+}
+
+function bratonien_tools_nc_transport_edit_start()
+{
+  $id = (int)($_POST['connection_id'] ?? 0);
+  $connection = bratonien_tools_nc_connector_connection($id, true);
+  if (!$connection) throw new RuntimeException('Connector-Verbindung wurde nicht gefunden.');
+
+  $config = isset($connection['config']) && is_array($connection['config']) ? $connection['config'] : array();
+  $is_webdav = (string)$connection['adapter'] === 'remote'
+    && (string)($config['source_mode'] ?? '') === 'webdav-placeholder';
+  if (!$is_webdav) return bratonien_tools_nc_connector_edit_start();
+
+  $credentials = bratonien_tools_nc_connector_scoped_secret($connection);
+  $base_url = trim((string)($config['nextcloud_url'] ?? ''));
+  $username = trim((string)($credentials['nextcloud_user'] ?? ''));
+  if ($username === '') $username = trim((string)($config['nextcloud_access_user'] ?? $config['access_user'] ?? ''));
+  $password = (string)($credentials['nextcloud_password'] ?? '');
+
+  $roots = isset($config['roots']) && is_array($config['roots']) ? array_values($config['roots']) : array();
+  $selected = array();
+  $selected_ids = array();
+  foreach ($roots as $root)
+  {
+    $path = trim((string)($root['webdav_path'] ?? ''), '/');
+    $fileid = (int)($root['fileid'] ?? 0);
+    if ($fileid < 1) continue;
+    $selected[] = $path;
+    $selected_ids[$path] = $fileid;
+  }
+
+  $state = bratonien_tools_nc_wizard_state();
+  $state = array_merge($state, array(
+    'editing_connection_id'=>$id,
+    'editing_adapter'=>(string)$connection['adapter'],
+    'editing_mode'=>'update',
+    'connection_name'=>(string)$connection['name'],
+    'host_input'=>$base_url,
+    'base_url'=>$base_url,
+    'username'=>$username,
+    '_password'=>$password,
+    '_fallback_user'=>(string)($credentials['piwigo_user'] ?? ''),
+    '_fallback_password'=>(string)($credentials['piwigo_password'] ?? ''),
+    '_api_key_id'=>(string)($credentials['api_key_id'] ?? ''),
+    '_api_key_secret'=>(string)($credentials['api_key_secret'] ?? ''),
+    'api_status'=>trim((string)($credentials['api_key_id'] ?? '')) !== '' && trim((string)($credentials['api_key_secret'] ?? '')) !== '' ? 'ok' : 'pending',
+    'roots'=>$roots,
+    'directory_selected'=>$selected,
+    'directory_selected_fileids'=>$selected_ids,
+    'source_mode'=>'webdav-placeholder',
+    'transport'=>'webdav',
+  ));
+
+  if ($base_url !== '' && $username !== '' && $password !== '')
+  {
+    $state['step'] = 2;
+    $state['scan_ok'] = true;
+    $state['technical_stage'] = 'mounts';
+    $state['technical_source'] = 'WebDAV';
+    $state['technical_error'] = '';
+    $state['technical_complete'] = false;
+    $state['directory_selection_ready'] = true;
+    $state['directory_path'] = '';
+    $state['directory_parent'] = '';
+    $state['directory_children'] = array();
+    $state['directory_current_fileid'] = 0;
+
+    try
+    {
+      bratonien_tools_nc_transport_refresh_directory_state($state, '');
+    }
+    catch (Throwable $e)
+    {
+      $state['step'] = 1;
+      $state['scan_ok'] = false;
+      $state['technical_error'] = $e->getMessage();
+    }
+  }
+  else
+  {
+    $state['step'] = 1;
+    $state['scan_ok'] = false;
+  }
+
+  bratonien_tools_nc_wizard_store($state);
+  return array('message'=>'Verbindung #'.$id.' wurde zum Bearbeiten geöffnet.');
+}
--- a/include/tool_registry.inc.php
+++ b/include/tool_registry.inc.php
@@ -6,7 +6,7 @@ if (!defined('PHPWG_ROOT_PATH'))

 if (isset($GLOBALS['template']) && is_object($GLOBALS['template']) && method_exists($GLOBALS['template'], 'func_combine_script'))
 {
-  $script_version = function_exists('bratonien_tools_current_version') ? bratonien_tools_current_version() : '0.9.6.30';
+  $script_version = function_exists('bratonien_tools_current_version') ? bratonien_tools_current_version() : '0.9.7.1';
  $GLOBALS['template']->func_combine_script(array(
    'id'=>'bratonien_nc_connector_edit_v2',
    'path'=>BRATONIEN_TOOLS_PATH.'js/nc_connector_edit_v2.js',
@@ -41,6 +41,7 @@ require_once(BRATONIEN_TOOLS_PATH . 'include/nc_connector_delete_safe.inc.php');
 require_once(BRATONIEN_TOOLS_PATH . 'include/nc_connector_webdav.inc.php');
 require_once(BRATONIEN_TOOLS_PATH . 'include/nc_connector_wizard_webdav_flow.inc.php');
 require_once(BRATONIEN_TOOLS_PATH . 'include/nc_connector_edit.inc.php');
+require_once(BRATONIEN_TOOLS_PATH . 'include/nc_transport.inc.php');
 require_once(BRATONIEN_TOOLS_PATH . 'include/nc_connector_scheduler.inc.php');
 require_once(BRATONIEN_TOOLS_PATH . 'include/nc_connector_system.inc.php');

@@ -74,7 +75,7 @@ function bratonien_tools_get_tools()
    'album_share_regenerate_link' => array('handler' => 'bratonien_tools_regenerate_album_share_link'),
    'album_share_revoke' => array('handler' => 'bratonien_tools_revoke_album_share'),
    'nc_connector_create_webdav_parallel' => array('handler' => 'bratonien_tools_nc_connector_create_webdav_placeholder_from_wizard'),
-    'nc_connector_edit_start' => array('handler' => 'bratonien_tools_nc_connector_edit_start'),
+    'nc_connector_edit_start' => array('handler' => 'bratonien_tools_nc_transport_edit_start'),
    'nc_connector_update_local' => array('handler' => 'bratonien_tools_nc_connector_update_local_friendly'),
    'nc_connector_delete' => array('handler' => 'bratonien_tools_nc_connector_delete_safe'),
    'nc_connector_update_name' => array('handler' => 'bratonien_tools_nc_connector_update_name'),
@@ -82,7 +83,7 @@ function bratonien_tools_get_tools()
    'nc_connector_run_now' => array('handler' => 'bratonien_tools_nc_connector_run_now'),
    'nc_connector_wizard_scan' => array('handler' => 'bratonien_tools_nc_wizard_scan_webdav_first'),
    'nc_connector_wizard_save_technical' => array('handler' => 'bratonien_tools_nc_wizard_save_technical_flow'),
-    'nc_connector_wizard_directory_browse' => array('handler' => 'bratonien_tools_nc_wizard_directory_browse'),
+    'nc_connector_wizard_directory_browse' => array('handler' => 'bratonien_tools_nc_transport_wizard_directory_browse'),
    'nc_connector_wizard_directory_add' => array('handler' => 'bratonien_tools_nc_wizard_directory_add'),
    'nc_connector_wizard_directory_remove' => array('handler' => 'bratonien_tools_nc_wizard_directory_remove'),
    'nc_connector_wizard_save_mounts' => array('handler' => 'bratonien_tools_nc_wizard_save_sources_dispatch'),
--- a/main.inc.php
+++ b/main.inc.php
@@ -1,7 +1,7 @@
 <?php
 /*
 Plugin Name: Bratonien Tools
-Version: 0.9.6.30
+Version: 0.9.7.1
 Description: Erweiterbare Administrationswerkzeuge fuer die Bratonien-Piwigo-Installation.
 Plugin URI: https://github.com/Terranom674/Piwigo_Bratonien_Tools
 Author: Bratonien
--- a/runtime/lib/build_webdav_placeholder_source.py
+++ b/runtime/lib/build_webdav_placeholder_source.py
@@ -14,6 +14,7 @@ import getpass
 import json
 import os
 import shutil
+import socket
 import ssl
 import sys
 import tempfile
@@ -21,6 +22,7 @@ import urllib.error
 import urllib.parse
 import urllib.request
 import xml.etree.ElementTree as ET
+from contextlib import contextmanager
 from pathlib import Path, PurePosixPath

 DAV = "DAV:"
@@ -52,9 +54,37 @@ def safe_local_name(name: str) -> str:
    return name


+@contextmanager
+def pinned_resolution(host: str, ip: str):
+    host = host.strip("[]").lower()
+    ip = ip.strip("[]")
+    if not host or not ip or host == ip:
+        yield
+        return
+
+    original = socket.getaddrinfo
+
+    def resolve(name, port, family=0, type=0, proto=0, flags=0):
+        normalized = str(name).strip("[]").lower()
+        if normalized == host:
+            return original(ip, port, family, type, proto, flags)
+        return original(name, port, family, type, proto, flags)
+
+    socket.getaddrinfo = resolve
+    try:
+        yield
+    finally:
+        socket.getaddrinfo = original
+
+
 class WebDavClient:
-    def __init__(self, base_url: str, user: str, password: str, timeout: int = 30) -> None:
+    def __init__(self, base_url: str, user: str, password: str, timeout: int = 30, connect_ip: str = "") -> None:
        self.base_url = base_url.rstrip("/")
+        parsed = urllib.parse.urlparse(self.base_url)
+        if parsed.scheme not in {"http", "https"} or not parsed.hostname:
+            fail("Nextcloud base URL must use HTTP or HTTPS and contain a host")
+        self.host = parsed.hostname.strip("[]")
+        self.connect_ip = connect_ip.strip("[]") or self.host
        self.user = user
        self.password = password
        self.timeout = timeout
@@ -84,9 +114,10 @@ class WebDavClient:
        request.add_header("Depth", "1")
        request.add_header("Content-Type", "application/xml; charset=utf-8")
        try:
-            with urllib.request.urlopen(request, timeout=self.timeout, context=self.context) as response:
-                status = response.status
-                payload = response.read()
+            with pinned_resolution(self.host, self.connect_ip):
+                with urllib.request.urlopen(request, timeout=self.timeout, context=self.context) as response:
+                    status = response.status
+                    payload = response.read()
        except urllib.error.HTTPError as error:
            if error.code in {401, 403}:
                fail("Nextcloud rejected the WebDAV credentials or directory access")
@@ -96,14 +127,14 @@ class WebDavClient:
        if status != 207:
            fail(f"Nextcloud PROPFIND returned HTTP {status}")

+        base_path = urllib.parse.unquote(urllib.parse.urlparse(url).path).rstrip("/")
+        current: dict[str, object] | None = None
+        children: list[dict[str, object]] = []
        try:
            root = ET.fromstring(payload)
        except ET.ParseError as error:
            raise RuntimeError("Nextcloud returned invalid WebDAV XML") from error

-        base_path = urllib.parse.unquote(urllib.parse.urlparse(url).path).rstrip("/")
-        current: dict[str, object] | None = None
-        children: list[dict[str, object]] = []
        for response in root.findall(f"{{{DAV}}}response"):
            href = response.findtext(f"{{{DAV}}}href", default="")
            href_path = urllib.parse.unquote(urllib.parse.urlparse(href).path).rstrip("/")
@@ -213,6 +244,7 @@ def atomic_text(path: Path, text: str) -> None:
 def main() -> int:
    parser = argparse.ArgumentParser()
    parser.add_argument("--base-url", required=True)
+    parser.add_argument("--connect-ip", default="", help="IP address used for the TCP connection while preserving the URL host for HTTP Host and TLS SNI")
    parser.add_argument("--user", required=True)
    parser.add_argument("--password-file", type=Path)
    parser.add_argument("--root", action="append", required=True, help="WebDAV path relative to the authenticated user's files root")
@@ -241,7 +273,7 @@ def main() -> int:
            shutil.rmtree(staging)
        staging.mkdir(parents=True)

-        client = WebDavClient(args.base_url, args.user, password, max(1, args.timeout))
+        client = WebDavClient(args.base_url, args.user, password, max(1, args.timeout), args.connect_ip)
        mapping: dict[str, dict[str, object]] = {}
        manifest: list[str] = []
        total_files = total_folders = total_skipped = 0
@@ -303,6 +335,7 @@ def main() -> int:
        atomic_json(args.mapping, {
            "version": 1,
            "base_url": args.base_url.rstrip("/"),
+            "connect_ip": client.connect_ip,
            "user": args.user,
            "files": final_mapping,
        })
@@ -311,6 +344,7 @@ def main() -> int:
            "files": total_files,
            "folders": total_folders,
            "skipped": total_skipped,
+            "connect_ip": client.connect_ip,
            "source_dir": str(source_dir),
            "manifest": str(args.manifest),
            "mapping": str(args.mapping),
--- a/runtime/lib/precache-webdav-previews.php
+++ b/runtime/lib/precache-webdav-previews.php
@@ -6,6 +6,8 @@ if (PHP_SAPI !== 'cli')
  exit(1);
 }

+require_once(dirname(__DIR__, 2).'/include/nc_transport.inc.php');
+
 const BRATONIEN_WEBDAV_PREVIEW_VERSION = 2;
 const BRATONIEN_WEBDAV_PREVIEW_MAX_EDGE = 4096;
 const BRATONIEN_WEBDAV_PREVIEW_JPEG_QUALITY = 88;
@@ -24,7 +26,7 @@ function quote_webdav_path($path)
 function fetch_remote_blob($url, $user, $password)
 {
  $ch = curl_init($url);
-  curl_setopt_array($ch, array(
+  $options = array(
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_FOLLOWLOCATION => false,
    CURLOPT_CONNECTTIMEOUT => 10,
@@ -32,8 +34,10 @@ function fetch_remote_blob($url, $user, $password)
    CURLOPT_HTTPAUTH => CURLAUTH_BASIC,
    CURLOPT_USERPWD => $user.':'.$password,
    CURLOPT_FAILONERROR => false,
-    CURLOPT_USERAGENT => 'Bratonien-Tools-WebDAV-Precache/0.9.6.1',
-  ));
+    CURLOPT_USERAGENT => 'Bratonien-Tools-WebDAV-Precache/0.9.7.1',
+  );
+  bratonien_tools_nc_transport_apply_curl($options, $url);
+  curl_setopt_array($ch, $options);
  $body = curl_exec($ch);
  $errno = curl_errno($ch);
  $error = curl_error($ch);
--- a/runtime/lib/resolve-nextcloud-target.php
+++ b/runtime/lib/resolve-nextcloud-target.php
@@ -0,0 +1,24 @@
+#!/usr/bin/env php
+<?php
+if (PHP_SAPI !== 'cli')
+{
+  fwrite(STDERR, "CLI only\n");
+  exit(1);
+}
+
+require_once(dirname(__DIR__, 2).'/include/nc_transport.inc.php');
+
+try
+{
+  if ($argc !== 2) throw new RuntimeException('Aufruf: resolve-nextcloud-target.php <nextcloud-url>');
+  $url = rtrim(trim((string)$argv[1]), '/');
+  bratonien_tools_nc_transport_scheme($url);
+  $host = bratonien_tools_nc_transport_host($url);
+  echo bratonien_tools_nc_transport_public_ip($host)."\n";
+  exit(0);
+}
+catch (Throwable $e)
+{
+  fwrite(STDERR, $e->getMessage()."\n");
+  exit(1);
+}
--- a/runtime/sync-webdav.sh
+++ b/runtime/sync-webdav.sh
@@ -75,8 +75,12 @@ done < "$WEBDAV_ROOTS_FILE"

 [[ ${#ROOT_ARGS[@]} -gt 0 ]] || { write_status error "Keine WebDAV-Wurzeln konfiguriert"; exit 1; }

+WEBDAV_CONNECT_IP="$(php "$SCRIPT_DIR/lib/resolve-nextcloud-target.php" "$WEBDAV_BASE_URL")"
+[[ -n "$WEBDAV_CONNECT_IP" ]] || { write_status error "Nextcloud-Zieladresse konnte nicht ermittelt werden"; exit 1; }
+
 python3 "$SCRIPT_DIR/lib/build_webdav_placeholder_source.py" \
    --base-url "$WEBDAV_BASE_URL" \
+    --connect-ip "$WEBDAV_CONNECT_IP" \
    --user "$WEBDAV_USER" \
    --password-file "$WEBDAV_PASSWORD_FILE" \
    "${ROOT_ARGS[@]}" \
--- a/webdav-image.php
+++ b/webdav-image.php
@@ -8,6 +8,7 @@ if (!defined('BRATONIEN_TOOLS_PATH'))
  define('BRATONIEN_TOOLS_PATH', PHPWG_ROOT_PATH.'plugins/'.BRATONIEN_TOOLS_ID.'/');
 }
 require_once(BRATONIEN_TOOLS_PATH.'include/webdav_image_runtime.inc.php');
+require_once(BRATONIEN_TOOLS_PATH.'include/nc_transport.inc.php');

 function bratonien_tools_webdav_image_abort($status, $message)
 {
@@ -120,7 +121,7 @@ $options = array(
  CURLOPT_USERPWD => $user.':'.$password,
  CURLOPT_RETURNTRANSFER => false,
  CURLOPT_FAILONERROR => false,
-  CURLOPT_USERAGENT => 'Bratonien-Tools-WebDAV-Image/0.9.6.1',
+  CURLOPT_USERAGENT => 'Bratonien-Tools-WebDAV-Image/0.9.7.1',
  CURLOPT_HEADERFUNCTION => function($ch, $line)
  {
    $length = strlen($line);
@@ -147,6 +148,7 @@ $options = array(
    return strlen($data);
  },
 );
+bratonien_tools_nc_transport_apply_curl($options, $url);
 if (!empty($_SERVER['HTTP_RANGE']))
 {
  $range = trim((string)$_SERVER['HTTP_RANGE']);