WebDAV or Web Distributed Authoring and Versioning is an extension to HTTP. This service implements a WebDAV interface to the ILIAS-Repository. Since ILIAS version 5.4, the sabreDAV library from sabre-io is used to handle the HTTP-Requests. This services implements functionality behind this requests.
Because of a special behaviour in the Windows Explorer, it sometimes fails to add a WebDAV connection with the error code "0x80070043 The Network Name Cannot Be Found".
To prevent this behaviour, add the following rewrite rules to a .htaccess file in your webroot or to the corresponding section of the configuration of your webserver:
RewriteCond %{HTTP_USER_AGENT} ^(DavClnt)$
RewriteCond %{REQUEST_METHOD} ^(OPTIONS)$
RewriteRule .* "-" [R=401,L]
To upload files, the WebDAV Client Finder on Mac uses chunked transfer encoding. Some webservers can't handle this way of uploading files and are serving ILIAS an empty files, which results in an empty file object on ILIAS. Due to a bug in apache, the configuration of Apache with PHP-FPM does not work with the Mac Finder. If you use WebDAV on your ILIAS installation, we recommend to either use Apache with mod_php or Nginx with PHP-FPM (> 1.3.8).
Sabre (the creator of the used WebDAV library) has following things to say to this issue:
Finder uses Transfer-Encoding: Chunked in PUT request bodies. This is a little used HTTP feature, and therefore not implemented in a bunch of webservers. The only server I've seen so far that handles this reasonably well is Apache + mod_php. Nginx and Lighttpd respond with 411 Length Required, which is completely ignored by Finder. This was seen on nginx 0.7.63. It was recently reported that a development release (1.3.8) no longer had this issue.
When using this with Apache + FastCGI PHP completely drops the request body, so it will seem as if the PUT request was succesful, but the file will end up empty.