Nextcloud 15: no PUT Range support

[abishai]

It looks like SabreDav capabilities are not detected (or broken). I collected a trace, however I found nothing suspicious. Is it working for you ?

[miquels]

I made a demo account on nextcloud.com, and did a webdav PROPFIND request:

$ curl -i --user "admin:admin" -X OPTIONS https://demo.nextcloud.com/ae8oobah/remote.php/dav/files/admin/
HTTP/1.1 200 OK
Date: Tue, 19 Mar 2019 13:00:23 GMT
Server: Apache
Allow: OPTIONS, GET, HEAD, DELETE, PROPFIND, PUT, PROPPATCH, COPY, MOVE, REPORT
DAV: 1, 3, extended-mkcol, access-control, calendarserver-principal-property-search, nc-calendar-search, nc-enable-birthday-calendar
MS-Author-Via: DAV

The SabreDav PATCH specification says that sabredav-partialupdate needs to be advertised in the DAV: header. It isn't ... so, file a bug with nextcloud?

[abishai]

Good question! I missed that.
I'll take a look where it returns capabilities.

[abishai]

Updated: Issue #439. Lots of updates in PATCH support. The Sabre_DAV_PartialUpdate_IFile interface is now deprecated and will be removed in a future version.

Looks like Nextcloud uses PATCH method to do partial updates.

[miquels]

Well, yes, that is the SabreDav standard, to use PATCH. In a specific way, see http://sabre.io/dav/http-patch/. However, if a server implements this, it must indicate that by putting sabredav-partialupdate in the DAV: header reply to an OPTION request.

[miquels]

If there is no followup to this issue I will close it tomorrow.

[abishai]

Yep, it is not activated on Nextcloud side.

[miquels]

Let's keep this issue open since the Nextcloud issue is also still open.

[muety]

Would it be an option to add a flag that instruct webdavfs to "forcefully" assume the required feature to be present, even if not advertised? webdavfs worked properly with Nextcloud, it would make a perfect modern alternative to the old davfs2 for me.

EDIT: Btw., maybe someone here, who is familiar with the inner workings of WebDAV, has an idea related to this problem: https://help.nextcloud.com/t/webdav-extremely-slow-on-linux-using-davfs2-mount/123811 ?

[sambler]

I don't think it is worth opening a new issue, as I am getting the same error with a cpanel webdav setup.

I can add the rwdirops option and skip the "no PUTS range" error, I can then create and delete a dir, but creating or editing a file fails.

I am using FreeBSD 13 and build webdavfs using the newest master revision

% curl -i -X OPTIONS https://XXXX.com:2078
HTTP/1.1 200 OK
Date: Tue, 18 Jan 2022 06:43:12 GMT
Server: cPanel
Persistent-Auth: false
Host: XXXX.com:2078
Cache-Control: no-cache, no-store, must-revalidate, private
Connection: Keep-Alive
Vary: Accept-Encoding
Allow: POST, UNLOCK, HEAD, PUT, MOVE, DELETE, PROPPATCH, LOCK, COPY, MKCOL, GET, PROPFIND, OPTIONS
Content-Length: 0
Content-Type: text/plain
Expires: Fri, 01 Jan 1990 00:00:00 GMT
DAV: 1, 2
Keep-Alive: timeout=15, max=96
MS-Author-Via: DAV

[Evidlo]

Looking through the source code, you can force this to be enabled with the option -o rwdirops option.

webdavfs/main.go

Lines 263 to 266 in 117d633

	if !dav.CanPutRange() && !mountOpts.ReadOnly && !mountOpts.ReadWriteDirOps {
	fmt.Fprintf(os.Stderr, "%s: no PUT Range support, mounting read-only\n", url)
	mountOpts.ReadOnly = true
	}

[miquels]

I've added a mount option "sabredav_partialupdate" to force using the sabredav partialupdate protocol even when the remote server doesn't advertise support for it. See 5751a44