[Samba] smbclient: Renaming file on DFS root fails with NT_STATUS_OBJECT_PATH_NOT_FOUND

[Jeremy Allison]

On Tue, Oct 22, 2019 at 12:27:17PM +0200, Christoph Ziebuhr via samba wrote:
> If a file is stored directly on a DFS enabled share, renaming fails with
> NT_STATUS_OBJECT_PATH_NOT_FOUND.
> The usecase may sound unusual, but a customer is using NetApp ONTAP 9, which
> by default advertises DFS capabilities for all shares, and he cannot disable
> it for policy reasons.
> I can also reproduce the issue with smbd and Windows Server 2012 R2 (haven't
> checked with other versions).
> 
> IMHO it is caused by:
> - Not setting SMB2_HDR_FLAG_DFS when calling smb2cli_req_send() from
> smb2cli_set_info_send()
> - cli_resolve_path() returning a full dfs path for the destination, which is
> then passed to cli_rename() to be used in SMB2_FILE_RENAME_INFO
> 
> After some patching and testing, I came to this conclusion:
> 
> Setting SMB2_HDR_FLAG_DFS solves the issue for smbd, but not for Windows
> Server and not for NetApp.
> It seems that the file name in SMB2_FILE_RENAME_INFO must always be a
> non-dfs path and the header flag is ignored:
> - A windows client uses a non-dfs path, but sets the header flag
> - Linux kernel also uses a non-dfs path and doesn't set the header flag
> 
> This means, path handling for cli_rename() needs to be changed.
> IMHO there are two possibilities:
> - Extend cli_resolve_path() to be able to also return a non-dfs path
> - Strip server/share from fname_dst in cli_rename(), e.g. with
> parse_dfs_path() from smbd

Can you send a debug level 10 log from smbclient so I
can see the exact problem ?

Also, can you log a bug at bugzilla.samba.org so we
can track the fix for this ?

Thanks !

Jeremy.