Using forwarded filesystems with Windows Remote Client (e.g. accessing //TSCLIENT/L via mstsc.exe) ?

Thu Jan 9 15:18:10 GMT 2025

On Wed, Jan 8, 2025 at 5:33 PM Roland Mainz <roland.mainz@nrubsig.org> wrote:
>> Hi!
>> ----
>> Does Cygwin 3.6 support filesystems which have been forwarded by the
> Windows Remote Client (mstsc.exe) ?
>> I tried to access such a forwarded dir, but $ ls -l # returned this:
> ---- snip ----
> $ bash -c 'cd //TSCLIENT/L && ls -l'
> ls: cannot read symbolic link 'newtestmachine_dir2': Invalid argument
> ls: cannot read symbolic link 'winserver2019_admindir2': Invalid argument
> total 665207504417527
> ?--xr--r-x 0 Unix_User+2 Unix_Group+1252
> 8589934592 Jan 1 1970 builds
> ?--xr--r-x 65535 Unix_User+0 Unix_Group+6539296
> 8589934592 Jan 1 1970 download
> ?--xr--r-x 65535 Unix_User+0 Unix_Group+6539296
> 8589934592 Jan 1 1970 gitbundles
> ?--xr--r-x 65535 Unix_User+0 Unix_Group+6539296
> 8589934592 Jan 1 1970 newtestmachine1
> l-----xr-x 13 Unix_User+6539088 Unix_Group+6539672
> 4294967295 Jan 1 1970 newtestmachine_dir2
> ?-ws-wS--t 65535 Unix_User+0 Unix_Group+6539296
> 4294967296000 Jan 1 1970 newtestmachine_dir3
> ?--xr--r-x 65535 Unix_User+0 Unix_Group+6539296
> 8589934592 Jan 1 1970 rde
> ?--xr--r-x 65535 Unix_User+0 Unix_Group+6539296
> 8589934592 Jan 1 1970 rde.zip
> ?-ws-wS--t 65535 Unix_User+0 Unix_Group+6539296
> 4294967296000 Mar 17 1970 te_install
> l-----x-wx 11 Unix_User+6539088 Unix_Group+6539672
> 4294967295 Jan 1 1970 winserver2019_admindir2
> ---- snip ----
>> Any idea what is going wrong in this case ?

Short update:
On the machine which got the forwarded filesystems I get this:
---- snip ----
$ nfs_ea '\??\UNC\TSCLIENT\T\test1' getnfs3attr
Querying extended attribute 'NfsV3Attributes' on file
'\??\UNC\TSCLIENT\T\test1':
ZwQueryEaFile('"') failed with 0xc0000002
---- snip ----
0xC0000002 == STATUS_NOT_IMPLEMENTED
The Windows NFSv3 and NFSv4.1/NFSv.2 drivers implement support for
"NfsV3Attributes", so it seems filesystem forwarding in RDP does not
support EAs (=extended attributes).
Powershell itself can handle files&&cd etc., it seems only
applications which rely on "NfsV3Attributes" are affected...
... maybe in Cygwin there are places where the return code for
|nfs_fetch_fattr3()| isn't checked ?

----
Bye,
Roland
-- 
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