On Jul 19 17:26, Bill Zissimopoulos wrote:
> On 7/19/16, 2:41 AM, Corinna Vinschen wrote:
> 
> >
> >Let's just try how it looks like.  I applied the patch using
> >"nodomain+nobody" for now and uploaded a developer snapshot to
> >https://cygwin.com/snapshots/
> 
> Hi, Corinna:
> 
> Here is simple SSHFS output with the patched cygwin1.dll:
> 
>     billziss@windows:/cygdrive/y$ ls -l
>     total 12
>     -r--r--r-- 1 nodomain+nobody nodomain+nobody 15 Jun 23 23:57 Foo.txt
>     ---------- 1 nodomain+nobody nodomain+nobody 15 Jul 15 16:48
> HelloWorld.txt
>     d--------- 1 nodomain+nobody nodomain+nobody  0 Jul 15 16:49 opt
> 
> And here are the actual permissions reported to the OS (and Cygwin):
> 
>     billziss@windows:/cygdrive/y$ for f in *; do cacls $f /S; done
>     Y:\Foo.txt 
> "D:P(A;;0x1f0199;;;S-1-0-65534)(A;;FR;;;S-1-0-65534)(A;;FR;;;WD)"
> 
>     Y:\HelloWorld.txt
> "D:P(A;;0x1f0198;;;S-1-0-65534)(A;;0x120088;;;S-1-0-65534)(A;;0x120088;;;WD
> )"
> 
>     Y:\opt 
> "D:P(A;;0x1f0198;;;S-1-0-65534)(A;;0x120088;;;S-1-0-65534)(A;;0x120088;;;WD
> )"
> 
> You will note that nodomain+nobody is used for both user and group. Which
> my understanding is that it is legal in Windows. [I note however that
> Cygwin is able to distinguish between Unknown+User and Unknown+Group.]

There's a difference.  Unknown+User/Unknown+Group are just
unidirectional fakes for SIDs the Windows functions can't resolve at
all.  There's no way to convert the username "Unknown+User" back to a
valid SID since all unknown SIDs are subsumed under Unknown+User with
uid -1.

OTOH, "nodomain+nobody" has a valid SID, at least in our self-defined
realm.  So Cygwin gets the same S-1-0-65534 SID for both, user and
group.  Since it has the same SID, it's the same account.

For all practical purposes that should work out fine.  You know
what to do with the SID on your side, Cygwin knows what to do with
the SID on its side,

Windows... not so, but since it's the same SID it is the same account
from Windows' perspective as well.

We just might still want to change the name to "no+body".

What do others on this list think?  What sounds better?

 "nodomain+nobody" or "no+body"

?


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat