[linux-cifs-client] CIFS and Windows 2003 Server shares

[Leonardo Chiquitto]

Hello,

I'm doing some tests with CIFS client 1.54, trying to discover what
changed with Windows 2003 server that is resulting in a different
behavior from previous Windows versions. In the end, the goal is
to understand whether this is something we can workaround / avoid
on the client side.

The test:
- the same share is mounted twice with different user names
- the server is not a domain controller or member server
- the server doesn't "know" the users
- "Everyone" and "Guest" have full permissions in the share

The following commands were used:

# mount -t cifs //192.168.8.1/Shared /mnt/a -o
  noacl,noperm,user=john,dir_mode=0700,domain=DOMAIN,rw
# mount -t cifs //192.168.8.1/Shared /mnt/b -o
  noacl,noperm,user=jeff,dir_mode=0700,domain=DOMAIN,rw

Results with Windows 2000 Server:

- Both mount points are accessible in the client:

client:/mnt # ls -la
total 8
drwxr-xr-x  4 root root 4096 Dec  9 19:14 .
drwxr-xr-x 31 root root 4096 Dec 15 11:40 ..
drwx------  1 root root    0 Dec 15  2008 a
drwx------  1 root root    0 Dec 15  2008 b

- "net session" output from server:

Computer               User name            Client Type       Opens Idle time
-------------------------------------------------------------------------------
\\192.168.8.1          JOHN                 Linux version 2.6     0 00:01:40
\\192.168.8.1          JEFF                 Linux version 2.6     0 00:01:40

* We can see that Windows 2000 Server keeps the user name provided
by the client.

Results with Windows 2003 Server:

- Just the mount point mounted last is accessible:

client:/mnt # ls -la
ls: cannot access a: Permission denied
total 8
drwxr-xr-x  4 root root 4096 Dec  9 19:14 .
drwxr-xr-x 31 root root 4096 Dec 15 11:40 ..
d?????????  ? ?    ?       ?            ? a
drwx------  1 root root    0 Dec 15  2008 b

- "net session" output from the server:

Computer               User name            Client Type       Opens Idle time
-------------------------------------------------------------------------------
192.168.8.1          GUEST                Linux version 2.6     0 000012

* We can see that just one session remains and the user name was mapped to
GUEST.

I suppose this is expected, but I really would like to understand what is
the underlying cause.

Thanks!
Leonardo