Samba Connect problems

Rossi, Marc MarcR at crt.com
Fri Dec 19 23:22:02 GMT 1997


Thanks in advance for reading this slightly long post.  I checked the
comp.protocols.smb archives along with the web site for info and was
unsuccessful.  All help and information is greatly appreciated.

We are using Samba (1.9.17p3) for access to our Clearcase VOBS which are
stored on a UNIX box (I'm aware this is supposedly not supported, but it
has been working great up until these problems cropped up).  Since our
upgrade to NT 4.0, we have seen problems where clients are unable to
access their Samba shares after a period of inactivity.  All clients are
accessing the shares using UNC only.  If they access a share and perform
some action (usually a checkout/checkin), the smbd prints out the
message saying the client has connected and all is fine.  After this
connection times out and the smbd prints out the message saying the
client disconnected, the client no longer is able to access the share,
with all attempts resulting in a message saying that the password is
invalid (The server prints out the message "Invalid guest account,
portbyron???", where the name "portbyron" is actually the hostname of
the client).  I am aware that this may not be a Samba problem, but could
lie in the MVFS (Clearcase) file system driver, or even in NT itself (we
are running 4.0 SP3).  What I am looking for is either a fix for Samba
(if it is indeed a Samba problem),  or a workaround (possibly changing
our config file to allow access to the shares differently -- see below).

We have our shares setup to allow access by all users as themselves
without having to enter a password.  The following is our configuration
section for the share in question:

    [usr2]
      comment = Clearcase
      guest ok = yes
      guest account = %U	      <- Force guest account to that of
the user requesting access
      guest only = yes            <- Force all clients to use guest
account
      browseable = yes
      path = /usr2
      read only = no
      public = yes

As you can see we are forcing all users to access the share as the guest
account (to avoid asking for a password), and using the %U template to
let the access as their own account.  Is there a better way to do this,
this was the first thing I could come up with and if there is a better
way (possibly avoiding all of the guest account stuff), maybe it would
avoid this problem all together.

We put a sniffer on the wire and found that on successful connects to
the smbd, there is a frame which includes both a  Setup account, and
Connect request as below:

	SUMMARY  Delta T      Destination   Source        Summary
	    10    0.00324  pancake         [192.9.200.101]  SMB C Setup
account PAYSON
	                                                    SMB C
Connect ?????\\140.102.132.10\IPC$

	SMB:  ----- SMB Session Setup & more Command -----
	SMB:  
	SMB:  Function = 73 (Session Setup & more)
	SMB:  Tree id      (TID) = 0000
	SMB:  Process id   (PID) = CAFE
	SMB:  Flags2 = 0003
	SMB:   0... ....  .... .... = Application does not understand
Unicode strings
	SMB:   .0.. ....  .... .... = Application does not understand NT
status codes
	SMB:   ..0. ....  .... .... = Application does not do paging I/O
	SMB:   .... ....  .... ..1. = Application understands extended
attributes
	SMB:   .... ....  .... ...1 = Application understands OS/2 1.2
file names
	SMB:  Word count = 13
	SMB:  Flags = 1X
	SMB:  ...1 .... = Pathnames are already in canonicalized format
	SMB:  Maximum size of consumer buffer = 61440 bytes
	SMB:  Maximum number of multiplexed pending requests = 2
	SMB:  Type = 0: First (only) virtual circuit
	SMB:  Session key = 000042BC
	SMB:  Capabilities (low order word) = 00D4
	SMB:           .... ....  1... .... = Level II oplocks supported
	SMB:           .... ....  .1.. .... = NT status codes recognized
	SMB:           .... ....  ...1 .... = NT SMBs supported
	SMB:           .... ....  .... 0... = Large files not supported
	SMB:           .... ....  .... .1.. = Unicode strings recognized
	SMB:  Empty case insensitive password
	SMB:  Empty case sensitive password
	SMB:  Account name = "PAYSON"
	SMB:  Domain name = CHICAGO-DEV
	SMB:  Native operating system = "Windows NT 1381"
	SMB:  Native LAN manager = ""
	SMB:  
	SMB:  Extra word parameter = 00D4
	SMB:  Extra word parameter = 0000
	Sniffer Network Analyzer data from 16-Dec-97 at 16:38:18, file
C:\FDCAP\PANCAKE3.FDC, Page 8

	SMB:  
	SMB:  *** The SMB byte count records 16 extra data bytes
	SMB:  Extra string parameter = [Invalid data type]
	SMB:  
	SMB:  ----- SMB Tree Connect & more Command -----
	SMB:  
	SMB:  Function = 75 (Tree Connect & more)
	SMB:  Word count = 4
	SMB:  Connect flags = 0000
	SMB:   .... ....  .... ...0 = Do not disconnect TID
	SMB:  Password = ""
	SMB:  Server = "\\140.102.132.10\IPC$"
	SMB:  Service (device) = "?????"
	SMB:  
	SMB:  ----- End of SMB chain -----
	SMB:  

After this frame, the smbd responds with a Setup OK and Connect OK
packet.  This is what we see during successful attempts.  On failed
attempts to connect, we see a frame go by which only contains a Connect
request, no Setup request (why wouldn't there be a setup request, does
the client still think it has a connection?).  This frame, and the
corresponding deny reply from the smbd are shown below:

	SUMMARY  Delta T      Destination   Source        Summary
	   283    0.00136  pancake         [140.102.54.41]  SMB C
Connect ?????\\PANCAKE\USR2

	SMB:  ----- SMB Tree Connect & more Command -----
	SMB:  
	SMB:  Function = 75 (Tree Connect & more)
	SMB:  Tree id      (TID) = 0000
	SMB:  Process id   (PID) = CAFE
	SMB:  User id      (UID) = 09A0
	SMB:  Multiplex id (MID) = 001C
	SMB:  Flags2 = 0003
	SMB:   0... ....  .... .... = Application does not understand
Unicode strings
	SMB:   .0.. ....  .... .... = Application does not understand NT
status codes
	Sniffer Network Analyzer data from 16-Dec-97 at 16:17:32, file
C:\FDCAP\PANCAK1.FDC, Page 184


	SMB:   ..0. ....  .... .... = Application does not do paging I/O
	SMB:   .... ....  .... ..1. = Application understands extended
attributes
	SMB:   .... ....  .... ...1 = Application understands OS/2 1.2
file names
	SMB:  Word count = 4
	SMB:  Connect flags = 0000
	SMB:   .... ....  .... ...0 = Do not disconnect TID
	SMB:  Password = ""
	SMB:  Server = "\\PANCAKE\USR2"
	SMB:  Service (device) = "?????"
	SMB:  
	SMB:  ----- End of SMB chain -----
	SMB:  

	- - - - - - - - - - - - - - - - Frame 284 - - - - - - - - - - -
- - - - - -

	SUMMARY  Delta T      Destination   Source        Summary
	   284    0.10810  [140.102.54.41] pancake          SMB R Bad
password

	SMB:  ----- SMB Tree Connect & more Response -----
	SMB:  
	SMB:  Function = 75 (Tree Connect & more)
	SMB:  Tree id      (TID) = 0000
	SMB:  Process id   (PID) = CAFE
	SMB:  User id      (UID) = 09A0
	SMB:  Multiplex id (MID) = 001C
	SMB:  Flags2 = 0001
	SMB:   0... ....  .... .... = Application does not understand
Unicode strings
	SMB:   .0.. ....  .... .... = Application does not understand NT
status codes
	SMB:   ..0. ....  .... .... = Application does not do paging I/O
	SMB:   .... ....  .... ..0. = Application does not understand
extended attributes
	SMB:   .... ....  .... ...1 = Application understands OS/2 1.2
file names
	SMB:  Return code: Class = 2, Error = 2 (Bad password)
	SMB:  2 bytes of Remaining SMB Data.
	SMB:  
	SMB:  ----- End of SMB chain -----
	SMB: 

Thanks for your help.

-----
Marc Rossi
312.234.2933
NationsBank                                            Information
Services
233 S. Wacker Dr., Suite 2600                   Network Systems
Programming
Chicago, IL 60606                                   Internet:
marcr at crt.com


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