[jcifs] Large Write_Andx messages

[Michael B Allen]

On Sun, 28 Oct 2007 21:18:06 +0100
"Mikael Klamra" <mklamra at gmail.com> wrote:

> Hi,
> I'm implementing a CIFS client. I have some problems with WRITE_ANDX
> messages that I hope someone can help me with. The negotiated maximum
> buffer size between my client and the server (a Windows Server 2003
> R2) is 4356 bytes. I have set the CAP_LARGE_WRITEX and CAP_LARGE_READX
> bits in the client's capabilities, which means that a WRITE_ANDX
> message from the client can be up to 64 KB. However, I get
> a non-specific error (ERRSRV/ERRerror) back from the server when I try
> to send a WRITE_ANDX message with two or more blocks when the total
> message size is about 4700 bytes or greater. It works without problems
> when the message size is small. Are there any obscure rules for
> WRITE_ANDX messages, such as padding rules? I've aligned the data
> buffer of each block to the nearest 4-byte boundary. Do I have to
> align the beginning of each block too? I'm using the 12-byte WordCount
> version of WRITE_ANDX.
> 
> I have tried to sniff similar messages between Windows XP and Windows
> Server 2003 R2, but Windows does not seem to put several blocks in
> WRITE_ANDX messages. Does jCIFS use WRITE_ANDX messages with several
> blocks? If yes, how are the messages structured?

Hi Mikael,

I have no experience with the CAP_LARGE_* messages but someone submitted a
patch for JCIFS to support them. The patch was never integrated but it is
in the patches directory. Perhaps you can find what you need from studying
it. Not sure if it still applies cleanly to the most recent JCIFS.

Mike

-- 
Michael B Allen
PHP Active Directory SPNEGO SSO
http://www.ioplex.com/