[jcifs] Possible bug in jcifs.smb.SmbComOpenAndX

Michael B Allen ioplex at gmail.com
Thu Aug 27 10:54:09 MDT 2009

On Thu, Aug 27, 2009 at 9:58 AM, Andy Thomson<a10008051 at gmail.com> wrote:
> Mike,
> It looks like that the declared "int flags" in SmbComOpenAndX is not used, and
> it may be stepping on the declared "byte flags" from ServerMessageBlock.  This
> appears to be the case in the writeParameterWordsWireFormat() method.
> I did not find any "upstream" usages of it [int flags], and the lower ones
> reference the correct ServerMessageBlock one [byte flags].  This one [int flags]
> is not set, which implies that the writeParameterWordsWireFormat() is always
> seeing a default setting, and never the intended one, at least not that I can
> tell.  ServeMessageBlock does call the writeParameterWordsWireFormat() method
> via the encode() method, not sure the result is always what was intended.
> The class SmbComOpenAndX extends AndXServerMessageBlock, and
> AndXServerMessageBlock extends ServerMessageBlock.  ServerMessageBlock has a
> variable "byte flags" defined in it.
> class SmbComOpenAndX extends AndXServerMessageBlock {
>  ...
>  int flags,               <<< should be removed ???
>  desiredAccess,
>  searchAttributes,
>  fileAttributes,
>  creationTime,
>  openFunction,
>  allocationSize;
>  ...
>  int writeParameterWordsWireFormat( byte[] dst, int dstIndex ) {
>    int start = dstIndex;
>    writeInt2( flags, dst, dstIndex );   <<< which flag? use empty
>                                             local one? or one from
>                                             ServerMessageBlock?

Hi Andy,

No, it should not be removed. But I can understand why you're
confused. There is a 'byte flags' of ServerMessageBlock.java that
represents the 'Flags' field in the SMB header. But SMB_COM_OPEN_ANDX
also has a 'Flags' field which is completely different and for our
purposes is always 0. And because the local 'int flags' is not
explicitly initialized, it should be 0 which is the correct value that
should go out on the wire. The field should probably be called
something else but I tried to follow the naming convention set by the
Leach Naik draft so the name 'flags' just happened to be the same.

Are you experiencing a particular problem? Are you trying to set the
SMB_COM_OPEN_ANDX flags? Currently there is no way to set that field
since it's used for oplocks and stuff we don't use. That command as a
whole is also largely obsolete. If you're doing command-level
programming, try to use SMB_COM_NT_CREATE_ANDX.


Michael B Allen
Java Active Directory Integration

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