For a path like this:
\Device\Mup\MyMachine\MyShare\myfile.txt
In my machine “\Device\Mup\MyMachine\MyShare” is mapped as “X:”.
Should FilterGetDosName give anything ? (for example returning “X”)
I get “Invalid parameter”.
(Note that it works if I pass a path like \Device\HarddiskVolume1"; in this case it returns “C:” in my machine )
Inaki.
This is expected behavior.
You should know that there can be multiple letters associated with a
symlink. Substed drives for example.
If you require a file name for anything other than an
enforced-policy environment (where you are sure letters won’t change),
DOS names are meaningless because an admin can simply change then.
–
Kind regards, Dejan (MSN support: xxxxx@alfasp.com)
http://www.alfasp.com
File system audit, security and encryption kits.
Expected behavior? And then why it works for local disks paths?
Because, AFAIK, local disks paths also may have multiple DOS names.
Moreover, then why FilterGetDosName exists at all ?
With regards to your second observation. Although DOS names may change from user to user, and from a session to another, they are VERY useful precisely for users!. Note that in my driver I may work internally with absolute names but the user does not know anything about the existence of Device\harddiskxxx and the like. To the user I must report the friendlest name as possible whenever it is available.
Inaki.
-----Mensaje original-----
De: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] En nombre de Dejan Maksimovic
Enviado el: martes, 16 de octubre de 2007 7:07
Para: Windows File Systems Devs Interest List
Asunto: Re: [ntfsd] Does FilterGetDosName work for MUP paths?
This is expected behavior.
You should know that there can be multiple letters associated with a
symlink. Substed drives for example.
If you require a file name for anything other than an
enforced-policy environment (where you are sure letters won’t change),
DOS names are meaningless because an admin can simply change then.
–
Kind regards, Dejan (MSN support: xxxxx@alfasp.com)
http://www.alfasp.com
File system audit, security and encryption kits.
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> Expected behavior? And then why it works for local disks paths?
Because local disk paths HAVE DOS names?
Because, AFAIK, local disks paths also may have multiple DOS names.
Moreover, then why FilterGetDosName exists at all ?
Because some people implemented it wrong. But, frankly speaking DOS names are only indicative, they are not decisive! If you perform data monitoring in a controlled environment it’s OK, but not elsewhere and not for any purpose.
With regards to your second observation. Although DOS names may change from user to user, and from a session to another, they are VERY useful precisely for users!. Note that in my driver I may work internally with absolute names but the user does not know anything about the existence of Device\harddiskxxx and the like. To the user I must report the friendlest name as possible whenever it is available.
And if different users map different letters to the same location? Will you call FltGetDosName for EVERY I/O call? Go ahead… I assume it will slow down the machine some 30-40%.
–
Kind regards, Dejan (MSN support: xxxxx@alfasp.com)
http://www.alfasp.com
File system audit, security and encryption kits.