Microsoft Ramdisk Share

Bryan_Lenzi · October 12, 2007, 6:47pm

I posted this on NTFSD and was advised I might get more help over here…

Hello everyone,

I have four machines I am developing on:

Machine 1 - XP Pro
Machine 2 - XP Pro
Machine 3 - XP Pro
Machine 4 - 2003

I installed microsoft’s kmdf ramdisk sample on each of these machines and tried to share the drive. On all machines, the drive successfully shared, but user access was restricted in the following ways:
Machine 1 - I could access the share.
Machine 2 - No one could access the share
Machine 3 - No one could access the share
Machine 4 - No one could access the share

On machine 1, I could access the ramdisk, but no one else on the domain could, despite giving EVERYONE full access to the drive and also adding individual domain users to the drive. On the other machines though, not even I could access the share.

This brings on two questions:

Why can I access the share on machine 1, but no other machine?
How come no one else on the domain can access any shared ramdisk?

I should also mention that I have windows firewall turned off on all machines, I have tried every possible combination of security (i.e. added EVERYONE for full control, added individual domain users, etc.) and I have reset the security policies back to the windows default. Also, I am able to successfully share and access any other drive/folder on any of the machines, just the ramdisk is giving me trouble.

Any help would be appreciated.

Bryan

Bryan_Lenzi · October 15, 2007, 10:31am

Anyone?

Doron_Holan · October 15, 2007, 12:32pm

weird, i responded last week:

This could be due to FILE_DEVICE_SECURE_OPEN being set, read

http://blogs.msdn.com/doronh/archive/2007/10/03/devices-and-namespaces.aspx
http://blogs.msdn.com/doronh/archive/2007/10/04/making-sure-the-io-manager-evaluates-the-security-of-your-device.aspx

and clear the flag as shown in the last post and see if that helps

d

Bryan_Lenzi · October 17, 2007, 2:18pm

Thanks for replying Doron,

I went ahead and tried putting in the line of code the second post specified and tried it again. It is still not allowing me access to the ramdisk on any of the last three machines, but it still allows access on machine 1.

Any other ideas would be appreciated.

Bryan

Doron_Holan · October 17, 2007, 2:28pm

Sorry, don’t know.

d

-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@hotmail.com
Sent: Wednesday, October 17, 2007 11:20 AM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] Microsoft Ramdisk Share

Thanks for replying Doron,

I went ahead and tried putting in the line of code the second post specified and tried it again. It is still not allowing me access to the ramdisk on any of the last three machines, but it still allows access on machine 1.

Any other ideas would be appreciated.

Bryan

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Bryan_Lenzi · October 17, 2007, 3:25pm

Thanks Doron,

I was kind of hoping that someone out there had messed around with Microsoft’s kmdf ramdisk example enough to have some experience with sharing.

If you have messed around with it:

Were you able to successfully share it like I have?
Were you able to successfully access the share?
Were other people on the network able to access the share?

Any help you could give would be appreciated.

Bryan

OSR_Community_User · October 17, 2007, 4:13pm

Just a though that you have probably already checked. Do all the
machines either have “Simple File Sharing” enabled or disabled? In
particular, do the ones that fails have it enabled, and the Guest
account disabled, because under SFS every authenticates remotely as Guest.

Good luck,

mm
xxxxx@hotmail.com wrote:

Thanks Doron,

I was kind of hoping that someone out there had messed around with Microsoft’s kmdf ramdisk example enough to have some experience with sharing.

If you have messed around with it:

Were you able to successfully share it like I have?
Were you able to successfully access the share?
Were other people on the network able to access the share?

Any help you could give would be appreciated.

Bryan

Bryan_Lenzi · October 17, 2007, 4:38pm

Thanks for the reply mm,

I doubled checked, and simple file sharing is turned on for every machine.

I also checked the guest account, and it is enabled on every machine.

Bryan

OSR_Community_User · October 17, 2007, 4:44pm

Sorry I don’t have anything better. One more. Is the (something like)
“Allow Blank Passwords only at Console” security option set in
GPEDIT.MSC? Also, it possible under the user part of policy to deny
specific users access from the network.

Good luck,

mm
xxxxx@hotmail.com wrote:

Thanks for the reply mm,

I doubled checked, and simple file sharing is turned on for every machine.

I also checked the guest account, and it is enabled on every machine.

Bryan

Michal_Vodicka-2 · October 17, 2007, 5:15pm

If I have to solve similar problem, I’d probably use Network Monitor to see real communication at network level. If access to share is refused, there could be visible the real reason. Years before when I worked on network software it was surprisigly successful approach. It is good to know something about protocols used but it may not be necessary; NetMon makes very good job with decoding them. You can compare successful access to different share with access to RamDisk and examine differences. It should help to identify the point where the access was refused and at least an error code.

Oh please don’t ask me about details, I didn’t have a need to use NetMon for years and my memory leaks quickly Google is your friend.

Best regards,

Michal Vodicka
UPEK, Inc.
[xxxxx@upek.com, http://www.upek.com]

From: xxxxx@lists.osr.com[SMTP:xxxxx@lists.osr.com] on behalf of xxxxx@hotmail.com[SMTP:xxxxx@hotmail.com]
Reply To: Windows System Software Devs Interest List
Sent: Wednesday, October 17, 2007 10:40 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] Microsoft Ramdisk Share

Thanks for the reply mm,

I doubled checked, and simple file sharing is turned on for every machine.

I also checked the guest account, and it is enabled on every machine.

Bryan

NTDEV is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

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OSR_Community_User · October 17, 2007, 5:35pm

Good idea, Michal. For those of us who are not particularly network
inclined, such as myself, you could do a very poor man’s version of this
quickly by enabling security auditing and see if event viewer has
anything useful to say buried among the reams of generally useless
security events that get generated constantly. I know nothing about
NetMon, especially what it has to offer and about its learning curve,
and the event viewer method has serious limitations. I mention it only
for consideration if the learning curve is what stops you for the
immediate future, as it probably would me - problems like this are the
reason that I run from networking like it’s the plauge if it’s at all
possible for me to do so.

For what it’s worth and good luck,

mm

Michal Vodicka wrote:

If I have to solve similar problem, I’d probably use Network Monitor to see real communication at network level. If access to share is refused, there could be visible the real reason. Years before when I worked on network software it was surprisigly successful approach. It is good to know something about protocols used but it may not be necessary; NetMon makes very good job with decoding them. You can compare successful access to different share with access to RamDisk and examine differences. It should help to identify the point where the access was refused and at least an error code.

Oh please don’t ask me about details, I didn’t have a need to use NetMon for years and my memory leaks quickly Google is your friend.

Best regards,

Michal Vodicka
UPEK, Inc.
[xxxxx@upek.com, http://www.upek.com]

> ----------
> From: xxxxx@lists.osr.com[SMTP:xxxxx@lists.osr.com] on behalf of xxxxx@hotmail.com[SMTP:xxxxx@hotmail.com]
> Reply To: Windows System Software Devs Interest List
> Sent: Wednesday, October 17, 2007 10:40 PM
> To: Windows System Software Devs Interest List
> Subject: RE:[ntdev] Microsoft Ramdisk Share
>
> Thanks for the reply mm,
>
> I doubled checked, and simple file sharing is turned on for every machine.
>
> I also checked the guest account, and it is enabled on every machine.
>
> Bryan
>
> —
> NTDEV is sponsored by OSR
>
> For our schedule of WDF, WDM, debugging and other seminars visit:
> http://www.osr.com/seminars
>
> To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer
>