Help with FltSendMessage and FilterGetMessage

NTFSD
1

Hello,

Im currently working on a simple minifilter driver that will kick back
information during the postop to a process in user mode. I was hoping to
use FltSendMessage and FilterGetMessage (using the optional OVERLAPPED
structure) to achieve asynchronous communication between the 2. This is my
first experience with writing drivers and Im a little overwhelmed at times.

The current problem Im having if figuring out how to allocate the send
message buffer thats required by FltSendMessage. Where should it occur?
How can I create a buffer that accessable by both the user and kernel mode?
Thank you.

Rob

2

Hi Robert,

I would suggest you take a look at the scanner example in the wdk first.
This demonstrates send and get message using overlapped IO.

That example should answer all your questions.

Good luck,
m

Robert Light wrote:

Hello,

Im currently working on a simple minifilter driver that will kick back
information during the postop to a process in user mode. I was hoping
to use FltSendMessage and FilterGetMessage (using the optional
OVERLAPPED structure) to achieve asynchronous communication between
the 2. This is my first experience with writing drivers and Im a
little overwhelmed at times.

The current problem Im having if figuring out how to allocate the send
message buffer thats required by FltSendMessage. Where should it
occur? How can I create a buffer that accessable by both the user and
kernel mode? Thank you.

Rob

Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17

You are currently subscribed to ntfsd as: xxxxx@comcast.net
To unsubscribe send a blank email to xxxxx@lists.osr.com

3

Thanks for the help. Were looking at it now and it seems to be what the
doctored ordered.
“MM” wrote in message news:xxxxx@ntfsd…
> Hi Robert,
>
> I would suggest you take a look at the scanner example in the wdk first.
> This demonstrates send and get message using overlapped IO.
>
> That example should answer all your questions.
>
> Good luck,
> m
>
> Robert Light wrote:
>
>> Hello,
>>
>> Im currently working on a simple minifilter driver that will kick back
>> information during the postop to a process in user mode. I was hoping
>> to use FltSendMessage and FilterGetMessage (using the optional
>> OVERLAPPED structure) to achieve asynchronous communication between
>> the 2. This is my first experience with writing drivers and Im a
>> little overwhelmed at times.
>>
>> The current problem Im having if figuring out how to allocate the send
>> message buffer thats required by FltSendMessage. Where should it
>> occur? How can I create a buffer that accessable by both the user and
>> kernel mode? Thank you.
>>
>> Rob
>>
>> —
>> Questions? First check the IFS FAQ at
>> https://www.osronline.com/article.cfm?id=17
>>
>> You are currently subscribed to ntfsd as: xxxxx@comcast.net
>> To unsubscribe send a blank email to xxxxx@lists.osr.com
>>
>