Driver Filter and Application

[forum_visitor]

I need to know how driver filter(upper-level) and my application can exchange info between each other ?

For example : driver filter to filter messages from/to Com port. In my App I need to be able to recieve/send data from/to this filter driver. Where I can read about this/ Maybe some code example ?

[Mick]

Well there are a number of methods.

1) Buffers (DeviceIoControl)
2) Section Objects (FileMappings)
3) Lpc

This is a very common question asked so you should have no problems finding information on it just google on these keywords.

user mode kernel mode driver communication

I believe this old link has DeviceIO/Event user/kernel notification source in it.

http://www.microsoft.com/msj/0799/nerd/nerd0799.aspx

I use both DeviceIoControl (1) and LPC(3) but those things depend on your requirements.

[forum_visitor]

Thank You very much Mick!
I have one more question.
Situation :
1. In my system there are some virtual com ports(like com 9, com10, etc.)
2. Client application is connected to the for example com9
3. I need that my application would be able to recieve/send data from/to this com9.

As I know, two different applications can not use one com port at the same time. So is it is possible somehow to solve this problem ?

[Mick]

Thank You very much Mick!
I have one more question.
Situation :
1. In my system there are some virtual com ports(like com 9, com10, etc.)
2. Client application is connected to the for example com9
3. I need that my application would be able to recieve/send data from/to this com9.

As I know, two different applications can not use one com port at the same time. So is it is possible somehow to solve this problem ?

I do not have any experience with writing/interacting with serial drivers.I can not give you a concrete answer until I have had time to modify code and run it myself (always the best way to investigate something) and I have no idea when/how long that would take right now.

But I would say look at the DDK docs under the serial/parallel section. There are also two samples:

Serenum.sys which is a Plug and Play upper-level device filter driver that works with Serial.sys.