2008/12/24 Srinivas G. <[email protected]>: > Dear All > > > > Is there any concept of filter driver in case of Linux like in windows OS. > In windows we can write a filter driver to enhance the behavior of existing > driver and this filter driver can be attached to main driver either above or > below. But I don't see similar concept in Linux.
In Windows, there is a device object that is created by default for devices; device driver (DD) writers write modules for this `object', the core component (another object) being the function object, to provide functionality. In Linux, one doesn't do that. The primary abstractions available to the DD writer are those of a character, block or a network device. The writer then builds on top of this abstraction. And of course, they are free to use their own objects on top of this. So, the filter functionality, *has* to be provided by the DD writer, should anyone be able to add more functionality. And, I believe there is an abstraction for notifiers (not exactly a filter per se, but something similar) available in the linux kernel. I have seen that keyboard.c provides an interface by which an external module can register for callbacks for specific events. You might want to check that out. -- Vimal -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to [email protected] Please read the FAQ at http://kernelnewbies.org/FAQ
