There is a low filter driver for the cdrom. The driver can hold the data read from the disc and decrypted the content. Because it will not receive IRP_MJ_READ irp but IRP_MJ_SCSI irp.
So, if the driver want to hold the data read from the physical disc, when and where the driver can hold the data?
thanks
xiaosan wrote:
So, if the driver want to hold the data read from the physical disc, when
and where the driver can hold the data?
How about in a buffer?
in fact im not sure. I have not written such a filter driver but now i will have deal with it. I have a example driver can do this but have no source code. So, i want to know when and where it hold the data before do some additional task on it.
any idea?
Your question is very unclear. Most likely it is a language issue. The
filter driver most likely allocates a buffer and decrypts the data into the
buffer. It presumably does this on the completion side of IRP_MJ_SCSI
operations.
On Fri, Nov 7, 2008 at 9:47 PM, wrote:
> in fact im not sure. I have not written such a filter driver but now i will
> have deal with it. I have a example driver can do this but have no source
> code. So, i want to know when and where it hold the data before do some
> additional task on it.
> any idea?
>
> —
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Mark Roddy
i found more than one IRP_MJ_SCSI irp command was send to the driver when a user mode app calls ReadFile to read one byte from a file of the disc.
Yes, it should be. im sorry for my bad english. There is such a filter
driver really do decryption before returning data to user app. I want to
know when and where it got the original data from the disc, so i trace into
the IRP_MJ_SCSI rountine(am i right?). but i really don’t know the exact
spot the driver just got the data from the disc.
On Sat, Nov 8, 2008 at 5:36 AM, Mark Roddy wrote:
> Your question is very unclear. Most likely it is a language issue. The
> filter driver most likely allocates a buffer and decrypts the data into the
> buffer. It presumably does this on the completion side of IRP_MJ_SCSI
> operations.
>
>
> On Fri, Nov 7, 2008 at 9:47 PM, wrote:
>
>> in fact im not sure. I have not written such a filter driver but now i
>> will have deal with it. I have a example driver can do this but have no
>> source code. So, i want to know when and where it hold the data before do
>> some additional task on it.
>> any idea?
>>
>> —
>> 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
>>
>
>
>
> –
> Mark Roddy
> — 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