Windows System Software -- Consulting, Training, Development -- Unique Expertise, Guaranteed Results

Home NTDEV
Before Posting...
Please check out the Community Guidelines in the Announcements and Administration Category.

More Info on Driver Writing and Debugging


The free OSR Learning Library has more than 50 articles on a wide variety of topics about writing and debugging device drivers and Minifilters. From introductory level to advanced. All the articles have been recently reviewed and updated, and are written using the clear and definitive style you've come to expect from OSR over the years.


Check out The OSR Learning Library at: https://www.osr.com/osr-learning-library/


Another BSOD on Inserting Packets in LWF

Steve_ValleySteve_Valley Member - All Emails Posts: 6
I have written some very simple code (famous last words) to modify a SYN packet coming down the tcpip stack. I create a new buffer list and store the original in the context space of the new nbl to free in my FilterSendNetBufferListsComplete routine. This seems to work sometimes. I get a blue screen on this call after traffic starts to pick up. I see that if the nbl I created is freed before other nbls queued on my pFilter, then everything works fine. If another nbl is freed before I get mine back. I get a BSOD. Do I need to wait to get my packet back from the FilterSendNetBufferLists call before another call to FilterSendNetBufferLists is made? I am new at this so I apologize for the question if it is stupid or answered before. I have looked through many of the prior posting, and the code in some of those threads is very similar to mine. Thanks.
Sign In or Register to comment.

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Upcoming OSR Seminars
OSR has suspended in-person seminars due to the Covid-19 outbreak. But, don't miss your training! Attend via the internet instead!
Kernel Debugging 30 Mar 2020 OSR Seminar Space
Developing Minifilters 15 Jun 2020 LIVE ONLINE
Writing WDF Drivers 22 June 2020 LIVE ONLINE
Internals & Software Drivers 28 Sept 2020 Dulles, VA