How to verify TCP Reassembly

Hello:

We have a custom TCP stack and would like to verify our TCP Reassembly
functionality.

Can somone please give some ideas on how to test this. The scenarios to
be created and tested are creating out of order pkts, packets with
overlapping sequence numbers etc.

I looked at using divert sockets. Probably that is one of the ways to
generate such pkts. But, I am not very sure how it would work for us
(or does it even work in this situation?).

Could someone please share their experiences with using divert socket
to do something like this.
Also, if someone would like to share their experiences ways of testing
TCP reassembly, I will really appreicate it.

Thanks for your help,
Vishal.