capturing and manipulating packets in openbsd
Posted on 2003-11-13
i am currently doing my Thesis, and part of it includes the following
steps: (OS= OpenBSD 3.3, or 3.4).
It is based on following structure:
I installed that using example of brconfig...now my major tasks are
ahead (changes to do):
Scenario: start a telnet session from client 1 to client 2
1. get packets getting in interface fxp1 from IP stack (kernelspace) and get each packet into
2. parsing or decoding the IP packets in user space.
3. changing the IP packet (adding a specific string to it, or to
4. injecting packet back to IP stack .
Now i have been told i can do step 1 and 2 using tun device, or bpf
How do i achieve the other steps?any code samples?