I'm working on a TCP/IP implementation, for an embedded device, that I want to test from a Linux user space process using raw sockets.
raw(7) says that
Raw sockets may tap all IP protocols in Linux, even protocols like ICMP or TCP which have a protocol module in the kernel. In this case, the packets are passed to both the kernel module and the raw socket(s).
I need to disable this kernel processing (at least on a specific destination port) in order to test my implementation. I think there's some manipulation involving iptables which can do this, but frankly I'm no Linux guru. I appreciate any help.