I need to build a special udp echo server in kernel space.
I wrote a netfilter module that intercept all udp packets with a specific port. Than modify the packets a bit and switch the destination and source port and ip.
it works fine, but I got stuck here. I don't know how to send this packet out now. I tried to look on the web for some tutorial or samples but with no luck.
please anyone can help me by either tell me how to send packets using the netfilter or direct me into other way to do my server.
Thanks in advance.