On Fri, Sep 20, 2019 at 11:43:50PM +0000, Swarm wrote: > First time emailing to this mailing list so please let me know if I made a > mistake in how I sent it. I'm trying to receive a notification from the > kernel once it verifies an ACK packet in a handshake. Problem is, there is no > API or kernel resource I've seen that supports this feature for both > syncookies and normal handshakes. Where exactly in the kernel does the ACK > get verified? If there isn't a way to be notified of it, where should I start > adding that feature into the kernel?
Just searching for TCP_ESTABLISHED immediately brought me to tcp_input.c (tcp_rcv_state_process() to be precise), so I'm not sure you've searched that much. As you've noticed there's nothing specifically called in this case, but in practice a caller of accept() on a listening socket will be woken up. Hoping this helps, Willy
