Function tcp_usr_abort

freebsd/netinet/tcp_usrreq.c:1382–1420

* Abort the TCP. Drop the connection abruptly. */

 * Abort the TCP.  Drop the connection abruptly.
 */
static void
tcp_usr_abort(struct socket *so)
{
	struct inpcb *inp;
	struct tcpcb *tp = NULL;
	struct epoch_tracker et;
	TCPDEBUG0;

	inp = sotoinpcb(so);
	KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));

	NET_EPOCH_ENTER(et);
	INP_WLOCK(inp);
	KASSERT(inp->inp_socket != NULL,
	    ("tcp_usr_abort: inp_socket == NULL"));

	/*
	 * If we still have full TCP state, and we're not dropped, drop.
	 */
	if (!(inp->inp_flags & INP_TIMEWAIT) &&
	    !(inp->inp_flags & INP_DROPPED)) {
		tp = intotcpcb(inp);
		TCPDEBUG1();
		tp = tcp_drop(tp, ECONNABORTED);
		if (tp == NULL)
			goto dropped;
		TCPDEBUG2(PRU_ABORT);
		TCP_PROBE2(debug__user, tp, PRU_ABORT);
	}
	if (!(inp->inp_flags & INP_DROPPED)) {
		SOCK_LOCK(so);
		so->so_state |= SS_PROTOREF;
		SOCK_UNLOCK(so);
		inp->inp_flags |= INP_SOCKREF;
	}
	INP_WUNLOCK(inp);
dropped:
	NET_EPOCH_EXIT(et);
}

/*
 * TCP socket is closed.  Start friendly disconnect.