Function tcp_timer_2msl

freebsd/netinet/tcp_timer.c:308–397

}

void
tcp_timer_2msl(void *xtp)
{
	struct tcpcb *tp = xtp;
	struct inpcb *inp;
	struct epoch_tracker et;
	CURVNET_SET(tp->t_vnet);
#ifdef TCPDEBUG
	int ostate;

	ostate = tp->t_state;
#endif
	inp = tp->t_inpcb;
	KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
	INP_WLOCK(inp);
	tcp_free_sackholes(tp);
	if (callout_pending(&tp->t_timers->tt_2msl) ||
	    !callout_active(&tp->t_timers->tt_2msl)) {
		INP_WUNLOCK(tp->t_inpcb);
		CURVNET_RESTORE();
		return;
	}
	callout_deactivate(&tp->t_timers->tt_2msl);
	if ((inp->inp_flags & INP_DROPPED) != 0) {
		INP_WUNLOCK(inp);
		CURVNET_RESTORE();
		return;
	}
	KASSERT((tp->t_timers->tt_flags & TT_STOPPED) == 0,
		("%s: tp %p tcpcb can't be stopped here", __func__, tp));
	/*
	 * 2 MSL timeout in shutdown went off.  If we're closed but
	 * still waiting for peer to close and connection has been idle
	 * too long delete connection control block.  Otherwise, check
	 * again in a bit.
	 *
	 * If in TIME_WAIT state just ignore as this timeout is handled in
	 * tcp_tw_2msl_scan().
	 *
	 * If fastrecycle of FIN_WAIT_2, in FIN_WAIT_2 and receiver has closed,
	 * there's no point in hanging onto FIN_WAIT_2 socket. Just close it.
	 * Ignore fact that there were recent incoming segments.
	 */
	if ((inp->inp_flags & INP_TIMEWAIT) != 0) {
		INP_WUNLOCK(inp);
		CURVNET_RESTORE();
		return;
	}
	if (tcp_fast_finwait2_recycle && tp->t_state == TCPS_FIN_WAIT_2 &&
	    tp->t_inpcb && tp->t_inpcb->inp_socket &&
	    (tp->t_inpcb->inp_socket->so_rcv.sb_state & SBS_CANTRCVMORE)) {
		TCPSTAT_INC(tcps_finwait2_drops);
		if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
			tcp_inpinfo_lock_del(inp, tp);
			goto out;
		}
		NET_EPOCH_ENTER(et);
		tp = tcp_close(tp);