Пример #1
0
void
tcp_timer_rexmt(void * xtp)
{
	struct tcpcb *tp = xtp;
	CURVNET_SET(tp->t_vnet);
	int rexmt;
	int headlocked;
	struct inpcb *inp;
#ifdef TCPDEBUG
	int ostate;

	ostate = tp->t_state;
#endif
	INP_INFO_RLOCK(&V_tcbinfo);
	inp = tp->t_inpcb;
	/*
	 * XXXRW: While this assert is in fact correct, bugs in the tcpcb
	 * tear-down mean we need it as a work-around for races between
	 * timers and tcp_discardcb().
	 *
	 * KASSERT(inp != NULL, ("tcp_timer_rexmt: inp == NULL"));
	 */
	if (inp == NULL) {
		tcp_timer_race++;
		INP_INFO_RUNLOCK(&V_tcbinfo);
		CURVNET_RESTORE();
		return;
	}
	INP_WLOCK(inp);
	if (callout_pending(&tp->t_timers->tt_rexmt) ||
	    !callout_active(&tp->t_timers->tt_rexmt)) {
		INP_WUNLOCK(inp);
		INP_INFO_RUNLOCK(&V_tcbinfo);
		CURVNET_RESTORE();
		return;
	}
	callout_deactivate(&tp->t_timers->tt_rexmt);
	if ((inp->inp_flags & INP_DROPPED) != 0) {
		INP_WUNLOCK(inp);
		INP_INFO_RUNLOCK(&V_tcbinfo);
		CURVNET_RESTORE();
		return;
	}
	tcp_free_sackholes(tp);
	/*
	 * Retransmission timer went off.  Message has not
	 * been acked within retransmit interval.  Back off
	 * to a longer retransmit interval and retransmit one segment.
	 */
	if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) {
		tp->t_rxtshift = TCP_MAXRXTSHIFT;
		TCPSTAT_INC(tcps_timeoutdrop);
		in_pcbref(inp);
		INP_INFO_RUNLOCK(&V_tcbinfo);
		INP_WUNLOCK(inp);
		INP_INFO_WLOCK(&V_tcbinfo);
		INP_WLOCK(inp);
		if (in_pcbrele_wlocked(inp)) {
			INP_INFO_WUNLOCK(&V_tcbinfo);
			CURVNET_RESTORE();
			return;
		}
		if (inp->inp_flags & INP_DROPPED) {
			INP_WUNLOCK(inp);
			INP_INFO_WUNLOCK(&V_tcbinfo);
			CURVNET_RESTORE();
			return;
		}

		tp = tcp_drop(tp, tp->t_softerror ?
			      tp->t_softerror : ETIMEDOUT);
		headlocked = 1;
		goto out;
	}
	INP_INFO_RUNLOCK(&V_tcbinfo);
	headlocked = 0;
	if (tp->t_state == TCPS_SYN_SENT) {
		/*
		 * If the SYN was retransmitted, indicate CWND to be
		 * limited to 1 segment in cc_conn_init().
		 */
		tp->snd_cwnd = 1;
	} else if (tp->t_rxtshift == 1) {
		/*
		 * first retransmit; record ssthresh and cwnd so they can
		 * be recovered if this turns out to be a "bad" retransmit.
		 * A retransmit is considered "bad" if an ACK for this
		 * segment is received within RTT/2 interval; the assumption
		 * here is that the ACK was already in flight.  See
		 * "On Estimating End-to-End Network Path Properties" by
		 * Allman and Paxson for more details.
		 */
		tp->snd_cwnd_prev = tp->snd_cwnd;
		tp->snd_ssthresh_prev = tp->snd_ssthresh;
		tp->snd_recover_prev = tp->snd_recover;
		if (IN_FASTRECOVERY(tp->t_flags))
			tp->t_flags |= TF_WASFRECOVERY;
		else
			tp->t_flags &= ~TF_WASFRECOVERY;
		if (IN_CONGRECOVERY(tp->t_flags))
			tp->t_flags |= TF_WASCRECOVERY;
		else
			tp->t_flags &= ~TF_WASCRECOVERY;
		tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1));
		tp->t_flags |= TF_PREVVALID;
	} else
Пример #2
0
void
tcp_timer_persist(void *xtp)
{
	struct tcpcb *tp = xtp;
	struct inpcb *inp;
	CURVNET_SET(tp->t_vnet);
#ifdef TCPDEBUG
	int ostate;

	ostate = tp->t_state;
#endif
	INP_INFO_WLOCK(&V_tcbinfo);
	inp = tp->t_inpcb;
	/*
	 * XXXRW: While this assert is in fact correct, bugs in the tcpcb
	 * tear-down mean we need it as a work-around for races between
	 * timers and tcp_discardcb().
	 *
	 * KASSERT(inp != NULL, ("tcp_timer_persist: inp == NULL"));
	 */
	if (inp == NULL) {
		tcp_timer_race++;
		INP_INFO_WUNLOCK(&V_tcbinfo);
		CURVNET_RESTORE();
		return;
	}
	INP_WLOCK(inp);
	if (callout_pending(&tp->t_timers->tt_persist) ||
	    !callout_active(&tp->t_timers->tt_persist)) {
		INP_WUNLOCK(inp);
		INP_INFO_WUNLOCK(&V_tcbinfo);
		CURVNET_RESTORE();
		return;
	}
	callout_deactivate(&tp->t_timers->tt_persist);
	if ((inp->inp_flags & INP_DROPPED) != 0) {
		INP_WUNLOCK(inp);
		INP_INFO_WUNLOCK(&V_tcbinfo);
		CURVNET_RESTORE();
		return;
	}
	/*
	 * Persistance timer into zero window.
	 * Force a byte to be output, if possible.
	 */
	TCPSTAT_INC(tcps_persisttimeo);
	/*
	 * Hack: if the peer is dead/unreachable, we do not
	 * time out if the window is closed.  After a full
	 * backoff, drop the connection if the idle time
	 * (no responses to probes) reaches the maximum
	 * backoff that we would use if retransmitting.
	 */
	if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
	     ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) {
		TCPSTAT_INC(tcps_persistdrop);
		tp = tcp_drop(tp, ETIMEDOUT);
		goto out;
	}
	/*
	 * If the user has closed the socket then drop a persisting
	 * connection after a much reduced timeout.
	 */
	if (tp->t_state > TCPS_CLOSE_WAIT &&
	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
		TCPSTAT_INC(tcps_persistdrop);
		tp = tcp_drop(tp, ETIMEDOUT);
		goto out;
	}
	tcp_setpersist(tp);
	tp->t_flags |= TF_FORCEDATA;
	(void) tcp_output(tp);
	tp->t_flags &= ~TF_FORCEDATA;

out:
#ifdef TCPDEBUG
	if (tp != NULL && tp->t_inpcb->inp_socket->so_options & SO_DEBUG)
		tcp_trace(TA_USER, ostate, tp, NULL, NULL, PRU_SLOWTIMO);
#endif
	if (tp != NULL)
		INP_WUNLOCK(inp);
	INP_INFO_WUNLOCK(&V_tcbinfo);
	CURVNET_RESTORE();
}
Пример #3
0
/*
 * Read from so's socket into sb_snd, updating all relevant sbuf fields
 * NOTE: This will only be called if it is select()ed for reading, so
 * a read() of 0 (or less) means it's disconnected
 */
int
soread(PNATState pData, struct socket *so)
{
    int n, nn, lss, total;
    struct sbuf *sb = &so->so_snd;
    size_t len = sb->sb_datalen - sb->sb_cc;
    struct iovec iov[2];
    int mss = so->so_tcpcb->t_maxseg;

    STAM_PROFILE_START(&pData->StatIOread, a);
    STAM_COUNTER_RESET(&pData->StatIORead_in_1);
    STAM_COUNTER_RESET(&pData->StatIORead_in_2);

    QSOCKET_LOCK(tcb);
    SOCKET_LOCK(so);
    QSOCKET_UNLOCK(tcb);

    LogFlow(("soread: so = %R[natsock]\n", so));
    Log2(("%s: so = %R[natsock] so->so_snd = %R[sbuf]\n", RT_GCC_EXTENSION __PRETTY_FUNCTION__, so, sb));

    /*
     * No need to check if there's enough room to read.
     * soread wouldn't have been called if there weren't
     */

    len = sb->sb_datalen - sb->sb_cc;

    iov[0].iov_base = sb->sb_wptr;
    iov[1].iov_base = 0;
    iov[1].iov_len  = 0;
    if (sb->sb_wptr < sb->sb_rptr)
    {
        iov[0].iov_len = sb->sb_rptr - sb->sb_wptr;
        /* Should never succeed, but... */
        if (iov[0].iov_len > len)
            iov[0].iov_len = len;
        if (iov[0].iov_len > mss)
            iov[0].iov_len -= iov[0].iov_len%mss;
        n = 1;
    }
    else
    {
        iov[0].iov_len = (sb->sb_data + sb->sb_datalen) - sb->sb_wptr;
        /* Should never succeed, but... */
        if (iov[0].iov_len > len)
            iov[0].iov_len = len;
        len -= iov[0].iov_len;
        if (len)
        {
            iov[1].iov_base = sb->sb_data;
            iov[1].iov_len = sb->sb_rptr - sb->sb_data;
            if (iov[1].iov_len > len)
                iov[1].iov_len = len;
            total = iov[0].iov_len + iov[1].iov_len;
            if (total > mss)
            {
                lss = total % mss;
                if (iov[1].iov_len > lss)
                {
                    iov[1].iov_len -= lss;
                    n = 2;
                }
                else
                {
                    lss -= iov[1].iov_len;
                    iov[0].iov_len -= lss;
                    n = 1;
                }
            }
            else
                n = 2;
        }
        else
        {
            if (iov[0].iov_len > mss)
                iov[0].iov_len -= iov[0].iov_len%mss;
            n = 1;
        }
    }

#ifdef HAVE_READV
    nn = readv(so->s, (struct iovec *)iov, n);
#else
    nn = recv(so->s, iov[0].iov_base, iov[0].iov_len, (so->so_tcpcb->t_force? MSG_OOB:0));
#endif
    Log2(("%s: read(1) nn = %d bytes\n", RT_GCC_EXTENSION __PRETTY_FUNCTION__, nn));
    Log2(("%s: so = %R[natsock] so->so_snd = %R[sbuf]\n", RT_GCC_EXTENSION __PRETTY_FUNCTION__, so, sb));
    if (nn <= 0)
    {
        /*
         * Special case for WSAEnumNetworkEvents: If we receive 0 bytes that
         * _could_ mean that the connection is closed. But we will receive an
         * FD_CLOSE event later if the connection was _really_ closed. With
         * www.youtube.com I see this very often. Closing the socket too early
         * would be dangerous.
         */
        int status;
        unsigned long pending = 0;
        status = ioctlsocket(so->s, FIONREAD, &pending);
        if (status < 0)
            Log(("NAT:%s: error in WSAIoctl: %d\n", RT_GCC_EXTENSION __PRETTY_FUNCTION__, errno));
        if (nn == 0 && (pending != 0))
        {
            SOCKET_UNLOCK(so);
            STAM_PROFILE_STOP(&pData->StatIOread, a);
            return 0;
        }
        if (   nn < 0
                && soIgnorableErrorCode(errno))
        {
            SOCKET_UNLOCK(so);
            STAM_PROFILE_STOP(&pData->StatIOread, a);
            return 0;
        }
        else
        {
            int fUninitiolizedTemplate = 0;
            fUninitiolizedTemplate = RT_BOOL((   sototcpcb(so)
                                                 && (  sototcpcb(so)->t_template.ti_src.s_addr == INADDR_ANY
                                                         || sototcpcb(so)->t_template.ti_dst.s_addr == INADDR_ANY)));
            /* nn == 0 means peer has performed an orderly shutdown */
            Log2(("%s: disconnected, nn = %d, errno = %d (%s)\n",
                  RT_GCC_EXTENSION __PRETTY_FUNCTION__, nn, errno, strerror(errno)));
            sofcantrcvmore(so);
            if (!fUninitiolizedTemplate)
                tcp_sockclosed(pData, sototcpcb(so));
            else
                tcp_drop(pData, sototcpcb(so), errno);
            SOCKET_UNLOCK(so);
            STAM_PROFILE_STOP(&pData->StatIOread, a);
            return -1;
        }
    }
    STAM_STATS(
        if (n == 1)
{
    STAM_COUNTER_INC(&pData->StatIORead_in_1);
        STAM_COUNTER_ADD(&pData->StatIORead_in_1_bytes, nn);
    }
    else
    {
        STAM_COUNTER_INC(&pData->StatIORead_in_2);
        STAM_COUNTER_ADD(&pData->StatIORead_in_2_1st_bytes, nn);
    }
    );
Пример #4
0
void
tcp_timer_keep(void *xtp)
{
	struct tcpcb *tp = xtp;
	struct tcptemp *t_template;
	struct inpcb *inp;
	CURVNET_SET(tp->t_vnet);
#ifdef TCPDEBUG
	int ostate;

	ostate = tp->t_state;
#endif
	INP_INFO_WLOCK(&V_tcbinfo);
	inp = tp->t_inpcb;
	/*
	 * XXXRW: While this assert is in fact correct, bugs in the tcpcb
	 * tear-down mean we need it as a work-around for races between
	 * timers and tcp_discardcb().
	 *
	 * KASSERT(inp != NULL, ("tcp_timer_keep: inp == NULL"));
	 */
	if (inp == NULL) {
		tcp_timer_race++;
		INP_INFO_WUNLOCK(&V_tcbinfo);
		CURVNET_RESTORE();
		return;
	}
	INP_WLOCK(inp);
	if (callout_pending(&tp->t_timers->tt_keep) ||
	    !callout_active(&tp->t_timers->tt_keep)) {
		INP_WUNLOCK(inp);
		INP_INFO_WUNLOCK(&V_tcbinfo);
		CURVNET_RESTORE();
		return;
	}
	callout_deactivate(&tp->t_timers->tt_keep);
	if ((inp->inp_flags & INP_DROPPED) != 0) {
		INP_WUNLOCK(inp);
		INP_INFO_WUNLOCK(&V_tcbinfo);
		CURVNET_RESTORE();
		return;
	}
	/*
	 * Keep-alive timer went off; send something
	 * or drop connection if idle for too long.
	 */
	TCPSTAT_INC(tcps_keeptimeo);
	if (tp->t_state < TCPS_ESTABLISHED)
		goto dropit;
	if ((always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
	    tp->t_state <= TCPS_CLOSING) {
		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
			goto dropit;
		/*
		 * Send a packet designed to force a response
		 * if the peer is up and reachable:
		 * either an ACK if the connection is still alive,
		 * or an RST if the peer has closed the connection
		 * due to timeout or reboot.
		 * Using sequence number tp->snd_una-1
		 * causes the transmitted zero-length segment
		 * to lie outside the receive window;
		 * by the protocol spec, this requires the
		 * correspondent TCP to respond.
		 */
		TCPSTAT_INC(tcps_keepprobe);
		t_template = tcpip_maketemplate(inp);
		if (t_template) {
			tcp_respond(tp, t_template->tt_ipgen,
				    &t_template->tt_t, (struct mbuf *)NULL,
				    tp->rcv_nxt, tp->snd_una - 1, 0);
			free(t_template, M_TEMP);
		}
		callout_reset_on(&tp->t_timers->tt_keep, TP_KEEPINTVL(tp),
		    tcp_timer_keep, tp, INP_CPU(inp));
	} else
		callout_reset_on(&tp->t_timers->tt_keep, TP_KEEPIDLE(tp),
		    tcp_timer_keep, tp, INP_CPU(inp));

#ifdef TCPDEBUG
	if (inp->inp_socket->so_options & SO_DEBUG)
		tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
			  PRU_SLOWTIMO);
#endif
	INP_WUNLOCK(inp);
	INP_INFO_WUNLOCK(&V_tcbinfo);
	CURVNET_RESTORE();
	return;

dropit:
	TCPSTAT_INC(tcps_keepdrops);
	tp = tcp_drop(tp, ETIMEDOUT);

#ifdef TCPDEBUG
	if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
		tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
			  PRU_SLOWTIMO);
#endif
	if (tp != NULL)
		INP_WUNLOCK(tp->t_inpcb);
	INP_INFO_WUNLOCK(&V_tcbinfo);
	CURVNET_RESTORE();
}
Пример #5
0
/* Caller should be in critical section */
static struct tcpcb *
tcp_timer_keep_handler(struct tcpcb *tp)
{
	struct tcptemp *t_template;
#ifdef TCPDEBUG
	int ostate = tp->t_state;
#endif

	/*
	 * Keep-alive timer went off; send something
	 * or drop connection if idle for too long.
	 */
	tcpstat.tcps_keeptimeo++;
	if (tp->t_state < TCPS_ESTABLISHED)
		goto dropit;
	if ((always_keepalive || (tp->t_flags & TF_KEEPALIVE) ||
	     (tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE)) &&
	    tp->t_state <= TCPS_CLOSING) {
		if ((ticks - tp->t_rcvtime) >= tp->t_keepidle + tp->t_maxidle)
			goto dropit;
		/*
		 * Send a packet designed to force a response
		 * if the peer is up and reachable:
		 * either an ACK if the connection is still alive,
		 * or an RST if the peer has closed the connection
		 * due to timeout or reboot.
		 * Using sequence number tp->snd_una-1
		 * causes the transmitted zero-length segment
		 * to lie outside the receive window;
		 * by the protocol spec, this requires the
		 * correspondent TCP to respond.
		 */
		tcpstat.tcps_keepprobe++;
		t_template = tcp_maketemplate(tp);
		if (t_template) {
			tcp_respond(tp, t_template->tt_ipgen,
				    &t_template->tt_t, NULL,
				    tp->rcv_nxt, tp->snd_una - 1, 0);
			tcp_freetemplate(t_template);
		}
		tcp_callout_reset(tp, tp->tt_keep, tp->t_keepintvl,
				  tcp_timer_keep);
	} else {
		tcp_callout_reset(tp, tp->tt_keep, tp->t_keepidle,
				  tcp_timer_keep);
	}

#ifdef TCPDEBUG
	if (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)
		tcp_trace(TA_USER, ostate, tp, NULL, NULL, PRU_SLOWTIMO);
#endif
	return tp;

dropit:
	tcpstat.tcps_keepdrops++;
	tp = tcp_drop(tp, ETIMEDOUT);

#ifdef TCPDEBUG
	if (tp && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
		tcp_trace(TA_USER, ostate, tp, NULL, NULL, PRU_SLOWTIMO);
#endif
	return tp;
}