src/slirp/tcp_timer.c

/*
 * Copyright (c) 1982, 1986, 1988, 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)tcp_timer.c 8.1 (Berkeley) 6/10/93
 * tcp_timer.c,v 1.2 1994/08/02 07:49:10 davidg Exp
 */

#include <slirp.h>

int     tcp_keepidle = TCPTV_KEEP_IDLE;
int     tcp_keepintvl = TCPTV_KEEPINTVL;
int     tcp_maxidle;
int     so_options = DO_KEEPALIVE;

struct   tcpstat tcpstat;        /* tcp statistics */
u_int32_t        tcp_now;                /* for RFC 1323 timestamps */

/*
 * Fast timeout routine for processing delayed acks
 */
void
tcp_fasttimo()
{
        register struct socket *so;
        register struct tcpcb *tp;

        DEBUG_CALL("tcp_fasttimo");
        
        so = tcb.so_next;
        if (so)
        for (; so != &tcb; so = so->so_next)
                if ((tp = (struct tcpcb *)so->so_tcpcb) &&
                    (tp->t_flags & TF_DELACK)) {
                        tp->t_flags &= ~TF_DELACK;
                        tp->t_flags |= TF_ACKNOW;
                        tcpstat.tcps_delack++;
                        (void) tcp_output(tp);
                }
}

/*
 * Tcp protocol timeout routine called every 500 ms.
 * Updates the timers in all active tcb's and
 * causes finite state machine actions if timers expire.
 */
void
tcp_slowtimo()
{
        register struct socket *ip, *ipnxt;
        register struct tcpcb *tp;
        register int i;

        DEBUG_CALL("tcp_slowtimo");
        
        tcp_maxidle = TCPTV_KEEPCNT * tcp_keepintvl;
        /*
         * Search through tcb's and update active timers.
         */
        ip = tcb.so_next;
        if (ip == 0)
           return;
        for (; ip != &tcb; ip = ipnxt) {
                ipnxt = ip->so_next;
                tp = sototcpcb(ip);
                if (tp == 0)
                        continue;
                for (i = 0; i < TCPT_NTIMERS; i++) {
                        if (tp->t_timer[i] && --tp->t_timer[i] == 0) {
                                tcp_timers(tp,i);
                                if (ipnxt->so_prev != ip)
                                        goto tpgone;
                        }
                }
                tp->t_idle++;
                if (tp->t_rtt)
                   tp->t_rtt++;
tpgone:
                ;
        }
        tcp_iss += TCP_ISSINCR/PR_SLOWHZ;               /* increment iss */
#ifdef TCP_COMPAT_42
        if ((int)tcp_iss < 0)
                tcp_iss = 0;                            /* XXX */
#endif
        tcp_now++;                                      /* for timestamps */
}

/*
 * Cancel all timers for TCP tp.
 */
void
tcp_canceltimers(tp)
        struct tcpcb *tp;
{
        register int i;

        for (i = 0; i < TCPT_NTIMERS; i++)
                tp->t_timer[i] = 0;
}

int     tcp_backoff[TCP_MAXRXTSHIFT + 1] =
   { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };

/*
 * TCP timer processing.
 */
struct tcpcb *
tcp_timers(tp, timer)
        register struct tcpcb *tp;
        int timer;
{
        register int rexmt;
        
        DEBUG_CALL("tcp_timers");
        
        switch (timer) {

        /*
         * 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, or if 2MSL time is up from TIME_WAIT, delete connection
         * control block.  Otherwise, check again in a bit.
         */
        case TCPT_2MSL:
                if (tp->t_state != TCPS_TIME_WAIT &&
                    tp->t_idle <= tcp_maxidle)
                        tp->t_timer[TCPT_2MSL] = tcp_keepintvl;
                else
                        tp = tcp_close(tp);
                break;

        /*
         * Retransmission timer went off.  Message has not
         * been acked within retransmit interval.  Back off
         * to a longer retransmit interval and retransmit one segment.
         */
        case TCPT_REXMT:
                
                /*
                 * XXXXX If a packet has timed out, then remove all the queued
                 * packets for that session.
                 */
                
                if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) {
                        /*
                         * This is a hack to suit our terminal server here at the uni of canberra
                         * since they have trouble with zeroes... It usually lets them through
                         * unharmed, but under some conditions, it'll eat the zeros.  If we
                         * keep retransmitting it, it'll keep eating the zeroes, so we keep
                         * retransmitting, and eventually the connection dies...
                         * (this only happens on incoming data)
                         * 
                         * So, if we were gonna drop the connection from too many retransmits,
                         * don't... instead halve the t_maxseg, which might break up the NULLs and
                         * let them through
                         * 
                         * *sigh*
                         */
                        
                        tp->t_maxseg >>= 1;
                        if (tp->t_maxseg < 32) {
                                /*
                                 * We tried our best, now the connection must die!
                                 */
                                tp->t_rxtshift = TCP_MAXRXTSHIFT;
                                tcpstat.tcps_timeoutdrop++;
                                tp = tcp_drop(tp, tp->t_softerror);
                                /* tp->t_softerror : ETIMEDOUT); */ /* XXX */
                                return (tp); /* XXX */
                        }
                        
                        /*
                         * Set rxtshift to 6, which is still at the maximum
                         * backoff time
                         */
                        tp->t_rxtshift = 6;
                }
                tcpstat.tcps_rexmttimeo++;
                rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
                TCPT_RANGESET(tp->t_rxtcur, rexmt,
                    (short)tp->t_rttmin, TCPTV_REXMTMAX); /* XXX */
                tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
                /*
                 * If losing, let the lower level know and try for
                 * a better route.  Also, if we backed off this far,
                 * our srtt estimate is probably bogus.  Clobber it
                 * so we'll take the next rtt measurement as our srtt;
                 * move the current srtt into rttvar to keep the current
                 * retransmit times until then.
                 */
                if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
/*                      in_losing(tp->t_inpcb); */
                        tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
                        tp->t_srtt = 0;
                }
                tp->snd_nxt = tp->snd_una;
                /*
                 * If timing a segment in this window, stop the timer.
                 */
                tp->t_rtt = 0;
                /*
                 * Close the congestion window down to one segment
                 * (we'll open it by one segment for each ack we get).
                 * Since we probably have a window's worth of unacked
                 * data accumulated, this "slow start" keeps us from
                 * dumping all that data as back-to-back packets (which
                 * might overwhelm an intermediate gateway).
                 *
                 * There are two phases to the opening: Initially we
                 * open by one mss on each ack.  This makes the window
                 * size increase exponentially with time.  If the
                 * window is larger than the path can handle, this
                 * exponential growth results in dropped packet(s)
                 * almost immediately.  To get more time between 
                 * drops but still "push" the network to take advantage
                 * of improving conditions, we switch from exponential
                 * to linear window opening at some threshold size.
                 * For a threshold, we use half the current window
                 * size, truncated to a multiple of the mss.
                 *
                 * (the minimum cwnd that will give us exponential
                 * growth is 2 mss.  We don't allow the threshold
                 * to go below this.)
                 */
                {
                u_int win = min(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_maxseg;
                if (win < 2)
                        win = 2;
                tp->snd_cwnd = tp->t_maxseg;
                tp->snd_ssthresh = win * tp->t_maxseg;
                tp->t_dupacks = 0;
                }
                (void) tcp_output(tp);
                break;

        /*
         * Persistence timer into zero window.
         * Force a byte to be output, if possible.
         */
        case TCPT_PERSIST:
                tcpstat.tcps_persisttimeo++;
                tcp_setpersist(tp);
                tp->t_force = 1;
                (void) tcp_output(tp);
                tp->t_force = 0;
                break;

        /*
         * Keep-alive timer went off; send something
         * or drop connection if idle for too long.
         */
        case TCPT_KEEP:
                tcpstat.tcps_keeptimeo++;
                if (tp->t_state < TCPS_ESTABLISHED)
                        goto dropit;

/*              if (tp->t_socket->so_options & SO_KEEPALIVE && */
                if ((so_options) && tp->t_state <= TCPS_CLOSE_WAIT) {
                        if (tp->t_idle >= tcp_keepidle + tcp_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++;
#ifdef TCP_COMPAT_42
                        /*
                         * The keepalive packet must have nonzero length
                         * to get a 4.2 host to respond.
                         */
                        tcp_respond(tp, &tp->t_template, (struct mbuf *)NULL,
                            tp->rcv_nxt - 1, tp->snd_una - 1, 0);
#else
                        tcp_respond(tp, &tp->t_template, (struct mbuf *)NULL,
                            tp->rcv_nxt, tp->snd_una - 1, 0);
#endif
                        tp->t_timer[TCPT_KEEP] = tcp_keepintvl;
                } else
                        tp->t_timer[TCPT_KEEP] = tcp_keepidle;
                break;

        dropit:
                tcpstat.tcps_keepdrops++;
                tp = tcp_drop(tp, 0); /* ETIMEDOUT); */
                break;
        }

        return (tp);
}
Revision:	1.1
Committed:	2005-05-13T09:00:59Z (19 years, 6 months ago) by gbeauche
Content type:	text/plain
Branch:	MAIN
CVS Tags:	nigel-build-19, nigel-build-17
Log Message:	slirp user mode network emulation code from qemu
#	User	Rev	Content
1	gbeauche	1.1	/*
2			* Copyright (c) 1982, 1986, 1988, 1990, 1993
3			* The Regents of the University of California. All rights reserved.
4			*
5			* Redistribution and use in source and binary forms, with or without
6			* modification, are permitted provided that the following conditions
7			* are met:
8			* 1. Redistributions of source code must retain the above copyright
9			* notice, this list of conditions and the following disclaimer.
10			* 2. Redistributions in binary form must reproduce the above copyright
11			* notice, this list of conditions and the following disclaimer in the
12			* documentation and/or other materials provided with the distribution.
13			* 3. All advertising materials mentioning features or use of this software
14			* must display the following acknowledgement:
15			* This product includes software developed by the University of
16			* California, Berkeley and its contributors.
17			* 4. Neither the name of the University nor the names of its contributors
18			* may be used to endorse or promote products derived from this software
19			* without specific prior written permission.
20			*
21			* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22			* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23			* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24			* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25			* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26			* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27			* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28			* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29			* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30			* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31			* SUCH DAMAGE.
32			*
33			* @(#)tcp_timer.c 8.1 (Berkeley) 6/10/93
34			* tcp_timer.c,v 1.2 1994/08/02 07:49:10 davidg Exp
35			*/
36
37			#include <slirp.h>
38
39			int tcp_keepidle = TCPTV_KEEP_IDLE;
40			int tcp_keepintvl = TCPTV_KEEPINTVL;
41			int tcp_maxidle;
42			int so_options = DO_KEEPALIVE;
43
44			struct tcpstat tcpstat; /* tcp statistics */
45			u_int32_t tcp_now; /* for RFC 1323 timestamps */
46
47			/*
48			* Fast timeout routine for processing delayed acks
49			*/
50			void
51			tcp_fasttimo()
52			{
53			register struct socket *so;
54			register struct tcpcb *tp;
55
56			DEBUG_CALL("tcp_fasttimo");
57
58			so = tcb.so_next;
59			if (so)
60			for (; so != &tcb; so = so->so_next)
61			if ((tp = (struct tcpcb *)so->so_tcpcb) &&
62			(tp->t_flags & TF_DELACK)) {
63			tp->t_flags &= ~TF_DELACK;
64			tp->t_flags \|= TF_ACKNOW;
65			tcpstat.tcps_delack++;
66			(void) tcp_output(tp);
67			}
68			}
69
70			/*
71			* Tcp protocol timeout routine called every 500 ms.
72			* Updates the timers in all active tcb's and
73			* causes finite state machine actions if timers expire.
74			*/
75			void
76			tcp_slowtimo()
77			{
78			register struct socket ip, ipnxt;
79			register struct tcpcb *tp;
80			register int i;
81
82			DEBUG_CALL("tcp_slowtimo");
83
84			tcp_maxidle = TCPTV_KEEPCNT * tcp_keepintvl;
85			/*
86			* Search through tcb's and update active timers.
87			*/
88			ip = tcb.so_next;
89			if (ip == 0)
90			return;
91			for (; ip != &tcb; ip = ipnxt) {
92			ipnxt = ip->so_next;
93			tp = sototcpcb(ip);
94			if (tp == 0)
95			continue;
96			for (i = 0; i < TCPT_NTIMERS; i++) {
97			if (tp->t_timer[i] && --tp->t_timer[i] == 0) {
98			tcp_timers(tp,i);
99			if (ipnxt->so_prev != ip)
100			goto tpgone;
101			}
102			}
103			tp->t_idle++;
104			if (tp->t_rtt)
105			tp->t_rtt++;
106			tpgone:
107			;
108			}
109			tcp_iss += TCP_ISSINCR/PR_SLOWHZ; /* increment iss */
110			#ifdef TCP_COMPAT_42
111			if ((int)tcp_iss < 0)
112			tcp_iss = 0; /* XXX */
113			#endif
114			tcp_now++; /* for timestamps */
115			}
116
117			/*
118			* Cancel all timers for TCP tp.
119			*/
120			void
121			tcp_canceltimers(tp)
122			struct tcpcb *tp;
123			{
124			register int i;
125
126			for (i = 0; i < TCPT_NTIMERS; i++)
127			tp->t_timer[i] = 0;
128			}
129
130			int tcp_backoff[TCP_MAXRXTSHIFT + 1] =
131			{ 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
132
133			/*
134			* TCP timer processing.
135			*/
136			struct tcpcb *
137			tcp_timers(tp, timer)
138			register struct tcpcb *tp;
139			int timer;
140			{
141			register int rexmt;
142
143			DEBUG_CALL("tcp_timers");
144
145			switch (timer) {
146
147			/*
148			* 2 MSL timeout in shutdown went off. If we're closed but
149			* still waiting for peer to close and connection has been idle
150			* too long, or if 2MSL time is up from TIME_WAIT, delete connection
151			* control block. Otherwise, check again in a bit.
152			*/
153			case TCPT_2MSL:
154			if (tp->t_state != TCPS_TIME_WAIT &&
155			tp->t_idle <= tcp_maxidle)
156			tp->t_timer[TCPT_2MSL] = tcp_keepintvl;
157			else
158			tp = tcp_close(tp);
159			break;
160
161			/*
162			* Retransmission timer went off. Message has not
163			* been acked within retransmit interval. Back off
164			* to a longer retransmit interval and retransmit one segment.
165			*/
166			case TCPT_REXMT:
167
168			/*
169			* XXXXX If a packet has timed out, then remove all the queued
170			* packets for that session.
171			*/
172
173			if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) {
174			/*
175			* This is a hack to suit our terminal server here at the uni of canberra
176			* since they have trouble with zeroes... It usually lets them through
177			* unharmed, but under some conditions, it'll eat the zeros. If we
178			* keep retransmitting it, it'll keep eating the zeroes, so we keep
179			* retransmitting, and eventually the connection dies...
180			* (this only happens on incoming data)
181			*
182			* So, if we were gonna drop the connection from too many retransmits,
183			* don't... instead halve the t_maxseg, which might break up the NULLs and
184			* let them through
185			*
186			* sigh
187			*/
188
189			tp->t_maxseg >>= 1;
190			if (tp->t_maxseg < 32) {
191			/*
192			* We tried our best, now the connection must die!
193			*/
194			tp->t_rxtshift = TCP_MAXRXTSHIFT;
195			tcpstat.tcps_timeoutdrop++;
196			tp = tcp_drop(tp, tp->t_softerror);
197			/* tp->t_softerror : ETIMEDOUT); / / XXX */
198			return (tp); /* XXX */
199			}
200
201			/*
202			* Set rxtshift to 6, which is still at the maximum
203			* backoff time
204			*/
205			tp->t_rxtshift = 6;
206			}
207			tcpstat.tcps_rexmttimeo++;
208			rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
209			TCPT_RANGESET(tp->t_rxtcur, rexmt,
210			(short)tp->t_rttmin, TCPTV_REXMTMAX); /* XXX */
211			tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
212			/*
213			* If losing, let the lower level know and try for
214			* a better route. Also, if we backed off this far,
215			* our srtt estimate is probably bogus. Clobber it
216			* so we'll take the next rtt measurement as our srtt;
217			* move the current srtt into rttvar to keep the current
218			* retransmit times until then.
219			*/
220			if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
221			/* in_losing(tp->t_inpcb); */
222			tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
223			tp->t_srtt = 0;
224			}
225			tp->snd_nxt = tp->snd_una;
226			/*
227			* If timing a segment in this window, stop the timer.
228			*/
229			tp->t_rtt = 0;
230			/*
231			* Close the congestion window down to one segment
232			* (we'll open it by one segment for each ack we get).
233			* Since we probably have a window's worth of unacked
234			* data accumulated, this "slow start" keeps us from
235			* dumping all that data as back-to-back packets (which
236			* might overwhelm an intermediate gateway).
237			*
238			* There are two phases to the opening: Initially we
239			* open by one mss on each ack. This makes the window
240			* size increase exponentially with time. If the
241			* window is larger than the path can handle, this
242			* exponential growth results in dropped packet(s)
243			* almost immediately. To get more time between
244			* drops but still "push" the network to take advantage
245			* of improving conditions, we switch from exponential
246			* to linear window opening at some threshold size.
247			* For a threshold, we use half the current window
248			* size, truncated to a multiple of the mss.
249			*
250			* (the minimum cwnd that will give us exponential
251			* growth is 2 mss. We don't allow the threshold
252			* to go below this.)
253			*/
254			{
255			u_int win = min(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_maxseg;
256			if (win < 2)
257			win = 2;
258			tp->snd_cwnd = tp->t_maxseg;
259			tp->snd_ssthresh = win * tp->t_maxseg;
260			tp->t_dupacks = 0;
261			}
262			(void) tcp_output(tp);
263			break;
264
265			/*
266			* Persistence timer into zero window.
267			* Force a byte to be output, if possible.
268			*/
269			case TCPT_PERSIST:
270			tcpstat.tcps_persisttimeo++;
271			tcp_setpersist(tp);
272			tp->t_force = 1;
273			(void) tcp_output(tp);
274			tp->t_force = 0;
275			break;
276
277			/*
278			* Keep-alive timer went off; send something
279			* or drop connection if idle for too long.
280			*/
281			case TCPT_KEEP:
282			tcpstat.tcps_keeptimeo++;
283			if (tp->t_state < TCPS_ESTABLISHED)
284			goto dropit;
285
286			/* if (tp->t_socket->so_options & SO_KEEPALIVE && */
287			if ((so_options) && tp->t_state <= TCPS_CLOSE_WAIT) {
288			if (tp->t_idle >= tcp_keepidle + tcp_maxidle)
289			goto dropit;
290			/*
291			* Send a packet designed to force a response
292			* if the peer is up and reachable:
293			* either an ACK if the connection is still alive,
294			* or an RST if the peer has closed the connection
295			* due to timeout or reboot.
296			* Using sequence number tp->snd_una-1
297			* causes the transmitted zero-length segment
298			* to lie outside the receive window;
299			* by the protocol spec, this requires the
300			* correspondent TCP to respond.
301			*/
302			tcpstat.tcps_keepprobe++;
303			#ifdef TCP_COMPAT_42
304			/*
305			* The keepalive packet must have nonzero length
306			* to get a 4.2 host to respond.
307			*/
308			tcp_respond(tp, &tp->t_template, (struct mbuf *)NULL,
309			tp->rcv_nxt - 1, tp->snd_una - 1, 0);
310			#else
311			tcp_respond(tp, &tp->t_template, (struct mbuf *)NULL,
312			tp->rcv_nxt, tp->snd_una - 1, 0);
313			#endif
314			tp->t_timer[TCPT_KEEP] = tcp_keepintvl;
315			} else
316			tp->t_timer[TCPT_KEEP] = tcp_keepidle;
317			break;
318
319			dropit:
320			tcpstat.tcps_keepdrops++;
321			tp = tcp_drop(tp, 0); /* ETIMEDOUT); */
322			break;
323			}
324
325			return (tp);
326			}