usr.sbin/timed/timed/correct.c

   1 /*-
   2  * Copyright (c) 1985, 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  * @(#)correct.c        8.1 (Berkeley) 6/6/93
  34  * $FreeBSD: src/usr.sbin/timed/timed/correct.c,v 1.4 1999/08/28 01:20:17 peter Exp $
  35  * $DragonFly: src/usr.sbin/timed/timed/correct.c,v 1.6 2004/09/05 02:09:24 dillon Exp $
  36  */
  37
  38 #include "globals.h"
  39 #include <math.h>
  40 #include <sys/types.h>
  41 #include <sys/times.h>
  42 #ifdef sgi
  43 #include <sys/syssgi.h>
  44 #endif /* sgi */
  45
  46 static void adjclock(struct timeval *);
  47
  48 /*
  49  * sends to the slaves the corrections for their clocks after fixing our
  50  * own
  51  */
  52 void
  53 correct(long avdelta)
  54 {
  55         struct hosttbl *htp;
  56         int corr;
  57         struct timeval adjlocal;
  58         struct tsp to;
  59         struct tsp *answer;
  60
  61         mstotvround(&adjlocal, avdelta);
  62
  63         for (htp = self.l_fwd; htp != &self; htp = htp->l_fwd) {
  64                 if (htp->delta != HOSTDOWN)  {
  65                         corr = avdelta - htp->delta;
  66 /* If the other machine is off in the weeds, set its time directly.
  67  *      If a slave gets the wrong day, the original code would simply
  68  *      fix the minutes.  If you fix a network partition, you can get
  69  *      into such situations.
  70  */
  71                         if (htp->need_set
  72                             || corr >= MAXADJ*1000
  73                             || corr <= -MAXADJ*1000) {
  74                                 htp->need_set = 0;
  75                                 (void)gettimeofday(&to.tsp_time,0);
  76                                 timevaladd(&to.tsp_time, &adjlocal);
  77                                 to.tsp_type = TSP_SETTIME;
  78                         } else {
  79                                 mstotvround(&to.tsp_time, corr);
  80                                 to.tsp_type = TSP_ADJTIME;
  81                         }
  82                         strlcpy(to.tsp_name, hostname, sizeof(to.tsp_name));
  83                         answer = acksend(&to, &htp->addr, htp->name,
  84                                          TSP_ACK, 0, 0);
  85                         if (!answer) {
  86                                 htp->delta = HOSTDOWN;
  87                                 syslog(LOG_WARNING,
  88                                        "no reply to time correction from %s",
  89                                        htp->name);
  90                                 if (++htp->noanswer >= LOSTHOST) {
  91                                         if (trace) {
  92                                                 fprintf(fd,
  93                                              "purging %s for not answering\n",
  94                                                         htp->name);
  95                                                 (void)fflush(fd);
  96                                         }
  97                                         htp = remmach(htp);
  98                                 }
  99                         }
 100                 }
 101         }
 102
 103         /*
 104          * adjust our own clock now that we are not sending it out
 105          */
 106         adjclock(&adjlocal);
 107 }
 108
 109
 110 static void
 111 adjclock(struct timeval *corr)
 112 {
 113         static int passes = 0;
 114         static int smoother = 0;
 115         long delta;                     /* adjustment in usec */
 116         long ndelta;
 117         struct timeval now;
 118         struct timeval adj;
 119
 120         if (!timerisset(corr))
 121                 return;
 122
 123         adj = *corr;
 124         if (adj.tv_sec < MAXADJ && adj.tv_sec > - MAXADJ) {
 125                 delta = adj.tv_sec*1000000 + adj.tv_usec;
 126                 /* If the correction is less than the minimum round
 127                  *      trip time for an ICMP packet, and thus
 128                  *      less than the likely error in the measurement,
 129                  *      do not do the entire correction.  Do half
 130                  *      or a quarter of it.
 131                  */
 132
 133                 if (delta > -MIN_ROUND*1000
 134                     && delta < MIN_ROUND*1000) {
 135                         if (smoother <= 4)
 136                                 smoother++;
 137                         ndelta = delta >> smoother;
 138                         if (trace)
 139                                 fprintf(fd,
 140                                         "trimming delta %ld usec to %ld\n",
 141                                         delta, ndelta);
 142                         adj.tv_usec = ndelta;
 143                         adj.tv_sec = 0;
 144                 } else if (smoother > 0) {
 145                         smoother--;
 146                 }
 147                 if (0 > adjtime(corr, 0)) {
 148                         syslog(LOG_ERR, "adjtime: %m");
 149                 }
 150                 if (passes > 1
 151                     && (delta < -BIG_ADJ || delta > BIG_ADJ)) {
 152                         smoother = 0;
 153                         passes = 0;
 154                         syslog(LOG_WARNING,
 155                                "large time adjustment of %+.3f sec",
 156                                delta/1000000.0);
 157                 }
 158         } else {
 159                 syslog(LOG_WARNING,
 160                        "clock correction %ld sec too large to adjust",
 161                        adj.tv_sec);
 162                 (void) gettimeofday(&now, 0);
 163                 timevaladd(&now, corr);
 164                 if (settimeofday(&now, 0) < 0)
 165                         syslog(LOG_ERR, "settimeofday: %m");
 166         }
 167
 168 #ifdef sgi
 169         /* Accumulate the total change, and use it to adjust the basic
 170          * clock rate.
 171          */
 172         if (++passes > 2) {
 173 #define F_USEC_PER_SEC  (1000000*1.0)   /* reduce typos */
 174 #define F_NSEC_PER_SEC  (F_USEC_PER_SEC*1000.0)
 175
 176                 extern char *timetrim_fn;
 177                 extern char *timetrim_wpat;
 178                 extern long timetrim;
 179                 extern double tot_adj, hr_adj;  /* totals in nsec */
 180                 extern double tot_ticks, hr_ticks;
 181
 182                 static double nag_tick;
 183                 double cur_ticks, hr_delta_ticks, tot_delta_ticks;
 184                 double tru_tot_adj, tru_hr_adj; /* nsecs of adjustment */
 185                 double tot_trim, hr_trim;   /* nsec/sec */
 186                 struct tms tm;
 187                 FILE *timetrim_st;
 188
 189                 cur_ticks = times(&tm);
 190                 tot_adj += delta*1000.0;
 191                 hr_adj += delta*1000.0;
 192
 193                 tot_delta_ticks = cur_ticks-tot_ticks;
 194                 if (tot_delta_ticks >= 16*SECDAY*CLK_TCK) {
 195                         tot_adj -= rint(tot_adj/16);
 196                         tot_ticks += rint(tot_delta_ticks/16);
 197                         tot_delta_ticks = cur_ticks-tot_ticks;
 198                 }
 199                 hr_delta_ticks = cur_ticks-hr_ticks;
 200
 201                 tru_hr_adj = hr_adj + timetrim*rint(hr_delta_ticks/CLK_TCK);
 202                 tru_tot_adj = (tot_adj
 203                                + timetrim*rint(tot_delta_ticks/CLK_TCK));
 204
 205                 if (hr_delta_ticks >= SECDAY*CLK_TCK
 206                     || (tot_delta_ticks < 4*SECDAY*CLK_TCK
 207                         && hr_delta_ticks >= SECHR*CLK_TCK)
 208                     || (trace && hr_delta_ticks >= (SECHR/10)*CLK_TCK)) {
 209
 210                         tot_trim = rint(tru_tot_adj*CLK_TCK/tot_delta_ticks);
 211                         hr_trim = rint(tru_hr_adj*CLK_TCK/hr_delta_ticks);
 212
 213                         if (trace
 214                             || (abs(timetrim - hr_trim) > 100000.0
 215                                 && 0 == timetrim_fn
 216                                 && ((cur_ticks - nag_tick)
 217                                     >= 24*SECDAY*CLK_TCK))) {
 218                                 nag_tick = cur_ticks;
 219                                 syslog(LOG_NOTICE,
 220                    "%+.3f/%.2f or %+.3f/%.2f sec/hr; timetrim=%+.0f or %+.0f",
 221                                        tru_tot_adj/F_NSEC_PER_SEC,
 222                                        tot_delta_ticks/(SECHR*CLK_TCK*1.0),
 223                                        tru_hr_adj/F_NSEC_PER_SEC,
 224                                        hr_delta_ticks/(SECHR*CLK_TCK*1.0),
 225                                        tot_trim,
 226                                        hr_trim);
 227                         }
 228
 229                         if (tot_trim < -MAX_TRIM || tot_trim > MAX_TRIM) {
 230                                 tot_ticks = hr_ticks;
 231                                 tot_adj = hr_adj;
 232                         } else if (0 > syssgi(SGI_SETTIMETRIM,
 233                                               (long)tot_trim)) {
 234                                 syslog(LOG_ERR, "SETTIMETRIM(%d): %m",
 235                                        (long)tot_trim);
 236                         } else {
 237                                 if (0 != timetrim_fn) {
 238                                     timetrim_st = fopen(timetrim_fn, "w");
 239                                     if (0 == timetrim_st) {
 240                                         syslog(LOG_ERR, "fopen(%s): %m",
 241                                                timetrim_fn);
 242                                     } else {
 243                                         if (0 > fprintf(timetrim_st,
 244                                                         timetrim_wpat,
 245                                                         (long)tot_trim,
 246                                                         tru_tot_adj,
 247                                                         tot_delta_ticks)) {
 248                                                 syslog(LOG_ERR,
 249                                                        "fprintf(%s): %m",
 250                                                        timetrim_fn);
 251                                         }
 252                                         (void)fclose(timetrim_st);
 253                                     }
 254                                 }
 255
 256                                 tot_adj -= ((tot_trim - timetrim)
 257                                             * rint(tot_delta_ticks/CLK_TCK));
 258                                 timetrim = tot_trim;
 259                         }
 260
 261                         hr_ticks = cur_ticks;
 262                         hr_adj = 0;
 263                 }
 264         }
 265 #endif /* sgi */
 266 }
 267
 268
 269 /* adjust the time in a message by the time it
 270  *      spent in the queue
 271  */
 272 void
 273 adj_msg_time(struct tsp *msg, struct timeval *now)
 274 {
 275         msg->tsp_time.tv_sec += (now->tv_sec - from_when.tv_sec);
 276         msg->tsp_time.tv_usec += (now->tv_usec - from_when.tv_usec);
 277
 278         while (msg->tsp_time.tv_usec < 0) {
 279                 msg->tsp_time.tv_sec--;
 280                 msg->tsp_time.tv_usec += 1000000;
 281         }
 282         while (msg->tsp_time.tv_usec >= 1000000) {
 283                 msg->tsp_time.tv_sec++;
 284                 msg->tsp_time.tv_usec -= 1000000;
 285         }
 286 }