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
  34 #ifndef lint
  35 #if 0
  36 static char sccsid[] = "@(#)correct.c   8.1 (Berkeley) 6/6/93";
  37 #endif
  38 static const char rcsid[] =
  39   "$FreeBSD: src/usr.sbin/timed/timed/correct.c,v 1.4 1999/08/28 01:20:17 peter Exp $";
  40 #endif /* not lint */
  41
  42 #include "globals.h"
  43 #include <math.h>
  44 #include <sys/types.h>
  45 #include <sys/times.h>
  46 #ifdef sgi
  47 #include <sys/syssgi.h>
  48 #endif /* sgi */
  49
  50 static void adjclock __P((struct timeval *));
  51
  52 /*
  53  * sends to the slaves the corrections for their clocks after fixing our
  54  * own
  55  */
  56 void
  57 correct(avdelta)
  58         long avdelta;
  59 {
  60         struct hosttbl *htp;
  61         int corr;
  62         struct timeval adjlocal;
  63         struct tsp to;
  64         struct tsp *answer;
  65
  66         mstotvround(&adjlocal, avdelta);
  67
  68         for (htp = self.l_fwd; htp != &self; htp = htp->l_fwd) {
  69                 if (htp->delta != HOSTDOWN)  {
  70                         corr = avdelta - htp->delta;
  71 /* If the other machine is off in the weeds, set its time directly.
  72  *      If a slave gets the wrong day, the original code would simply
  73  *      fix the minutes.  If you fix a network partition, you can get
  74  *      into such situations.
  75  */
  76                         if (htp->need_set
  77                             || corr >= MAXADJ*1000
  78                             || corr <= -MAXADJ*1000) {
  79                                 htp->need_set = 0;
  80                                 (void)gettimeofday(&to.tsp_time,0);
  81                                 timevaladd(&to.tsp_time, &adjlocal);
  82                                 to.tsp_type = TSP_SETTIME;
  83                         } else {
  84                                 mstotvround(&to.tsp_time, corr);
  85                                 to.tsp_type = TSP_ADJTIME;
  86                         }
  87                         (void)strcpy(to.tsp_name, hostname);
  88                         answer = acksend(&to, &htp->addr, htp->name,
  89                                          TSP_ACK, 0, 0);
  90                         if (!answer) {
  91                                 htp->delta = HOSTDOWN;
  92                                 syslog(LOG_WARNING,
  93                                        "no reply to time correction from %s",
  94                                        htp->name);
  95                                 if (++htp->noanswer >= LOSTHOST) {
  96                                         if (trace) {
  97                                                 fprintf(fd,
  98                                              "purging %s for not answering\n",
  99                                                         htp->name);
 100                                                 (void)fflush(fd);
 101                                         }
 102                                         htp = remmach(htp);
 103                                 }
 104                         }
 105                 }
 106         }
 107
 108         /*
 109          * adjust our own clock now that we are not sending it out
 110          */
 111         adjclock(&adjlocal);
 112 }
 113
 114
 115 static void
 116 adjclock(corr)
 117         struct timeval *corr;
 118 {
 119         static int passes = 0;
 120         static int smoother = 0;
 121         long delta;                     /* adjustment in usec */
 122         long ndelta;
 123         struct timeval now;
 124         struct timeval adj;
 125
 126         if (!timerisset(corr))
 127                 return;
 128
 129         adj = *corr;
 130         if (adj.tv_sec < MAXADJ && adj.tv_sec > - MAXADJ) {
 131                 delta = adj.tv_sec*1000000 + adj.tv_usec;
 132                 /* If the correction is less than the minimum round
 133                  *      trip time for an ICMP packet, and thus
 134                  *      less than the likely error in the measurement,
 135                  *      do not do the entire correction.  Do half
 136                  *      or a quarter of it.
 137                  */
 138
 139                 if (delta > -MIN_ROUND*1000
 140                     && delta < MIN_ROUND*1000) {
 141                         if (smoother <= 4)
 142                                 smoother++;
 143                         ndelta = delta >> smoother;
 144                         if (trace)
 145                                 fprintf(fd,
 146                                         "trimming delta %ld usec to %ld\n",
 147                                         delta, ndelta);
 148                         adj.tv_usec = ndelta;
 149                         adj.tv_sec = 0;
 150                 } else if (smoother > 0) {
 151                         smoother--;
 152                 }
 153                 if (0 > adjtime(corr, 0)) {
 154                         syslog(LOG_ERR, "adjtime: %m");
 155                 }
 156                 if (passes > 1
 157                     && (delta < -BIG_ADJ || delta > BIG_ADJ)) {
 158                         smoother = 0;
 159                         passes = 0;
 160                         syslog(LOG_WARNING,
 161                                "large time adjustment of %+.3f sec",
 162                                delta/1000000.0);
 163                 }
 164         } else {
 165                 syslog(LOG_WARNING,
 166                        "clock correction %d sec too large to adjust",
 167                        adj.tv_sec);
 168                 (void) gettimeofday(&now, 0);
 169                 timevaladd(&now, corr);
 170                 if (settimeofday(&now, 0) < 0)
 171                         syslog(LOG_ERR, "settimeofday: %m");
 172         }
 173
 174 #ifdef sgi
 175         /* Accumulate the total change, and use it to adjust the basic
 176          * clock rate.
 177          */
 178         if (++passes > 2) {
 179 #define F_USEC_PER_SEC  (1000000*1.0)   /* reduce typos */
 180 #define F_NSEC_PER_SEC  (F_USEC_PER_SEC*1000.0)
 181
 182                 extern char *timetrim_fn;
 183                 extern char *timetrim_wpat;
 184                 extern long timetrim;
 185                 extern double tot_adj, hr_adj;  /* totals in nsec */
 186                 extern double tot_ticks, hr_ticks;
 187
 188                 static double nag_tick;
 189                 double cur_ticks, hr_delta_ticks, tot_delta_ticks;
 190                 double tru_tot_adj, tru_hr_adj; /* nsecs of adjustment */
 191                 double tot_trim, hr_trim;   /* nsec/sec */
 192                 struct tms tm;
 193                 FILE *timetrim_st;
 194
 195                 cur_ticks = times(&tm);
 196                 tot_adj += delta*1000.0;
 197                 hr_adj += delta*1000.0;
 198
 199                 tot_delta_ticks = cur_ticks-tot_ticks;
 200                 if (tot_delta_ticks >= 16*SECDAY*CLK_TCK) {
 201                         tot_adj -= rint(tot_adj/16);
 202                         tot_ticks += rint(tot_delta_ticks/16);
 203                         tot_delta_ticks = cur_ticks-tot_ticks;
 204                 }
 205                 hr_delta_ticks = cur_ticks-hr_ticks;
 206
 207                 tru_hr_adj = hr_adj + timetrim*rint(hr_delta_ticks/CLK_TCK);
 208                 tru_tot_adj = (tot_adj
 209                                + timetrim*rint(tot_delta_ticks/CLK_TCK));
 210
 211                 if (hr_delta_ticks >= SECDAY*CLK_TCK
 212                     || (tot_delta_ticks < 4*SECDAY*CLK_TCK
 213                         && hr_delta_ticks >= SECHR*CLK_TCK)
 214                     || (trace && hr_delta_ticks >= (SECHR/10)*CLK_TCK)) {
 215
 216                         tot_trim = rint(tru_tot_adj*CLK_TCK/tot_delta_ticks);
 217                         hr_trim = rint(tru_hr_adj*CLK_TCK/hr_delta_ticks);
 218
 219                         if (trace
 220                             || (abs(timetrim - hr_trim) > 100000.0
 221                                 && 0 == timetrim_fn
 222                                 && ((cur_ticks - nag_tick)
 223                                     >= 24*SECDAY*CLK_TCK))) {
 224                                 nag_tick = cur_ticks;
 225                                 syslog(LOG_NOTICE,
 226                    "%+.3f/%.2f or %+.3f/%.2f sec/hr; timetrim=%+.0f or %+.0f",
 227                                        tru_tot_adj/F_NSEC_PER_SEC,
 228                                        tot_delta_ticks/(SECHR*CLK_TCK*1.0),
 229                                        tru_hr_adj/F_NSEC_PER_SEC,
 230                                        hr_delta_ticks/(SECHR*CLK_TCK*1.0),
 231                                        tot_trim,
 232                                        hr_trim);
 233                         }
 234
 235                         if (tot_trim < -MAX_TRIM || tot_trim > MAX_TRIM) {
 236                                 tot_ticks = hr_ticks;
 237                                 tot_adj = hr_adj;
 238                         } else if (0 > syssgi(SGI_SETTIMETRIM,
 239                                               (long)tot_trim)) {
 240                                 syslog(LOG_ERR, "SETTIMETRIM(%d): %m",
 241                                        (long)tot_trim);
 242                         } else {
 243                                 if (0 != timetrim_fn) {
 244                                     timetrim_st = fopen(timetrim_fn, "w");
 245                                     if (0 == timetrim_st) {
 246                                         syslog(LOG_ERR, "fopen(%s): %m",
 247                                                timetrim_fn);
 248                                     } else {
 249                                         if (0 > fprintf(timetrim_st,
 250                                                         timetrim_wpat,
 251                                                         (long)tot_trim,
 252                                                         tru_tot_adj,
 253                                                         tot_delta_ticks)) {
 254                                                 syslog(LOG_ERR,
 255                                                        "fprintf(%s): %m",
 256                                                        timetrim_fn);
 257                                         }
 258                                         (void)fclose(timetrim_st);
 259                                     }
 260                                 }
 261
 262                                 tot_adj -= ((tot_trim - timetrim)
 263                                             * rint(tot_delta_ticks/CLK_TCK));
 264                                 timetrim = tot_trim;
 265                         }
 266
 267                         hr_ticks = cur_ticks;
 268                         hr_adj = 0;
 269                 }
 270         }
 271 #endif /* sgi */
 272 }
 273
 274
 275 /* adjust the time in a message by the time it
 276  *      spent in the queue
 277  */
 278 void
 279 adj_msg_time(msg, now)
 280         struct tsp *msg;
 281         struct timeval *now;
 282 {
 283         msg->tsp_time.tv_sec += (now->tv_sec - from_when.tv_sec);
 284         msg->tsp_time.tv_usec += (now->tv_usec - from_when.tv_usec);
 285
 286         while (msg->tsp_time.tv_usec < 0) {
 287                 msg->tsp_time.tv_sec--;
 288                 msg->tsp_time.tv_usec += 1000000;
 289         }
 290         while (msg->tsp_time.tv_usec >= 1000000) {
 291                 msg->tsp_time.tv_sec++;
 292                 msg->tsp_time.tv_usec -= 1000000;
 293         }
 294 }