2 * Copyright (c) 1985, 1993
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32 static char sccsid[] = "@(#)correct.c 8.1 (Berkeley) 6/6/93";
34 static const char rcsid[] =
40 #include <sys/types.h>
41 #include <sys/times.h>
43 static void adjclock(struct timeval *);
46 * sends to the slaves the corrections for their clocks after fixing our
55 struct timeval adjlocal, tmptv;
59 mstotvround(&adjlocal, avdelta);
61 for (htp = self.l_fwd; htp != &self; htp = htp->l_fwd) {
62 if (htp->delta != HOSTDOWN) {
63 corr = avdelta - htp->delta;
64 /* If the other machine is off in the weeds, set its time directly.
65 * If a slave gets the wrong day, the original code would simply
66 * fix the minutes. If you fix a network partition, you can get
67 * into such situations.
70 || corr >= MAXADJ*1000
71 || corr <= -MAXADJ*1000) {
73 (void)gettimeofday(&tmptv,0);
74 timevaladd(&tmptv, &adjlocal);
75 to.tsp_time.tv_sec = tmptv.tv_sec;
76 to.tsp_time.tv_usec = tmptv.tv_usec;
77 to.tsp_type = TSP_SETTIME;
79 tmptv.tv_sec = to.tsp_time.tv_sec;
80 tmptv.tv_usec = to.tsp_time.tv_usec;
81 mstotvround(&tmptv, corr);
82 to.tsp_time.tv_sec = tmptv.tv_sec;
83 to.tsp_time.tv_usec = tmptv.tv_usec;
84 to.tsp_type = TSP_ADJTIME;
86 (void)strcpy(to.tsp_name, hostname);
87 answer = acksend(&to, &htp->addr, htp->name,
90 htp->delta = HOSTDOWN;
92 "no reply to time correction from %s",
94 if (++htp->noanswer >= LOSTHOST) {
97 "purging %s for not answering\n",
108 * adjust our own clock now that we are not sending it out
116 struct timeval *corr;
118 static int passes = 0;
119 static int smoother = 0;
120 long delta; /* adjustment in usec */
125 if (!timerisset(corr))
129 if (adj.tv_sec < MAXADJ && adj.tv_sec > - MAXADJ) {
130 delta = adj.tv_sec*1000000 + adj.tv_usec;
131 /* If the correction is less than the minimum round
132 * trip time for an ICMP packet, and thus
133 * less than the likely error in the measurement,
134 * do not do the entire correction. Do half
135 * or a quarter of it.
138 if (delta > -MIN_ROUND*1000
139 && delta < MIN_ROUND*1000) {
142 ndelta = delta >> smoother;
145 "trimming delta %ld usec to %ld\n",
147 adj.tv_usec = ndelta;
149 } else if (smoother > 0) {
152 if (0 > adjtime(corr, 0)) {
153 syslog(LOG_ERR, "adjtime: %m");
156 && (delta < -BIG_ADJ || delta > BIG_ADJ)) {
160 "large time adjustment of %+.3f sec",
165 "clock correction %ld sec too large to adjust",
167 (void) gettimeofday(&now, 0);
168 timevaladd(&now, corr);
169 if (settimeofday(&now, 0) < 0)
170 syslog(LOG_ERR, "settimeofday: %m");
175 /* adjust the time in a message by the time it
179 adj_msg_time(msg, now)
183 msg->tsp_time.tv_sec += (now->tv_sec - from_when.tv_sec);
184 msg->tsp_time.tv_usec += (now->tv_usec - from_when.tv_usec);
186 while (msg->tsp_time.tv_usec < 0) {
187 msg->tsp_time.tv_sec--;
188 msg->tsp_time.tv_usec += 1000000;
190 while (msg->tsp_time.tv_usec >= 1000000) {
191 msg->tsp_time.tv_sec++;
192 msg->tsp_time.tv_usec -= 1000000;