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
54 struct timeval adjlocal, tmptv;
58 mstotvround(&adjlocal, avdelta);
60 for (htp = self.l_fwd; htp != &self; htp = htp->l_fwd) {
61 if (htp->delta != HOSTDOWN) {
62 corr = avdelta - htp->delta;
63 /* If the other machine is off in the weeds, set its time directly.
64 * If a slave gets the wrong day, the original code would simply
65 * fix the minutes. If you fix a network partition, you can get
66 * into such situations.
69 || corr >= MAXADJ*1000
70 || corr <= -MAXADJ*1000) {
72 (void)gettimeofday(&tmptv,0);
73 timevaladd(&tmptv, &adjlocal);
74 to.tsp_time.tv_sec = tmptv.tv_sec;
75 to.tsp_time.tv_usec = tmptv.tv_usec;
76 to.tsp_type = TSP_SETTIME;
78 tmptv.tv_sec = to.tsp_time.tv_sec;
79 tmptv.tv_usec = to.tsp_time.tv_usec;
80 mstotvround(&tmptv, corr);
81 to.tsp_time.tv_sec = tmptv.tv_sec;
82 to.tsp_time.tv_usec = tmptv.tv_usec;
83 to.tsp_type = TSP_ADJTIME;
85 (void)strcpy(to.tsp_name, hostname);
86 answer = acksend(&to, &htp->addr, htp->name,
89 htp->delta = HOSTDOWN;
91 "no reply to time correction from %s",
93 if (++htp->noanswer >= LOSTHOST) {
96 "purging %s for not answering\n",
107 * adjust our own clock now that we are not sending it out
114 adjclock(struct timeval *corr)
116 static int passes = 0;
117 static int smoother = 0;
118 long delta; /* adjustment in usec */
123 if (!timerisset(corr))
127 if (adj.tv_sec < MAXADJ && adj.tv_sec > - MAXADJ) {
128 delta = adj.tv_sec*1000000 + adj.tv_usec;
129 /* If the correction is less than the minimum round
130 * trip time for an ICMP packet, and thus
131 * less than the likely error in the measurement,
132 * do not do the entire correction. Do half
133 * or a quarter of it.
136 if (delta > -MIN_ROUND*1000
137 && delta < MIN_ROUND*1000) {
140 ndelta = delta >> smoother;
143 "trimming delta %ld usec to %ld\n",
145 adj.tv_usec = ndelta;
147 } else if (smoother > 0) {
150 if (0 > adjtime(corr, 0)) {
151 syslog(LOG_ERR, "adjtime: %m");
154 && (delta < -BIG_ADJ || delta > BIG_ADJ)) {
158 "large time adjustment of %+.3f sec",
163 "clock correction %jd sec too large to adjust",
164 (intmax_t)adj.tv_sec);
165 (void) gettimeofday(&now, 0);
166 timevaladd(&now, corr);
167 if (settimeofday(&now, 0) < 0)
168 syslog(LOG_ERR, "settimeofday: %m");
173 /* adjust the time in a message by the time it
177 adj_msg_time(struct tsp *msg, struct timeval *now)
179 msg->tsp_time.tv_sec += (now->tv_sec - from_when.tv_sec);
180 msg->tsp_time.tv_usec += (now->tv_usec - from_when.tv_usec);
182 while (msg->tsp_time.tv_usec < 0) {
183 msg->tsp_time.tv_sec--;
184 msg->tsp_time.tv_usec += 1000000;
186 while (msg->tsp_time.tv_usec >= 1000000) {
187 msg->tsp_time.tv_sec++;
188 msg->tsp_time.tv_usec -= 1000000;