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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 1.2 2003/06/17 04:30:03 dillon Exp $
40 #include <sys/types.h>
41 #include <sys/times.h>
43 #include <sys/syssgi.h>
46 static void adjclock __P((struct timeval *));
49 * sends to the slaves the corrections for their clocks after fixing our
58 struct timeval adjlocal;
62 mstotvround(&adjlocal, avdelta);
64 for (htp = self.l_fwd; htp != &self; htp = htp->l_fwd) {
65 if (htp->delta != HOSTDOWN) {
66 corr = avdelta - htp->delta;
67 /* If the other machine is off in the weeds, set its time directly.
68 * If a slave gets the wrong day, the original code would simply
69 * fix the minutes. If you fix a network partition, you can get
70 * into such situations.
73 || corr >= MAXADJ*1000
74 || corr <= -MAXADJ*1000) {
76 (void)gettimeofday(&to.tsp_time,0);
77 timevaladd(&to.tsp_time, &adjlocal);
78 to.tsp_type = TSP_SETTIME;
80 mstotvround(&to.tsp_time, corr);
81 to.tsp_type = TSP_ADJTIME;
83 (void)strcpy(to.tsp_name, hostname);
84 answer = acksend(&to, &htp->addr, htp->name,
87 htp->delta = HOSTDOWN;
89 "no reply to time correction from %s",
91 if (++htp->noanswer >= LOSTHOST) {
94 "purging %s for not answering\n",
105 * adjust our own clock now that we are not sending it out
113 struct timeval *corr;
115 static int passes = 0;
116 static int smoother = 0;
117 long delta; /* adjustment in usec */
122 if (!timerisset(corr))
126 if (adj.tv_sec < MAXADJ && adj.tv_sec > - MAXADJ) {
127 delta = adj.tv_sec*1000000 + adj.tv_usec;
128 /* If the correction is less than the minimum round
129 * trip time for an ICMP packet, and thus
130 * less than the likely error in the measurement,
131 * do not do the entire correction. Do half
132 * or a quarter of it.
135 if (delta > -MIN_ROUND*1000
136 && delta < MIN_ROUND*1000) {
139 ndelta = delta >> smoother;
142 "trimming delta %ld usec to %ld\n",
144 adj.tv_usec = ndelta;
146 } else if (smoother > 0) {
149 if (0 > adjtime(corr, 0)) {
150 syslog(LOG_ERR, "adjtime: %m");
153 && (delta < -BIG_ADJ || delta > BIG_ADJ)) {
157 "large time adjustment of %+.3f sec",
162 "clock correction %d sec too large to adjust",
164 (void) gettimeofday(&now, 0);
165 timevaladd(&now, corr);
166 if (settimeofday(&now, 0) < 0)
167 syslog(LOG_ERR, "settimeofday: %m");
171 /* Accumulate the total change, and use it to adjust the basic
175 #define F_USEC_PER_SEC (1000000*1.0) /* reduce typos */
176 #define F_NSEC_PER_SEC (F_USEC_PER_SEC*1000.0)
178 extern char *timetrim_fn;
179 extern char *timetrim_wpat;
180 extern long timetrim;
181 extern double tot_adj, hr_adj; /* totals in nsec */
182 extern double tot_ticks, hr_ticks;
184 static double nag_tick;
185 double cur_ticks, hr_delta_ticks, tot_delta_ticks;
186 double tru_tot_adj, tru_hr_adj; /* nsecs of adjustment */
187 double tot_trim, hr_trim; /* nsec/sec */
191 cur_ticks = times(&tm);
192 tot_adj += delta*1000.0;
193 hr_adj += delta*1000.0;
195 tot_delta_ticks = cur_ticks-tot_ticks;
196 if (tot_delta_ticks >= 16*SECDAY*CLK_TCK) {
197 tot_adj -= rint(tot_adj/16);
198 tot_ticks += rint(tot_delta_ticks/16);
199 tot_delta_ticks = cur_ticks-tot_ticks;
201 hr_delta_ticks = cur_ticks-hr_ticks;
203 tru_hr_adj = hr_adj + timetrim*rint(hr_delta_ticks/CLK_TCK);
204 tru_tot_adj = (tot_adj
205 + timetrim*rint(tot_delta_ticks/CLK_TCK));
207 if (hr_delta_ticks >= SECDAY*CLK_TCK
208 || (tot_delta_ticks < 4*SECDAY*CLK_TCK
209 && hr_delta_ticks >= SECHR*CLK_TCK)
210 || (trace && hr_delta_ticks >= (SECHR/10)*CLK_TCK)) {
212 tot_trim = rint(tru_tot_adj*CLK_TCK/tot_delta_ticks);
213 hr_trim = rint(tru_hr_adj*CLK_TCK/hr_delta_ticks);
216 || (abs(timetrim - hr_trim) > 100000.0
218 && ((cur_ticks - nag_tick)
219 >= 24*SECDAY*CLK_TCK))) {
220 nag_tick = cur_ticks;
222 "%+.3f/%.2f or %+.3f/%.2f sec/hr; timetrim=%+.0f or %+.0f",
223 tru_tot_adj/F_NSEC_PER_SEC,
224 tot_delta_ticks/(SECHR*CLK_TCK*1.0),
225 tru_hr_adj/F_NSEC_PER_SEC,
226 hr_delta_ticks/(SECHR*CLK_TCK*1.0),
231 if (tot_trim < -MAX_TRIM || tot_trim > MAX_TRIM) {
232 tot_ticks = hr_ticks;
234 } else if (0 > syssgi(SGI_SETTIMETRIM,
236 syslog(LOG_ERR, "SETTIMETRIM(%d): %m",
239 if (0 != timetrim_fn) {
240 timetrim_st = fopen(timetrim_fn, "w");
241 if (0 == timetrim_st) {
242 syslog(LOG_ERR, "fopen(%s): %m",
245 if (0 > fprintf(timetrim_st,
254 (void)fclose(timetrim_st);
258 tot_adj -= ((tot_trim - timetrim)
259 * rint(tot_delta_ticks/CLK_TCK));
263 hr_ticks = cur_ticks;
271 /* adjust the time in a message by the time it
275 adj_msg_time(msg, now)
279 msg->tsp_time.tv_sec += (now->tv_sec - from_when.tv_sec);
280 msg->tsp_time.tv_usec += (now->tv_usec - from_when.tv_usec);
282 while (msg->tsp_time.tv_usec < 0) {
283 msg->tsp_time.tv_sec--;
284 msg->tsp_time.tv_usec += 1000000;
286 while (msg->tsp_time.tv_usec >= 1000000) {
287 msg->tsp_time.tv_sec++;
288 msg->tsp_time.tv_usec -= 1000000;