BSD 4_3_Tahoe release

[unix-history] / usr / src / etc / timed / correct.c

/*
* Copyright (c) 1985 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#ifndef lint
static char sccsid[] = "@(#)correct.c   2.5 (Berkeley) 6/18/88";
#endif /* not lint */

#include "globals.h"
#include <protocols/timed.h>

#ifdef MEASURE
extern FILE *fp;
#endif

/* 
* `correct' sends to the slaves the corrections for their clocks
*/

correct(avdelta)
long avdelta;
{
       int i;
       int corr;
       struct timeval adjlocal;
       struct tsp msgs;
       struct timeval mstotvround();
       struct tsp *answer, *acksend();

#ifdef MEASURE
       for(i=0; i<slvcount; i++) {
               if (hp[i].delta == HOSTDOWN)
                       fprintf(fp, "%s\t", "down");
               else { 
                       fprintf(fp, "%d\t", hp[i].delta);
               }
       }
       fprintf(fp, "\n");
#endif
       corr = avdelta - hp[0].delta;
       adjlocal = mstotvround(&corr);
       adjclock(&adjlocal);
#ifdef MEASURE
       fprintf(fp, "%d\t", corr);
#endif

       for(i=1; i<slvcount; i++) {
               if (hp[i].delta != HOSTDOWN)  {
                       corr = avdelta - hp[i].delta;
                       msgs.tsp_time = mstotvround(&corr);
                       msgs.tsp_type = (u_char)TSP_ADJTIME;
                       (void)strcpy(msgs.tsp_name, hostname);
                       answer = acksend(&msgs, &hp[i].addr, hp[i].name,
                           TSP_ACK, (struct netinfo *)NULL);
                       if (answer == NULL) {
                               hp[i].delta = HOSTDOWN;
#ifdef MEASURE
                               fprintf(fp, "%s\t", "down");
                       } else {
                               fprintf(fp, "%d\t", corr);
#endif
                       }
               } else {
#ifdef MEASURE
                       fprintf(fp, "%s\t", "down");
#endif
               }
       }
#ifdef MEASURE
       fprintf(fp, "\n");
#endif
}

/* 
* `mstotvround' rounds up the value of the argument to the 
* nearest multiple of five, and converts it into a timeval 
*/

struct timeval mstotvround(x)
int *x;
{
       int temp;
       struct timeval adj;

       temp = *x % 5;
       if (temp >= 3)
               *x = *x-temp+5;
       else {
               if (temp <= -3)
                       *x = *x - temp -5;
               else 
                       *x = *x-temp;
       }
       adj.tv_sec = *x/1000;
       adj.tv_usec = (*x-adj.tv_sec*1000)*1000;
       if (adj.tv_usec < 0) {
               adj.tv_usec += 1000000;
               adj.tv_sec--;
       }
       return(adj);
}

adjclock(corr)
struct timeval *corr;
{
       struct timeval now;

       if (timerisset(corr)) {
               if (corr->tv_sec < MAXADJ && corr->tv_sec > - MAXADJ) {
                       (void)adjtime(corr, (struct timeval *)0);
               } else {
                       syslog(LOG_WARNING,
                           "clock correction too large to adjust (%d sec)",
                           corr->tv_sec);
                       (void) gettimeofday(&now, (struct timezone *)0);
                       timevaladd(&now, corr);
                       if (settimeofday(&now, (struct timezone *)0) < 0)
                               syslog(LOG_ERR, "can't set time");
               }
       }
}

timevaladd(tv1, tv2)
       register struct timeval *tv1, *tv2;
{
       
       tv1->tv_sec += tv2->tv_sec;
       tv1->tv_usec += tv2->tv_usec;
       if (tv1->tv_usec >= 1000000) {
               tv1->tv_sec++;
               tv1->tv_usec -= 1000000;
       }
       if (tv1->tv_usec < 0) {
               tv1->tv_sec--;
               tv1->tv_usec += 1000000;
       }
}