projects / unix-history / blob
? search:
summary | tags | clone url | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
should ack QUIT's as well
[unix-history] / usr / src / usr.sbin / timed / timed / master.c
/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#ifndef lint
static char sccsid[] = "@(#)master.c 1.3 (Berkeley) %G%";
#endif not lint
#include "globals.h"
#include <protocols/timed.h>
#include <setjmp.h>
extern struct sockaddr_in from;
extern struct sockaddr_in server;
extern int trace;
extern int machup;
extern int slvcount;
extern int measure_delta;
extern int sock;
extern char hostname[];
extern struct host hp[];
extern char *fj;
extern FILE *fd;
#ifdef MEASURE
int header;
char *fi;
FILE *fp;
#endif
/*
* The main function of `master' is to periodically compute the differences
* (deltas) between its clock and the clocks of the slaves, to compute the
* network average delta, and to send to the slaves the differences between
* their individual deltas and the network delta.
* While waiting, it receives messages from the slaves (i.e. requests for
* master's name, remote requests to set the network time, ...), and
* takes the appropriate action.
*/
master()
{
int ind;
int length;
long pollingtime;
struct timeval wait;
struct timeval time;
struct timezone tzone;
struct timeval mytime;
struct tsp *msg, to;
struct sockaddr_in saveaddr;
extern jmp_buf jmpenv;
int findhost();
char *date();
char *strcpy();
struct tsp *readmsg();
struct tsp *answer, *acksend();
char olddate[32];
#ifdef MEASURE
fi = "/usr/adm/timed.masterlog";
fp = fopen(fi, "w");
#endif
syslog(LOG_INFO, "THIS MACHINE IS MASTER");
if (trace)
fprintf(fd, "THIS MACHINE IS MASTER\n");
masterup();
pollingtime = 0;
loop:
(void)gettimeofday(&time, (struct timezone *)0);
if (time.tv_sec >= pollingtime) {
pollingtime = time.tv_sec + SAMPLEINTVL;
synch();
}
wait.tv_sec = pollingtime - time.tv_sec;
wait.tv_usec = 0;
msg = readmsg(TSP_ANY, (char *)ANYADDR, &wait);
if (msg != NULL) {
switch (msg->tsp_type) {
case TSP_MASTERREQ:
ind = addmach(msg->tsp_name);
if (trace)
prthp();
if (hp[ind].seq != msg->tsp_seq) {
hp[ind].seq = msg->tsp_seq;
bcopy((char *)&hp[ind].addr,
(char *)&(server.sin_addr.s_addr),
hp[ind].length);
to.tsp_type = TSP_SETTIME;
(void)strcpy(to.tsp_name, hostname);
/*
* give the upcoming slave the time
* to check its input queue before
* setting the time
*/
sleep(1);
to.tsp_time.tv_usec = 0;
(void)gettimeofday(&mytime, (struct timezone *)0);
to.tsp_time.tv_sec = mytime.tv_sec;
answer = acksend(&to, hp[ind].name, TSP_ACK);
if (answer == NULL) {
syslog(LOG_ERR, "ERROR ON SETTIME machine: %s", hp[ind].name);
slvcount--;
}
}
break;
case TSP_SLAVEUP:
(void) addmach(msg->tsp_name);
break;
case TSP_DATE:
saveaddr = from;
msg->tsp_time.tv_usec = 0;
/*
* the following line is necessary due to syslog
* calling ctime() which clobbers the static buffer
*/
(void)strcpy(olddate, date());
(void)gettimeofday(&time, &tzone);
time.tv_sec += msg->tsp_time.tv_sec;
time.tv_sec++;
(void)settimeofday(&time, &tzone);
syslog(LOG_NOTICE, "date changed from: %s", olddate);
msg->tsp_type = TSP_DATEACK;
msg->tsp_vers = TSPVERSION;
(void)strcpy(msg->tsp_name, hostname);
bytenetorder(msg);
length = sizeof(struct sockaddr_in);
if (sendto(sock, (char *)msg, sizeof(struct tsp), 0,
&saveaddr, length) < 0) {
syslog(LOG_ERR, "sendto: %m");
exit(1);
}
spreadtime();
pollingtime = 0;
break;
case TSP_DATEREQ:
ind = findhost(msg->tsp_name);
if (ind < 0) {
syslog(LOG_ERR,
"DATEREQ from uncontrolled machine");
break;
}
if (hp[ind].seq != msg->tsp_seq) {
hp[ind].seq = msg->tsp_seq;
msg->tsp_time.tv_usec = 0;
/*
* the following line is necessary due to syslog
* calling ctime() which clobbers the static buffer
*/
(void)strcpy(olddate, date());
(void)gettimeofday(&time, &tzone);
time.tv_sec += msg->tsp_time.tv_sec;
time.tv_sec++;
(void)settimeofday(&time, &tzone);
syslog(LOG_NOTICE,
"date changed by %s from: %s",
msg->tsp_name, olddate);
spreadtime();
pollingtime = 0;
}
break;
case TSP_MSITE:
msg->tsp_type = TSP_ACK;
msg->tsp_vers = TSPVERSION;
(void)strcpy(msg->tsp_name, hostname);
bytenetorder(msg);
length = sizeof(struct sockaddr_in);
if (sendto(sock, (char *)msg, sizeof(struct tsp), 0,
&from, length) < 0) {
syslog(LOG_ERR, "sendto: %m");
exit(1);
}
break;
case TSP_MSITEREQ:
break;
case TSP_TRACEON:
if (!(trace)) {
fd = fopen(fj, "w");
fprintf(fd, "Tracing started on: %s\n\n",
date());
(void)fflush(fd);
}
trace = ON;
break;
case TSP_TRACEOFF:
if (trace) {
fprintf(fd, "Tracing ended on: %s\n", date());
(void)fflush(fd);
(void)fclose(fd);
}
trace = OFF;
break;
case TSP_ELECTION:
to.tsp_type = TSP_QUIT;
(void)strcpy(to.tsp_name, hostname);
server = from;
answer = acksend(&to, msg->tsp_name, TSP_ACK);
if (answer == NULL) {
syslog(LOG_ERR, "election error");
} else {
(void) addmach(msg->tsp_name);
}
pollingtime = 0;
break;
case TSP_CONFLICT:
/*
* After a network partition, there can be
* more than one master: the first slave to
* come up will notify here the situation.
*/
(void)strcpy(to.tsp_name, hostname);
for(;;) {
to.tsp_type = TSP_RESOLVE;
answer = acksend(&to, (char *)ANYADDR,
TSP_MASTERACK);
if (answer == NULL)
break;
to.tsp_type = TSP_QUIT;
server = from;
msg = acksend(&to, answer->tsp_name,
TSP_MASTERACK);
if (msg == NULL) {
syslog(LOG_ERR, "error on sending QUIT");
} else {
(void) addmach(answer->tsp_name);
}
}
masterup();
pollingtime = 0;
break;
case TSP_RESOLVE:
/*
* do not want to call synch() while waiting
* to be killed!
*/
(void)gettimeofday(&time, (struct timezone *)0);
pollingtime = time.tv_sec + SAMPLEINTVL;
break;
case TSP_QUIT:
/* become slave */
#ifdef MEASURE
(void)fclose(fp);
#endif
longjmp(jmpenv, 2);
break;
default:
if (trace) {
fprintf(fd, "garbage: ");
print(msg);
}
break;
}
}
goto loop;
}
/*
* `synch' synchronizes all the slaves by calling measure,
* networkdelta and correct
*/
synch()
{
int i;
int measure_status;
long netdelta;
struct timeval tack;
#ifdef MEASURE
#define MAXLINES 8
static int lines = 1;
struct timeval start, end;
#endif
int measure();
int correct();
long networkdelta();
char *date();
if (slvcount > 1) {
#ifdef MEASURE
(void)gettimeofday(&start, (struct timezone *)0);
if (header == ON || --lines == 0) {
fprintf(fp, "%s\n", date());
for (i=0; i<slvcount; i++)
fprintf(fp, "%.7s\t", hp[i].name);
fprintf(fp, "\n");
lines = MAXLINES;
header = OFF;
}
#endif
machup = 1;
hp[0].delta = 0;
for(i=1; i<slvcount; i++) {
bcopy((char *)&hp[i].addr,
(char *)&(server.sin_addr.s_addr),
hp[i].length);
tack.tv_sec = 0;
tack.tv_usec = 100000;
if ((measure_status = measure(&tack, ON)) < 0) {
syslog(LOG_ERR, "measure: %m");
exit(1);
}
hp[i].delta = measure_delta;
if (measure_status == GOOD)
machup++;
}
if (machup > 1) {
netdelta = networkdelta();
correct(netdelta);
}
#ifdef MEASURE
gettimeofday(&end, 0);
end.tv_sec -= start.tv_sec;
end.tv_usec -= start.tv_usec;
if (end.tv_usec < 0) {
end.tv_sec -= 1;
end.tv_usec += 1000000;
}
fprintf(fp, "%d ms.\n", (end.tv_sec*1000+end.tv_usec/1000));
(void)fflush(fp);
#endif
for(i=1; i<slvcount; i++) {
if (hp[i].delta == HOSTDOWN) {
free((char *)hp[i].name);
hp[i] = hp[--slvcount];
#ifdef MEASURE
header = ON;
#endif
}
}
}
}
/*
* 'spreadtime' sends the time to each slave after the master
* has received the command to set the network time
*/
spreadtime()
{
int i;
struct tsp to;
struct tsp *answer, *acksend();
for(i=1; i<slvcount; i++) {
bcopy((char *)&hp[i].addr, (char *)&(server.sin_addr.s_addr),
hp[i].length);
to.tsp_type = TSP_SETTIME;
(void)strcpy(to.tsp_name, hostname);
(void)gettimeofday(&to.tsp_time, (struct timezone *)0);
answer = acksend(&to, hp[i].name, TSP_ACK);
if (answer == NULL) {
syslog(LOG_ERR, "ERROR ON SETTIME machine: %s", hp[i].name);
}
}
}
findhost(name)
char *name;
{
int i;
int ind;
ind = -1;
for (i=1; i<slvcount; i++) {
if (strcmp(name, hp[i].name) == 0) {
ind = i;
break;
}
}
return(ind);
}
/*
* 'addmach' adds a host to the list of controlled machines
* if not already there
*/
addmach(name)
char *name;
{
int ret;
int findhost();
char *malloc();
struct hostent *hptmp, *gethostbyname();
ret = findhost(name);
if (ret < 0) {
hptmp = gethostbyname(name);
if (hptmp == NULL) {
syslog(LOG_ERR, "gethostbyname: %m");
exit(1);
}
hp[slvcount].length = hptmp->h_length;
bcopy((char *)hptmp->h_addr, (char *)&hp[slvcount].addr,
hptmp->h_length);
hp[slvcount].name = (char *)malloc(MAXHOSTNAMELEN);
(void)strcpy(hp[slvcount].name, name);
hp[slvcount].seq = 0;
ret = slvcount;
if (slvcount < NHOSTS)
slvcount++;
else {
syslog(LOG_ALERT, "no more slots in host table");
}
} else {
/* need to clear sequence number anyhow */
hp[ret].seq = 0;
}
#ifdef MEASURE
header = ON;
#endif
return(ret);
}
prthp()
{
int i;
fprintf(fd, "host table:");
for (i=1; i<slvcount; i++)
fprintf(fd, " %s", hp[i].name);
fprintf(fd, "\n");
}
masterup()
{
struct timeval wait;
char *strcpy();
struct tsp to, *msg, *readmsg();
to.tsp_type = TSP_MASTERUP;
(void)strcpy(to.tsp_name, hostname);
broadcast(&to);
for (;;) {
wait.tv_sec = 1;
wait.tv_usec = 0;
msg = readmsg(TSP_SLAVEUP, (char *)ANYADDR, &wait);
if (msg != NULL) {
(void) addmach(msg->tsp_name);
} else
break;
}
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.