+/*
+ * 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[] = "@(#)slave.c 1.1 (Berkeley) %G%";
+#endif not lint
+
+#include "globals.h"
+#include <protocols/timed.h>
+#include <setjmp.h>
+
+#define OFF 0
+#define ON 1
+
+extern long delay1;
+extern long delay2;
+extern int trace;
+extern int sock;
+extern struct sockaddr_in from;
+extern struct sockaddr_in server;
+extern char hostname[];
+extern char *fj;
+extern FILE *fd;
+
+slave()
+{
+ int length;
+ int senddateack;
+ long electiontime, refusetime;
+ u_short seq;
+ char candidate[32];
+ struct tsp *msg, *readmsg();
+ extern int backoff;
+ struct sockaddr_in saveaddr;
+ extern jmp_buf jmpenv;
+ struct timeval wait;
+ struct timeval time;
+ struct timezone tzone;
+ struct tsp *answer, *acksend();
+ int timeout();
+ char *date(), *strcpy();
+ long casual();
+ int bytenetorder();
+
+ syslog(LOG_ERR, "timed: THIS MACHINE IS A SLAVE\n");
+ if (trace) {
+ fprintf(fd, "THIS MACHINE IS A SLAVE\n");
+ }
+
+ seq = 0;
+ senddateack = OFF;
+ refusetime = 0;
+
+ (void)gettimeofday(&time, (struct timezone *)0);
+ electiontime = time.tv_sec + delay2;
+
+loop:
+ length = sizeof(struct sockaddr_in);
+ (void)gettimeofday(&time, (struct timezone *)0);
+ if (time.tv_sec > electiontime) {
+ if (trace)
+ fprintf(fd, "election timer expired\n");
+ longjmp(jmpenv, 1);
+ }
+ wait.tv_sec = electiontime - time.tv_sec + 10;
+ wait.tv_usec = 0;
+ msg = readmsg(TSP_ANY, (char *)ANYADDR, &wait);
+ if (msg != NULL) {
+ switch (msg->tsp_type) {
+
+ case TSP_ADJTIME:
+ (void)gettimeofday(&time, (struct timezone *)0);
+ electiontime = time.tv_sec + delay2;
+ if (seq != msg->tsp_seq) {
+ seq = msg->tsp_seq;
+ adjclock(&(msg->tsp_time));
+ }
+ break;
+ case TSP_SETTIME:
+ if (seq == msg->tsp_seq)
+ goto endsettime;
+
+ seq = msg->tsp_seq;
+
+ (void)gettimeofday(&time, &tzone);
+ time.tv_sec = msg->tsp_time.tv_sec;
+ time.tv_usec = 500000;
+ (void)settimeofday(&time, &tzone);
+ syslog(LOG_ERR, "timed: date changed to: %s\n",
+ date());
+ electiontime = time.tv_sec + delay2;
+
+ if (senddateack == ON) {
+ senddateack = OFF;
+ msg->tsp_type = TSP_DATEACK;
+ (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, "timed: sendto: %m");
+ exit(1);
+ }
+ }
+endsettime:
+ break;
+ case TSP_MASTERUP:
+ msg->tsp_type = TSP_SLAVEUP;
+ msg->tsp_vers = TSPVERSION;
+ (void)strcpy(msg->tsp_name, hostname);
+ bytenetorder(msg);
+ answerdelay();
+ length = sizeof(struct sockaddr_in);
+ if (sendto(sock, (char *)msg, sizeof(struct tsp), 0,
+ &from, length) < 0) {
+ syslog(LOG_ERR, "timed: sendto: %m");
+ exit(1);
+ }
+ backoff = 1;
+ delay2 = casual((long)MINTOUT, (long)MAXTOUT);
+ (void)gettimeofday(&time, (struct timezone *)0);
+ electiontime = time.tv_sec + delay2;
+ break;
+ case TSP_MASTERREQ:
+ (void)gettimeofday(&time, (struct timezone *)0);
+ electiontime = time.tv_sec + delay2;
+ break;
+ case TSP_DATE:
+ saveaddr = from;
+ msg->tsp_time.tv_usec = 0;
+ msg->tsp_type = TSP_DATEREQ;
+ msg->tsp_vers = TSPVERSION;
+ (void)strcpy(msg->tsp_name, hostname);
+ answer = acksend(msg, (char *)ANYADDR, TSP_DATEACK);
+ if (answer != NULL) {
+ msg->tsp_type = TSP_ACK;
+ bytenetorder(msg);
+ length = sizeof(struct sockaddr_in);
+ if (sendto(sock, (char *)msg,
+ sizeof(struct tsp), 0,
+ &saveaddr, length) < 0) {
+ syslog(LOG_ERR, "timed: sendto: %m");
+ exit(1);
+ }
+ senddateack = ON;
+ }
+ 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)close((int)fd);
+ }
+ trace = OFF;
+ break;
+ case TSP_ELECTION:
+ (void)gettimeofday(&time, (struct timezone *)0);
+ electiontime = time.tv_sec + delay2;
+ seq = 0; /* reset sequence number */
+ if (time.tv_sec < refusetime)
+ msg->tsp_type = TSP_REFUSE;
+ else {
+ msg->tsp_type = TSP_ACCEPT;
+ refusetime = time.tv_sec + 30;
+ }
+ (void)strcpy(candidate, msg->tsp_name);
+ (void)strcpy(msg->tsp_name, hostname);
+ answerdelay();
+ server = from;
+ answer = acksend(msg, candidate, TSP_ACK);
+ if (answer == NULL) {
+ syslog(LOG_ERR, "timed: problem in election\n");
+ }
+ break;
+ case TSP_MSITE:
+ saveaddr = from;
+ msg->tsp_type = TSP_MSITEREQ;
+ msg->tsp_vers = TSPVERSION;
+ (void)strcpy(msg->tsp_name, hostname);
+ answer = acksend(msg, (char *)ANYADDR, TSP_ACK);
+ if (answer != NULL) {
+ msg->tsp_type = TSP_ACK;
+ length = sizeof(struct sockaddr_in);
+ bytenetorder(msg);
+ if (sendto(sock, (char *)msg,
+ sizeof(struct tsp), 0,
+ &saveaddr, length) < 0) {
+ syslog(LOG_ERR, "timed: sendto: %m");
+ exit(1);
+ }
+ }
+ break;
+ case TSP_ACCEPT:
+ case TSP_REFUSE:
+ case TSP_SLAVEUP:
+ case TSP_DATEREQ:
+ break;
+#ifdef TESTING
+ case TSP_TEST:
+ electiontime = 0;
+ break;
+#endif
+ default:
+ if (trace) {
+ fprintf(fd, "garbage: ");
+ print(msg);
+ }
+ break;
+ }
+ }
+ goto loop;
+}
+
+/*
+ * Used before answering a broadcast message to avoid network
+ * contention and likely collisions.
+ */
+answerdelay()
+{
+ struct timeval time, timeout;
+
+ (void)gettimeofday(&time, (struct timezone *)0);
+ timeout.tv_sec = time.tv_sec;
+ timeout.tv_usec = time.tv_usec + delay1;
+
+ while (timercmp(&time, &timeout, <)) {
+ (void)gettimeofday(&time, (struct timezone *)0);
+ }
+
+ return;
+}
projects / unix-history / commitdiff