slave.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 584 行 · 第 1/2 页

#ifndef lint
static  char    *sccsid = "@(#)slave.c	4.1  (ULTRIX)        7/2/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1988 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/
/*
 * Copyright (c) 1985 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *static char sccsid[] = "@(#)slave.c	2.16 (Berkeley) 6/5/86";
 */


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

extern jmp_buf jmpenv;

extern u_short sequence;

slave()
{
	int length;
	int senddateack;
	long electiontime, refusetime, looktime;
	u_short seq;
	char candidate[MAXHOSTNAMELEN];
	struct tsp *msg, to, *readmsg();
	struct sockaddr_in saveaddr, msaveaddr;
	struct timeval wait;
	struct timeval time, otime;
	struct tsp *answer, *acksend();
	int timeout();
	char *date();
	long casual();
	int bytenetorder();
	char olddate[32];
	struct sockaddr_in server;
	register struct netinfo *ntp;
	int ind;
	struct tsp resp;
	extern int Mflag;
	extern int justquit;
#ifdef MEASURE
	extern FILE *fp;
#endif
	if (slavenet) {
		resp.tsp_type = TSP_SLAVEUP;
		resp.tsp_vers = TSPVERSION;
		(void)strcpy(resp.tsp_name, hostname);
		bytenetorder(&resp);
		if (sendto(sock, (char *)&resp, sizeof(struct tsp), 0,
		    &slavenet->dest_addr, sizeof(struct sockaddr_in)) < 0) {
			syslog(LOG_ERR, "sendto: %m");
			exit(1);
		}
	}

	if (status & MASTER) {
#ifdef MEASURE
		if (fp == NULL) {
			fp = fopen("/usr/adm/timed.masterlog", "w");
			setlinebuf(fp);
		}
#endif
		syslog(LOG_INFO, "THIS MACHINE IS A SUBMASTER");
		if (trace) {
			fprintf(fd, "THIS MACHINE IS A SUBMASTER\n");
		}
		for (ntp = nettab; ntp != NULL; ntp = ntp->next)
			if (ntp->status == MASTER)
				masterup(ntp);

	} else {
		syslog(LOG_INFO, "THIS MACHINE IS A SLAVE");
		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;
	if (Mflag)
		if (justquit)
			looktime = time.tv_sec + delay2;
		else 
			looktime = 1;
	else
		looktime = 0;

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);
	}
	if (looktime && time.tv_sec > looktime) {
		if (trace) 
			fprintf(fd, "Looking for nets to master and loops\n");
		
		if (nignorednets > 0) {
			for (ntp = nettab; ntp != NULL; ntp = ntp->next) {
				if (ntp->status == IGNORE) {
					lookformaster(ntp);
					if (ntp->status == MASTER)
						masterup(ntp);
					else
						ntp->status = IGNORE;
				}
			}
			setstatus();
#ifdef MEASURE
			/*
			 * Check to see if we just became master
			 * (file not open)
			 */
			if (fp == NULL) {
				fp = fopen("/usr/adm/timed.masterlog", "w");
				setlinebuf(fp);
			}
#endif
		}

		for (ntp = nettab; ntp != NULL; ntp = ntp->next) {
		    if (ntp->status == MASTER) {
			to.tsp_type = TSP_LOOP;
			to.tsp_vers = TSPVERSION;
			to.tsp_seq = sequence++;
			to.tsp_hopcnt = 10;
			(void)strcpy(to.tsp_name, hostname);
			bytenetorder(&to);
			if (sendto(sock, (char *)&to, sizeof(struct tsp), 0,
			    &ntp->dest_addr, sizeof(struct sockaddr_in)) < 0) {
				syslog(LOG_ERR, "sendto: %m");
				exit(1);
			}
		    }
		}
		(void)gettimeofday(&time, (struct timezone *)0);
		looktime = time.tv_sec + delay2;
	}
	wait.tv_sec = electiontime - time.tv_sec + 10;
	wait.tv_usec = 0;
	msg = readmsg(TSP_ANY, (char *)ANYADDR, &wait, (struct netinfo *)NULL);
	if (msg != NULL) {
		switch (msg->tsp_type) {
		case TSP_SETDATE:
#ifdef TESTING
		case TSP_TEST:
#endif
		case TSP_MSITE:
		case TSP_TRACEOFF:
		case TSP_TRACEON:
			break;
		case TSP_MASTERUP:
			if (fromnet == NULL) {
				if (trace) {
					fprintf(fd, "slave ignored: ");
					print(msg, &from);
				}
				goto loop;
			}
			break;
		default:
			if (fromnet == NULL || fromnet->status == IGNORE) {
				if (trace) {
					fprintf(fd, "slave ignored: ");
					print(msg, &from);
				}
				goto loop;
			}
			break;
		}

		switch (msg->tsp_type) {

		case TSP_ADJTIME:
			if (External_source)
                                break;
			if (fromnet->status != SLAVE)
				break;
			(void)gettimeofday(&time, (struct timezone *)0);
			electiontime = time.tv_sec + delay2;
			if (seq != msg->tsp_seq) {
				seq = msg->tsp_seq;
				if ((status & SUBMASTER) == SUBMASTER) {
					synch((msg->tsp_time.tv_sec * 1000) + 
					    (msg->tsp_time.tv_usec / 1000));
				} else {
					adjclock(&(msg->tsp_time));
				}
			}
			break;
		case TSP_SETTIME:
			if (External_source)
				break;
			if (fromnet->status != SLAVE)
				break;
			if (seq == msg->tsp_seq)
				break;

			seq = msg->tsp_seq;

			(void)strcpy(olddate, date());
			(void)gettimeofday(&otime, (struct timezone *)0);
			(void)settimeofday(&msg->tsp_time,
				(struct timezone *)0);
			syslog(LOG_NOTICE, "date changed by %s from: %s",
				msg->tsp_name, olddate);
			logwtmp(otime, msg->tsp_time);
			if ((status & SUBMASTER) == SUBMASTER)
				spreadtime();
			(void)gettimeofday(&time, (struct timezone *)0);
			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, "sendto: %m");
					exit(1);
				}
			}
			break;
		case TSP_MASTERUP:
			if (slavenet && fromnet != slavenet)
				break;
			makeslave(fromnet);
			setstatus();
			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, "sendto: %m");
				exit(1);
			}
			backoff = 1;
			delay2 = casual((long)MINTOUT, (long)MAXTOUT);
			(void)gettimeofday(&time, (struct timezone *)0);
			electiontime = time.tv_sec + delay2;
			refusetime = 0;
			break;
		case TSP_MASTERREQ:
			if (fromnet->status != SLAVE)
				break;
			(void)gettimeofday(&time, (struct timezone *)0);
			electiontime = time.tv_sec + delay2;
			break;
		case TSP_SETDATE:
			saveaddr = from;