ntpd.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 1,502 行 · 第 1/3 页

#ifndef lint
static	char	*sccsid = "@(#)ntpd.c	4.1	(ULTRIX)	7/2/90";
#endif lint
/************************************************************************
 *									*
 *			Copyright (c) 1989-1990 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.	*
 *									*
 ************************************************************************/
#ifndef	lint
static char *rcsid = "$Source: /usr/users/louie/ntp/RCS/ntpd.c,v $ $Revision: 3.4.1.9 $ $Date: 89/05/18 18:30:17 $";
#endif	lint

/*
 *  $Log:	ntpd.c,v $
 * Revision 3.4.1.9  89/05/18  18:30:17  louie
 * Changes in ntpd.c for reference clock support.  Also, a few diddles to
 * accomodate the NeXT computer system that has a slightly different nlist.h
 * 
 * Revision 3.4.1.8  89/05/03  15:16:17  louie
 * Add code to save the value of the drift compensation register to a file every
 * hour.  Add additional configuration file directives which can specify the same
 * information as on the command line.
 * 
 * Revision 3.4.1.7  89/04/10  15:58:45  louie
 * Add -l option to enable logging of clock adjust messages.
 * 
 * Revision 3.4.1.6  89/04/07  19:09:04  louie
 * Added NOSWAP code for Ultrix systems to lock NTP process in memory.  Deleted
 * unused variable in ntpd.c
 * 
 * Revision 3.4.1.5  89/03/31  16:37:49  louie
 * Add support for "trusting" directive in NTP configuration file.  It allows 
 * you to specify at run time if non-configured peers will be synced to.
 * 
 * Revision 3.4.1.4  89/03/29  12:30:46  louie
 * peer->mode has been renamed peer->hmode.  Drop PEER_FL_SYNC since the
 * PEER_FL_CONFIG flag means much the same thing.
 * 
 * Revision 3.4.1.3  89/03/22  18:29:41  louie
 * patch3: Use new RCS headers.
 * 
 * Revision 3.4.1.2  89/03/22  18:03:17  louie
 * The peer->refid field was being htonl()'ed when it was already in network
 * byte order.
 * 
 * Revision 3.4.1.1  89/03/20  00:12:10  louie
 * patch1: Diddle syslog messages a bit.  Handle case of udp/ntp not being
 * patch1: defined in /etc/services.  Compute default value for tickadj if
 * patch1: the change-kernel-tickadj flag is set, but no tickadj directive
 * patch1: is present in the configuration file.
 * 
 * Revision 3.4  89/03/17  18:37:11  louie
 * Latest test release.
 * 
 * Revision 3.3.1.1  89/03/17  18:26:32  louie
 * 1
 * 
 * Revision 3.3  89/03/15  14:19:56  louie
 * New baseline for next release.
 * 
 * Revision 3.2.1.2  89/03/15  13:59:50  louie
 * Initialize random number generator.  The ntpdc query_mode() routine has been
 * revised to send more peers per packet, a count of the total number of peers
 * which will be transmited, the number of packets to be transmitted, and a 
 * sequence number for each packet.  There is a new version number for the
 * ntpdc query packets, which is now symbolically defined in ntp.h
 * 
 * Revision 3.2.1.1  89/03/10  12:27:41  louie
 * Removed reference to HUGE, and replaced it by a suitable large number.  Added
 * some #ifdef DEBUG .. #endif around some debug code that was missing.  Display
 * patchlevel along with version.
 * 
 * Revision 3.2  89/03/07  18:26:30  louie
 * New version of the UNIX NTP daemon based on the 6 March 1989 draft of the
 * new NTP protcol spec.  A bunch of cosmetic changes.  The peer list is
 * now doublely linked, and a subroutine (enqueue()) replaces the ENQUEUE
 * macro used previously.
 * 
 * Revision 3.1.1.1  89/02/15  08:58:46  louie
 * Bugfixes to released version.
 * 
 * 
 * Revision 3.1  89/01/30  14:43:14  louie
 * Second UNIX NTP test release.
 * 
 * Revision 3.0  88/12/12  15:56:38  louie
 * Test release of new UNIX NTP software.  This version should conform to the
 * revised NTP protocol specification.
 * 
 */

#include <stdio.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/uio.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <sys/resource.h>
#include <sys/file.h>
#ifdef NOSWAP
#include <sys/lock.h>
#endif

#include <net/if.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/udp.h>

#include <arpa/inet.h>
#include <netdb.h>
#include <strings.h>
#include <errno.h>
#include <syslog.h>
#include <nlist.h>

#include "ntp.h"
#include "patchlevel.h"

#define	TRUE	1
#define	FALSE	0

struct sockaddr_in dst_sock = {AF_INET};

struct servent *servp;
struct list peer_list;

struct itimerval it;
struct itimerval *itp = &it;
struct timeval tv;
char *prog_name;

char *conf = NTPINITFILE;
char *driftcomp_file = NTPDRIFTCOMP;
static int drift_fd = -1;

#ifdef	DEBUG
int debug = 0;
#endif

#ifdef	SETTICKADJ
int	tickadj = 0;
int	dotickadj = 0;
#endif

#ifdef	NOSWAP
int	noswap = 0;
#endif

int doset = 1;
int ticked;
int selfds;
int trusting = 1;
int logstats;

double WayTooBig = WAYTOOBIG;
unsigned long clock_watchdog;

struct ntpdata ntpframe;
struct sysdata sys;

extern int errno;
extern char *malloc(), *ntoa();
extern double s_fixed_to_double(), ul_fixed_to_double();

void finish(), timeout(), tock(), make_new_peer(), init_ntp(), initialize(),
	init_kern_vars(), hourly();
extern void transmit(), process_packet(), clock_update(),
	clear(), clock_filter(), select_clock();

extern void init_logical_clock();

main(argc, argv)
	int argc;
	char *argv[];
{
	struct sockaddr_in *dst = &dst_sock;
	struct ntpdata *pkt = &ntpframe;
	fd_set readfds, tmpmask;
	int dstlen = sizeof(struct sockaddr_in);
	int cc;
	register int i;
	extern char *optarg;
	extern int atoi();

#if	defined(DEBUG) && defined(SIGUSR1) && defined(SIGUSR2)
	void incdebug(), decdebug();
#endif
	initialize();		/* call NTP protocol initialization first,
				   then allow others to override default
				   values */
	prog_name = argv[0];
	while ((cc = getopt(argc, argv, "a:c:dD:lstn")) != EOF) {
		switch (cc) {
		case 'a':
			if (strcmp(optarg, "any") == 0)
				WayTooBig = 10e15;
			else
				WayTooBig = atof(optarg);
			break;

		case 'd':
#ifdef	DEBUG
			debug++;
#else
			fprintf(stderr, "%s: not compiled with DEBUG\n",
				prog_name);
#endif
			break;

		case 'D':
#ifdef	DEBUG
			debug = atoi(optarg);
#else
			fprintf(stderr, "%s: not compiled with DEBUG\n",
				prog_name);
#endif
			break;

		case 's':
			doset = 0;
			break;

		case 't':
#ifdef	SETTICKADJ
			dotickadj++;
#else
			fprintf(stderr, "%s: not compiled to set tickadj\n",
				prog_name);
#endif
			break;

		case 'n':
#ifdef	NOSWAP
			noswap = 1;
#else
			fprintf(stderr, "%s: not compiled for noswap\n",
				prog_name);
#endif
			break;

		case 'l':
			logstats = 1;
			break;

		case 'c':
			conf = optarg;
			break;

		default:
			fprintf(stderr, "ntpd: -%c: unknown option\n", cc);
			break;
		}
	}

#ifdef	DEBUG
	if (!debug) {
#endif
		if (fork())
			exit(0);

		{
			int s;
			for (s = getdtablesize(); s >= 0; s--)
				(void) close(s);
			(void) open("/", 0);
			(void) dup2(0, 1);
			(void) dup2(0, 2);
			(void) setpgrp(0, getpid());
			s = open("/dev/tty", 2);
			if (s >= 0) {
				(void) ioctl(s, (u_long) TIOCNOTTY, (char *) 0);
				(void) close(s);
			}
		}
#ifdef	DEBUG
	}
#endif

#ifndef	LOG_DAEMON
	openlog("ntpd", LOG_PID);
#else

#ifndef	LOG_NTP
#define	LOG_NTP	LOG_DAEMON
#endif
	openlog("ntpd", LOG_PID | LOG_NDELAY, LOG_NTP);
#ifdef	DEBUG
	if (debug)
		setlogmask(LOG_UPTO(LOG_DEBUG));
	else
#endif	/* DEBUG */
		setlogmask(LOG_UPTO(LOG_INFO));
#endif	/* LOG_DAEMON */

	syslog(LOG_NOTICE, "%s version $Revision: 3.4.1.9 $", prog_name);
	syslog(LOG_NOTICE, "patchlevel %d", PATCHLEVEL);

#ifdef	DEBUG
	if (debug)
		printf("%s version $Revision: 3.4.1.9 $ patchlevel %d\n",
		       prog_name, PATCHLEVEL);
#endif
	(void) setpriority(PRIO_PROCESS, 0, -10);

#ifdef	NOSWAP
	if (noswap)
		if (plock(PROCLOCK) != 0)  {
			syslog(LOG_ERR, "plock() failed: %m");
#ifdef	DEBUG
			if (debug)
				perror("plock() failed");
#endif
		}
#endif

	servp = getservbyname("ntp", "udp");
	if (servp == NULL) {
		syslog(LOG_CRIT, "udp/ntp: service unknown, using default %d",
		       NTP_PORT);
		(void) create_sockets(htons(NTP_PORT));
	} else
		(void) create_sockets(servp->s_port);


	peer_list.head = peer_list.tail = NULL;
	peer_list.members = 0;

	init_ntp(conf);
	init_kern_vars();
	init_logical_clock();

	/*
	 * Attempt to open for writing the file for storing the drift comp
	 * register.  File must already exist for snapshots to be taken.
	 */
	if ((i = open(driftcomp_file, O_WRONLY|O_CREAT, 0644)) >= 0) {
		drift_fd = i;
	}
	(void) gettimeofday(&tv, (struct timezone *) 0);
	srand(tv.tv_sec);

	FD_ZERO(&tmpmask);
	for (i = 0; i < nintf; i++) {
		FD_SET(addrs[i].fd, &tmpmask);
#ifdef	DEBUG
		if (debug>2) {
			if (addrs[i].if_flags & IFF_BROADCAST)
				printf("Addr %d: %s fd %d %s broadcast %s\n",
				       i, addrs[i].name, addrs[i].fd,
				       ntoa(addrs[i].sin.sin_addr),
				       ntoa(addrs[i].bcast.sin_addr));
			else
				printf("Addr %d: %s fd %d %s\n", i,
				       addrs[i].name, addrs[i].fd,
				       ntoa(addrs[i].sin.sin_addr));
		}
#endif
	}

	(void) signal(SIGINT, finish);
	(void) signal(SIGTERM, finish);
	(void) signal(SIGALRM, tock);
#if	defined(DEBUG) && defined(SIGUSR1) && defined(SIGUSR2)
	(void) signal(SIGUSR1, incdebug);
	(void) signal(SIGUSR2, decdebug);
#endif
	itp->it_interval.tv_sec = (1<<CLOCK_ADJ);
	itp->it_interval.tv_usec = 0;
	itp->it_value.tv_sec = 1;
	itp->it_value.tv_usec = 0;

	/*
	 * Find highest fd in use.  This might save a few microseconds in
	 * the select system call.
	 */
	for (selfds = FD_SETSIZE - 1; selfds; selfds--)
		if (FD_ISSET(selfds, &tmpmask))
			break;
#ifdef	DEBUG
	if (debug > 2)
		printf("Highest fd in use is %d\n", selfds);
	if (!selfds) abort();
#endif
	selfds++;

	(void) setitimer(ITIMER_REAL, itp, (struct itimerval *) 0);

	for (;;) {		/* go into a finite but hopefully very long
				 * loop */
		int nfds;

		readfds = tmpmask;
		nfds = select(selfds, &readfds, (fd_set *) 0, (fd_set *) 0,
						(struct timeval *) 0);
		(void) gettimeofday(&tv, (struct timezone *) 0);

		for(i = 0; i < nintf && nfds; i++) {
			if (!FD_ISSET(addrs[i].fd, &readfds))
				continue;
			addrs[i].uses++;
			dstlen = sizeof(struct sockaddr_in);
			if ((cc = 
			     recvfrom(addrs[i].fd, (char *) pkt, 
				      sizeof(ntpframe), 0, 
				      (struct sockaddr *) dst, &dstlen)) < 0) {

				if (errno != EWOULDBLOCK) {
					syslog("recvfrom: %m");
#ifdef	DEBUG
					if(debug > 2)
						perror("recvfrom");
#endif
				}
				continue;
			}

			if (cc < sizeof(*pkt)) {
#ifdef	DEBUG
				if (debug)
					printf("Runt packet from %s\n",
					       ntoa(dst->sin_addr));
#endif
				continue;
			}

			if (pkt->stratum == INFO_QUERY || 
			    pkt->stratum == INFO_REPLY) {
				query_mode(dst, pkt, i);
				continue;
			}
#ifdef	DEBUG
			if (debug > 3) {
				printf("\nInput ");
				dump_pkt(dst, pkt, NULL);
			}
#endif
			if ((pkt->status & VERSIONMASK) != NTPVERSION_1)
				continue;

			receive(dst, pkt, &tv, i);
		}
		if (ticked) {
			ticked = 0;
			timeout();
		}
	}			/* end of forever loop */
}

struct ntp_peer *
check_peer(dst, sock)
	struct sockaddr_in *dst;
	int sock;
{
	register struct ntp_peer *peer = peer_list.head;

	while (peer != NULL) {
		if ((peer->src.sin_addr.s_addr == dst->sin_addr.s_addr) &&
		    (peer->src.sin_port == dst->sin_port) &&
		    ((peer->sock == sock) || (peer->sock == -1)))
			return peer;
		peer = peer->next;
	}
	return ((struct ntp_peer *) NULL);
}

#ifdef	DEBUG
dump_pkt(dst, pkt, peer)
	struct sockaddr_in *dst;
	struct ntpdata *pkt;
	struct ntp_peer *peer;
{
	struct in_addr clock_host;

	printf("Packet: [%s](%d)\n", inet_ntoa(dst->sin_addr),
	       (int) htons(dst->sin_port));
	printf("Leap %d, version %d, mode %d, poll %d, precision %d stratum %d",