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

	       (pkt->status & LEAPMASK) >> 6, (pkt->status & VERSIONMASK) >> 3,
	       pkt->status & MODEMASK, pkt->ppoll, pkt->precision,
	       pkt->stratum);
	switch (pkt->stratum) {
	case 0:
	case 1:
		printf(" (%.4s)\n", (char *)&pkt->refid);
		break;
	default:
		clock_host.s_addr = (u_long) pkt->refid;
		printf(" [%s]\n", inet_ntoa(clock_host));
		break;
	}
	printf("Synch Dist is %04X.%04X  Synch Dispersion is %04X.%04X\n",
	       ntohs((u_short) pkt->distance.int_part),
	       ntohs((u_short) pkt->distance.fraction),
	       ntohs((u_short) pkt->dispersion.int_part),
	       ntohs((u_short) pkt->dispersion.fraction));
	printf("Reference Timestamp is %08lx.%08lx\n",
	       ntohl(pkt->reftime.int_part),
	       ntohl(pkt->reftime.fraction));
	printf("Originate Timestamp is %08lx.%08lx\n",
	       ntohl(pkt->org.int_part),
	       ntohl(pkt->org.fraction));
	printf("Receive Timestamp is   %08lx.%08lx\n",
	       ntohl(pkt->rec.int_part),
	       ntohl(pkt->rec.fraction));
	printf("Transmit Timestamp is  %08lx.%08lx\n",
	       ntohl(pkt->xmt.int_part),
	       ntohl(pkt->xmt.fraction));
	if(peer != NULL)
		printf("Input Timestamp is     %08lx.%08lx\n",
		       ntohl(peer->rec.int_part),
		       ntohl(peer->rec.fraction));
	putchar('\n');
}
#endif

void
make_new_peer(peer)
	struct ntp_peer *peer;
{
	int i;

	/*
	 * initialize peer data fields 
	 */
	peer->src.sin_family = AF_INET;
	peer->src.sin_port = 0;
	peer->src.sin_addr.s_addr = 0;
	peer->hmode = MODE_SYM_PAS;	/* default: symmetric passive mode */
	peer->flags = 0;
	peer->timer = 1 << NTP_MINPOLL;
	peer->stopwatch = 0;
	peer->hpoll = NTP_MINPOLL;
	double_to_s_fixed(&peer->dispersion, PEER_MAXDISP);
	peer->reach = 0;
	peer->estoffset = 0.0;
	peer->estdelay = 0.0;
	peer->org.int_part = peer->org.fraction = 0;
	peer->rec.int_part = peer->rec.fraction = 0;
	peer->filter.samples = 0;
	for (i = 0; i < NTP_WINDOW; i++) {
		peer->filter.offset[i] = 0.0;
		peer->filter.delay[i] = 0.0;
	}
	peer->pkt_sent = 0;
	peer->pkt_rcvd = 0;
	peer->pkt_dropped = 0;
}

/*
 *  This procedure is called to delete a peer from our list of peers.
 */
void
demobilize(l, peer)
	struct list *l;
	struct ntp_peer *peer;
{
	extern struct ntp_peer dummy_peer;

	if (peer == &dummy_peer)
#ifdef	DEBUG
		abort();
#else
		return;
#endif

#ifdef	DEBUG
	if ((peer->next == NULL && peer->prev == NULL) ||
	    l->tail == NULL || l->head == NULL)
		abort();
#endif

	/* delete only peer in list? */
	if (l->head == l->tail) {
#ifdef	DEBUG
		if (l->head != peer) abort();
#endif
		l->head = l->tail = NULL;
		goto dropit;
	}

	/* delete first peer? */
	if (l->head == peer) {
		l->head = peer->next;
		l->head->prev = NULL;
		goto dropit;
	}

	/* delete last peer? */
	if (l->tail == peer) {
		l->tail = peer->prev;
		l->tail->next = NULL;
		goto dropit;
	}

	/* drop peer in middle */
	peer->prev->next = peer->next;
	peer->next->prev = peer->prev;

 dropit:
#ifdef	DEBUG
	/* just some sanity checking */
	if ((l->members < 0) || 
	    (l->members && l->tail == NULL) ||
	    (l->members == 0 && l->tail != NULL)) {
		syslog(LOG_ERR, "List hosed (demobilize)");
		abort();
	}
	peer->next = peer->prev = NULL;
#endif
	free((char *) peer);
	l->members--;

	return;
}

enqueue(l, peer)
	register struct list *l;
	struct ntp_peer *peer;
{
	l->members++;
	if (l->tail == NULL) {
		/* insertion into empty list */
		l->tail = l->head = peer;
		peer->next = peer->prev = NULL;
		return;
	}

	/* insert at end of list */
	l->tail->next = peer;
	peer->next = NULL;
	peer->prev = l->tail;
	l->tail = peer;
}

/* XXX */
/*
 *  Trivial signal handler.  Assumes you have Berkeley flavored signals which
 *  re-enable themselves.
 */
void 
tock() {
	ticked = 1;
}

void
timeout()
{
	static int periodic = 0;
	register struct ntp_peer *peer = peer_list.head, *next;
#ifndef	XADJTIME2
	extern void adj_host_clock();

	adj_host_clock();
#endif
	/*
	 * Count down sys.hold if necessary.
	 */
	if (sys.hold) {
		if (sys.hold <= (1<<CLOCK_ADJ))
			sys.hold = 0;
		else
			sys.hold -= (1<<CLOCK_ADJ);
	}
	/*
	 * If interval has expired blast off an NTP to that host.
	 */
	while (peer != NULL) {
#ifdef	DEBUG
		if (peer->next == NULL && peer != peer_list.tail) {
			printf("Broken peer list\n");
			syslog(LOG_ERR, "Broken peer list");
			abort();
		}
#endif
		next = peer->next;
		if (peer->reach != 0 || peer->hmode != MODE_SERVER) {
			peer->stopwatch +=(1<<CLOCK_ADJ);
			if (peer->timer <= peer->stopwatch) {
				transmit(peer);
				peer->stopwatch = 0;
			}
		}
		peer = next;
	}

	periodic += (1<<CLOCK_ADJ);
	if (periodic >= 60*60) {
		periodic = 0;
		hourly();
	}

	clock_watchdog += (1 << CLOCK_ADJ);
	if (clock_watchdog >= NTP_MAXAGE) {
		/* woof, woof - barking dogs bite! */
		sys.leap = ALARM;
		if (clock_watchdog < NTP_MAXAGE + (1 << CLOCK_ADJ)) {
			syslog(LOG_ERR,
			       "logical clock adjust timeout (%d seconds)",
			       NTP_MAXAGE);
#ifdef	DEBUG
			if (debug)
			 printf("logical clock adjust timeout (%d seconds)\n",
				NTP_MAXAGE);
#endif
		}
	}

#ifdef	DEBUG
	if (debug)
		(void) fflush(stdout);
#endif
}


/*
 * init_ntp() reads NTP daemon configuration information from disk file.
 */
void
init_ntp(config)
	char *config;
{
	struct sockaddr_in sin;
	char ref_clock[5];
	char name[81];
	FILE *fp;
	int error = FALSE, c;
	struct ntp_peer *peer;
	int precision;
	int stratum;
	int i;
	int debuglevel;
	int stagger = 0;
	double j;
	extern double drift_comp;

	bzero((char *) &sin, sizeof(sin));
	fp = fopen(config, "r");
	if (fp == NULL) {
		fprintf(stderr,"Problem opening NTP initialization file %s\n",
			config);
		syslog(LOG_ERR,"Problem opening NTP initialization file %s",
			config);
		exit(1);
	}

	while (fscanf(fp, "%s", name) != EOF) {	/* read first word of line
						 * and compare to key words */
		if (strcmp(name, "maxpeers") == 0) {
			if (fscanf(fp, "%d", &sys.maxpeers) != 1)
				error = TRUE;
		} else if (strcmp(name, "trusting") == 0) {
			if (fscanf(fp, "%s", name) != 1)
				error = TRUE;
			else {
				if (*name == 'Y' || *name == 'y') {
					trusting = 1;
				} else if (*name == 'N' || *name == 'n') {
					trusting = 0;
				} else
					trusting = atoi(name);
			}
		} else if (strcmp(name, "logclock") == 0) {
			if (fscanf(fp, "%s", name) != 1)
				error = TRUE;
			else {
				if (*name == 'Y' || *name == 'y') {
					logstats = 1;
				} else if (*name == 'N' || *name == 'n') {
					logstats = 0;
				} else
					logstats = atoi(name);
			}
		} else if (strcmp(name, "driftfile") == 0) {
			if (fscanf(fp, "%s", name) != 1)
				error = TRUE;
			else {
				if (driftcomp_file = malloc(strlen(name)+1))
					strcpy(driftcomp_file, name);
			}
		} else if (strcmp(name, "waytoobig") == 0 ||
			   strcmp(name, "setthreshold") == 0) {
			if (fscanf(fp, "%s", name) != 1)
				error = TRUE;
			else {
				if (strcmp(name, "any") == 0)
					WayTooBig = 10e15;
				else
					WayTooBig = atof(name);
			}
		} else if (strncmp(name, "debuglevel", 5) == 0) {
			if (fscanf(fp, "%d", &debuglevel) != 1)
				error = TRUE;
#ifdef	DEBUG
			else debug += debuglevel;
#endif
		} else if (strcmp(name, "stratum") == 0) {
			fprintf(stderr, "Obsolete command 'stratum'\n");
			error = TRUE;
		} else if (strcmp(name, "precision") == 0) {
			if (fscanf(fp, "%d", &precision) != 1)
				error = TRUE;
			else sys.precision = (char) precision;
#ifdef	SETTICKADJ
		} else if (strcmp(name, "tickadj") == 0) {
			if (fscanf(fp, "%d", &i) != 1)
				error = TRUE;
			else tickadj = i;
		} else if (strcmp(name, "settickadj") == 0) {
			if (fscanf(fp, "%s", name) != 1)
				error = TRUE;
			else {
				if (*name == 'Y' || *name == 'y') {
					dotickadj = 1;
				} else if (*name == 'N' || *name == 'n') {
					dotickadj = 0;
				} else
					dotickadj = atoi(name);
			}
#endif
#ifdef	NOSWAP
		} else if (strcmp(name, "noswap") == 0) {
			noswap = 1;
#endif
#ifdef	BROADCAST_NTP
		} else if (strcmp(name, "broadcast") == 0) {
			if (fscanf(fp, "%s", name) != 1) {
				error = TRUE;
				goto skipit;
			}
			for (i = 0; i < nintf; i++)
				if (strcmp(addrs[i].name, name) == 0)
					break;
			if (i == nintf) {
				syslog(LOG_ERR, "config file: %s not a known interface");
				error = TRUE;
				goto skipit;
			}
			if ((addrs[i].if_flags & IFF_BROADCAST) == 0) {
				syslog(LOG_ERR, "config file: %s doesn't support broadcast", name);
				error = TRUE;
				goto skipit;
			}
			if (peer = check_peer(&addrs[i].bcast, -1)) {
				syslog(LOG_ERR, "config file: duplicate broadcast for %s",
				       name);
				error = TRUE;
				goto skipit;
			}
			peer = (struct ntp_peer *) malloc(sizeof(struct ntp_peer));
			if (peer == NULL) {
				error = TRUE;
				syslog(LOG_ERR, "No memory");
				goto skipit;
			}
			make_new_peer(peer);
			peer->flags = PEER_FL_BCAST;
			peer->hmode = MODE_BROADCAST;
			peer->src = addrs[i].bcast;
			peer->sock = i;
#endif	/* BROADCAST_NTP */
		} else if ((strcmp(name, "peer") == 0) || 
			   (strcmp(name, "passive") == 0) ||
			   (strcmp(name, "server") == 0)) {
			int mode = 0;

			if (strcmp(name, "peer") == 0) {
				mode = MODE_SYM_ACT;
			} else if (strcmp(name, "server") == 0) {
				mode = MODE_CLIENT;
			} else if (strcmp(name, "passive") == 0) {
				mode = MODE_SYM_PAS;
			} else {
				printf("can't happen\n");
				abort();
			}
			if (fscanf(fp, "%s", name) != 1)
				error = TRUE;
#ifdef REFCLOCK
			else if (name[0] == '/') {
				int stratum, precision;
				char clk_type[20];

				if (fscanf(fp, "%4s", ref_clock) != 1) {
					error = TRUE;
					syslog(LOG_ERR, "reference id missing");
					goto skipit;
				}
				if (fscanf(fp, "%4d", &stratum) != 1) {
					error = TRUE;
					syslog(LOG_ERR, "reference stratum missing");
					goto skipit;
				}
				if (fscanf(fp, "%4d", &precision) != 1) {
					error = TRUE;
					syslog(LOG_ERR, "reference precision missing");
					goto skipit;
				}
				if (fscanf(fp, "%19s", clk_type) != 1) {
					error = TRUE;
					syslog(LOG_ERR, "reference type missing");
					goto skipit;
				}

				if((i = init_clock(name, clk_type)) < 0) {
					/* If we could not initialize clock line */
#ifdef DEBUG
					if (debug)
						printf("Could not init reference source %s (type %s)\n",
							name, clk_type);
					else
#endif DEBUG
						syslog(LOG_ERR, "Could not init reference source %s (type %s)",
							name, clk_type);
					error = TRUE;
					goto skipit;
				}
				peer = (struct ntp_peer *)
					malloc(sizeof(struct ntp_peer));
				if (peer == NULL) {
					close(i);
					error = TRUE;
					goto skipit;
				}
				make_new_peer(peer);
				ref_clock[4] = 0;
				(void) strncpy((char *) &peer->refid,
						ref_clock, 4);
				peer->flags = PEER_FL_CONFIG|PEER_FL_REFCLOCK;
				peer->hmode = MODE_SYM_ACT;
				peer->stopwatch = stagger;
				stagger += (1<<CLOCK_ADJ);
				peer->flags |= PEER_FL_SYNC;
				peer->sock = i;
				peer->stratum = stratum;
				peer->precision = precision;
				clear(peer);
				enqueue(&peer_list, peer);
				if (debug > 1)
					printf("Peer %s mode %d refid %.4s stratum %d precision %d\n",
					       name,
					       peer->hmode,
					       (char *)&peer->refid,
					       stratum, precision);
				transmit(peer);	/* head start for REFCLOCK */
			}
#endif REFCLOCK
			else if (GetHostName(name, &sin) == 0)
				syslog(LOG_ERR, "%s: unknown host", name);
			else {
				for (i=0; i<nintf; i++)
					if (addrs[i].sin.sin_addr.s_addr ==
					    sin.sin_addr.s_addr)
						goto skipit;

				if (servp)
					sin.sin_port = servp->s_port;
				else
					sin.sin_port = htons(NTP_PORT);

				peer = check_peer(&sin, -1);
				if (peer == NULL) {
					peer = (struct ntp_peer *)
						malloc(sizeof(struct ntp_peer));
					if (peer == NULL)
						error = TRUE;
					else {
						make_new_peer(peer);
						peer->flags = PEER_FL_CONFIG;
						switch (mode) {
						case MODE_SYM_ACT:	/* "peer" */
							peer->hmode = MODE_SYM_ACT;
							peer->stopwatch = stagger;
							stagger += (1<<CLOCK_ADJ);
							peer->flags |= PEER_FL_SYNC;
							break;
						case MODE_CLIENT:	/* "server" */
							peer->hmode = MODE_CLIENT;
							peer->stopwatch = stagger;