xref: /netbsd-src/external/bsd/ntp/dist/sntp/main.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: main.c,v 1.16 2018/04/07 00:19:53 christos Exp $	*/
2 
3 #include <config.h>
4 
5 #include <event2/util.h>
6 #include <event2/event.h>
7 
8 #include "ntp_workimpl.h"
9 #ifdef WORK_THREAD
10 # include <event2/thread.h>
11 #endif
12 
13 #include "main.h"
14 #include "ntp_libopts.h"
15 #include "kod_management.h"
16 #include "networking.h"
17 #include "utilities.h"
18 #include "log.h"
19 #include "libntp.h"
20 
21 
22 int shutting_down;
23 int time_derived;
24 int time_adjusted;
25 int n_pending_dns = 0;
26 int n_pending_ntp = 0;
27 int ai_fam_pref = AF_UNSPEC;
28 int ntpver = 4;
29 double steplimit = -1;
30 SOCKET sock4 = -1;		/* Socket for IPv4 */
31 SOCKET sock6 = -1;		/* Socket for IPv6 */
32 /*
33 ** BCAST *must* listen on port 123 (by default), so we can only
34 ** use the UCST sockets (above) if they too are using port 123
35 */
36 SOCKET bsock4 = -1;		/* Broadcast Socket for IPv4 */
37 SOCKET bsock6 = -1;		/* Broadcast Socket for IPv6 */
38 struct event_base *base;
39 struct event *ev_sock4;
40 struct event *ev_sock6;
41 struct event *ev_worker_timeout;
42 struct event *ev_xmt_timer;
43 
44 struct dns_ctx {
45 	const char *	name;
46 	int		flags;
47 #define CTX_BCST	0x0001
48 #define CTX_UCST	0x0002
49 #define CTX_xCST	0x0003
50 #define CTX_CONC	0x0004
51 #define CTX_unused	0xfffd
52 	int		key_id;
53 	struct timeval	timeout;
54 	struct key *	key;
55 };
56 
57 typedef struct sent_pkt_tag sent_pkt;
58 struct sent_pkt_tag {
59 	sent_pkt *		link;
60 	struct dns_ctx *	dctx;
61 	sockaddr_u		addr;
62 	time_t			stime;
63 	int			done;
64 	struct pkt		x_pkt;
65 };
66 
67 typedef struct xmt_ctx_tag xmt_ctx;
68 struct xmt_ctx_tag {
69 	xmt_ctx *		link;
70 	SOCKET			sock;
71 	time_t			sched;
72 	sent_pkt *		spkt;
73 };
74 
75 struct timeval	gap;
76 xmt_ctx *	xmt_q;
77 struct key *	keys = NULL;
78 int		response_timeout;
79 struct timeval	response_tv;
80 struct timeval	start_tv;
81 /* check the timeout at least once per second */
82 struct timeval	wakeup_tv = { 0, 888888 };
83 
84 sent_pkt *	fam_listheads[2];
85 #define v4_pkts_list	(fam_listheads[0])
86 #define v6_pkts_list	(fam_listheads[1])
87 
88 static union {
89 	struct pkt pkt;
90 	char   buf[LEN_PKT_NOMAC + NTP_MAXEXTEN + MAX_MAC_LEN];
91 } rbuf;
92 
93 #define r_pkt  rbuf.pkt
94 
95 #ifdef HAVE_DROPROOT
96 int droproot;			/* intres imports these */
97 int root_dropped;
98 #endif
99 u_long current_time;		/* libntp/authkeys.c */
100 
101 void open_sockets(void);
102 void handle_lookup(const char *name, int flags);
103 void sntp_addremove_fd(int fd, int is_pipe, int remove_it);
104 void worker_timeout(evutil_socket_t, short, void *);
105 void worker_resp_cb(evutil_socket_t, short, void *);
106 void sntp_name_resolved(int, int, void *, const char *, const char *,
107 			const struct addrinfo *,
108 			const struct addrinfo *);
109 void queue_xmt(SOCKET sock, struct dns_ctx *dctx, sent_pkt *spkt,
110 	       u_int xmt_delay);
111 void xmt_timer_cb(evutil_socket_t, short, void *ptr);
112 void xmt(xmt_ctx *xctx);
113 int  check_kod(const struct addrinfo *ai);
114 void timeout_query(sent_pkt *);
115 void timeout_queries(void);
116 void sock_cb(evutil_socket_t, short, void *);
117 void check_exit_conditions(void);
118 void sntp_libevent_log_cb(int, const char *);
119 void set_li_vn_mode(struct pkt *spkt, char leap, char version, char mode);
120 int  set_time(double offset);
121 void dec_pending_ntp(const char *, sockaddr_u *);
122 int  libevent_version_ok(void);
123 int  gettimeofday_cached(struct event_base *b, struct timeval *tv);
124 
125 
126 /*
127  * The actual main function.
128  */
129 int
130 sntp_main (
131 	int argc,
132 	char **argv,
133 	const char *sntpVersion
134 	)
135 {
136 	int			i;
137 	int			exitcode;
138 	int			optct;
139 	struct event_config *	evcfg;
140 
141 	/* Initialize logging system - sets up progname */
142 	sntp_init_logging(argv[0]);
143 
144 	if (!libevent_version_ok())
145 		exit(EX_SOFTWARE);
146 
147 	init_lib();
148 	init_auth();
149 
150 	optct = ntpOptionProcess(&sntpOptions, argc, argv);
151 	argc -= optct;
152 	argv += optct;
153 
154 
155 	debug = OPT_VALUE_SET_DEBUG_LEVEL;
156 
157 	TRACE(2, ("init_lib() done, %s%s\n",
158 		  (ipv4_works)
159 		      ? "ipv4_works "
160 		      : "",
161 		  (ipv6_works)
162 		      ? "ipv6_works "
163 		      : ""));
164 	ntpver = OPT_VALUE_NTPVERSION;
165 	steplimit = OPT_VALUE_STEPLIMIT / 1e3;
166 	gap.tv_usec = max(0, OPT_VALUE_GAP * 1000);
167 	gap.tv_usec = min(gap.tv_usec, 999999);
168 
169 	if (HAVE_OPT(LOGFILE))
170 		open_logfile(OPT_ARG(LOGFILE));
171 
172 	msyslog(LOG_INFO, "%s", sntpVersion);
173 
174 	if (0 == argc && !HAVE_OPT(BROADCAST) && !HAVE_OPT(CONCURRENT)) {
175 		printf("%s: Must supply at least one of -b hostname, -c hostname, or hostname.\n",
176 		       progname);
177 		exit(EX_USAGE);
178 	}
179 
180 
181 	/*
182 	** Eventually, we probably want:
183 	** - separate bcst and ucst timeouts (why?)
184 	** - multiple --timeout values in the commandline
185 	*/
186 
187 	response_timeout = OPT_VALUE_TIMEOUT;
188 	response_tv.tv_sec = response_timeout;
189 	response_tv.tv_usec = 0;
190 
191 	/* IPv6 available? */
192 	if (isc_net_probeipv6() != ISC_R_SUCCESS) {
193 		ai_fam_pref = AF_INET;
194 		TRACE(1, ("No ipv6 support available, forcing ipv4\n"));
195 	} else {
196 		/* Check for options -4 and -6 */
197 		if (HAVE_OPT(IPV4))
198 			ai_fam_pref = AF_INET;
199 		else if (HAVE_OPT(IPV6))
200 			ai_fam_pref = AF_INET6;
201 	}
202 
203 	/* TODO: Parse config file if declared */
204 
205 	/*
206 	** Init the KOD system.
207 	** For embedded systems with no writable filesystem,
208 	** -K /dev/null can be used to disable KoD storage.
209 	*/
210 	kod_init_kod_db(OPT_ARG(KOD), FALSE);
211 
212 	/* HMS: Check and see what happens if KEYFILE doesn't exist */
213 	auth_init(OPT_ARG(KEYFILE), &keys);
214 
215 	/*
216 	** Considering employing a variable that prevents functions of doing
217 	** anything until everything is initialized properly
218 	**
219 	** HMS: What exactly does the above mean?
220 	*/
221 	event_set_log_callback(&sntp_libevent_log_cb);
222 	if (debug > 0)
223 		event_enable_debug_mode();
224 #ifdef WORK_THREAD
225 	evthread_use_pthreads();
226 	/* we use libevent from main thread only, locks should be academic */
227 	if (debug > 0)
228 		evthread_enable_lock_debuging();
229 #endif
230 	evcfg = event_config_new();
231 	if (NULL == evcfg) {
232 		printf("%s: event_config_new() failed!\n", progname);
233 		return -1;
234 	}
235 #ifndef HAVE_SOCKETPAIR
236 	event_config_require_features(evcfg, EV_FEATURE_FDS);
237 #endif
238 	/* all libevent calls are from main thread */
239 	/* event_config_set_flag(evcfg, EVENT_BASE_FLAG_NOLOCK); */
240 	base = event_base_new_with_config(evcfg);
241 	event_config_free(evcfg);
242 	if (NULL == base) {
243 		printf("%s: event_base_new() failed!\n", progname);
244 		return -1;
245 	}
246 
247 	/* wire into intres resolver */
248 	worker_per_query = TRUE;
249 	addremove_io_fd = &sntp_addremove_fd;
250 
251 	open_sockets();
252 
253 	if (HAVE_OPT(BROADCAST)) {
254 		int		cn = STACKCT_OPT(  BROADCAST );
255 		const char **	cp = STACKLST_OPT( BROADCAST );
256 
257 		while (cn-- > 0) {
258 			handle_lookup(*cp, CTX_BCST);
259 			cp++;
260 		}
261 	}
262 
263 	if (HAVE_OPT(CONCURRENT)) {
264 		int		cn = STACKCT_OPT( CONCURRENT );
265 		const char **	cp = STACKLST_OPT( CONCURRENT );
266 
267 		while (cn-- > 0) {
268 			handle_lookup(*cp, CTX_UCST | CTX_CONC);
269 			cp++;
270 		}
271 	}
272 
273 	for (i = 0; i < argc; ++i)
274 		handle_lookup(argv[i], CTX_UCST);
275 
276 	gettimeofday_cached(base, &start_tv);
277 	event_base_dispatch(base);
278 	event_base_free(base);
279 
280 	if (!time_adjusted &&
281 	    (ENABLED_OPT(STEP) || ENABLED_OPT(SLEW)))
282 		exitcode = 1;
283 	else
284 		exitcode = 0;
285 
286 	return exitcode;
287 }
288 
289 
290 /*
291 ** open sockets and make them non-blocking
292 */
293 void
294 open_sockets(
295 	void
296 	)
297 {
298 	sockaddr_u	name;
299 
300 	if (-1 == sock4) {
301 		sock4 = socket(PF_INET, SOCK_DGRAM, 0);
302 		if (-1 == sock4) {
303 			/* error getting a socket */
304 			msyslog(LOG_ERR, "open_sockets: socket(PF_INET) failed: %m");
305 			exit(1);
306 		}
307 		/* Make it non-blocking */
308 		make_socket_nonblocking(sock4);
309 
310 		/* Let's try using a wildcard... */
311 		ZERO(name);
312 		AF(&name) = AF_INET;
313 		SET_ADDR4N(&name, INADDR_ANY);
314 		SET_PORT(&name, (HAVE_OPT(USERESERVEDPORT) ? 123 : 0));
315 
316 		if (-1 == bind(sock4, &name.sa,
317 			       SOCKLEN(&name))) {
318 			msyslog(LOG_ERR, "open_sockets: bind(sock4) failed: %m");
319 			exit(1);
320 		}
321 
322 		/* Register an NTP callback for recv/timeout */
323 		ev_sock4 = event_new(base, sock4,
324 				     EV_TIMEOUT | EV_READ | EV_PERSIST,
325 				     &sock_cb, NULL);
326 		if (NULL == ev_sock4) {
327 			msyslog(LOG_ERR,
328 				"open_sockets: event_new(base, sock4) failed!");
329 		} else {
330 			event_add(ev_sock4, &wakeup_tv);
331 		}
332 	}
333 
334 	/* We may not always have IPv6... */
335 	if (-1 == sock6 && ipv6_works) {
336 		sock6 = socket(PF_INET6, SOCK_DGRAM, 0);
337 		if (-1 == sock6 && ipv6_works) {
338 			/* error getting a socket */
339 			msyslog(LOG_ERR, "open_sockets: socket(PF_INET6) failed: %m");
340 			exit(1);
341 		}
342 		/* Make it non-blocking */
343 		make_socket_nonblocking(sock6);
344 
345 		/* Let's try using a wildcard... */
346 		ZERO(name);
347 		AF(&name) = AF_INET6;
348 		SET_ADDR6N(&name, in6addr_any);
349 		SET_PORT(&name, (HAVE_OPT(USERESERVEDPORT) ? 123 : 0));
350 
351 		if (-1 == bind(sock6, &name.sa,
352 			       SOCKLEN(&name))) {
353 			msyslog(LOG_ERR, "open_sockets: bind(sock6) failed: %m");
354 			exit(1);
355 		}
356 		/* Register an NTP callback for recv/timeout */
357 		ev_sock6 = event_new(base, sock6,
358 				     EV_TIMEOUT | EV_READ | EV_PERSIST,
359 				     &sock_cb, NULL);
360 		if (NULL == ev_sock6) {
361 			msyslog(LOG_ERR,
362 				"open_sockets: event_new(base, sock6) failed!");
363 		} else {
364 			event_add(ev_sock6, &wakeup_tv);
365 		}
366 	}
367 
368 	return;
369 }
370 
371 
372 /*
373 ** handle_lookup
374 */
375 void
376 handle_lookup(
377 	const char *name,
378 	int flags
379 	)
380 {
381 	struct addrinfo	hints;	/* Local copy is OK */
382 	struct dns_ctx *ctx;
383 	char *		name_copy;
384 	size_t		name_sz;
385 	size_t		octets;
386 
387 	TRACE(1, ("handle_lookup(%s,%#x)\n", name, flags));
388 
389 	ZERO(hints);
390 	hints.ai_family = ai_fam_pref;
391 	hints.ai_flags = AI_CANONNAME | Z_AI_NUMERICSERV;
392 	/*
393 	** Unless we specify a socktype, we'll get at least two
394 	** entries for each address: one for TCP and one for
395 	** UDP. That's not what we want.
396 	*/
397 	hints.ai_socktype = SOCK_DGRAM;
398 	hints.ai_protocol = IPPROTO_UDP;
399 
400 	name_sz = 1 + strlen(name);
401 	octets = sizeof(*ctx) + name_sz;	// Space for a ctx and the name
402 	ctx = emalloc_zero(octets);		// ctx at ctx[0]
403 	name_copy = (char *)(ctx + 1);		// Put the name at ctx[1]
404 	memcpy(name_copy, name, name_sz);	// copy the name to ctx[1]
405 	ctx->name = name_copy;			// point to it...
406 	ctx->flags = flags;
407 	ctx->timeout = response_tv;
408 	ctx->key = NULL;
409 
410 	/* The following should arguably be passed in... */
411 	if (ENABLED_OPT(AUTHENTICATION)) {
412 		ctx->key_id = OPT_VALUE_AUTHENTICATION;
413 		get_key(ctx->key_id, &ctx->key);
414 		if (NULL == ctx->key) {
415 			fprintf(stderr, "%s: Authentication with keyID %d requested, but no matching keyID found in <%s>!\n",
416 				progname, ctx->key_id, OPT_ARG(KEYFILE));
417 			exit(1);
418 		}
419 	} else {
420 		ctx->key_id = -1;
421 	}
422 
423 	++n_pending_dns;
424 	getaddrinfo_sometime(name, "123", &hints, 0,
425 			     &sntp_name_resolved, ctx);
426 }
427 
428 
429 /*
430 ** DNS Callback:
431 ** - For each IP:
432 ** - - open a socket
433 ** - - increment n_pending_ntp
434 ** - - send a request if this is a Unicast callback
435 ** - - queue wait for response
436 ** - decrement n_pending_dns
437 */
438 void
439 sntp_name_resolved(
440 	int			rescode,
441 	int			gai_errno,
442 	void *			context,
443 	const char *		name,
444 	const char *		service,
445 	const struct addrinfo *	hints,
446 	const struct addrinfo *	addr
447 	)
448 {
449 	struct dns_ctx *	dctx;
450 	sent_pkt *		spkt;
451 	const struct addrinfo *	ai;
452 	SOCKET			sock;
453 	u_int			xmt_delay_v4;
454 	u_int			xmt_delay_v6;
455 	u_int			xmt_delay;
456 	size_t			octets;
457 
458 	xmt_delay_v4 = 0;
459 	xmt_delay_v6 = 0;
460 	dctx = context;
461 	if (rescode) {
462 #ifdef EAI_SYSTEM
463 		if (EAI_SYSTEM == rescode) {
464 			errno = gai_errno;
465 			mfprintf(stderr, "%s lookup error %m\n",
466 				 dctx->name);
467 		} else
468 #endif
469 			fprintf(stderr, "%s lookup error %s\n",
470 				dctx->name, gai_strerror(rescode));
471 	} else {
472 		TRACE(3, ("%s [%s]\n", dctx->name,
473 			  (addr->ai_canonname != NULL)
474 			      ? addr->ai_canonname
475 			      : ""));
476 
477 		for (ai = addr; ai != NULL; ai = ai->ai_next) {
478 
479 			if (check_kod(ai))
480 				continue;
481 
482 			switch (ai->ai_family) {
483 
484 			case AF_INET:
485 				sock = sock4;
486 				xmt_delay = xmt_delay_v4;
487 				xmt_delay_v4++;
488 				break;
489 
490 			case AF_INET6:
491 				if (!ipv6_works)
492 					continue;
493 
494 				sock = sock6;
495 				xmt_delay = xmt_delay_v6;
496 				xmt_delay_v6++;
497 				break;
498 
499 			default:
500 				msyslog(LOG_ERR, "sntp_name_resolved: unexpected ai_family: %d",
501 					ai->ai_family);
502 				exit(1);
503 				break;
504 			}
505 
506 			/*
507 			** We're waiting for a response for either unicast
508 			** or broadcast, so...
509 			*/
510 			++n_pending_ntp;
511 
512 			/* If this is for a unicast IP, queue a request */
513 			if (dctx->flags & CTX_UCST) {
514 				spkt = emalloc_zero(sizeof(*spkt));
515 				spkt->dctx = dctx;
516 				octets = min(ai->ai_addrlen, sizeof(spkt->addr));
517 				memcpy(&spkt->addr, ai->ai_addr, octets);
518 				queue_xmt(sock, dctx, spkt, xmt_delay);
519 			}
520 		}
521 	}
522 	/* n_pending_dns really should be >0 here... */
523 	--n_pending_dns;
524 	check_exit_conditions();
525 }
526 
527 
528 /*
529 ** queue_xmt
530 */
531 void
532 queue_xmt(
533 	SOCKET			sock,
534 	struct dns_ctx *	dctx,
535 	sent_pkt *		spkt,
536 	u_int			xmt_delay
537 	)
538 {
539 	sockaddr_u *	dest;
540 	sent_pkt **	pkt_listp;
541 	sent_pkt *	match;
542 	xmt_ctx *	xctx;
543 	struct timeval	start_cb;
544 	struct timeval	delay;
545 
546 	dest = &spkt->addr;
547 	if (IS_IPV6(dest))
548 		pkt_listp = &v6_pkts_list;
549 	else
550 		pkt_listp = &v4_pkts_list;
551 
552 	/* reject attempts to add address already listed */
553 	for (match = *pkt_listp; match != NULL; match = match->link) {
554 		if (ADDR_PORT_EQ(&spkt->addr, &match->addr)) {
555 			if (strcasecmp(spkt->dctx->name,
556 				       match->dctx->name))
557 				printf("%s %s duplicate address from %s ignored.\n",
558 				       sptoa(&match->addr),
559 				       match->dctx->name,
560 				       spkt->dctx->name);
561 			else
562 				printf("%s %s, duplicate address ignored.\n",
563 				       sptoa(&match->addr),
564 				       match->dctx->name);
565 			dec_pending_ntp(spkt->dctx->name, &spkt->addr);
566 			free(spkt);
567 			return;
568 		}
569 	}
570 
571 	LINK_SLIST(*pkt_listp, spkt, link);
572 
573 	xctx = emalloc_zero(sizeof(*xctx));
574 	xctx->sock = sock;
575 	xctx->spkt = spkt;
576 	gettimeofday_cached(base, &start_cb);
577 	xctx->sched = start_cb.tv_sec + (2 * xmt_delay);
578 
579 	LINK_SORT_SLIST(xmt_q, xctx, (xctx->sched < L_S_S_CUR()->sched),
580 			link, xmt_ctx);
581 	if (xmt_q == xctx) {
582 		/*
583 		 * The new entry is the first scheduled.  The timer is
584 		 * either not active or is set for the second xmt
585 		 * context in xmt_q.
586 		 */
587 		if (NULL == ev_xmt_timer)
588 			ev_xmt_timer = event_new(base, INVALID_SOCKET,
589 						 EV_TIMEOUT,
590 						 &xmt_timer_cb, NULL);
591 		if (NULL == ev_xmt_timer) {
592 			msyslog(LOG_ERR,
593 				"queue_xmt: event_new(base, -1, EV_TIMEOUT) failed!");
594 			exit(1);
595 		}
596 		ZERO(delay);
597 		if (xctx->sched > start_cb.tv_sec)
598 			delay.tv_sec = xctx->sched - start_cb.tv_sec;
599 		event_add(ev_xmt_timer, &delay);
600 		TRACE(2, ("queue_xmt: xmt timer for %u usec\n",
601 			  (u_int)delay.tv_usec));
602 	}
603 }
604 
605 
606 /*
607 ** xmt_timer_cb
608 */
609 void
610 xmt_timer_cb(
611 	evutil_socket_t	fd,
612 	short		what,
613 	void *		ctx
614 	)
615 {
616 	struct timeval	start_cb;
617 	struct timeval	delay;
618 	xmt_ctx *	x;
619 
620 	UNUSED_ARG(fd);
621 	UNUSED_ARG(ctx);
622 	DEBUG_INSIST(EV_TIMEOUT == what);
623 
624 	if (NULL == xmt_q || shutting_down)
625 		return;
626 	gettimeofday_cached(base, &start_cb);
627 	if (xmt_q->sched <= start_cb.tv_sec) {
628 		UNLINK_HEAD_SLIST(x, xmt_q, link);
629 		TRACE(2, ("xmt_timer_cb: at .%6.6u -> %s\n",
630 			  (u_int)start_cb.tv_usec, stoa(&x->spkt->addr)));
631 		xmt(x);
632 		free(x);
633 		if (NULL == xmt_q)
634 			return;
635 	}
636 	if (xmt_q->sched <= start_cb.tv_sec) {
637 		event_add(ev_xmt_timer, &gap);
638 		TRACE(2, ("xmt_timer_cb: at .%6.6u gap %6.6u\n",
639 			  (u_int)start_cb.tv_usec,
640 			  (u_int)gap.tv_usec));
641 	} else {
642 		delay.tv_sec = xmt_q->sched - start_cb.tv_sec;
643 		delay.tv_usec = 0;
644 		event_add(ev_xmt_timer, &delay);
645 		TRACE(2, ("xmt_timer_cb: at .%6.6u next %ld seconds\n",
646 			  (u_int)start_cb.tv_usec,
647 			  (long)delay.tv_sec));
648 	}
649 }
650 
651 
652 /*
653 ** xmt()
654 */
655 void
656 xmt(
657 	xmt_ctx *	xctx
658 	)
659 {
660 	SOCKET		sock = xctx->sock;
661 	struct dns_ctx *dctx = xctx->spkt->dctx;
662 	sent_pkt *	spkt = xctx->spkt;
663 	sockaddr_u *	dst = &spkt->addr;
664 	struct timeval	tv_xmt;
665 	struct pkt	x_pkt;
666 	size_t		pkt_len;
667 	int		sent;
668 
669 	if (0 != gettimeofday(&tv_xmt, NULL)) {
670 		msyslog(LOG_ERR,
671 			"xmt: gettimeofday() failed: %m");
672 		exit(1);
673 	}
674 	tv_xmt.tv_sec += JAN_1970;
675 
676 	pkt_len = generate_pkt(&x_pkt, &tv_xmt, dctx->key_id,
677 			       dctx->key);
678 
679 	sent = sendpkt(sock, dst, &x_pkt, pkt_len);
680 	if (sent) {
681 		/* Save the packet we sent... */
682 		memcpy(&spkt->x_pkt, &x_pkt, min(sizeof(spkt->x_pkt),
683 		       pkt_len));
684 		spkt->stime = tv_xmt.tv_sec - JAN_1970;
685 
686 		TRACE(2, ("xmt: %lx.%6.6u %s %s\n", (u_long)tv_xmt.tv_sec,
687 			  (u_int)tv_xmt.tv_usec, dctx->name, stoa(dst)));
688 	} else {
689 		dec_pending_ntp(dctx->name, dst);
690 	}
691 
692 	return;
693 }
694 
695 
696 /*
697  * timeout_queries() -- give up on unrequited NTP queries
698  */
699 void
700 timeout_queries(void)
701 {
702 	struct timeval	start_cb;
703 	u_int		idx;
704 	sent_pkt *	head;
705 	sent_pkt *	spkt;
706 	sent_pkt *	spkt_next;
707 	long		age;
708 	int didsomething = 0;
709 
710 	TRACE(3, ("timeout_queries: called to check %u items\n",
711 		  (unsigned)COUNTOF(fam_listheads)));
712 
713 	gettimeofday_cached(base, &start_cb);
714 	for (idx = 0; idx < COUNTOF(fam_listheads); idx++) {
715 		head = fam_listheads[idx];
716 		for (spkt = head; spkt != NULL; spkt = spkt_next) {
717 			char xcst;
718 
719 			didsomething = 1;
720 			switch (spkt->dctx->flags & CTX_xCST) {
721 			    case CTX_BCST:
722 				xcst = 'B';
723 				break;
724 
725 			    case CTX_UCST:
726 				xcst = 'U';
727 				break;
728 
729 			    default:
730 				INSIST(!"spkt->dctx->flags neither UCST nor BCST");
731 				break;
732 			}
733 
734 			spkt_next = spkt->link;
735 			if (0 == spkt->stime || spkt->done)
736 				continue;
737 			age = start_cb.tv_sec - spkt->stime;
738 			TRACE(3, ("%s %s %cCST age %ld\n",
739 				  stoa(&spkt->addr),
740 				  spkt->dctx->name, xcst, age));
741 			if (age > response_timeout)
742 				timeout_query(spkt);
743 		}
744 	}
745 	// Do we care about didsomething?
746 	TRACE(3, ("timeout_queries: didsomething is %d, age is %ld\n",
747 		  didsomething, (long) (start_cb.tv_sec - start_tv.tv_sec)));
748 	if (start_cb.tv_sec - start_tv.tv_sec > response_timeout) {
749 		TRACE(3, ("timeout_queries: bail!\n"));
750 		event_base_loopexit(base, NULL);
751 		shutting_down = TRUE;
752 	}
753 }
754 
755 
756 void dec_pending_ntp(
757 	const char *	name,
758 	sockaddr_u *	server
759 	)
760 {
761 	if (n_pending_ntp > 0) {
762 		--n_pending_ntp;
763 		check_exit_conditions();
764 	} else {
765 		INSIST(0 == n_pending_ntp);
766 		TRACE(1, ("n_pending_ntp was zero before decrement for %s\n",
767 			  hostnameaddr(name, server)));
768 	}
769 }
770 
771 
772 void timeout_query(
773 	sent_pkt *	spkt
774 	)
775 {
776 	sockaddr_u *	server;
777 	char		xcst;
778 
779 
780 	switch (spkt->dctx->flags & CTX_xCST) {
781 	    case CTX_BCST:
782 		xcst = 'B';
783 		break;
784 
785 	    case CTX_UCST:
786 		xcst = 'U';
787 		break;
788 
789 	    default:
790 		INSIST(!"spkt->dctx->flags neither UCST nor BCST");
791 		break;
792 	}
793 	spkt->done = TRUE;
794 	server = &spkt->addr;
795 	msyslog(LOG_INFO, "%s no %cCST response after %d seconds",
796 		hostnameaddr(spkt->dctx->name, server), xcst,
797 		response_timeout);
798 	dec_pending_ntp(spkt->dctx->name, server);
799 	return;
800 }
801 
802 
803 /*
804 ** check_kod
805 */
806 int
807 check_kod(
808 	const struct addrinfo *	ai
809 	)
810 {
811 	char *hostname;
812 	struct kod_entry *reason;
813 
814 	/* Is there a KoD on file for this address? */
815 	hostname = addrinfo_to_str(ai);
816 	TRACE(2, ("check_kod: checking <%s>\n", hostname));
817 	if (search_entry(hostname, &reason)) {
818 		printf("prior KoD for %s, skipping.\n",
819 			hostname);
820 		free(reason);
821 		free(hostname);
822 
823 		return 1;
824 	}
825 	free(hostname);
826 
827 	return 0;
828 }
829 
830 
831 /*
832 ** Socket readable/timeout Callback:
833 ** Read in the packet
834 ** Unicast:
835 ** - close socket
836 ** - decrement n_pending_ntp
837 ** - If packet is good, set the time and "exit"
838 ** Broadcast:
839 ** - If packet is good, set the time and "exit"
840 */
841 void
842 sock_cb(
843 	evutil_socket_t fd,
844 	short what,
845 	void *ptr
846 	)
847 {
848 	sockaddr_u	sender;
849 	sockaddr_u *	psau;
850 	sent_pkt **	p_pktlist;
851 	sent_pkt *	spkt;
852 	int		rpktl;
853 	int		rc;
854 
855 	INSIST(sock4 == fd || sock6 == fd);
856 
857 	TRACE(3, ("sock_cb: event on sock%s:%s%s%s%s\n",
858 		  (fd == sock6)
859 		      ? "6"
860 		      : "4",
861 		  (what & EV_TIMEOUT) ? " timeout" : "",
862 		  (what & EV_READ)    ? " read" : "",
863 		  (what & EV_WRITE)   ? " write" : "",
864 		  (what & EV_SIGNAL)  ? " signal" : ""));
865 
866 	if (!(EV_READ & what)) {
867 		if (EV_TIMEOUT & what)
868 			timeout_queries();
869 
870 		return;
871 	}
872 
873 	/* Read in the packet */
874 	rpktl = recvdata(fd, &sender, &rbuf, sizeof(rbuf));
875 	if (rpktl < 0) {
876 		msyslog(LOG_DEBUG, "recvfrom error %m");
877 		return;
878 	}
879 
880 	if (sock6 == fd)
881 		p_pktlist = &v6_pkts_list;
882 	else
883 		p_pktlist = &v4_pkts_list;
884 
885 	for (spkt = *p_pktlist; spkt != NULL; spkt = spkt->link) {
886 		psau = &spkt->addr;
887 		if (SOCK_EQ(&sender, psau))
888 			break;
889 	}
890 	if (NULL == spkt) {
891 		msyslog(LOG_WARNING,
892 			"Packet from unexpected source %s dropped",
893 			sptoa(&sender));
894 		return;
895 	}
896 
897 	TRACE(1, ("sock_cb: %s %s\n", spkt->dctx->name,
898 		  sptoa(&sender)));
899 
900 	rpktl = process_pkt(&r_pkt, &sender, rpktl, MODE_SERVER,
901 			    &spkt->x_pkt, "sock_cb");
902 
903 	TRACE(2, ("sock_cb: process_pkt returned %d\n", rpktl));
904 
905 	/* If this is a Unicast packet, one down ... */
906 	if (!spkt->done && (CTX_UCST & spkt->dctx->flags)) {
907 		dec_pending_ntp(spkt->dctx->name, &spkt->addr);
908 		spkt->done = TRUE;
909 	}
910 
911 
912 	/* If the packet is good, set the time and we're all done */
913 	rc = handle_pkt(rpktl, &r_pkt, &spkt->addr, spkt->dctx->name);
914 	if (0 != rc)
915 		TRACE(1, ("sock_cb: handle_pkt() returned %d\n", rc));
916 	check_exit_conditions();
917 }
918 
919 
920 /*
921  * check_exit_conditions()
922  *
923  * If sntp has a reply, ask the event loop to stop after this round of
924  * callbacks, unless --wait was used.
925  */
926 void
927 check_exit_conditions(void)
928 {
929 	if ((0 == n_pending_ntp && 0 == n_pending_dns) ||
930 	    (time_derived && !HAVE_OPT(WAIT))) {
931 		event_base_loopexit(base, NULL);
932 		shutting_down = TRUE;
933 	} else {
934 		TRACE(2, ("%d NTP and %d name queries pending\n",
935 			  n_pending_ntp, n_pending_dns));
936 	}
937 }
938 
939 
940 /*
941  * sntp_addremove_fd() is invoked by the intres blocking worker code
942  * to read from a pipe, or to stop same.
943  */
944 void sntp_addremove_fd(
945 	int	fd,
946 	int	is_pipe,
947 	int	remove_it
948 	)
949 {
950 	u_int		idx;
951 	blocking_child *c;
952 	struct event *	ev;
953 
954 #ifdef HAVE_SOCKETPAIR
955 	if (is_pipe) {
956 		/* sntp only asks for EV_FEATURE_FDS without HAVE_SOCKETPAIR */
957 		msyslog(LOG_ERR, "fatal: pipes not supported on systems with socketpair()");
958 		exit(1);
959 	}
960 #endif
961 
962 	c = NULL;
963 	for (idx = 0; idx < blocking_children_alloc; idx++) {
964 		c = blocking_children[idx];
965 		if (NULL == c)
966 			continue;
967 		if (fd == c->resp_read_pipe)
968 			break;
969 	}
970 	if (idx == blocking_children_alloc)
971 		return;
972 
973 	if (remove_it) {
974 		ev = c->resp_read_ctx;
975 		c->resp_read_ctx = NULL;
976 		event_del(ev);
977 		event_free(ev);
978 
979 		return;
980 	}
981 
982 	ev = event_new(base, fd, EV_READ | EV_PERSIST,
983 		       &worker_resp_cb, c);
984 	if (NULL == ev) {
985 		msyslog(LOG_ERR,
986 			"sntp_addremove_fd: event_new(base, fd) failed!");
987 		return;
988 	}
989 	c->resp_read_ctx = ev;
990 	event_add(ev, NULL);
991 }
992 
993 
994 /* called by forked intres child to close open descriptors */
995 #ifdef WORK_FORK
996 void
997 kill_asyncio(
998 	int	startfd
999 	)
1000 {
1001 	if (INVALID_SOCKET != sock4) {
1002 		closesocket(sock4);
1003 		sock4 = INVALID_SOCKET;
1004 	}
1005 	if (INVALID_SOCKET != sock6) {
1006 		closesocket(sock6);
1007 		sock6 = INVALID_SOCKET;
1008 	}
1009 	if (INVALID_SOCKET != bsock4) {
1010 		closesocket(sock4);
1011 		sock4 = INVALID_SOCKET;
1012 	}
1013 	if (INVALID_SOCKET != bsock6) {
1014 		closesocket(sock6);
1015 		sock6 = INVALID_SOCKET;
1016 	}
1017 }
1018 #endif
1019 
1020 
1021 /*
1022  * worker_resp_cb() is invoked when resp_read_pipe is readable.
1023  */
1024 void
1025 worker_resp_cb(
1026 	evutil_socket_t	fd,
1027 	short		what,
1028 	void *		ctx	/* blocking_child * */
1029 	)
1030 {
1031 	blocking_child *	c;
1032 
1033 	DEBUG_INSIST(EV_READ & what);
1034 	c = ctx;
1035 	DEBUG_INSIST(fd == c->resp_read_pipe);
1036 	process_blocking_resp(c);
1037 }
1038 
1039 
1040 /*
1041  * intres_timeout_req(s) is invoked in the parent to schedule an idle
1042  * timeout to fire in s seconds, if not reset earlier by a call to
1043  * intres_timeout_req(0), which clears any pending timeout.  When the
1044  * timeout expires, worker_idle_timer_fired() is invoked (again, in the
1045  * parent).
1046  *
1047  * sntp and ntpd each provide implementations adapted to their timers.
1048  */
1049 void
1050 intres_timeout_req(
1051 	u_int	seconds		/* 0 cancels */
1052 	)
1053 {
1054 	struct timeval	tv_to;
1055 
1056 	if (NULL == ev_worker_timeout) {
1057 		ev_worker_timeout = event_new(base, -1,
1058 					      EV_TIMEOUT | EV_PERSIST,
1059 					      &worker_timeout, NULL);
1060 		DEBUG_INSIST(NULL != ev_worker_timeout);
1061 	} else {
1062 		event_del(ev_worker_timeout);
1063 	}
1064 	if (0 == seconds)
1065 		return;
1066 	tv_to.tv_sec = seconds;
1067 	tv_to.tv_usec = 0;
1068 	event_add(ev_worker_timeout, &tv_to);
1069 }
1070 
1071 
1072 void
1073 worker_timeout(
1074 	evutil_socket_t	fd,
1075 	short		what,
1076 	void *		ctx
1077 	)
1078 {
1079 	UNUSED_ARG(fd);
1080 	UNUSED_ARG(ctx);
1081 
1082 	DEBUG_REQUIRE(EV_TIMEOUT & what);
1083 	worker_idle_timer_fired();
1084 }
1085 
1086 
1087 void
1088 sntp_libevent_log_cb(
1089 	int		severity,
1090 	const char *	msg
1091 	)
1092 {
1093 	int		level;
1094 
1095 	switch (severity) {
1096 
1097 	default:
1098 	case _EVENT_LOG_DEBUG:
1099 		level = LOG_DEBUG;
1100 		break;
1101 
1102 	case _EVENT_LOG_MSG:
1103 		level = LOG_NOTICE;
1104 		break;
1105 
1106 	case _EVENT_LOG_WARN:
1107 		level = LOG_WARNING;
1108 		break;
1109 
1110 	case _EVENT_LOG_ERR:
1111 		level = LOG_ERR;
1112 		break;
1113 	}
1114 
1115 	msyslog(level, "%s", msg);
1116 }
1117 
1118 
1119 int
1120 generate_pkt (
1121 	struct pkt *x_pkt,
1122 	const struct timeval *tv_xmt,
1123 	int key_id,
1124 	struct key *pkt_key
1125 	)
1126 {
1127 	l_fp	xmt_fp;
1128 	int	pkt_len;
1129 	int	mac_size;
1130 
1131 	pkt_len = LEN_PKT_NOMAC;
1132 	ZERO(*x_pkt);
1133 	TVTOTS(tv_xmt, &xmt_fp);
1134 	HTONL_FP(&xmt_fp, &x_pkt->xmt);
1135 	x_pkt->stratum = STRATUM_TO_PKT(STRATUM_UNSPEC);
1136 	x_pkt->ppoll = 8;
1137 	/* FIXME! Modus broadcast + adr. check -> bdr. pkt */
1138 	set_li_vn_mode(x_pkt, LEAP_NOTINSYNC, ntpver, 3);
1139 	if (debug > 0) {
1140 		printf("generate_pkt: key_id %d, key pointer %p\n", key_id, pkt_key);
1141 	}
1142 	if (pkt_key != NULL) {
1143 		x_pkt->exten[0] = htonl(key_id);
1144 		mac_size = make_mac(x_pkt, pkt_len, MAX_MDG_LEN,
1145 				    pkt_key, (char *)&x_pkt->exten[1]);
1146 		if (mac_size > 0)
1147 			pkt_len += mac_size + KEY_MAC_LEN;
1148 #ifdef DEBUG
1149 		if (debug > 0) {
1150 			printf("generate_pkt: mac_size is %d\n", mac_size);
1151 		}
1152 #endif
1153 
1154 	}
1155 	return pkt_len;
1156 }
1157 
1158 
1159 int
1160 handle_pkt(
1161 	int		rpktl,
1162 	struct pkt *	rpkt,
1163 	sockaddr_u *	host,
1164 	const char *	hostname
1165 	)
1166 {
1167 	char		disptxt[32];
1168 	const char *	addrtxt;
1169 	struct timeval	tv_dst;
1170 	int		cnt;
1171 	int		sw_case;
1172 	int		digits;
1173 	int		stratum;
1174 	char *		ref;
1175 	char *		ts_str;
1176 	const char *	leaptxt;
1177 	double		offset;
1178 	double		precision;
1179 	double		synch_distance;
1180 	char *		p_SNTP_PRETEND_TIME;
1181 	time_t		pretend_time;
1182 #if SIZEOF_TIME_T == 8
1183 	long long	ll;
1184 #else
1185 	long		l;
1186 #endif
1187 
1188 	ts_str = NULL;
1189 
1190 	if (rpktl > 0)
1191 		sw_case = 1;
1192 	else
1193 		sw_case = rpktl;
1194 
1195 	switch (sw_case) {
1196 
1197 	case SERVER_UNUSEABLE:
1198 		return -1;
1199 		break;
1200 
1201 	case PACKET_UNUSEABLE:
1202 		break;
1203 
1204 	case SERVER_AUTH_FAIL:
1205 		break;
1206 
1207 	case KOD_DEMOBILIZE:
1208 		/* Received a DENY or RESTR KOD packet */
1209 		addrtxt = stoa(host);
1210 		ref = (char *)&rpkt->refid;
1211 		add_entry(addrtxt, ref);
1212 		msyslog(LOG_WARNING, "KOD code %c%c%c%c from %s %s",
1213 			ref[0], ref[1], ref[2], ref[3], addrtxt, hostname);
1214 		break;
1215 
1216 	case KOD_RATE:
1217 		/*
1218 		** Hmm...
1219 		** We should probably call add_entry() with an
1220 		** expiration timestamp of several seconds in the future,
1221 		** and back-off even more if we get more RATE responses.
1222 		*/
1223 		break;
1224 
1225 	case 1:
1226 		TRACE(3, ("handle_pkt: %d bytes from %s %s\n",
1227 			  rpktl, stoa(host), hostname));
1228 
1229 		gettimeofday_cached(base, &tv_dst);
1230 
1231 		p_SNTP_PRETEND_TIME = getenv("SNTP_PRETEND_TIME");
1232 		if (p_SNTP_PRETEND_TIME) {
1233 			pretend_time = 0;
1234 #if SIZEOF_TIME_T == 4
1235 			if (1 == sscanf(p_SNTP_PRETEND_TIME, "%ld", &l))
1236 				pretend_time = (time_t)l;
1237 #elif SIZEOF_TIME_T == 8
1238 			if (1 == sscanf(p_SNTP_PRETEND_TIME, "%lld", &ll))
1239 				pretend_time = (time_t)ll;
1240 #else
1241 # include "GRONK: unexpected value for SIZEOF_TIME_T"
1242 #endif
1243 			if (0 != pretend_time)
1244 				tv_dst.tv_sec = pretend_time;
1245 		}
1246 
1247 		offset_calculation(rpkt, rpktl, &tv_dst, &offset,
1248 				   &precision, &synch_distance);
1249 		time_derived = TRUE;
1250 
1251 		for (digits = 0; (precision *= 10.) < 1.; ++digits)
1252 			/* empty */ ;
1253 		if (digits > 6)
1254 			digits = 6;
1255 
1256 		ts_str = tv_to_str(&tv_dst);
1257 		stratum = rpkt->stratum;
1258 		if (0 == stratum)
1259 				stratum = 16;
1260 
1261 		if (synch_distance > 0.) {
1262 			cnt = snprintf(disptxt, sizeof(disptxt),
1263 				       " +/- %f", synch_distance);
1264 			if ((size_t)cnt >= sizeof(disptxt))
1265 				snprintf(disptxt, sizeof(disptxt),
1266 					 "ERROR %d >= %d", cnt,
1267 					 (int)sizeof(disptxt));
1268 		} else {
1269 			disptxt[0] = '\0';
1270 		}
1271 
1272 		switch (PKT_LEAP(rpkt->li_vn_mode)) {
1273 		    case LEAP_NOWARNING:
1274 		    	leaptxt = "no-leap";
1275 			break;
1276 		    case LEAP_ADDSECOND:
1277 		    	leaptxt = "add-leap";
1278 			break;
1279 		    case LEAP_DELSECOND:
1280 		    	leaptxt = "del-leap";
1281 			break;
1282 		    case LEAP_NOTINSYNC:
1283 		    	leaptxt = "unsync";
1284 			break;
1285 		    default:
1286 		    	leaptxt = "LEAP-ERROR";
1287 			break;
1288 		}
1289 
1290 		msyslog(LOG_INFO, "%s %+.*f%s %s s%d %s%s", ts_str,
1291 			digits, offset, disptxt,
1292 			hostnameaddr(hostname, host), stratum,
1293 			leaptxt,
1294 			(time_adjusted)
1295 			    ? " [excess]"
1296 			    : "");
1297 		free(ts_str);
1298 
1299 		if (p_SNTP_PRETEND_TIME)
1300 			return 0;
1301 
1302 		if (!time_adjusted &&
1303 		    (ENABLED_OPT(STEP) || ENABLED_OPT(SLEW)))
1304 			return set_time(offset);
1305 
1306 		return EX_OK;
1307 	}
1308 
1309 	return 1;
1310 }
1311 
1312 
1313 void
1314 offset_calculation(
1315 	struct pkt *rpkt,
1316 	int rpktl,
1317 	struct timeval *tv_dst,
1318 	double *offset,
1319 	double *precision,
1320 	double *synch_distance
1321 	)
1322 {
1323 	l_fp p_rec, p_xmt, p_ref, p_org, tmp, dst;
1324 	u_fp p_rdly, p_rdsp;
1325 	double t21, t34, delta;
1326 
1327 	/* Convert timestamps from network to host byte order */
1328 	p_rdly = NTOHS_FP(rpkt->rootdelay);
1329 	p_rdsp = NTOHS_FP(rpkt->rootdisp);
1330 	NTOHL_FP(&rpkt->reftime, &p_ref);
1331 	NTOHL_FP(&rpkt->org, &p_org);
1332 	NTOHL_FP(&rpkt->rec, &p_rec);
1333 	NTOHL_FP(&rpkt->xmt, &p_xmt);
1334 
1335 	*precision = LOGTOD(rpkt->precision);
1336 
1337 	TRACE(3, ("offset_calculation: LOGTOD(rpkt->precision): %f\n", *precision));
1338 
1339 	/* Compute offset etc. */
1340 	tmp = p_rec;
1341 	L_SUB(&tmp, &p_org);
1342 	LFPTOD(&tmp, t21);
1343 	TVTOTS(tv_dst, &dst);
1344 	dst.l_ui += JAN_1970;
1345 	tmp = p_xmt;
1346 	L_SUB(&tmp, &dst);
1347 	LFPTOD(&tmp, t34);
1348 	*offset = (t21 + t34) / 2.;
1349 	delta = t21 - t34;
1350 
1351 	// synch_distance is:
1352 	// (peer->delay + peer->rootdelay) / 2 + peer->disp
1353 	// + peer->rootdisp + clock_phi * (current_time - peer->update)
1354 	// + peer->jitter;
1355 	//
1356 	// and peer->delay = fabs(peer->offset - p_offset) * 2;
1357 	// and peer->offset needs history, so we're left with
1358 	// p_offset = (t21 + t34) / 2.;
1359 	// peer->disp = 0; (we have no history to augment this)
1360 	// clock_phi = 15e-6;
1361 	// peer->jitter = LOGTOD(sys_precision); (we have no history to augment this)
1362 	// and ntp_proto.c:set_sys_tick_precision() should get us sys_precision.
1363 	//
1364 	// so our answer seems to be:
1365 	//
1366 	// (fabs(t21 + t34) + peer->rootdelay) / 3.
1367 	// + 0 (peer->disp)
1368 	// + peer->rootdisp
1369 	// + 15e-6 (clock_phi)
1370 	// + LOGTOD(sys_precision)
1371 
1372 	INSIST( FPTOD(p_rdly) >= 0. );
1373 #if 1
1374 	*synch_distance = (fabs(t21 + t34) + FPTOD(p_rdly)) / 3.
1375 		+ 0.
1376 		+ FPTOD(p_rdsp)
1377 		+ 15e-6
1378 		+ 0.	/* LOGTOD(sys_precision) when we can get it */
1379 		;
1380 	INSIST( *synch_distance >= 0. );
1381 #else
1382 	*synch_distance = (FPTOD(p_rdly) + FPTOD(p_rdsp))/2.0;
1383 #endif
1384 
1385 #ifdef DEBUG
1386 	if (debug > 3) {
1387 		printf("sntp rootdelay: %f\n", FPTOD(p_rdly));
1388 		printf("sntp rootdisp: %f\n", FPTOD(p_rdsp));
1389 		printf("sntp syncdist: %f\n", *synch_distance);
1390 
1391 		pkt_output(rpkt, rpktl, stdout);
1392 
1393 		printf("sntp offset_calculation: rpkt->reftime:\n");
1394 		l_fp_output(&p_ref, stdout);
1395 		printf("sntp offset_calculation: rpkt->org:\n");
1396 		l_fp_output(&p_org, stdout);
1397 		printf("sntp offset_calculation: rpkt->rec:\n");
1398 		l_fp_output(&p_rec, stdout);
1399 		printf("sntp offset_calculation: rpkt->xmt:\n");
1400 		l_fp_output(&p_xmt, stdout);
1401 	}
1402 #endif
1403 
1404 	TRACE(3, ("sntp offset_calculation:\trec - org t21: %.6f\n"
1405 		  "\txmt - dst t34: %.6f\tdelta: %.6f\toffset: %.6f\n",
1406 		  t21, t34, delta, *offset));
1407 
1408 	return;
1409 }
1410 
1411 
1412 
1413 /* Compute the 8 bits for li_vn_mode */
1414 void
1415 set_li_vn_mode (
1416 	struct pkt *spkt,
1417 	char leap,
1418 	char version,
1419 	char mode
1420 	)
1421 {
1422 	if (leap > 3) {
1423 		msyslog(LOG_DEBUG, "set_li_vn_mode: leap > 3, using max. 3");
1424 		leap = 3;
1425 	}
1426 
1427 	if ((unsigned char)version > 7) {
1428 		msyslog(LOG_DEBUG, "set_li_vn_mode: version < 0 or > 7, using 4");
1429 		version = 4;
1430 	}
1431 
1432 	if (mode > 7) {
1433 		msyslog(LOG_DEBUG, "set_li_vn_mode: mode > 7, using client mode 3");
1434 		mode = 3;
1435 	}
1436 
1437 	spkt->li_vn_mode  = leap << 6;
1438 	spkt->li_vn_mode |= version << 3;
1439 	spkt->li_vn_mode |= mode;
1440 }
1441 
1442 
1443 /*
1444 ** set_time applies 'offset' to the local clock.
1445 */
1446 int
1447 set_time(
1448 	double offset
1449 	)
1450 {
1451 	int rc;
1452 
1453 	if (time_adjusted)
1454 		return EX_OK;
1455 
1456 	/*
1457 	** If we can step but we cannot slew, then step.
1458 	** If we can step or slew and and |offset| > steplimit, then step.
1459 	*/
1460 	if (ENABLED_OPT(STEP) &&
1461 	    (   !ENABLED_OPT(SLEW)
1462 	     || (ENABLED_OPT(SLEW) && (fabs(offset) > steplimit))
1463 	    )) {
1464 		rc = step_systime(offset);
1465 
1466 		/* If there was a problem, can we rely on errno? */
1467 		if (1 == rc)
1468 			time_adjusted = TRUE;
1469 		return (time_adjusted)
1470 			   ? EX_OK
1471 			   : 1;
1472 		/*
1473 		** In case of error, what should we use?
1474 		** EX_UNAVAILABLE?
1475 		** EX_OSERR?
1476 		** EX_NOPERM?
1477 		*/
1478 	}
1479 
1480 	if (ENABLED_OPT(SLEW)) {
1481 		rc = adj_systime(offset);
1482 
1483 		/* If there was a problem, can we rely on errno? */
1484 		if (1 == rc)
1485 			time_adjusted = TRUE;
1486 		return (time_adjusted)
1487 			   ? EX_OK
1488 			   : 1;
1489 		/*
1490 		** In case of error, what should we use?
1491 		** EX_UNAVAILABLE?
1492 		** EX_OSERR?
1493 		** EX_NOPERM?
1494 		*/
1495 	}
1496 
1497 	return EX_SOFTWARE;
1498 }
1499 
1500 
1501 int
1502 libevent_version_ok(void)
1503 {
1504 	ev_uint32_t v_compile_maj;
1505 	ev_uint32_t v_run_maj;
1506 
1507 	v_compile_maj = LIBEVENT_VERSION_NUMBER & 0xffff0000;
1508 	v_run_maj = event_get_version_number() & 0xffff0000;
1509 	if (v_compile_maj != v_run_maj) {
1510 		fprintf(stderr,
1511 			"Incompatible libevent versions: have %s, built with %s\n",
1512 			event_get_version(),
1513 			LIBEVENT_VERSION);
1514 		return 0;
1515 	}
1516 	return 1;
1517 }
1518 
1519 /*
1520  * gettimeofday_cached()
1521  *
1522  * Clones the event_base_gettimeofday_cached() interface but ensures the
1523  * times are always on the gettimeofday() 1970 scale.  Older libevent 2
1524  * sometimes used gettimeofday(), sometimes the since-system-start
1525  * clock_gettime(CLOCK_MONOTONIC), depending on the platform.
1526  *
1527  * It is not cleanly possible to tell which timescale older libevent is
1528  * using.
1529  *
1530  * The strategy involves 1 hour thresholds chosen to be far longer than
1531  * the duration of a round of libevent callbacks, which share a cached
1532  * start-of-round time.  First compare the last cached time with the
1533  * current gettimeofday() time.  If they are within one hour, libevent
1534  * is using the proper timescale so leave the offset 0.  Otherwise,
1535  * compare libevent's cached time and the current time on the monotonic
1536  * scale.  If they are within an hour, libevent is using the monotonic
1537  * scale so calculate the offset to add to such times to bring them to
1538  * gettimeofday()'s scale.
1539  */
1540 int
1541 gettimeofday_cached(
1542 	struct event_base *	b,
1543 	struct timeval *	caller_tv
1544 	)
1545 {
1546 #if defined(_EVENT_HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
1547 	static struct event_base *	cached_b;
1548 	static struct timeval		cached;
1549 	static struct timeval		adj_cached;
1550 	static struct timeval		offset;
1551 	static int			offset_ready;
1552 	struct timeval			latest;
1553 	struct timeval			systemt;
1554 	struct timespec			ts;
1555 	struct timeval			mono;
1556 	struct timeval			diff;
1557 	int				cgt_rc;
1558 	int				gtod_rc;
1559 
1560 	event_base_gettimeofday_cached(b, &latest);
1561 	if (b == cached_b &&
1562 	    !memcmp(&latest, &cached, sizeof(latest))) {
1563 		*caller_tv = adj_cached;
1564 		return 0;
1565 	}
1566 	cached = latest;
1567 	cached_b = b;
1568 	if (!offset_ready) {
1569 		cgt_rc = clock_gettime(CLOCK_MONOTONIC, &ts);
1570 		gtod_rc = gettimeofday(&systemt, NULL);
1571 		if (0 != gtod_rc) {
1572 			msyslog(LOG_ERR,
1573 				"%s: gettimeofday() error %m",
1574 				progname);
1575 			exit(1);
1576 		}
1577 		diff = sub_tval(systemt, latest);
1578 		if (debug > 1)
1579 			printf("system minus cached %+ld.%06ld\n",
1580 			       (long)diff.tv_sec, (long)diff.tv_usec);
1581 		if (0 != cgt_rc || labs((long)diff.tv_sec) < 3600) {
1582 			/*
1583 			 * Either use_monotonic == 0, or this libevent
1584 			 * has been repaired.  Leave offset at zero.
1585 			 */
1586 		} else {
1587 			mono.tv_sec = ts.tv_sec;
1588 			mono.tv_usec = ts.tv_nsec / 1000;
1589 			diff = sub_tval(latest, mono);
1590 			if (debug > 1)
1591 				printf("cached minus monotonic %+ld.%06ld\n",
1592 				       (long)diff.tv_sec, (long)diff.tv_usec);
1593 			if (labs((long)diff.tv_sec) < 3600) {
1594 				/* older libevent2 using monotonic */
1595 				offset = sub_tval(systemt, mono);
1596 				TRACE(1, ("%s: Offsetting libevent CLOCK_MONOTONIC times  by %+ld.%06ld\n",
1597 					 "gettimeofday_cached",
1598 					 (long)offset.tv_sec,
1599 					 (long)offset.tv_usec));
1600 			}
1601 		}
1602 		offset_ready = TRUE;
1603 	}
1604 	adj_cached = add_tval(cached, offset);
1605 	*caller_tv = adj_cached;
1606 
1607 	return 0;
1608 #else
1609 	return event_base_gettimeofday_cached(b, caller_tv);
1610 #endif
1611 }
1612 
1613