xref: /netbsd-src/external/bsd/ntp/dist/sntp/main.c (revision eabc0478de71e4e011a5b4e0392741e01d491794)
1 /*	$NetBSD: main.c,v 1.19 2024/08/18 20:47:20 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 #ifdef HAVE_SYSEXITS_H
14 # include <sysexits.h>
15 #endif
16 
17 #include "main.h"
18 #include "ntp_libopts.h"
19 #include "kod_management.h"
20 #include "networking.h"
21 #include "utilities.h"
22 #include "log.h"
23 #include "libntp.h"
24 
25 extern const char *progname;
26 
27 int shutting_down;
28 int time_derived;
29 int time_adjusted;
30 int n_pending_dns = 0;
31 int n_pending_ntp = 0;
32 int ai_fam_pref = AF_UNSPEC;
33 int ntpver = 4;
34 double steplimit = -1;
35 SOCKET sock4 = -1;		/* Socket for IPv4 */
36 SOCKET sock6 = -1;		/* Socket for IPv6 */
37 /*
38 ** BCAST *must* listen on port 123 (by default), so we can only
39 ** use the UCST sockets (above) if they too are using port 123
40 */
41 SOCKET bsock4 = -1;		/* Broadcast Socket for IPv4 */
42 SOCKET bsock6 = -1;		/* Broadcast Socket for IPv6 */
43 struct event_base *base;
44 struct event *ev_sock4;
45 struct event *ev_sock6;
46 struct event *ev_worker_timeout;
47 struct event *ev_xmt_timer;
48 
49 struct dns_ctx {
50 	const char *	name;
51 	int		flags;
52 #define CTX_BCST	0x0001
53 #define CTX_UCST	0x0002
54 #define CTX_xCST	0x0003
55 #define CTX_CONC	0x0004
56 #define CTX_unused	0xfffd
57 	int		key_id;
58 	struct timeval	timeout;
59 	struct key *	key;
60 };
61 
62 typedef struct sent_pkt_tag sent_pkt;
63 struct sent_pkt_tag {
64 	sent_pkt *		link;
65 	struct dns_ctx *	dctx;
66 	sockaddr_u		addr;
67 	time_t			stime;
68 	int			done;
69 	struct pkt		x_pkt;
70 };
71 
72 typedef struct xmt_ctx_tag xmt_ctx;
73 struct xmt_ctx_tag {
74 	xmt_ctx *		link;
75 	SOCKET			sock;
76 	time_t			sched;
77 	sent_pkt *		spkt;
78 };
79 
80 struct timeval	gap;
81 xmt_ctx *	xmt_q;
82 struct key *	keys = NULL;
83 int		response_timeout;
84 struct timeval	response_tv;
85 struct timeval	start_tv;
86 /* check the timeout at least once per second */
87 struct timeval	wakeup_tv = { 0, 888888 };
88 
89 sent_pkt *	fam_listheads[2];
90 #define v4_pkts_list	(fam_listheads[0])
91 #define v6_pkts_list	(fam_listheads[1])
92 
93 static union {
94 	struct pkt pkt;
95 	char   buf[LEN_PKT_NOMAC + NTP_MAXEXTEN + MAX_MAC_LEN];
96 } rbuf;
97 
98 #define r_pkt  rbuf.pkt
99 
100 #ifdef HAVE_DROPROOT
101 int droproot;			/* intres imports these */
102 int root_dropped;
103 #endif
104 u_long current_time;		/* libntp/authkeys.c */
105 
106 void open_sockets(void);
107 void handle_lookup(const char *name, int flags);
108 void sntp_addremove_fd(int fd, int is_pipe, int remove_it);
109 void worker_timeout(evutil_socket_t, short, void *);
110 void worker_resp_cb(evutil_socket_t, short, void *);
111 void sntp_name_resolved(int, int, void *, const char *, const char *,
112 			const struct addrinfo *,
113 			const struct addrinfo *);
114 void queue_xmt(SOCKET sock, struct dns_ctx *dctx, sent_pkt *spkt,
115 	       u_int xmt_delay);
116 void xmt_timer_cb(evutil_socket_t, short, void *ptr);
117 void xmt(xmt_ctx *xctx);
118 int  check_kod(const struct addrinfo *ai);
119 void timeout_query(sent_pkt *);
120 void timeout_queries(void);
121 void sock_cb(evutil_socket_t, short, void *);
122 void check_exit_conditions(void);
123 void sntp_libevent_log_cb(int, const char *);
124 void set_li_vn_mode(struct pkt *spkt, char leap, char version, char mode);
125 int  set_time(double offset);
126 void dec_pending_ntp(const char *, sockaddr_u *);
127 int  libevent_version_ok(void);
128 int  gettimeofday_cached(struct event_base *b, struct timeval *tv);
129 
130 
131 /*
132  * The actual main function.
133  */
134 int
135 sntp_main (
136 	int argc,
137 	char **argv,
138 	const char *sntpVersion
139 	)
140 {
141 	int			i;
142 	int			exitcode;
143 	int			optct;
144 	struct event_config *	evcfg;
145 
146 	/* Initialize logging system - sets up progname */
147 	sntp_init_logging(argv[0]);
148 
149 	if (!libevent_version_ok())
150 		exit(EX_SOFTWARE);
151 
152 	init_lib();
153 	init_auth();
154 
155 	optct = ntpOptionProcess(&sntpOptions, argc, argv);
156 	argc -= optct;
157 	argv += optct;
158 
159 
160 	debug = OPT_VALUE_SET_DEBUG_LEVEL;
161 
162 	TRACE(2, ("init_lib() done, %s%s\n",
163 		  (ipv4_works)
164 		      ? "ipv4_works "
165 		      : "",
166 		  (ipv6_works)
167 		      ? "ipv6_works "
168 		      : ""));
169 	ntpver = OPT_VALUE_NTPVERSION;
170 	steplimit = OPT_VALUE_STEPLIMIT / 1e3;
171 	gap.tv_usec = max(0, OPT_VALUE_GAP * 1000);
172 	gap.tv_usec = min(gap.tv_usec, 999999);
173 
174 	if (HAVE_OPT(LOGFILE))
175 		open_logfile(OPT_ARG(LOGFILE));
176 
177 	msyslog(LOG_INFO, "%s", sntpVersion);
178 
179 	if (0 == argc && !HAVE_OPT(BROADCAST) && !HAVE_OPT(CONCURRENT)) {
180 		printf("%s: Must supply at least one of -b hostname, -c hostname, or hostname.\n",
181 		       progname);
182 		exit(EX_USAGE);
183 	}
184 
185 
186 	/*
187 	** Eventually, we probably want:
188 	** - separate bcst and ucst timeouts (why?)
189 	** - multiple --timeout values in the commandline
190 	*/
191 
192 	response_timeout = OPT_VALUE_TIMEOUT;
193 	response_tv.tv_sec = response_timeout;
194 	response_tv.tv_usec = 0;
195 
196 	/* IPv6 available? */
197 	if (isc_net_probeipv6() != ISC_R_SUCCESS) {
198 		ai_fam_pref = AF_INET;
199 		TRACE(1, ("No ipv6 support available, forcing ipv4\n"));
200 	} else {
201 		/* Check for options -4 and -6 */
202 		if (HAVE_OPT(IPV4))
203 			ai_fam_pref = AF_INET;
204 		else if (HAVE_OPT(IPV6))
205 			ai_fam_pref = AF_INET6;
206 	}
207 
208 	/* TODO: Parse config file if declared */
209 
210 	/*
211 	** Init the KOD system.
212 	** For embedded systems with no writable filesystem,
213 	** -K /dev/null can be used to disable KoD storage.
214 	*/
215 	kod_init_kod_db(OPT_ARG(KOD), FALSE);
216 
217 	/* HMS: Check and see what happens if KEYFILE doesn't exist */
218 	auth_init(OPT_ARG(KEYFILE), &keys);
219 
220 	/*
221 	** Considering employing a variable that prevents functions of doing
222 	** anything until everything is initialized properly
223 	**
224 	** HMS: What exactly does the above mean?
225 	*/
226 	event_set_log_callback(&sntp_libevent_log_cb);
227 	if (debug > 0)
228 		event_enable_debug_mode();
229 #ifdef WORK_THREAD
230 	evthread_use_pthreads();
231 	/* we use libevent from main thread only, locks should be academic */
232 	if (debug > 0)
233 		evthread_enable_lock_debuging();
234 #endif
235 	evcfg = event_config_new();
236 	if (NULL == evcfg) {
237 		printf("%s: event_config_new() failed!\n", progname);
238 		return -1;
239 	}
240 #ifndef HAVE_SOCKETPAIR
241 	event_config_require_features(evcfg, EV_FEATURE_FDS);
242 #endif
243 	/* all libevent calls are from main thread */
244 	/* event_config_set_flag(evcfg, EVENT_BASE_FLAG_NOLOCK); */
245 	base = event_base_new_with_config(evcfg);
246 	event_config_free(evcfg);
247 	if (NULL == base) {
248 		printf("%s: event_base_new() failed!\n", progname);
249 		return -1;
250 	}
251 
252 	/* wire into intres resolver */
253 	worker_per_query = TRUE;
254 	addremove_io_fd = &sntp_addremove_fd;
255 
256 	open_sockets();
257 
258 	if (HAVE_OPT(BROADCAST)) {
259 		int		cn = STACKCT_OPT(  BROADCAST );
260 		const char **	cp = STACKLST_OPT( BROADCAST );
261 
262 		while (cn-- > 0) {
263 			handle_lookup(*cp, CTX_BCST);
264 			cp++;
265 		}
266 	}
267 
268 	if (HAVE_OPT(CONCURRENT)) {
269 		int		cn = STACKCT_OPT( CONCURRENT );
270 		const char **	cp = STACKLST_OPT( CONCURRENT );
271 
272 		while (cn-- > 0) {
273 			handle_lookup(*cp, CTX_UCST | CTX_CONC);
274 			cp++;
275 		}
276 	}
277 
278 	for (i = 0; i < argc; ++i)
279 		handle_lookup(argv[i], CTX_UCST);
280 
281 	gettimeofday_cached(base, &start_tv);
282 	event_base_dispatch(base);
283 	event_base_free(base);
284 
285 	if (!time_adjusted &&
286 	    (ENABLED_OPT(STEP) || ENABLED_OPT(SLEW)))
287 		exitcode = 1;
288 	else
289 		exitcode = 0;
290 
291 	return exitcode;
292 }
293 
294 
295 /*
296 ** open sockets and make them non-blocking
297 */
298 void
299 open_sockets(
300 	void
301 	)
302 {
303 	sockaddr_u	name;
304 
305 	if (-1 == sock4) {
306 		sock4 = socket(PF_INET, SOCK_DGRAM, 0);
307 		if (-1 == sock4) {
308 			/* error getting a socket */
309 			msyslog(LOG_ERR, "open_sockets: socket(PF_INET) failed: %m");
310 			exit(1);
311 		}
312 		/* Make it non-blocking */
313 		make_socket_nonblocking(sock4);
314 
315 		/* Let's try using a wildcard... */
316 		ZERO(name);
317 		AF(&name) = AF_INET;
318 		SET_ADDR4N(&name, INADDR_ANY);
319 		SET_PORT(&name, (HAVE_OPT(USERESERVEDPORT) ? 123 : 0));
320 
321 		if (-1 == bind(sock4, &name.sa,
322 			       SOCKLEN(&name))) {
323 			msyslog(LOG_ERR, "open_sockets: bind(sock4) failed: %m");
324 			exit(1);
325 		}
326 
327 		/* Register an NTP callback for recv/timeout */
328 		ev_sock4 = event_new(base, sock4,
329 				     EV_TIMEOUT | EV_READ | EV_PERSIST,
330 				     &sock_cb, NULL);
331 		if (NULL == ev_sock4) {
332 			msyslog(LOG_ERR,
333 				"open_sockets: event_new(base, sock4) failed!");
334 		} else {
335 			event_add(ev_sock4, &wakeup_tv);
336 		}
337 	}
338 
339 	/* We may not always have IPv6... */
340 	if (-1 == sock6 && ipv6_works) {
341 		sock6 = socket(PF_INET6, SOCK_DGRAM, 0);
342 		if (-1 == sock6 && ipv6_works) {
343 			/* error getting a socket */
344 			msyslog(LOG_ERR, "open_sockets: socket(PF_INET6) failed: %m");
345 			exit(1);
346 		}
347 		/* Make it non-blocking */
348 		make_socket_nonblocking(sock6);
349 
350 		/* Let's try using a wildcard... */
351 		ZERO(name);
352 		AF(&name) = AF_INET6;
353 		SET_ADDR6N(&name, in6addr_any);
354 		SET_PORT(&name, (HAVE_OPT(USERESERVEDPORT) ? 123 : 0));
355 
356 		if (-1 == bind(sock6, &name.sa,
357 			       SOCKLEN(&name))) {
358 			msyslog(LOG_ERR, "open_sockets: bind(sock6) failed: %m");
359 			exit(1);
360 		}
361 		/* Register an NTP callback for recv/timeout */
362 		ev_sock6 = event_new(base, sock6,
363 				     EV_TIMEOUT | EV_READ | EV_PERSIST,
364 				     &sock_cb, NULL);
365 		if (NULL == ev_sock6) {
366 			msyslog(LOG_ERR,
367 				"open_sockets: event_new(base, sock6) failed!");
368 		} else {
369 			event_add(ev_sock6, &wakeup_tv);
370 		}
371 	}
372 
373 	return;
374 }
375 
376 
377 /*
378 ** handle_lookup
379 */
380 void
381 handle_lookup(
382 	const char *name,
383 	int flags
384 	)
385 {
386 	struct addrinfo	hints;	/* Local copy is OK */
387 	struct dns_ctx *ctx;
388 	char *		name_copy;
389 	size_t		name_sz;
390 	size_t		octets;
391 
392 	TRACE(1, ("handle_lookup(%s,%#x)\n", name, flags));
393 
394 	ZERO(hints);
395 	hints.ai_family = ai_fam_pref;
396 	hints.ai_flags = AI_CANONNAME | Z_AI_NUMERICSERV;
397 	/*
398 	** Unless we specify a socktype, we'll get at least two
399 	** entries for each address: one for TCP and one for
400 	** UDP. That's not what we want.
401 	*/
402 	hints.ai_socktype = SOCK_DGRAM;
403 	hints.ai_protocol = IPPROTO_UDP;
404 
405 	name_sz = 1 + strlen(name);
406 	octets = sizeof(*ctx) + name_sz;	// Space for a ctx and the name
407 	ctx = emalloc_zero(octets);		// ctx at ctx[0]
408 	name_copy = (char *)(ctx + 1);		// Put the name at ctx[1]
409 	memcpy(name_copy, name, name_sz);	// copy the name to ctx[1]
410 	ctx->name = name_copy;			// point to it...
411 	ctx->flags = flags;
412 	ctx->timeout = response_tv;
413 	ctx->key = NULL;
414 
415 	/* The following should arguably be passed in... */
416 	if (ENABLED_OPT(AUTHENTICATION)) {
417 		ctx->key_id = OPT_VALUE_AUTHENTICATION;
418 		get_key(ctx->key_id, &ctx->key);
419 		if (NULL == ctx->key) {
420 			fprintf(stderr, "%s: Authentication with keyID %d requested, but no matching keyID found in <%s>!\n",
421 				progname, ctx->key_id, OPT_ARG(KEYFILE));
422 			exit(1);
423 		}
424 	} else {
425 		ctx->key_id = -1;
426 	}
427 
428 	++n_pending_dns;
429 	getaddrinfo_sometime(name, "123", &hints, 0,
430 			     &sntp_name_resolved, ctx);
431 }
432 
433 
434 /*
435 ** DNS Callback:
436 ** - For each IP:
437 ** - - open a socket
438 ** - - increment n_pending_ntp
439 ** - - send a request if this is a Unicast callback
440 ** - - queue wait for response
441 ** - decrement n_pending_dns
442 */
443 void
444 sntp_name_resolved(
445 	int			rescode,
446 	int			gai_errno,
447 	void *			context,
448 	const char *		name,
449 	const char *		service,
450 	const struct addrinfo *	hints,
451 	const struct addrinfo *	addr
452 	)
453 {
454 	struct dns_ctx *	dctx;
455 	sent_pkt *		spkt;
456 	const struct addrinfo *	ai;
457 	SOCKET			sock;
458 	u_int			xmt_delay_v4;
459 	u_int			xmt_delay_v6;
460 	u_int			xmt_delay;
461 	size_t			octets;
462 
463 	xmt_delay_v4 = 0;
464 	xmt_delay_v6 = 0;
465 	dctx = context;
466 	if (rescode) {
467 #ifdef EAI_SYSTEM
468 		if (EAI_SYSTEM == rescode) {
469 			errno = gai_errno;
470 			mfprintf(stderr, "%s lookup error %m\n",
471 				 dctx->name);
472 		} else
473 #endif
474 			fprintf(stderr, "%s lookup error %s\n",
475 				dctx->name, gai_strerror(rescode));
476 	} else {
477 		TRACE(3, ("%s [%s]\n", dctx->name,
478 			  (addr->ai_canonname != NULL)
479 			      ? addr->ai_canonname
480 			      : ""));
481 
482 		for (ai = addr; ai != NULL; ai = ai->ai_next) {
483 
484 			if (check_kod(ai))
485 				continue;
486 
487 			switch (ai->ai_family) {
488 
489 			case AF_INET:
490 				sock = sock4;
491 				xmt_delay = xmt_delay_v4;
492 				xmt_delay_v4++;
493 				break;
494 
495 			case AF_INET6:
496 				if (!ipv6_works)
497 					continue;
498 
499 				sock = sock6;
500 				xmt_delay = xmt_delay_v6;
501 				xmt_delay_v6++;
502 				break;
503 
504 			default:
505 				msyslog(LOG_ERR, "sntp_name_resolved: unexpected ai_family: %d",
506 					ai->ai_family);
507 				exit(1);
508 				break;
509 			}
510 
511 			/*
512 			** We're waiting for a response for either unicast
513 			** or broadcast, so...
514 			*/
515 			++n_pending_ntp;
516 
517 			/* If this is for a unicast IP, queue a request */
518 			if (dctx->flags & CTX_UCST) {
519 				spkt = emalloc_zero(sizeof(*spkt));
520 				spkt->dctx = dctx;
521 				octets = min(ai->ai_addrlen, sizeof(spkt->addr));
522 				memcpy(&spkt->addr, ai->ai_addr, octets);
523 				queue_xmt(sock, dctx, spkt, xmt_delay);
524 			}
525 		}
526 	}
527 	/* n_pending_dns really should be >0 here... */
528 	--n_pending_dns;
529 	check_exit_conditions();
530 }
531 
532 
533 /*
534 ** queue_xmt
535 */
536 void
537 queue_xmt(
538 	SOCKET			sock,
539 	struct dns_ctx *	dctx,
540 	sent_pkt *		spkt,
541 	u_int			xmt_delay
542 	)
543 {
544 	sockaddr_u *	dest;
545 	sent_pkt **	pkt_listp;
546 	sent_pkt *	match;
547 	xmt_ctx *	xctx;
548 	struct timeval	start_cb;
549 	struct timeval	delay;
550 
551 	dest = &spkt->addr;
552 	if (IS_IPV6(dest))
553 		pkt_listp = &v6_pkts_list;
554 	else
555 		pkt_listp = &v4_pkts_list;
556 
557 	/* reject attempts to add address already listed */
558 	for (match = *pkt_listp; match != NULL; match = match->link) {
559 		if (ADDR_PORT_EQ(&spkt->addr, &match->addr)) {
560 			if (strcasecmp(spkt->dctx->name,
561 				       match->dctx->name))
562 				printf("%s %s duplicate address from %s ignored.\n",
563 				       sptoa(&match->addr),
564 				       match->dctx->name,
565 				       spkt->dctx->name);
566 			else
567 				printf("%s %s, duplicate address ignored.\n",
568 				       sptoa(&match->addr),
569 				       match->dctx->name);
570 			dec_pending_ntp(spkt->dctx->name, &spkt->addr);
571 			free(spkt);
572 			return;
573 		}
574 	}
575 
576 	LINK_SLIST(*pkt_listp, spkt, link);
577 
578 	xctx = emalloc_zero(sizeof(*xctx));
579 	xctx->sock = sock;
580 	xctx->spkt = spkt;
581 	gettimeofday_cached(base, &start_cb);
582 	xctx->sched = start_cb.tv_sec + (2 * xmt_delay);
583 
584 	LINK_SORT_SLIST(xmt_q, xctx, (xctx->sched < L_S_S_CUR()->sched),
585 			link, xmt_ctx);
586 	if (xmt_q == xctx) {
587 		/*
588 		 * The new entry is the first scheduled.  The timer is
589 		 * either not active or is set for the second xmt
590 		 * context in xmt_q.
591 		 */
592 		if (NULL == ev_xmt_timer)
593 			ev_xmt_timer = event_new(base, INVALID_SOCKET,
594 						 EV_TIMEOUT,
595 						 &xmt_timer_cb, NULL);
596 		if (NULL == ev_xmt_timer) {
597 			msyslog(LOG_ERR,
598 				"queue_xmt: event_new(base, -1, EV_TIMEOUT) failed!");
599 			exit(1);
600 		}
601 		ZERO(delay);
602 		if (xctx->sched > start_cb.tv_sec)
603 			delay.tv_sec = xctx->sched - start_cb.tv_sec;
604 		event_add(ev_xmt_timer, &delay);
605 		TRACE(2, ("queue_xmt: xmt timer for %u usec\n",
606 			  (u_int)delay.tv_usec));
607 	}
608 }
609 
610 
611 /*
612 ** xmt_timer_cb
613 */
614 void
615 xmt_timer_cb(
616 	evutil_socket_t	fd,
617 	short		what,
618 	void *		ctx
619 	)
620 {
621 	struct timeval	start_cb;
622 	struct timeval	delay;
623 	xmt_ctx *	x;
624 
625 	UNUSED_ARG(fd);
626 	UNUSED_ARG(ctx);
627 	DEBUG_INSIST(EV_TIMEOUT == what);
628 
629 	if (NULL == xmt_q || shutting_down)
630 		return;
631 	gettimeofday_cached(base, &start_cb);
632 	if (xmt_q->sched <= start_cb.tv_sec) {
633 		UNLINK_HEAD_SLIST(x, xmt_q, link);
634 		TRACE(2, ("xmt_timer_cb: at .%6.6u -> %s\n",
635 			  (u_int)start_cb.tv_usec, stoa(&x->spkt->addr)));
636 		xmt(x);
637 		free(x);
638 		if (NULL == xmt_q)
639 			return;
640 	}
641 	if (xmt_q->sched <= start_cb.tv_sec) {
642 		event_add(ev_xmt_timer, &gap);
643 		TRACE(2, ("xmt_timer_cb: at .%6.6u gap %6.6u\n",
644 			  (u_int)start_cb.tv_usec,
645 			  (u_int)gap.tv_usec));
646 	} else {
647 		delay.tv_sec = xmt_q->sched - start_cb.tv_sec;
648 		delay.tv_usec = 0;
649 		event_add(ev_xmt_timer, &delay);
650 		TRACE(2, ("xmt_timer_cb: at .%6.6u next %ld seconds\n",
651 			  (u_int)start_cb.tv_usec,
652 			  (long)delay.tv_sec));
653 	}
654 }
655 
656 
657 /*
658 ** xmt()
659 */
660 void
661 xmt(
662 	xmt_ctx *	xctx
663 	)
664 {
665 	SOCKET		sock = xctx->sock;
666 	struct dns_ctx *dctx = xctx->spkt->dctx;
667 	sent_pkt *	spkt = xctx->spkt;
668 	sockaddr_u *	dst = &spkt->addr;
669 	struct timeval	tv_xmt;
670 	struct pkt	x_pkt;
671 	size_t		pkt_len;
672 	int		sent;
673 
674 	if (0 != gettimeofday(&tv_xmt, NULL)) {
675 		msyslog(LOG_ERR,
676 			"xmt: gettimeofday() failed: %m");
677 		exit(1);
678 	}
679 	tv_xmt.tv_sec += JAN_1970;
680 
681 	pkt_len = generate_pkt(&x_pkt, &tv_xmt, dctx->key_id,
682 			       dctx->key);
683 
684 	sent = sendpkt(sock, dst, &x_pkt, pkt_len);
685 	if (sent) {
686 		/* Save the packet we sent... */
687 		memcpy(&spkt->x_pkt, &x_pkt, min(sizeof(spkt->x_pkt),
688 		       pkt_len));
689 		spkt->stime = tv_xmt.tv_sec - JAN_1970;
690 
691 		TRACE(2, ("xmt: %lx.%6.6u %s %s\n", (u_long)tv_xmt.tv_sec,
692 			  (u_int)tv_xmt.tv_usec, dctx->name, stoa(dst)));
693 	} else {
694 		dec_pending_ntp(dctx->name, dst);
695 	}
696 
697 	return;
698 }
699 
700 
701 /*
702  * timeout_queries() -- give up on unrequited NTP queries
703  */
704 void
705 timeout_queries(void)
706 {
707 	struct timeval	start_cb;
708 	u_int		idx;
709 	sent_pkt *	head;
710 	sent_pkt *	spkt;
711 	sent_pkt *	spkt_next;
712 	long		age;
713 	int didsomething = 0;
714 
715 	TRACE(3, ("timeout_queries: called to check %u items\n",
716 		  (unsigned)COUNTOF(fam_listheads)));
717 
718 	gettimeofday_cached(base, &start_cb);
719 	for (idx = 0; idx < COUNTOF(fam_listheads); idx++) {
720 		head = fam_listheads[idx];
721 		for (spkt = head; spkt != NULL; spkt = spkt_next) {
722 			char xcst;
723 
724 			didsomething = 1;
725 			switch (spkt->dctx->flags & CTX_xCST) {
726 			    case CTX_BCST:
727 				xcst = 'B';
728 				break;
729 
730 			    case CTX_UCST:
731 				xcst = 'U';
732 				break;
733 
734 			    default:
735 				INSIST(!"spkt->dctx->flags neither UCST nor BCST");
736 				break;
737 			}
738 
739 			spkt_next = spkt->link;
740 			if (0 == spkt->stime || spkt->done)
741 				continue;
742 			age = start_cb.tv_sec - spkt->stime;
743 			TRACE(3, ("%s %s %cCST age %ld\n",
744 				  stoa(&spkt->addr),
745 				  spkt->dctx->name, xcst, age));
746 			if (age > response_timeout)
747 				timeout_query(spkt);
748 		}
749 	}
750 	// Do we care about didsomething?
751 	TRACE(3, ("timeout_queries: didsomething is %d, age is %ld\n",
752 		  didsomething, (long) (start_cb.tv_sec - start_tv.tv_sec)));
753 	if (start_cb.tv_sec - start_tv.tv_sec > response_timeout) {
754 		TRACE(3, ("timeout_queries: bail!\n"));
755 		event_base_loopexit(base, NULL);
756 		shutting_down = TRUE;
757 	}
758 }
759 
760 
761 void dec_pending_ntp(
762 	const char *	name,
763 	sockaddr_u *	server
764 	)
765 {
766 	if (n_pending_ntp > 0) {
767 		--n_pending_ntp;
768 		check_exit_conditions();
769 	} else {
770 		INSIST(0 == n_pending_ntp);
771 		TRACE(1, ("n_pending_ntp was zero before decrement for %s\n",
772 			  hostnameaddr(name, server)));
773 	}
774 }
775 
776 
777 void timeout_query(
778 	sent_pkt *	spkt
779 	)
780 {
781 	sockaddr_u *	server;
782 	char		xcst;
783 
784 
785 	switch (spkt->dctx->flags & CTX_xCST) {
786 	    case CTX_BCST:
787 		xcst = 'B';
788 		break;
789 
790 	    case CTX_UCST:
791 		xcst = 'U';
792 		break;
793 
794 	    default:
795 		INSIST(!"spkt->dctx->flags neither UCST nor BCST");
796 		break;
797 	}
798 	spkt->done = TRUE;
799 	server = &spkt->addr;
800 	msyslog(LOG_INFO, "%s no %cCST response after %d seconds",
801 		hostnameaddr(spkt->dctx->name, server), xcst,
802 		response_timeout);
803 	dec_pending_ntp(spkt->dctx->name, server);
804 	return;
805 }
806 
807 
808 /*
809 ** check_kod
810 */
811 int
812 check_kod(
813 	const struct addrinfo *	ai
814 	)
815 {
816 	char *hostname;
817 	struct kod_entry *reason;
818 
819 	/* Is there a KoD on file for this address? */
820 	hostname = addrinfo_to_str(ai);
821 	TRACE(2, ("check_kod: checking <%s>\n", hostname));
822 	if (search_entry(hostname, &reason)) {
823 		printf("prior KoD for %s, skipping.\n",
824 			hostname);
825 		free(reason);
826 		free(hostname);
827 
828 		return 1;
829 	}
830 	free(hostname);
831 
832 	return 0;
833 }
834 
835 
836 /*
837 ** Socket readable/timeout Callback:
838 ** Read in the packet
839 ** Unicast:
840 ** - close socket
841 ** - decrement n_pending_ntp
842 ** - If packet is good, set the time and "exit"
843 ** Broadcast:
844 ** - If packet is good, set the time and "exit"
845 */
846 void
847 sock_cb(
848 	evutil_socket_t fd,
849 	short what,
850 	void *ptr
851 	)
852 {
853 	sockaddr_u	sender;
854 	sockaddr_u *	psau;
855 	sent_pkt **	p_pktlist;
856 	sent_pkt *	spkt;
857 	int		rpktl;
858 	int		rc;
859 
860 	INSIST(sock4 == fd || sock6 == fd);
861 
862 	TRACE(3, ("sock_cb: event on sock%s:%s%s%s%s\n",
863 		  (fd == sock6)
864 		      ? "6"
865 		      : "4",
866 		  (what & EV_TIMEOUT) ? " timeout" : "",
867 		  (what & EV_READ)    ? " read" : "",
868 		  (what & EV_WRITE)   ? " write" : "",
869 		  (what & EV_SIGNAL)  ? " signal" : ""));
870 
871 	if (!(EV_READ & what)) {
872 		if (EV_TIMEOUT & what)
873 			timeout_queries();
874 
875 		return;
876 	}
877 
878 	/* Read in the packet */
879 	rpktl = recvdata(fd, &sender, &rbuf, sizeof(rbuf));
880 	if (rpktl < 0) {
881 		msyslog(LOG_DEBUG, "recvfrom error %m");
882 		return;
883 	}
884 
885 	if (sock6 == fd)
886 		p_pktlist = &v6_pkts_list;
887 	else
888 		p_pktlist = &v4_pkts_list;
889 
890 	for (spkt = *p_pktlist; spkt != NULL; spkt = spkt->link) {
891 		psau = &spkt->addr;
892 		if (SOCK_EQ(&sender, psau))
893 			break;
894 	}
895 	if (NULL == spkt) {
896 		msyslog(LOG_WARNING,
897 			"Packet from unexpected source %s dropped",
898 			sptoa(&sender));
899 		return;
900 	}
901 
902 	TRACE(1, ("sock_cb: %s %s\n", spkt->dctx->name,
903 		  sptoa(&sender)));
904 
905 	rpktl = process_pkt(&r_pkt, &sender, rpktl, MODE_SERVER,
906 			    &spkt->x_pkt, "sock_cb");
907 
908 	TRACE(2, ("sock_cb: process_pkt returned %d\n", rpktl));
909 
910 	/* If this is a Unicast packet, one down ... */
911 	if (!spkt->done && (CTX_UCST & spkt->dctx->flags)) {
912 		dec_pending_ntp(spkt->dctx->name, &spkt->addr);
913 		spkt->done = TRUE;
914 	}
915 
916 
917 	/* If the packet is good, set the time and we're all done */
918 	rc = handle_pkt(rpktl, &r_pkt, &spkt->addr, spkt->dctx->name);
919 	if (0 != rc)
920 		TRACE(1, ("sock_cb: handle_pkt() returned %d\n", rc));
921 	check_exit_conditions();
922 }
923 
924 
925 /*
926  * check_exit_conditions()
927  *
928  * If sntp has a reply, ask the event loop to stop after this round of
929  * callbacks, unless --wait was used.
930  */
931 void
932 check_exit_conditions(void)
933 {
934 	if ((0 == n_pending_ntp && 0 == n_pending_dns) ||
935 	    (time_derived && !HAVE_OPT(WAIT))) {
936 		event_base_loopexit(base, NULL);
937 		shutting_down = TRUE;
938 	} else {
939 		TRACE(2, ("%d NTP and %d name queries pending\n",
940 			  n_pending_ntp, n_pending_dns));
941 	}
942 }
943 
944 
945 /*
946  * sntp_addremove_fd() is invoked by the intres blocking worker code
947  * to read from a pipe, or to stop same.
948  */
949 void sntp_addremove_fd(
950 	int	fd,
951 	int	is_pipe,
952 	int	remove_it
953 	)
954 {
955 	u_int		idx;
956 	blocking_child *c;
957 	struct event *	ev;
958 
959 #ifdef HAVE_SOCKETPAIR
960 	if (is_pipe) {
961 		/* sntp only asks for EV_FEATURE_FDS without HAVE_SOCKETPAIR */
962 		msyslog(LOG_ERR, "fatal: pipes not supported on systems with socketpair()");
963 		exit(1);
964 	}
965 #endif
966 
967 	c = NULL;
968 	for (idx = 0; idx < blocking_children_alloc; idx++) {
969 		c = blocking_children[idx];
970 		if (NULL == c)
971 			continue;
972 		if (fd == c->resp_read_pipe)
973 			break;
974 	}
975 	if (idx == blocking_children_alloc)
976 		return;
977 
978 	if (remove_it) {
979 		ev = c->resp_read_ctx;
980 		c->resp_read_ctx = NULL;
981 		event_del(ev);
982 		event_free(ev);
983 
984 		return;
985 	}
986 
987 	ev = event_new(base, fd, EV_READ | EV_PERSIST,
988 		       &worker_resp_cb, c);
989 	if (NULL == ev) {
990 		msyslog(LOG_ERR,
991 			"sntp_addremove_fd: event_new(base, fd) failed!");
992 		return;
993 	}
994 	c->resp_read_ctx = ev;
995 	event_add(ev, NULL);
996 }
997 
998 
999 /* called by forked intres child to close open descriptors */
1000 #ifdef WORK_FORK
1001 void
1002 kill_asyncio(
1003 	int	startfd
1004 	)
1005 {
1006 	if (INVALID_SOCKET != sock4) {
1007 		closesocket(sock4);
1008 		sock4 = INVALID_SOCKET;
1009 	}
1010 	if (INVALID_SOCKET != sock6) {
1011 		closesocket(sock6);
1012 		sock6 = INVALID_SOCKET;
1013 	}
1014 	if (INVALID_SOCKET != bsock4) {
1015 		closesocket(bsock4);
1016 		bsock4 = INVALID_SOCKET;
1017 	}
1018 	if (INVALID_SOCKET != bsock6) {
1019 		closesocket(bsock6);
1020 		bsock6 = INVALID_SOCKET;
1021 	}
1022 }
1023 #endif
1024 
1025 
1026 /*
1027  * worker_resp_cb() is invoked when resp_read_pipe is readable.
1028  */
1029 void
1030 worker_resp_cb(
1031 	evutil_socket_t	fd,
1032 	short		what,
1033 	void *		ctx	/* blocking_child * */
1034 	)
1035 {
1036 	blocking_child *	c;
1037 
1038 	REQUIRE(EV_READ & what);
1039 	c = ctx;
1040 	INSIST(fd == c->resp_read_pipe);
1041 	process_blocking_resp(c);
1042 }
1043 
1044 
1045 /*
1046  * intres_timeout_req(s) is invoked in the parent to schedule an idle
1047  * timeout to fire in s seconds, if not reset earlier by a call to
1048  * intres_timeout_req(0), which clears any pending timeout.  When the
1049  * timeout expires, worker_idle_timer_fired() is invoked (again, in the
1050  * parent).
1051  *
1052  * sntp and ntpd each provide implementations adapted to their timers.
1053  */
1054 void
1055 intres_timeout_req(
1056 	u_int	seconds		/* 0 cancels */
1057 	)
1058 {
1059 	struct timeval	tv_to;
1060 
1061 	if (NULL == ev_worker_timeout) {
1062 		ev_worker_timeout = event_new(base, -1,
1063 					      EV_TIMEOUT | EV_PERSIST,
1064 					      &worker_timeout, NULL);
1065 		INSIST(NULL != ev_worker_timeout);
1066 	} else {
1067 		event_del(ev_worker_timeout);
1068 	}
1069 	if (0 == seconds)
1070 		return;
1071 	tv_to.tv_sec = seconds;
1072 	tv_to.tv_usec = 0;
1073 	event_add(ev_worker_timeout, &tv_to);
1074 }
1075 
1076 
1077 void
1078 worker_timeout(
1079 	evutil_socket_t	fd,
1080 	short		what,
1081 	void *		ctx
1082 	)
1083 {
1084 	UNUSED_ARG(fd);
1085 	UNUSED_ARG(ctx);
1086 
1087 	REQUIRE(EV_TIMEOUT & what);
1088 	worker_idle_timer_fired();
1089 }
1090 
1091 
1092 void
1093 sntp_libevent_log_cb(
1094 	int		severity,
1095 	const char *	msg
1096 	)
1097 {
1098 	int		level;
1099 
1100 	switch (severity) {
1101 
1102 	default:
1103 	case _EVENT_LOG_DEBUG:
1104 		level = LOG_DEBUG;
1105 		break;
1106 
1107 	case _EVENT_LOG_MSG:
1108 		level = LOG_NOTICE;
1109 		break;
1110 
1111 	case _EVENT_LOG_WARN:
1112 		level = LOG_WARNING;
1113 		break;
1114 
1115 	case _EVENT_LOG_ERR:
1116 		level = LOG_ERR;
1117 		break;
1118 	}
1119 
1120 	msyslog(level, "%s", msg);
1121 }
1122 
1123 
1124 int
1125 generate_pkt (
1126 	struct pkt *x_pkt,
1127 	const struct timeval *tv_xmt,
1128 	int key_id,
1129 	struct key *pkt_key
1130 	)
1131 {
1132 	l_fp	xmt_fp;
1133 	int	pkt_len;
1134 	int	mac_size;
1135 
1136 	pkt_len = LEN_PKT_NOMAC;
1137 	ZERO(*x_pkt);
1138 	TVTOTS(tv_xmt, &xmt_fp);
1139 	HTONL_FP(&xmt_fp, &x_pkt->xmt);
1140 	x_pkt->stratum = STRATUM_TO_PKT(STRATUM_UNSPEC);
1141 	x_pkt->ppoll = 8;
1142 	/* FIXME! Modus broadcast + adr. check -> bdr. pkt */
1143 	set_li_vn_mode(x_pkt, LEAP_NOTINSYNC, ntpver, 3);
1144 	if (debug > 0) {
1145 		printf("generate_pkt: key_id %d, key pointer %p\n", key_id, pkt_key);
1146 	}
1147 	if (pkt_key != NULL) {
1148 		x_pkt->exten[0] = htonl(key_id);
1149 		mac_size = make_mac(x_pkt, pkt_len, pkt_key,
1150 				    (char *)&x_pkt->exten[1], MAX_MDG_LEN);
1151 		if (mac_size > 0)
1152 			pkt_len += mac_size + KEY_MAC_LEN;
1153 #ifdef DEBUG
1154 		if (debug > 0) {
1155 			printf("generate_pkt: mac_size is %d\n", mac_size);
1156 		}
1157 #endif
1158 
1159 	}
1160 	return pkt_len;
1161 }
1162 
1163 
1164 int
1165 handle_pkt(
1166 	int		rpktl,
1167 	struct pkt *	rpkt,
1168 	sockaddr_u *	host,
1169 	const char *	hostname
1170 	)
1171 {
1172 	char		disptxt[32];
1173 	const char *	addrtxt;
1174 	struct timeval	tv_dst;
1175 	int		cnt;
1176 	int		sw_case;
1177 	int		digits;
1178 	int		stratum;
1179 	char *		ref;
1180 	char *		ts_str;
1181 	const char *	leaptxt;
1182 	double		offset;
1183 	double		precision;
1184 	double		synch_distance;
1185 	char *		p_SNTP_PRETEND_TIME;
1186 	time_t		pretend_time;
1187 #if SIZEOF_TIME_T == 8
1188 	long long	ll;
1189 #else
1190 	long		l;
1191 #endif
1192 
1193 	ts_str = NULL;
1194 
1195 	if (rpktl > 0)
1196 		sw_case = 1;
1197 	else
1198 		sw_case = rpktl;
1199 
1200 	switch (sw_case) {
1201 
1202 	case SERVER_UNUSEABLE:
1203 		return -1;
1204 		break;
1205 
1206 	case PACKET_UNUSEABLE:
1207 		break;
1208 
1209 	case SERVER_AUTH_FAIL:
1210 		break;
1211 
1212 	case KOD_DEMOBILIZE:
1213 		/* Received a DENY or RESTR KOD packet */
1214 		addrtxt = stoa(host);
1215 		ref = (char *)&rpkt->refid;
1216 		add_entry(addrtxt, ref);
1217 		msyslog(LOG_WARNING, "KOD code %c%c%c%c from %s %s",
1218 			ref[0], ref[1], ref[2], ref[3], addrtxt, hostname);
1219 		break;
1220 
1221 	case KOD_RATE:
1222 		/*
1223 		** Hmm...
1224 		** We should probably call add_entry() with an
1225 		** expiration timestamp of several seconds in the future,
1226 		** and back-off even more if we get more RATE responses.
1227 		*/
1228 		break;
1229 
1230 	case 1:
1231 		TRACE(3, ("handle_pkt: %d bytes from %s %s\n",
1232 			  rpktl, stoa(host), hostname));
1233 
1234 		gettimeofday_cached(base, &tv_dst);
1235 
1236 		p_SNTP_PRETEND_TIME = getenv("SNTP_PRETEND_TIME");
1237 		if (p_SNTP_PRETEND_TIME) {
1238 			pretend_time = 0;
1239 #if SIZEOF_TIME_T == 4
1240 			if (1 == sscanf(p_SNTP_PRETEND_TIME, "%ld", &l))
1241 				pretend_time = (time_t)l;
1242 #elif SIZEOF_TIME_T == 8
1243 			if (1 == sscanf(p_SNTP_PRETEND_TIME, "%lld", &ll))
1244 				pretend_time = (time_t)ll;
1245 #else
1246 # include "GRONK: unexpected value for SIZEOF_TIME_T"
1247 #endif
1248 			if (0 != pretend_time)
1249 				tv_dst.tv_sec = pretend_time;
1250 		}
1251 
1252 		offset_calculation(rpkt, rpktl, &tv_dst, &offset,
1253 				   &precision, &synch_distance);
1254 		time_derived = TRUE;
1255 
1256 		for (digits = 0; (precision *= 10.) < 1.; ++digits)
1257 			/* empty */ ;
1258 		if (digits > 6)
1259 			digits = 6;
1260 
1261 		ts_str = tv_to_str(&tv_dst);
1262 		stratum = rpkt->stratum;
1263 		if (0 == stratum)
1264 				stratum = 16;
1265 
1266 		if (synch_distance > 0.) {
1267 			cnt = snprintf(disptxt, sizeof(disptxt),
1268 				       " +/- %f", synch_distance);
1269 			if ((size_t)cnt >= sizeof(disptxt))
1270 				snprintf(disptxt, sizeof(disptxt),
1271 					 "ERROR %d >= %d", cnt,
1272 					 (int)sizeof(disptxt));
1273 		} else {
1274 			disptxt[0] = '\0';
1275 		}
1276 
1277 		switch (PKT_LEAP(rpkt->li_vn_mode)) {
1278 		    case LEAP_NOWARNING:
1279 		    	leaptxt = "no-leap";
1280 			break;
1281 		    case LEAP_ADDSECOND:
1282 		    	leaptxt = "add-leap";
1283 			break;
1284 		    case LEAP_DELSECOND:
1285 		    	leaptxt = "del-leap";
1286 			break;
1287 		    case LEAP_NOTINSYNC:
1288 		    	leaptxt = "unsync";
1289 			break;
1290 		    default:
1291 		    	leaptxt = "LEAP-ERROR";
1292 			break;
1293 		}
1294 
1295 		msyslog(LOG_INFO, "%s %+.*f%s %s s%d %s%s", ts_str,
1296 			digits, offset, disptxt,
1297 			hostnameaddr(hostname, host), stratum,
1298 			leaptxt,
1299 			(time_adjusted)
1300 			    ? " [excess]"
1301 			    : "");
1302 		free(ts_str);
1303 
1304 		if (p_SNTP_PRETEND_TIME)
1305 			return 0;
1306 
1307 		if (!time_adjusted &&
1308 		    (ENABLED_OPT(STEP) || ENABLED_OPT(SLEW)))
1309 			return set_time(offset);
1310 
1311 		return EX_OK;
1312 	}
1313 
1314 	return 1;
1315 }
1316 
1317 
1318 void
1319 offset_calculation(
1320 	struct pkt *rpkt,
1321 	int rpktl,
1322 	struct timeval *tv_dst,
1323 	double *offset,
1324 	double *precision,
1325 	double *synch_distance
1326 	)
1327 {
1328 	l_fp p_rec, p_xmt, p_ref, p_org, tmp, dst;
1329 	u_fp p_rdly, p_rdsp;
1330 	double t21, t34, delta;
1331 
1332 	/* Convert timestamps from network to host byte order */
1333 	p_rdly = NTOHS_FP(rpkt->rootdelay);
1334 	p_rdsp = NTOHS_FP(rpkt->rootdisp);
1335 	NTOHL_FP(&rpkt->reftime, &p_ref);
1336 	NTOHL_FP(&rpkt->org, &p_org);
1337 	NTOHL_FP(&rpkt->rec, &p_rec);
1338 	NTOHL_FP(&rpkt->xmt, &p_xmt);
1339 
1340 	*precision = LOGTOD(rpkt->precision);
1341 
1342 	TRACE(3, ("offset_calculation: LOGTOD(rpkt->precision): %f\n", *precision));
1343 
1344 	/* Compute offset etc. */
1345 	tmp = p_rec;
1346 	L_SUB(&tmp, &p_org);
1347 	LFPTOD(&tmp, t21);
1348 	TVTOTS(tv_dst, &dst);
1349 	dst.l_ui += JAN_1970;
1350 	tmp = p_xmt;
1351 	L_SUB(&tmp, &dst);
1352 	LFPTOD(&tmp, t34);
1353 	*offset = (t21 + t34) / 2.;
1354 	delta = t21 - t34;
1355 
1356 	// synch_distance is:
1357 	// (peer->delay + peer->rootdelay) / 2 + peer->disp
1358 	// + peer->rootdisp + clock_phi * (current_time - peer->update)
1359 	// + peer->jitter;
1360 	//
1361 	// and peer->delay = fabs(peer->offset - p_offset) * 2;
1362 	// and peer->offset needs history, so we're left with
1363 	// p_offset = (t21 + t34) / 2.;
1364 	// peer->disp = 0; (we have no history to augment this)
1365 	// clock_phi = 15e-6;
1366 	// peer->jitter = LOGTOD(sys_precision); (we have no history to augment this)
1367 	// and ntp_proto.c:set_sys_tick_precision() should get us sys_precision.
1368 	//
1369 	// so our answer seems to be:
1370 	//
1371 	// (fabs(t21 + t34) + peer->rootdelay) / 3.
1372 	// + 0 (peer->disp)
1373 	// + peer->rootdisp
1374 	// + 15e-6 (clock_phi)
1375 	// + LOGTOD(sys_precision)
1376 
1377 	INSIST( FPTOD(p_rdly) >= 0. );
1378 #if 1
1379 	*synch_distance = (fabs(t21 + t34) + FPTOD(p_rdly)) / 3.
1380 		+ 0.
1381 		+ FPTOD(p_rdsp)
1382 		+ 15e-6
1383 		+ 0.	/* LOGTOD(sys_precision) when we can get it */
1384 		;
1385 	INSIST( *synch_distance >= 0. );
1386 #else
1387 	*synch_distance = (FPTOD(p_rdly) + FPTOD(p_rdsp))/2.0;
1388 #endif
1389 
1390 #ifdef DEBUG
1391 	if (debug > 3) {
1392 		printf("sntp rootdelay: %f\n", FPTOD(p_rdly));
1393 		printf("sntp rootdisp: %f\n", FPTOD(p_rdsp));
1394 		printf("sntp syncdist: %f\n", *synch_distance);
1395 
1396 		pkt_output(rpkt, rpktl, stdout);
1397 
1398 		printf("sntp offset_calculation: rpkt->reftime:\n");
1399 		l_fp_output(&p_ref, stdout);
1400 		printf("sntp offset_calculation: rpkt->org:\n");
1401 		l_fp_output(&p_org, stdout);
1402 		printf("sntp offset_calculation: rpkt->rec:\n");
1403 		l_fp_output(&p_rec, stdout);
1404 		printf("sntp offset_calculation: rpkt->xmt:\n");
1405 		l_fp_output(&p_xmt, stdout);
1406 	}
1407 #endif
1408 
1409 	TRACE(3, ("sntp offset_calculation:\trec - org t21: %.6f\n"
1410 		  "\txmt - dst t34: %.6f\tdelta: %.6f\toffset: %.6f\n",
1411 		  t21, t34, delta, *offset));
1412 
1413 	return;
1414 }
1415 
1416 
1417 
1418 /* Compute the 8 bits for li_vn_mode */
1419 void
1420 set_li_vn_mode (
1421 	struct pkt *spkt,
1422 	char leap,
1423 	char version,
1424 	char mode
1425 	)
1426 {
1427 	if (leap > 3) {
1428 		msyslog(LOG_DEBUG, "set_li_vn_mode: leap > 3, using max. 3");
1429 		leap = 3;
1430 	}
1431 
1432 	if ((unsigned char)version > 7) {
1433 		msyslog(LOG_DEBUG, "set_li_vn_mode: version < 0 or > 7, using 4");
1434 		version = 4;
1435 	}
1436 
1437 	if (mode > 7) {
1438 		msyslog(LOG_DEBUG, "set_li_vn_mode: mode > 7, using client mode 3");
1439 		mode = 3;
1440 	}
1441 
1442 	spkt->li_vn_mode  = leap << 6;
1443 	spkt->li_vn_mode |= version << 3;
1444 	spkt->li_vn_mode |= mode;
1445 }
1446 
1447 
1448 /*
1449 ** set_time applies 'offset' to the local clock.
1450 */
1451 int
1452 set_time(
1453 	double offset
1454 	)
1455 {
1456 	int rc;
1457 
1458 	if (time_adjusted)
1459 		return EX_OK;
1460 
1461 	/*
1462 	** If we can step but we cannot slew, then step.
1463 	** If we can step or slew and and |offset| > steplimit, then step.
1464 	*/
1465 	if (ENABLED_OPT(STEP) &&
1466 	    (   !ENABLED_OPT(SLEW)
1467 	     || (ENABLED_OPT(SLEW) && (fabs(offset) > steplimit))
1468 	    )) {
1469 		rc = step_systime(offset);
1470 
1471 		/* If there was a problem, can we rely on errno? */
1472 		if (1 == rc)
1473 			time_adjusted = TRUE;
1474 		return (time_adjusted)
1475 			   ? EX_OK
1476 			   : 1;
1477 		/*
1478 		** In case of error, what should we use?
1479 		** EX_UNAVAILABLE?
1480 		** EX_OSERR?
1481 		** EX_NOPERM?
1482 		*/
1483 	}
1484 
1485 	if (ENABLED_OPT(SLEW)) {
1486 		rc = adj_systime(offset);
1487 
1488 		/* If there was a problem, can we rely on errno? */
1489 		if (1 == rc)
1490 			time_adjusted = TRUE;
1491 		return (time_adjusted)
1492 			   ? EX_OK
1493 			   : 1;
1494 		/*
1495 		** In case of error, what should we use?
1496 		** EX_UNAVAILABLE?
1497 		** EX_OSERR?
1498 		** EX_NOPERM?
1499 		*/
1500 	}
1501 
1502 	return EX_SOFTWARE;
1503 }
1504 
1505 
1506 int
1507 libevent_version_ok(void)
1508 {
1509 	ev_uint32_t v_compile_maj;
1510 	ev_uint32_t v_run_maj;
1511 
1512 	v_compile_maj = LIBEVENT_VERSION_NUMBER & 0xffff0000;
1513 	v_run_maj = event_get_version_number() & 0xffff0000;
1514 	if (v_compile_maj != v_run_maj) {
1515 		fprintf(stderr,
1516 			"Incompatible libevent versions: have %s, built with %s\n",
1517 			event_get_version(),
1518 			LIBEVENT_VERSION);
1519 		return 0;
1520 	}
1521 	return 1;
1522 }
1523 
1524 /*
1525  * gettimeofday_cached()
1526  *
1527  * Clones the event_base_gettimeofday_cached() interface but ensures the
1528  * times are always on the gettimeofday() 1970 scale.  Older libevent 2
1529  * sometimes used gettimeofday(), sometimes the since-system-start
1530  * clock_gettime(CLOCK_MONOTONIC), depending on the platform.
1531  *
1532  * It is not cleanly possible to tell which timescale older libevent is
1533  * using.
1534  *
1535  * The strategy involves 1 hour thresholds chosen to be far longer than
1536  * the duration of a round of libevent callbacks, which share a cached
1537  * start-of-round time.  First compare the last cached time with the
1538  * current gettimeofday() time.  If they are within one hour, libevent
1539  * is using the proper timescale so leave the offset 0.  Otherwise,
1540  * compare libevent's cached time and the current time on the monotonic
1541  * scale.  If they are within an hour, libevent is using the monotonic
1542  * scale so calculate the offset to add to such times to bring them to
1543  * gettimeofday()'s scale.
1544  */
1545 int
1546 gettimeofday_cached(
1547 	struct event_base *	b,
1548 	struct timeval *	caller_tv
1549 	)
1550 {
1551 #if defined(_EVENT_HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
1552 	static struct event_base *	cached_b;
1553 	static struct timeval		cached;
1554 	static struct timeval		adj_cached;
1555 	static struct timeval		offset;
1556 	static int			offset_ready;
1557 	struct timeval			latest;
1558 	struct timeval			systemt;
1559 	struct timespec			ts;
1560 	struct timeval			mono;
1561 	struct timeval			diff;
1562 	int				cgt_rc;
1563 	int				gtod_rc;
1564 
1565 	event_base_gettimeofday_cached(b, &latest);
1566 	if (b == cached_b &&
1567 	    !memcmp(&latest, &cached, sizeof(latest))) {
1568 		*caller_tv = adj_cached;
1569 		return 0;
1570 	}
1571 	cached = latest;
1572 	cached_b = b;
1573 	if (!offset_ready) {
1574 		cgt_rc = clock_gettime(CLOCK_MONOTONIC, &ts);
1575 		gtod_rc = gettimeofday(&systemt, NULL);
1576 		if (0 != gtod_rc) {
1577 			msyslog(LOG_ERR,
1578 				"%s: gettimeofday() error %m",
1579 				progname);
1580 			exit(1);
1581 		}
1582 		diff = sub_tval(systemt, latest);
1583 		if (debug > 1)
1584 			printf("system minus cached %+ld.%06ld\n",
1585 			       (long)diff.tv_sec, (long)diff.tv_usec);
1586 		if (0 != cgt_rc || labs((long)diff.tv_sec) < 3600) {
1587 			/*
1588 			 * Either use_monotonic == 0, or this libevent
1589 			 * has been repaired.  Leave offset at zero.
1590 			 */
1591 		} else {
1592 			mono.tv_sec = ts.tv_sec;
1593 			mono.tv_usec = ts.tv_nsec / 1000;
1594 			diff = sub_tval(latest, mono);
1595 			if (debug > 1)
1596 				printf("cached minus monotonic %+ld.%06ld\n",
1597 				       (long)diff.tv_sec, (long)diff.tv_usec);
1598 			if (labs((long)diff.tv_sec) < 3600) {
1599 				/* older libevent2 using monotonic */
1600 				offset = sub_tval(systemt, mono);
1601 				TRACE(1, ("%s: Offsetting libevent CLOCK_MONOTONIC times  by %+ld.%06ld\n",
1602 					 "gettimeofday_cached",
1603 					 (long)offset.tv_sec,
1604 					 (long)offset.tv_usec));
1605 			}
1606 		}
1607 		offset_ready = TRUE;
1608 	}
1609 	adj_cached = add_tval(cached, offset);
1610 	*caller_tv = adj_cached;
1611 
1612 	return 0;
1613 #else
1614 	return event_base_gettimeofday_cached(b, caller_tv);
1615 #endif
1616 }
1617 
1618 /* Dummy function to satisfy libntp/work_fork.c */
1619 extern int set_user_group_ids(void);
1620 int set_user_group_ids(void)
1621 {
1622     return 1;
1623 }
1624