xref: /freebsd/contrib/ntp/sntp/main.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 #include <config.h>
2 
3 #include <event2/util.h>
4 #include <event2/event.h>
5 
6 #include "ntp_workimpl.h"
7 #ifdef WORK_THREAD
8 # include <event2/thread.h>
9 #endif
10 
11 #ifdef HAVE_SYSEXITS_H
12 # include <sysexits.h>
13 #endif
14 
15 #include "main.h"
16 #include "ntp_libopts.h"
17 #include "kod_management.h"
18 #include "networking.h"
19 #include "utilities.h"
20 #include "log.h"
21 #include "libntp.h"
22 
23 extern const char *progname;
24 
25 int shutting_down;
26 int time_derived;
27 int time_adjusted;
28 int n_pending_dns = 0;
29 int n_pending_ntp = 0;
30 int ai_fam_pref = AF_UNSPEC;
31 int ntpver = 4;
32 double steplimit = -1;
33 SOCKET sock4 = -1;		/* Socket for IPv4 */
34 SOCKET sock6 = -1;		/* Socket for IPv6 */
35 /*
36 ** BCAST *must* listen on port 123 (by default), so we can only
37 ** use the UCST sockets (above) if they too are using port 123
38 */
39 SOCKET bsock4 = -1;		/* Broadcast Socket for IPv4 */
40 SOCKET bsock6 = -1;		/* Broadcast Socket for IPv6 */
41 struct event_base *base;
42 struct event *ev_sock4;
43 struct event *ev_sock6;
44 struct event *ev_worker_timeout;
45 struct event *ev_xmt_timer;
46 
47 struct dns_ctx {
48 	const char *	name;
49 	int		flags;
50 #define CTX_BCST	0x0001
51 #define CTX_UCST	0x0002
52 #define CTX_xCST	0x0003
53 #define CTX_CONC	0x0004
54 #define CTX_unused	0xfffd
55 	int		key_id;
56 	struct timeval	timeout;
57 	struct key *	key;
58 };
59 
60 typedef struct sent_pkt_tag sent_pkt;
61 struct sent_pkt_tag {
62 	sent_pkt *		link;
63 	struct dns_ctx *	dctx;
64 	sockaddr_u		addr;
65 	time_t			stime;
66 	int			done;
67 	struct pkt		x_pkt;
68 };
69 
70 typedef struct xmt_ctx_tag xmt_ctx;
71 struct xmt_ctx_tag {
72 	xmt_ctx *		link;
73 	SOCKET			sock;
74 	time_t			sched;
75 	sent_pkt *		spkt;
76 };
77 
78 struct timeval	gap;
79 xmt_ctx *	xmt_q;
80 struct key *	keys = NULL;
81 int		response_timeout;
82 struct timeval	response_tv;
83 struct timeval	start_tv;
84 /* check the timeout at least once per second */
85 struct timeval	wakeup_tv = { 0, 888888 };
86 
87 sent_pkt *	fam_listheads[2];
88 #define v4_pkts_list	(fam_listheads[0])
89 #define v6_pkts_list	(fam_listheads[1])
90 
91 static union {
92 	struct pkt pkt;
93 	char   buf[LEN_PKT_NOMAC + NTP_MAXEXTEN + MAX_MAC_LEN];
94 } rbuf;
95 
96 #define r_pkt  rbuf.pkt
97 
98 #ifdef HAVE_DROPROOT
99 int droproot;			/* intres imports these */
100 int root_dropped;
101 #endif
102 u_long current_time;		/* libntp/authkeys.c */
103 
104 void open_sockets(void);
105 void handle_lookup(const char *name, int flags);
106 void sntp_addremove_fd(int fd, int is_pipe, int remove_it);
107 void worker_timeout(evutil_socket_t, short, void *);
108 void worker_resp_cb(evutil_socket_t, short, void *);
109 void sntp_name_resolved(int, int, void *, const char *, const char *,
110 			const struct addrinfo *,
111 			const struct addrinfo *);
112 void queue_xmt(SOCKET sock, struct dns_ctx *dctx, sent_pkt *spkt,
113 	       u_int xmt_delay);
114 void xmt_timer_cb(evutil_socket_t, short, void *ptr);
115 void xmt(xmt_ctx *xctx);
116 int  check_kod(const struct addrinfo *ai);
117 void timeout_query(sent_pkt *);
118 void timeout_queries(void);
119 void sock_cb(evutil_socket_t, short, void *);
120 void check_exit_conditions(void);
121 void sntp_libevent_log_cb(int, const char *);
122 void set_li_vn_mode(struct pkt *spkt, char leap, char version, char mode);
123 int  set_time(double offset);
124 void dec_pending_ntp(const char *, sockaddr_u *);
125 int  libevent_version_ok(void);
126 int  gettimeofday_cached(struct event_base *b, struct timeval *tv);
127 
128 
129 /*
130  * The actual main function.
131  */
132 int
133 sntp_main (
134 	int argc,
135 	char **argv,
136 	const char *sntpVersion
137 	)
138 {
139 	int			i;
140 	int			exitcode;
141 	int			optct;
142 	struct event_config *	evcfg;
143 
144 	/* Initialize logging system - sets up progname */
145 	sntp_init_logging(argv[0]);
146 
147 	if (!libevent_version_ok())
148 		exit(EX_SOFTWARE);
149 
150 	init_lib();
151 	init_auth();
152 
153 	optct = ntpOptionProcess(&sntpOptions, argc, argv);
154 	argc -= optct;
155 	argv += optct;
156 
157 
158 	debug = OPT_VALUE_SET_DEBUG_LEVEL;
159 
160 	TRACE(2, ("init_lib() done, %s%s\n",
161 		  (ipv4_works)
162 		      ? "ipv4_works "
163 		      : "",
164 		  (ipv6_works)
165 		      ? "ipv6_works "
166 		      : ""));
167 	ntpver = OPT_VALUE_NTPVERSION;
168 	steplimit = OPT_VALUE_STEPLIMIT / 1e3;
169 	gap.tv_usec = max(0, OPT_VALUE_GAP * 1000);
170 	gap.tv_usec = min(gap.tv_usec, 999999);
171 
172 	if (HAVE_OPT(LOGFILE))
173 		open_logfile(OPT_ARG(LOGFILE));
174 
175 	msyslog(LOG_INFO, "%s", sntpVersion);
176 
177 	if (0 == argc && !HAVE_OPT(BROADCAST) && !HAVE_OPT(CONCURRENT)) {
178 		printf("%s: Must supply at least one of -b hostname, -c hostname, or hostname.\n",
179 		       progname);
180 		exit(EX_USAGE);
181 	}
182 
183 
184 	/*
185 	** Eventually, we probably want:
186 	** - separate bcst and ucst timeouts (why?)
187 	** - multiple --timeout values in the commandline
188 	*/
189 
190 	response_timeout = OPT_VALUE_TIMEOUT;
191 	response_tv.tv_sec = response_timeout;
192 	response_tv.tv_usec = 0;
193 
194 	/* IPv6 available? */
195 	if (isc_net_probeipv6() != ISC_R_SUCCESS) {
196 		ai_fam_pref = AF_INET;
197 		TRACE(1, ("No ipv6 support available, forcing ipv4\n"));
198 	} else {
199 		/* Check for options -4 and -6 */
200 		if (HAVE_OPT(IPV4))
201 			ai_fam_pref = AF_INET;
202 		else if (HAVE_OPT(IPV6))
203 			ai_fam_pref = AF_INET6;
204 	}
205 
206 	/* TODO: Parse config file if declared */
207 
208 	/*
209 	** Init the KOD system.
210 	** For embedded systems with no writable filesystem,
211 	** -K /dev/null can be used to disable KoD storage.
212 	*/
213 	kod_init_kod_db(OPT_ARG(KOD), FALSE);
214 
215 	/* HMS: Check and see what happens if KEYFILE doesn't exist */
216 	auth_init(OPT_ARG(KEYFILE), &keys);
217 
218 	/*
219 	** Considering employing a variable that prevents functions of doing
220 	** anything until everything is initialized properly
221 	**
222 	** HMS: What exactly does the above mean?
223 	*/
224 	event_set_log_callback(&sntp_libevent_log_cb);
225 	if (debug > 0)
226 		event_enable_debug_mode();
227 #ifdef WORK_THREAD
228 	evthread_use_pthreads();
229 	/* we use libevent from main thread only, locks should be academic */
230 	if (debug > 0)
231 		evthread_enable_lock_debuging();
232 #endif
233 	evcfg = event_config_new();
234 	if (NULL == evcfg) {
235 		printf("%s: event_config_new() failed!\n", progname);
236 		return -1;
237 	}
238 #ifndef HAVE_SOCKETPAIR
239 	event_config_require_features(evcfg, EV_FEATURE_FDS);
240 #endif
241 	/* all libevent calls are from main thread */
242 	/* event_config_set_flag(evcfg, EVENT_BASE_FLAG_NOLOCK); */
243 	base = event_base_new_with_config(evcfg);
244 	event_config_free(evcfg);
245 	if (NULL == base) {
246 		printf("%s: event_base_new() failed!\n", progname);
247 		return -1;
248 	}
249 
250 	/* wire into intres resolver */
251 	worker_per_query = TRUE;
252 	addremove_io_fd = &sntp_addremove_fd;
253 
254 	open_sockets();
255 
256 	if (HAVE_OPT(BROADCAST)) {
257 		int		cn = STACKCT_OPT(  BROADCAST );
258 		const char **	cp = STACKLST_OPT( BROADCAST );
259 
260 		while (cn-- > 0) {
261 			handle_lookup(*cp, CTX_BCST);
262 			cp++;
263 		}
264 	}
265 
266 	if (HAVE_OPT(CONCURRENT)) {
267 		int		cn = STACKCT_OPT( CONCURRENT );
268 		const char **	cp = STACKLST_OPT( CONCURRENT );
269 
270 		while (cn-- > 0) {
271 			handle_lookup(*cp, CTX_UCST | CTX_CONC);
272 			cp++;
273 		}
274 	}
275 
276 	for (i = 0; i < argc; ++i)
277 		handle_lookup(argv[i], CTX_UCST);
278 
279 	gettimeofday_cached(base, &start_tv);
280 	event_base_dispatch(base);
281 	event_base_free(base);
282 
283 	if (!time_adjusted &&
284 	    (ENABLED_OPT(STEP) || ENABLED_OPT(SLEW)))
285 		exitcode = 1;
286 	else
287 		exitcode = 0;
288 
289 	return exitcode;
290 }
291 
292 
293 /*
294 ** open sockets and make them non-blocking
295 */
296 void
297 open_sockets(
298 	void
299 	)
300 {
301 	sockaddr_u	name;
302 
303 	if (-1 == sock4) {
304 		sock4 = socket(PF_INET, SOCK_DGRAM, 0);
305 		if (-1 == sock4) {
306 			/* error getting a socket */
307 			msyslog(LOG_ERR, "open_sockets: socket(PF_INET) failed: %m");
308 			exit(1);
309 		}
310 		/* Make it non-blocking */
311 		make_socket_nonblocking(sock4);
312 
313 		/* Let's try using a wildcard... */
314 		ZERO(name);
315 		AF(&name) = AF_INET;
316 		SET_ADDR4N(&name, INADDR_ANY);
317 		SET_PORT(&name, (HAVE_OPT(USERESERVEDPORT) ? 123 : 0));
318 
319 		if (-1 == bind(sock4, &name.sa,
320 			       SOCKLEN(&name))) {
321 			msyslog(LOG_ERR, "open_sockets: bind(sock4) failed: %m");
322 			exit(1);
323 		}
324 
325 		/* Register an NTP callback for recv/timeout */
326 		ev_sock4 = event_new(base, sock4,
327 				     EV_TIMEOUT | EV_READ | EV_PERSIST,
328 				     &sock_cb, NULL);
329 		if (NULL == ev_sock4) {
330 			msyslog(LOG_ERR,
331 				"open_sockets: event_new(base, sock4) failed!");
332 		} else {
333 			event_add(ev_sock4, &wakeup_tv);
334 		}
335 	}
336 
337 	/* We may not always have IPv6... */
338 	if (-1 == sock6 && ipv6_works) {
339 		sock6 = socket(PF_INET6, SOCK_DGRAM, 0);
340 		if (-1 == sock6 && ipv6_works) {
341 			/* error getting a socket */
342 			msyslog(LOG_ERR, "open_sockets: socket(PF_INET6) failed: %m");
343 			exit(1);
344 		}
345 		/* Make it non-blocking */
346 		make_socket_nonblocking(sock6);
347 
348 		/* Let's try using a wildcard... */
349 		ZERO(name);
350 		AF(&name) = AF_INET6;
351 		SET_ADDR6N(&name, in6addr_any);
352 		SET_PORT(&name, (HAVE_OPT(USERESERVEDPORT) ? 123 : 0));
353 
354 		if (-1 == bind(sock6, &name.sa,
355 			       SOCKLEN(&name))) {
356 			msyslog(LOG_ERR, "open_sockets: bind(sock6) failed: %m");
357 			exit(1);
358 		}
359 		/* Register an NTP callback for recv/timeout */
360 		ev_sock6 = event_new(base, sock6,
361 				     EV_TIMEOUT | EV_READ | EV_PERSIST,
362 				     &sock_cb, NULL);
363 		if (NULL == ev_sock6) {
364 			msyslog(LOG_ERR,
365 				"open_sockets: event_new(base, sock6) failed!");
366 		} else {
367 			event_add(ev_sock6, &wakeup_tv);
368 		}
369 	}
370 
371 	return;
372 }
373 
374 
375 /*
376 ** handle_lookup
377 */
378 void
379 handle_lookup(
380 	const char *name,
381 	int flags
382 	)
383 {
384 	struct addrinfo	hints;	/* Local copy is OK */
385 	struct dns_ctx *ctx;
386 	char *		name_copy;
387 	size_t		name_sz;
388 	size_t		octets;
389 
390 	TRACE(1, ("handle_lookup(%s,%#x)\n", name, flags));
391 
392 	ZERO(hints);
393 	hints.ai_family = ai_fam_pref;
394 	hints.ai_flags = AI_CANONNAME | Z_AI_NUMERICSERV;
395 	/*
396 	** Unless we specify a socktype, we'll get at least two
397 	** entries for each address: one for TCP and one for
398 	** UDP. That's not what we want.
399 	*/
400 	hints.ai_socktype = SOCK_DGRAM;
401 	hints.ai_protocol = IPPROTO_UDP;
402 
403 	name_sz = 1 + strlen(name);
404 	octets = sizeof(*ctx) + name_sz;	// Space for a ctx and the name
405 	ctx = emalloc_zero(octets);		// ctx at ctx[0]
406 	name_copy = (char *)(ctx + 1);		// Put the name at ctx[1]
407 	memcpy(name_copy, name, name_sz);	// copy the name to ctx[1]
408 	ctx->name = name_copy;			// point to it...
409 	ctx->flags = flags;
410 	ctx->timeout = response_tv;
411 	ctx->key = NULL;
412 
413 	/* The following should arguably be passed in... */
414 	if (ENABLED_OPT(AUTHENTICATION)) {
415 		ctx->key_id = OPT_VALUE_AUTHENTICATION;
416 		get_key(ctx->key_id, &ctx->key);
417 		if (NULL == ctx->key) {
418 			fprintf(stderr, "%s: Authentication with keyID %d requested, but no matching keyID found in <%s>!\n",
419 				progname, ctx->key_id, OPT_ARG(KEYFILE));
420 			exit(1);
421 		}
422 	} else {
423 		ctx->key_id = -1;
424 	}
425 
426 	++n_pending_dns;
427 	getaddrinfo_sometime(name, "123", &hints, 0,
428 			     &sntp_name_resolved, ctx);
429 }
430 
431 
432 /*
433 ** DNS Callback:
434 ** - For each IP:
435 ** - - open a socket
436 ** - - increment n_pending_ntp
437 ** - - send a request if this is a Unicast callback
438 ** - - queue wait for response
439 ** - decrement n_pending_dns
440 */
441 void
442 sntp_name_resolved(
443 	int			rescode,
444 	int			gai_errno,
445 	void *			context,
446 	const char *		name,
447 	const char *		service,
448 	const struct addrinfo *	hints,
449 	const struct addrinfo *	addr
450 	)
451 {
452 	struct dns_ctx *	dctx;
453 	sent_pkt *		spkt;
454 	const struct addrinfo *	ai;
455 	SOCKET			sock;
456 	u_int			xmt_delay_v4;
457 	u_int			xmt_delay_v6;
458 	u_int			xmt_delay;
459 	size_t			octets;
460 
461 	xmt_delay_v4 = 0;
462 	xmt_delay_v6 = 0;
463 	dctx = context;
464 	if (rescode) {
465 #ifdef EAI_SYSTEM
466 		if (EAI_SYSTEM == rescode) {
467 			errno = gai_errno;
468 			mfprintf(stderr, "%s lookup error %m\n",
469 				 dctx->name);
470 		} else
471 #endif
472 			fprintf(stderr, "%s lookup error %s\n",
473 				dctx->name, gai_strerror(rescode));
474 	} else {
475 		TRACE(3, ("%s [%s]\n", dctx->name,
476 			  (addr->ai_canonname != NULL)
477 			      ? addr->ai_canonname
478 			      : ""));
479 
480 		for (ai = addr; ai != NULL; ai = ai->ai_next) {
481 
482 			if (check_kod(ai))
483 				continue;
484 
485 			switch (ai->ai_family) {
486 
487 			case AF_INET:
488 				sock = sock4;
489 				xmt_delay = xmt_delay_v4;
490 				xmt_delay_v4++;
491 				break;
492 
493 			case AF_INET6:
494 				if (!ipv6_works)
495 					continue;
496 
497 				sock = sock6;
498 				xmt_delay = xmt_delay_v6;
499 				xmt_delay_v6++;
500 				break;
501 
502 			default:
503 				msyslog(LOG_ERR, "sntp_name_resolved: unexpected ai_family: %d",
504 					ai->ai_family);
505 				exit(1);
506 				break;
507 			}
508 
509 			/*
510 			** We're waiting for a response for either unicast
511 			** or broadcast, so...
512 			*/
513 			++n_pending_ntp;
514 
515 			/* If this is for a unicast IP, queue a request */
516 			if (dctx->flags & CTX_UCST) {
517 				spkt = emalloc_zero(sizeof(*spkt));
518 				spkt->dctx = dctx;
519 				octets = min(ai->ai_addrlen, sizeof(spkt->addr));
520 				memcpy(&spkt->addr, ai->ai_addr, octets);
521 				queue_xmt(sock, dctx, spkt, xmt_delay);
522 			}
523 		}
524 	}
525 	/* n_pending_dns really should be >0 here... */
526 	--n_pending_dns;
527 	check_exit_conditions();
528 }
529 
530 
531 /*
532 ** queue_xmt
533 */
534 void
535 queue_xmt(
536 	SOCKET			sock,
537 	struct dns_ctx *	dctx,
538 	sent_pkt *		spkt,
539 	u_int			xmt_delay
540 	)
541 {
542 	sockaddr_u *	dest;
543 	sent_pkt **	pkt_listp;
544 	sent_pkt *	match;
545 	xmt_ctx *	xctx;
546 	struct timeval	start_cb;
547 	struct timeval	delay;
548 
549 	dest = &spkt->addr;
550 	if (IS_IPV6(dest))
551 		pkt_listp = &v6_pkts_list;
552 	else
553 		pkt_listp = &v4_pkts_list;
554 
555 	/* reject attempts to add address already listed */
556 	for (match = *pkt_listp; match != NULL; match = match->link) {
557 		if (ADDR_PORT_EQ(&spkt->addr, &match->addr)) {
558 			if (strcasecmp(spkt->dctx->name,
559 				       match->dctx->name))
560 				printf("%s %s duplicate address from %s ignored.\n",
561 				       sptoa(&match->addr),
562 				       match->dctx->name,
563 				       spkt->dctx->name);
564 			else
565 				printf("%s %s, duplicate address ignored.\n",
566 				       sptoa(&match->addr),
567 				       match->dctx->name);
568 			dec_pending_ntp(spkt->dctx->name, &spkt->addr);
569 			free(spkt);
570 			return;
571 		}
572 	}
573 
574 	LINK_SLIST(*pkt_listp, spkt, link);
575 
576 	xctx = emalloc_zero(sizeof(*xctx));
577 	xctx->sock = sock;
578 	xctx->spkt = spkt;
579 	gettimeofday_cached(base, &start_cb);
580 	xctx->sched = start_cb.tv_sec + (2 * xmt_delay);
581 
582 	LINK_SORT_SLIST(xmt_q, xctx, (xctx->sched < L_S_S_CUR()->sched),
583 			link, xmt_ctx);
584 	if (xmt_q == xctx) {
585 		/*
586 		 * The new entry is the first scheduled.  The timer is
587 		 * either not active or is set for the second xmt
588 		 * context in xmt_q.
589 		 */
590 		if (NULL == ev_xmt_timer)
591 			ev_xmt_timer = event_new(base, INVALID_SOCKET,
592 						 EV_TIMEOUT,
593 						 &xmt_timer_cb, NULL);
594 		if (NULL == ev_xmt_timer) {
595 			msyslog(LOG_ERR,
596 				"queue_xmt: event_new(base, -1, EV_TIMEOUT) failed!");
597 			exit(1);
598 		}
599 		ZERO(delay);
600 		if (xctx->sched > start_cb.tv_sec)
601 			delay.tv_sec = xctx->sched - start_cb.tv_sec;
602 		event_add(ev_xmt_timer, &delay);
603 		TRACE(2, ("queue_xmt: xmt timer for %u usec\n",
604 			  (u_int)delay.tv_usec));
605 	}
606 }
607 
608 
609 /*
610 ** xmt_timer_cb
611 */
612 void
613 xmt_timer_cb(
614 	evutil_socket_t	fd,
615 	short		what,
616 	void *		ctx
617 	)
618 {
619 	struct timeval	start_cb;
620 	struct timeval	delay;
621 	xmt_ctx *	x;
622 
623 	UNUSED_ARG(fd);
624 	UNUSED_ARG(ctx);
625 	DEBUG_INSIST(EV_TIMEOUT == what);
626 
627 	if (NULL == xmt_q || shutting_down)
628 		return;
629 	gettimeofday_cached(base, &start_cb);
630 	if (xmt_q->sched <= start_cb.tv_sec) {
631 		UNLINK_HEAD_SLIST(x, xmt_q, link);
632 		TRACE(2, ("xmt_timer_cb: at .%6.6u -> %s\n",
633 			  (u_int)start_cb.tv_usec, stoa(&x->spkt->addr)));
634 		xmt(x);
635 		free(x);
636 		if (NULL == xmt_q)
637 			return;
638 	}
639 	if (xmt_q->sched <= start_cb.tv_sec) {
640 		event_add(ev_xmt_timer, &gap);
641 		TRACE(2, ("xmt_timer_cb: at .%6.6u gap %6.6u\n",
642 			  (u_int)start_cb.tv_usec,
643 			  (u_int)gap.tv_usec));
644 	} else {
645 		delay.tv_sec = xmt_q->sched - start_cb.tv_sec;
646 		delay.tv_usec = 0;
647 		event_add(ev_xmt_timer, &delay);
648 		TRACE(2, ("xmt_timer_cb: at .%6.6u next %ld seconds\n",
649 			  (u_int)start_cb.tv_usec,
650 			  (long)delay.tv_sec));
651 	}
652 }
653 
654 
655 /*
656 ** xmt()
657 */
658 void
659 xmt(
660 	xmt_ctx *	xctx
661 	)
662 {
663 	SOCKET		sock = xctx->sock;
664 	struct dns_ctx *dctx = xctx->spkt->dctx;
665 	sent_pkt *	spkt = xctx->spkt;
666 	sockaddr_u *	dst = &spkt->addr;
667 	struct timeval	tv_xmt;
668 	struct pkt	x_pkt;
669 	size_t		pkt_len;
670 	int		sent;
671 
672 	if (0 != gettimeofday(&tv_xmt, NULL)) {
673 		msyslog(LOG_ERR,
674 			"xmt: gettimeofday() failed: %m");
675 		exit(1);
676 	}
677 	tv_xmt.tv_sec += JAN_1970;
678 
679 	pkt_len = generate_pkt(&x_pkt, &tv_xmt, dctx->key_id,
680 			       dctx->key);
681 
682 	sent = sendpkt(sock, dst, &x_pkt, pkt_len);
683 	if (sent) {
684 		/* Save the packet we sent... */
685 		memcpy(&spkt->x_pkt, &x_pkt, min(sizeof(spkt->x_pkt),
686 		       pkt_len));
687 		spkt->stime = tv_xmt.tv_sec - JAN_1970;
688 
689 		TRACE(2, ("xmt: %lx.%6.6u %s %s\n", (u_long)tv_xmt.tv_sec,
690 			  (u_int)tv_xmt.tv_usec, dctx->name, stoa(dst)));
691 	} else {
692 		dec_pending_ntp(dctx->name, dst);
693 	}
694 
695 	return;
696 }
697 
698 
699 /*
700  * timeout_queries() -- give up on unrequited NTP queries
701  */
702 void
703 timeout_queries(void)
704 {
705 	struct timeval	start_cb;
706 	u_int		idx;
707 	sent_pkt *	head;
708 	sent_pkt *	spkt;
709 	sent_pkt *	spkt_next;
710 	long		age;
711 	int didsomething = 0;
712 
713 	TRACE(3, ("timeout_queries: called to check %u items\n",
714 		  (unsigned)COUNTOF(fam_listheads)));
715 
716 	gettimeofday_cached(base, &start_cb);
717 	for (idx = 0; idx < COUNTOF(fam_listheads); idx++) {
718 		head = fam_listheads[idx];
719 		for (spkt = head; spkt != NULL; spkt = spkt_next) {
720 			char xcst;
721 
722 			didsomething = 1;
723 			switch (spkt->dctx->flags & CTX_xCST) {
724 			    case CTX_BCST:
725 				xcst = 'B';
726 				break;
727 
728 			    case CTX_UCST:
729 				xcst = 'U';
730 				break;
731 
732 			    default:
733 				INSIST(!"spkt->dctx->flags neither UCST nor BCST");
734 				break;
735 			}
736 
737 			spkt_next = spkt->link;
738 			if (0 == spkt->stime || spkt->done)
739 				continue;
740 			age = start_cb.tv_sec - spkt->stime;
741 			TRACE(3, ("%s %s %cCST age %ld\n",
742 				  stoa(&spkt->addr),
743 				  spkt->dctx->name, xcst, age));
744 			if (age > response_timeout)
745 				timeout_query(spkt);
746 		}
747 	}
748 	// Do we care about didsomething?
749 	TRACE(3, ("timeout_queries: didsomething is %d, age is %ld\n",
750 		  didsomething, (long) (start_cb.tv_sec - start_tv.tv_sec)));
751 	if (start_cb.tv_sec - start_tv.tv_sec > response_timeout) {
752 		TRACE(3, ("timeout_queries: bail!\n"));
753 		event_base_loopexit(base, NULL);
754 		shutting_down = TRUE;
755 	}
756 }
757 
758 
759 void dec_pending_ntp(
760 	const char *	name,
761 	sockaddr_u *	server
762 	)
763 {
764 	if (n_pending_ntp > 0) {
765 		--n_pending_ntp;
766 		check_exit_conditions();
767 	} else {
768 		INSIST(0 == n_pending_ntp);
769 		TRACE(1, ("n_pending_ntp was zero before decrement for %s\n",
770 			  hostnameaddr(name, server)));
771 	}
772 }
773 
774 
775 void timeout_query(
776 	sent_pkt *	spkt
777 	)
778 {
779 	sockaddr_u *	server;
780 	char		xcst;
781 
782 
783 	switch (spkt->dctx->flags & CTX_xCST) {
784 	    case CTX_BCST:
785 		xcst = 'B';
786 		break;
787 
788 	    case CTX_UCST:
789 		xcst = 'U';
790 		break;
791 
792 	    default:
793 		INSIST(!"spkt->dctx->flags neither UCST nor BCST");
794 		break;
795 	}
796 	spkt->done = TRUE;
797 	server = &spkt->addr;
798 	msyslog(LOG_INFO, "%s no %cCST response after %d seconds",
799 		hostnameaddr(spkt->dctx->name, server), xcst,
800 		response_timeout);
801 	dec_pending_ntp(spkt->dctx->name, server);
802 	return;
803 }
804 
805 
806 /*
807 ** check_kod
808 */
809 int
810 check_kod(
811 	const struct addrinfo *	ai
812 	)
813 {
814 	char *hostname;
815 	struct kod_entry *reason;
816 
817 	/* Is there a KoD on file for this address? */
818 	hostname = addrinfo_to_str(ai);
819 	TRACE(2, ("check_kod: checking <%s>\n", hostname));
820 	if (search_entry(hostname, &reason)) {
821 		printf("prior KoD for %s, skipping.\n",
822 			hostname);
823 		free(reason);
824 		free(hostname);
825 
826 		return 1;
827 	}
828 	free(hostname);
829 
830 	return 0;
831 }
832 
833 
834 /*
835 ** Socket readable/timeout Callback:
836 ** Read in the packet
837 ** Unicast:
838 ** - close socket
839 ** - decrement n_pending_ntp
840 ** - If packet is good, set the time and "exit"
841 ** Broadcast:
842 ** - If packet is good, set the time and "exit"
843 */
844 void
845 sock_cb(
846 	evutil_socket_t fd,
847 	short what,
848 	void *ptr
849 	)
850 {
851 	sockaddr_u	sender;
852 	sockaddr_u *	psau;
853 	sent_pkt **	p_pktlist;
854 	sent_pkt *	spkt;
855 	int		rpktl;
856 	int		rc;
857 
858 	INSIST(sock4 == fd || sock6 == fd);
859 
860 	TRACE(3, ("sock_cb: event on sock%s:%s%s%s%s\n",
861 		  (fd == sock6)
862 		      ? "6"
863 		      : "4",
864 		  (what & EV_TIMEOUT) ? " timeout" : "",
865 		  (what & EV_READ)    ? " read" : "",
866 		  (what & EV_WRITE)   ? " write" : "",
867 		  (what & EV_SIGNAL)  ? " signal" : ""));
868 
869 	if (!(EV_READ & what)) {
870 		if (EV_TIMEOUT & what)
871 			timeout_queries();
872 
873 		return;
874 	}
875 
876 	/* Read in the packet */
877 	rpktl = recvdata(fd, &sender, &rbuf, sizeof(rbuf));
878 	if (rpktl < 0) {
879 		msyslog(LOG_DEBUG, "recvfrom error %m");
880 		return;
881 	}
882 
883 	if (sock6 == fd)
884 		p_pktlist = &v6_pkts_list;
885 	else
886 		p_pktlist = &v4_pkts_list;
887 
888 	for (spkt = *p_pktlist; spkt != NULL; spkt = spkt->link) {
889 		psau = &spkt->addr;
890 		if (SOCK_EQ(&sender, psau))
891 			break;
892 	}
893 	if (NULL == spkt) {
894 		msyslog(LOG_WARNING,
895 			"Packet from unexpected source %s dropped",
896 			sptoa(&sender));
897 		return;
898 	}
899 
900 	TRACE(1, ("sock_cb: %s %s\n", spkt->dctx->name,
901 		  sptoa(&sender)));
902 
903 	rpktl = process_pkt(&r_pkt, &sender, rpktl, MODE_SERVER,
904 			    &spkt->x_pkt, "sock_cb");
905 
906 	TRACE(2, ("sock_cb: process_pkt returned %d\n", rpktl));
907 
908 	/* If this is a Unicast packet, one down ... */
909 	if (!spkt->done && (CTX_UCST & spkt->dctx->flags)) {
910 		dec_pending_ntp(spkt->dctx->name, &spkt->addr);
911 		spkt->done = TRUE;
912 	}
913 
914 
915 	/* If the packet is good, set the time and we're all done */
916 	rc = handle_pkt(rpktl, &r_pkt, &spkt->addr, spkt->dctx->name);
917 	if (0 != rc)
918 		TRACE(1, ("sock_cb: handle_pkt() returned %d\n", rc));
919 	check_exit_conditions();
920 }
921 
922 
923 /*
924  * check_exit_conditions()
925  *
926  * If sntp has a reply, ask the event loop to stop after this round of
927  * callbacks, unless --wait was used.
928  */
929 void
930 check_exit_conditions(void)
931 {
932 	if ((0 == n_pending_ntp && 0 == n_pending_dns) ||
933 	    (time_derived && !HAVE_OPT(WAIT))) {
934 		event_base_loopexit(base, NULL);
935 		shutting_down = TRUE;
936 	} else {
937 		TRACE(2, ("%d NTP and %d name queries pending\n",
938 			  n_pending_ntp, n_pending_dns));
939 	}
940 }
941 
942 
943 /*
944  * sntp_addremove_fd() is invoked by the intres blocking worker code
945  * to read from a pipe, or to stop same.
946  */
947 void sntp_addremove_fd(
948 	int	fd,
949 	int	is_pipe,
950 	int	remove_it
951 	)
952 {
953 	u_int		idx;
954 	blocking_child *c;
955 	struct event *	ev;
956 
957 #ifdef HAVE_SOCKETPAIR
958 	if (is_pipe) {
959 		/* sntp only asks for EV_FEATURE_FDS without HAVE_SOCKETPAIR */
960 		msyslog(LOG_ERR, "fatal: pipes not supported on systems with socketpair()");
961 		exit(1);
962 	}
963 #endif
964 
965 	c = NULL;
966 	for (idx = 0; idx < blocking_children_alloc; idx++) {
967 		c = blocking_children[idx];
968 		if (NULL == c)
969 			continue;
970 		if (fd == c->resp_read_pipe)
971 			break;
972 	}
973 	if (idx == blocking_children_alloc)
974 		return;
975 
976 	if (remove_it) {
977 		ev = c->resp_read_ctx;
978 		c->resp_read_ctx = NULL;
979 		event_del(ev);
980 		event_free(ev);
981 
982 		return;
983 	}
984 
985 	ev = event_new(base, fd, EV_READ | EV_PERSIST,
986 		       &worker_resp_cb, c);
987 	if (NULL == ev) {
988 		msyslog(LOG_ERR,
989 			"sntp_addremove_fd: event_new(base, fd) failed!");
990 		return;
991 	}
992 	c->resp_read_ctx = ev;
993 	event_add(ev, NULL);
994 }
995 
996 
997 /* called by forked intres child to close open descriptors */
998 #ifdef WORK_FORK
999 void
1000 kill_asyncio(
1001 	int	startfd
1002 	)
1003 {
1004 	if (INVALID_SOCKET != sock4) {
1005 		closesocket(sock4);
1006 		sock4 = INVALID_SOCKET;
1007 	}
1008 	if (INVALID_SOCKET != sock6) {
1009 		closesocket(sock6);
1010 		sock6 = INVALID_SOCKET;
1011 	}
1012 	if (INVALID_SOCKET != bsock4) {
1013 		closesocket(sock4);
1014 		sock4 = INVALID_SOCKET;
1015 	}
1016 	if (INVALID_SOCKET != bsock6) {
1017 		closesocket(sock6);
1018 		sock6 = INVALID_SOCKET;
1019 	}
1020 }
1021 #endif
1022 
1023 
1024 /*
1025  * worker_resp_cb() is invoked when resp_read_pipe is readable.
1026  */
1027 void
1028 worker_resp_cb(
1029 	evutil_socket_t	fd,
1030 	short		what,
1031 	void *		ctx	/* blocking_child * */
1032 	)
1033 {
1034 	blocking_child *	c;
1035 
1036 	DEBUG_INSIST(EV_READ & what);
1037 	c = ctx;
1038 	DEBUG_INSIST(fd == c->resp_read_pipe);
1039 	process_blocking_resp(c);
1040 }
1041 
1042 
1043 /*
1044  * intres_timeout_req(s) is invoked in the parent to schedule an idle
1045  * timeout to fire in s seconds, if not reset earlier by a call to
1046  * intres_timeout_req(0), which clears any pending timeout.  When the
1047  * timeout expires, worker_idle_timer_fired() is invoked (again, in the
1048  * parent).
1049  *
1050  * sntp and ntpd each provide implementations adapted to their timers.
1051  */
1052 void
1053 intres_timeout_req(
1054 	u_int	seconds		/* 0 cancels */
1055 	)
1056 {
1057 	struct timeval	tv_to;
1058 
1059 	if (NULL == ev_worker_timeout) {
1060 		ev_worker_timeout = event_new(base, -1,
1061 					      EV_TIMEOUT | EV_PERSIST,
1062 					      &worker_timeout, NULL);
1063 		DEBUG_INSIST(NULL != ev_worker_timeout);
1064 	} else {
1065 		event_del(ev_worker_timeout);
1066 	}
1067 	if (0 == seconds)
1068 		return;
1069 	tv_to.tv_sec = seconds;
1070 	tv_to.tv_usec = 0;
1071 	event_add(ev_worker_timeout, &tv_to);
1072 }
1073 
1074 
1075 void
1076 worker_timeout(
1077 	evutil_socket_t	fd,
1078 	short		what,
1079 	void *		ctx
1080 	)
1081 {
1082 	UNUSED_ARG(fd);
1083 	UNUSED_ARG(ctx);
1084 
1085 	DEBUG_REQUIRE(EV_TIMEOUT & what);
1086 	worker_idle_timer_fired();
1087 }
1088 
1089 
1090 void
1091 sntp_libevent_log_cb(
1092 	int		severity,
1093 	const char *	msg
1094 	)
1095 {
1096 	int		level;
1097 
1098 	switch (severity) {
1099 
1100 	default:
1101 	case _EVENT_LOG_DEBUG:
1102 		level = LOG_DEBUG;
1103 		break;
1104 
1105 	case _EVENT_LOG_MSG:
1106 		level = LOG_NOTICE;
1107 		break;
1108 
1109 	case _EVENT_LOG_WARN:
1110 		level = LOG_WARNING;
1111 		break;
1112 
1113 	case _EVENT_LOG_ERR:
1114 		level = LOG_ERR;
1115 		break;
1116 	}
1117 
1118 	msyslog(level, "%s", msg);
1119 }
1120 
1121 
1122 int
1123 generate_pkt (
1124 	struct pkt *x_pkt,
1125 	const struct timeval *tv_xmt,
1126 	int key_id,
1127 	struct key *pkt_key
1128 	)
1129 {
1130 	l_fp	xmt_fp;
1131 	int	pkt_len;
1132 	int	mac_size;
1133 
1134 	pkt_len = LEN_PKT_NOMAC;
1135 	ZERO(*x_pkt);
1136 	TVTOTS(tv_xmt, &xmt_fp);
1137 	HTONL_FP(&xmt_fp, &x_pkt->xmt);
1138 	x_pkt->stratum = STRATUM_TO_PKT(STRATUM_UNSPEC);
1139 	x_pkt->ppoll = 8;
1140 	/* FIXME! Modus broadcast + adr. check -> bdr. pkt */
1141 	set_li_vn_mode(x_pkt, LEAP_NOTINSYNC, ntpver, 3);
1142 	if (debug > 0) {
1143 		printf("generate_pkt: key_id %d, key pointer %p\n", key_id, pkt_key);
1144 	}
1145 	if (pkt_key != NULL) {
1146 		x_pkt->exten[0] = htonl(key_id);
1147 		mac_size = make_mac(x_pkt, pkt_len, MAX_MDG_LEN,
1148 				    pkt_key, (char *)&x_pkt->exten[1]);
1149 		if (mac_size > 0)
1150 			pkt_len += mac_size + KEY_MAC_LEN;
1151 #ifdef DEBUG
1152 		if (debug > 0) {
1153 			printf("generate_pkt: mac_size is %d\n", mac_size);
1154 		}
1155 #endif
1156 
1157 	}
1158 	return pkt_len;
1159 }
1160 
1161 
1162 int
1163 handle_pkt(
1164 	int		rpktl,
1165 	struct pkt *	rpkt,
1166 	sockaddr_u *	host,
1167 	const char *	hostname
1168 	)
1169 {
1170 	char		disptxt[32];
1171 	const char *	addrtxt;
1172 	struct timeval	tv_dst;
1173 	int		cnt;
1174 	int		sw_case;
1175 	int		digits;
1176 	int		stratum;
1177 	char *		ref;
1178 	char *		ts_str;
1179 	const char *	leaptxt;
1180 	double		offset;
1181 	double		precision;
1182 	double		synch_distance;
1183 	char *		p_SNTP_PRETEND_TIME;
1184 	time_t		pretend_time;
1185 #if SIZEOF_TIME_T == 8
1186 	long long	ll;
1187 #else
1188 	long		l;
1189 #endif
1190 
1191 	ts_str = NULL;
1192 
1193 	if (rpktl > 0)
1194 		sw_case = 1;
1195 	else
1196 		sw_case = rpktl;
1197 
1198 	switch (sw_case) {
1199 
1200 	case SERVER_UNUSEABLE:
1201 		return -1;
1202 		break;
1203 
1204 	case PACKET_UNUSEABLE:
1205 		break;
1206 
1207 	case SERVER_AUTH_FAIL:
1208 		break;
1209 
1210 	case KOD_DEMOBILIZE:
1211 		/* Received a DENY or RESTR KOD packet */
1212 		addrtxt = stoa(host);
1213 		ref = (char *)&rpkt->refid;
1214 		add_entry(addrtxt, ref);
1215 		msyslog(LOG_WARNING, "KOD code %c%c%c%c from %s %s",
1216 			ref[0], ref[1], ref[2], ref[3], addrtxt, hostname);
1217 		break;
1218 
1219 	case KOD_RATE:
1220 		/*
1221 		** Hmm...
1222 		** We should probably call add_entry() with an
1223 		** expiration timestamp of several seconds in the future,
1224 		** and back-off even more if we get more RATE responses.
1225 		*/
1226 		break;
1227 
1228 	case 1:
1229 		TRACE(3, ("handle_pkt: %d bytes from %s %s\n",
1230 			  rpktl, stoa(host), hostname));
1231 
1232 		gettimeofday_cached(base, &tv_dst);
1233 
1234 		p_SNTP_PRETEND_TIME = getenv("SNTP_PRETEND_TIME");
1235 		if (p_SNTP_PRETEND_TIME) {
1236 			pretend_time = 0;
1237 #if SIZEOF_TIME_T == 4
1238 			if (1 == sscanf(p_SNTP_PRETEND_TIME, "%ld", &l))
1239 				pretend_time = (time_t)l;
1240 #elif SIZEOF_TIME_T == 8
1241 			if (1 == sscanf(p_SNTP_PRETEND_TIME, "%lld", &ll))
1242 				pretend_time = (time_t)ll;
1243 #else
1244 # include "GRONK: unexpected value for SIZEOF_TIME_T"
1245 #endif
1246 			if (0 != pretend_time)
1247 				tv_dst.tv_sec = pretend_time;
1248 		}
1249 
1250 		offset_calculation(rpkt, rpktl, &tv_dst, &offset,
1251 				   &precision, &synch_distance);
1252 		time_derived = TRUE;
1253 
1254 		for (digits = 0; (precision *= 10.) < 1.; ++digits)
1255 			/* empty */ ;
1256 		if (digits > 6)
1257 			digits = 6;
1258 
1259 		ts_str = tv_to_str(&tv_dst);
1260 		stratum = rpkt->stratum;
1261 		if (0 == stratum)
1262 				stratum = 16;
1263 
1264 		if (synch_distance > 0.) {
1265 			cnt = snprintf(disptxt, sizeof(disptxt),
1266 				       " +/- %f", synch_distance);
1267 			if ((size_t)cnt >= sizeof(disptxt))
1268 				snprintf(disptxt, sizeof(disptxt),
1269 					 "ERROR %d >= %d", cnt,
1270 					 (int)sizeof(disptxt));
1271 		} else {
1272 			disptxt[0] = '\0';
1273 		}
1274 
1275 		switch (PKT_LEAP(rpkt->li_vn_mode)) {
1276 		    case LEAP_NOWARNING:
1277 		    	leaptxt = "no-leap";
1278 			break;
1279 		    case LEAP_ADDSECOND:
1280 		    	leaptxt = "add-leap";
1281 			break;
1282 		    case LEAP_DELSECOND:
1283 		    	leaptxt = "del-leap";
1284 			break;
1285 		    case LEAP_NOTINSYNC:
1286 		    	leaptxt = "unsync";
1287 			break;
1288 		    default:
1289 		    	leaptxt = "LEAP-ERROR";
1290 			break;
1291 		}
1292 
1293 		msyslog(LOG_INFO, "%s %+.*f%s %s s%d %s%s", ts_str,
1294 			digits, offset, disptxt,
1295 			hostnameaddr(hostname, host), stratum,
1296 			leaptxt,
1297 			(time_adjusted)
1298 			    ? " [excess]"
1299 			    : "");
1300 		free(ts_str);
1301 
1302 		if (p_SNTP_PRETEND_TIME)
1303 			return 0;
1304 
1305 		if (!time_adjusted &&
1306 		    (ENABLED_OPT(STEP) || ENABLED_OPT(SLEW)))
1307 			return set_time(offset);
1308 
1309 		return EX_OK;
1310 	}
1311 
1312 	return 1;
1313 }
1314 
1315 
1316 void
1317 offset_calculation(
1318 	struct pkt *rpkt,
1319 	int rpktl,
1320 	struct timeval *tv_dst,
1321 	double *offset,
1322 	double *precision,
1323 	double *synch_distance
1324 	)
1325 {
1326 	l_fp p_rec, p_xmt, p_ref, p_org, tmp, dst;
1327 	u_fp p_rdly, p_rdsp;
1328 	double t21, t34, delta;
1329 
1330 	/* Convert timestamps from network to host byte order */
1331 	p_rdly = NTOHS_FP(rpkt->rootdelay);
1332 	p_rdsp = NTOHS_FP(rpkt->rootdisp);
1333 	NTOHL_FP(&rpkt->reftime, &p_ref);
1334 	NTOHL_FP(&rpkt->org, &p_org);
1335 	NTOHL_FP(&rpkt->rec, &p_rec);
1336 	NTOHL_FP(&rpkt->xmt, &p_xmt);
1337 
1338 	*precision = LOGTOD(rpkt->precision);
1339 
1340 	TRACE(3, ("offset_calculation: LOGTOD(rpkt->precision): %f\n", *precision));
1341 
1342 	/* Compute offset etc. */
1343 	tmp = p_rec;
1344 	L_SUB(&tmp, &p_org);
1345 	LFPTOD(&tmp, t21);
1346 	TVTOTS(tv_dst, &dst);
1347 	dst.l_ui += JAN_1970;
1348 	tmp = p_xmt;
1349 	L_SUB(&tmp, &dst);
1350 	LFPTOD(&tmp, t34);
1351 	*offset = (t21 + t34) / 2.;
1352 	delta = t21 - t34;
1353 
1354 	// synch_distance is:
1355 	// (peer->delay + peer->rootdelay) / 2 + peer->disp
1356 	// + peer->rootdisp + clock_phi * (current_time - peer->update)
1357 	// + peer->jitter;
1358 	//
1359 	// and peer->delay = fabs(peer->offset - p_offset) * 2;
1360 	// and peer->offset needs history, so we're left with
1361 	// p_offset = (t21 + t34) / 2.;
1362 	// peer->disp = 0; (we have no history to augment this)
1363 	// clock_phi = 15e-6;
1364 	// peer->jitter = LOGTOD(sys_precision); (we have no history to augment this)
1365 	// and ntp_proto.c:set_sys_tick_precision() should get us sys_precision.
1366 	//
1367 	// so our answer seems to be:
1368 	//
1369 	// (fabs(t21 + t34) + peer->rootdelay) / 3.
1370 	// + 0 (peer->disp)
1371 	// + peer->rootdisp
1372 	// + 15e-6 (clock_phi)
1373 	// + LOGTOD(sys_precision)
1374 
1375 	INSIST( FPTOD(p_rdly) >= 0. );
1376 #if 1
1377 	*synch_distance = (fabs(t21 + t34) + FPTOD(p_rdly)) / 3.
1378 		+ 0.
1379 		+ FPTOD(p_rdsp)
1380 		+ 15e-6
1381 		+ 0.	/* LOGTOD(sys_precision) when we can get it */
1382 		;
1383 	INSIST( *synch_distance >= 0. );
1384 #else
1385 	*synch_distance = (FPTOD(p_rdly) + FPTOD(p_rdsp))/2.0;
1386 #endif
1387 
1388 #ifdef DEBUG
1389 	if (debug > 3) {
1390 		printf("sntp rootdelay: %f\n", FPTOD(p_rdly));
1391 		printf("sntp rootdisp: %f\n", FPTOD(p_rdsp));
1392 		printf("sntp syncdist: %f\n", *synch_distance);
1393 
1394 		pkt_output(rpkt, rpktl, stdout);
1395 
1396 		printf("sntp offset_calculation: rpkt->reftime:\n");
1397 		l_fp_output(&p_ref, stdout);
1398 		printf("sntp offset_calculation: rpkt->org:\n");
1399 		l_fp_output(&p_org, stdout);
1400 		printf("sntp offset_calculation: rpkt->rec:\n");
1401 		l_fp_output(&p_rec, stdout);
1402 		printf("sntp offset_calculation: rpkt->xmt:\n");
1403 		l_fp_output(&p_xmt, stdout);
1404 	}
1405 #endif
1406 
1407 	TRACE(3, ("sntp offset_calculation:\trec - org t21: %.6f\n"
1408 		  "\txmt - dst t34: %.6f\tdelta: %.6f\toffset: %.6f\n",
1409 		  t21, t34, delta, *offset));
1410 
1411 	return;
1412 }
1413 
1414 
1415 
1416 /* Compute the 8 bits for li_vn_mode */
1417 void
1418 set_li_vn_mode (
1419 	struct pkt *spkt,
1420 	char leap,
1421 	char version,
1422 	char mode
1423 	)
1424 {
1425 	if (leap > 3) {
1426 		msyslog(LOG_DEBUG, "set_li_vn_mode: leap > 3, using max. 3");
1427 		leap = 3;
1428 	}
1429 
1430 	if ((unsigned char)version > 7) {
1431 		msyslog(LOG_DEBUG, "set_li_vn_mode: version < 0 or > 7, using 4");
1432 		version = 4;
1433 	}
1434 
1435 	if (mode > 7) {
1436 		msyslog(LOG_DEBUG, "set_li_vn_mode: mode > 7, using client mode 3");
1437 		mode = 3;
1438 	}
1439 
1440 	spkt->li_vn_mode  = leap << 6;
1441 	spkt->li_vn_mode |= version << 3;
1442 	spkt->li_vn_mode |= mode;
1443 }
1444 
1445 
1446 /*
1447 ** set_time applies 'offset' to the local clock.
1448 */
1449 int
1450 set_time(
1451 	double offset
1452 	)
1453 {
1454 	int rc;
1455 
1456 	if (time_adjusted)
1457 		return EX_OK;
1458 
1459 	/*
1460 	** If we can step but we cannot slew, then step.
1461 	** If we can step or slew and and |offset| > steplimit, then step.
1462 	*/
1463 	if (ENABLED_OPT(STEP) &&
1464 	    (   !ENABLED_OPT(SLEW)
1465 	     || (ENABLED_OPT(SLEW) && (fabs(offset) > steplimit))
1466 	    )) {
1467 		rc = step_systime(offset);
1468 
1469 		/* If there was a problem, can we rely on errno? */
1470 		if (1 == rc)
1471 			time_adjusted = TRUE;
1472 		return (time_adjusted)
1473 			   ? EX_OK
1474 			   : 1;
1475 		/*
1476 		** In case of error, what should we use?
1477 		** EX_UNAVAILABLE?
1478 		** EX_OSERR?
1479 		** EX_NOPERM?
1480 		*/
1481 	}
1482 
1483 	if (ENABLED_OPT(SLEW)) {
1484 		rc = adj_systime(offset);
1485 
1486 		/* If there was a problem, can we rely on errno? */
1487 		if (1 == rc)
1488 			time_adjusted = TRUE;
1489 		return (time_adjusted)
1490 			   ? EX_OK
1491 			   : 1;
1492 		/*
1493 		** In case of error, what should we use?
1494 		** EX_UNAVAILABLE?
1495 		** EX_OSERR?
1496 		** EX_NOPERM?
1497 		*/
1498 	}
1499 
1500 	return EX_SOFTWARE;
1501 }
1502 
1503 
1504 int
1505 libevent_version_ok(void)
1506 {
1507 	ev_uint32_t v_compile_maj;
1508 	ev_uint32_t v_run_maj;
1509 
1510 	v_compile_maj = LIBEVENT_VERSION_NUMBER & 0xffff0000;
1511 	v_run_maj = event_get_version_number() & 0xffff0000;
1512 	if (v_compile_maj != v_run_maj) {
1513 		fprintf(stderr,
1514 			"Incompatible libevent versions: have %s, built with %s\n",
1515 			event_get_version(),
1516 			LIBEVENT_VERSION);
1517 		return 0;
1518 	}
1519 	return 1;
1520 }
1521 
1522 /*
1523  * gettimeofday_cached()
1524  *
1525  * Clones the event_base_gettimeofday_cached() interface but ensures the
1526  * times are always on the gettimeofday() 1970 scale.  Older libevent 2
1527  * sometimes used gettimeofday(), sometimes the since-system-start
1528  * clock_gettime(CLOCK_MONOTONIC), depending on the platform.
1529  *
1530  * It is not cleanly possible to tell which timescale older libevent is
1531  * using.
1532  *
1533  * The strategy involves 1 hour thresholds chosen to be far longer than
1534  * the duration of a round of libevent callbacks, which share a cached
1535  * start-of-round time.  First compare the last cached time with the
1536  * current gettimeofday() time.  If they are within one hour, libevent
1537  * is using the proper timescale so leave the offset 0.  Otherwise,
1538  * compare libevent's cached time and the current time on the monotonic
1539  * scale.  If they are within an hour, libevent is using the monotonic
1540  * scale so calculate the offset to add to such times to bring them to
1541  * gettimeofday()'s scale.
1542  */
1543 int
1544 gettimeofday_cached(
1545 	struct event_base *	b,
1546 	struct timeval *	caller_tv
1547 	)
1548 {
1549 #if defined(_EVENT_HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
1550 	static struct event_base *	cached_b;
1551 	static struct timeval		cached;
1552 	static struct timeval		adj_cached;
1553 	static struct timeval		offset;
1554 	static int			offset_ready;
1555 	struct timeval			latest;
1556 	struct timeval			systemt;
1557 	struct timespec			ts;
1558 	struct timeval			mono;
1559 	struct timeval			diff;
1560 	int				cgt_rc;
1561 	int				gtod_rc;
1562 
1563 	event_base_gettimeofday_cached(b, &latest);
1564 	if (b == cached_b &&
1565 	    !memcmp(&latest, &cached, sizeof(latest))) {
1566 		*caller_tv = adj_cached;
1567 		return 0;
1568 	}
1569 	cached = latest;
1570 	cached_b = b;
1571 	if (!offset_ready) {
1572 		cgt_rc = clock_gettime(CLOCK_MONOTONIC, &ts);
1573 		gtod_rc = gettimeofday(&systemt, NULL);
1574 		if (0 != gtod_rc) {
1575 			msyslog(LOG_ERR,
1576 				"%s: gettimeofday() error %m",
1577 				progname);
1578 			exit(1);
1579 		}
1580 		diff = sub_tval(systemt, latest);
1581 		if (debug > 1)
1582 			printf("system minus cached %+ld.%06ld\n",
1583 			       (long)diff.tv_sec, (long)diff.tv_usec);
1584 		if (0 != cgt_rc || labs((long)diff.tv_sec) < 3600) {
1585 			/*
1586 			 * Either use_monotonic == 0, or this libevent
1587 			 * has been repaired.  Leave offset at zero.
1588 			 */
1589 		} else {
1590 			mono.tv_sec = ts.tv_sec;
1591 			mono.tv_usec = ts.tv_nsec / 1000;
1592 			diff = sub_tval(latest, mono);
1593 			if (debug > 1)
1594 				printf("cached minus monotonic %+ld.%06ld\n",
1595 				       (long)diff.tv_sec, (long)diff.tv_usec);
1596 			if (labs((long)diff.tv_sec) < 3600) {
1597 				/* older libevent2 using monotonic */
1598 				offset = sub_tval(systemt, mono);
1599 				TRACE(1, ("%s: Offsetting libevent CLOCK_MONOTONIC times  by %+ld.%06ld\n",
1600 					 "gettimeofday_cached",
1601 					 (long)offset.tv_sec,
1602 					 (long)offset.tv_usec));
1603 			}
1604 		}
1605 		offset_ready = TRUE;
1606 	}
1607 	adj_cached = add_tval(cached, offset);
1608 	*caller_tv = adj_cached;
1609 
1610 	return 0;
1611 #else
1612 	return event_base_gettimeofday_cached(b, caller_tv);
1613 #endif
1614 }
1615 
1616 /* Dummy function to satisfy libntp/work_fork.c */
1617 extern int set_user_group_ids(void);
1618 int set_user_group_ids(void)
1619 {
1620     return 1;
1621 }
1622