xref: /freebsd/contrib/ntp/libntp/lib/isc/unix/time.c (revision 59c8e88e72633afbc47a4ace0d2170d00d51f7dc)
1 /*
2  * Copyright (C) 2004-2008, 2011, 2012  Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (C) 1998-2001, 2003  Internet Software Consortium.
4  *
5  * Permission to use, copy, modify, and/or distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15  * PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 /* $Id$ */
19 
20 /*! \file */
21 
22 #include <config.h>
23 
24 #include <errno.h>
25 #include <limits.h>
26 #include <syslog.h>
27 #include <time.h>
28 
29 #include <sys/time.h>	/* Required for struct timeval on some platforms. */
30 
31 #include <isc/log.h>
32 #include <isc/print.h>
33 #include <isc/strerror.h>
34 #include <isc/string.h>
35 #include <isc/time.h>
36 #include <isc/util.h>
37 
38 #define NS_PER_S	1000000000	/*%< Nanoseconds per second. */
39 #define NS_PER_US	1000		/*%< Nanoseconds per microsecond. */
40 #define US_PER_S	1000000		/*%< Microseconds per second. */
41 
42 /*
43  * All of the INSIST()s checks of nanoseconds < NS_PER_S are for
44  * consistency checking of the type. In lieu of magic numbers, it
45  * is the best we've got.  The check is only performed on functions which
46  * need an initialized type.
47  */
48 
49 #ifndef ISC_FIX_TV_USEC
50 #define ISC_FIX_TV_USEC 1
51 #endif
52 
53 /*%
54  *** Intervals
55  ***/
56 
57 static isc_interval_t zero_interval = { 0, 0 };
58 isc_interval_t *isc_interval_zero = &zero_interval;
59 
60 #if ISC_FIX_TV_USEC
61 static inline void
62 fix_tv_usec(struct timeval *tv) {
63 	isc_boolean_t fixed = ISC_FALSE;
64 
65 	if (tv->tv_usec < 0) {
66 		fixed = ISC_TRUE;
67 		do {
68 			tv->tv_sec -= 1;
69 			tv->tv_usec += US_PER_S;
70 		} while (tv->tv_usec < 0);
71 	} else if (tv->tv_usec >= US_PER_S) {
72 		fixed = ISC_TRUE;
73 		do {
74 			tv->tv_sec += 1;
75 			tv->tv_usec -= US_PER_S;
76 		} while (tv->tv_usec >=US_PER_S);
77 	}
78 	/*
79 	 * Call syslog directly as was are called from the logging functions.
80 	 */
81 	if (fixed)
82 		(void)syslog(LOG_ERR, "gettimeofday returned bad tv_usec: corrected");
83 }
84 #endif
85 
86 void
87 isc_interval_set(isc_interval_t *i,
88 		 unsigned int seconds, unsigned int nanoseconds)
89 {
90 	REQUIRE(i != NULL);
91 	REQUIRE(nanoseconds < NS_PER_S);
92 
93 	i->seconds = seconds;
94 	i->nanoseconds = nanoseconds;
95 }
96 
97 isc_boolean_t
98 isc_interval_iszero(const isc_interval_t *i) {
99 	REQUIRE(i != NULL);
100 	INSIST(i->nanoseconds < NS_PER_S);
101 
102 	if (i->seconds == 0 && i->nanoseconds == 0)
103 		return (ISC_TRUE);
104 
105 	return (ISC_FALSE);
106 }
107 
108 
109 /***
110  *** Absolute Times
111  ***/
112 
113 static isc_time_t epoch = { 0, 0 };
114 isc_time_t *isc_time_epoch = &epoch;
115 
116 void
117 isc_time_set(isc_time_t *t, unsigned int seconds, unsigned int nanoseconds) {
118 	REQUIRE(t != NULL);
119 	REQUIRE(nanoseconds < NS_PER_S);
120 
121 	t->seconds = seconds;
122 	t->nanoseconds = nanoseconds;
123 }
124 
125 void
126 isc_time_settoepoch(isc_time_t *t) {
127 	REQUIRE(t != NULL);
128 
129 	t->seconds = 0;
130 	t->nanoseconds = 0;
131 }
132 
133 isc_boolean_t
134 isc_time_isepoch(const isc_time_t *t) {
135 	REQUIRE(t != NULL);
136 	INSIST(t->nanoseconds < NS_PER_S);
137 
138 	if (t->seconds == 0 && t->nanoseconds == 0)
139 		return (ISC_TRUE);
140 
141 	return (ISC_FALSE);
142 }
143 
144 
145 isc_result_t
146 isc_time_now(isc_time_t *t) {
147 	struct timeval tv;
148 	char strbuf[ISC_STRERRORSIZE];
149 
150 	REQUIRE(t != NULL);
151 
152 	if (gettimeofday(&tv, NULL) == -1) {
153 		isc__strerror(errno, strbuf, sizeof(strbuf));
154 		UNEXPECTED_ERROR(__FILE__, __LINE__, "%s", strbuf);
155 		return (ISC_R_UNEXPECTED);
156 	}
157 
158 	/*
159 	 * Does POSIX guarantee the signedness of tv_sec and tv_usec?  If not,
160 	 * then this test will generate warnings for platforms on which it is
161 	 * unsigned.  In any event, the chances of any of these problems
162 	 * happening are pretty much zero, but since the libisc library ensures
163 	 * certain things to be true ...
164 	 */
165 #if ISC_FIX_TV_USEC
166 	fix_tv_usec(&tv);
167 	if (tv.tv_sec < 0)
168 		return (ISC_R_UNEXPECTED);
169 #else
170 	if (tv.tv_sec < 0 || tv.tv_usec < 0 || tv.tv_usec >= US_PER_S)
171 		return (ISC_R_UNEXPECTED);
172 #endif
173 
174 	/*
175 	 * Ensure the tv_sec value fits in t->seconds.
176 	 */
177 	if (sizeof(tv.tv_sec) > sizeof(t->seconds) &&
178 	    ((tv.tv_sec | (unsigned int)-1) ^ (unsigned int)-1) != 0U)
179 		return (ISC_R_RANGE);
180 
181 	t->seconds = tv.tv_sec;
182 	t->nanoseconds = tv.tv_usec * NS_PER_US;
183 
184 	return (ISC_R_SUCCESS);
185 }
186 
187 isc_result_t
188 isc_time_nowplusinterval(isc_time_t *t, const isc_interval_t *i) {
189 	struct timeval tv;
190 	char strbuf[ISC_STRERRORSIZE];
191 
192 	REQUIRE(t != NULL);
193 	REQUIRE(i != NULL);
194 	INSIST(i->nanoseconds < NS_PER_S);
195 
196 	if (gettimeofday(&tv, NULL) == -1) {
197 		isc__strerror(errno, strbuf, sizeof(strbuf));
198 		UNEXPECTED_ERROR(__FILE__, __LINE__, "%s", strbuf);
199 		return (ISC_R_UNEXPECTED);
200 	}
201 
202 	/*
203 	 * Does POSIX guarantee the signedness of tv_sec and tv_usec?  If not,
204 	 * then this test will generate warnings for platforms on which it is
205 	 * unsigned.  In any event, the chances of any of these problems
206 	 * happening are pretty much zero, but since the libisc library ensures
207 	 * certain things to be true ...
208 	 */
209 #if ISC_FIX_TV_USEC
210 	fix_tv_usec(&tv);
211 	if (tv.tv_sec < 0)
212 		return (ISC_R_UNEXPECTED);
213 #else
214 	if (tv.tv_sec < 0 || tv.tv_usec < 0 || tv.tv_usec >= US_PER_S)
215 		return (ISC_R_UNEXPECTED);
216 #endif
217 
218 	/*
219 	 * Ensure the resulting seconds value fits in the size of an
220 	 * unsigned int.  (It is written this way as a slight optimization;
221 	 * note that even if both values == INT_MAX, then when added
222 	 * and getting another 1 added below the result is UINT_MAX.)
223 	 */
224 	if ((tv.tv_sec > INT_MAX || i->seconds > INT_MAX) &&
225 	    ((long long)tv.tv_sec + i->seconds > UINT_MAX))
226 		return (ISC_R_RANGE);
227 
228 	t->seconds = tv.tv_sec + i->seconds;
229 	t->nanoseconds = tv.tv_usec * NS_PER_US + i->nanoseconds;
230 	if (t->nanoseconds >= NS_PER_S) {
231 		t->seconds++;
232 		t->nanoseconds -= NS_PER_S;
233 	}
234 
235 	return (ISC_R_SUCCESS);
236 }
237 
238 int
239 isc_time_compare(const isc_time_t *t1, const isc_time_t *t2) {
240 	REQUIRE(t1 != NULL && t2 != NULL);
241 	INSIST(t1->nanoseconds < NS_PER_S && t2->nanoseconds < NS_PER_S);
242 
243 	if (t1->seconds < t2->seconds)
244 		return (-1);
245 	if (t1->seconds > t2->seconds)
246 		return (1);
247 	if (t1->nanoseconds < t2->nanoseconds)
248 		return (-1);
249 	if (t1->nanoseconds > t2->nanoseconds)
250 		return (1);
251 	return (0);
252 }
253 
254 isc_result_t
255 isc_time_add(const isc_time_t *t, const isc_interval_t *i, isc_time_t *result)
256 {
257 	REQUIRE(t != NULL && i != NULL && result != NULL);
258 	INSIST(t->nanoseconds < NS_PER_S && i->nanoseconds < NS_PER_S);
259 
260 	/*
261 	 * Ensure the resulting seconds value fits in the size of an
262 	 * unsigned int.  (It is written this way as a slight optimization;
263 	 * note that even if both values == INT_MAX, then when added
264 	 * and getting another 1 added below the result is UINT_MAX.)
265 	 */
266 	if ((t->seconds > INT_MAX || i->seconds > INT_MAX) &&
267 	    ((long long)t->seconds + i->seconds > UINT_MAX))
268 		return (ISC_R_RANGE);
269 
270 	result->seconds = t->seconds + i->seconds;
271 	result->nanoseconds = t->nanoseconds + i->nanoseconds;
272 	if (result->nanoseconds >= NS_PER_S) {
273 		result->seconds++;
274 		result->nanoseconds -= NS_PER_S;
275 	}
276 
277 	return (ISC_R_SUCCESS);
278 }
279 
280 isc_result_t
281 isc_time_subtract(const isc_time_t *t, const isc_interval_t *i,
282 		  isc_time_t *result)
283 {
284 	REQUIRE(t != NULL && i != NULL && result != NULL);
285 	INSIST(t->nanoseconds < NS_PER_S && i->nanoseconds < NS_PER_S);
286 
287 	if ((unsigned int)t->seconds < i->seconds ||
288 	    ((unsigned int)t->seconds == i->seconds &&
289 	     t->nanoseconds < i->nanoseconds))
290 	    return (ISC_R_RANGE);
291 
292 	result->seconds = t->seconds - i->seconds;
293 	if (t->nanoseconds >= i->nanoseconds)
294 		result->nanoseconds = t->nanoseconds - i->nanoseconds;
295 	else {
296 		result->nanoseconds = NS_PER_S - i->nanoseconds +
297 			t->nanoseconds;
298 		result->seconds--;
299 	}
300 
301 	return (ISC_R_SUCCESS);
302 }
303 
304 isc_uint64_t
305 isc_time_microdiff(const isc_time_t *t1, const isc_time_t *t2) {
306 	isc_uint64_t i1, i2, i3;
307 
308 	REQUIRE(t1 != NULL && t2 != NULL);
309 	INSIST(t1->nanoseconds < NS_PER_S && t2->nanoseconds < NS_PER_S);
310 
311 	i1 = (isc_uint64_t)t1->seconds * NS_PER_S + t1->nanoseconds;
312 	i2 = (isc_uint64_t)t2->seconds * NS_PER_S + t2->nanoseconds;
313 
314 	if (i1 <= i2)
315 		return (0);
316 
317 	i3 = i1 - i2;
318 
319 	/*
320 	 * Convert to microseconds.
321 	 */
322 	i3 /= NS_PER_US;
323 
324 	return (i3);
325 }
326 
327 isc_uint32_t
328 isc_time_seconds(const isc_time_t *t) {
329 	REQUIRE(t != NULL);
330 	INSIST(t->nanoseconds < NS_PER_S);
331 
332 	return ((isc_uint32_t)t->seconds);
333 }
334 
335 isc_result_t
336 isc_time_secondsastimet(const isc_time_t *t, time_t *secondsp) {
337 	time_t seconds;
338 
339 	REQUIRE(t != NULL);
340 	INSIST(t->nanoseconds < NS_PER_S);
341 
342 	/*
343 	 * Ensure that the number of seconds represented by t->seconds
344 	 * can be represented by a time_t.  Since t->seconds is an unsigned
345 	 * int and since time_t is mostly opaque, this is trickier than
346 	 * it seems.  (This standardized opaqueness of time_t is *very*
347 	 * frustrating; time_t is not even limited to being an integral
348 	 * type.)
349 	 *
350 	 * The mission, then, is to avoid generating any kind of warning
351 	 * about "signed versus unsigned" while trying to determine if the
352 	 * the unsigned int t->seconds is out range for tv_sec, which is
353 	 * pretty much only true if time_t is a signed integer of the same
354 	 * size as the return value of isc_time_seconds.
355 	 *
356 	 * If the paradox in the if clause below is true, t->seconds is out
357 	 * of range for time_t.
358 	 */
359 	seconds = (time_t)t->seconds;
360 
361 	INSIST(sizeof(unsigned int) == sizeof(isc_uint32_t));
362 	INSIST(sizeof(time_t) >= sizeof(isc_uint32_t));
363 
364 	if (t->seconds > (~0U>>1) && seconds <= (time_t)(~0U>>1))
365 		return (ISC_R_RANGE);
366 
367 	*secondsp = seconds;
368 
369 	return (ISC_R_SUCCESS);
370 }
371 
372 isc_uint32_t
373 isc_time_nanoseconds(const isc_time_t *t) {
374 	REQUIRE(t != NULL);
375 
376 	ENSURE(t->nanoseconds < NS_PER_S);
377 
378 	return ((isc_uint32_t)t->nanoseconds);
379 }
380 
381 void
382 isc_time_formattimestamp(const isc_time_t *t, char *buf, unsigned int len) {
383 	time_t now;
384 	unsigned int flen;
385 
386 	REQUIRE(len > 0);
387 
388 	now = (time_t) t->seconds;
389 	flen = strftime(buf, len, "%d-%b-%Y %X", localtime(&now));
390 	INSIST(flen < len);
391 	if (flen != 0)
392 		snprintf(buf + flen, len - flen,
393 			 ".%03u", t->nanoseconds / 1000000);
394 	else
395 		snprintf(buf, len, "99-Bad-9999 99:99:99.999");
396 }
397 
398 void
399 isc_time_formathttptimestamp(const isc_time_t *t, char *buf, unsigned int len) {
400 	time_t now;
401 	unsigned int flen;
402 
403 	REQUIRE(len > 0);
404 
405 	now = (time_t)t->seconds;
406 	flen = strftime(buf, len, "%a, %d %b %Y %H:%M:%S GMT", gmtime(&now));
407 	INSIST(flen < len);
408 }
409 
410 void
411 isc_time_formatISO8601(const isc_time_t *t, char *buf, unsigned int len) {
412 	time_t now;
413 	unsigned int flen;
414 
415 	REQUIRE(len > 0);
416 
417 	now = (time_t)t->seconds;
418 	flen = strftime(buf, len, "%Y-%m-%dT%H:%M:%SZ", gmtime(&now));
419 	INSIST(flen < len);
420 }
421