1/*-
2 * Copyright (c) 2014 Gary Mills
3 * Copyright 2011, Nexenta Systems, Inc.  All rights reserved.
4 * Copyright (c) 1994 Powerdog Industries.  All rights reserved.
5 *
6 * Copyright (c) 2011 The FreeBSD Foundation
7 * All rights reserved.
8 * Portions of this software were developed by David Chisnall
9 * under sponsorship from the FreeBSD Foundation.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer
18 *    in the documentation and/or other materials provided with the
19 *    distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY POWERDOG INDUSTRIES ``AS IS'' AND ANY
22 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE POWERDOG INDUSTRIES BE
25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
28 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
30 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
31 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 *
33 * The views and conclusions contained in the software and documentation
34 * are those of the authors and should not be interpreted as representing
35 * official policies, either expressed or implied, of Powerdog Industries.
36 */
37
38#include <sys/cdefs.h>
39#ifndef lint
40#ifndef NOID
41static char copyright[] __unused =
42"@(#) Copyright (c) 1994 Powerdog Industries.  All rights reserved.";
43static char sccsid[] __unused = "@(#)strptime.c	0.1 (Powerdog) 94/03/27";
44#endif /* !defined NOID */
45#endif /* not lint */
46__FBSDID("$FreeBSD: stable/10/lib/libc/stdtime/strptime.c 306414 2016-09-28 20:49:33Z ache $");
47
48#include "namespace.h"
49#include <time.h>
50#include <ctype.h>
51#include <errno.h>
52#include <stdlib.h>
53#include <string.h>
54#include <pthread.h>
55#include "un-namespace.h"
56#include "libc_private.h"
57#include "timelocal.h"
58#include "tzfile.h"
59
60static char * _strptime(const char *, const char *, struct tm *, int *, locale_t);
61
62#define	asizeof(a)	(sizeof(a) / sizeof((a)[0]))
63
64#define	FLAG_NONE	(1 << 0)
65#define	FLAG_YEAR	(1 << 1)
66#define	FLAG_MONTH	(1 << 2)
67#define	FLAG_YDAY	(1 << 3)
68#define	FLAG_MDAY	(1 << 4)
69#define	FLAG_WDAY	(1 << 5)
70
71/*
72 * Calculate the week day of the first day of a year. Valid for
73 * the Gregorian calendar, which began Sept 14, 1752 in the UK
74 * and its colonies. Ref:
75 * http://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week
76 */
77
78static int
79first_wday_of(int year)
80{
81	return (((2 * (3 - (year / 100) % 4)) + (year % 100) +
82		((year % 100) / 4) + (isleap(year) ? 6 : 0) + 1) % 7);
83}
84
85static char *
86_strptime(const char *buf, const char *fmt, struct tm *tm, int *GMTp,
87		locale_t locale)
88{
89	char	c;
90	const char *ptr;
91	int	day_offset = -1, wday_offset;
92	int week_offset;
93	int	i, len;
94	int flags;
95	int Ealternative, Oalternative;
96	const struct lc_time_T *tptr = __get_current_time_locale(locale);
97	static int start_of_month[2][13] = {
98		{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
99		{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
100	};
101
102	flags = FLAG_NONE;
103
104	ptr = fmt;
105	while (*ptr != 0) {
106		c = *ptr++;
107
108		if (c != '%') {
109			if (isspace_l((unsigned char)c, locale))
110				while (*buf != 0 &&
111				       isspace_l((unsigned char)*buf, locale))
112					buf++;
113			else if (c != *buf++)
114				return (NULL);
115			continue;
116		}
117
118		Ealternative = 0;
119		Oalternative = 0;
120label:
121		c = *ptr++;
122		switch (c) {
123		case '%':
124			if (*buf++ != '%')
125				return (NULL);
126			break;
127
128		case '+':
129			buf = _strptime(buf, tptr->date_fmt, tm, GMTp, locale);
130			if (buf == NULL)
131				return (NULL);
132			flags |= FLAG_WDAY | FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
133			break;
134
135		case 'C':
136			if (!isdigit_l((unsigned char)*buf, locale))
137				return (NULL);
138
139			/* XXX This will break for 3-digit centuries. */
140			len = 2;
141			for (i = 0; len && *buf != 0 &&
142			     isdigit_l((unsigned char)*buf, locale); buf++) {
143				i *= 10;
144				i += *buf - '0';
145				len--;
146			}
147			if (i < 19)
148				return (NULL);
149
150			tm->tm_year = i * 100 - TM_YEAR_BASE;
151			flags |= FLAG_YEAR;
152
153			break;
154
155		case 'c':
156			buf = _strptime(buf, tptr->c_fmt, tm, GMTp, locale);
157			if (buf == NULL)
158				return (NULL);
159			flags |= FLAG_WDAY | FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
160			break;
161
162		case 'D':
163			buf = _strptime(buf, "%m/%d/%y", tm, GMTp, locale);
164			if (buf == NULL)
165				return (NULL);
166			flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
167			break;
168
169		case 'E':
170			if (Ealternative || Oalternative)
171				break;
172			Ealternative++;
173			goto label;
174
175		case 'O':
176			if (Ealternative || Oalternative)
177				break;
178			Oalternative++;
179			goto label;
180
181		case 'F':
182			buf = _strptime(buf, "%Y-%m-%d", tm, GMTp, locale);
183			if (buf == NULL)
184				return (NULL);
185			flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
186			break;
187
188		case 'R':
189			buf = _strptime(buf, "%H:%M", tm, GMTp, locale);
190			if (buf == NULL)
191				return (NULL);
192			break;
193
194		case 'r':
195			buf = _strptime(buf, tptr->ampm_fmt, tm, GMTp, locale);
196			if (buf == NULL)
197				return (NULL);
198			break;
199
200		case 'T':
201			buf = _strptime(buf, "%H:%M:%S", tm, GMTp, locale);
202			if (buf == NULL)
203				return (NULL);
204			break;
205
206		case 'X':
207			buf = _strptime(buf, tptr->X_fmt, tm, GMTp, locale);
208			if (buf == NULL)
209				return (NULL);
210			break;
211
212		case 'x':
213			buf = _strptime(buf, tptr->x_fmt, tm, GMTp, locale);
214			if (buf == NULL)
215				return (NULL);
216			flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
217			break;
218
219		case 'j':
220			if (!isdigit_l((unsigned char)*buf, locale))
221				return (NULL);
222
223			len = 3;
224			for (i = 0; len && *buf != 0 &&
225			     isdigit_l((unsigned char)*buf, locale); buf++){
226				i *= 10;
227				i += *buf - '0';
228				len--;
229			}
230			if (i < 1 || i > 366)
231				return (NULL);
232
233			tm->tm_yday = i - 1;
234			flags |= FLAG_YDAY;
235
236			break;
237
238		case 'M':
239		case 'S':
240			if (*buf == 0 ||
241				isspace_l((unsigned char)*buf, locale))
242				break;
243
244			if (!isdigit_l((unsigned char)*buf, locale))
245				return (NULL);
246
247			len = 2;
248			for (i = 0; len && *buf != 0 &&
249				isdigit_l((unsigned char)*buf, locale); buf++){
250				i *= 10;
251				i += *buf - '0';
252				len--;
253			}
254
255			if (c == 'M') {
256				if (i > 59)
257					return (NULL);
258				tm->tm_min = i;
259			} else {
260				if (i > 60)
261					return (NULL);
262				tm->tm_sec = i;
263			}
264
265			break;
266
267		case 'H':
268		case 'I':
269		case 'k':
270		case 'l':
271			/*
272			 * Of these, %l is the only specifier explicitly
273			 * documented as not being zero-padded.  However,
274			 * there is no harm in allowing zero-padding.
275			 *
276			 * XXX The %l specifier may gobble one too many
277			 * digits if used incorrectly.
278			 */
279			if (!isdigit_l((unsigned char)*buf, locale))
280				return (NULL);
281
282			len = 2;
283			for (i = 0; len && *buf != 0 &&
284			     isdigit_l((unsigned char)*buf, locale); buf++) {
285				i *= 10;
286				i += *buf - '0';
287				len--;
288			}
289			if (c == 'H' || c == 'k') {
290				if (i > 23)
291					return (NULL);
292			} else if (i > 12)
293				return (NULL);
294
295			tm->tm_hour = i;
296
297			break;
298
299		case 'p':
300			/*
301			 * XXX This is bogus if parsed before hour-related
302			 * specifiers.
303			 */
304			if (tm->tm_hour > 12)
305				return (NULL);
306
307			len = strlen(tptr->am);
308			if (strncasecmp_l(buf, tptr->am, len, locale) == 0) {
309				if (tm->tm_hour == 12)
310					tm->tm_hour = 0;
311				buf += len;
312				break;
313			}
314
315			len = strlen(tptr->pm);
316			if (strncasecmp_l(buf, tptr->pm, len, locale) == 0) {
317				if (tm->tm_hour != 12)
318					tm->tm_hour += 12;
319				buf += len;
320				break;
321			}
322
323			return (NULL);
324
325		case 'A':
326		case 'a':
327			for (i = 0; i < asizeof(tptr->weekday); i++) {
328				len = strlen(tptr->weekday[i]);
329				if (strncasecmp_l(buf, tptr->weekday[i],
330						len, locale) == 0)
331					break;
332				len = strlen(tptr->wday[i]);
333				if (strncasecmp_l(buf, tptr->wday[i],
334						len, locale) == 0)
335					break;
336			}
337			if (i == asizeof(tptr->weekday))
338				return (NULL);
339
340			buf += len;
341			tm->tm_wday = i;
342			flags |= FLAG_WDAY;
343			break;
344
345		case 'U':
346		case 'W':
347			/*
348			 * XXX This is bogus, as we can not assume any valid
349			 * information present in the tm structure at this
350			 * point to calculate a real value, so just check the
351			 * range for now.
352			 */
353			if (!isdigit_l((unsigned char)*buf, locale))
354				return (NULL);
355
356			len = 2;
357			for (i = 0; len && *buf != 0 &&
358			     isdigit_l((unsigned char)*buf, locale); buf++) {
359				i *= 10;
360				i += *buf - '0';
361				len--;
362			}
363			if (i > 53)
364				return (NULL);
365
366			if (c == 'U')
367				day_offset = TM_SUNDAY;
368			else
369				day_offset = TM_MONDAY;
370
371
372			week_offset = i;
373
374			break;
375
376		case 'u':
377		case 'w':
378			if (!isdigit_l((unsigned char)*buf, locale))
379				return (NULL);
380
381			i = *buf++ - '0';
382			if (i < 0 || i > 7 || (c == 'u' && i < 1) ||
383			    (c == 'w' && i > 6))
384				return (NULL);
385
386			tm->tm_wday = i % 7;
387			flags |= FLAG_WDAY;
388
389			break;
390
391		case 'e':
392			/*
393			 * With %e format, our strftime(3) adds a blank space
394			 * before single digits.
395			 */
396			if (*buf != 0 &&
397			    isspace_l((unsigned char)*buf, locale))
398			       buf++;
399			/* FALLTHROUGH */
400		case 'd':
401			/*
402			 * The %e specifier was once explicitly documented as
403			 * not being zero-padded but was later changed to
404			 * equivalent to %d.  There is no harm in allowing
405			 * such padding.
406			 *
407			 * XXX The %e specifier may gobble one too many
408			 * digits if used incorrectly.
409			 */
410			if (!isdigit_l((unsigned char)*buf, locale))
411				return (NULL);
412
413			len = 2;
414			for (i = 0; len && *buf != 0 &&
415			     isdigit_l((unsigned char)*buf, locale); buf++) {
416				i *= 10;
417				i += *buf - '0';
418				len--;
419			}
420			if (i > 31)
421				return (NULL);
422
423			tm->tm_mday = i;
424			flags |= FLAG_MDAY;
425
426			break;
427
428		case 'B':
429		case 'b':
430		case 'h':
431			for (i = 0; i < asizeof(tptr->month); i++) {
432				if (Oalternative) {
433					if (c == 'B') {
434						len = strlen(tptr->alt_month[i]);
435						if (strncasecmp_l(buf,
436								tptr->alt_month[i],
437								len, locale) == 0)
438							break;
439					}
440				} else {
441					len = strlen(tptr->month[i]);
442					if (strncasecmp_l(buf, tptr->month[i],
443							len, locale) == 0)
444						break;
445				}
446			}
447			/*
448			 * Try the abbreviated month name if the full name
449			 * wasn't found and Oalternative was not requested.
450			 */
451			if (i == asizeof(tptr->month) && !Oalternative) {
452				for (i = 0; i < asizeof(tptr->month); i++) {
453					len = strlen(tptr->mon[i]);
454					if (strncasecmp_l(buf, tptr->mon[i],
455							len, locale) == 0)
456						break;
457				}
458			}
459			if (i == asizeof(tptr->month))
460				return (NULL);
461
462			tm->tm_mon = i;
463			buf += len;
464			flags |= FLAG_MONTH;
465
466			break;
467
468		case 'm':
469			if (!isdigit_l((unsigned char)*buf, locale))
470				return (NULL);
471
472			len = 2;
473			for (i = 0; len && *buf != 0 &&
474			     isdigit_l((unsigned char)*buf, locale); buf++) {
475				i *= 10;
476				i += *buf - '0';
477				len--;
478			}
479			if (i < 1 || i > 12)
480				return (NULL);
481
482			tm->tm_mon = i - 1;
483			flags |= FLAG_MONTH;
484
485			break;
486
487		case 's':
488			{
489			char *cp;
490			int sverrno;
491			long n;
492			time_t t;
493
494			sverrno = errno;
495			errno = 0;
496			n = strtol_l(buf, &cp, 10, locale);
497			if (errno == ERANGE || (long)(t = n) != n) {
498				errno = sverrno;
499				return (NULL);
500			}
501			errno = sverrno;
502			buf = cp;
503			if (gmtime_r(&t, tm) == NULL)
504				return (NULL);
505			*GMTp = 1;
506			flags |= FLAG_YDAY | FLAG_WDAY | FLAG_MONTH |
507			    FLAG_MDAY | FLAG_YEAR;
508			}
509			break;
510
511		case 'Y':
512		case 'y':
513			if (*buf == 0 ||
514			    isspace_l((unsigned char)*buf, locale))
515				break;
516
517			if (!isdigit_l((unsigned char)*buf, locale))
518				return (NULL);
519
520			len = (c == 'Y') ? 4 : 2;
521			for (i = 0; len && *buf != 0 &&
522			     isdigit_l((unsigned char)*buf, locale); buf++) {
523				i *= 10;
524				i += *buf - '0';
525				len--;
526			}
527			if (c == 'Y')
528				i -= TM_YEAR_BASE;
529			if (c == 'y' && i < 69)
530				i += 100;
531			if (i < 0)
532				return (NULL);
533
534			tm->tm_year = i;
535			flags |= FLAG_YEAR;
536
537			break;
538
539		case 'Z':
540			{
541			const char *cp;
542			char *zonestr;
543
544			for (cp = buf; *cp &&
545			     isupper_l((unsigned char)*cp, locale); ++cp) {
546				/*empty*/}
547			if (cp - buf) {
548				zonestr = alloca(cp - buf + 1);
549				strncpy(zonestr, buf, cp - buf);
550				zonestr[cp - buf] = '\0';
551				tzset();
552				if (0 == strcmp(zonestr, "GMT") ||
553				    0 == strcmp(zonestr, "UTC")) {
554				    *GMTp = 1;
555				} else if (0 == strcmp(zonestr, tzname[0])) {
556				    tm->tm_isdst = 0;
557				} else if (0 == strcmp(zonestr, tzname[1])) {
558				    tm->tm_isdst = 1;
559				} else {
560				    return (NULL);
561				}
562				buf += cp - buf;
563			}
564			}
565			break;
566
567		case 'z':
568			{
569			int sign = 1;
570
571			if (*buf != '+') {
572				if (*buf == '-')
573					sign = -1;
574				else
575					return (NULL);
576			}
577
578			buf++;
579			i = 0;
580			for (len = 4; len > 0; len--) {
581				if (isdigit_l((unsigned char)*buf, locale)) {
582					i *= 10;
583					i += *buf - '0';
584					buf++;
585				} else if (len == 2) {
586					i *= 100;
587					break;
588				} else
589					return (NULL);
590			}
591
592			if (i > 1400 || (sign == -1 && i > 1200) ||
593			    (i % 100) >= 60)
594				return (NULL);
595			tm->tm_hour -= sign * (i / 100);
596			tm->tm_min  -= sign * (i % 100);
597			*GMTp = 1;
598			}
599			break;
600
601		case 'n':
602		case 't':
603			while (isspace_l((unsigned char)*buf, locale))
604				buf++;
605			break;
606
607		default:
608			return (NULL);
609		}
610	}
611
612	if (!(flags & FLAG_YDAY) && (flags & FLAG_YEAR)) {
613		if ((flags & (FLAG_MONTH | FLAG_MDAY)) ==
614		    (FLAG_MONTH | FLAG_MDAY)) {
615			tm->tm_yday = start_of_month[isleap(tm->tm_year +
616			    TM_YEAR_BASE)][tm->tm_mon] + (tm->tm_mday - 1);
617			flags |= FLAG_YDAY;
618		} else if (day_offset != -1) {
619			int tmpwday, tmpyday, fwo;
620
621			fwo = first_wday_of(tm->tm_year + TM_YEAR_BASE);
622			/* No incomplete week (week 0). */
623			if (week_offset == 0 && fwo == day_offset)
624				return (NULL);
625
626			/* Set the date to the first Sunday (or Monday)
627			 * of the specified week of the year.
628			 */
629			tmpwday = (flags & FLAG_WDAY) ? tm->tm_wday :
630			    day_offset;
631			tmpyday = (7 - fwo + day_offset) % 7 +
632			    (week_offset - 1) * 7 +
633			    (tmpwday - day_offset + 7) % 7;
634			/* Impossible yday for incomplete week (week 0). */
635			if (tmpyday < 0) {
636				if (flags & FLAG_WDAY)
637					return (NULL);
638				tmpyday = 0;
639			}
640			tm->tm_yday = tmpyday;
641			flags |= FLAG_YDAY;
642		}
643	}
644
645	if ((flags & (FLAG_YEAR | FLAG_YDAY)) == (FLAG_YEAR | FLAG_YDAY)) {
646		if (!(flags & FLAG_MONTH)) {
647			i = 0;
648			while (tm->tm_yday >=
649			    start_of_month[isleap(tm->tm_year +
650			    TM_YEAR_BASE)][i])
651				i++;
652			if (i > 12) {
653				i = 1;
654				tm->tm_yday -=
655				    start_of_month[isleap(tm->tm_year +
656				    TM_YEAR_BASE)][12];
657				tm->tm_year++;
658			}
659			tm->tm_mon = i - 1;
660			flags |= FLAG_MONTH;
661		}
662		if (!(flags & FLAG_MDAY)) {
663			tm->tm_mday = tm->tm_yday -
664			    start_of_month[isleap(tm->tm_year + TM_YEAR_BASE)]
665			    [tm->tm_mon] + 1;
666			flags |= FLAG_MDAY;
667		}
668		if (!(flags & FLAG_WDAY)) {
669			i = 0;
670			wday_offset = first_wday_of(tm->tm_year);
671			while (i++ <= tm->tm_yday) {
672				if (wday_offset++ >= 6)
673					wday_offset = 0;
674			}
675			tm->tm_wday = wday_offset;
676			flags |= FLAG_WDAY;
677		}
678	}
679
680	return ((char *)buf);
681}
682
683char *
684strptime_l(const char * __restrict buf, const char * __restrict fmt,
685    struct tm * __restrict tm, locale_t loc)
686{
687	char *ret;
688	int gmt;
689	FIX_LOCALE(loc);
690
691	gmt = 0;
692	ret = _strptime(buf, fmt, tm, &gmt, loc);
693	if (ret && gmt) {
694		time_t t = timegm(tm);
695
696		localtime_r(&t, tm);
697	}
698
699	return (ret);
700}
701
702char *
703strptime(const char * __restrict buf, const char * __restrict fmt,
704    struct tm * __restrict tm)
705{
706	return strptime_l(buf, fmt, tm, __get_locale());
707}
708