1 /*
2 * Copyright 2013 Garrett D'Amore <garrett@damore.org>
3 * Copyright 2010 Nexenta Systems, Inc. All rights reserved.
4 * Copyright (c) 1989 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms are permitted
8 * provided that the above copyright notice and this paragraph are
9 * duplicated in all such forms and that any documentation,
10 * advertising materials, and other materials related to such
11 * distribution and use acknowledge that the software was developed
12 * by the University of California, Berkeley. The name of the
13 * University may not be used to endorse or promote products derived
14 * from this software without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
18 */
19
20 #include "lint.h"
21 #include "tzfile.h"
22 #include <fcntl.h>
23 #include <stdint.h>
24 #include <sys/stat.h>
25 #include <string.h>
26 #include <stdio.h>
27 #include <locale.h>
28 #include "timelocal.h"
29 #include "localeimpl.h"
30
31 static char *_add(const char *, char *, const char *);
32 static char *_conv(int, const char *, char *, const char *);
33 static char *_fmt(locale_t, const char *, const struct tm *, char *,
34 const char * const);
35 static char *_yconv(int, int, int, int, char *, const char *);
36
37 extern char *tzname[];
38
39 #define IN_NONE 0
40 #define IN_SOME 1
41 #define IN_THIS 2
42 #define IN_ALL 3
43
44 #define PAD_DEFAULT 0
45 #define PAD_LESS 1
46 #define PAD_SPACE 2
47 #define PAD_ZERO 3
48
49 static const char *fmt_padding[][4] = {
50 /* DEFAULT, LESS, SPACE, ZERO */
51 #define PAD_FMT_MONTHDAY 0
52 #define PAD_FMT_HMS 0
53 #define PAD_FMT_CENTURY 0
54 #define PAD_FMT_SHORTYEAR 0
55 #define PAD_FMT_MONTH 0
56 #define PAD_FMT_WEEKOFYEAR 0
57 #define PAD_FMT_DAYOFMONTH 0
58 { "%02d", "%d", "%2d", "%02d" },
59 #define PAD_FMT_SDAYOFMONTH 1
60 #define PAD_FMT_SHMS 1
61 { "%2d", "%d", "%2d", "%02d" },
62 #define PAD_FMT_DAYOFYEAR 2
63 { "%03d", "%d", "%3d", "%03d" },
64 #define PAD_FMT_YEAR 3
65 { "%04d", "%d", "%4d", "%04d" }
66 };
67
68 /*
69 * If a caller (such as ascftime) passes in a very large maximum size,
70 * the pointer addition here may overflow, wrap around the end of
71 * memory, and, if used as-is, would cause subsequent range checks to fail
72 * spuriously, resulting in corrupted output even if there is sufficent
73 * room in the buffer for the requested format.
74 *
75 * To prevent this, we replace an overflowed result with the largest
76 * possible pointer value.
77 */
78 static char *
_ptlim(char * s,size_t maxsize)79 _ptlim(char *s, size_t maxsize)
80 {
81 char *e = s + maxsize;
82
83 if (e < s)
84 e = (char *)(-sizeof (*e));
85
86 return (e);
87 }
88
89 size_t
strftime_l(char * _RESTRICT_KYWD s,size_t maxsize,const char * _RESTRICT_KYWD format,const struct tm * _RESTRICT_KYWD t,locale_t loc)90 strftime_l(char *_RESTRICT_KYWD s, size_t maxsize,
91 const char *_RESTRICT_KYWD format, const struct tm *_RESTRICT_KYWD t,
92 locale_t loc)
93 {
94 char *p;
95 char *e = _ptlim(s, maxsize);
96
97 tzset();
98 p = _fmt(loc, ((format == NULL) ? "%c" : format), t, s, e);
99 if (p == e)
100 return (0);
101 *p = '\0';
102 return (p - s);
103 }
104
105 size_t
strftime(char * _RESTRICT_KYWD s,size_t maxsize,const char * _RESTRICT_KYWD format,const struct tm * _RESTRICT_KYWD t)106 strftime(char *_RESTRICT_KYWD s, size_t maxsize,
107 const char *_RESTRICT_KYWD format, const struct tm *_RESTRICT_KYWD t)
108 {
109 return (strftime_l(s, maxsize, format, t, uselocale(NULL)));
110 }
111
112 static char *
_fmt(locale_t loc,const char * format,const struct tm * t,char * pt,const char * const ptlim)113 _fmt(locale_t loc, const char *format, const struct tm *t, char *pt,
114 const char * const ptlim)
115 {
116 int Ealternative, Oalternative, PadIndex;
117 const struct lc_time *tptr = loc->time;
118
119 #define PADDING(x) fmt_padding[x][PadIndex]
120
121 for (; *format; ++format) {
122 if (*format == '%') {
123 Ealternative = 0;
124 Oalternative = 0;
125 PadIndex = PAD_DEFAULT;
126 label:
127 switch (*++format) {
128 case '\0':
129 --format;
130 break;
131 case 'A':
132 pt = _add((t->tm_wday < 0 ||
133 t->tm_wday >= DAYSPERWEEK) ?
134 "?" : tptr->weekday[t->tm_wday],
135 pt, ptlim);
136 continue;
137 case 'a':
138 pt = _add((t->tm_wday < 0 ||
139 t->tm_wday >= DAYSPERWEEK) ?
140 "?" : tptr->wday[t->tm_wday],
141 pt, ptlim);
142 continue;
143 case 'B':
144 pt = _add((t->tm_mon < 0 ||
145 t->tm_mon >= MONSPERYEAR) ?
146 "?" : (tptr->month)[t->tm_mon],
147 pt, ptlim);
148 continue;
149 case 'b':
150 case 'h':
151 pt = _add((t->tm_mon < 0 ||
152 t->tm_mon >= MONSPERYEAR) ?
153 "?" : tptr->mon[t->tm_mon],
154 pt, ptlim);
155 continue;
156 case 'C':
157 /*
158 * %C used to do a...
159 * _fmt("%a %b %e %X %Y", t);
160 * ...whereas now POSIX 1003.2 calls for
161 * something completely different.
162 * (ado, 1993-05-24)
163 */
164 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
165 pt, ptlim);
166 continue;
167 case 'c':
168 pt = _fmt(loc, tptr->c_fmt, t, pt, ptlim);
169 continue;
170 case 'D':
171 pt = _fmt(loc, "%m/%d/%y", t, pt, ptlim);
172 continue;
173 case 'd':
174 pt = _conv(t->tm_mday,
175 PADDING(PAD_FMT_DAYOFMONTH), pt, ptlim);
176 continue;
177 case 'E':
178 if (Ealternative || Oalternative)
179 break;
180 Ealternative++;
181 goto label;
182 case 'O':
183 /*
184 * C99 locale modifiers.
185 * The sequences
186 * %Ec %EC %Ex %EX %Ey %EY
187 * %Od %oe %OH %OI %Om %OM
188 * %OS %Ou %OU %OV %Ow %OW %Oy
189 * are supposed to provide alternate
190 * representations.
191 */
192 if (Ealternative || Oalternative)
193 break;
194 Oalternative++;
195 goto label;
196 case 'e':
197 pt = _conv(t->tm_mday,
198 PADDING(PAD_FMT_SDAYOFMONTH), pt, ptlim);
199 continue;
200 case 'F':
201 pt = _fmt(loc, "%Y-%m-%d", t, pt, ptlim);
202 continue;
203 case 'H':
204 pt = _conv(t->tm_hour, PADDING(PAD_FMT_HMS),
205 pt, ptlim);
206 continue;
207 case 'I':
208 pt = _conv((t->tm_hour % 12) ?
209 (t->tm_hour % 12) : 12,
210 PADDING(PAD_FMT_HMS), pt, ptlim);
211 continue;
212 case 'j':
213 pt = _conv(t->tm_yday + 1,
214 PADDING(PAD_FMT_DAYOFYEAR), pt, ptlim);
215 continue;
216 case 'k':
217 /*
218 * This used to be...
219 * _conv(t->tm_hour % 12 ?
220 * t->tm_hour % 12 : 12, 2, ' ');
221 * ...and has been changed to the below to
222 * match SunOS 4.1.1 and Arnold Robbins'
223 * strftime version 3.0. That is, "%k" and
224 * "%l" have been swapped.
225 * (ado, 1993-05-24)
226 */
227 pt = _conv(t->tm_hour,
228 PADDING(PAD_FMT_SHMS), pt, ptlim);
229 continue;
230 case 'l':
231 /*
232 * This used to be...
233 * _conv(t->tm_hour, 2, ' ');
234 * ...and has been changed to the below to
235 * match SunOS 4.1.1 and Arnold Robbin's
236 * strftime version 3.0. That is, "%k" and
237 * "%l" have been swapped.
238 * (ado, 1993-05-24)
239 */
240 pt = _conv((t->tm_hour % 12) ?
241 (t->tm_hour % 12) : 12,
242 PADDING(PAD_FMT_SHMS), pt, ptlim);
243 continue;
244 case 'M':
245 pt = _conv(t->tm_min, PADDING(PAD_FMT_HMS),
246 pt, ptlim);
247 continue;
248 case 'm':
249 pt = _conv(t->tm_mon + 1,
250 PADDING(PAD_FMT_MONTH),
251 pt, ptlim);
252 continue;
253 case 'n':
254 pt = _add("\n", pt, ptlim);
255 continue;
256 case 'p':
257 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
258 tptr->pm : tptr->am, pt, ptlim);
259 continue;
260 case 'R':
261 pt = _fmt(loc, "%H:%M", t, pt, ptlim);
262 continue;
263 case 'r':
264 pt = _fmt(loc, tptr->ampm_fmt, t, pt, ptlim);
265 continue;
266 case 'S':
267 pt = _conv(t->tm_sec, PADDING(PAD_FMT_HMS),
268 pt, ptlim);
269 continue;
270
271 case 's':
272 {
273 struct tm tm;
274 char *buf;
275
276 tm = *t;
277 (void) asprintf(&buf, "%ld", mktime(&tm));
278 pt = _add(buf, pt, ptlim);
279 continue;
280 }
281
282 case 'T':
283 pt = _fmt(loc, "%H:%M:%S", t, pt, ptlim);
284 continue;
285 case 't':
286 pt = _add("\t", pt, ptlim);
287 continue;
288 case 'U':
289 pt = _conv((t->tm_yday + DAYSPERWEEK -
290 t->tm_wday) / DAYSPERWEEK,
291 PADDING(PAD_FMT_WEEKOFYEAR),
292 pt, ptlim);
293 continue;
294 case 'u':
295 /*
296 * From Arnold Robbins' strftime version 3.0:
297 * "ISO 8601: Weekday as a decimal number
298 * [1 (Monday) - 7]"
299 * (ado, 1993-05-24)
300 */
301 pt = _conv((t->tm_wday == 0) ?
302 DAYSPERWEEK : t->tm_wday,
303 "%d", pt, ptlim);
304 continue;
305 case 'V': /* ISO 8601 week number */
306 case 'G': /* ISO 8601 year (four digits) */
307 case 'g': /* ISO 8601 year (two digits) */
308 /*
309 * From Arnold Robbins' strftime version 3.0: "the week number of the
310 * year (the first Monday as the first day of week 1) as a decimal number
311 * (01-53)."
312 * (ado, 1993-05-24)
313 *
314 * From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
315 * "Week 01 of a year is per definition the first week which has the
316 * Thursday in this year, which is equivalent to the week which contains
317 * the fourth day of January. In other words, the first week of a new year
318 * is the week which has the majority of its days in the new year. Week 01
319 * might also contain days from the previous year and the week before week
320 * 01 of a year is the last week (52 or 53) of the previous year even if
321 * it contains days from the new year. A week starts with Monday (day 1)
322 * and ends with Sunday (day 7). For example, the first week of the year
323 * 1997 lasts from 1996-12-30 to 1997-01-05..."
324 * (ado, 1996-01-02)
325 */
326 {
327 int year;
328 int base;
329 int yday;
330 int wday;
331 int w;
332
333 year = t->tm_year;
334 base = TM_YEAR_BASE;
335 yday = t->tm_yday;
336 wday = t->tm_wday;
337 for (;;) {
338 int len;
339 int bot;
340 int top;
341
342 len = isleap_sum(year, base) ?
343 DAYSPERLYEAR : DAYSPERNYEAR;
344 /*
345 * What yday (-3 ... 3) does
346 * the ISO year begin on?
347 */
348 bot = ((yday + 11 - wday) %
349 DAYSPERWEEK) - 3;
350 /*
351 * What yday does the NEXT
352 * ISO year begin on?
353 */
354 top = bot - (len % DAYSPERWEEK);
355 if (top < -3)
356 top += DAYSPERWEEK;
357 top += len;
358 if (yday >= top) {
359 ++base;
360 w = 1;
361 break;
362 }
363 if (yday >= bot) {
364 w = 1 + ((yday - bot) /
365 DAYSPERWEEK);
366 break;
367 }
368 --base;
369 yday += isleap_sum(year, base) ?
370 DAYSPERLYEAR : DAYSPERNYEAR;
371 }
372 #ifdef XPG4_1994_04_09
373 if ((w == 52 && t->tm_mon == TM_JANUARY) ||
374 (w == 1 && t->tm_mon == TM_DECEMBER))
375 w = 53;
376 #endif /* defined XPG4_1994_04_09 */
377 if (*format == 'V')
378 pt = _conv(w,
379 PADDING(PAD_FMT_WEEKOFYEAR),
380 pt, ptlim);
381 else if (*format == 'g') {
382 pt = _yconv(year, base, 0, 1,
383 pt, ptlim);
384 } else
385 pt = _yconv(year, base, 1, 1,
386 pt, ptlim);
387 }
388 continue;
389 case 'v':
390 /*
391 * From Arnold Robbins' strftime version 3.0:
392 * "date as dd-bbb-YYYY"
393 * (ado, 1993-05-24)
394 */
395 pt = _fmt(loc, "%e-%b-%Y", t, pt, ptlim);
396 continue;
397 case 'W':
398 pt = _conv((t->tm_yday + DAYSPERWEEK -
399 (t->tm_wday ?
400 (t->tm_wday - 1) :
401 (DAYSPERWEEK - 1))) / DAYSPERWEEK,
402 PADDING(PAD_FMT_WEEKOFYEAR),
403 pt, ptlim);
404 continue;
405 case 'w':
406 pt = _conv(t->tm_wday, "%d", pt, ptlim);
407 continue;
408 case 'X':
409 pt = _fmt(loc, tptr->X_fmt, t, pt, ptlim);
410 continue;
411 case 'x':
412 pt = _fmt(loc, tptr->x_fmt, t, pt, ptlim);
413 continue;
414 case 'y':
415 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
416 pt, ptlim);
417 continue;
418 case 'Y':
419 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
420 pt, ptlim);
421 continue;
422 case 'Z':
423 if (t->tm_isdst >= 0)
424 pt = _add(tzname[t->tm_isdst != 0],
425 pt, ptlim);
426 /*
427 * C99 says that %Z must be replaced by the
428 * empty string if the time zone is not
429 * determinable.
430 */
431 continue;
432 case 'z':
433 {
434 int diff;
435 char const * sign;
436
437 if (t->tm_isdst < 0)
438 continue;
439 /*
440 * C99 says that the UTC offset must
441 * be computed by looking only at
442 * tm_isdst. This requirement is
443 * incorrect, since it means the code
444 * must rely on magic (in this case
445 * altzone and timezone), and the
446 * magic might not have the correct
447 * offset. Doing things correctly is
448 * tricky and requires disobeying C99;
449 * see GNU C strftime for details.
450 * For now, punt and conform to the
451 * standard, even though it's incorrect.
452 *
453 * C99 says that %z must be replaced by the
454 * empty string if the time zone is not
455 * determinable, so output nothing if the
456 * appropriate variables are not available.
457 */
458 if (t->tm_isdst == 0)
459 diff = -timezone;
460 else
461 diff = -altzone;
462 if (diff < 0) {
463 sign = "-";
464 diff = -diff;
465 } else
466 sign = "+";
467 pt = _add(sign, pt, ptlim);
468 diff /= SECSPERMIN;
469 diff = (diff / MINSPERHOUR) * 100 +
470 (diff % MINSPERHOUR);
471 pt = _conv(diff, PADDING(PAD_FMT_YEAR),
472 pt, ptlim);
473 }
474 continue;
475 case '+':
476 pt = _fmt(loc, tptr->date_fmt, t, pt, ptlim);
477 continue;
478 case '-':
479 if (PadIndex != PAD_DEFAULT)
480 break;
481 PadIndex = PAD_LESS;
482 goto label;
483 case '_':
484 if (PadIndex != PAD_DEFAULT)
485 break;
486 PadIndex = PAD_SPACE;
487 goto label;
488 case '0':
489 if (PadIndex != PAD_DEFAULT)
490 break;
491 PadIndex = PAD_ZERO;
492 goto label;
493 case '%':
494 /*
495 * X311J/88-090 (4.12.3.5): if conversion char is
496 * undefined, behavior is undefined. Print out the
497 * character itself as printf(3) also does.
498 */
499 default:
500 break;
501 }
502 }
503 if (pt == ptlim)
504 break;
505 *pt++ = *format;
506 }
507 return (pt);
508 }
509
510 static char *
_conv(const int n,const char * format,char * const pt,const char * const ptlim)511 _conv(const int n, const char *format, char *const pt,
512 const char *const ptlim)
513 {
514 char buf[12];
515
516 (void) sprintf(buf, format, n);
517 return (_add(buf, pt, ptlim));
518 }
519
520 static char *
_add(const char * str,char * pt,const char * const ptlim)521 _add(const char *str, char *pt, const char *const ptlim)
522 {
523 while (pt < ptlim && (*pt = *str++) != '\0')
524 ++pt;
525 return (pt);
526 }
527
528 /*
529 * POSIX and the C Standard are unclear or inconsistent about
530 * what %C and %y do if the year is negative or exceeds 9999.
531 * Use the convention that %C concatenated with %y yields the
532 * same output as %Y, and that %Y contains at least 4 bytes,
533 * with more only if necessary.
534 */
535
536 static char *
_yconv(const int a,const int b,const int convert_top,const int convert_yy,char * pt,const char * const ptlim)537 _yconv(const int a, const int b, const int convert_top, const int convert_yy,
538 char *pt, const char * const ptlim)
539 {
540 register int lead;
541 register int trail;
542
543 #define DIVISOR 100
544 trail = a % DIVISOR + b % DIVISOR;
545 lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
546 trail %= DIVISOR;
547 if (trail < 0 && lead > 0) {
548 trail += DIVISOR;
549 --lead;
550 } else if (lead < 0 && trail > 0) {
551 trail -= DIVISOR;
552 ++lead;
553 }
554 if (convert_top) {
555 if (lead == 0 && trail < 0)
556 pt = _add("-0", pt, ptlim);
557 else pt = _conv(lead, "%02d", pt, ptlim);
558 }
559 if (convert_yy)
560 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim);
561 return (pt);
562 }
563