1 /*
2 * Copyright (C) 2014 Internet Systems Consortium, Inc. ("ISC")
3 *
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
9 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
10 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
11 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
12 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
13 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
14 * PERFORMANCE OF THIS SOFTWARE.
15 */
16
17 /*-
18 * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
19 * All rights reserved.
20 *
21 * This code was contributed to The NetBSD Foundation by Klaus Klein.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the above copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 *
32 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
33 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
34 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
35 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
36 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
37 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
38 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
39 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
40 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
41 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42 * POSSIBILITY OF SUCH DAMAGE.
43 */
44
45 #include <config.h>
46
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <time.h>
51 #include <ctype.h>
52
53 #include <isc/tm.h>
54 #include <isc/util.h>
55
56 /*
57 * Portable conversion routines for struct tm, replacing
58 * timegm() and strptime(), which are not available on all
59 * platforms and don't always behave the same way when they
60 * are.
61 */
62
63 /*
64 * We do not implement alternate representations. However, we always
65 * check whether a given modifier is allowed for a certain conversion.
66 */
67 #define ALT_E 0x01
68 #define ALT_O 0x02
69 #define LEGAL_ALT(x) { if (alt_format & ~(x)) return (0); }
70
71 #ifndef TM_YEAR_BASE
72 #define TM_YEAR_BASE 1900
73 #endif
74
75 static const char *day[7] = {
76 "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday",
77 "Friday", "Saturday"
78 };
79 static const char *abday[7] = {
80 "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
81 };
82 static const char *mon[12] = {
83 "January", "February", "March", "April", "May", "June", "July",
84 "August", "September", "October", "November", "December"
85 };
86 static const char *abmon[12] = {
87 "Jan", "Feb", "Mar", "Apr", "May", "Jun",
88 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
89 };
90 static const char *am_pm[2] = {
91 "AM", "PM"
92 };
93
94 static int
conv_num(const char ** buf,int * dest,int llim,int ulim)95 conv_num(const char **buf, int *dest, int llim, int ulim) {
96 int result = 0;
97
98 /* The limit also determines the number of valid digits. */
99 int rulim = ulim;
100
101 if (**buf < '0' || **buf > '9')
102 return (0);
103
104 do {
105 result *= 10;
106 result += *(*buf)++ - '0';
107 rulim /= 10;
108 } while ((result * 10 <= ulim) &&
109 rulim && **buf >= '0' && **buf <= '9');
110
111 if (result < llim || result > ulim)
112 return (0);
113
114 *dest = result;
115 return (1);
116 }
117
118 time_t
isc_tm_timegm(struct tm * tm)119 isc_tm_timegm(struct tm *tm) {
120 time_t ret;
121 int i, yday = 0, leapday;
122 int mdays[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30 };
123
124 leapday = ((((tm->tm_year + 1900 ) % 4) == 0 &&
125 ((tm->tm_year + 1900 ) % 100) != 0) ||
126 ((tm->tm_year + 1900 ) % 400) == 0) ? 1 : 0;
127 mdays[1] += leapday;
128
129 yday = tm->tm_mday - 1;
130 for (i = 1; i <= tm->tm_mon; i++)
131 yday += mdays[i - 1];
132 ret = tm->tm_sec +
133 (60 * tm->tm_min) +
134 (3600 * tm->tm_hour) +
135 (86400 * (yday +
136 ((tm->tm_year - 70) * 365) +
137 ((tm->tm_year - 69) / 4) -
138 ((tm->tm_year - 1) / 100) +
139 ((tm->tm_year + 299) / 400)));
140 return (ret);
141 }
142
143 char *
isc_tm_strptime(const char * buf,const char * fmt,struct tm * tm)144 isc_tm_strptime(const char *buf, const char *fmt, struct tm *tm) {
145 char c, *ret;
146 const char *bp;
147 size_t len = 0;
148 int alt_format, i, split_year = 0;
149
150 REQUIRE(buf != NULL);
151 REQUIRE(fmt != NULL);
152 REQUIRE(tm != NULL);
153
154 memset(tm, 0, sizeof(struct tm));
155
156 bp = buf;
157
158 while ((c = *fmt) != '\0') {
159 /* Clear `alternate' modifier prior to new conversion. */
160 alt_format = 0;
161
162 /* Eat up white-space. */
163 if (isspace((unsigned char) c)) {
164 while (isspace((unsigned char) *bp))
165 bp++;
166
167 fmt++;
168 continue;
169 }
170
171 if ((c = *fmt++) != '%')
172 goto literal;
173
174
175 again: switch (c = *fmt++) {
176 case '%': /* "%%" is converted to "%". */
177 literal:
178 if (c != *bp++)
179 return (0);
180 break;
181
182 /*
183 * "Alternative" modifiers. Just set the appropriate flag
184 * and start over again.
185 */
186 case 'E': /* "%E?" alternative conversion modifier. */
187 LEGAL_ALT(0);
188 alt_format |= ALT_E;
189 goto again;
190
191 case 'O': /* "%O?" alternative conversion modifier. */
192 LEGAL_ALT(0);
193 alt_format |= ALT_O;
194 goto again;
195
196 /*
197 * "Complex" conversion rules, implemented through recursion.
198 */
199 case 'c': /* Date and time, using the locale's format. */
200 LEGAL_ALT(ALT_E);
201 if (!(bp = isc_tm_strptime(bp, "%x %X", tm)))
202 return (0);
203 break;
204
205 case 'D': /* The date as "%m/%d/%y". */
206 LEGAL_ALT(0);
207 if (!(bp = isc_tm_strptime(bp, "%m/%d/%y", tm)))
208 return (0);
209 break;
210
211 case 'R': /* The time as "%H:%M". */
212 LEGAL_ALT(0);
213 if (!(bp = isc_tm_strptime(bp, "%H:%M", tm)))
214 return (0);
215 break;
216
217 case 'r': /* The time in 12-hour clock representation. */
218 LEGAL_ALT(0);
219 if (!(bp = isc_tm_strptime(bp, "%I:%M:%S %p", tm)))
220 return (0);
221 break;
222
223 case 'T': /* The time as "%H:%M:%S". */
224 LEGAL_ALT(0);
225 if (!(bp = isc_tm_strptime(bp, "%H:%M:%S", tm)))
226 return (0);
227 break;
228
229 case 'X': /* The time, using the locale's format. */
230 LEGAL_ALT(ALT_E);
231 if (!(bp = isc_tm_strptime(bp, "%H:%M:%S", tm)))
232 return (0);
233 break;
234
235 case 'x': /* The date, using the locale's format. */
236 LEGAL_ALT(ALT_E);
237 if (!(bp = isc_tm_strptime(bp, "%m/%d/%y", tm)))
238 return (0);
239 break;
240
241 /*
242 * "Elementary" conversion rules.
243 */
244 case 'A': /* The day of week, using the locale's form. */
245 case 'a':
246 LEGAL_ALT(0);
247 for (i = 0; i < 7; i++) {
248 /* Full name. */
249 len = strlen(day[i]);
250 if (strncasecmp(day[i], bp, len) == 0)
251 break;
252
253 /* Abbreviated name. */
254 len = strlen(abday[i]);
255 if (strncasecmp(abday[i], bp, len) == 0)
256 break;
257 }
258
259 /* Nothing matched. */
260 if (i == 7)
261 return (0);
262
263 tm->tm_wday = i;
264 bp += len;
265 break;
266
267 case 'B': /* The month, using the locale's form. */
268 case 'b':
269 case 'h':
270 LEGAL_ALT(0);
271 for (i = 0; i < 12; i++) {
272 /* Full name. */
273 len = strlen(mon[i]);
274 if (strncasecmp(mon[i], bp, len) == 0)
275 break;
276
277 /* Abbreviated name. */
278 len = strlen(abmon[i]);
279 if (strncasecmp(abmon[i], bp, len) == 0)
280 break;
281 }
282
283 /* Nothing matched. */
284 if (i == 12)
285 return (0);
286
287 tm->tm_mon = i;
288 bp += len;
289 break;
290
291 case 'C': /* The century number. */
292 LEGAL_ALT(ALT_E);
293 if (!(conv_num(&bp, &i, 0, 99)))
294 return (0);
295
296 if (split_year) {
297 tm->tm_year = (tm->tm_year % 100) + (i * 100);
298 } else {
299 tm->tm_year = i * 100;
300 split_year = 1;
301 }
302 break;
303
304 case 'd': /* The day of month. */
305 case 'e':
306 LEGAL_ALT(ALT_O);
307 if (!(conv_num(&bp, &tm->tm_mday, 1, 31)))
308 return (0);
309 break;
310
311 case 'k': /* The hour (24-hour clock representation). */
312 LEGAL_ALT(0);
313 /* FALLTHROUGH */
314 case 'H':
315 LEGAL_ALT(ALT_O);
316 if (!(conv_num(&bp, &tm->tm_hour, 0, 23)))
317 return (0);
318 break;
319
320 case 'l': /* The hour (12-hour clock representation). */
321 LEGAL_ALT(0);
322 /* FALLTHROUGH */
323 case 'I':
324 LEGAL_ALT(ALT_O);
325 if (!(conv_num(&bp, &tm->tm_hour, 1, 12)))
326 return (0);
327 if (tm->tm_hour == 12)
328 tm->tm_hour = 0;
329 break;
330
331 case 'j': /* The day of year. */
332 LEGAL_ALT(0);
333 if (!(conv_num(&bp, &i, 1, 366)))
334 return (0);
335 tm->tm_yday = i - 1;
336 break;
337
338 case 'M': /* The minute. */
339 LEGAL_ALT(ALT_O);
340 if (!(conv_num(&bp, &tm->tm_min, 0, 59)))
341 return (0);
342 break;
343
344 case 'm': /* The month. */
345 LEGAL_ALT(ALT_O);
346 if (!(conv_num(&bp, &i, 1, 12)))
347 return (0);
348 tm->tm_mon = i - 1;
349 break;
350
351 case 'p': /* The locale's equivalent of AM/PM. */
352 LEGAL_ALT(0);
353 /* AM? */
354 if (strcasecmp(am_pm[0], bp) == 0) {
355 if (tm->tm_hour > 11)
356 return (0);
357
358 bp += strlen(am_pm[0]);
359 break;
360 }
361 /* PM? */
362 else if (strcasecmp(am_pm[1], bp) == 0) {
363 if (tm->tm_hour > 11)
364 return (0);
365
366 tm->tm_hour += 12;
367 bp += strlen(am_pm[1]);
368 break;
369 }
370
371 /* Nothing matched. */
372 return (0);
373
374 case 'S': /* The seconds. */
375 LEGAL_ALT(ALT_O);
376 if (!(conv_num(&bp, &tm->tm_sec, 0, 61)))
377 return (0);
378 break;
379
380 case 'U': /* The week of year, beginning on sunday. */
381 case 'W': /* The week of year, beginning on monday. */
382 LEGAL_ALT(ALT_O);
383 /*
384 * XXX This is bogus, as we can not assume any valid
385 * information present in the tm structure at this
386 * point to calculate a real value, so just check the
387 * range for now.
388 */
389 if (!(conv_num(&bp, &i, 0, 53)))
390 return (0);
391 break;
392
393 case 'w': /* The day of week, beginning on sunday. */
394 LEGAL_ALT(ALT_O);
395 if (!(conv_num(&bp, &tm->tm_wday, 0, 6)))
396 return (0);
397 break;
398
399 case 'Y': /* The year. */
400 LEGAL_ALT(ALT_E);
401 if (!(conv_num(&bp, &i, 0, 9999)))
402 return (0);
403
404 tm->tm_year = i - TM_YEAR_BASE;
405 break;
406
407 case 'y': /* The year within 100 years of the epoch. */
408 LEGAL_ALT(ALT_E | ALT_O);
409 if (!(conv_num(&bp, &i, 0, 99)))
410 return (0);
411
412 if (split_year) {
413 tm->tm_year = ((tm->tm_year / 100) * 100) + i;
414 break;
415 }
416 split_year = 1;
417 if (i <= 68)
418 tm->tm_year = i + 2000 - TM_YEAR_BASE;
419 else
420 tm->tm_year = i + 1900 - TM_YEAR_BASE;
421 break;
422
423 /*
424 * Miscellaneous conversions.
425 */
426 case 'n': /* Any kind of white-space. */
427 case 't':
428 LEGAL_ALT(0);
429 while (isspace((unsigned char) *bp))
430 bp++;
431 break;
432
433
434 default: /* Unknown/unsupported conversion. */
435 return (0);
436 }
437
438
439 }
440
441 /* LINTED functional specification */
442 DE_CONST(bp, ret);
443 return (ret);
444 }
445