xref: /PHP-7.1/ext/date/lib/parse_tz.c (revision 60a6feed)
1 /*
2  * The MIT License (MIT)
3  *
4  * Copyright (c) 2015 Derick Rethans
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "timelib.h"
26 
27 #include <stdio.h>
28 
29 #ifdef HAVE_LOCALE_H
30 #include <locale.h>
31 #endif
32 
33 #ifdef HAVE_STRING_H
34 #include <string.h>
35 #else
36 #include <strings.h>
37 #endif
38 
39 #define TIMELIB_SUPPORTS_V2DATA
40 #include "timezonedb.h"
41 
42 #if (defined(__APPLE__) || defined(__APPLE_CC__)) && (defined(__BIG_ENDIAN__) || defined(__LITTLE_ENDIAN__))
43 # if defined(__LITTLE_ENDIAN__)
44 #  undef WORDS_BIGENDIAN
45 # else
46 #  if defined(__BIG_ENDIAN__)
47 #   define WORDS_BIGENDIAN
48 #  endif
49 # endif
50 #endif
51 
52 #ifdef WORDS_BIGENDIAN
53 #define timelib_conv_int(l) (l)
54 #else
55 #define timelib_conv_int(l) ((l & 0x000000ff) << 24) + ((l & 0x0000ff00) << 8) + ((l & 0x00ff0000) >> 8) + ((l & 0xff000000) >> 24)
56 #endif
57 
read_preamble(const unsigned char ** tzf,timelib_tzinfo * tz)58 static int read_preamble(const unsigned char **tzf, timelib_tzinfo *tz)
59 {
60 	uint32_t version;
61 
62 	/* read ID */
63 	version = (*tzf)[3] - '0';
64 	*tzf += 4;
65 
66 	/* read BC flag */
67 	tz->bc = (**tzf == '\1');
68 	*tzf += 1;
69 
70 	/* read country code */
71 	memcpy(tz->location.country_code, *tzf, 2);
72 	tz->location.country_code[2] = '\0';
73 	*tzf += 2;
74 
75 	/* skip rest of preamble */
76 	*tzf += 13;
77 
78 	return version;
79 }
80 
read_header(const unsigned char ** tzf,timelib_tzinfo * tz)81 static void read_header(const unsigned char **tzf, timelib_tzinfo *tz)
82 {
83 	uint32_t buffer[6];
84 
85 	memcpy(&buffer, *tzf, sizeof(buffer));
86 	tz->bit32.ttisgmtcnt = timelib_conv_int(buffer[0]);
87 	tz->bit32.ttisstdcnt = timelib_conv_int(buffer[1]);
88 	tz->bit32.leapcnt    = timelib_conv_int(buffer[2]);
89 	tz->bit32.timecnt    = timelib_conv_int(buffer[3]);
90 	tz->bit32.typecnt    = timelib_conv_int(buffer[4]);
91 	tz->bit32.charcnt    = timelib_conv_int(buffer[5]);
92 	*tzf += sizeof(buffer);
93 }
94 
skip_64bit_transistions(const unsigned char ** tzf,timelib_tzinfo * tz)95 static void skip_64bit_transistions(const unsigned char **tzf, timelib_tzinfo *tz)
96 {
97 	if (tz->bit64.timecnt) {
98 		*tzf += (sizeof(int64_t) * tz->bit64.timecnt);
99 		*tzf += (sizeof(unsigned char) * tz->bit64.timecnt);
100 	}
101 }
102 
read_transistions(const unsigned char ** tzf,timelib_tzinfo * tz)103 static void read_transistions(const unsigned char **tzf, timelib_tzinfo *tz)
104 {
105 	int32_t *buffer = NULL;
106 	uint32_t i;
107 	unsigned char *cbuffer = NULL;
108 
109 	if (tz->bit32.timecnt) {
110 		buffer = (int32_t*) timelib_malloc(tz->bit32.timecnt * sizeof(int32_t));
111 		if (!buffer) {
112 			return;
113 		}
114 		memcpy(buffer, *tzf, sizeof(int32_t) * tz->bit32.timecnt);
115 		*tzf += (sizeof(int32_t) * tz->bit32.timecnt);
116 		for (i = 0; i < tz->bit32.timecnt; i++) {
117 			buffer[i] = timelib_conv_int(buffer[i]);
118 		}
119 
120 		cbuffer = (unsigned char*) timelib_malloc(tz->bit32.timecnt * sizeof(unsigned char));
121 		if (!cbuffer) {
122 			timelib_free(buffer);
123 			return;
124 		}
125 		memcpy(cbuffer, *tzf, sizeof(unsigned char) * tz->bit32.timecnt);
126 		*tzf += sizeof(unsigned char) * tz->bit32.timecnt;
127 	}
128 
129 	tz->trans = buffer;
130 	tz->trans_idx = cbuffer;
131 }
132 
skip_64bit_types(const unsigned char ** tzf,timelib_tzinfo * tz)133 static void skip_64bit_types(const unsigned char **tzf, timelib_tzinfo *tz)
134 {
135 	*tzf += sizeof(unsigned char) * 6 * tz->bit64.typecnt;
136 	*tzf += sizeof(char) * tz->bit64.charcnt;
137 	if (tz->bit64.leapcnt) {
138 		*tzf += sizeof(int64_t) * tz->bit64.leapcnt * 2;
139 	}
140 	if (tz->bit64.ttisstdcnt) {
141 		*tzf += sizeof(unsigned char) * tz->bit64.ttisstdcnt;
142 	}
143 	if (tz->bit64.ttisgmtcnt) {
144 		*tzf += sizeof(unsigned char) * tz->bit64.ttisgmtcnt;
145 	}
146 }
147 
read_types(const unsigned char ** tzf,timelib_tzinfo * tz)148 static void read_types(const unsigned char **tzf, timelib_tzinfo *tz)
149 {
150 	unsigned char *buffer;
151 	int32_t *leap_buffer;
152 	unsigned int i, j;
153 
154 	buffer = (unsigned char*) timelib_malloc(tz->bit32.typecnt * sizeof(unsigned char) * 6);
155 	if (!buffer) {
156 		return;
157 	}
158 	memcpy(buffer, *tzf, sizeof(unsigned char) * 6 * tz->bit32.typecnt);
159 	*tzf += sizeof(unsigned char) * 6 * tz->bit32.typecnt;
160 
161 	tz->type = (ttinfo*) timelib_malloc(tz->bit32.typecnt * sizeof(struct ttinfo));
162 	if (!tz->type) {
163 		timelib_free(buffer);
164 		return;
165 	}
166 
167 	for (i = 0; i < tz->bit32.typecnt; i++) {
168 		j = i * 6;
169 		tz->type[i].offset = (buffer[j] * 16777216) + (buffer[j + 1] * 65536) + (buffer[j + 2] * 256) + buffer[j + 3];
170 		tz->type[i].isdst = buffer[j + 4];
171 		tz->type[i].abbr_idx = buffer[j + 5];
172 	}
173 	timelib_free(buffer);
174 
175 	tz->timezone_abbr = (char*) timelib_malloc(tz->bit32.charcnt);
176 	if (!tz->timezone_abbr) {
177 		return;
178 	}
179 	memcpy(tz->timezone_abbr, *tzf, sizeof(char) * tz->bit32.charcnt);
180 	*tzf += sizeof(char) * tz->bit32.charcnt;
181 
182 	if (tz->bit32.leapcnt) {
183 		leap_buffer = (int32_t *) timelib_malloc(tz->bit32.leapcnt * 2 * sizeof(int32_t));
184 		if (!leap_buffer) {
185 			return;
186 		}
187 		memcpy(leap_buffer, *tzf, sizeof(int32_t) * tz->bit32.leapcnt * 2);
188 		*tzf += sizeof(int32_t) * tz->bit32.leapcnt * 2;
189 
190 		tz->leap_times = (tlinfo*) timelib_malloc(tz->bit32.leapcnt * sizeof(tlinfo));
191 		if (!tz->leap_times) {
192 			timelib_free(leap_buffer);
193 			return;
194 		}
195 		for (i = 0; i < tz->bit32.leapcnt; i++) {
196 			tz->leap_times[i].trans = timelib_conv_int(leap_buffer[i * 2]);
197 			tz->leap_times[i].offset = timelib_conv_int(leap_buffer[i * 2 + 1]);
198 		}
199 		timelib_free(leap_buffer);
200 	}
201 
202 	if (tz->bit32.ttisstdcnt) {
203 		buffer = (unsigned char*) timelib_malloc(tz->bit32.ttisstdcnt * sizeof(unsigned char));
204 		if (!buffer) {
205 			return;
206 		}
207 		memcpy(buffer, *tzf, sizeof(unsigned char) * tz->bit32.ttisstdcnt);
208 		*tzf += sizeof(unsigned char) * tz->bit32.ttisstdcnt;
209 
210 		for (i = 0; i < tz->bit32.ttisstdcnt; i++) {
211 			tz->type[i].isstdcnt = buffer[i];
212 		}
213 		timelib_free(buffer);
214 	}
215 
216 	if (tz->bit32.ttisgmtcnt) {
217 		buffer = (unsigned char*) timelib_malloc(tz->bit32.ttisgmtcnt * sizeof(unsigned char));
218 		if (!buffer) {
219 			return;
220 		}
221 		memcpy(buffer, *tzf, sizeof(unsigned char) * tz->bit32.ttisgmtcnt);
222 		*tzf += sizeof(unsigned char) * tz->bit32.ttisgmtcnt;
223 
224 		for (i = 0; i < tz->bit32.ttisgmtcnt; i++) {
225 			tz->type[i].isgmtcnt = buffer[i];
226 		}
227 		timelib_free(buffer);
228 	}
229 }
230 
skip_posix_string(const unsigned char ** tzf,timelib_tzinfo * tz)231 static void skip_posix_string(const unsigned char **tzf, timelib_tzinfo *tz)
232 {
233 	int n_count = 0;
234 
235 	do {
236 		if (*tzf[0] == '\n') {
237 			n_count++;
238 		}
239 		(*tzf)++;
240 	} while (n_count < 2);
241 }
242 
read_location(const unsigned char ** tzf,timelib_tzinfo * tz)243 static void read_location(const unsigned char **tzf, timelib_tzinfo *tz)
244 {
245 	uint32_t buffer[3];
246 	uint32_t comments_len;
247 
248 	memcpy(&buffer, *tzf, sizeof(buffer));
249 	tz->location.latitude = timelib_conv_int(buffer[0]);
250 	tz->location.latitude = (tz->location.latitude / 100000) - 90;
251 	tz->location.longitude = timelib_conv_int(buffer[1]);
252 	tz->location.longitude = (tz->location.longitude / 100000) - 180;
253 	comments_len = timelib_conv_int(buffer[2]);
254 	*tzf += sizeof(buffer);
255 
256 	tz->location.comments = timelib_malloc(comments_len + 1);
257 	memcpy(tz->location.comments, *tzf, comments_len);
258 	tz->location.comments[comments_len] = '\0';
259 	*tzf += comments_len;
260 }
261 
timelib_dump_tzinfo(timelib_tzinfo * tz)262 void timelib_dump_tzinfo(timelib_tzinfo *tz)
263 {
264 	uint32_t i;
265 
266 	printf("Country Code:      %s\n", tz->location.country_code);
267 	printf("Geo Location:      %f,%f\n", tz->location.latitude, tz->location.longitude);
268 	printf("Comments:\n%s\n",          tz->location.comments);
269 	printf("BC:                %s\n",  tz->bc ? "" : "yes");
270 	printf("UTC/Local count:   " TIMELIB_ULONG_FMT "\n", (timelib_ulong) tz->bit32.ttisgmtcnt);
271 	printf("Std/Wall count:    " TIMELIB_ULONG_FMT "\n", (timelib_ulong) tz->bit32.ttisstdcnt);
272 	printf("Leap.sec. count:   " TIMELIB_ULONG_FMT "\n", (timelib_ulong) tz->bit32.leapcnt);
273 	printf("Trans. count:      " TIMELIB_ULONG_FMT "\n", (timelib_ulong) tz->bit32.timecnt);
274 	printf("Local types count: " TIMELIB_ULONG_FMT "\n", (timelib_ulong) tz->bit32.typecnt);
275 	printf("Zone Abbr. count:  " TIMELIB_ULONG_FMT "\n", (timelib_ulong) tz->bit32.charcnt);
276 
277 	printf ("%8s (%12s) = %3d [%5ld %1d %3d '%s' (%d,%d)]\n",
278 		"", "", 0,
279 		(long int) tz->type[0].offset,
280 		tz->type[0].isdst,
281 		tz->type[0].abbr_idx,
282 		&tz->timezone_abbr[tz->type[0].abbr_idx],
283 		tz->type[0].isstdcnt,
284 		tz->type[0].isgmtcnt
285 		);
286 	for (i = 0; i < tz->bit32.timecnt; i++) {
287 		printf ("%08X (%12d) = %3d [%5ld %1d %3d '%s' (%d,%d)]\n",
288 			tz->trans[i], tz->trans[i], tz->trans_idx[i],
289 			(long int) tz->type[tz->trans_idx[i]].offset,
290 			tz->type[tz->trans_idx[i]].isdst,
291 			tz->type[tz->trans_idx[i]].abbr_idx,
292 			&tz->timezone_abbr[tz->type[tz->trans_idx[i]].abbr_idx],
293 			tz->type[tz->trans_idx[i]].isstdcnt,
294 			tz->type[tz->trans_idx[i]].isgmtcnt
295 			);
296 	}
297 	for (i = 0; i < tz->bit32.leapcnt; i++) {
298 		printf ("%08X (%12ld) = %d\n",
299 			tz->leap_times[i].trans,
300 			(long) tz->leap_times[i].trans,
301 			tz->leap_times[i].offset);
302 	}
303 }
304 
seek_to_tz_position(const unsigned char ** tzf,char * timezone,const timelib_tzdb * tzdb)305 static int seek_to_tz_position(const unsigned char **tzf, char *timezone, const timelib_tzdb *tzdb)
306 {
307 	int left = 0, right = tzdb->index_size - 1;
308 #ifdef HAVE_SETLOCALE
309 	char *cur_locale = NULL, *tmp;
310 
311 	tmp = setlocale(LC_CTYPE, NULL);
312 	if (tmp) {
313 		cur_locale = timelib_strdup(tmp);
314 	}
315 	setlocale(LC_CTYPE, "C");
316 #endif
317 
318 	do {
319 		int mid = ((unsigned)left + right) >> 1;
320 		int cmp = strcasecmp(timezone, tzdb->index[mid].id);
321 
322 		if (cmp < 0) {
323 			right = mid - 1;
324 		} else if (cmp > 0) {
325 			left = mid + 1;
326 		} else { /* (cmp == 0) */
327 			(*tzf) = &(tzdb->data[tzdb->index[mid].pos]);
328 #ifdef HAVE_SETLOCALE
329 			setlocale(LC_CTYPE, cur_locale);
330 			if (cur_locale) timelib_free(cur_locale);
331 #endif
332 			return 1;
333 		}
334 
335 	} while (left <= right);
336 
337 #ifdef HAVE_SETLOCALE
338 	setlocale(LC_CTYPE, cur_locale);
339 	if (cur_locale) timelib_free(cur_locale);
340 #endif
341 	return 0;
342 }
343 
timelib_builtin_db(void)344 const timelib_tzdb *timelib_builtin_db(void)
345 {
346 	return &timezonedb_builtin;
347 }
348 
timelib_timezone_builtin_identifiers_list(int * count)349 const timelib_tzdb_index_entry *timelib_timezone_builtin_identifiers_list(int *count)
350 {
351 	*count = sizeof(timezonedb_idx_builtin) / sizeof(*timezonedb_idx_builtin);
352 	return timezonedb_idx_builtin;
353 }
354 
timelib_timezone_id_is_valid(char * timezone,const timelib_tzdb * tzdb)355 int timelib_timezone_id_is_valid(char *timezone, const timelib_tzdb *tzdb)
356 {
357 	const unsigned char *tzf;
358 	return (seek_to_tz_position(&tzf, timezone, tzdb));
359 }
360 
skip_64bit_preamble(const unsigned char ** tzf,timelib_tzinfo * tz)361 static void skip_64bit_preamble(const unsigned char **tzf, timelib_tzinfo *tz)
362 {
363 	*tzf += 20;
364 }
365 
read_64bit_header(const unsigned char ** tzf,timelib_tzinfo * tz)366 static void read_64bit_header(const unsigned char **tzf, timelib_tzinfo *tz)
367 {
368 	uint32_t buffer[6];
369 
370 	memcpy(&buffer, *tzf, sizeof(buffer));
371 	tz->bit64.ttisgmtcnt = timelib_conv_int(buffer[0]);
372 	tz->bit64.ttisstdcnt = timelib_conv_int(buffer[1]);
373 	tz->bit64.leapcnt    = timelib_conv_int(buffer[2]);
374 	tz->bit64.timecnt    = timelib_conv_int(buffer[3]);
375 	tz->bit64.typecnt    = timelib_conv_int(buffer[4]);
376 	tz->bit64.charcnt    = timelib_conv_int(buffer[5]);
377 	*tzf += sizeof(buffer);
378 }
379 
timelib_parse_tzfile(char * timezone,const timelib_tzdb * tzdb)380 timelib_tzinfo *timelib_parse_tzfile(char *timezone, const timelib_tzdb *tzdb)
381 {
382 	const unsigned char *tzf;
383 	timelib_tzinfo *tmp;
384 	int version;
385 
386 	if (seek_to_tz_position(&tzf, timezone, tzdb)) {
387 		tmp = timelib_tzinfo_ctor(timezone);
388 
389 		version = read_preamble(&tzf, tmp);
390 		read_header(&tzf, tmp);
391 		read_transistions(&tzf, tmp);
392 		read_types(&tzf, tmp);
393 		if (version == 2) {
394 			skip_64bit_preamble(&tzf, tmp);
395 			read_64bit_header(&tzf, tmp);
396 			skip_64bit_transistions(&tzf, tmp);
397 			skip_64bit_types(&tzf, tmp);
398 			skip_posix_string(&tzf, tmp);
399 		}
400 		read_location(&tzf, tmp);
401 	} else {
402 		tmp = NULL;
403 	}
404 
405 	return tmp;
406 }
407 
fetch_timezone_offset(timelib_tzinfo * tz,timelib_sll ts,timelib_sll * transition_time)408 static ttinfo* fetch_timezone_offset(timelib_tzinfo *tz, timelib_sll ts, timelib_sll *transition_time)
409 {
410 	uint32_t i;
411 
412 	/* If there is no transition time, we pick the first one, if that doesn't
413 	 * exist we return NULL */
414 	if (!tz->bit32.timecnt || !tz->trans) {
415 		*transition_time = 0;
416 		if (tz->bit32.typecnt == 1) {
417 			return &(tz->type[0]);
418 		}
419 		return NULL;
420 	}
421 
422 	/* If the TS is lower than the first transition time, then we scan over
423 	 * all the transition times to find the first non-DST one, or the first
424 	 * one in case there are only DST entries. Not sure which smartass came up
425 	 * with this idea in the first though :) */
426 	if (ts < tz->trans[0]) {
427 		uint32_t j;
428 
429 		*transition_time = 0;
430 		j = 0;
431 		while (j < tz->bit32.timecnt && tz->type[tz->trans_idx[j]].isdst) {
432 			++j;
433 		}
434 		if (j == tz->bit32.timecnt) {
435 			j = 0;
436 		}
437 		return &(tz->type[tz->trans_idx[j]]);
438 	}
439 
440 	/* In all other cases we loop through the available transtion times to find
441 	 * the correct entry */
442 	for (i = 0; i < tz->bit32.timecnt; i++) {
443 		if (ts < tz->trans[i]) {
444 			*transition_time = tz->trans[i - 1];
445 			return &(tz->type[tz->trans_idx[i - 1]]);
446 		}
447 	}
448 	*transition_time = tz->trans[tz->bit32.timecnt - 1];
449 	return &(tz->type[tz->trans_idx[tz->bit32.timecnt - 1]]);
450 }
451 
fetch_leaptime_offset(timelib_tzinfo * tz,timelib_sll ts)452 static tlinfo* fetch_leaptime_offset(timelib_tzinfo *tz, timelib_sll ts)
453 {
454 	int i;
455 
456 	if (!tz->bit32.leapcnt || !tz->leap_times) {
457 		return NULL;
458 	}
459 
460 	for (i = tz->bit32.leapcnt - 1; i > 0; i--) {
461 		if (ts > tz->leap_times[i].trans) {
462 			return &(tz->leap_times[i]);
463 		}
464 	}
465 	return NULL;
466 }
467 
timelib_timestamp_is_in_dst(timelib_sll ts,timelib_tzinfo * tz)468 int timelib_timestamp_is_in_dst(timelib_sll ts, timelib_tzinfo *tz)
469 {
470 	ttinfo *to;
471 	timelib_sll dummy;
472 
473 	if ((to = fetch_timezone_offset(tz, ts, &dummy))) {
474 		return to->isdst;
475 	}
476 	return -1;
477 }
478 
timelib_get_time_zone_info(timelib_sll ts,timelib_tzinfo * tz)479 timelib_time_offset *timelib_get_time_zone_info(timelib_sll ts, timelib_tzinfo *tz)
480 {
481 	ttinfo *to;
482 	tlinfo *tl;
483 	int32_t offset = 0, leap_secs = 0;
484 	char *abbr;
485 	timelib_time_offset *tmp = timelib_time_offset_ctor();
486 	timelib_sll                transistion_time;
487 
488 	if ((to = fetch_timezone_offset(tz, ts, &transistion_time))) {
489 		offset = to->offset;
490 		abbr = &(tz->timezone_abbr[to->abbr_idx]);
491 		tmp->is_dst = to->isdst;
492 		tmp->transistion_time = transistion_time;
493 	} else {
494 		offset = 0;
495 		abbr = tz->timezone_abbr;
496 		tmp->is_dst = 0;
497 		tmp->transistion_time = 0;
498 	}
499 
500 	if ((tl = fetch_leaptime_offset(tz, ts))) {
501 		leap_secs = -tl->offset;
502 	}
503 
504 	tmp->offset = offset;
505 	tmp->leap_secs = leap_secs;
506 	tmp->abbr = abbr ? timelib_strdup(abbr) : timelib_strdup("GMT");
507 
508 	return tmp;
509 }
510 
timelib_get_current_offset(timelib_time * t)511 timelib_sll timelib_get_current_offset(timelib_time *t)
512 {
513 	timelib_time_offset *gmt_offset;
514 	timelib_sll retval;
515 
516 	switch (t->zone_type) {
517 		case TIMELIB_ZONETYPE_ABBR:
518 		case TIMELIB_ZONETYPE_OFFSET:
519 			return (t->z + t->dst) * -60;
520 
521 		case TIMELIB_ZONETYPE_ID:
522 			gmt_offset = timelib_get_time_zone_info(t->sse, t->tz_info);
523 			retval = gmt_offset->offset;
524 			timelib_time_offset_dtor(gmt_offset);
525 			return retval;
526 
527 		default:
528 			return 0;
529 	}
530 }
531