parsedate.c 16 KB

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  1. /***************************************************************************
  2. * _ _ ____ _
  3. * Project ___| | | | _ \| |
  4. * / __| | | | |_) | |
  5. * | (__| |_| | _ <| |___
  6. * \___|\___/|_| \_\_____|
  7. *
  8. * Copyright (C) 1998 - 2016, Daniel Stenberg, <[email protected]>, et al.
  9. *
  10. * This software is licensed as described in the file COPYING, which
  11. * you should have received as part of this distribution. The terms
  12. * are also available at https://curl.haxx.se/docs/copyright.html.
  13. *
  14. * You may opt to use, copy, modify, merge, publish, distribute and/or sell
  15. * copies of the Software, and permit persons to whom the Software is
  16. * furnished to do so, under the terms of the COPYING file.
  17. *
  18. * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  19. * KIND, either express or implied.
  20. *
  21. ***************************************************************************/
  22. /*
  23. A brief summary of the date string formats this parser groks:
  24. RFC 2616 3.3.1
  25. Sun, 06 Nov 1994 08:49:37 GMT ; RFC 822, updated by RFC 1123
  26. Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036
  27. Sun Nov 6 08:49:37 1994 ; ANSI C's asctime() format
  28. we support dates without week day name:
  29. 06 Nov 1994 08:49:37 GMT
  30. 06-Nov-94 08:49:37 GMT
  31. Nov 6 08:49:37 1994
  32. without the time zone:
  33. 06 Nov 1994 08:49:37
  34. 06-Nov-94 08:49:37
  35. weird order:
  36. 1994 Nov 6 08:49:37 (GNU date fails)
  37. GMT 08:49:37 06-Nov-94 Sunday
  38. 94 6 Nov 08:49:37 (GNU date fails)
  39. time left out:
  40. 1994 Nov 6
  41. 06-Nov-94
  42. Sun Nov 6 94
  43. unusual separators:
  44. 1994.Nov.6
  45. Sun/Nov/6/94/GMT
  46. commonly used time zone names:
  47. Sun, 06 Nov 1994 08:49:37 CET
  48. 06 Nov 1994 08:49:37 EST
  49. time zones specified using RFC822 style:
  50. Sun, 12 Sep 2004 15:05:58 -0700
  51. Sat, 11 Sep 2004 21:32:11 +0200
  52. compact numerical date strings:
  53. 20040912 15:05:58 -0700
  54. 20040911 +0200
  55. */
  56. #include "curl_setup.h"
  57. #ifdef HAVE_LIMITS_H
  58. #include <limits.h>
  59. #endif
  60. #include <curl/curl.h>
  61. #include "strcase.h"
  62. #include "warnless.h"
  63. #include "parsedate.h"
  64. const char * const Curl_wkday[] =
  65. {"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};
  66. static const char * const weekday[] =
  67. { "Monday", "Tuesday", "Wednesday", "Thursday",
  68. "Friday", "Saturday", "Sunday" };
  69. const char * const Curl_month[]=
  70. { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
  71. "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
  72. struct tzinfo {
  73. char name[5];
  74. int offset; /* +/- in minutes */
  75. };
  76. /*
  77. * parsedate()
  78. *
  79. * Returns:
  80. *
  81. * PARSEDATE_OK - a fine conversion
  82. * PARSEDATE_FAIL - failed to convert
  83. * PARSEDATE_LATER - time overflow at the far end of time_t
  84. * PARSEDATE_SOONER - time underflow at the low end of time_t
  85. */
  86. static int parsedate(const char *date, time_t *output);
  87. #define PARSEDATE_OK 0
  88. #define PARSEDATE_FAIL -1
  89. #define PARSEDATE_LATER 1
  90. #define PARSEDATE_SOONER 2
  91. /* Here's a bunch of frequently used time zone names. These were supported
  92. by the old getdate parser. */
  93. #define tDAYZONE -60 /* offset for daylight savings time */
  94. static const struct tzinfo tz[]= {
  95. {"GMT", 0}, /* Greenwich Mean */
  96. {"UTC", 0}, /* Universal (Coordinated) */
  97. {"WET", 0}, /* Western European */
  98. {"BST", 0 tDAYZONE}, /* British Summer */
  99. {"WAT", 60}, /* West Africa */
  100. {"AST", 240}, /* Atlantic Standard */
  101. {"ADT", 240 tDAYZONE}, /* Atlantic Daylight */
  102. {"EST", 300}, /* Eastern Standard */
  103. {"EDT", 300 tDAYZONE}, /* Eastern Daylight */
  104. {"CST", 360}, /* Central Standard */
  105. {"CDT", 360 tDAYZONE}, /* Central Daylight */
  106. {"MST", 420}, /* Mountain Standard */
  107. {"MDT", 420 tDAYZONE}, /* Mountain Daylight */
  108. {"PST", 480}, /* Pacific Standard */
  109. {"PDT", 480 tDAYZONE}, /* Pacific Daylight */
  110. {"YST", 540}, /* Yukon Standard */
  111. {"YDT", 540 tDAYZONE}, /* Yukon Daylight */
  112. {"HST", 600}, /* Hawaii Standard */
  113. {"HDT", 600 tDAYZONE}, /* Hawaii Daylight */
  114. {"CAT", 600}, /* Central Alaska */
  115. {"AHST", 600}, /* Alaska-Hawaii Standard */
  116. {"NT", 660}, /* Nome */
  117. {"IDLW", 720}, /* International Date Line West */
  118. {"CET", -60}, /* Central European */
  119. {"MET", -60}, /* Middle European */
  120. {"MEWT", -60}, /* Middle European Winter */
  121. {"MEST", -60 tDAYZONE}, /* Middle European Summer */
  122. {"CEST", -60 tDAYZONE}, /* Central European Summer */
  123. {"MESZ", -60 tDAYZONE}, /* Middle European Summer */
  124. {"FWT", -60}, /* French Winter */
  125. {"FST", -60 tDAYZONE}, /* French Summer */
  126. {"EET", -120}, /* Eastern Europe, USSR Zone 1 */
  127. {"WAST", -420}, /* West Australian Standard */
  128. {"WADT", -420 tDAYZONE}, /* West Australian Daylight */
  129. {"CCT", -480}, /* China Coast, USSR Zone 7 */
  130. {"JST", -540}, /* Japan Standard, USSR Zone 8 */
  131. {"EAST", -600}, /* Eastern Australian Standard */
  132. {"EADT", -600 tDAYZONE}, /* Eastern Australian Daylight */
  133. {"GST", -600}, /* Guam Standard, USSR Zone 9 */
  134. {"NZT", -720}, /* New Zealand */
  135. {"NZST", -720}, /* New Zealand Standard */
  136. {"NZDT", -720 tDAYZONE}, /* New Zealand Daylight */
  137. {"IDLE", -720}, /* International Date Line East */
  138. /* Next up: Military timezone names. RFC822 allowed these, but (as noted in
  139. RFC 1123) had their signs wrong. Here we use the correct signs to match
  140. actual military usage.
  141. */
  142. {"A", +1 * 60}, /* Alpha */
  143. {"B", +2 * 60}, /* Bravo */
  144. {"C", +3 * 60}, /* Charlie */
  145. {"D", +4 * 60}, /* Delta */
  146. {"E", +5 * 60}, /* Echo */
  147. {"F", +6 * 60}, /* Foxtrot */
  148. {"G", +7 * 60}, /* Golf */
  149. {"H", +8 * 60}, /* Hotel */
  150. {"I", +9 * 60}, /* India */
  151. /* "J", Juliet is not used as a timezone, to indicate the observer's local
  152. time */
  153. {"K", +10 * 60}, /* Kilo */
  154. {"L", +11 * 60}, /* Lima */
  155. {"M", +12 * 60}, /* Mike */
  156. {"N", -1 * 60}, /* November */
  157. {"O", -2 * 60}, /* Oscar */
  158. {"P", -3 * 60}, /* Papa */
  159. {"Q", -4 * 60}, /* Quebec */
  160. {"R", -5 * 60}, /* Romeo */
  161. {"S", -6 * 60}, /* Sierra */
  162. {"T", -7 * 60}, /* Tango */
  163. {"U", -8 * 60}, /* Uniform */
  164. {"V", -9 * 60}, /* Victor */
  165. {"W", -10 * 60}, /* Whiskey */
  166. {"X", -11 * 60}, /* X-ray */
  167. {"Y", -12 * 60}, /* Yankee */
  168. {"Z", 0}, /* Zulu, zero meridian, a.k.a. UTC */
  169. };
  170. /* returns:
  171. -1 no day
  172. 0 monday - 6 sunday
  173. */
  174. static int checkday(const char *check, size_t len)
  175. {
  176. int i;
  177. const char * const *what;
  178. bool found= FALSE;
  179. if(len > 3)
  180. what = &weekday[0];
  181. else
  182. what = &Curl_wkday[0];
  183. for(i=0; i<7; i++) {
  184. if(strcasecompare(check, what[0])) {
  185. found=TRUE;
  186. break;
  187. }
  188. what++;
  189. }
  190. return found?i:-1;
  191. }
  192. static int checkmonth(const char *check)
  193. {
  194. int i;
  195. const char * const *what;
  196. bool found= FALSE;
  197. what = &Curl_month[0];
  198. for(i=0; i<12; i++) {
  199. if(strcasecompare(check, what[0])) {
  200. found=TRUE;
  201. break;
  202. }
  203. what++;
  204. }
  205. return found?i:-1; /* return the offset or -1, no real offset is -1 */
  206. }
  207. /* return the time zone offset between GMT and the input one, in number
  208. of seconds or -1 if the timezone wasn't found/legal */
  209. static int checktz(const char *check)
  210. {
  211. unsigned int i;
  212. const struct tzinfo *what;
  213. bool found= FALSE;
  214. what = tz;
  215. for(i=0; i< sizeof(tz)/sizeof(tz[0]); i++) {
  216. if(strcasecompare(check, what->name)) {
  217. found=TRUE;
  218. break;
  219. }
  220. what++;
  221. }
  222. return found?what->offset*60:-1;
  223. }
  224. static void skip(const char **date)
  225. {
  226. /* skip everything that aren't letters or digits */
  227. while(**date && !ISALNUM(**date))
  228. (*date)++;
  229. }
  230. enum assume {
  231. DATE_MDAY,
  232. DATE_YEAR,
  233. DATE_TIME
  234. };
  235. /* this is a clone of 'struct tm' but with all fields we don't need or use
  236. cut out */
  237. struct my_tm {
  238. int tm_sec;
  239. int tm_min;
  240. int tm_hour;
  241. int tm_mday;
  242. int tm_mon;
  243. int tm_year;
  244. };
  245. /* struct tm to time since epoch in GMT time zone.
  246. * This is similar to the standard mktime function but for GMT only, and
  247. * doesn't suffer from the various bugs and portability problems that
  248. * some systems' implementations have.
  249. */
  250. static time_t my_timegm(struct my_tm *tm)
  251. {
  252. static const int month_days_cumulative [12] =
  253. { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
  254. int month, year, leap_days;
  255. if(tm->tm_year < 70)
  256. /* we don't support years before 1970 as they will cause this function
  257. to return a negative value */
  258. return -1;
  259. year = tm->tm_year + 1900;
  260. month = tm->tm_mon;
  261. if(month < 0) {
  262. year += (11 - month) / 12;
  263. month = 11 - (11 - month) % 12;
  264. }
  265. else if(month >= 12) {
  266. year -= month / 12;
  267. month = month % 12;
  268. }
  269. leap_days = year - (tm->tm_mon <= 1);
  270. leap_days = ((leap_days / 4) - (leap_days / 100) + (leap_days / 400)
  271. - (1969 / 4) + (1969 / 100) - (1969 / 400));
  272. return ((((time_t) (year - 1970) * 365
  273. + leap_days + month_days_cumulative [month] + tm->tm_mday - 1) * 24
  274. + tm->tm_hour) * 60 + tm->tm_min) * 60 + tm->tm_sec;
  275. }
  276. /*
  277. * parsedate()
  278. *
  279. * Returns:
  280. *
  281. * PARSEDATE_OK - a fine conversion
  282. * PARSEDATE_FAIL - failed to convert
  283. * PARSEDATE_LATER - time overflow at the far end of time_t
  284. * PARSEDATE_SOONER - time underflow at the low end of time_t
  285. */
  286. static int parsedate(const char *date, time_t *output)
  287. {
  288. time_t t = 0;
  289. int wdaynum=-1; /* day of the week number, 0-6 (mon-sun) */
  290. int monnum=-1; /* month of the year number, 0-11 */
  291. int mdaynum=-1; /* day of month, 1 - 31 */
  292. int hournum=-1;
  293. int minnum=-1;
  294. int secnum=-1;
  295. int yearnum=-1;
  296. int tzoff=-1;
  297. struct my_tm tm;
  298. enum assume dignext = DATE_MDAY;
  299. const char *indate = date; /* save the original pointer */
  300. int part = 0; /* max 6 parts */
  301. while(*date && (part < 6)) {
  302. bool found=FALSE;
  303. skip(&date);
  304. if(ISALPHA(*date)) {
  305. /* a name coming up */
  306. char buf[32]="";
  307. size_t len;
  308. if(sscanf(date, "%31[ABCDEFGHIJKLMNOPQRSTUVWXYZ"
  309. "abcdefghijklmnopqrstuvwxyz]", buf))
  310. len = strlen(buf);
  311. else
  312. len = 0;
  313. if(wdaynum == -1) {
  314. wdaynum = checkday(buf, len);
  315. if(wdaynum != -1)
  316. found = TRUE;
  317. }
  318. if(!found && (monnum == -1)) {
  319. monnum = checkmonth(buf);
  320. if(monnum != -1)
  321. found = TRUE;
  322. }
  323. if(!found && (tzoff == -1)) {
  324. /* this just must be a time zone string */
  325. tzoff = checktz(buf);
  326. if(tzoff != -1)
  327. found = TRUE;
  328. }
  329. if(!found)
  330. return PARSEDATE_FAIL; /* bad string */
  331. date += len;
  332. }
  333. else if(ISDIGIT(*date)) {
  334. /* a digit */
  335. int val;
  336. char *end;
  337. int len=0;
  338. if((secnum == -1) &&
  339. (3 == sscanf(date, "%02d:%02d:%02d%n",
  340. &hournum, &minnum, &secnum, &len))) {
  341. /* time stamp! */
  342. date += len;
  343. }
  344. else if((secnum == -1) &&
  345. (2 == sscanf(date, "%02d:%02d%n", &hournum, &minnum, &len))) {
  346. /* time stamp without seconds */
  347. date += len;
  348. secnum = 0;
  349. }
  350. else {
  351. long lval;
  352. int error;
  353. int old_errno;
  354. old_errno = ERRNO;
  355. SET_ERRNO(0);
  356. lval = strtol(date, &end, 10);
  357. error = ERRNO;
  358. if(error != old_errno)
  359. SET_ERRNO(old_errno);
  360. if(error)
  361. return PARSEDATE_FAIL;
  362. #if LONG_MAX != INT_MAX
  363. if((lval > (long)INT_MAX) || (lval < (long)INT_MIN))
  364. return PARSEDATE_FAIL;
  365. #endif
  366. val = curlx_sltosi(lval);
  367. if((tzoff == -1) &&
  368. ((end - date) == 4) &&
  369. (val <= 1400) &&
  370. (indate< date) &&
  371. ((date[-1] == '+' || date[-1] == '-'))) {
  372. /* four digits and a value less than or equal to 1400 (to take into
  373. account all sorts of funny time zone diffs) and it is preceded
  374. with a plus or minus. This is a time zone indication. 1400 is
  375. picked since +1300 is frequently used and +1400 is mentioned as
  376. an edge number in the document "ISO C 200X Proposal: Timezone
  377. Functions" at http://david.tribble.com/text/c0xtimezone.html If
  378. anyone has a more authoritative source for the exact maximum time
  379. zone offsets, please speak up! */
  380. found = TRUE;
  381. tzoff = (val/100 * 60 + val%100)*60;
  382. /* the + and - prefix indicates the local time compared to GMT,
  383. this we need ther reversed math to get what we want */
  384. tzoff = date[-1]=='+'?-tzoff:tzoff;
  385. }
  386. if(((end - date) == 8) &&
  387. (yearnum == -1) &&
  388. (monnum == -1) &&
  389. (mdaynum == -1)) {
  390. /* 8 digits, no year, month or day yet. This is YYYYMMDD */
  391. found = TRUE;
  392. yearnum = val/10000;
  393. monnum = (val%10000)/100-1; /* month is 0 - 11 */
  394. mdaynum = val%100;
  395. }
  396. if(!found && (dignext == DATE_MDAY) && (mdaynum == -1)) {
  397. if((val > 0) && (val<32)) {
  398. mdaynum = val;
  399. found = TRUE;
  400. }
  401. dignext = DATE_YEAR;
  402. }
  403. if(!found && (dignext == DATE_YEAR) && (yearnum == -1)) {
  404. yearnum = val;
  405. found = TRUE;
  406. if(yearnum < 1900) {
  407. if(yearnum > 70)
  408. yearnum += 1900;
  409. else
  410. yearnum += 2000;
  411. }
  412. if(mdaynum == -1)
  413. dignext = DATE_MDAY;
  414. }
  415. if(!found)
  416. return PARSEDATE_FAIL;
  417. date = end;
  418. }
  419. }
  420. part++;
  421. }
  422. if(-1 == secnum)
  423. secnum = minnum = hournum = 0; /* no time, make it zero */
  424. if((-1 == mdaynum) ||
  425. (-1 == monnum) ||
  426. (-1 == yearnum))
  427. /* lacks vital info, fail */
  428. return PARSEDATE_FAIL;
  429. #if SIZEOF_TIME_T < 5
  430. /* 32 bit time_t can only hold dates to the beginning of 2038 */
  431. if(yearnum > 2037) {
  432. *output = 0x7fffffff;
  433. return PARSEDATE_LATER;
  434. }
  435. #endif
  436. if(yearnum < 1970) {
  437. *output = 0;
  438. return PARSEDATE_SOONER;
  439. }
  440. if((mdaynum > 31) || (monnum > 11) ||
  441. (hournum > 23) || (minnum > 59) || (secnum > 60))
  442. return PARSEDATE_FAIL; /* clearly an illegal date */
  443. tm.tm_sec = secnum;
  444. tm.tm_min = minnum;
  445. tm.tm_hour = hournum;
  446. tm.tm_mday = mdaynum;
  447. tm.tm_mon = monnum;
  448. tm.tm_year = yearnum - 1900;
  449. /* my_timegm() returns a time_t. time_t is often 32 bits, even on many
  450. architectures that feature 64 bit 'long'.
  451. Some systems have 64 bit time_t and deal with years beyond 2038. However,
  452. even on some of the systems with 64 bit time_t mktime() returns -1 for
  453. dates beyond 03:14:07 UTC, January 19, 2038. (Such as AIX 5100-06)
  454. */
  455. t = my_timegm(&tm);
  456. /* time zone adjust (cast t to int to compare to negative one) */
  457. if(-1 != (int)t) {
  458. /* Add the time zone diff between local time zone and GMT. */
  459. long delta = (long)(tzoff!=-1?tzoff:0);
  460. if((delta>0) && (t > LONG_MAX - delta)) {
  461. *output = 0x7fffffff;
  462. return PARSEDATE_LATER; /* time_t overflow */
  463. }
  464. t += delta;
  465. }
  466. *output = t;
  467. return PARSEDATE_OK;
  468. }
  469. time_t curl_getdate(const char *p, const time_t *now)
  470. {
  471. time_t parsed = -1;
  472. int rc = parsedate(p, &parsed);
  473. (void)now; /* legacy argument from the past that we ignore */
  474. switch(rc) {
  475. case PARSEDATE_OK:
  476. case PARSEDATE_LATER:
  477. case PARSEDATE_SOONER:
  478. return parsed;
  479. }
  480. /* everything else is fail */
  481. return -1;
  482. }
  483. /*
  484. * Curl_gmtime() is a gmtime() replacement for portability. Do not use the
  485. * gmtime_r() or gmtime() functions anywhere else but here.
  486. *
  487. */
  488. CURLcode Curl_gmtime(time_t intime, struct tm *store)
  489. {
  490. const struct tm *tm;
  491. #ifdef HAVE_GMTIME_R
  492. /* thread-safe version */
  493. tm = (struct tm *)gmtime_r(&intime, store);
  494. #else
  495. tm = gmtime(&intime);
  496. if(tm)
  497. *store = *tm; /* copy the pointed struct to the local copy */
  498. #endif
  499. if(!tm)
  500. return CURLE_BAD_FUNCTION_ARGUMENT;
  501. return CURLE_OK;
  502. }