1 /*
2  * Copyright (c) 2002-2018 Balabit
3  * Copyright (c) 1998-2018 Balázs Scheidler
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this library; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
18  *
19  * As an additional exemption you are allowed to compile & link against the
20  * OpenSSL libraries as published by the OpenSSL project. See the file
21  * COPYING for details.
22  *
23  */
24 /*  $NetBSD: strptime.c,v 1.49 2015/10/09 17:21:45 christos Exp $ */
25 
26 /*-
27  * Copyright (c) 1997, 1998, 2005, 2008 The NetBSD Foundation, Inc.
28  * All rights reserved.
29  *
30  * This code was contributed to The NetBSD Foundation by Klaus Klein.
31  * Heavily optimised by David Laight
32  *
33  * Redistribution and use in source and binary forms, with or without
34  * modification, are permitted provided that the following conditions
35  * are met:
36  * 1. Redistributions of source code must retain the above copyright
37  *    notice, this list of conditions and the following disclaimer.
38  * 2. Redistributions in binary form must reproduce the above copyright
39  *    notice, this list of conditions and the following disclaimer in the
40  *    documentation and/or other materials provided with the distribution.
41  *
42  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
43  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
44  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
45  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
46  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
47  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
48  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
49  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
50  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
51  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
52  * POSSIBILITY OF SUCH DAMAGE.
53  */
54 
55 /*
56  * MIT: musl http://git.musl-libc.org/cgit/musl/tree/src/time/strftime.c?id=6ad514e4e278f0c3b18eb2db1d45638c9af1c07f#n19
57  * The license below only applies for the ISO8601 week calculation in this file.
58  *
59  */
60 /*
61  *
62  *  Copyright © 2005-2019 Rich Felker, et al.
63  *
64  *  Permission is hereby granted, free of charge, to any person obtaining
65  *  a copy of this software and associated documentation files (the
66  *  "Software"), to deal in the Software without restriction, including
67  *  without limitation the rights to use, copy, modify, merge, publish,
68  *  distribute, sublicense, and/or sell copies of the Software, and to
69  *  permit persons to whom the Software is furnished to do so, subject to
70  *  the following conditions:
71  *
72  *  The above copyright notice and this permission notice shall be
73  *  included in all copies or substantial portions of the Software.
74  *
75  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
76  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
77  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
78  *  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
79  *  CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
80  *  TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
81  *  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
82  */
83 
84 #include <ctype.h>
85 #include <stdint.h>
86 #include <string.h>
87 
88 #include "timeutils/wallclocktime.h"
89 #include "timeutils/unixtime.h"
90 #include "timeutils/cache.h"
91 #include "timeutils/misc.h"
92 
93 void
wall_clock_time_unset(WallClockTime * self)94 wall_clock_time_unset(WallClockTime *self)
95 {
96   WallClockTime val = WALL_CLOCK_TIME_INIT;
97   *self = val;
98 }
99 
100 #define __UNCONST(a)    ((void *)(unsigned long)(const void *)(a))
101 
102 #define TM_YEAR_BASE 1900
103 #define TM_SUNDAY     0
104 #define TM_MONDAY     1
105 #define TM_TUESDAY    2
106 #define TM_WEDNESDAY  3
107 #define TM_THURSDAY   4
108 #define TM_FRIDAY     5
109 #define TM_SATURDAY   6
110 
111 #define TM_JANUARY   0
112 #define TM_FEBRUARY  1
113 #define TM_MARCH     2
114 #define TM_APRIL     3
115 #define TM_MAY       4
116 #define TM_JUNE      5
117 #define TM_JULY      6
118 #define TM_AUGUST    7
119 #define TM_SEPTEMBER 8
120 #define TM_OCTOBER   9
121 #define TM_NOVEMBER  10
122 #define TM_DECEMBER  11
123 
124 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
125 #define isleap_sum(a, b)  isleap((a) % 400 + (b) % 400)
126 
127 static gboolean
_is_jan1_3_days_past_monday(WallClockTime * wct)128 _is_jan1_3_days_past_monday(WallClockTime *wct)
129 {
130   return ((wct->wct_wday + 371 - wct->wct_yday - 2) % 7 <= 2);
131 }
132 
133 static gint
_get_dec31_day_of_week(WallClockTime * wct)134 _get_dec31_day_of_week(WallClockTime *wct)
135 {
136   return (wct->wct_wday + 7 - wct->wct_yday - 1) % 7;
137 }
138 
139 static gint
_get_jan1_day_of_week(WallClockTime * wct)140 _get_jan1_day_of_week(WallClockTime *wct)
141 {
142   return (wct->wct_wday + 371 - wct->wct_yday) % 7;
143 }
144 
145 guint32
wall_clock_time_iso_week_number(WallClockTime * wct)146 wall_clock_time_iso_week_number(WallClockTime *wct)
147 {
148   gint week_number = (wct->wct_yday - (wct->wct_wday - 1 + 7) % 7 + 7 ) / 7;
149 
150   if (_is_jan1_3_days_past_monday(wct))
151     week_number++;
152 
153   if (week_number == 0)
154     {
155       gint last_dec31 = _get_dec31_day_of_week(wct);
156       if (last_dec31 == 4 || (last_dec31 == 5 && isleap(wct->wct_year-1)))
157         return 53;
158       return 52;
159     }
160 
161   if (week_number == 53)
162     {
163       int jan1 = _get_jan1_day_of_week(wct);
164       if (jan1 != 4 && (jan1 != 3 || !isleap(wct->wct_year)))
165         return 1;
166     }
167 
168   return week_number;
169 }
170 
171 typedef struct
172 {
173   const char *abday[7];
174   const char *day[7];
175   const char *abmon[12];
176   const char *mon[12];
177   const char *am_pm[2];
178   const char *d_t_fmt;
179   const char *d_fmt;
180   const char *t_fmt;
181   const char *t_fmt_ampm;
182 } _TimeLocale;
183 
184 static const _TimeLocale _DefaultTimeLocale =
185 {
186   /* abbreviated day */
187   {
188     "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
189   },
190   /* days */
191   {
192     "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday",
193     "Friday", "Saturday"
194   },
195   /* abbreviated month */
196   {
197     "Jan", "Feb", "Mar", "Apr", "May", "Jun",
198     "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
199   },
200   /* month */
201   {
202     "January", "February", "March", "April", "May", "June", "July",
203     "August", "September", "October", "November", "December"
204   },
205   /* ampm */
206   {
207     "AM", "PM"
208   },
209   "%a %b %e %H:%M:%S %Y",
210   "%m/%d/%y",
211   "%H:%M:%S",
212   "%I:%M:%S %p"
213 };
214 
215 #define _TIME_LOCALE(loc) \
216   (&_DefaultTimeLocale)
217 
218 static const unsigned char *conv_num(const unsigned char *, int *, unsigned int, unsigned int);
219 static const unsigned char *find_string(const unsigned char *, int *, const char *const *,
220                                         const char *const *, int);
221 static int first_wday_of(int yr);
222 
223 
224 /*
225  * We do not implement alternate representations. However, we always
226  * check whether a given modifier is allowed for a certain conversion.
227  */
228 #define ALT_E     0x01
229 #define ALT_O     0x02
230 #define LEGAL_ALT(x)    { if (alt_format & ~(x)) return NULL; }
231 
232 #define S_YEAR      (1 << 0)
233 #define S_MON       (1 << 1)
234 #define S_YDAY      (1 << 2)
235 #define S_MDAY      (1 << 3)
236 #define S_WDAY      (1 << 4)
237 #define S_HOUR      (1 << 5)
238 #define S_USEC      (1 << 6)
239 
240 #define HAVE_MDAY(s)    (s & S_MDAY)
241 #define HAVE_MON(s)     (s & S_MON)
242 #define HAVE_WDAY(s)    (s & S_WDAY)
243 #define HAVE_YDAY(s)    (s & S_YDAY)
244 #define HAVE_YEAR(s)    (s & S_YEAR)
245 #define HAVE_HOUR(s)    (s & S_HOUR)
246 #define HAVE_USEC(s)    (s & S_USEC)
247 
248 static char utc[] = { "UTC" };
249 /* RFC-822/RFC-2822 */
250 static const char *const nast[5] =
251 {
252   "EST",    "CST",    "MST",    "PST",    "\0\0\0"
253 };
254 static const char *const nadt[5] =
255 {
256   "EDT",    "CDT",    "MDT",    "PDT",    "\0\0\0"
257 };
258 
259 /*
260  * Table to determine the ordinal date for the start of a month.
261  * Ref: http://en.wikipedia.org/wiki/ISO_week_date
262  */
263 static const int start_of_month[2][13] =
264 {
265   /* non-leap year */
266   { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
267   /* leap year */
268   { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
269 };
270 
271 gchar *
wall_clock_time_strptime(WallClockTime * wct,const gchar * format,const gchar * input)272 wall_clock_time_strptime(WallClockTime *wct, const gchar *format, const gchar *input)
273 {
274   unsigned char c;
275   const unsigned char *bp, *ep, *zname;
276   int alt_format, i, split_year = 0, neg = 0, state = 0,
277                      day_offset = -1, week_offset = 0, offs, mandatory;
278   const char *new_fmt;
279   const char *const *system_tznames;
280 
281   bp = (const unsigned char *)input;
282 
283   while (bp != NULL && (c = *format++) != '\0')
284     {
285       /* Clear `alternate' modifier prior to new conversion. */
286       alt_format = 0;
287       i = 0;
288 
289       /* Eat up white-space. */
290       if (isspace(c))
291         {
292           while (isspace(*bp))
293             bp++;
294           continue;
295         }
296 
297       if (c != '%')
298         goto literal;
299 
300 
301 again:
302       switch (c = *format++)
303         {
304         case '%': /* "%%" is converted to "%". */
305 literal:
306           if (c != *bp++)
307             return NULL;
308           LEGAL_ALT(0);
309           continue;
310 
311         /*
312          * "Alternative" modifiers. Just set the appropriate flag
313          * and start over again.
314          */
315         case 'E': /* "%E?" alternative conversion modifier. */
316           LEGAL_ALT(0);
317           alt_format |= ALT_E;
318           goto again;
319 
320         case 'O': /* "%O?" alternative conversion modifier. */
321           LEGAL_ALT(0);
322           alt_format |= ALT_O;
323           goto again;
324 
325         /*
326          * "Complex" conversion rules, implemented through recursion.
327          */
328         case 'c': /* Date and time, using the locale's format. */
329           new_fmt = _TIME_LOCALE(loc)->d_t_fmt;
330           state |= S_WDAY | S_MON | S_MDAY | S_YEAR;
331           goto recurse;
332 
333         case 'D': /* The date as "%m/%d/%y". */
334           new_fmt = "%m/%d/%y";
335           LEGAL_ALT(0);
336           state |= S_MON | S_MDAY | S_YEAR;
337           goto recurse;
338 
339         case 'F': /* The date as "%Y-%m-%d". */
340           new_fmt = "%Y-%m-%d";
341           LEGAL_ALT(0);
342           state |= S_MON | S_MDAY | S_YEAR;
343           goto recurse;
344 
345         case 'R': /* The time as "%H:%M". */
346           new_fmt = "%H:%M";
347           LEGAL_ALT(0);
348           goto recurse;
349 
350         case 'r': /* The time in 12-hour clock representation. */
351           new_fmt = _TIME_LOCALE(loc)->t_fmt_ampm;
352           LEGAL_ALT(0);
353           goto recurse;
354 
355         case 'T': /* The time as "%H:%M:%S". */
356           new_fmt = "%H:%M:%S";
357           LEGAL_ALT(0);
358           goto recurse;
359 
360         case 'X': /* The time, using the locale's format. */
361           new_fmt = _TIME_LOCALE(loc)->t_fmt;
362           goto recurse;
363 
364         case 'x': /* The date, using the locale's format. */
365           new_fmt = _TIME_LOCALE(loc)->d_fmt;
366           state |= S_MON | S_MDAY | S_YEAR;
367 recurse:
368           bp = (const unsigned char *)wall_clock_time_strptime(wct, new_fmt, (const char *)bp);
369           LEGAL_ALT(ALT_E);
370           continue;
371 
372         /*
373          * "Elementary" conversion rules.
374          */
375         case 'A': /* The day of week, using the locale's form. */
376         case 'a':
377           bp = find_string(bp, &wct->tm.tm_wday,
378                            _TIME_LOCALE(loc)->day, _TIME_LOCALE(loc)->abday, 7);
379           LEGAL_ALT(0);
380           state |= S_WDAY;
381           continue;
382 
383         case 'B': /* The month, using the locale's form. */
384         case 'b':
385         case 'h':
386           bp = find_string(bp, &wct->tm.tm_mon,
387                            _TIME_LOCALE(loc)->mon, _TIME_LOCALE(loc)->abmon,
388                            12);
389           LEGAL_ALT(0);
390           state |= S_MON;
391           continue;
392 
393         case 'C': /* The century number. */
394           i = 20;
395           bp = conv_num(bp, &i, 0, 99);
396 
397           i = i * 100 - TM_YEAR_BASE;
398           if (split_year)
399             i += wct->tm.tm_year % 100;
400           split_year = 1;
401           wct->tm.tm_year = i;
402           LEGAL_ALT(ALT_E);
403           state |= S_YEAR;
404           continue;
405 
406         case 'd': /* The day of month. */
407         case 'e':
408           bp = conv_num(bp, &wct->tm.tm_mday, 1, 31);
409           LEGAL_ALT(ALT_O);
410           state |= S_MDAY;
411           continue;
412 
413         case 'f':
414         {
415           const unsigned char *end = conv_num(bp, &wct->wct_usec, 0, 999999);
416           if (!end)
417             return NULL;
418           int digits = end - bp;
419 
420           /*
421            * We have read up to 6 digits, but if the message has
422            * sub-microsecond precision, eat-up the digits we cannot handle.
423            */
424           while (isdigit(*end))
425             {
426               end++;
427             }
428 
429           /*
430            * If we read less than 6 digits, we need to adjust the value:
431            * "012" was parsed as 12 but is 12000 us.
432            */
433           while (digits++ < 6)
434             {
435               wct->wct_usec *= 10;
436             }
437 
438           bp = end;
439           LEGAL_ALT(0);
440           state |= S_USEC;
441           continue;
442         }
443 
444         case 'k': /* The hour (24-hour clock representation). */
445           LEGAL_ALT(0);
446         /* FALLTHROUGH */
447         case 'H':
448           bp = conv_num(bp, &wct->tm.tm_hour, 0, 23);
449           LEGAL_ALT(ALT_O);
450           state |= S_HOUR;
451           continue;
452 
453         case 'l': /* The hour (12-hour clock representation). */
454           LEGAL_ALT(0);
455         /* FALLTHROUGH */
456         case 'I':
457           bp = conv_num(bp, &wct->tm.tm_hour, 1, 12);
458           if (wct->tm.tm_hour == 12)
459             wct->tm.tm_hour = 0;
460           LEGAL_ALT(ALT_O);
461           state |= S_HOUR;
462           continue;
463 
464         case 'j': /* The day of year. */
465           i = 1;
466           bp = conv_num(bp, &i, 1, 366);
467           wct->tm.tm_yday = i - 1;
468           LEGAL_ALT(0);
469           state |= S_YDAY;
470           continue;
471 
472         case 'M': /* The minute. */
473           bp = conv_num(bp, &wct->tm.tm_min, 0, 59);
474           LEGAL_ALT(ALT_O);
475           continue;
476 
477         case 'm': /* The month. */
478           i = 1;
479           bp = conv_num(bp, &i, 1, 12);
480           wct->tm.tm_mon = i - 1;
481           LEGAL_ALT(ALT_O);
482           state |= S_MON;
483           continue;
484 
485         case 'p': /* The locale's equivalent of AM/PM. */
486           bp = find_string(bp, &i, _TIME_LOCALE(loc)->am_pm,
487                            NULL, 2);
488           if (HAVE_HOUR(state) && wct->tm.tm_hour > 11)
489             return NULL;
490           wct->tm.tm_hour += i * 12;
491           LEGAL_ALT(0);
492           continue;
493 
494         case 'S': /* The seconds. */
495           bp = conv_num(bp, &wct->tm.tm_sec, 0, 61);
496           LEGAL_ALT(ALT_O);
497           continue;
498 
499 #ifndef TIME_MAX
500 #define TIME_MAX  INT64_MAX
501 #endif
502         case 's': /* seconds since the epoch */
503         {
504           time_t sse = 0;
505           uint64_t rulim = TIME_MAX;
506 
507           if (*bp < '0' || *bp > '9')
508             {
509               bp = NULL;
510               continue;
511             }
512 
513           do
514             {
515               sse *= 10;
516               sse += *bp++ - '0';
517               rulim /= 10;
518             }
519           while ((sse * 10 <= TIME_MAX) &&
520                  rulim && *bp >= '0' && *bp <= '9');
521 
522           if (sse < 0 || (uint64_t)sse > TIME_MAX)
523             {
524               bp = NULL;
525               continue;
526             }
527 
528           cached_localtime(&sse, &wct->tm);
529           state |= S_YDAY | S_WDAY |
530                    S_MON | S_MDAY | S_YEAR;
531         }
532         continue;
533 
534         case 'U': /* The week of year, beginning on sunday. */
535         case 'W': /* The week of year, beginning on monday. */
536           /*
537            * XXX This is bogus, as we can not assume any valid
538            * information present in the tm structure at this
539            * point to calculate a real value, so just check the
540            * range for now.
541            */
542           bp = conv_num(bp, &i, 0, 53);
543           LEGAL_ALT(ALT_O);
544           if (c == 'U')
545             day_offset = TM_SUNDAY;
546           else
547             day_offset = TM_MONDAY;
548           week_offset = i;
549           continue;
550 
551         case 'w': /* The day of week, beginning on sunday. */
552           bp = conv_num(bp, &wct->tm.tm_wday, 0, 6);
553           LEGAL_ALT(ALT_O);
554           state |= S_WDAY;
555           continue;
556 
557         case 'u': /* The day of week, monday = 1. */
558           bp = conv_num(bp, &i, 1, 7);
559           wct->tm.tm_wday = i % 7;
560           LEGAL_ALT(ALT_O);
561           state |= S_WDAY;
562           continue;
563 
564         case 'g': /* The year corresponding to the ISO week
565          * number but without the century.
566          */
567           bp = conv_num(bp, &i, 0, 99);
568           continue;
569 
570         case 'G': /* The year corresponding to the ISO week
571          * number with century.
572          */
573           do
574             bp++;
575           while (isdigit(*bp));
576           continue;
577 
578         case 'V': /* The ISO 8601:1988 week number as decimal */
579           bp = conv_num(bp, &i, 0, 53);
580           continue;
581 
582         case 'Y': /* The year. */
583           i = TM_YEAR_BASE; /* just for data sanity... */
584           bp = conv_num(bp, &i, 0, 9999);
585           wct->tm.tm_year = i - TM_YEAR_BASE;
586           LEGAL_ALT(ALT_E);
587           state |= S_YEAR;
588           continue;
589 
590         case 'y': /* The year within 100 years of the epoch. */
591           /* LEGAL_ALT(ALT_E | ALT_O); */
592           bp = conv_num(bp, &i, 0, 99);
593 
594           if (split_year)
595             /* preserve century */
596             i += (wct->tm.tm_year / 100) * 100;
597           else
598             {
599               split_year = 1;
600               if (i <= 68)
601                 i = i + 2000 - TM_YEAR_BASE;
602               else
603                 i = i + 1900 - TM_YEAR_BASE;
604             }
605           wct->tm.tm_year = i;
606           state |= S_YEAR;
607           continue;
608 
609         case 'Z':
610         case 'z':
611           mandatory = c == 'z';
612           /*
613            * We recognize all ISO 8601 formats:
614            * Z  = Zulu time/UTC
615            * [+-]hhmm
616            * [+-]hh:mm
617            * [+-]hh
618            * We recognize all RFC-822/RFC-2822 formats:
619            * UT|GMT
620            *          North American : UTC offsets
621            * E[DS]T = Eastern : -4 | -5
622            * C[DS]T = Central : -5 | -6
623            * M[DS]T = Mountain: -6 | -7
624            * P[DS]T = Pacific : -7 | -8
625            *          Military
626            * [A-IL-M] = -1 ... -9 (J not used)
627            * [N-Y]  = +1 ... +12
628            */
629           if (mandatory)
630             while (isspace(*bp))
631               bp++;
632 
633           zname = bp;
634           switch (*bp++)
635             {
636             case 'G':
637               if (*bp++ != 'M')
638                 return NULL;
639             /*FALLTHROUGH*/
640             case 'U':
641               if (*bp++ != 'T')
642                 return NULL;
643             /*FALLTHROUGH*/
644             case 'Z':
645               wct->tm.tm_isdst = 0;
646               wct->wct_gmtoff = 0;
647               wct->wct_zone = utc;
648               continue;
649             case '+':
650               neg = 0;
651               break;
652             case '-':
653               neg = 1;
654               break;
655             default:
656               --bp;
657               ep = find_string(bp, &i, nast, NULL, 4);
658               if (ep != NULL)
659                 {
660                   wct->wct_gmtoff = (-5 - i) * 3600;
661                   wct->wct_zone = __UNCONST(nast[i]);
662                   bp = ep;
663                   continue;
664                 }
665               ep = find_string(bp, &i, nadt, NULL, 4);
666               if (ep != NULL)
667                 {
668                   wct->tm.tm_isdst = 1;
669                   wct->wct_gmtoff = (-4 - i) * 3600;
670                   wct->wct_zone = __UNCONST(nadt[i]);
671                   bp = ep;
672                   continue;
673                 }
674               system_tznames = cached_get_system_tznames();
675               ep = find_string(bp, &i, system_tznames, NULL, 2);
676               if (ep != NULL)
677                 {
678                   wct->tm.tm_isdst = i;
679                   wct->wct_gmtoff = -cached_get_system_tzofs() + wct->tm.tm_isdst*3600;
680                   wct->wct_zone = system_tznames[i];
681                   bp = ep;
682                   continue;
683                 }
684 
685 
686               if ((*bp >= 'A' && *bp <= 'I') ||
687                   (*bp >= 'L' && *bp <= 'Y'))
688                 {
689                   /* Argh! No 'J'! */
690                   if (*bp >= 'A' && *bp <= 'I')
691                     wct->wct_gmtoff =
692                       (('A' - 1) - (int)*bp) * 3600;
693                   else if (*bp >= 'L' && *bp <= 'M')
694                     wct->wct_gmtoff = ('A' - (int)*bp) * 3600;
695                   else if (*bp >= 'N' && *bp <= 'Y')
696                     wct->wct_gmtoff = ((int)*bp - 'M') * 3600;
697                   wct->wct_zone = utc; /* XXX */
698                   bp++;
699                   continue;
700                 }
701               if (mandatory)
702                 return NULL;
703 
704               bp = zname;
705               continue;
706             }
707           offs = 0;
708           for (i = 0; i < 4; )
709             {
710               if (isdigit(*bp))
711                 {
712                   offs = offs * 10 + (*bp++ - '0');
713                   i++;
714                   continue;
715                 }
716               if (i == 2 && *bp == ':')
717                 {
718                   bp++;
719                   continue;
720                 }
721               break;
722             }
723           switch (i)
724             {
725             case 2:
726               offs *= 3600;
727               break;
728             case 4:
729               i = offs % 100;
730               offs /= 100;
731               if (i >= 60)
732                 goto out;
733               /* Convert minutes into decimal */
734               offs = offs * 3600 + i * 60;
735               break;
736             default:
737 out:
738               if (mandatory)
739                 return NULL;
740               bp = zname;
741               continue;
742             }
743           if (neg)
744             offs = -offs;
745           wct->tm.tm_isdst = 0; /* XXX */
746           wct->wct_gmtoff = offs;
747           wct->wct_zone = utc; /* XXX */
748           continue;
749 
750         /*
751          * Miscellaneous conversions.
752          */
753         case 'n': /* Any kind of white-space. */
754         case 't':
755           while (isspace(*bp))
756             bp++;
757           LEGAL_ALT(0);
758           continue;
759 
760 
761         default:  /* Unknown/unsupported conversion. */
762           return NULL;
763         }
764     }
765 
766   if (!HAVE_YDAY(state) && HAVE_YEAR(state))
767     {
768       if (HAVE_MON(state) && HAVE_MDAY(state))
769         {
770           /* calculate day of year (ordinal date) */
771           wct->tm.tm_yday =  start_of_month[isleap_sum(wct->tm.tm_year,
772                                                        TM_YEAR_BASE)][wct->tm.tm_mon] + (wct->tm.tm_mday - 1);
773           state |= S_YDAY;
774         }
775       else if (day_offset != -1)
776         {
777           /*
778            * Set the date to the first Sunday (or Monday)
779            * of the specified week of the year.
780            */
781           if (!HAVE_WDAY(state))
782             {
783               wct->tm.tm_wday = day_offset;
784               state |= S_WDAY;
785             }
786           wct->tm.tm_yday = (7 -
787                              first_wday_of(wct->tm.tm_year + TM_YEAR_BASE) +
788                              day_offset) % 7 + (week_offset - 1) * 7 +
789                             wct->tm.tm_wday  - day_offset;
790           state |= S_YDAY;
791         }
792     }
793 
794   if (HAVE_YDAY(state) && HAVE_YEAR(state))
795     {
796       int isleap;
797 
798       if (!HAVE_MON(state))
799         {
800           /* calculate month of day of year */
801           i = 0;
802           isleap = isleap_sum(wct->tm.tm_year, TM_YEAR_BASE);
803           while (wct->tm.tm_yday >= start_of_month[isleap][i])
804             i++;
805           if (i > 12)
806             {
807               i = 1;
808               wct->tm.tm_yday -= start_of_month[isleap][12];
809               wct->tm.tm_year++;
810             }
811           wct->tm.tm_mon = i - 1;
812           state |= S_MON;
813         }
814 
815       if (!HAVE_MDAY(state))
816         {
817           /* calculate day of month */
818           isleap = isleap_sum(wct->tm.tm_year, TM_YEAR_BASE);
819           wct->tm.tm_mday = wct->tm.tm_yday -
820                             start_of_month[isleap][wct->tm.tm_mon] + 1;
821           state |= S_MDAY;
822         }
823 
824       if (!HAVE_WDAY(state))
825         {
826           /* calculate day of week */
827           i = 0;
828           week_offset = first_wday_of(wct->tm.tm_year);
829           while (i++ <= wct->tm.tm_yday)
830             {
831               if (week_offset++ >= 6)
832                 week_offset = 0;
833             }
834           wct->tm.tm_wday = week_offset;
835           state |= S_WDAY;
836         }
837     }
838 
839   if (!HAVE_USEC(state))
840     {
841       wct->wct_usec = 0;
842     }
843 
844   return __UNCONST(bp);
845 }
846 
847 /* Determine (guess) the year for the month.
848  *
849  * It can be used for BSD logs, where year is missing.
850  */
851 static gint
determine_year_for_month(gint month,const struct tm * now)852 determine_year_for_month(gint month, const struct tm *now)
853 {
854   if (month == 11 && now->tm_mon == 0)
855     return now->tm_year - 1;
856   else if (month == 0 && now->tm_mon == 11)
857     return now->tm_year + 1;
858   else
859     return now->tm_year;
860 }
861 
862 void
wall_clock_time_guess_missing_year(WallClockTime * self)863 wall_clock_time_guess_missing_year(WallClockTime *self)
864 {
865   if (self->wct_year == -1)
866     {
867       time_t now;
868       struct tm tm;
869 
870       now = cached_g_current_time_sec();
871       cached_localtime(&now, &tm);
872       self->wct_year = determine_year_for_month(self->wct_mon, &tm);
873     }
874 }
875 
876 void
wall_clock_time_guess_missing_fields(WallClockTime * self)877 wall_clock_time_guess_missing_fields(WallClockTime *self)
878 {
879   /*
880    * The missing cases for date can be divided into three types:
881    * 1) missing all fileds -> use current date
882    * 2) only miss year -> guess year based on current year and month (current
883    * year, last year or next year)
884    * 3) the rest of the cases don't make much sense, so zero initialization of
885    * the missing field makes sense. And the year is initializeed to the current
886    *  one.
887    */
888   time_t now;
889   struct tm tm;
890 
891   now = cached_g_current_time_sec();
892   cached_localtime(&now, &tm);
893 
894   if (self->wct_year == -1 && self->wct_mon == -1 && self->wct_mday == -1)
895     {
896       self->wct_year = tm.tm_year;
897       self->wct_mon = tm.tm_mon;
898       self->wct_mday = tm.tm_mday;
899     }
900   else if (self->wct_year == -1 && self->wct_mon != -1 && self->wct_mday != -1)
901     {
902       self->wct_year = determine_year_for_month(self->wct_mon, &tm);
903     }
904   else
905     {
906       if (self->wct_year == -1)
907         self->wct_year = tm.tm_year;
908       if (self->wct_mon == -1)
909         self->wct_mon = 0;
910       if (self->wct_mday == -1)
911         self->wct_mday = 1;  // day of the month - [1, 31]
912     }
913 
914   if (self->wct_hour == -1)
915     self->wct_hour = 0;
916   if (self->wct_min == -1)
917     self->wct_min = 0;
918   if (self->wct_sec == -1)
919     self->wct_sec = 0;
920 }
921 
922 
923 /*
924  * Calculate the week day of the first day of a year. Valid for
925  * the Gregorian calendar, which began Sept 14, 1752 in the UK
926  * and its colonies. Ref:
927  * http://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week
928  */
929 
930 static int
first_wday_of(int yr)931 first_wday_of(int yr)
932 {
933   return ((2 * (3 - (yr / 100) % 4)) + (yr % 100) + ((yr % 100) /  4) +
934           (isleap(yr) ? 6 : 0) + 1) % 7;
935 }
936 
937 
938 static const unsigned char *
conv_num(const unsigned char * input,int * dest,unsigned int llim,unsigned int ulim)939 conv_num(const unsigned char *input, int *dest, unsigned int llim, unsigned int ulim)
940 {
941   unsigned int result = 0;
942   unsigned char ch;
943 
944   /* The limit also determines the number of valid digits. */
945   unsigned int rulim = ulim;
946 
947   ch = *input;
948   if (ch < '0' || ch > '9')
949     return NULL;
950 
951   do
952     {
953       result *= 10;
954       result += ch - '0';
955       rulim /= 10;
956       ch = *++input;
957     }
958   while ((result * 10 <= ulim) && rulim && ch >= '0' && ch <= '9');
959 
960   if (result < llim || result > ulim)
961     return NULL;
962 
963   *dest = result;
964   return input;
965 }
966 
967 static const unsigned char *
find_string(const unsigned char * bp,int * tgt,const char * const * n1,const char * const * n2,int c)968 find_string(const unsigned char *bp, int *tgt, const char *const *n1,
969             const char *const *n2, int c)
970 {
971   int i;
972   size_t len;
973 
974   /* check full name - then abbreviated ones */
975   for (; n1 != NULL; n1 = n2, n2 = NULL)
976     {
977       for (i = 0; i < c; i++, n1++)
978         {
979           len = strlen(*n1);
980           if (strncasecmp(*n1, (const char *)bp, len) == 0)
981             {
982               *tgt = i;
983               return bp + len;
984             }
985         }
986     }
987 
988   /* Nothing matched */
989   return NULL;
990 }
991