newlib/libc/time/tzset_r.c

   1 #include <_ansi.h>
   2 #include <reent.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #include <sys/types.h>
   7 #include <sys/time.h>
   8 #include "local.h"
   9
  10 #define sscanf siscanf  /* avoid to pull in FP functions. */
  11
  12 #define TZNAME_MIN      3       /* POSIX min TZ abbr size local def */
  13 #define TZNAME_MAX      10      /* POSIX max TZ abbr size local def */
  14
  15 static char __tzname_std[TZNAME_MAX + 2];
  16 static char __tzname_dst[TZNAME_MAX + 2];
  17 static char *prev_tzenv = NULL;
  18
  19 void
  20 _tzset_unlocked_r (struct _reent *reent_ptr)
  21 {
  22   char *tzenv;
  23   unsigned short hh, mm, ss, m, w, d;
  24   int sign, n;
  25   int i, ch;
  26   long offset0, offset1;
  27   __tzinfo_type *tz = __gettzinfo ();
  28   struct __tzrule_struct default_tzrule = {'J', 0, 0, 0, 0, (time_t)0, 0L };
  29
  30   if ((tzenv = _getenv_r (reent_ptr, "TZ")) == NULL)
  31       {
  32         _timezone = 0;
  33         _daylight = 0;
  34         _tzname[0] = "GMT";
  35         _tzname[1] = "GMT";
  36         tz->__tzrule[0] = default_tzrule;
  37         tz->__tzrule[1] = default_tzrule;
  38         free(prev_tzenv);
  39         prev_tzenv = NULL;
  40         return;
  41       }
  42
  43   if (prev_tzenv != NULL && strcmp(tzenv, prev_tzenv) == 0)
  44     return;
  45
  46   free(prev_tzenv);
  47   prev_tzenv = _malloc_r (reent_ptr, strlen(tzenv) + 1);
  48   if (prev_tzenv != NULL)
  49     strcpy (prev_tzenv, tzenv);
  50
  51   /* default to unnamed UTC in case of error */
  52   _timezone = 0;
  53   _daylight = 0;
  54   _tzname[0] = "";
  55   _tzname[1] = "";
  56   tz->__tzrule[0] = default_tzrule;
  57   tz->__tzrule[1] = default_tzrule;
  58
  59   /* ignore implementation-specific format specifier */
  60   if (*tzenv == ':')
  61     ++tzenv;
  62
  63   /* allow POSIX angle bracket < > quoted signed alphanumeric tz abbr e.g. <MESZ+0330> */
  64   if (*tzenv == '<')
  65     {
  66       ++tzenv;
  67
  68       /* quit if no items, too few or too many chars, or no close quote '>' */
  69       if (sscanf (tzenv, "%11[-+0-9A-Za-z]%n", __tzname_std, &n) <= 0
  70                 || n < TZNAME_MIN || TZNAME_MAX < n || '>' != tzenv[n])
  71         return;
  72
  73       ++tzenv;  /* bump for close quote '>' */
  74     }
  75   else
  76     {
  77       /* allow POSIX unquoted alphabetic tz abbr e.g. MESZ */
  78       if (sscanf (tzenv, "%11[A-Za-z]%n", __tzname_std, &n) <= 0
  79                                 || n < TZNAME_MIN || TZNAME_MAX < n)
  80         return;
  81     }
  82
  83   tzenv += n;
  84
  85   sign = 1;
  86   if (*tzenv == '-')
  87     {
  88       sign = -1;
  89       ++tzenv;
  90     }
  91   else if (*tzenv == '+')
  92     ++tzenv;
  93
  94   mm = 0;
  95   ss = 0;
  96
  97   if (sscanf (tzenv, "%hu%n:%hu%n:%hu%n", &hh, &n, &mm, &n, &ss, &n) < 1)
  98     return;
  99
 100   offset0 = sign * (ss + SECSPERMIN * mm + SECSPERHOUR * hh);
 101   tzenv += n;
 102
 103   /* allow POSIX angle bracket < > quoted signed alphanumeric tz abbr e.g. <MESZ+0330> */
 104   if (*tzenv == '<')
 105     {
 106       ++tzenv;
 107
 108       /* quit if no items, too few or too many chars, or no close quote '>' */
 109       if (sscanf (tzenv, "%11[-+0-9A-Za-z]%n", __tzname_dst, &n) <= 0 && tzenv[0] == '>')
 110         { /* No dst */
 111           _tzname[0] = __tzname_std;
 112           _tzname[1] = _tzname[0];
 113           tz->__tzrule[0].offset = offset0;
 114           _timezone = offset0;
 115           return;
 116         }
 117       else if (n < TZNAME_MIN || TZNAME_MAX < n || '>' != tzenv[n])
 118         { /* error */
 119           return;
 120         }
 121
 122       ++tzenv;  /* bump for close quote '>' */
 123     }
 124   else
 125     {
 126       /* allow POSIX unquoted alphabetic tz abbr e.g. MESZ */
 127       if (sscanf (tzenv, "%11[A-Za-z]%n", __tzname_dst, &n) <= 0)
 128         { /* No dst */
 129           _tzname[0] = __tzname_std;
 130           _tzname[1] = _tzname[0];
 131           tz->__tzrule[0].offset = offset0;
 132           _timezone = offset0;
 133           return;
 134         }
 135       else if (n < TZNAME_MIN || TZNAME_MAX < n)
 136         { /* error */
 137           return;
 138         }
 139     }
 140
 141   tzenv += n;
 142
 143   /* otherwise we have a dst name, look for the offset */
 144   sign = 1;
 145   if (*tzenv == '-')
 146     {
 147       sign = -1;
 148       ++tzenv;
 149     }
 150   else if (*tzenv == '+')
 151     ++tzenv;
 152
 153   hh = 0;
 154   mm = 0;
 155   ss = 0;
 156
 157   n  = 0;
 158   if (sscanf (tzenv, "%hu%n:%hu%n:%hu%n", &hh, &n, &mm, &n, &ss, &n) <= 0)
 159     offset1 = offset0 - 3600;
 160   else
 161     offset1 = sign * (ss + SECSPERMIN * mm + SECSPERHOUR * hh);
 162
 163   tzenv += n;
 164
 165   for (i = 0; i < 2; ++i)
 166     {
 167       if (*tzenv == ',')
 168         ++tzenv;
 169
 170       if (*tzenv == 'M')
 171         {
 172           if (sscanf (tzenv, "M%hu%n.%hu%n.%hu%n", &m, &n, &w, &n, &d, &n) != 3 ||
 173               m < 1 || m > 12 || w < 1 || w > 5 || d > 6)
 174             return;
 175
 176           tz->__tzrule[i].ch = 'M';
 177           tz->__tzrule[i].m = m;
 178           tz->__tzrule[i].n = w;
 179           tz->__tzrule[i].d = d;
 180
 181           tzenv += n;
 182         }
 183       else
 184         {
 185           char *end;
 186           if (*tzenv == 'J')
 187             {
 188               ch = 'J';
 189               ++tzenv;
 190             }
 191           else
 192             ch = 'D';
 193
 194           d = strtoul (tzenv, &end, 10);
 195
 196           /* if unspecified, default to US settings */
 197           /* From 1987-2006, US was M4.1.0,M10.5.0, but starting in 2007 is
 198            * M3.2.0,M11.1.0 (2nd Sunday March through 1st Sunday November)  */
 199           if (end == tzenv)
 200             {
 201               if (i == 0)
 202                 {
 203                   tz->__tzrule[0].ch = 'M';
 204                   tz->__tzrule[0].m = 3;
 205                   tz->__tzrule[0].n = 2;
 206                   tz->__tzrule[0].d = 0;
 207                 }
 208               else
 209                 {
 210                   tz->__tzrule[1].ch = 'M';
 211                   tz->__tzrule[1].m = 11;
 212                   tz->__tzrule[1].n = 1;
 213                   tz->__tzrule[1].d = 0;
 214                 }
 215             }
 216           else
 217             {
 218               tz->__tzrule[i].ch = ch;
 219               tz->__tzrule[i].d = d;
 220             }
 221
 222           tzenv = end;
 223         }
 224
 225       /* default time is 02:00:00 am */
 226       hh = 2;
 227       mm = 0;
 228       ss = 0;
 229       n = 0;
 230
 231       if (*tzenv == '/')
 232         if (sscanf (tzenv, "/%hu%n:%hu%n:%hu%n", &hh, &n, &mm, &n, &ss, &n) <= 0)
 233           {
 234             /* error in time format, restore tz rules to default and return */
 235             tz->__tzrule[0] = default_tzrule;
 236             tz->__tzrule[1] = default_tzrule;
 237             return;
 238           }
 239
 240       tz->__tzrule[i].s = ss + SECSPERMIN * mm + SECSPERHOUR  * hh;
 241
 242       tzenv += n;
 243     }
 244
 245   tz->__tzrule[0].offset = offset0;
 246   tz->__tzrule[1].offset = offset1;
 247   _tzname[0] = __tzname_std;
 248   _tzname[1] = __tzname_dst;
 249   __tzcalc_limits (tz->__tzyear);
 250   _timezone = tz->__tzrule[0].offset;
 251   _daylight = tz->__tzrule[0].offset != tz->__tzrule[1].offset;
 252 }
 253
 254 void
 255 _tzset_r (struct _reent *reent_ptr)
 256 {
 257   TZ_LOCK;
 258   _tzset_unlocked_r (reent_ptr);
 259   TZ_UNLOCK;
 260 }