common/gettime.c

   1 /* gettime.c - Wrapper for time functions
   2  *      Copyright (C) 1998, 2002 Free Software Foundation, Inc.
   3  *
   4  * This file is part of GnuPG.
   5  *
   6  * GnuPG is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GnuPG is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  19  */
  20
  21 #include <config.h>
  22 #include <stdlib.h>
  23 #include <time.h>
  24 #ifdef HAVE_LANGINFO_H
  25 #include <langinfo.h>
  26 #endif
  27
  28 #include "util.h"
  29
  30 static unsigned long timewarp;
  31 static enum { NORMAL = 0, FROZEN, FUTURE, PAST } timemode;
  32
  33 /* Wrapper for the time(3).  We use this here so we can fake the time
  34    for tests */
  35 time_t
  36 gnupg_get_time ()
  37 {
  38   time_t current = time (NULL);
  39   if (timemode == NORMAL)
  40     return current;
  41   else if (timemode == FROZEN)
  42     return timewarp;
  43   else if (timemode == FUTURE)
  44     return current + timewarp;
  45   else
  46     return current - timewarp;
  47 }
  48
  49
  50 /* Return the current time (possibly faked) in ISO format. */
  51 void
  52 gnupg_get_isotime (gnupg_isotime_t timebuf)
  53 {
  54   time_t atime = gnupg_get_time ();
  55
  56   if (atime < 0)
  57     *timebuf = 0;
  58   else
  59     {
  60       struct tm *tp;
  61 #ifdef HAVE_GMTIME_R
  62       struct tm tmbuf;
  63
  64       tp = gmtime_r (&atime, &tmbuf);
  65 #else
  66       tp = gmtime (&atime);
  67 #endif
  68       sprintf (timebuf,"%04d%02d%02dT%02d%02d%02d",
  69                1900 + tp->tm_year, tp->tm_mon+1, tp->tm_mday,
  70                tp->tm_hour, tp->tm_min, tp->tm_sec);
  71     }
  72 }
  73
  74
  75 /* set the time to NEWTIME so that gnupg_get_time returns a time
  76    starting with this one.  With FREEZE set to 1 the returned time
  77    will never change.  Just for completeness, a value of (time_t)-1
  78    for NEWTIME gets you back to rality. Note that this is obviously
  79    not thread-safe but this is not required. */
  80 void
  81 gnupg_set_time (time_t newtime, int freeze)
  82 {
  83   time_t current = time (NULL);
  84
  85   if ( newtime == (time_t)-1 || current == newtime)
  86     {
  87       timemode = NORMAL;
  88       timewarp = 0;
  89     }
  90   else if (freeze)
  91     {
  92       timemode = FROZEN;
  93       timewarp = current;
  94     }
  95   else if (newtime > current)
  96     {
  97       timemode = FUTURE;
  98       timewarp = newtime - current;
  99     }
 100   else
 101     {
 102       timemode = PAST;
 103       timewarp = current - newtime;
 104     }
 105 }
 106
 107 /* Returns true when we are in timewarp mode */
 108 int
 109 gnupg_faked_time_p (void)
 110 {
 111   return timemode;
 112 }
 113
 114
 115 /* This function is used by gpg because OpenPGP defines the timestamp
 116    as an unsigned 32 bit value. */
 117 u32
 118 make_timestamp (void)
 119 {
 120   time_t t = gnupg_get_time ();
 121
 122   if (t == (time_t)-1)
 123     log_fatal ("gnupg_get_time() failed\n");
 124   return (u32)t;
 125 }
 126
 127
 128
 129 /****************
 130  * Scan a date string and return a timestamp.
 131  * The only supported format is "yyyy-mm-dd"
 132  * Returns 0 for an invalid date.
 133  */
 134 u32
 135 scan_isodatestr( const char *string )
 136 {
 137     int year, month, day;
 138     struct tm tmbuf;
 139     time_t stamp;
 140     int i;
 141
 142     if( strlen(string) != 10 || string[4] != '-' || string[7] != '-' )
 143         return 0;
 144     for( i=0; i < 4; i++ )
 145         if( !digitp (string+i) )
 146             return 0;
 147     if( !digitp (string+5) || !digitp(string+6) )
 148         return 0;
 149     if( !digitp(string+8) || !digitp(string+9) )
 150         return 0;
 151     year = atoi(string);
 152     month = atoi(string+5);
 153     day = atoi(string+8);
 154     /* some basic checks */
 155     if( year < 1970 || month < 1 || month > 12 || day < 1 || day > 31 )
 156         return 0;
 157     memset( &tmbuf, 0, sizeof tmbuf );
 158     tmbuf.tm_mday = day;
 159     tmbuf.tm_mon = month-1;
 160     tmbuf.tm_year = year - 1900;
 161     tmbuf.tm_isdst = -1;
 162     stamp = mktime( &tmbuf );
 163     if( stamp == (time_t)-1 )
 164         return 0;
 165     return stamp;
 166 }
 167
 168
 169 u32
 170 add_days_to_timestamp( u32 stamp, u16 days )
 171 {
 172     return stamp + days*86400L;
 173 }
 174
 175
 176 /****************
 177  * Return a string with a time value in the form: x Y, n D, n H
 178  */
 179
 180 const char *
 181 strtimevalue( u32 value )
 182 {
 183     static char buffer[30];
 184     unsigned int years, days, hours, minutes;
 185
 186     value /= 60;
 187     minutes = value % 60;
 188     value /= 60;
 189     hours = value % 24;
 190     value /= 24;
 191     days = value % 365;
 192     value /= 365;
 193     years = value;
 194
 195     sprintf(buffer,"%uy%ud%uh%um", years, days, hours, minutes );
 196     if( years )
 197         return buffer;
 198     if( days )
 199         return strchr( buffer, 'y' ) + 1;
 200     return strchr( buffer, 'd' ) + 1;
 201 }
 202
 203
 204 /****************
 205  * Note: this function returns GMT
 206  */
 207 const char *
 208 strtimestamp( u32 stamp )
 209 {
 210     static char buffer[11+5];
 211     struct tm *tp;
 212     time_t atime = stamp;
 213
 214     if (atime < 0) {
 215         strcpy (buffer, "????" "-??" "-??");
 216     }
 217     else {
 218         tp = gmtime( &atime );
 219         sprintf(buffer,"%04d-%02d-%02d",
 220                 1900+tp->tm_year, tp->tm_mon+1, tp->tm_mday );
 221     }
 222     return buffer;
 223 }
 224
 225 /****************
 226  * Note: this function returns local time
 227  */
 228 const char *
 229 asctimestamp( u32 stamp )
 230 {
 231     static char buffer[50];
 232 #if defined (HAVE_STRFTIME) && defined (HAVE_NL_LANGINFO)
 233       static char fmt[50];
 234 #endif
 235     struct tm *tp;
 236     time_t atime = stamp;
 237
 238     if (atime < 0) {
 239         strcpy (buffer, "????" "-??" "-??");
 240         return buffer;
 241     }
 242
 243     tp = localtime( &atime );
 244 #ifdef HAVE_STRFTIME
 245 #if defined(HAVE_NL_LANGINFO)
 246       mem2str( fmt, nl_langinfo(D_T_FMT), DIM(fmt)-3 );
 247       if( strstr( fmt, "%Z" ) == NULL )
 248         strcat( fmt, " %Z");
 249       /* NOTE: gcc -Wformat-noliteral will complain here.  I have
 250          found no way to suppress this warning .*/
 251       strftime (buffer, DIM(buffer)-1, fmt, tp);
 252 #else
 253       /* FIXME: we should check whether the locale appends a " %Z"
 254        * These locales from glibc don't put the " %Z":
 255        * fi_FI hr_HR ja_JP lt_LT lv_LV POSIX ru_RU ru_SU sv_FI sv_SE zh_CN
 256        */
 257       strftime( buffer, DIM(buffer)-1, "%c %Z", tp );
 258 #endif
 259     buffer[DIM(buffer)-1] = 0;
 260 #else
 261     mem2str( buffer, asctime(tp), DIM(buffer) );
 262 #endif
 263     return buffer;
 264 }
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