src/basic/time-util.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <limits.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/stat.h>
  25 #include <sys/time.h>
  26 #include <sys/timerfd.h>
  27 #include <sys/timex.h>
  28 #include <sys/types.h>
  29 #include <unistd.h>
  30
  31 #include "alloc-util.h"
  32 #include "fd-util.h"
  33 #include "fileio.h"
  34 #include "fs-util.h"
  35 #include "log.h"
  36 #include "macro.h"
  37 #include "parse-util.h"
  38 #include "path-util.h"
  39 #include "string-util.h"
  40 #include "strv.h"
  41 #include "time-util.h"
  42
  43 static clockid_t map_clock_id(clockid_t c) {
  44
  45         /* Some more exotic archs (s390, ppc, …) lack the "ALARM" flavour of the clocks. Thus, clock_gettime() will
  46          * fail for them. Since they are essentially the same as their non-ALARM pendants (their only difference is
  47          * when timers are set on them), let's just map them accordingly. This way, we can get the correct time even on
  48          * those archs. */
  49
  50         switch (c) {
  51
  52         case CLOCK_BOOTTIME_ALARM:
  53                 return CLOCK_BOOTTIME;
  54
  55         case CLOCK_REALTIME_ALARM:
  56                 return CLOCK_REALTIME;
  57
  58         default:
  59                 return c;
  60         }
  61 }
  62
  63 usec_t now(clockid_t clock_id) {
  64         struct timespec ts;
  65
  66         assert_se(clock_gettime(map_clock_id(clock_id), &ts) == 0);
  67
  68         return timespec_load(&ts);
  69 }
  70
  71 #if 0 /// UNNEEDED by elogind
  72 nsec_t now_nsec(clockid_t clock_id) {
  73         struct timespec ts;
  74
  75         assert_se(clock_gettime(map_clock_id(clock_id), &ts) == 0);
  76
  77         return timespec_load_nsec(&ts);
  78 }
  79 #endif // 0
  80
  81 dual_timestamp* dual_timestamp_get(dual_timestamp *ts) {
  82         assert(ts);
  83
  84         ts->realtime = now(CLOCK_REALTIME);
  85         ts->monotonic = now(CLOCK_MONOTONIC);
  86
  87         return ts;
  88 }
  89
  90 triple_timestamp* triple_timestamp_get(triple_timestamp *ts) {
  91         assert(ts);
  92
  93         ts->realtime = now(CLOCK_REALTIME);
  94         ts->monotonic = now(CLOCK_MONOTONIC);
  95         ts->boottime = clock_boottime_supported() ? now(CLOCK_BOOTTIME) : USEC_INFINITY;
  96
  97         return ts;
  98 }
  99
 100 dual_timestamp* dual_timestamp_from_realtime(dual_timestamp *ts, usec_t u) {
 101         int64_t delta;
 102         assert(ts);
 103
 104         if (u == USEC_INFINITY || u <= 0) {
 105                 ts->realtime = ts->monotonic = u;
 106                 return ts;
 107         }
 108
 109         ts->realtime = u;
 110
 111         delta = (int64_t) now(CLOCK_REALTIME) - (int64_t) u;
 112         ts->monotonic = usec_sub_signed(now(CLOCK_MONOTONIC), delta);
 113
 114         return ts;
 115 }
 116
 117 #if 0 /// UNNEEDED by elogind
 118 triple_timestamp* triple_timestamp_from_realtime(triple_timestamp *ts, usec_t u) {
 119         int64_t delta;
 120
 121         assert(ts);
 122
 123         if (u == USEC_INFINITY || u <= 0) {
 124                 ts->realtime = ts->monotonic = ts->boottime = u;
 125                 return ts;
 126         }
 127
 128         ts->realtime = u;
 129         delta = (int64_t) now(CLOCK_REALTIME) - (int64_t) u;
 130         ts->monotonic = usec_sub_signed(now(CLOCK_MONOTONIC), delta);
 131         ts->boottime = clock_boottime_supported() ? usec_sub_signed(now(CLOCK_BOOTTIME), delta) : USEC_INFINITY;
 132
 133         return ts;
 134 }
 135
 136 dual_timestamp* dual_timestamp_from_monotonic(dual_timestamp *ts, usec_t u) {
 137         int64_t delta;
 138         assert(ts);
 139
 140         if (u == USEC_INFINITY) {
 141                 ts->realtime = ts->monotonic = USEC_INFINITY;
 142                 return ts;
 143         }
 144
 145         ts->monotonic = u;
 146         delta = (int64_t) now(CLOCK_MONOTONIC) - (int64_t) u;
 147         ts->realtime = usec_sub_signed(now(CLOCK_REALTIME), delta);
 148
 149         return ts;
 150 }
 151
 152 dual_timestamp* dual_timestamp_from_boottime_or_monotonic(dual_timestamp *ts, usec_t u) {
 153         int64_t delta;
 154
 155         if (u == USEC_INFINITY) {
 156                 ts->realtime = ts->monotonic = USEC_INFINITY;
 157                 return ts;
 158         }
 159
 160         dual_timestamp_get(ts);
 161         delta = (int64_t) now(clock_boottime_or_monotonic()) - (int64_t) u;
 162         ts->realtime = usec_sub_signed(ts->realtime, delta);
 163         ts->monotonic = usec_sub_signed(ts->monotonic, delta);
 164
 165         return ts;
 166 }
 167 #endif // 0
 168
 169 usec_t triple_timestamp_by_clock(triple_timestamp *ts, clockid_t clock) {
 170
 171         switch (clock) {
 172
 173         case CLOCK_REALTIME:
 174         case CLOCK_REALTIME_ALARM:
 175                 return ts->realtime;
 176
 177         case CLOCK_MONOTONIC:
 178                 return ts->monotonic;
 179
 180         case CLOCK_BOOTTIME:
 181         case CLOCK_BOOTTIME_ALARM:
 182                 return ts->boottime;
 183
 184         default:
 185                 return USEC_INFINITY;
 186         }
 187 }
 188
 189 usec_t timespec_load(const struct timespec *ts) {
 190         assert(ts);
 191
 192         if (ts->tv_sec < 0 || ts->tv_nsec < 0)
 193                 return USEC_INFINITY;
 194
 195         if ((usec_t) ts->tv_sec > (UINT64_MAX - (ts->tv_nsec / NSEC_PER_USEC)) / USEC_PER_SEC)
 196                 return USEC_INFINITY;
 197
 198         return
 199                 (usec_t) ts->tv_sec * USEC_PER_SEC +
 200                 (usec_t) ts->tv_nsec / NSEC_PER_USEC;
 201 }
 202
 203 #if 0 /// UNNEEDED by elogind
 204 nsec_t timespec_load_nsec(const struct timespec *ts) {
 205         assert(ts);
 206
 207         if (ts->tv_sec < 0 || ts->tv_nsec < 0)
 208                 return NSEC_INFINITY;
 209
 210         if ((nsec_t) ts->tv_sec >= (UINT64_MAX - ts->tv_nsec) / NSEC_PER_SEC)
 211                 return NSEC_INFINITY;
 212
 213         return (nsec_t) ts->tv_sec * NSEC_PER_SEC + (nsec_t) ts->tv_nsec;
 214 }
 215 #endif // 0
 216
 217 struct timespec *timespec_store(struct timespec *ts, usec_t u)  {
 218         assert(ts);
 219
 220         if (u == USEC_INFINITY ||
 221             u / USEC_PER_SEC >= TIME_T_MAX) {
 222                 ts->tv_sec = (time_t) -1;
 223                 ts->tv_nsec = (long) -1;
 224                 return ts;
 225         }
 226
 227         ts->tv_sec = (time_t) (u / USEC_PER_SEC);
 228         ts->tv_nsec = (long int) ((u % USEC_PER_SEC) * NSEC_PER_USEC);
 229
 230         return ts;
 231 }
 232
 233 usec_t timeval_load(const struct timeval *tv) {
 234         assert(tv);
 235
 236         if (tv->tv_sec < 0 || tv->tv_usec < 0)
 237                 return USEC_INFINITY;
 238
 239         if ((usec_t) tv->tv_sec > (UINT64_MAX - tv->tv_usec) / USEC_PER_SEC)
 240                 return USEC_INFINITY;
 241
 242         return
 243                 (usec_t) tv->tv_sec * USEC_PER_SEC +
 244                 (usec_t) tv->tv_usec;
 245 }
 246
 247 struct timeval *timeval_store(struct timeval *tv, usec_t u) {
 248         assert(tv);
 249
 250         if (u == USEC_INFINITY ||
 251             u / USEC_PER_SEC > TIME_T_MAX) {
 252                 tv->tv_sec = (time_t) -1;
 253                 tv->tv_usec = (suseconds_t) -1;
 254         } else {
 255                 tv->tv_sec = (time_t) (u / USEC_PER_SEC);
 256                 tv->tv_usec = (suseconds_t) (u % USEC_PER_SEC);
 257         }
 258
 259         return tv;
 260 }
 261
 262 static char *format_timestamp_internal(
 263                 char *buf,
 264                 size_t l,
 265                 usec_t t,
 266                 bool utc,
 267                 bool us) {
 268
 269         /* The weekdays in non-localized (English) form. We use this instead of the localized form, so that our
 270          * generated timestamps may be parsed with parse_timestamp(), and always read the same. */
 271         static const char * const weekdays[] = {
 272                 [0] = "Sun",
 273                 [1] = "Mon",
 274                 [2] = "Tue",
 275                 [3] = "Wed",
 276                 [4] = "Thu",
 277                 [5] = "Fri",
 278                 [6] = "Sat",
 279         };
 280
 281         struct tm tm;
 282         time_t sec;
 283         size_t n;
 284
 285         assert(buf);
 286
 287         if (l <
 288             3 +                  /* week day */
 289             1 + 10 +             /* space and date */
 290             1 + 8 +              /* space and time */
 291             (us ? 1 + 6 : 0) +   /* "." and microsecond part */
 292             1 + 1 +              /* space and shortest possible zone */
 293             1)
 294                 return NULL; /* Not enough space even for the shortest form. */
 295         if (t <= 0 || t == USEC_INFINITY)
 296                 return NULL; /* Timestamp is unset */
 297
 298         /* Let's not format times with years > 9999 */
 299         if (t > USEC_TIMESTAMP_FORMATTABLE_MAX)
 300                 return NULL;
 301
 302         sec = (time_t) (t / USEC_PER_SEC); /* Round down */
 303
 304         if (!localtime_or_gmtime_r(&sec, &tm, utc))
 305                 return NULL;
 306
 307         /* Start with the week day */
 308         assert((size_t) tm.tm_wday < ELEMENTSOF(weekdays));
 309         memcpy(buf, weekdays[tm.tm_wday], 4);
 310
 311         /* Add the main components */
 312         if (strftime(buf + 3, l - 3, " %Y-%m-%d %H:%M:%S", &tm) <= 0)
 313                 return NULL; /* Doesn't fit */
 314
 315         /* Append the microseconds part, if that's requested */
 316         if (us) {
 317                 n = strlen(buf);
 318                 if (n + 8 > l)
 319                         return NULL; /* Microseconds part doesn't fit. */
 320
 321                 sprintf(buf + n, ".%06"PRI_USEC, t % USEC_PER_SEC);
 322         }
 323
 324         /* Append the timezone */
 325         n = strlen(buf);
 326         if (utc) {
 327                 /* If this is UTC then let's explicitly use the "UTC" string here, because gmtime_r() normally uses the
 328                  * obsolete "GMT" instead. */
 329                 if (n + 5 > l)
 330                         return NULL; /* "UTC" doesn't fit. */
 331
 332                 strcpy(buf + n, " UTC");
 333
 334         } else if (!isempty(tm.tm_zone)) {
 335                 size_t tn;
 336
 337                 /* An explicit timezone is specified, let's use it, if it fits */
 338                 tn = strlen(tm.tm_zone);
 339                 if (n + 1 + tn + 1 > l) {
 340                         /* The full time zone does not fit in. Yuck. */
 341
 342                         if (n + 1 + _POSIX_TZNAME_MAX + 1 > l)
 343                                 return NULL; /* Not even enough space for the POSIX minimum (of 6)? In that case, complain that it doesn't fit */
 344
 345                         /* So the time zone doesn't fit in fully, but the caller passed enough space for the POSIX
 346                          * minimum time zone length. In this case suppress the timezone entirely, in order not to dump
 347                          * an overly long, hard to read string on the user. This should be safe, because the user will
 348                          * assume the local timezone anyway if none is shown. And so does parse_timestamp(). */
 349                 } else {
 350                         buf[n++] = ' ';
 351                         strcpy(buf + n, tm.tm_zone);
 352                 }
 353         }
 354
 355         return buf;
 356 }
 357
 358 char *format_timestamp(char *buf, size_t l, usec_t t) {
 359         return format_timestamp_internal(buf, l, t, false, false);
 360 }
 361
 362 #if 0 /// UNNEEDED by elogind
 363 char *format_timestamp_utc(char *buf, size_t l, usec_t t) {
 364         return format_timestamp_internal(buf, l, t, true, false);
 365 }
 366 #endif // 0
 367
 368 char *format_timestamp_us(char *buf, size_t l, usec_t t) {
 369         return format_timestamp_internal(buf, l, t, false, true);
 370 }
 371
 372 #if 0 /// UNNEEDED by elogind
 373 char *format_timestamp_us_utc(char *buf, size_t l, usec_t t) {
 374         return format_timestamp_internal(buf, l, t, true, true);
 375 }
 376 #endif // 0
 377
 378 char *format_timestamp_relative(char *buf, size_t l, usec_t t) {
 379         const char *s;
 380         usec_t n, d;
 381
 382         if (t <= 0 || t == USEC_INFINITY)
 383                 return NULL;
 384
 385         n = now(CLOCK_REALTIME);
 386         if (n > t) {
 387                 d = n - t;
 388                 s = "ago";
 389         } else {
 390                 d = t - n;
 391                 s = "left";
 392         }
 393
 394         if (d >= USEC_PER_YEAR)
 395                 snprintf(buf, l, USEC_FMT " years " USEC_FMT " months %s",
 396                          d / USEC_PER_YEAR,
 397                          (d % USEC_PER_YEAR) / USEC_PER_MONTH, s);
 398         else if (d >= USEC_PER_MONTH)
 399                 snprintf(buf, l, USEC_FMT " months " USEC_FMT " days %s",
 400                          d / USEC_PER_MONTH,
 401                          (d % USEC_PER_MONTH) / USEC_PER_DAY, s);
 402         else if (d >= USEC_PER_WEEK)
 403                 snprintf(buf, l, USEC_FMT " weeks " USEC_FMT " days %s",
 404                          d / USEC_PER_WEEK,
 405                          (d % USEC_PER_WEEK) / USEC_PER_DAY, s);
 406         else if (d >= 2*USEC_PER_DAY)
 407                 snprintf(buf, l, USEC_FMT " days %s", d / USEC_PER_DAY, s);
 408         else if (d >= 25*USEC_PER_HOUR)
 409                 snprintf(buf, l, "1 day " USEC_FMT "h %s",
 410                          (d - USEC_PER_DAY) / USEC_PER_HOUR, s);
 411         else if (d >= 6*USEC_PER_HOUR)
 412                 snprintf(buf, l, USEC_FMT "h %s",
 413                          d / USEC_PER_HOUR, s);
 414         else if (d >= USEC_PER_HOUR)
 415                 snprintf(buf, l, USEC_FMT "h " USEC_FMT "min %s",
 416                          d / USEC_PER_HOUR,
 417                          (d % USEC_PER_HOUR) / USEC_PER_MINUTE, s);
 418         else if (d >= 5*USEC_PER_MINUTE)
 419                 snprintf(buf, l, USEC_FMT "min %s",
 420                          d / USEC_PER_MINUTE, s);
 421         else if (d >= USEC_PER_MINUTE)
 422                 snprintf(buf, l, USEC_FMT "min " USEC_FMT "s %s",
 423                          d / USEC_PER_MINUTE,
 424                          (d % USEC_PER_MINUTE) / USEC_PER_SEC, s);
 425         else if (d >= USEC_PER_SEC)
 426                 snprintf(buf, l, USEC_FMT "s %s",
 427                          d / USEC_PER_SEC, s);
 428         else if (d >= USEC_PER_MSEC)
 429                 snprintf(buf, l, USEC_FMT "ms %s",
 430                          d / USEC_PER_MSEC, s);
 431         else if (d > 0)
 432                 snprintf(buf, l, USEC_FMT"us %s",
 433                          d, s);
 434         else
 435                 snprintf(buf, l, "now");
 436
 437         buf[l-1] = 0;
 438         return buf;
 439 }
 440
 441 char *format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy) {
 442         static const struct {
 443                 const char *suffix;
 444                 usec_t usec;
 445         } table[] = {
 446                 { "y",     USEC_PER_YEAR   },
 447                 { "month", USEC_PER_MONTH  },
 448                 { "w",     USEC_PER_WEEK   },
 449                 { "d",     USEC_PER_DAY    },
 450                 { "h",     USEC_PER_HOUR   },
 451                 { "min",   USEC_PER_MINUTE },
 452                 { "s",     USEC_PER_SEC    },
 453                 { "ms",    USEC_PER_MSEC   },
 454                 { "us",    1               },
 455         };
 456
 457         unsigned i;
 458         char *p = buf;
 459         bool something = false;
 460
 461         assert(buf);
 462         assert(l > 0);
 463
 464         if (t == USEC_INFINITY) {
 465                 strncpy(p, "infinity", l-1);
 466                 p[l-1] = 0;
 467                 return p;
 468         }
 469
 470         if (t <= 0) {
 471                 strncpy(p, "0", l-1);
 472                 p[l-1] = 0;
 473                 return p;
 474         }
 475
 476         /* The result of this function can be parsed with parse_sec */
 477
 478         for (i = 0; i < ELEMENTSOF(table); i++) {
 479                 int k = 0;
 480                 size_t n;
 481                 bool done = false;
 482                 usec_t a, b;
 483
 484                 if (t <= 0)
 485                         break;
 486
 487                 if (t < accuracy && something)
 488                         break;
 489
 490                 if (t < table[i].usec)
 491                         continue;
 492
 493                 if (l <= 1)
 494                         break;
 495
 496                 a = t / table[i].usec;
 497                 b = t % table[i].usec;
 498
 499                 /* Let's see if we should shows this in dot notation */
 500                 if (t < USEC_PER_MINUTE && b > 0) {
 501                         usec_t cc;
 502                         int j;
 503
 504                         j = 0;
 505                         for (cc = table[i].usec; cc > 1; cc /= 10)
 506                                 j++;
 507
 508                         for (cc = accuracy; cc > 1; cc /= 10) {
 509                                 b /= 10;
 510                                 j--;
 511                         }
 512
 513                         if (j > 0) {
 514                                 k = snprintf(p, l,
 515                                              "%s"USEC_FMT".%0*"PRI_USEC"%s",
 516                                              p > buf ? " " : "",
 517                                              a,
 518                                              j,
 519                                              b,
 520                                              table[i].suffix);
 521
 522                                 t = 0;
 523                                 done = true;
 524                         }
 525                 }
 526
 527                 /* No? Then let's show it normally */
 528                 if (!done) {
 529                         k = snprintf(p, l,
 530                                      "%s"USEC_FMT"%s",
 531                                      p > buf ? " " : "",
 532                                      a,
 533                                      table[i].suffix);
 534
 535                         t = b;
 536                 }
 537
 538                 n = MIN((size_t) k, l);
 539
 540                 l -= n;
 541                 p += n;
 542
 543                 something = true;
 544         }
 545
 546         *p = 0;
 547
 548         return buf;
 549 }
 550
 551 #if 0 /// UNNEEDED by elogind
 552 void dual_timestamp_serialize(FILE *f, const char *name, dual_timestamp *t) {
 553
 554         assert(f);
 555         assert(name);
 556         assert(t);
 557
 558         if (!dual_timestamp_is_set(t))
 559                 return;
 560
 561         fprintf(f, "%s="USEC_FMT" "USEC_FMT"\n",
 562                 name,
 563                 t->realtime,
 564                 t->monotonic);
 565 }
 566
 567 int dual_timestamp_deserialize(const char *value, dual_timestamp *t) {
 568         uint64_t a, b;
 569         int r, pos;
 570
 571         assert(value);
 572         assert(t);
 573
 574         pos = strspn(value, WHITESPACE);
 575         if (value[pos] == '-')
 576                 return -EINVAL;
 577         pos += strspn(value + pos, DIGITS);
 578         pos += strspn(value + pos, WHITESPACE);
 579         if (value[pos] == '-')
 580                 return -EINVAL;
 581
 582         r = sscanf(value, "%" PRIu64 "%" PRIu64 "%n", &a, &b, &pos);
 583         if (r != 2) {
 584                 log_debug("Failed to parse dual timestamp value \"%s\".", value);
 585                 return -EINVAL;
 586         }
 587
 588         if (value[pos] != '\0')
 589                 /* trailing garbage */
 590                 return -EINVAL;
 591
 592         t->realtime = a;
 593         t->monotonic = b;
 594
 595         return 0;
 596 }
 597
 598 #endif // 0
 599 int timestamp_deserialize(const char *value, usec_t *timestamp) {
 600         int r;
 601
 602         assert(value);
 603
 604         r = safe_atou64(value, timestamp);
 605         if (r < 0)
 606                 return log_debug_errno(r, "Failed to parse timestamp value \"%s\": %m", value);
 607
 608         return r;
 609 }
 610
 611 #if 0 /// UNNEEDED by elogind
 612 static int parse_timestamp_impl(const char *t, usec_t *usec, bool with_tz) {
 613         static const struct {
 614                 const char *name;
 615                 const int nr;
 616         } day_nr[] = {
 617                 { "Sunday",    0 },
 618                 { "Sun",       0 },
 619                 { "Monday",    1 },
 620                 { "Mon",       1 },
 621                 { "Tuesday",   2 },
 622                 { "Tue",       2 },
 623                 { "Wednesday", 3 },
 624                 { "Wed",       3 },
 625                 { "Thursday",  4 },
 626                 { "Thu",       4 },
 627                 { "Friday",    5 },
 628                 { "Fri",       5 },
 629                 { "Saturday",  6 },
 630                 { "Sat",       6 },
 631         };
 632
 633         const char *k, *utc = NULL, *tzn = NULL;
 634         struct tm tm, copy;
 635         time_t x;
 636         usec_t x_usec, plus = 0, minus = 0, ret;
 637         int r, weekday = -1, dst = -1;
 638         unsigned i;
 639
 640         /*
 641          * Allowed syntaxes:
 642          *
 643          *   2012-09-22 16:34:22
 644          *   2012-09-22 16:34     (seconds will be set to 0)
 645          *   2012-09-22           (time will be set to 00:00:00)
 646          *   16:34:22             (date will be set to today)
 647          *   16:34                (date will be set to today, seconds to 0)
 648          *   now
 649          *   yesterday            (time is set to 00:00:00)
 650          *   today                (time is set to 00:00:00)
 651          *   tomorrow             (time is set to 00:00:00)
 652          *   +5min
 653          *   -5days
 654          *   @2147483647          (seconds since epoch)
 655          *
 656          */
 657
 658         assert(t);
 659         assert(usec);
 660
 661         if (t[0] == '@' && !with_tz)
 662                 return parse_sec(t + 1, usec);
 663
 664         ret = now(CLOCK_REALTIME);
 665
 666         if (!with_tz) {
 667                 if (streq(t, "now"))
 668                         goto finish;
 669
 670                 else if (t[0] == '+') {
 671                         r = parse_sec(t+1, &plus);
 672                         if (r < 0)
 673                                 return r;
 674
 675                         goto finish;
 676
 677                 } else if (t[0] == '-') {
 678                         r = parse_sec(t+1, &minus);
 679                         if (r < 0)
 680                                 return r;
 681
 682                         goto finish;
 683
 684                 } else if ((k = endswith(t, " ago"))) {
 685                         t = strndupa(t, k - t);
 686
 687                         r = parse_sec(t, &minus);
 688                         if (r < 0)
 689                                 return r;
 690
 691                         goto finish;
 692
 693                 } else if ((k = endswith(t, " left"))) {
 694                         t = strndupa(t, k - t);
 695
 696                         r = parse_sec(t, &plus);
 697                         if (r < 0)
 698                                 return r;
 699
 700                         goto finish;
 701                 }
 702
 703                 /* See if the timestamp is suffixed with UTC */
 704                 utc = endswith_no_case(t, " UTC");
 705                 if (utc)
 706                         t = strndupa(t, utc - t);
 707                 else {
 708                         const char *e = NULL;
 709                         int j;
 710
 711                         tzset();
 712
 713                         /* See if the timestamp is suffixed by either the DST or non-DST local timezone. Note that we only
 714                         * support the local timezones here, nothing else. Not because we wouldn't want to, but simply because
 715                         * there are no nice APIs available to cover this. By accepting the local time zone strings, we make
 716                         * sure that all timestamps written by format_timestamp() can be parsed correctly, even though we don't
 717                         * support arbitrary timezone specifications.  */
 718
 719                         for (j = 0; j <= 1; j++) {
 720
 721                                 if (isempty(tzname[j]))
 722                                         continue;
 723
 724                                 e = endswith_no_case(t, tzname[j]);
 725                                 if (!e)
 726                                         continue;
 727                                 if (e == t)
 728                                         continue;
 729                                 if (e[-1] != ' ')
 730                                         continue;
 731
 732                                 break;
 733                         }
 734
 735                         if (IN_SET(j, 0, 1)) {
 736                                 /* Found one of the two timezones specified. */
 737                                 t = strndupa(t, e - t - 1);
 738                                 dst = j;
 739                                 tzn = tzname[j];
 740                         }
 741                 }
 742         }
 743
 744         x = (time_t) (ret / USEC_PER_SEC);
 745         x_usec = 0;
 746
 747         if (!localtime_or_gmtime_r(&x, &tm, utc))
 748                 return -EINVAL;
 749
 750         if (!with_tz) {
 751                 tm.tm_isdst = dst;
 752                 if (tzn)
 753                         tm.tm_zone = tzn;
 754         }
 755
 756         if (streq(t, "today")) {
 757                 tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
 758                 goto from_tm;
 759
 760         } else if (streq(t, "yesterday")) {
 761                 tm.tm_mday--;
 762                 tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
 763                 goto from_tm;
 764
 765         } else if (streq(t, "tomorrow")) {
 766                 tm.tm_mday++;
 767                 tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
 768                 goto from_tm;
 769         }
 770
 771         for (i = 0; i < ELEMENTSOF(day_nr); i++) {
 772                 size_t skip;
 773
 774                 if (!startswith_no_case(t, day_nr[i].name))
 775                         continue;
 776
 777                 skip = strlen(day_nr[i].name);
 778                 if (t[skip] != ' ')
 779                         continue;
 780
 781                 weekday = day_nr[i].nr;
 782                 t += skip + 1;
 783                 break;
 784         }
 785
 786         copy = tm;
 787         k = strptime(t, "%y-%m-%d %H:%M:%S", &tm);
 788         if (k) {
 789                 if (*k == '.')
 790                         goto parse_usec;
 791                 else if (*k == 0)
 792                         goto from_tm;
 793         }
 794
 795         tm = copy;
 796         k = strptime(t, "%Y-%m-%d %H:%M:%S", &tm);
 797         if (k) {
 798                 if (*k == '.')
 799                         goto parse_usec;
 800                 else if (*k == 0)
 801                         goto from_tm;
 802         }
 803
 804         tm = copy;
 805         k = strptime(t, "%y-%m-%d %H:%M", &tm);
 806         if (k && *k == 0) {
 807                 tm.tm_sec = 0;
 808                 goto from_tm;
 809         }
 810
 811         tm = copy;
 812         k = strptime(t, "%Y-%m-%d %H:%M", &tm);
 813         if (k && *k == 0) {
 814                 tm.tm_sec = 0;
 815                 goto from_tm;
 816         }
 817
 818         tm = copy;
 819         k = strptime(t, "%y-%m-%d", &tm);
 820         if (k && *k == 0) {
 821                 tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
 822                 goto from_tm;
 823         }
 824
 825         tm = copy;
 826         k = strptime(t, "%Y-%m-%d", &tm);
 827         if (k && *k == 0) {
 828                 tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
 829                 goto from_tm;
 830         }
 831
 832         tm = copy;
 833         k = strptime(t, "%H:%M:%S", &tm);
 834         if (k) {
 835                 if (*k == '.')
 836                         goto parse_usec;
 837                 else if (*k == 0)
 838                         goto from_tm;
 839         }
 840
 841         tm = copy;
 842         k = strptime(t, "%H:%M", &tm);
 843         if (k && *k == 0) {
 844                 tm.tm_sec = 0;
 845                 goto from_tm;
 846         }
 847
 848         return -EINVAL;
 849
 850 parse_usec:
 851         {
 852                 unsigned add;
 853
 854                 k++;
 855                 r = parse_fractional_part_u(&k, 6, &add);
 856                 if (r < 0)
 857                         return -EINVAL;
 858
 859                 if (*k)
 860                         return -EINVAL;
 861
 862                 x_usec = add;
 863         }
 864
 865 from_tm:
 866         x = mktime_or_timegm(&tm, utc);
 867         if (x < 0)
 868                 return -EINVAL;
 869
 870         if (weekday >= 0 && tm.tm_wday != weekday)
 871                 return -EINVAL;
 872
 873         ret = (usec_t) x * USEC_PER_SEC + x_usec;
 874         if (ret > USEC_TIMESTAMP_FORMATTABLE_MAX)
 875                 return -EINVAL;
 876
 877 finish:
 878         if (ret + plus < ret) /* overflow? */
 879                 return -EINVAL;
 880         ret += plus;
 881         if (ret > USEC_TIMESTAMP_FORMATTABLE_MAX)
 882                 return -EINVAL;
 883
 884         if (ret >= minus)
 885                 ret -= minus;
 886         else
 887                 return -EINVAL;
 888
 889         *usec = ret;
 890
 891         return 0;
 892 }
 893 #endif // 0
 894
 895 typedef struct ParseTimestampResult {
 896         usec_t usec;
 897         int return_value;
 898 } ParseTimestampResult;
 899
 900 int parse_timestamp(const char *t, usec_t *usec) {
 901         char *last_space, *timezone = NULL;
 902         ParseTimestampResult *shared, tmp;
 903         int r;
 904         pid_t pid;
 905
 906         last_space = strrchr(t, ' ');
 907         if (last_space != NULL && timezone_is_valid(last_space + 1))
 908                 timezone = last_space + 1;
 909
 910         if (timezone == NULL || endswith_no_case(t, " UTC"))
 911                 return parse_timestamp_impl(t, usec, false);
 912
 913         t = strndupa(t, last_space - t);
 914
 915         shared = mmap(NULL, sizeof *shared, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0);
 916         if (shared == MAP_FAILED)
 917                 return negative_errno();
 918
 919         pid = fork();
 920
 921         if (pid == -1) {
 922                 int fork_errno = errno;
 923                 (void) munmap(shared, sizeof *shared);
 924                 return -fork_errno;
 925         }
 926
 927         if (pid == 0) {
 928                 if (setenv("TZ", timezone, 1) != 0) {
 929                         shared->return_value = negative_errno();
 930                         _exit(EXIT_FAILURE);
 931                 }
 932
 933                 tzset();
 934
 935                 shared->return_value = parse_timestamp_impl(t, &shared->usec, true);
 936
 937                 _exit(EXIT_SUCCESS);
 938         }
 939
 940         r = wait_for_terminate(pid, NULL);
 941         if (r < 0) {
 942                 (void) munmap(shared, sizeof *shared);
 943                 return r;
 944         }
 945
 946         tmp = *shared;
 947         if (munmap(shared, sizeof *shared) != 0)
 948                 return negative_errno();
 949
 950         if (tmp.return_value == 0)
 951                 *usec = tmp.usec;
 952
 953         return tmp.return_value;
 954 }
 955
 956 static char* extract_multiplier(char *p, usec_t *multiplier) {
 957         static const struct {
 958                 const char *suffix;
 959                 usec_t usec;
 960         } table[] = {
 961                 { "seconds", USEC_PER_SEC    },
 962                 { "second",  USEC_PER_SEC    },
 963                 { "sec",     USEC_PER_SEC    },
 964                 { "s",       USEC_PER_SEC    },
 965                 { "minutes", USEC_PER_MINUTE },
 966                 { "minute",  USEC_PER_MINUTE },
 967                 { "min",     USEC_PER_MINUTE },
 968                 { "months",  USEC_PER_MONTH  },
 969                 { "month",   USEC_PER_MONTH  },
 970                 { "M",       USEC_PER_MONTH  },
 971                 { "msec",    USEC_PER_MSEC   },
 972                 { "ms",      USEC_PER_MSEC   },
 973                 { "m",       USEC_PER_MINUTE },
 974                 { "hours",   USEC_PER_HOUR   },
 975                 { "hour",    USEC_PER_HOUR   },
 976                 { "hr",      USEC_PER_HOUR   },
 977                 { "h",       USEC_PER_HOUR   },
 978                 { "days",    USEC_PER_DAY    },
 979                 { "day",     USEC_PER_DAY    },
 980                 { "d",       USEC_PER_DAY    },
 981                 { "weeks",   USEC_PER_WEEK   },
 982                 { "week",    USEC_PER_WEEK   },
 983                 { "w",       USEC_PER_WEEK   },
 984                 { "years",   USEC_PER_YEAR   },
 985                 { "year",    USEC_PER_YEAR   },
 986                 { "y",       USEC_PER_YEAR   },
 987                 { "usec",    1ULL            },
 988                 { "us",      1ULL            },
 989                 { "µs",      1ULL            },
 990         };
 991         unsigned i;
 992
 993         for (i = 0; i < ELEMENTSOF(table); i++) {
 994                 char *e;
 995
 996                 e = startswith(p, table[i].suffix);
 997                 if (e) {
 998                         *multiplier = table[i].usec;
 999                         return e;
1000                 }
1001         }
1002
1003         return p;
1004 }
1005
1006 int parse_time(const char *t, usec_t *usec, usec_t default_unit) {
1007         const char *p, *s;
1008         usec_t r = 0;
1009         bool something = false;
1010
1011         assert(t);
1012         assert(usec);
1013         assert(default_unit > 0);
1014
1015         p = t;
1016
1017         p += strspn(p, WHITESPACE);
1018         s = startswith(p, "infinity");
1019         if (s) {
1020                 s += strspn(s, WHITESPACE);
1021                 if (*s != 0)
1022                         return -EINVAL;
1023
1024                 *usec = USEC_INFINITY;
1025                 return 0;
1026         }
1027
1028         for (;;) {
1029                 long long l, z = 0;
1030                 char *e;
1031                 unsigned n = 0;
1032                 usec_t multiplier = default_unit, k;
1033
1034                 p += strspn(p, WHITESPACE);
1035
1036                 if (*p == 0) {
1037                         if (!something)
1038                                 return -EINVAL;
1039
1040                         break;
1041                 }
1042
1043                 errno = 0;
1044                 l = strtoll(p, &e, 10);
1045                 if (errno > 0)
1046                         return -errno;
1047                 if (l < 0)
1048                         return -ERANGE;
1049
1050                 if (*e == '.') {
1051                         char *b = e + 1;
1052
1053                         errno = 0;
1054                         z = strtoll(b, &e, 10);
1055                         if (errno > 0)
1056                                 return -errno;
1057
1058                         if (z < 0)
1059                                 return -ERANGE;
1060
1061                         if (e == b)
1062                                 return -EINVAL;
1063
1064                         n = e - b;
1065
1066                 } else if (e == p)
1067                         return -EINVAL;
1068
1069                 e += strspn(e, WHITESPACE);
1070                 p = extract_multiplier(e, &multiplier);
1071
1072                 something = true;
1073
1074                 k = (usec_t) z * multiplier;
1075
1076                 for (; n > 0; n--)
1077                         k /= 10;
1078
1079                 r += (usec_t) l * multiplier + k;
1080         }
1081
1082         *usec = r;
1083
1084         return 0;
1085 }
1086
1087 int parse_sec(const char *t, usec_t *usec) {
1088         return parse_time(t, usec, USEC_PER_SEC);
1089 }
1090
1091 #if 0 /// UNNEEDED by elogind
1092 int parse_sec_fix_0(const char *t, usec_t *usec) {
1093         t += strspn(t, WHITESPACE);
1094         if (streq(t, "0")) {
1095                 *usec = USEC_INFINITY;
1096                 return 0;
1097         }
1098
1099         return parse_sec(t, usec);
1100 }
1101
1102 int parse_nsec(const char *t, nsec_t *nsec) {
1103         static const struct {
1104                 const char *suffix;
1105                 nsec_t nsec;
1106         } table[] = {
1107                 { "seconds", NSEC_PER_SEC },
1108                 { "second", NSEC_PER_SEC },
1109                 { "sec", NSEC_PER_SEC },
1110                 { "s", NSEC_PER_SEC },
1111                 { "minutes", NSEC_PER_MINUTE },
1112                 { "minute", NSEC_PER_MINUTE },
1113                 { "min", NSEC_PER_MINUTE },
1114                 { "months", NSEC_PER_MONTH },
1115                 { "month", NSEC_PER_MONTH },
1116                 { "msec", NSEC_PER_MSEC },
1117                 { "ms", NSEC_PER_MSEC },
1118                 { "m", NSEC_PER_MINUTE },
1119                 { "hours", NSEC_PER_HOUR },
1120                 { "hour", NSEC_PER_HOUR },
1121                 { "hr", NSEC_PER_HOUR },
1122                 { "h", NSEC_PER_HOUR },
1123                 { "days", NSEC_PER_DAY },
1124                 { "day", NSEC_PER_DAY },
1125                 { "d", NSEC_PER_DAY },
1126                 { "weeks", NSEC_PER_WEEK },
1127                 { "week", NSEC_PER_WEEK },
1128                 { "w", NSEC_PER_WEEK },
1129                 { "years", NSEC_PER_YEAR },
1130                 { "year", NSEC_PER_YEAR },
1131                 { "y", NSEC_PER_YEAR },
1132                 { "usec", NSEC_PER_USEC },
1133                 { "us", NSEC_PER_USEC },
1134                 { "µs", NSEC_PER_USEC },
1135                 { "nsec", 1ULL },
1136                 { "ns", 1ULL },
1137                 { "", 1ULL }, /* default is nsec */
1138         };
1139
1140         const char *p, *s;
1141         nsec_t r = 0;
1142         bool something = false;
1143
1144         assert(t);
1145         assert(nsec);
1146
1147         p = t;
1148
1149         p += strspn(p, WHITESPACE);
1150         s = startswith(p, "infinity");
1151         if (s) {
1152                 s += strspn(s, WHITESPACE);
1153                 if (*s != 0)
1154                         return -EINVAL;
1155
1156                 *nsec = NSEC_INFINITY;
1157                 return 0;
1158         }
1159
1160         for (;;) {
1161                 long long l, z = 0;
1162                 char *e;
1163                 unsigned i, n = 0;
1164
1165                 p += strspn(p, WHITESPACE);
1166
1167                 if (*p == 0) {
1168                         if (!something)
1169                                 return -EINVAL;
1170
1171                         break;
1172                 }
1173
1174                 errno = 0;
1175                 l = strtoll(p, &e, 10);
1176
1177                 if (errno > 0)
1178                         return -errno;
1179
1180                 if (l < 0)
1181                         return -ERANGE;
1182
1183                 if (*e == '.') {
1184                         char *b = e + 1;
1185
1186                         errno = 0;
1187                         z = strtoll(b, &e, 10);
1188                         if (errno > 0)
1189                                 return -errno;
1190
1191                         if (z < 0)
1192                                 return -ERANGE;
1193
1194                         if (e == b)
1195                                 return -EINVAL;
1196
1197                         n = e - b;
1198
1199                 } else if (e == p)
1200                         return -EINVAL;
1201
1202                 e += strspn(e, WHITESPACE);
1203
1204                 for (i = 0; i < ELEMENTSOF(table); i++)
1205                         if (startswith(e, table[i].suffix)) {
1206                                 nsec_t k = (nsec_t) z * table[i].nsec;
1207
1208                                 for (; n > 0; n--)
1209                                         k /= 10;
1210
1211                                 r += (nsec_t) l * table[i].nsec + k;
1212                                 p = e + strlen(table[i].suffix);
1213
1214                                 something = true;
1215                                 break;
1216                         }
1217
1218                 if (i >= ELEMENTSOF(table))
1219                         return -EINVAL;
1220
1221         }
1222
1223         *nsec = r;
1224
1225         return 0;
1226 }
1227
1228 bool ntp_synced(void) {
1229         struct timex txc = {};
1230
1231         if (adjtimex(&txc) < 0)
1232                 return false;
1233
1234         if (txc.status & STA_UNSYNC)
1235                 return false;
1236
1237         return true;
1238 }
1239
1240 int get_timezones(char ***ret) {
1241         _cleanup_fclose_ FILE *f = NULL;
1242         _cleanup_strv_free_ char **zones = NULL;
1243         size_t n_zones = 0, n_allocated = 0;
1244
1245         assert(ret);
1246
1247         zones = strv_new("UTC", NULL);
1248         if (!zones)
1249                 return -ENOMEM;
1250
1251         n_allocated = 2;
1252         n_zones = 1;
1253
1254         f = fopen("/usr/share/zoneinfo/zone.tab", "re");
1255         if (f) {
1256                 char l[LINE_MAX];
1257
1258                 FOREACH_LINE(l, f, return -errno) {
1259                         char *p, *w;
1260                         size_t k;
1261
1262                         p = strstrip(l);
1263
1264                         if (isempty(p) || *p == '#')
1265                                 continue;
1266
1267                         /* Skip over country code */
1268                         p += strcspn(p, WHITESPACE);
1269                         p += strspn(p, WHITESPACE);
1270
1271                         /* Skip over coordinates */
1272                         p += strcspn(p, WHITESPACE);
1273                         p += strspn(p, WHITESPACE);
1274
1275                         /* Found timezone name */
1276                         k = strcspn(p, WHITESPACE);
1277                         if (k <= 0)
1278                                 continue;
1279
1280                         w = strndup(p, k);
1281                         if (!w)
1282                                 return -ENOMEM;
1283
1284                         if (!GREEDY_REALLOC(zones, n_allocated, n_zones + 2)) {
1285                                 free(w);
1286                                 return -ENOMEM;
1287                         }
1288
1289                         zones[n_zones++] = w;
1290                         zones[n_zones] = NULL;
1291                 }
1292
1293                 strv_sort(zones);
1294
1295         } else if (errno != ENOENT)
1296                 return -errno;
1297
1298         *ret = zones;
1299         zones = NULL;
1300
1301         return 0;
1302 }
1303
1304 bool timezone_is_valid(const char *name) {
1305         bool slash = false;
1306         const char *p, *t;
1307         struct stat st;
1308
1309         if (isempty(name))
1310                 return false;
1311
1312         if (name[0] == '/')
1313                 return false;
1314
1315         for (p = name; *p; p++) {
1316                 if (!(*p >= '0' && *p <= '9') &&
1317                     !(*p >= 'a' && *p <= 'z') &&
1318                     !(*p >= 'A' && *p <= 'Z') &&
1319                     !(*p == '-' || *p == '_' || *p == '+' || *p == '/'))
1320                         return false;
1321
1322                 if (*p == '/') {
1323
1324                         if (slash)
1325                                 return false;
1326
1327                         slash = true;
1328                 } else
1329                         slash = false;
1330         }
1331
1332         if (slash)
1333                 return false;
1334
1335         t = strjoina("/usr/share/zoneinfo/", name);
1336         if (stat(t, &st) < 0)
1337                 return false;
1338
1339         if (!S_ISREG(st.st_mode))
1340                 return false;
1341
1342         return true;
1343 }
1344
1345 #endif // 0
1346 bool clock_boottime_supported(void) {
1347         static int supported = -1;
1348
1349         /* Note that this checks whether CLOCK_BOOTTIME is available in general as well as available for timerfds()! */
1350
1351         if (supported < 0) {
1352                 int fd;
1353
1354                 fd = timerfd_create(CLOCK_BOOTTIME, TFD_NONBLOCK|TFD_CLOEXEC);
1355                 if (fd < 0)
1356                         supported = false;
1357                 else {
1358                         safe_close(fd);
1359                         supported = true;
1360                 }
1361         }
1362
1363         return supported;
1364 }
1365
1366 #if 0 /// UNNEEDED by elogind
1367 clockid_t clock_boottime_or_monotonic(void) {
1368         if (clock_boottime_supported())
1369                 return CLOCK_BOOTTIME;
1370         else
1371                 return CLOCK_MONOTONIC;
1372 }
1373 #endif // 0
1374
1375 bool clock_supported(clockid_t clock) {
1376         struct timespec ts;
1377
1378         switch (clock) {
1379
1380         case CLOCK_MONOTONIC:
1381         case CLOCK_REALTIME:
1382                 return true;
1383
1384         case CLOCK_BOOTTIME:
1385                 return clock_boottime_supported();
1386
1387         case CLOCK_BOOTTIME_ALARM:
1388                 if (!clock_boottime_supported())
1389                         return false;
1390
1391                 /* fall through */
1392
1393         default:
1394                 /* For everything else, check properly */
1395                 return clock_gettime(clock, &ts) >= 0;
1396         }
1397 }
1398
1399 #if 0 /// UNNEEDED by elogind
1400 int get_timezone(char **tz) {
1401         _cleanup_free_ char *t = NULL;
1402         const char *e;
1403         char *z;
1404         int r;
1405
1406         r = readlink_malloc("/etc/localtime", &t);
1407         if (r < 0)
1408                 return r; /* returns EINVAL if not a symlink */
1409
1410         e = path_startswith(t, "/usr/share/zoneinfo/");
1411         if (!e)
1412                 e = path_startswith(t, "../usr/share/zoneinfo/");
1413         if (!e)
1414                 return -EINVAL;
1415
1416         if (!timezone_is_valid(e))
1417                 return -EINVAL;
1418
1419         z = strdup(e);
1420         if (!z)
1421                 return -ENOMEM;
1422
1423         *tz = z;
1424         return 0;
1425 }
1426
1427 time_t mktime_or_timegm(struct tm *tm, bool utc) {
1428         return utc ? timegm(tm) : mktime(tm);
1429 }
1430 #endif // 0
1431
1432 struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc) {
1433         return utc ? gmtime_r(t, tm) : localtime_r(t, tm);
1434 }
1435
1436 #if 0 /// UNNEEDED by elogind
1437 unsigned long usec_to_jiffies(usec_t u) {
1438         static thread_local unsigned long hz = 0;
1439         long r;
1440
1441         if (hz == 0) {
1442                 r = sysconf(_SC_CLK_TCK);
1443
1444                 assert(r > 0);
1445                 hz = r;
1446         }
1447
1448         return DIV_ROUND_UP(u , USEC_PER_SEC / hz);
1449 }
1450
1451 usec_t usec_shift_clock(usec_t x, clockid_t from, clockid_t to) {
1452         usec_t a, b;
1453
1454         if (x == USEC_INFINITY)
1455                 return USEC_INFINITY;
1456         if (map_clock_id(from) == map_clock_id(to))
1457                 return x;
1458
1459         a = now(from);
1460         b = now(to);
1461
1462         if (x > a)
1463                 /* x lies in the future */
1464                 return usec_add(b, usec_sub_unsigned(x, a));
1465         else
1466                 /* x lies in the past */
1467                 return usec_sub_unsigned(b, usec_sub_unsigned(a, x));
1468 }
1469 #endif // 0