src/shared/time-util.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <time.h>
  23 #include <string.h>
  24 #include <sys/timex.h>
  25 #include <sys/timerfd.h>
  26
  27 #include "util.h"
  28 #include "time-util.h"
  29 #include "strv.h"
  30
  31 usec_t now(clockid_t clock_id) {
  32         struct timespec ts;
  33
  34         assert_se(clock_gettime(clock_id, &ts) == 0);
  35
  36         return timespec_load(&ts);
  37 }
  38
  39 dual_timestamp* dual_timestamp_get(dual_timestamp *ts) {
  40         assert(ts);
  41
  42         ts->realtime = now(CLOCK_REALTIME);
  43         ts->monotonic = now(CLOCK_MONOTONIC);
  44
  45         return ts;
  46 }
  47
  48 dual_timestamp* dual_timestamp_from_realtime(dual_timestamp *ts, usec_t u) {
  49         int64_t delta;
  50         assert(ts);
  51
  52         if (u == USEC_INFINITY || u <= 0) {
  53                 ts->realtime = ts->monotonic = u;
  54                 return ts;
  55         }
  56
  57         ts->realtime = u;
  58
  59         delta = (int64_t) now(CLOCK_REALTIME) - (int64_t) u;
  60         ts->monotonic = now(CLOCK_MONOTONIC);
  61
  62         if ((int64_t) ts->monotonic > delta)
  63                 ts->monotonic -= delta;
  64         else
  65                 ts->monotonic = 0;
  66
  67         return ts;
  68 }
  69
  70 dual_timestamp* dual_timestamp_from_monotonic(dual_timestamp *ts, usec_t u) {
  71         int64_t delta;
  72         assert(ts);
  73
  74         if (u == USEC_INFINITY) {
  75                 ts->realtime = ts->monotonic = USEC_INFINITY;
  76                 return ts;
  77         }
  78
  79         ts->monotonic = u;
  80         delta = (int64_t) now(CLOCK_MONOTONIC) - (int64_t) u;
  81
  82         ts->realtime = now(CLOCK_REALTIME);
  83         if ((int64_t) ts->realtime > delta)
  84                 ts->realtime -= delta;
  85         else
  86                 ts->realtime = 0;
  87
  88         return ts;
  89 }
  90
  91 usec_t timespec_load(const struct timespec *ts) {
  92         assert(ts);
  93
  94         if (ts->tv_sec == (time_t) -1 &&
  95             ts->tv_nsec == (long) -1)
  96                 return USEC_INFINITY;
  97
  98         if ((usec_t) ts->tv_sec > (UINT64_MAX - (ts->tv_nsec / NSEC_PER_USEC)) / USEC_PER_SEC)
  99                 return USEC_INFINITY;
 100
 101         return
 102                 (usec_t) ts->tv_sec * USEC_PER_SEC +
 103                 (usec_t) ts->tv_nsec / NSEC_PER_USEC;
 104 }
 105
 106 struct timespec *timespec_store(struct timespec *ts, usec_t u)  {
 107         assert(ts);
 108
 109         if (u == USEC_INFINITY) {
 110                 ts->tv_sec = (time_t) -1;
 111                 ts->tv_nsec = (long) -1;
 112                 return ts;
 113         }
 114
 115         ts->tv_sec = (time_t) (u / USEC_PER_SEC);
 116         ts->tv_nsec = (long int) ((u % USEC_PER_SEC) * NSEC_PER_USEC);
 117
 118         return ts;
 119 }
 120
 121 usec_t timeval_load(const struct timeval *tv) {
 122         assert(tv);
 123
 124         if (tv->tv_sec == (time_t) -1 &&
 125             tv->tv_usec == (suseconds_t) -1)
 126                 return USEC_INFINITY;
 127
 128         if ((usec_t) tv->tv_sec > (UINT64_MAX - tv->tv_usec) / USEC_PER_SEC)
 129                 return USEC_INFINITY;
 130
 131         return
 132                 (usec_t) tv->tv_sec * USEC_PER_SEC +
 133                 (usec_t) tv->tv_usec;
 134 }
 135
 136 struct timeval *timeval_store(struct timeval *tv, usec_t u) {
 137         assert(tv);
 138
 139         if (u == USEC_INFINITY) {
 140                 tv->tv_sec = (time_t) -1;
 141                 tv->tv_usec = (suseconds_t) -1;
 142         } else {
 143                 tv->tv_sec = (time_t) (u / USEC_PER_SEC);
 144                 tv->tv_usec = (suseconds_t) (u % USEC_PER_SEC);
 145         }
 146
 147         return tv;
 148 }
 149
 150 static char *format_timestamp_internal(char *buf, size_t l, usec_t t, bool utc) {
 151         struct tm tm;
 152         time_t sec;
 153
 154         assert(buf);
 155         assert(l > 0);
 156
 157         if (t <= 0 || t == USEC_INFINITY)
 158                 return NULL;
 159
 160         sec = (time_t) (t / USEC_PER_SEC);
 161
 162         if (utc)
 163                 gmtime_r(&sec, &tm);
 164         else
 165                 localtime_r(&sec, &tm);
 166         if (strftime(buf, l, "%a %Y-%m-%d %H:%M:%S %Z", &tm) <= 0)
 167                 return NULL;
 168
 169         return buf;
 170 }
 171
 172 char *format_timestamp(char *buf, size_t l, usec_t t) {
 173         return format_timestamp_internal(buf, l, t, false);
 174 }
 175
 176 char *format_timestamp_utc(char *buf, size_t l, usec_t t) {
 177         return format_timestamp_internal(buf, l, t, true);
 178 }
 179
 180 static char *format_timestamp_internal_us(char *buf, size_t l, usec_t t, bool utc) {
 181         struct tm tm;
 182         time_t sec;
 183
 184         assert(buf);
 185         assert(l > 0);
 186
 187         if (t <= 0 || t == USEC_INFINITY)
 188                 return NULL;
 189
 190         sec = (time_t) (t / USEC_PER_SEC);
 191         if (utc)
 192                 gmtime_r(&sec, &tm);
 193         else
 194                 localtime_r(&sec, &tm);
 195
 196         if (strftime(buf, l, "%a %Y-%m-%d %H:%M:%S", &tm) <= 0)
 197                 return NULL;
 198         snprintf(buf + strlen(buf), l - strlen(buf), ".%06llu", (unsigned long long) (t % USEC_PER_SEC));
 199         if (strftime(buf + strlen(buf), l - strlen(buf), " %Z", &tm) <= 0)
 200                 return NULL;
 201
 202         return buf;
 203 }
 204
 205 char *format_timestamp_us(char *buf, size_t l, usec_t t) {
 206         return format_timestamp_internal_us(buf, l, t, false);
 207 }
 208
 209 char *format_timestamp_us_utc(char *buf, size_t l, usec_t t) {
 210         return format_timestamp_internal_us(buf, l, t, true);
 211 }
 212
 213 char *format_timestamp_relative(char *buf, size_t l, usec_t t) {
 214         const char *s;
 215         usec_t n, d;
 216
 217         if (t <= 0 || t == USEC_INFINITY)
 218                 return NULL;
 219
 220         n = now(CLOCK_REALTIME);
 221         if (n > t) {
 222                 d = n - t;
 223                 s = "ago";
 224         } else {
 225                 d = t - n;
 226                 s = "left";
 227         }
 228
 229         if (d >= USEC_PER_YEAR)
 230                 snprintf(buf, l, USEC_FMT " years " USEC_FMT " months %s",
 231                          d / USEC_PER_YEAR,
 232                          (d % USEC_PER_YEAR) / USEC_PER_MONTH, s);
 233         else if (d >= USEC_PER_MONTH)
 234                 snprintf(buf, l, USEC_FMT " months " USEC_FMT " days %s",
 235                          d / USEC_PER_MONTH,
 236                          (d % USEC_PER_MONTH) / USEC_PER_DAY, s);
 237         else if (d >= USEC_PER_WEEK)
 238                 snprintf(buf, l, USEC_FMT " weeks " USEC_FMT " days %s",
 239                          d / USEC_PER_WEEK,
 240                          (d % USEC_PER_WEEK) / USEC_PER_DAY, s);
 241         else if (d >= 2*USEC_PER_DAY)
 242                 snprintf(buf, l, USEC_FMT " days %s", d / USEC_PER_DAY, s);
 243         else if (d >= 25*USEC_PER_HOUR)
 244                 snprintf(buf, l, "1 day " USEC_FMT "h %s",
 245                          (d - USEC_PER_DAY) / USEC_PER_HOUR, s);
 246         else if (d >= 6*USEC_PER_HOUR)
 247                 snprintf(buf, l, USEC_FMT "h %s",
 248                          d / USEC_PER_HOUR, s);
 249         else if (d >= USEC_PER_HOUR)
 250                 snprintf(buf, l, USEC_FMT "h " USEC_FMT "min %s",
 251                          d / USEC_PER_HOUR,
 252                          (d % USEC_PER_HOUR) / USEC_PER_MINUTE, s);
 253         else if (d >= 5*USEC_PER_MINUTE)
 254                 snprintf(buf, l, USEC_FMT "min %s",
 255                          d / USEC_PER_MINUTE, s);
 256         else if (d >= USEC_PER_MINUTE)
 257                 snprintf(buf, l, USEC_FMT "min " USEC_FMT "s %s",
 258                          d / USEC_PER_MINUTE,
 259                          (d % USEC_PER_MINUTE) / USEC_PER_SEC, s);
 260         else if (d >= USEC_PER_SEC)
 261                 snprintf(buf, l, USEC_FMT "s %s",
 262                          d / USEC_PER_SEC, s);
 263         else if (d >= USEC_PER_MSEC)
 264                 snprintf(buf, l, USEC_FMT "ms %s",
 265                          d / USEC_PER_MSEC, s);
 266         else if (d > 0)
 267                 snprintf(buf, l, USEC_FMT"us %s",
 268                          d, s);
 269         else
 270                 snprintf(buf, l, "now");
 271
 272         buf[l-1] = 0;
 273         return buf;
 274 }
 275
 276 char *format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy) {
 277         static const struct {
 278                 const char *suffix;
 279                 usec_t usec;
 280         } table[] = {
 281                 { "y", USEC_PER_YEAR },
 282                 { "month", USEC_PER_MONTH },
 283                 { "w", USEC_PER_WEEK },
 284                 { "d", USEC_PER_DAY },
 285                 { "h", USEC_PER_HOUR },
 286                 { "min", USEC_PER_MINUTE },
 287                 { "s", USEC_PER_SEC },
 288                 { "ms", USEC_PER_MSEC },
 289                 { "us", 1 },
 290         };
 291
 292         unsigned i;
 293         char *p = buf;
 294         bool something = false;
 295
 296         assert(buf);
 297         assert(l > 0);
 298
 299         if (t == USEC_INFINITY) {
 300                 strncpy(p, "infinity", l-1);
 301                 p[l-1] = 0;
 302                 return p;
 303         }
 304
 305         if (t <= 0) {
 306                 strncpy(p, "0", l-1);
 307                 p[l-1] = 0;
 308                 return p;
 309         }
 310
 311         /* The result of this function can be parsed with parse_sec */
 312
 313         for (i = 0; i < ELEMENTSOF(table); i++) {
 314                 int k = 0;
 315                 size_t n;
 316                 bool done = false;
 317                 usec_t a, b;
 318
 319                 if (t <= 0)
 320                         break;
 321
 322                 if (t < accuracy && something)
 323                         break;
 324
 325                 if (t < table[i].usec)
 326                         continue;
 327
 328                 if (l <= 1)
 329                         break;
 330
 331                 a = t / table[i].usec;
 332                 b = t % table[i].usec;
 333
 334                 /* Let's see if we should shows this in dot notation */
 335                 if (t < USEC_PER_MINUTE && b > 0) {
 336                         usec_t cc;
 337                         int j;
 338
 339                         j = 0;
 340                         for (cc = table[i].usec; cc > 1; cc /= 10)
 341                                 j++;
 342
 343                         for (cc = accuracy; cc > 1; cc /= 10) {
 344                                 b /= 10;
 345                                 j--;
 346                         }
 347
 348                         if (j > 0) {
 349                                 k = snprintf(p, l,
 350                                              "%s"USEC_FMT".%0*llu%s",
 351                                              p > buf ? " " : "",
 352                                              a,
 353                                              j,
 354                                              (unsigned long long) b,
 355                                              table[i].suffix);
 356
 357                                 t = 0;
 358                                 done = true;
 359                         }
 360                 }
 361
 362                 /* No? Then let's show it normally */
 363                 if (!done) {
 364                         k = snprintf(p, l,
 365                                      "%s"USEC_FMT"%s",
 366                                      p > buf ? " " : "",
 367                                      a,
 368                                      table[i].suffix);
 369
 370                         t = b;
 371                 }
 372
 373                 n = MIN((size_t) k, l);
 374
 375                 l -= n;
 376                 p += n;
 377
 378                 something = true;
 379         }
 380
 381         *p = 0;
 382
 383         return buf;
 384 }
 385
 386 void dual_timestamp_serialize(FILE *f, const char *name, dual_timestamp *t) {
 387
 388         assert(f);
 389         assert(name);
 390         assert(t);
 391
 392         if (!dual_timestamp_is_set(t))
 393                 return;
 394
 395         fprintf(f, "%s="USEC_FMT" "USEC_FMT"\n",
 396                 name,
 397                 t->realtime,
 398                 t->monotonic);
 399 }
 400
 401 void dual_timestamp_deserialize(const char *value, dual_timestamp *t) {
 402         unsigned long long a, b;
 403
 404         assert(value);
 405         assert(t);
 406
 407         if (sscanf(value, "%llu %llu", &a, &b) != 2)
 408                 log_debug("Failed to parse finish timestamp value %s", value);
 409         else {
 410                 t->realtime = a;
 411                 t->monotonic = b;
 412         }
 413 }
 414
 415 int parse_timestamp(const char *t, usec_t *usec) {
 416         static const struct {
 417                 const char *name;
 418                 const int nr;
 419         } day_nr[] = {
 420                 { "Sunday",    0 },
 421                 { "Sun",       0 },
 422                 { "Monday",    1 },
 423                 { "Mon",       1 },
 424                 { "Tuesday",   2 },
 425                 { "Tue",       2 },
 426                 { "Wednesday", 3 },
 427                 { "Wed",       3 },
 428                 { "Thursday",  4 },
 429                 { "Thu",       4 },
 430                 { "Friday",    5 },
 431                 { "Fri",       5 },
 432                 { "Saturday",  6 },
 433                 { "Sat",       6 },
 434         };
 435
 436         const char *k;
 437         struct tm tm, copy;
 438         time_t x;
 439         usec_t plus = 0, minus = 0, ret;
 440         int r, weekday = -1;
 441         unsigned i;
 442
 443         /*
 444          * Allowed syntaxes:
 445          *
 446          *   2012-09-22 16:34:22
 447          *   2012-09-22 16:34     (seconds will be set to 0)
 448          *   2012-09-22           (time will be set to 00:00:00)
 449          *   16:34:22             (date will be set to today)
 450          *   16:34                (date will be set to today, seconds to 0)
 451          *   now
 452          *   yesterday            (time is set to 00:00:00)
 453          *   today                (time is set to 00:00:00)
 454          *   tomorrow             (time is set to 00:00:00)
 455          *   +5min
 456          *   -5days
 457          *   @2147483647          (seconds since epoch)
 458          *
 459          */
 460
 461         assert(t);
 462         assert(usec);
 463
 464         x = time(NULL);
 465         assert_se(localtime_r(&x, &tm));
 466         tm.tm_isdst = -1;
 467
 468         if (streq(t, "now"))
 469                 goto finish;
 470
 471         else if (streq(t, "today")) {
 472                 tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
 473                 goto finish;
 474
 475         } else if (streq(t, "yesterday")) {
 476                 tm.tm_mday --;
 477                 tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
 478                 goto finish;
 479
 480         } else if (streq(t, "tomorrow")) {
 481                 tm.tm_mday ++;
 482                 tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
 483                 goto finish;
 484
 485         } else if (t[0] == '+') {
 486                 r = parse_sec(t+1, &plus);
 487                 if (r < 0)
 488                         return r;
 489
 490                 goto finish;
 491
 492         } else if (t[0] == '-') {
 493                 r = parse_sec(t+1, &minus);
 494                 if (r < 0)
 495                         return r;
 496
 497                 goto finish;
 498
 499         } else if (t[0] == '@')
 500                 return parse_sec(t + 1, usec);
 501
 502         else if (endswith(t, " ago")) {
 503                 _cleanup_free_ char *z;
 504
 505                 z = strndup(t, strlen(t) - 4);
 506                 if (!z)
 507                         return -ENOMEM;
 508
 509                 r = parse_sec(z, &minus);
 510                 if (r < 0)
 511                         return r;
 512
 513                 goto finish;
 514         } else if (endswith(t, " left")) {
 515                 _cleanup_free_ char *z;
 516
 517                 z = strndup(t, strlen(t) - 4);
 518                 if (!z)
 519                         return -ENOMEM;
 520
 521                 r = parse_sec(z, &plus);
 522                 if (r < 0)
 523                         return r;
 524
 525                 goto finish;
 526         }
 527
 528         for (i = 0; i < ELEMENTSOF(day_nr); i++) {
 529                 size_t skip;
 530
 531                 if (!startswith_no_case(t, day_nr[i].name))
 532                         continue;
 533
 534                 skip = strlen(day_nr[i].name);
 535                 if (t[skip] != ' ')
 536                         continue;
 537
 538                 weekday = day_nr[i].nr;
 539                 t += skip + 1;
 540                 break;
 541         }
 542
 543         copy = tm;
 544         k = strptime(t, "%y-%m-%d %H:%M:%S", &tm);
 545         if (k && *k == 0)
 546                 goto finish;
 547
 548         tm = copy;
 549         k = strptime(t, "%Y-%m-%d %H:%M:%S", &tm);
 550         if (k && *k == 0)
 551                 goto finish;
 552
 553         tm = copy;
 554         k = strptime(t, "%y-%m-%d %H:%M", &tm);
 555         if (k && *k == 0) {
 556                 tm.tm_sec = 0;
 557                 goto finish;
 558         }
 559
 560         tm = copy;
 561         k = strptime(t, "%Y-%m-%d %H:%M", &tm);
 562         if (k && *k == 0) {
 563                 tm.tm_sec = 0;
 564                 goto finish;
 565         }
 566
 567         tm = copy;
 568         k = strptime(t, "%y-%m-%d", &tm);
 569         if (k && *k == 0) {
 570                 tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
 571                 goto finish;
 572         }
 573
 574         tm = copy;
 575         k = strptime(t, "%Y-%m-%d", &tm);
 576         if (k && *k == 0) {
 577                 tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
 578                 goto finish;
 579         }
 580
 581         tm = copy;
 582         k = strptime(t, "%H:%M:%S", &tm);
 583         if (k && *k == 0)
 584                 goto finish;
 585
 586         tm = copy;
 587         k = strptime(t, "%H:%M", &tm);
 588         if (k && *k == 0) {
 589                 tm.tm_sec = 0;
 590                 goto finish;
 591         }
 592
 593         return -EINVAL;
 594
 595 finish:
 596         x = mktime(&tm);
 597         if (x == (time_t) -1)
 598                 return -EINVAL;
 599
 600         if (weekday >= 0 && tm.tm_wday != weekday)
 601                 return -EINVAL;
 602
 603         ret = (usec_t) x * USEC_PER_SEC;
 604
 605         ret += plus;
 606         if (ret > minus)
 607                 ret -= minus;
 608         else
 609                 ret = 0;
 610
 611         *usec = ret;
 612
 613         return 0;
 614 }
 615
 616 int parse_sec(const char *t, usec_t *usec) {
 617         static const struct {
 618                 const char *suffix;
 619                 usec_t usec;
 620         } table[] = {
 621                 { "seconds", USEC_PER_SEC },
 622                 { "second", USEC_PER_SEC },
 623                 { "sec", USEC_PER_SEC },
 624                 { "s", USEC_PER_SEC },
 625                 { "minutes", USEC_PER_MINUTE },
 626                 { "minute", USEC_PER_MINUTE },
 627                 { "min", USEC_PER_MINUTE },
 628                 { "months", USEC_PER_MONTH },
 629                 { "month", USEC_PER_MONTH },
 630                 { "msec", USEC_PER_MSEC },
 631                 { "ms", USEC_PER_MSEC },
 632                 { "m", USEC_PER_MINUTE },
 633                 { "hours", USEC_PER_HOUR },
 634                 { "hour", USEC_PER_HOUR },
 635                 { "hr", USEC_PER_HOUR },
 636                 { "h", USEC_PER_HOUR },
 637                 { "days", USEC_PER_DAY },
 638                 { "day", USEC_PER_DAY },
 639                 { "d", USEC_PER_DAY },
 640                 { "weeks", USEC_PER_WEEK },
 641                 { "week", USEC_PER_WEEK },
 642                 { "w", USEC_PER_WEEK },
 643                 { "years", USEC_PER_YEAR },
 644                 { "year", USEC_PER_YEAR },
 645                 { "y", USEC_PER_YEAR },
 646                 { "usec", 1ULL },
 647                 { "us", 1ULL },
 648                 { "", USEC_PER_SEC }, /* default is sec */
 649         };
 650
 651         const char *p, *s;
 652         usec_t r = 0;
 653         bool something = false;
 654
 655         assert(t);
 656         assert(usec);
 657
 658         p = t;
 659
 660         p += strspn(p, WHITESPACE);
 661         s = startswith(p, "infinity");
 662         if (s) {
 663                 s += strspn(s, WHITESPACE);
 664                 if (*s != 0)
 665                         return -EINVAL;
 666
 667                 *usec = USEC_INFINITY;
 668                 return 0;
 669         }
 670
 671         for (;;) {
 672                 long long l, z = 0;
 673                 char *e;
 674                 unsigned i, n = 0;
 675
 676                 p += strspn(p, WHITESPACE);
 677
 678                 if (*p == 0) {
 679                         if (!something)
 680                                 return -EINVAL;
 681
 682                         break;
 683                 }
 684
 685                 errno = 0;
 686                 l = strtoll(p, &e, 10);
 687
 688                 if (errno > 0)
 689                         return -errno;
 690
 691                 if (l < 0)
 692                         return -ERANGE;
 693
 694                 if (*e == '.') {
 695                         char *b = e + 1;
 696
 697                         errno = 0;
 698                         z = strtoll(b, &e, 10);
 699                         if (errno > 0)
 700                                 return -errno;
 701
 702                         if (z < 0)
 703                                 return -ERANGE;
 704
 705                         if (e == b)
 706                                 return -EINVAL;
 707
 708                         n = e - b;
 709
 710                 } else if (e == p)
 711                         return -EINVAL;
 712
 713                 e += strspn(e, WHITESPACE);
 714
 715                 for (i = 0; i < ELEMENTSOF(table); i++)
 716                         if (startswith(e, table[i].suffix)) {
 717                                 usec_t k = (usec_t) z * table[i].usec;
 718
 719                                 for (; n > 0; n--)
 720                                         k /= 10;
 721
 722                                 r += (usec_t) l * table[i].usec + k;
 723                                 p = e + strlen(table[i].suffix);
 724
 725                                 something = true;
 726                                 break;
 727                         }
 728
 729                 if (i >= ELEMENTSOF(table))
 730                         return -EINVAL;
 731
 732         }
 733
 734         *usec = r;
 735
 736         return 0;
 737 }
 738
 739 int parse_nsec(const char *t, nsec_t *nsec) {
 740         static const struct {
 741                 const char *suffix;
 742                 nsec_t nsec;
 743         } table[] = {
 744                 { "seconds", NSEC_PER_SEC },
 745                 { "second", NSEC_PER_SEC },
 746                 { "sec", NSEC_PER_SEC },
 747                 { "s", NSEC_PER_SEC },
 748                 { "minutes", NSEC_PER_MINUTE },
 749                 { "minute", NSEC_PER_MINUTE },
 750                 { "min", NSEC_PER_MINUTE },
 751                 { "months", NSEC_PER_MONTH },
 752                 { "month", NSEC_PER_MONTH },
 753                 { "msec", NSEC_PER_MSEC },
 754                 { "ms", NSEC_PER_MSEC },
 755                 { "m", NSEC_PER_MINUTE },
 756                 { "hours", NSEC_PER_HOUR },
 757                 { "hour", NSEC_PER_HOUR },
 758                 { "hr", NSEC_PER_HOUR },
 759                 { "h", NSEC_PER_HOUR },
 760                 { "days", NSEC_PER_DAY },
 761                 { "day", NSEC_PER_DAY },
 762                 { "d", NSEC_PER_DAY },
 763                 { "weeks", NSEC_PER_WEEK },
 764                 { "week", NSEC_PER_WEEK },
 765                 { "w", NSEC_PER_WEEK },
 766                 { "years", NSEC_PER_YEAR },
 767                 { "year", NSEC_PER_YEAR },
 768                 { "y", NSEC_PER_YEAR },
 769                 { "usec", NSEC_PER_USEC },
 770                 { "us", NSEC_PER_USEC },
 771                 { "nsec", 1ULL },
 772                 { "ns", 1ULL },
 773                 { "", 1ULL }, /* default is nsec */
 774         };
 775
 776         const char *p, *s;
 777         nsec_t r = 0;
 778         bool something = false;
 779
 780         assert(t);
 781         assert(nsec);
 782
 783         p = t;
 784
 785         p += strspn(p, WHITESPACE);
 786         s = startswith(p, "infinity");
 787         if (s) {
 788                 s += strspn(s, WHITESPACE);
 789                 if (*s != 0)
 790                         return -EINVAL;
 791
 792                 *nsec = NSEC_INFINITY;
 793                 return 0;
 794         }
 795
 796         for (;;) {
 797                 long long l, z = 0;
 798                 char *e;
 799                 unsigned i, n = 0;
 800
 801                 p += strspn(p, WHITESPACE);
 802
 803                 if (*p == 0) {
 804                         if (!something)
 805                                 return -EINVAL;
 806
 807                         break;
 808                 }
 809
 810                 errno = 0;
 811                 l = strtoll(p, &e, 10);
 812
 813                 if (errno > 0)
 814                         return -errno;
 815
 816                 if (l < 0)
 817                         return -ERANGE;
 818
 819                 if (*e == '.') {
 820                         char *b = e + 1;
 821
 822                         errno = 0;
 823                         z = strtoll(b, &e, 10);
 824                         if (errno > 0)
 825                                 return -errno;
 826
 827                         if (z < 0)
 828                                 return -ERANGE;
 829
 830                         if (e == b)
 831                                 return -EINVAL;
 832
 833                         n = e - b;
 834
 835                 } else if (e == p)
 836                         return -EINVAL;
 837
 838                 e += strspn(e, WHITESPACE);
 839
 840                 for (i = 0; i < ELEMENTSOF(table); i++)
 841                         if (startswith(e, table[i].suffix)) {
 842                                 nsec_t k = (nsec_t) z * table[i].nsec;
 843
 844                                 for (; n > 0; n--)
 845                                         k /= 10;
 846
 847                                 r += (nsec_t) l * table[i].nsec + k;
 848                                 p = e + strlen(table[i].suffix);
 849
 850                                 something = true;
 851                                 break;
 852                         }
 853
 854                 if (i >= ELEMENTSOF(table))
 855                         return -EINVAL;
 856
 857         }
 858
 859         *nsec = r;
 860
 861         return 0;
 862 }
 863
 864 bool ntp_synced(void) {
 865         struct timex txc = {};
 866
 867         if (adjtimex(&txc) < 0)
 868                 return false;
 869
 870         if (txc.status & STA_UNSYNC)
 871                 return false;
 872
 873         return true;
 874 }
 875
 876 int get_timezones(char ***ret) {
 877         _cleanup_fclose_ FILE *f = NULL;
 878         _cleanup_strv_free_ char **zones = NULL;
 879         size_t n_zones = 0, n_allocated = 0;
 880
 881         assert(ret);
 882
 883         zones = strv_new("UTC", NULL);
 884         if (!zones)
 885                 return -ENOMEM;
 886
 887         n_allocated = 2;
 888         n_zones = 1;
 889
 890         f = fopen("/usr/share/zoneinfo/zone.tab", "re");
 891         if (f) {
 892                 char l[LINE_MAX];
 893
 894                 FOREACH_LINE(l, f, return -errno) {
 895                         char *p, *w;
 896                         size_t k;
 897
 898                         p = strstrip(l);
 899
 900                         if (isempty(p) || *p == '#')
 901                                 continue;
 902
 903                         /* Skip over country code */
 904                         p += strcspn(p, WHITESPACE);
 905                         p += strspn(p, WHITESPACE);
 906
 907                         /* Skip over coordinates */
 908                         p += strcspn(p, WHITESPACE);
 909                         p += strspn(p, WHITESPACE);
 910
 911                         /* Found timezone name */
 912                         k = strcspn(p, WHITESPACE);
 913                         if (k <= 0)
 914                                 continue;
 915
 916                         w = strndup(p, k);
 917                         if (!w)
 918                                 return -ENOMEM;
 919
 920                         if (!GREEDY_REALLOC(zones, n_allocated, n_zones + 2)) {
 921                                 free(w);
 922                                 return -ENOMEM;
 923                         }
 924
 925                         zones[n_zones++] = w;
 926                         zones[n_zones] = NULL;
 927                 }
 928
 929                 strv_sort(zones);
 930
 931         } else if (errno != ENOENT)
 932                 return -errno;
 933
 934         *ret = zones;
 935         zones = NULL;
 936
 937         return 0;
 938 }
 939
 940 bool timezone_is_valid(const char *name) {
 941         bool slash = false;
 942         const char *p, *t;
 943         struct stat st;
 944
 945         if (!name || *name == 0 || *name == '/')
 946                 return false;
 947
 948         for (p = name; *p; p++) {
 949                 if (!(*p >= '0' && *p <= '9') &&
 950                     !(*p >= 'a' && *p <= 'z') &&
 951                     !(*p >= 'A' && *p <= 'Z') &&
 952                     !(*p == '-' || *p == '_' || *p == '+' || *p == '/'))
 953                         return false;
 954
 955                 if (*p == '/') {
 956
 957                         if (slash)
 958                                 return false;
 959
 960                         slash = true;
 961                 } else
 962                         slash = false;
 963         }
 964
 965         if (slash)
 966                 return false;
 967
 968         t = strjoina("/usr/share/zoneinfo/", name);
 969         if (stat(t, &st) < 0)
 970                 return false;
 971
 972         if (!S_ISREG(st.st_mode))
 973                 return false;
 974
 975         return true;
 976 }
 977
 978 clockid_t clock_boottime_or_monotonic(void) {
 979         static clockid_t clock = -1;
 980         int fd;
 981
 982         if (clock != -1)
 983                 return clock;
 984
 985         fd = timerfd_create(CLOCK_BOOTTIME, TFD_NONBLOCK|TFD_CLOEXEC);
 986         if (fd < 0)
 987                 clock = CLOCK_MONOTONIC;
 988         else {
 989                 safe_close(fd);
 990                 clock = CLOCK_BOOTTIME;
 991         }
 992
 993         return clock;
 994 }