src/interfaces/timedated/timedated.c

   1 /*
   2  * Copyright (c) 2014 Ian Sutton <ian@kremlin.cc>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include <unistd.h>
  18 #include <limits.h>
  19 #include <signal.h>
  20
  21 #include <sys/types.h>
  22 #include <sys/time.h>
  23 #include <sys/stat.h>
  24 #include <errno.h>
  25 #include <time.h>
  26 #include <string.h>
  27 #include <tzfile.h>
  28
  29 #include <glib/gprintf.h>
  30 #include <glib-unix.h>
  31 #include <glib/gstdio.h>
  32 #include <polkit/polkit.h>
  33
  34 #include "timedated-gen.h"
  35 #include "timedated.h"
  36
  37 #include "../../util.h"
  38
  39 #define TZNAME_MAX PATH_MAX
  40
  41 GPtrArray *timedated_freeable;
  42 Timedate1 *timedated_interf;
  43
  44 GMainLoop *timedated_loop;
  45
  46 guint bus_descriptor;
  47 gboolean dbus_interface_exported; /* reliable because of gdbus operational guarantees */
  48
  49 const gchar *OS_LOCALTIME       = "/etc/localtime";      /* current timezone file */
  50 const gchar *OS_TIMEZONE_PATH   = "/usr/share/zoneinfo"; /* path to system timezone files */
  51
  52 struct timezone_checksum_pair {
  53
  54     gchar *path;
  55     gchar *sum;
  56     gboolean posix;
  57     gboolean right;
  58 };
  59
  60 static struct timezone_checksum_pair tz_table[5000];
  61
  62 /* --- begin method/property/dbus signal code --- */
  63
  64 static gboolean
  65 on_handle_set_time(Timedate1 *td1_passed_interf,
  66                    GDBusMethodInvocation *invoc,
  67                    const gchar *greet,
  68                    gpointer data) {
  69
  70     GVariant *params;
  71     gint64 proposed_time, cur_time;
  72     const gchar *bus_name;
  73     gboolean policykit_auth;
  74     check_auth_result is_authed;
  75     gboolean relative; /* relative if passed time_t is meant to be added to current time */
  76     struct timespec *new_time;
  77
  78     params = g_dbus_method_invocation_get_parameters(invoc);
  79     g_variant_get(params, "(xbb)", &proposed_time, &relative, &policykit_auth);
  80     bus_name = g_dbus_method_invocation_get_sender(invoc);
  81
  82     is_authed = polkit_try_auth(bus_name, "org.freedesktop.timedate1.set-time", policykit_auth);
  83
  84     switch(is_authed) {
  85
  86         case AUTHORIZED_NATIVELY:
  87         case AUTHORIZED_BY_PROMPT:
  88             break;
  89
  90         case UNAUTHORIZED_NATIVELY:
  91         case UNAUTHORIZED_FAILED_PROMPT:
  92             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EACCES", "Insufficient permissions to set system time.");
  93             return FALSE;
  94
  95         case ERROR_BADBUS:
  96             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EFAULT", "Provided bus name is invalid.");
  97             return FALSE;
  98
  99         case ERROR_BADACTION:
 100             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EFAULT", "Provided action ID is invalid.");
 101             return FALSE;
 102
 103         case ERROR_GENERIC:
 104         default:
 105             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.ECANCELED", "Failed to set system time for unknown reasons.");
 106             return FALSE;
 107     }
 108
 109     if(!proposed_time) {
 110
 111         timedate1_complete_set_time(td1_passed_interf, invoc);
 112         return TRUE;
 113
 114     } else if(relative) {
 115
 116         cur_time = g_get_real_time();
 117
 118         if(proposed_time < 0 && cur_time + proposed_time > cur_time) {
 119
 120             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EINVAL", "Resultant time out of bounds.");
 121             return FALSE;
 122
 123         } else if(proposed_time > 0 && cur_time + proposed_time < cur_time) {
 124
 125             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EINVAL", "Resultant time out of bounds.");
 126             return FALSE;
 127         }
 128
 129         new_time = mktimespec(proposed_time);
 130
 131         if(!clock_settime(CLOCK_REALTIME, new_time)) {
 132
 133             timedate1_complete_set_time(td1_passed_interf, invoc);
 134             return TRUE;
 135
 136         } else {
 137
 138             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.ECANCELED", "Failed to set system time for unknown reasons.");
 139             return FALSE;
 140         }
 141
 142     } else if(proposed_time > 0) {
 143
 144
 145         new_time = mktimespec(proposed_time);
 146
 147         if(!clock_settime(CLOCK_REALTIME, new_time)) {
 148
 149             timedate1_complete_set_time(td1_passed_interf, invoc);
 150             return TRUE;
 151
 152         } else {
 153
 154             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.ECANCELED", "Failed to set system time for unknown reasons.");
 155             return FALSE;
 156         }
 157
 158     } else {
 159
 160         g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EINVAL", "Resultant time out of bounds.");
 161         return FALSE;
 162     }
 163 }
 164
 165 static gboolean
 166 on_handle_set_timezone(Timedate1 *td1_passed_interf,
 167                    GDBusMethodInvocation *invoc,
 168                    const gchar *greet,
 169                    gpointer data) {
 170
 171     GVariant *params;
 172     gchar *proposed_tz;
 173     const gchar *bus_name;
 174     gboolean policykit_auth;
 175     check_auth_result is_authed;
 176
 177     gchar *tz_target_path;
 178     struct stat *statbuf;
 179     extern int errno;
 180
 181     params = g_dbus_method_invocation_get_parameters(invoc);
 182     g_variant_get(params, "(sb)", &proposed_tz, &policykit_auth);
 183     bus_name = g_dbus_method_invocation_get_sender(invoc);
 184
 185     is_authed = polkit_try_auth(bus_name, "org.freedesktop.timedate1.set-timezone", policykit_auth);
 186
 187     switch(is_authed) {
 188
 189         case AUTHORIZED_NATIVELY:
 190         case AUTHORIZED_BY_PROMPT:
 191             break;
 192
 193         case UNAUTHORIZED_NATIVELY:
 194         case UNAUTHORIZED_FAILED_PROMPT:
 195             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EACCES", "Insufficient permissions to set timezone.");
 196             return FALSE;
 197
 198         case ERROR_BADBUS:
 199             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EFAULT", "Provided bus name is invalid.");
 200             return FALSE;
 201
 202         case ERROR_BADACTION:
 203             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EFAULT", "Provided action ID is invalid.");
 204             return FALSE;
 205
 206         case ERROR_GENERIC:
 207         default:
 208             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.ECANCELED", "Failed to set timezone for unknown reasons.");
 209             return FALSE;
 210     }
 211
 212     statbuf        = (struct stat*) calloc(1, sizeof(struct stat));
 213     tz_target_path = (gchar *) calloc(1, TZNAME_MAX);
 214
 215     g_ptr_array_add(timedated_freeable, statbuf);
 216     g_ptr_array_add(timedated_freeable, tz_target_path);
 217
 218     strlcat(tz_target_path, TZDIR, TZNAME_MAX);
 219     strlcat(tz_target_path, "/", TZNAME_MAX);
 220     strlcat(tz_target_path, proposed_tz, TZNAME_MAX);
 221
 222     if(strstr(tz_target_path, "../")) {
 223
 224         g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EBADF", "Provided timezone is invalid.");
 225         return FALSE;
 226     }
 227
 228     if(!statbuf)
 229         return FALSE;
 230
 231     if(lstat(tz_target_path, statbuf)) {
 232
 233         switch(errno) {
 234
 235             case ENOENT:
 236                 g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.ENOENT", "Specified timezone does not exist.");
 237                 break;
 238
 239             default:
 240                 g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EBADF", "Specified timezone is invalid.");
 241                 break;
 242         }
 243
 244         return FALSE;
 245     }
 246
 247     if(!S_ISREG(statbuf->st_mode)) {
 248
 249         g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EBADF", "Specified path is of an inappropriate type.");
 250         return FALSE;
 251     }
 252
 253     memset(statbuf, 0, sizeof statbuf);
 254
 255     if(!lstat(TZDEFAULT, statbuf))
 256         if(remove(TZDEFAULT))
 257             return FALSE;
 258
 259     if(symlink(tz_target_path, TZDEFAULT))
 260         return FALSE;
 261
 262
 263     timedate1_complete_set_timezone(td1_passed_interf, invoc);
 264
 265     return TRUE;
 266 }
 267
 268 static gboolean
 269 on_handle_set_local_rtc(Timedate1 *td1_passed_interf,
 270                         GDBusMethodInvocation *invoc,
 271                         const gchar *greet,
 272                         gpointer data) {
 273
 274     g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.ENODEV", "Unix RTC must be in UTC.");
 275     return TRUE;
 276 }
 277
 278 static gboolean
 279 on_handle_set_ntp(Timedate1 *td1_passed_interf,
 280                   GDBusMethodInvocation *invoc,
 281                   const gchar *greet,
 282                   gpointer data) {
 283
 284     GVariant *params;
 285     const gchar *bus_name;
 286     gboolean policykit_auth;
 287     check_auth_result is_authed;
 288
 289                                             /* revert to rcctl when 5.7 rolls around */
 290     gint ntpd_notrunning, ntpd_notenabled; /* this logic flip is due to rcctl returning 0 on success,
 291                                              * in this case an error means ntpd is not running or not enabled */
 292     gboolean proposed_ntpstate;
 293     GError *sh_errors;
 294
 295     extern int errno;
 296
 297     params = g_dbus_method_invocation_get_parameters(invoc);
 298     g_variant_get(params, "(bb)", &proposed_ntpstate, &policykit_auth);
 299     bus_name = g_dbus_method_invocation_get_sender(invoc);
 300
 301     is_authed = polkit_try_auth(bus_name, "org.freedesktop.timedate1.set-ntp", policykit_auth);
 302
 303     switch(is_authed) {
 304
 305         case AUTHORIZED_NATIVELY:
 306         case AUTHORIZED_BY_PROMPT:
 307             break;
 308
 309         case UNAUTHORIZED_NATIVELY:
 310         case UNAUTHORIZED_FAILED_PROMPT:
 311             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EACCES", "Insufficient permissions to toggle the NTP daemon.");
 312             return FALSE;
 313
 314         case ERROR_BADBUS:
 315             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EFAULT", "Provided bus name is invalid.");
 316             return FALSE;
 317
 318         case ERROR_BADACTION:
 319             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EFAULT", "Provided action ID is invalid.");
 320             return FALSE;
 321
 322         case ERROR_GENERIC:
 323         default:
 324             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.ECANCELED", "Failed to toggle the NTP daemon for unknown reasons.");
 325             return FALSE;
 326     }
 327
 328     ntpd_notrunning = 0;   /* GLib does not bother asserting the passed return value int to zero */
 329     ntpd_notenabled = 0;   /* if the program's exit status is also zero, hence this decl.        */
 330
 331     if((ntpd_notrunning = system("/etc/rc.d/ntpd check > /dev/null 2>&1")) == -1)
 332         return FALSE;
 333
 334     if((ntpd_notenabled = system("/etc/rc.d/ntpd status > /dev/null 2>&1")) == -1)
 335         return FALSE;
 336
 337     if(proposed_ntpstate) {
 338
 339         if(ntpd_notrunning)
 340             system("/etc/rc.d/ntpd -f start > /dev/null 2>&1");
 341
 342         if(ntpd_notenabled)
 343             system("/etc/rc.d/ntpd enable > /dev/null 2>&1");
 344
 345     } else {
 346
 347         if(!ntpd_notrunning)
 348             system("/etc/rc.d/ntpd stop > /dev/null 2>&1");
 349
 350         if(!ntpd_notenabled)
 351             system("/etc/rc.d/ntpd disable > /dev/null 2>&1");
 352     }
 353
 354     timedate1_complete_set_ntp(td1_passed_interf, invoc);
 355
 356     return TRUE;
 357 }
 358 /* NOTE: you should be using gobject->set_property() for these ! */
 359 const gchar *
 360 our_get_timezone() {
 361
 362     GStatBuf *stat_zoneinfo;
 363     gchar *find_cmd, *readlink_path, *ret, *argvp, *hash_to_match;
 364     gint argcp;
 365     GError *err;
 366     struct timezone_checksum_pair tmp;
 367
 368     find_cmd      = (gchar *)    g_malloc0(2048);
 369     stat_zoneinfo = (GStatBuf *) g_malloc0(8192);
 370     err           = (GError *)   g_malloc0(2048);
 371
 372     if(g_stat(OS_LOCALTIME, stat_zoneinfo)) {
 373
 374         g_printf("could not read from %s! please symlink or copy a timezone file from %s to %s!\n", OS_LOCALTIME, OS_TIMEZONE_PATH, OS_LOCALTIME);
 375         ret = NULL;
 376
 377     } else if(g_file_test(OS_LOCALTIME, G_FILE_TEST_IS_SYMLINK)) {
 378
 379         readlink_path = g_file_read_link(OS_LOCALTIME, &err);
 380
 381         gchar *split[2] = { readlink_path, "" };
 382         tmp = parse_timezone_path(split);
 383
 384         ret = tmp.path;
 385
 386         if(readlink_path)
 387             g_free(readlink_path);
 388
 389     } else {
 390
 391         g_printf("%s is not a symlink! attempting to match checksums in %s...\n", OS_LOCALTIME, OS_TIMEZONE_PATH);
 392         hash_to_match = get_file_sha256(OS_LOCALTIME);
 393
 394         /* ret = lookup_hash(hash_to_match); */
 395         return FALSE; /* TODO fix me for real */
 396
 397         if(hash_to_match)
 398             g_free(hash_to_match);
 399     }
 400
 401     return ret;
 402 }
 403
 404 /* Unix time is in UTC. */
 405 gboolean
 406 our_get_local_rtc() {
 407
 408     return FALSE;
 409 }
 410
 411 gboolean
 412 our_get_can_ntp() {
 413
 414     /* ntpd is part of the default install */
 415
 416     return TRUE;
 417 }
 418
 419 gboolean
 420 our_get_ntp() {
 421
 422     int system_ret;
 423
 424     system_ret = system("/etc/rc.d/ntpd check > /dev/null 2>&1");
 425
 426     if(system_ret)
 427         return FALSE;
 428
 429     return TRUE;
 430 }
 431
 432 /* undocumented feature present in systemd */
 433 gboolean
 434 our_get_ntpsynchronized() {
 435
 436     gboolean ntp;
 437     ntp = our_get_ntp();
 438
 439     return ntp;
 440 }
 441
 442 /* undocumented feature present in systemd */
 443 guint64
 444 our_get_time_usec() {
 445
 446     guint64 ret = 0;
 447
 448     return ret;
 449 }
 450
 451 /* undocumented feature present in systemd */
 452 guint64
 453 our_get_rtc_time_usec() {
 454
 455     guint64 ret = 0;
 456
 457     return ret;
 458 }
 459
 460 /* --- end method/property/dbus signal code, begin bus/name handlers --- */
 461
 462 static void timedated_on_bus_acquired(GDBusConnection *conn,
 463                                       const gchar *name,
 464                                       gpointer user_data) {
 465
 466     g_printf("got bus/name, exporting %s's interface...\n", name);
 467
 468     timedated_interf = timedate1_skeleton_new();
 469
 470     /* attach function pointers to generated struct's method handlers */
 471     g_signal_connect(timedated_interf, "handle-set-time",     G_CALLBACK(on_handle_set_time),     NULL);
 472     g_signal_connect(timedated_interf, "handle-set-timezone", G_CALLBACK(on_handle_set_timezone), NULL);
 473     g_signal_connect(timedated_interf, "handle-set-local-rtc", G_CALLBACK(on_handle_set_local_rtc), NULL);
 474     g_signal_connect(timedated_interf, "handle-set-ntp",      G_CALLBACK(on_handle_set_ntp),      NULL);
 475
 476     /* set our properties before export */
 477
 478     timedate1_set_timezone(timedated_interf, our_get_timezone());
 479     timedate1_set_local_rtc(timedated_interf, our_get_local_rtc());
 480     timedate1_set_can_ntp(timedated_interf, our_get_can_ntp());
 481     timedate1_set_ntp(timedated_interf, our_get_ntp());
 482     timedate1_set_ntpsynchronized(timedated_interf, our_get_ntpsynchronized());
 483     timedate1_set_time_usec(timedated_interf, our_get_time_usec());
 484     timedate1_set_rtctime_usec(timedated_interf, our_get_rtc_time_usec());
 485
 486     /* WIP
 487
 488     timedated_interf->get_timezone        = our_get_timezone();
 489     timedated_interf->get_local_rtc       = our_get_local_rtc();
 490     timedated_interf->get_can_ntp         = our_get_can_ntp();
 491     timedated_interf->get_ntp             = our_get_ntp();
 492     timedated_interf->get_ntpsynchronized = our_get_ntpsynchronized();
 493     timedated_interf->get_time_usec       = our_get_time_usec();
 494     timedated_interf->get_rtctime_usec    = our_get_rtc_time_usec(); */
 495
 496     if(!g_dbus_interface_skeleton_export(G_DBUS_INTERFACE_SKELETON(timedated_interf),
 497                                          conn,
 498                                          "/org/freedesktop/timedate1",
 499                                          NULL)) {
 500
 501         g_printf("failed to export %s's interface!\n", name);
 502         timedated_mem_clean();
 503
 504     } else {
 505
 506         dbus_interface_exported = TRUE;
 507         g_printf("exported %s's interface on the system bus...\n", name);
 508     }
 509 }
 510
 511 static void timedated_on_name_acquired(GDBusConnection *conn,
 512                                        const gchar *name,
 513                                        gpointer user_data) {
 514
 515    g_printf("success!\n");
 516 }
 517
 518 static void timedated_on_name_lost(GDBusConnection *conn,
 519                                    const gchar *name,
 520                                    gpointer user_data) {
 521
 522     if(!conn) {
 523
 524         g_printf("failed to connect to the system bus while trying to acquire name '%s': either dbus-daemon isn't running or we don't have permission to push names and/or their interfaces to it.\n", name);
 525         timedated_mem_clean();
 526     }
 527
 528     g_print("lost name %s, exiting...\n", name);
 529
 530     timedated_mem_clean();
 531 }
 532
 533 /* --- end bus/name handlers, begin misc unix functions --- */
 534
 535 /* safe call to clean and then exit
 536  * this stops our GMainLoop safely before letting main() return */
 537 void timedated_mem_clean() {
 538
 539     g_printf("exiting...\n");
 540
 541     if(dbus_interface_exported)
 542         g_dbus_interface_skeleton_unexport(G_DBUS_INTERFACE_SKELETON(timedated_interf));
 543
 544      if(g_main_loop_is_running(timedated_loop))
 545         g_main_loop_quit(timedated_loop);
 546
 547 }
 548
 549 /* wrapper for glib's unix signal handling; called only once if terminating signal is raised against us */
 550 gboolean unix_sig_terminate_handler(gpointer data) {
 551
 552     g_printf("caught SIGINT/HUP/TERM, exiting\n");
 553
 554     timedated_mem_clean();
 555     return G_SOURCE_REMOVE;
 556 }
 557
 558 void set_signal_handlers() {
 559
 560     /* we don't care about its descriptor, we never need to unregister these */
 561     g_unix_signal_add(SIGINT,  unix_sig_terminate_handler, NULL);
 562     g_unix_signal_add(SIGHUP,  unix_sig_terminate_handler, NULL);
 563     g_unix_signal_add(SIGTERM, unix_sig_terminate_handler, NULL);
 564 }
 565
 566 int main() {
 567
 568     set_signal_handlers();
 569
 570     /*if(!build_lookup_table())
 571         return 1; */
 572
 573     timedated_loop = g_main_loop_new(NULL, TRUE);
 574     timedated_freeable = g_ptr_array_new();
 575
 576      bus_descriptor = g_bus_own_name(G_BUS_TYPE_SYSTEM,
 577                                     "org.freedesktop.timedate1",
 578                                     G_BUS_NAME_OWNER_FLAGS_NONE,
 579                                     timedated_on_bus_acquired,
 580                                     timedated_on_name_acquired,
 581                                     timedated_on_name_lost,
 582                                     NULL,
 583                                     NULL);
 584
 585     g_main_loop_run(timedated_loop);
 586     /* runs until single g_main_loop_quit() call is raised inside <interface>_mem_clean() */
 587     g_main_loop_unref(timedated_loop);
 588
 589     /* guaranteed unownable */
 590     g_bus_unown_name(bus_descriptor);
 591
 592     /* at this point no operations can occur with our data, it is safe to free it + its container */
 593     g_ptr_array_free(timedated_freeable, TRUE);
 594
 595     return 0;
 596 }
 597
 598 static struct timezone_checksum_pair parse_timezone_path(gchar **pair) {
 599
 600     gchar *prefix_pattern, *right_prefix_pattern, *posix_prefix_pattern, *lean_path;
 601     GRegex *prefix, *posix, *right;
 602     GError *err = NULL;
 603     struct timezone_checksum_pair ret = { NULL, NULL, FALSE, FALSE };
 604
 605     if(!pair[0])
 606         return ret;
 607
 608     prefix_pattern = (gchar *) g_malloc0(4096);
 609     right_prefix_pattern = (gchar *) g_malloc0(4096);
 610     posix_prefix_pattern = (gchar *) g_malloc0(4096);
 611
 612     g_sprintf(prefix_pattern, "%s/", OS_TIMEZONE_PATH);
 613     g_sprintf(posix_prefix_pattern, "%s/posix/", OS_TIMEZONE_PATH);
 614     g_sprintf(right_prefix_pattern, "%s/right/", OS_TIMEZONE_PATH);
 615
 616     prefix = g_regex_new(prefix_pattern, 0, 0, &err);
 617     posix  = g_regex_new(posix_prefix_pattern, 0, 0, &err);
 618     right  = g_regex_new(right_prefix_pattern, 0, 0, &err);
 619
 620     if(g_regex_match_full(posix, pair[0], -1, 0, G_REGEX_MATCH_NOTEMPTY, NULL, NULL)) {
 621
 622         ret.posix = TRUE;
 623         lean_path = g_regex_replace_literal(posix, pair[0], -1, 0, "", G_REGEX_MATCH_NOTEMPTY, NULL);
 624
 625     } else if(g_regex_match_full(right, pair[0], -1, 0, G_REGEX_MATCH_NOTEMPTY, NULL, NULL)) {
 626
 627        ret.right = TRUE;
 628        lean_path = g_regex_replace_literal(right, pair[0], -1, 0, "", G_REGEX_MATCH_NOTEMPTY, NULL);
 629
 630     } else
 631         lean_path = g_regex_replace_literal(prefix, pair[0], -1, 0, "", G_REGEX_MATCH_NOTEMPTY, NULL);
 632
 633     ret.path = lean_path;
 634
 635     ret.sum = g_malloc0(256);
 636     g_strlcpy(ret.sum, pair[1], 66);
 637
 638     g_regex_unref(prefix);
 639     g_regex_unref(right);
 640     g_regex_unref(posix);
 641
 642     return ret;
 643 }
 644
 645 /* TODO need to deconstruct tz_table on exit
 646 static gboolean build_lookup_table() {
 647
 648         gchar *find_cmd, **map_pairs, *find_output, *path_buf, *sum_buf, **entry_buf;
 649         GError *err;
 650         gboolean ret;
 651         gint i;
 652
 653         i   = 0;
 654         err = NULL;
 655         ret = TRUE;
 656
 657         find_cmd    = (gchar *) g_malloc0(4096);
 658         find_output = (gchar *) g_malloc0(1000000);
 659
 660         g_sprintf(find_cmd, "/bin/sh -c \"find %s -type f -exec cksum -a sha256 {} \\; | sed -E 's/SHA256 \\(//g' | sed -E 's/\\) = /=/g'\"", OS_TIMEZONE_PATH);
 661
 662         if(!g_spawn_command_line_sync(find_cmd, &find_output, NULL, NULL, &err)) {
 663
 664             g_printf("error running `%s`\n", find_cmd);
 665             ret = FALSE;
 666         }
 667
 668         map_pairs = g_strsplit(find_output, "\n", INT_MAX);
 669
 670         while(map_pairs[i] && (entry_buf = g_strsplit(map_pairs[i], "=", INT_MAX))) {
 671
 672             tz_table[i] = parse_timezone_path(entry_buf);
 673
 674             g_strfreev(entry_buf);
 675             i++;
 676         }
 677
 678         g_free(find_output);
 679         g_free(find_cmd);
 680         g_free(map_pairs);
 681
 682         return ret;
 683 }
 684
 685 static gchar *lookup_hash(gchar *hash) {
 686
 687     gint i = 0;
 688
 689     while(tz_table[i].sum)
 690         if(!g_strcmp0(tz_table[i].sum, hash))
 691             return tz_table[i].path;
 692         else
 693             i++;
 694
 695     return NULL;
 696 }*/
 697
 698 /* takes number of microseconds since epoch and returns a
 699  * ptr to a timespec suitable to be passed to clock_settime(3)
 700  */
 701 static struct timespec* mktimespec(gint64 us) {
 702
 703     long nanoseconds;
 704     time_t seconds;
 705
 706     gint64 div_buf_remainder, div_buf_s, div_buf_ns;
 707     struct timespec *ret;
 708
 709     div_buf_s         = (us / 1000000); /* us / 10^6 = s */
 710     div_buf_remainder = (us % 1000000); /* fraction of second lost from prev. line */
 711     div_buf_ns        = div_buf_remainder * 1000; /* us * 10^3 = ns */
 712
 713     seconds     = (time_t) div_buf_s; /* porting note: most systems use 32 bit time, adjust accordingly */
 714     nanoseconds = (long)   div_buf_ns;
 715
 716     ret = (struct timespec *) calloc(1, sizeof(struct timespec));
 717
 718     ret->tv_sec  = seconds;
 719     ret->tv_nsec = nanoseconds;
 720
 721     g_ptr_array_add(timedated_freeable, ret);
 722
 723     return ret;
 724 }