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     g_printf("%s\n", tz_target_path);
 223
 224     if(!statbuf)
 225         return FALSE;
 226
 227     if(lstat(tz_target_path, statbuf)) {
 228
 229         switch(errno) {
 230
 231             case ENOENT:
 232                 g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.ENOENT", "Specified timezone does not exist.");
 233                 break;
 234
 235             default:
 236                 g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EBADF", "Specified timezone is invalid.");
 237                 break;
 238         }
 239
 240         return FALSE;
 241     }
 242
 243     if(!S_ISREG(statbuf->st_mode)) {
 244
 245         g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EBADF", "Specified path is of an inappropriate type.");
 246         return FALSE;
 247     }
 248
 249     memset(statbuf, 0, sizeof statbuf);
 250
 251     if(!lstat(TZDEFAULT, statbuf))
 252         if(remove(TZDEFAULT))
 253             return FALSE;
 254
 255     if(symlink(tz_target_path, TZDEFAULT))
 256         return FALSE;
 257
 258
 259     timedate1_complete_set_timezone(td1_passed_interf, invoc);
 260
 261     return TRUE;
 262 }
 263
 264 static gboolean
 265 on_handle_set_local_rtc(Timedate1 *td1_passed_interf,
 266                         GDBusMethodInvocation *invoc,
 267                         const gchar *greet,
 268                         gpointer data) {
 269     return FALSE;
 270 }
 271
 272 static gboolean
 273 on_handle_set_ntp(Timedate1 *td1_passed_interf,
 274                   GDBusMethodInvocation *invoc,
 275                   const gchar *greet,
 276                   gpointer data) {
 277     return FALSE;
 278 }
 279
 280 const gchar *
 281 our_get_timezone() {
 282
 283     GStatBuf *stat_zoneinfo;
 284     gchar *find_cmd, *readlink_path, *ret, *argvp, *hash_to_match;
 285     gint argcp;
 286     GError *err;
 287     struct timezone_checksum_pair tmp;
 288
 289     find_cmd      = (gchar *)    g_malloc0(2048);
 290     stat_zoneinfo = (GStatBuf *) g_malloc0(8192);
 291     err           = (GError *)   g_malloc0(2048);
 292
 293     if(g_stat(OS_LOCALTIME, stat_zoneinfo)) {
 294
 295         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);
 296         ret = NULL;
 297
 298     } else if(g_file_test(OS_LOCALTIME, G_FILE_TEST_IS_SYMLINK)) {
 299
 300         readlink_path = g_file_read_link(OS_LOCALTIME, &err);
 301
 302         gchar *split[2] = { readlink_path, "" };
 303         tmp = parse_timezone_path(split);
 304
 305         ret = tmp.path;
 306
 307         if(readlink_path)
 308             g_free(readlink_path);
 309
 310     } else {
 311
 312         g_printf("%s is not a symlink! attempting to match checksums in %s...\n", OS_LOCALTIME, OS_TIMEZONE_PATH);
 313         hash_to_match = get_file_sha256(OS_LOCALTIME);
 314
 315         /* ret = lookup_hash(hash_to_match); */
 316         return FALSE; /* TODO fix me for real */
 317
 318         if(hash_to_match)
 319             g_free(hash_to_match);
 320     }
 321
 322
 323
 324     return ret;
 325 }
 326
 327 gboolean
 328 our_get_local_rtc() {
 329
 330     gboolean ret = FALSE;
 331
 332     return ret;
 333 }
 334
 335 gboolean
 336 our_get_can_ntp() {
 337
 338     const gboolean ret = FALSE;
 339
 340     return ret;
 341 }
 342
 343 gboolean
 344 our_get_ntp() {
 345
 346     const gboolean ret = FALSE;
 347
 348     return ret;
 349 }
 350
 351 gboolean
 352 our_get_ntpsynchronized() {
 353
 354     const gboolean ret = FALSE;
 355
 356     return ret;
 357 }
 358
 359 guint64
 360 our_get_time_usec() {
 361
 362     guint64 ret = 0;
 363
 364     return ret;
 365 }
 366
 367 guint64
 368 our_get_rtc_time_usec() {
 369
 370     guint64 ret = 0;
 371
 372     return ret;
 373 }
 374
 375 /* --- end method/property/dbus signal code, begin bus/name handlers --- */
 376
 377 static void timedated_on_bus_acquired(GDBusConnection *conn,
 378                                       const gchar *name,
 379                                       gpointer user_data) {
 380
 381     g_printf("got bus/name, exporting %s's interface...\n", name);
 382
 383     timedated_interf = timedate1_skeleton_new();
 384
 385     /* attach function pointers to generated struct's method handlers */
 386     g_signal_connect(timedated_interf, "handle-set-time",     G_CALLBACK(on_handle_set_time),     NULL);
 387     g_signal_connect(timedated_interf, "handle-set-timezone", G_CALLBACK(on_handle_set_timezone), NULL);
 388     g_signal_connect(timedated_interf, "handle-set-local-rtc", G_CALLBACK(on_handle_set_local_rtc), NULL);
 389     g_signal_connect(timedated_interf, "handle-set-ntp",      G_CALLBACK(on_handle_set_ntp),      NULL);
 390
 391     /* set our properties before export */
 392     timedate1_set_timezone(timedated_interf, our_get_timezone());
 393     timedate1_set_local_rtc(timedated_interf, our_get_local_rtc());
 394     timedate1_set_can_ntp(timedated_interf, our_get_can_ntp());
 395     timedate1_set_ntp(timedated_interf, our_get_ntp());
 396     timedate1_set_ntpsynchronized(timedated_interf, our_get_ntpsynchronized());
 397     timedate1_set_time_usec(timedated_interf, our_get_time_usec());
 398     timedate1_set_rtctime_usec(timedated_interf, our_get_rtc_time_usec());
 399
 400     if(!g_dbus_interface_skeleton_export(G_DBUS_INTERFACE_SKELETON(timedated_interf),
 401                                          conn,
 402                                          "/org/freedesktop/timedate1",
 403                                          NULL)) {
 404
 405         g_printf("failed to export %s's interface!\n", name);
 406         timedated_mem_clean();
 407
 408     } else {
 409
 410         dbus_interface_exported = TRUE;
 411         g_printf("exported %s's interface on the system bus...\n", name);
 412     }
 413 }
 414
 415 static void timedated_on_name_acquired(GDBusConnection *conn,
 416                                        const gchar *name,
 417                                        gpointer user_data) {
 418
 419    g_printf("success!\n");
 420 }
 421
 422 static void timedated_on_name_lost(GDBusConnection *conn,
 423                                    const gchar *name,
 424                                    gpointer user_data) {
 425
 426     if(!conn) {
 427
 428         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);
 429         timedated_mem_clean();
 430     }
 431
 432     g_print("lost name %s, exiting...\n", name);
 433
 434     timedated_mem_clean();
 435 }
 436
 437 /* --- end bus/name handlers, begin misc unix functions --- */
 438
 439 /* safe call to clean and then exit
 440  * this stops our GMainLoop safely before letting main() return */
 441 void timedated_mem_clean() {
 442
 443     g_printf("exiting...\n");
 444
 445     if(dbus_interface_exported)
 446         g_dbus_interface_skeleton_unexport(G_DBUS_INTERFACE_SKELETON(timedated_interf));
 447
 448      if(g_main_loop_is_running(timedated_loop))
 449         g_main_loop_quit(timedated_loop);
 450
 451 }
 452
 453 /* wrapper for glib's unix signal handling; called only once if terminating signal is raised against us */
 454 gboolean unix_sig_terminate_handler(gpointer data) {
 455
 456     g_printf("caught SIGINT/HUP/TERM, exiting\n");
 457
 458     timedated_mem_clean();
 459     return G_SOURCE_REMOVE;
 460 }
 461
 462 void set_signal_handlers() {
 463
 464     /* we don't care about its descriptor, we never need to unregister these */
 465     g_unix_signal_add(SIGINT,  unix_sig_terminate_handler, NULL);
 466     g_unix_signal_add(SIGHUP,  unix_sig_terminate_handler, NULL);
 467     g_unix_signal_add(SIGTERM, unix_sig_terminate_handler, NULL);
 468 }
 469
 470 int main() {
 471
 472     set_signal_handlers();
 473
 474     /*if(!build_lookup_table())
 475         return 1; */
 476
 477     timedated_loop = g_main_loop_new(NULL, TRUE);
 478     timedated_freeable = g_ptr_array_new();
 479
 480      bus_descriptor = g_bus_own_name(G_BUS_TYPE_SYSTEM,
 481                                     "org.freedesktop.timedate1",
 482                                     G_BUS_NAME_OWNER_FLAGS_NONE,
 483                                     timedated_on_bus_acquired,
 484                                     timedated_on_name_acquired,
 485                                     timedated_on_name_lost,
 486                                     NULL,
 487                                     NULL);
 488
 489     g_main_loop_run(timedated_loop);
 490     /* runs until single g_main_loop_quit() call is raised inside <interface>_mem_clean() */
 491     g_main_loop_unref(timedated_loop);
 492
 493     /* guaranteed unownable */
 494     g_bus_unown_name(bus_descriptor);
 495
 496     /* at this point no operations can occur with our data, it is safe to free it + its container */
 497     g_ptr_array_free(timedated_freeable, TRUE);
 498
 499     return 0;
 500 }
 501
 502 static struct timezone_checksum_pair parse_timezone_path(gchar **pair) {
 503
 504     gchar *prefix_pattern, *right_prefix_pattern, *posix_prefix_pattern, *lean_path;
 505     GRegex *prefix, *posix, *right;
 506     GError *err = NULL;
 507     struct timezone_checksum_pair ret = { NULL, NULL, FALSE, FALSE };
 508
 509     if(!pair[0])
 510         return ret;
 511
 512     prefix_pattern = (gchar *) g_malloc0(4096);
 513     right_prefix_pattern = (gchar *) g_malloc0(4096);
 514     posix_prefix_pattern = (gchar *) g_malloc0(4096);
 515
 516     g_sprintf(prefix_pattern, "%s/", OS_TIMEZONE_PATH);
 517     g_sprintf(posix_prefix_pattern, "%s/posix/", OS_TIMEZONE_PATH);
 518     g_sprintf(right_prefix_pattern, "%s/right/", OS_TIMEZONE_PATH);
 519
 520     prefix = g_regex_new(prefix_pattern, 0, 0, &err);
 521     posix  = g_regex_new(posix_prefix_pattern, 0, 0, &err);
 522     right  = g_regex_new(right_prefix_pattern, 0, 0, &err);
 523
 524     if(g_regex_match_full(posix, pair[0], -1, 0, G_REGEX_MATCH_NOTEMPTY, NULL, NULL)) {
 525
 526         ret.posix = TRUE;
 527         lean_path = g_regex_replace_literal(posix, pair[0], -1, 0, "", G_REGEX_MATCH_NOTEMPTY, NULL);
 528
 529     } else if(g_regex_match_full(right, pair[0], -1, 0, G_REGEX_MATCH_NOTEMPTY, NULL, NULL)) {
 530
 531        ret.right = TRUE;
 532        lean_path = g_regex_replace_literal(right, pair[0], -1, 0, "", G_REGEX_MATCH_NOTEMPTY, NULL);
 533
 534     } else
 535         lean_path = g_regex_replace_literal(prefix, pair[0], -1, 0, "", G_REGEX_MATCH_NOTEMPTY, NULL);
 536
 537     ret.path = lean_path;
 538
 539     ret.sum = g_malloc0(256);
 540     g_strlcpy(ret.sum, pair[1], 66);
 541
 542     g_regex_unref(prefix);
 543     g_regex_unref(right);
 544     g_regex_unref(posix);
 545
 546     return ret;
 547 }
 548
 549 /* TODO need to deconstruct tz_table on exit
 550 static gboolean build_lookup_table() {
 551
 552         gchar *find_cmd, **map_pairs, *find_output, *path_buf, *sum_buf, **entry_buf;
 553         GError *err;
 554         gboolean ret;
 555         gint i;
 556
 557         i   = 0;
 558         err = NULL;
 559         ret = TRUE;
 560
 561         find_cmd    = (gchar *) g_malloc0(4096);
 562         find_output = (gchar *) g_malloc0(1000000);
 563
 564         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);
 565
 566         if(!g_spawn_command_line_sync(find_cmd, &find_output, NULL, NULL, &err)) {
 567
 568             g_printf("error running `%s`\n", find_cmd);
 569             ret = FALSE;
 570         }
 571
 572         map_pairs = g_strsplit(find_output, "\n", INT_MAX);
 573
 574         while(map_pairs[i] && (entry_buf = g_strsplit(map_pairs[i], "=", INT_MAX))) {
 575
 576             tz_table[i] = parse_timezone_path(entry_buf);
 577
 578             g_strfreev(entry_buf);
 579             i++;
 580         }
 581
 582         g_free(find_output);
 583         g_free(find_cmd);
 584         g_free(map_pairs);
 585
 586         return ret;
 587 }
 588
 589 static gchar *lookup_hash(gchar *hash) {
 590
 591     gint i = 0;
 592
 593     while(tz_table[i].sum)
 594         if(!g_strcmp0(tz_table[i].sum, hash))
 595             return tz_table[i].path;
 596         else
 597             i++;
 598
 599     return NULL;
 600 }*/
 601
 602 /* takes number of microseconds since epoch and returns a
 603  * ptr to a timespec suitable to be passed to clock_settime(3)
 604  */
 605 static struct timespec* mktimespec(gint64 us) {
 606
 607     long nanoseconds;
 608     time_t seconds;
 609
 610     gint64 div_buf_remainder, div_buf_s, div_buf_ns;
 611     struct timespec *ret;
 612
 613     div_buf_s         = (us / 1000000); /* us / 10^6 = s */
 614     div_buf_remainder = (us % 1000000); /* fraction of second lost from prev. line */
 615     div_buf_ns        = div_buf_remainder * 1000; /* us * 10^3 = ns */
 616
 617     seconds     = (time_t) div_buf_s; /* porting note: most systems use 32 bit time, adjust accordingly */
 618     nanoseconds = (long)   div_buf_ns;
 619
 620     ret = (struct timespec *) calloc(1, sizeof(struct timespec));
 621
 622     ret->tv_sec  = seconds;
 623     ret->tv_nsec = nanoseconds;
 624
 625     g_ptr_array_add(timedated_freeable, ret);
 626
 627     return ret;
 628 }