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 <time.h>
  24 #include <string.h>
  25
  26 #include <glib/gprintf.h>
  27 #include <glib-unix.h>
  28 #include <glib/gstdio.h>
  29 #include <polkit/polkit.h>
  30
  31 #include "timedated-gen.h"
  32 #include "timedated.h"
  33
  34 #include "../../util.h"
  35
  36 GPtrArray *timedated_freeable;
  37 Timedate1 *timedated_interf;
  38
  39 GMainLoop *timedated_loop;
  40
  41 guint bus_descriptor;
  42 gboolean dbus_interface_exported; /* reliable because of gdbus operational guarantees */
  43
  44 const gchar *OS_LOCALTIME       = "/etc/localtime";      /* current timezone file */
  45 const gchar *OS_TIMEZONE_PATH   = "/usr/share/zoneinfo"; /* path to system timezone files */
  46
  47 struct timezone_checksum_pair {
  48
  49     gchar *path;
  50     gchar *sum;
  51     gboolean posix;
  52     gboolean right;
  53 };
  54
  55 static struct timezone_checksum_pair tz_table[5000];
  56
  57 /* --- begin method/property/dbus signal code --- */
  58
  59 static gboolean
  60 on_handle_set_time(Timedate1 *td1_passed_interf,
  61                    GDBusMethodInvocation *invoc,
  62                    const gchar *greet,
  63                    gpointer data) {
  64
  65     GVariant *params;
  66     gint64 proposed_time, cur_time;
  67     const gchar *bus_name;
  68     gboolean policykit_auth;
  69     check_auth_result is_authed;
  70     gboolean relative; /* relative if passed time_t is meant to be added to current time */
  71     struct timespec *new_time;
  72
  73     params = g_dbus_method_invocation_get_parameters(invoc);
  74     g_variant_get(params, "(xbb)", &proposed_time, &relative, &policykit_auth);
  75     bus_name = g_dbus_method_invocation_get_sender(invoc);
  76
  77     is_authed = polkit_try_auth(bus_name, "org.freedesktop.timedate1.set-time", policykit_auth);
  78
  79     switch(is_authed) {
  80
  81         case AUTHORIZED_NATIVELY:
  82         case AUTHORIZED_BY_PROMPT:
  83             break;
  84
  85         case UNAUTHORIZED_NATIVELY:
  86         case UNAUTHORIZED_FAILED_PROMPT:
  87             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EACCES", "Insufficient permissions to set system time.");
  88             return FALSE;
  89
  90         case ERROR_BADBUS:
  91             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EFAULT", "Provided bus name is invalid.");
  92             return FALSE;
  93
  94         case ERROR_BADACTION:
  95             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EFAULT", "Provided action ID is invalid.");
  96             return FALSE;
  97
  98         case ERROR_GENERIC:
  99         default:
 100             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.ECANCELED", "Failed to set system time for unknown reasons.");
 101             return FALSE;
 102     }
 103
 104     if(!proposed_time) {
 105
 106         timedate1_complete_set_time(td1_passed_interf, invoc);
 107         return TRUE;
 108
 109     } else if(relative) {
 110
 111         new_time = (struct timespec *) g_malloc0(sizeof(struct timespec));
 112         cur_time = g_get_real_time();
 113
 114         if(proposed_time < 0 && cur_time + proposed_time > proposed_time) {
 115
 116             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EINVAL", "Resultant time out of bounds.");
 117             return FALSE;
 118
 119         } else if(cur_time + proposed_time < proposed_time) {
 120
 121             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EINVAL", "Resultant time out of bounds.");
 122             return FALSE;
 123         }
 124
 125         new_time = (struct timespec *) g_malloc0(sizeof(struct timespec));
 126         new_time->tv_sec = proposed_time;
 127         new_time->tv_nsec = 0;
 128         g_ptr_array_add(timedated_freeable, new_time);
 129
 130         if(!clock_settime(CLOCK_REALTIME, new_time)) {
 131
 132             timedate1_complete_set_time(td1_passed_interf, invoc);
 133             return TRUE;
 134
 135         } else {
 136
 137             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.ECANCELED", "Failed to set system time for unknown reasons.");
 138             return FALSE;
 139         }
 140
 141     } else if(proposed_time >= 0) {
 142
 143         new_time = (struct timespec *) g_malloc0(sizeof(struct timespec));
 144         new_time->tv_sec = proposed_time;
 145         new_time->tv_nsec = 0;
 146         g_ptr_array_add(timedated_freeable, new_time);
 147
 148         if(!clock_settime(CLOCK_REALTIME, new_time)) {
 149
 150             timedate1_complete_set_time(td1_passed_interf, invoc);
 151             return TRUE;
 152
 153         } else {
 154
 155             g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.ECANCELED", "Failed to set system time for unknown reasons.");
 156             return FALSE;
 157         }
 158
 159     } else {
 160
 161         g_dbus_method_invocation_return_dbus_error(invoc, "org.freedesktop.timedate1.Error.EINVAL", "Resultant time out of bounds.");
 162         return FALSE;
 163     }
 164 }
 165
 166 static gboolean
 167 on_handle_set_timezone(Timedate1 *td1_passed_interf,
 168                    GDBusMethodInvocation *invoc,
 169                    const gchar *greet,
 170                    gpointer data) {
 171     return FALSE;
 172 }
 173
 174 static gboolean
 175 on_handle_set_local_rtc(Timedate1 *td1_passed_interf,
 176                         GDBusMethodInvocation *invoc,
 177                         const gchar *greet,
 178                         gpointer data) {
 179     return FALSE;
 180 }
 181
 182 static gboolean
 183 on_handle_set_ntp(Timedate1 *td1_passed_interf,
 184                   GDBusMethodInvocation *invoc,
 185                   const gchar *greet,
 186                   gpointer data) {
 187     return FALSE;
 188 }
 189
 190 const gchar *
 191 our_get_timezone() {
 192
 193     GStatBuf *stat_zoneinfo;
 194     gchar *find_cmd, *readlink_path, *ret, *argvp, *hash_to_match;
 195     gint argcp;
 196     GError *err;
 197     struct timezone_checksum_pair tmp;
 198
 199     find_cmd      = (gchar *)    g_malloc0(2048);
 200     stat_zoneinfo = (GStatBuf *) g_malloc0(8192);
 201     err           = (GError *)   g_malloc0(2048);
 202
 203     if(g_stat(OS_LOCALTIME, stat_zoneinfo)) {
 204
 205         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);
 206         ret = NULL;
 207
 208     } else if(g_file_test(OS_LOCALTIME, G_FILE_TEST_IS_SYMLINK)) {
 209
 210         readlink_path = g_file_read_link(OS_LOCALTIME, &err);
 211
 212         gchar *split[2] = { readlink_path, "" };
 213         tmp = parse_timezone_path(split);
 214
 215         ret = tmp.path;
 216
 217         if(readlink_path)
 218             g_free(readlink_path);
 219
 220     } else {
 221
 222         g_printf("%s is not a symlink! attempting to match checksums in %s...\n", OS_LOCALTIME, OS_TIMEZONE_PATH);
 223         hash_to_match = get_file_sha256(OS_LOCALTIME);
 224
 225         ret = lookup_hash(hash_to_match);
 226
 227         if(hash_to_match)
 228             g_free(hash_to_match);
 229     }
 230
 231     return ret;
 232 }
 233
 234 gboolean
 235 our_get_local_rtc() {
 236
 237     gboolean ret = FALSE;
 238
 239     return ret;
 240 }
 241
 242 gboolean
 243 our_get_can_ntp() {
 244
 245     const gboolean ret = FALSE;
 246
 247     return ret;
 248 }
 249
 250 gboolean
 251 our_get_ntp() {
 252
 253     const gboolean ret = FALSE;
 254
 255     return ret;
 256 }
 257
 258 gboolean
 259 our_get_ntpsynchronized() {
 260
 261     const gboolean ret = FALSE;
 262
 263     return ret;
 264 }
 265
 266 guint64
 267 our_get_time_usec() {
 268
 269     guint64 ret = 0;
 270
 271     return ret;
 272 }
 273
 274 guint64
 275 our_get_rtc_time_usec() {
 276
 277     guint64 ret = 0;
 278
 279     return ret;
 280 }
 281
 282 /* --- end method/property/dbus signal code, begin bus/name handlers --- */
 283
 284 static void timedated_on_bus_acquired(GDBusConnection *conn,
 285                                       const gchar *name,
 286                                       gpointer user_data) {
 287
 288     g_printf("got bus/name, exporting %s's interface...\n", name);
 289
 290     timedated_interf = timedate1_skeleton_new();
 291
 292     /* attach function pointers to generated struct's method handlers */
 293     g_signal_connect(timedated_interf, "handle-set-time",     G_CALLBACK(on_handle_set_time),     NULL);
 294     g_signal_connect(timedated_interf, "handle-set-timezone", G_CALLBACK(on_handle_set_timezone), NULL);
 295     g_signal_connect(timedated_interf, "handle-set-local-rtc", G_CALLBACK(on_handle_set_local_rtc), NULL);
 296     g_signal_connect(timedated_interf, "handle-set-ntp",      G_CALLBACK(on_handle_set_ntp),      NULL);
 297
 298     /* set our properties before export */
 299     timedate1_set_timezone(timedated_interf, our_get_timezone());
 300     timedate1_set_local_rtc(timedated_interf, our_get_local_rtc());
 301     timedate1_set_can_ntp(timedated_interf, our_get_can_ntp());
 302     timedate1_set_ntp(timedated_interf, our_get_ntp());
 303     timedate1_set_ntpsynchronized(timedated_interf, our_get_ntpsynchronized());
 304     timedate1_set_time_usec(timedated_interf, our_get_time_usec());
 305     timedate1_set_rtctime_usec(timedated_interf, our_get_rtc_time_usec());
 306
 307     if(!g_dbus_interface_skeleton_export(G_DBUS_INTERFACE_SKELETON(timedated_interf),
 308                                          conn,
 309                                          "/org/freedesktop/timedate1",
 310                                          NULL)) {
 311
 312         g_printf("failed to export %s's interface!\n", name);
 313         timedated_mem_clean();
 314
 315     } else {
 316
 317         dbus_interface_exported = TRUE;
 318         g_printf("exported %s's interface on the system bus...\n", name);
 319     }
 320 }
 321
 322 static void timedated_on_name_acquired(GDBusConnection *conn,
 323                                        const gchar *name,
 324                                        gpointer user_data) {
 325
 326    g_printf("success!\n");
 327 }
 328
 329 static void timedated_on_name_lost(GDBusConnection *conn,
 330                                    const gchar *name,
 331                                    gpointer user_data) {
 332
 333     if(!conn) {
 334
 335         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);
 336         timedated_mem_clean();
 337     }
 338
 339     g_print("lost name %s, exiting...\n", name);
 340
 341     timedated_mem_clean();
 342 }
 343
 344 /* --- end bus/name handlers, begin misc unix functions --- */
 345
 346 /* safe call to clean and then exit
 347  * this stops our GMainLoop safely before letting main() return */
 348 void timedated_mem_clean() {
 349
 350     g_printf("exiting...\n");
 351
 352     if(dbus_interface_exported)
 353         g_dbus_interface_skeleton_unexport(G_DBUS_INTERFACE_SKELETON(timedated_interf));
 354
 355      if(g_main_loop_is_running(timedated_loop))
 356         g_main_loop_quit(timedated_loop);
 357
 358 }
 359
 360 /* wrapper for glib's unix signal handling; called only once if terminating signal is raised against us */
 361 gboolean unix_sig_terminate_handler(gpointer data) {
 362
 363     g_printf("caught SIGINT/HUP/TERM, exiting\n");
 364
 365     timedated_mem_clean();
 366     return G_SOURCE_REMOVE;
 367 }
 368
 369 void set_signal_handlers() {
 370
 371     /* we don't care about its descriptor, we never need to unregister these */
 372     g_unix_signal_add(SIGINT,  unix_sig_terminate_handler, NULL);
 373     g_unix_signal_add(SIGHUP,  unix_sig_terminate_handler, NULL);
 374     g_unix_signal_add(SIGTERM, unix_sig_terminate_handler, NULL);
 375 }
 376
 377 int main() {
 378
 379     set_signal_handlers();
 380
 381     if(!build_lookup_table())
 382         return 1;
 383
 384     timedated_loop = g_main_loop_new(NULL, TRUE);
 385     timedated_freeable = g_ptr_array_new();
 386
 387      bus_descriptor = g_bus_own_name(G_BUS_TYPE_SYSTEM,
 388                                     "org.freedesktop.timedate1",
 389                                     G_BUS_NAME_OWNER_FLAGS_NONE,
 390                                     timedated_on_bus_acquired,
 391                                     timedated_on_name_acquired,
 392                                     timedated_on_name_lost,
 393                                     NULL,
 394                                     NULL);
 395
 396     g_main_loop_run(timedated_loop);
 397     /* runs until single g_main_loop_quit() call is raised inside <interface>_mem_clean() */
 398     g_main_loop_unref(timedated_loop);
 399
 400     /* guaranteed unownable */
 401     g_bus_unown_name(bus_descriptor);
 402
 403     /* at this point no operations can occur with our data, it is safe to free it + its container */
 404     g_ptr_array_free(timedated_freeable, TRUE);
 405
 406     return 0;
 407 }
 408
 409 static struct timezone_checksum_pair parse_timezone_path(gchar **pair) {
 410
 411     gchar *prefix_pattern, *right_prefix_pattern, *posix_prefix_pattern, *lean_path;
 412     GRegex *prefix, *posix, *right;
 413     GError *err = NULL;
 414     struct timezone_checksum_pair ret = { NULL, NULL, FALSE, FALSE };
 415
 416     if(!pair[0])
 417         return ret;
 418
 419     prefix_pattern = (gchar *) g_malloc0(4096);
 420     right_prefix_pattern = (gchar *) g_malloc0(4096);
 421     posix_prefix_pattern = (gchar *) g_malloc0(4096);
 422
 423     g_sprintf(prefix_pattern, "%s/", OS_TIMEZONE_PATH);
 424     g_sprintf(posix_prefix_pattern, "%s/posix/", OS_TIMEZONE_PATH);
 425     g_sprintf(right_prefix_pattern, "%s/right/", OS_TIMEZONE_PATH);
 426
 427     prefix = g_regex_new(prefix_pattern, 0, 0, &err);
 428     posix  = g_regex_new(posix_prefix_pattern, 0, 0, &err);
 429     right  = g_regex_new(right_prefix_pattern, 0, 0, &err);
 430
 431     if(g_regex_match_full(posix, pair[0], -1, 0, G_REGEX_MATCH_NOTEMPTY, NULL, NULL)) {
 432
 433         ret.posix = TRUE;
 434         lean_path = g_regex_replace_literal(posix, pair[0], -1, 0, "", G_REGEX_MATCH_NOTEMPTY, NULL);
 435
 436     } else if(g_regex_match_full(right, pair[0], -1, 0, G_REGEX_MATCH_NOTEMPTY, NULL, NULL)) {
 437
 438        ret.right = TRUE;
 439        lean_path = g_regex_replace_literal(right, pair[0], -1, 0, "", G_REGEX_MATCH_NOTEMPTY, NULL);
 440
 441     } else
 442         lean_path = g_regex_replace_literal(prefix, pair[0], -1, 0, "", G_REGEX_MATCH_NOTEMPTY, NULL);
 443
 444     ret.path = lean_path;
 445
 446     ret.sum = g_malloc0(256);
 447     g_strlcpy(ret.sum, pair[1], 66);
 448
 449     g_regex_unref(prefix);
 450     g_regex_unref(right);
 451     g_regex_unref(posix);
 452
 453     return ret;
 454 }
 455
 456 /* TODO need to deconstruct tz_table on exit */
 457 static gboolean build_lookup_table() {
 458
 459         gchar *find_cmd, **map_pairs, *find_output, *path_buf, *sum_buf, **entry_buf;
 460         GError *err;
 461         gboolean ret;
 462         gint i;
 463
 464         i   = 0;
 465         err = NULL;
 466         ret = TRUE;
 467
 468         find_cmd    = (gchar *) g_malloc0(4096);
 469         find_output = (gchar *) g_malloc0(1000000);
 470
 471         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);
 472
 473         if(!g_spawn_command_line_sync(find_cmd, &find_output, NULL, NULL, &err)) {
 474
 475             g_printf("error running `%s`\n", find_cmd);
 476             ret = FALSE;
 477         }
 478
 479         map_pairs = g_strsplit(find_output, "\n", INT_MAX);
 480
 481         while(map_pairs[i] && (entry_buf = g_strsplit(map_pairs[i], "=", INT_MAX))) {
 482
 483             tz_table[i] = parse_timezone_path(entry_buf);
 484
 485             g_strfreev(entry_buf);
 486             i++;
 487         }
 488
 489         g_free(find_output);
 490         g_free(find_cmd);
 491         g_free(map_pairs);
 492
 493         return ret;
 494 }
 495
 496 static gchar *lookup_hash(gchar *hash) {
 497
 498     gint i = 0;
 499
 500     while(tz_table[i].sum)
 501         if(!g_strcmp0(tz_table[i].sum, hash))
 502             return tz_table[i].path;
 503         else
 504             i++;
 505
 506     return NULL;
 507 }