src/timeserver.c

   1 /*
   2  *
   3  *  Connection Manager
   4  *
   5  *  Copyright (C) 2007-2013  Intel Corporation. All rights reserved.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License version 2 as
   9  *  published by the Free Software Foundation.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <errno.h>
  27
  28 #include <glib.h>
  29 #include <stdlib.h>
  30 #include <gweb/gresolv.h>
  31 #include <netdb.h>
  32 #include <sys/time.h>
  33
  34 #include "connman.h"
  35
  36 #define TS_RECHECK_INTERVAL     7200
  37
  38 static struct connman_service *ts_service;
  39 static GSList *timeservers_list = NULL;
  40 static GSList *ts_list = NULL;
  41 static char *ts_current = NULL;
  42 static int ts_recheck_id = 0;
  43 static int ts_backoff_id = 0;
  44 static bool ts_is_synced = false;
  45
  46 static GResolv *resolv = NULL;
  47 static int resolv_id = 0;
  48
  49 static void sync_next(void);
  50
  51 static void resolv_debug(const char *str, void *data)
  52 {
  53         connman_info("%s: %s\n", (const char *) data, str);
  54 }
  55
  56 static void ntp_callback(bool success, void *user_data)
  57 {
  58         dbus_uint64_t timestamp;
  59         struct timeval tv;
  60
  61         DBG("success %d", success);
  62
  63         __connman_timeserver_set_synced(success);
  64         if (!success) {
  65                 sync_next();
  66                 return;
  67         }
  68
  69         if (gettimeofday(&tv, NULL) < 0) {
  70                 connman_warn("Failed to get current time");
  71         }
  72
  73         timestamp = tv.tv_sec;
  74         connman_dbus_property_changed_basic(
  75                                         CONNMAN_MANAGER_PATH,
  76                                         CONNMAN_CLOCK_INTERFACE, "Time",
  77                                         DBUS_TYPE_UINT64, &timestamp);
  78 }
  79
  80 static void save_timeservers(char **servers)
  81 {
  82         GKeyFile *keyfile;
  83         int cnt;
  84
  85         keyfile = __connman_storage_load_global();
  86         if (!keyfile)
  87                 keyfile = g_key_file_new();
  88
  89         for (cnt = 0; servers && servers[cnt]; cnt++);
  90
  91         g_key_file_set_string_list(keyfile, "global", "Timeservers",
  92                            (const gchar **)servers, cnt);
  93
  94         __connman_storage_save_global(keyfile);
  95
  96         g_key_file_free(keyfile);
  97 }
  98
  99 static char **load_timeservers(void)
 100 {
 101         GKeyFile *keyfile;
 102         char **servers = NULL;
 103
 104         keyfile = __connman_storage_load_global();
 105         if (!keyfile)
 106                 return NULL;
 107
 108         servers = g_key_file_get_string_list(keyfile, "global",
 109                                                 "Timeservers", NULL, NULL);
 110
 111         g_key_file_free(keyfile);
 112
 113         return servers;
 114 }
 115
 116 static void resolv_result(GResolvResultStatus status, char **results,
 117                                 gpointer user_data)
 118 {
 119         int i;
 120
 121         DBG("status %d", status);
 122
 123         if (status == G_RESOLV_RESULT_STATUS_SUCCESS) {
 124                 if (results) {
 125                         /* prepend the results in reverse order */
 126
 127                         for (i = 0; results[i]; i++)
 128                                 /* count */;
 129                         i--;
 130
 131                         for (; i >= 0; i--) {
 132                                 DBG("result[%d]: %s", i, results[i]);
 133
 134                                 ts_list = __connman_timeserver_add_list(
 135                                         ts_list, results[i]);
 136                         }
 137                 }
 138         }
 139
 140         sync_next();
 141 }
 142
 143 /*
 144  * Once the timeserver list (timeserver_list) is created, we start
 145  * querying the servers one by one. If resolving fails on one of them,
 146  * we move to the next one. The user can enter either an IP address or
 147  * a URL for the timeserver. We only resolve the URLs. Once we have an
 148  * IP for the NTP server, we start querying it for time corrections.
 149  */
 150 static void timeserver_sync_start(void)
 151 {
 152         GSList *list;
 153
 154         for (list = timeservers_list; list; list = list->next) {
 155                 char *timeserver = list->data;
 156
 157                 ts_list = g_slist_prepend(ts_list, g_strdup(timeserver));
 158         }
 159         ts_list = g_slist_reverse(ts_list);
 160
 161         sync_next();
 162 }
 163
 164 static gboolean timeserver_sync_restart(gpointer user_data)
 165 {
 166         timeserver_sync_start();
 167         ts_backoff_id = 0;
 168
 169         return FALSE;
 170 }
 171
 172 /*
 173  * Select the next time server from the working list (ts_list) because
 174  * for some reason the first time server in the list didn't work. If
 175  * none of the server did work we start over with the first server
 176  * with a backoff.
 177  */
 178 static void sync_next(void)
 179 {
 180         if (ts_current) {
 181                 g_free(ts_current);
 182                 ts_current = NULL;
 183         }
 184
 185         __connman_ntp_stop();
 186
 187         while (ts_list) {
 188                 ts_current = ts_list->data;
 189                 ts_list = g_slist_delete_link(ts_list, ts_list);
 190
 191                 /* if it's an IP, directly query it. */
 192                 if (connman_inet_check_ipaddress(ts_current) > 0) {
 193                         DBG("Using timeserver %s", ts_current);
 194                         __connman_ntp_start(ts_current, ntp_callback, NULL);
 195                         return;
 196                 }
 197
 198                 DBG("Resolving timeserver %s", ts_current);
 199                 resolv_id = g_resolv_lookup_hostname(resolv, ts_current,
 200                                                 resolv_result, NULL);
 201                 return;
 202         }
 203
 204         DBG("No timeserver could be used, restart probing in 5 seconds");
 205         ts_backoff_id = g_timeout_add_seconds(5, timeserver_sync_restart, NULL);
 206 }
 207
 208 GSList *__connman_timeserver_add_list(GSList *server_list,
 209                 const char *timeserver)
 210 {
 211         GSList *list = server_list;
 212
 213         if (!timeserver)
 214                 return server_list;
 215
 216         while (list) {
 217                 char *existing_server = list->data;
 218                 if (strcmp(timeserver, existing_server) == 0)
 219                         return server_list;
 220                 list = g_slist_next(list);
 221         }
 222         return g_slist_prepend(server_list, g_strdup(timeserver));
 223 }
 224
 225 /*
 226  * __connman_timeserver_get_all function creates the timeserver
 227  * list which will be used to determine NTP server for time corrections.
 228  * The service settings take priority over the global timeservers.
 229  */
 230 GSList *__connman_timeserver_get_all(struct connman_service *service)
 231 {
 232         GSList *list = NULL;
 233         struct connman_network *network;
 234         char **timeservers;
 235         char **service_ts;
 236         char **service_ts_config;
 237         const char *service_gw;
 238         char **fallback_ts;
 239         int index, i;
 240
 241         if (__connman_clock_timeupdates() == TIME_UPDATES_MANUAL)
 242                 return NULL;
 243
 244         service_ts_config = connman_service_get_timeservers_config(service);
 245
 246         /* First add Service Timeservers.Configuration to the list */
 247         for (i = 0; service_ts_config && service_ts_config[i];
 248                         i++)
 249                 list = __connman_timeserver_add_list(list,
 250                                 service_ts_config[i]);
 251
 252         service_ts = connman_service_get_timeservers(service);
 253
 254         /* Then add Service Timeservers via DHCP to the list */
 255         for (i = 0; service_ts && service_ts[i]; i++)
 256                 list = __connman_timeserver_add_list(list, service_ts[i]);
 257
 258         /*
 259          * Then add Service Gateway to the list, if UseGatewaysAsTimeservers
 260          * configuration option is set to true.
 261          */
 262         if (connman_setting_get_bool("UseGatewaysAsTimeservers")) {
 263                 network = __connman_service_get_network(service);
 264                 if (network) {
 265                         index = connman_network_get_index(network);
 266                         service_gw = __connman_ipconfig_get_gateway_from_index(index,
 267                                 CONNMAN_IPCONFIG_TYPE_ALL);
 268
 269                         if (service_gw)
 270                                 list = __connman_timeserver_add_list(list, service_gw);
 271                 }
 272         }
 273
 274         /* Then add Global Timeservers to the list */
 275         timeservers = load_timeservers();
 276
 277         for (i = 0; timeservers && timeservers[i]; i++)
 278                 list = __connman_timeserver_add_list(list, timeservers[i]);
 279
 280         g_strfreev(timeservers);
 281
 282         fallback_ts = connman_setting_get_string_list("FallbackTimeservers");
 283
 284         /* Lastly add the fallback servers */
 285         for (i = 0; fallback_ts && fallback_ts[i]; i++)
 286                 list = __connman_timeserver_add_list(list, fallback_ts[i]);
 287
 288         return g_slist_reverse(list);
 289 }
 290
 291 static gboolean ts_recheck(gpointer user_data)
 292 {
 293         struct connman_service *service;
 294         GSList *ts;
 295
 296         ts = __connman_timeserver_get_all(connman_service_get_default());
 297
 298         if (!ts) {
 299                 DBG("timeservers disabled");
 300
 301                 return TRUE;
 302         }
 303
 304         if (g_strcmp0(ts_current, ts->data) != 0) {
 305                 DBG("current %s preferred %s", ts_current, (char *)ts->data);
 306
 307                 g_slist_free_full(ts, g_free);
 308
 309                 service = connman_service_get_default();
 310                 __connman_timeserver_sync(service);
 311
 312                 return FALSE;
 313         }
 314
 315         DBG("");
 316
 317         g_slist_free_full(ts, g_free);
 318
 319         return TRUE;
 320 }
 321
 322 static void ts_recheck_disable(void)
 323 {
 324         if (ts_recheck_id == 0)
 325                 return;
 326
 327         g_source_remove(ts_recheck_id);
 328         ts_recheck_id = 0;
 329
 330         if (ts_backoff_id) {
 331                 g_source_remove(ts_backoff_id);
 332                 ts_backoff_id = 0;
 333         }
 334
 335         if (ts_current) {
 336                 g_free(ts_current);
 337                 ts_current = NULL;
 338         }
 339 }
 340
 341 static void ts_recheck_enable(void)
 342 {
 343         if (ts_recheck_id > 0)
 344                 return;
 345
 346         ts_recheck_id = g_timeout_add_seconds(TS_RECHECK_INTERVAL, ts_recheck,
 347                         NULL);
 348 }
 349
 350 static void ts_reset(struct connman_service *service)
 351 {
 352         char **nameservers;
 353         int i;
 354
 355         if (!resolv)
 356                 return;
 357
 358         __connman_timeserver_set_synced(false);
 359
 360         /*
 361          * Before we start creating the new timeserver list we must stop
 362          * any ongoing ntp query and server resolution.
 363          */
 364
 365         __connman_ntp_stop();
 366
 367         ts_recheck_disable();
 368
 369         if (resolv_id > 0)
 370                 g_resolv_cancel_lookup(resolv, resolv_id);
 371
 372         g_resolv_flush_nameservers(resolv);
 373
 374         nameservers = connman_service_get_nameservers(service);
 375         if (nameservers) {
 376                 for (i = 0; nameservers[i]; i++)
 377                         g_resolv_add_nameserver(resolv, nameservers[i], 53, 0);
 378
 379                 g_strfreev(nameservers);
 380         }
 381
 382         g_slist_free_full(timeservers_list, g_free);
 383
 384         timeservers_list = __connman_timeserver_get_all(service);
 385
 386         __connman_service_timeserver_changed(service, timeservers_list);
 387
 388         if (!timeservers_list) {
 389                 DBG("No timeservers set.");
 390                 return;
 391         }
 392
 393         ts_recheck_enable();
 394
 395         ts_service = service;
 396         timeserver_sync_start();
 397 }
 398
 399 void __connman_timeserver_sync(struct connman_service *service)
 400 {
 401         if (!service || ts_service == service)
 402                 return;
 403
 404         ts_reset(service);
 405 }
 406
 407 void __connman_timeserver_conf_update(struct connman_service *service)
 408 {
 409         if (!service || (ts_service && ts_service != service))
 410                 return;
 411
 412         ts_reset(service);
 413 }
 414
 415
 416 bool __connman_timeserver_is_synced(void)
 417 {
 418         return ts_is_synced;
 419 }
 420
 421 void __connman_timeserver_set_synced(bool status)
 422 {
 423         dbus_bool_t is_synced;
 424
 425         if (ts_is_synced == status)
 426                 return;
 427
 428         ts_is_synced = status;
 429         is_synced = status;
 430         connman_dbus_property_changed_basic(CONNMAN_MANAGER_PATH,
 431                                 CONNMAN_CLOCK_INTERFACE, "TimeserverSynced",
 432                                 DBUS_TYPE_BOOLEAN, &is_synced);
 433 }
 434
 435 static int timeserver_start(struct connman_service *service)
 436 {
 437         char **nameservers;
 438         int i;
 439
 440         DBG("service %p", service);
 441
 442         i = __connman_service_get_index(service);
 443         if (i < 0)
 444                 return -EINVAL;
 445
 446         nameservers = connman_service_get_nameservers(service);
 447
 448         /* Stop an already ongoing resolution, if there is one */
 449         if (resolv && resolv_id > 0)
 450                 g_resolv_cancel_lookup(resolv, resolv_id);
 451
 452         /* get rid of the old resolver */
 453         if (resolv) {
 454                 g_resolv_unref(resolv);
 455                 resolv = NULL;
 456         }
 457
 458         resolv = g_resolv_new(i);
 459         if (!resolv) {
 460                 g_strfreev(nameservers);
 461                 return -ENOMEM;
 462         }
 463
 464         if (getenv("CONNMAN_RESOLV_DEBUG"))
 465                 g_resolv_set_debug(resolv, resolv_debug, "RESOLV");
 466
 467         if (nameservers) {
 468                 for (i = 0; nameservers[i]; i++)
 469                         g_resolv_add_nameserver(resolv, nameservers[i], 53, 0);
 470
 471                 g_strfreev(nameservers);
 472         }
 473
 474         __connman_timeserver_sync(service);
 475
 476         return 0;
 477 }
 478
 479 static void timeserver_stop(void)
 480 {
 481         DBG(" ");
 482
 483         ts_service = NULL;
 484
 485         if (resolv) {
 486                 g_resolv_unref(resolv);
 487                 resolv = NULL;
 488         }
 489
 490         g_slist_free_full(timeservers_list, g_free);
 491         timeservers_list = NULL;
 492
 493         g_slist_free_full(ts_list, g_free);
 494         ts_list = NULL;
 495
 496         __connman_ntp_stop();
 497
 498         ts_recheck_disable();
 499 }
 500
 501 int __connman_timeserver_system_set(char **servers)
 502 {
 503         struct connman_service *service;
 504
 505         save_timeservers(servers);
 506
 507         service = connman_service_get_default();
 508         if (service)
 509                 ts_reset(service);
 510
 511         return 0;
 512 }
 513
 514 char **__connman_timeserver_system_get()
 515 {
 516         char **servers;
 517
 518         servers = load_timeservers();
 519         return servers;
 520 }
 521
 522 static void default_changed(struct connman_service *default_service)
 523 {
 524         if (default_service)
 525                 timeserver_start(default_service);
 526         else
 527                 timeserver_stop();
 528 }
 529
 530 static const struct connman_notifier timeserver_notifier = {
 531         .name                   = "timeserver",
 532         .default_changed        = default_changed,
 533 };
 534
 535 int __connman_timeserver_init(void)
 536 {
 537         DBG("");
 538
 539         connman_notifier_register(&timeserver_notifier);
 540
 541         return 0;
 542 }
 543
 544 void __connman_timeserver_cleanup(void)
 545 {
 546         DBG("");
 547
 548         connman_notifier_unregister(&timeserver_notifier);
 549 }