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