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 #if defined TIZEN_EXT
 104         gchar *server = NULL;
 105
 106         server = g_strdup((gchar *)user_data);
 107         ts_list = g_slist_append(ts_list, server);
 108
 109         DBG("added server %s", server);
 110 #endif
 111
 112         DBG("status %d", status);
 113
 114         if (status == G_RESOLV_RESULT_STATUS_SUCCESS) {
 115                 if (results) {
 116                         /* prepend the results in reverse order */
 117
 118                         for (i = 0; results[i]; i++)
 119                                 /* count */;
 120                         i--;
 121
 122                         for (; i >= 0; i--) {
 123                                 DBG("result[%d]: %s", i, results[i]);
 124
 125                                 ts_list = __connman_timeserver_add_list(
 126                                         ts_list, results[i]);
 127                         }
 128                 }
 129         }
 130
 131         sync_next();
 132 }
 133
 134 /*
 135  * Once the timeserver list (timeserver_list) is created, we start
 136  * querying the servers one by one. If resolving fails on one of them,
 137  * we move to the next one. The user can enter either an IP address or
 138  * a URL for the timeserver. We only resolve the URLs. Once we have an
 139  * IP for the NTP server, we start querying it for time corrections.
 140  */
 141 static void timeserver_sync_start(void)
 142 {
 143         GSList *list;
 144
 145         for (list = timeservers_list; list; list = list->next) {
 146                 char *timeserver = list->data;
 147
 148                 ts_list = g_slist_prepend(ts_list, g_strdup(timeserver));
 149         }
 150         ts_list = g_slist_reverse(ts_list);
 151
 152         sync_next();
 153 }
 154
 155 static gboolean timeserver_sync_restart(gpointer user_data)
 156 {
 157         timeserver_sync_start();
 158         ts_backoff_id = 0;
 159
 160         return FALSE;
 161 }
 162
 163 /*
 164  * Select the next time server from the working list (ts_list) because
 165  * for some reason the first time server in the list didn't work. If
 166  * none of the server did work we start over with the first server
 167  * with a backoff.
 168  */
 169 static void sync_next(void)
 170 {
 171         if (ts_current) {
 172                 g_free(ts_current);
 173                 ts_current = NULL;
 174         }
 175
 176         __connman_ntp_stop();
 177
 178         while (ts_list) {
 179                 ts_current = ts_list->data;
 180                 ts_list = g_slist_delete_link(ts_list, ts_list);
 181
 182                 /* if it's an IP, directly query it. */
 183                 if (connman_inet_check_ipaddress(ts_current) > 0) {
 184                         DBG("Using timeserver %s", ts_current);
 185                         __connman_ntp_start(ts_current, ntp_callback, NULL);
 186                         return;
 187                 }
 188
 189                 DBG("Resolving timeserver %s", ts_current);
 190 #if defined TIZEN_EXT
 191                 resolv_id = g_resolv_lookup_hostname(resolv, ts_current,
 192                                                 resolv_result, ts_current);
 193 #else
 194                 resolv_id = g_resolv_lookup_hostname(resolv, ts_current,
 195                                                 resolv_result, NULL);
 196 #endif
 197                 return;
 198         }
 199
 200         DBG("No timeserver could be used, restart probing in 5 seconds");
 201         ts_backoff_id = g_timeout_add_seconds(5, timeserver_sync_restart, NULL);
 202 }
 203
 204 GSList *__connman_timeserver_add_list(GSList *server_list,
 205                 const char *timeserver)
 206 {
 207         GSList *list = server_list;
 208
 209         if (!timeserver)
 210                 return server_list;
 211
 212         while (list) {
 213                 char *existing_server = list->data;
 214                 if (strcmp(timeserver, existing_server) == 0)
 215                         return server_list;
 216                 list = g_slist_next(list);
 217         }
 218         return g_slist_prepend(server_list, g_strdup(timeserver));
 219 }
 220
 221 /*
 222  * __connman_timeserver_get_all function creates the timeserver
 223  * list which will be used to determine NTP server for time corrections.
 224  * The service settings take priority over the global timeservers.
 225  */
 226 GSList *__connman_timeserver_get_all(struct connman_service *service)
 227 {
 228         GSList *list = NULL;
 229         struct connman_network *network;
 230         char **timeservers;
 231         char **service_ts;
 232         char **service_ts_config;
 233         const char *service_gw;
 234         char **fallback_ts;
 235         int index, i;
 236
 237         if (__connman_clock_timeupdates() == TIME_UPDATES_MANUAL)
 238                 return NULL;
 239
 240         service_ts_config = connman_service_get_timeservers_config(service);
 241
 242         /* First add Service Timeservers.Configuration to the list */
 243         for (i = 0; service_ts_config && service_ts_config[i];
 244                         i++)
 245                 list = __connman_timeserver_add_list(list,
 246                                 service_ts_config[i]);
 247
 248         service_ts = connman_service_get_timeservers(service);
 249
 250         /* Then add Service Timeservers via DHCP to the list */
 251         for (i = 0; service_ts && service_ts[i]; i++)
 252                 list = __connman_timeserver_add_list(list, service_ts[i]);
 253
 254         /*
 255          * Then add Service Gateway to the list, if UseGatewaysAsTimeservers
 256          * configuration option is set to true.
 257          */
 258         if (connman_setting_get_bool("UseGatewaysAsTimeservers")) {
 259                 network = __connman_service_get_network(service);
 260                 if (network) {
 261                         index = connman_network_get_index(network);
 262                         service_gw = __connman_ipconfig_get_gateway_from_index(index,
 263                                 CONNMAN_IPCONFIG_TYPE_ALL);
 264
 265                         if (service_gw)
 266                                 list = __connman_timeserver_add_list(list, service_gw);
 267                 }
 268         }
 269
 270         /* Then add Global Timeservers to the list */
 271         timeservers = load_timeservers();
 272
 273         for (i = 0; timeservers && timeservers[i]; i++)
 274                 list = __connman_timeserver_add_list(list, timeservers[i]);
 275
 276         g_strfreev(timeservers);
 277
 278         fallback_ts = connman_setting_get_string_list("FallbackTimeservers");
 279
 280         /* Lastly add the fallback servers */
 281         for (i = 0; fallback_ts && fallback_ts[i]; i++)
 282                 list = __connman_timeserver_add_list(list, fallback_ts[i]);
 283
 284         return g_slist_reverse(list);
 285 }
 286
 287 static gboolean ts_recheck(gpointer user_data)
 288 {
 289         GSList *ts;
 290
 291         ts = __connman_timeserver_get_all(connman_service_get_default());
 292
 293         if (!ts) {
 294                 DBG("timeservers disabled");
 295
 296                 return TRUE;
 297         }
 298
 299         if (g_strcmp0(ts_current, ts->data) != 0) {
 300                 DBG("current %s preferred %s", ts_current, (char *)ts->data);
 301
 302                 g_slist_free_full(ts, g_free);
 303
 304                 __connman_timeserver_sync(NULL);
 305
 306                 return FALSE;
 307         }
 308
 309         DBG("");
 310
 311         g_slist_free_full(ts, g_free);
 312
 313         return TRUE;
 314 }
 315
 316 static void ts_recheck_disable(void)
 317 {
 318         if (ts_recheck_id == 0)
 319                 return;
 320
 321         g_source_remove(ts_recheck_id);
 322         ts_recheck_id = 0;
 323
 324         if (ts_backoff_id) {
 325                 g_source_remove(ts_backoff_id);
 326                 ts_backoff_id = 0;
 327         }
 328
 329         if (ts_current) {
 330                 g_free(ts_current);
 331                 ts_current = NULL;
 332         }
 333 }
 334
 335 static void ts_recheck_enable(void)
 336 {
 337         if (ts_recheck_id > 0)
 338                 return;
 339
 340         ts_recheck_id = g_timeout_add_seconds(TS_RECHECK_INTERVAL, ts_recheck,
 341                         NULL);
 342 }
 343
 344 /*
 345  * This function must be called everytime the default service changes, the
 346  * service timeserver(s) or gateway changes or the global timeserver(s) changes.
 347  */
 348 int __connman_timeserver_sync(struct connman_service *default_service)
 349 {
 350         struct connman_service *service;
 351         char **nameservers;
 352         int i;
 353
 354         if (default_service)
 355                 service = default_service;
 356         else
 357                 service = connman_service_get_default();
 358
 359         if (!service)
 360                 return -EINVAL;
 361
 362         if (service == ts_service)
 363                 return -EALREADY;
 364
 365         if (!resolv)
 366                 return 0;
 367         /*
 368          * Before we start creating the new timeserver list we must stop
 369          * any ongoing ntp query and server resolution.
 370          */
 371
 372         __connman_ntp_stop();
 373
 374         ts_recheck_disable();
 375
 376         if (resolv_id > 0)
 377                 g_resolv_cancel_lookup(resolv, resolv_id);
 378
 379         g_resolv_flush_nameservers(resolv);
 380
 381         nameservers = connman_service_get_nameservers(service);
 382         if (!nameservers)
 383                 return -EINVAL;
 384
 385         for (i = 0; nameservers[i]; i++)
 386                 g_resolv_add_nameserver(resolv, nameservers[i], 53, 0);
 387
 388         g_strfreev(nameservers);
 389
 390         g_slist_free_full(timeservers_list, g_free);
 391
 392         timeservers_list = __connman_timeserver_get_all(service);
 393
 394         __connman_service_timeserver_changed(service, timeservers_list);
 395
 396         if (!timeservers_list) {
 397                 DBG("No timeservers set.");
 398                 return 0;
 399         }
 400
 401         ts_recheck_enable();
 402
 403         ts_service = service;
 404         timeserver_sync_start();
 405
 406         return 0;
 407 }
 408
 409 static int timeserver_start(struct connman_service *service)
 410 {
 411         char **nameservers;
 412         int i;
 413
 414         DBG("service %p", service);
 415
 416         i = __connman_service_get_index(service);
 417         if (i < 0)
 418                 return -EINVAL;
 419
 420         nameservers = connman_service_get_nameservers(service);
 421
 422         /* Stop an already ongoing resolution, if there is one */
 423         if (resolv && resolv_id > 0)
 424                 g_resolv_cancel_lookup(resolv, resolv_id);
 425
 426         /* get rid of the old resolver */
 427         if (resolv) {
 428                 g_resolv_unref(resolv);
 429                 resolv = NULL;
 430         }
 431
 432         resolv = g_resolv_new(i);
 433         if (!resolv) {
 434                 g_strfreev(nameservers);
 435                 return -ENOMEM;
 436         }
 437
 438         if (getenv("CONNMAN_RESOLV_DEBUG"))
 439                 g_resolv_set_debug(resolv, resolv_debug, "RESOLV");
 440
 441         if (nameservers) {
 442                 for (i = 0; nameservers[i]; i++)
 443                         g_resolv_add_nameserver(resolv, nameservers[i], 53, 0);
 444
 445                 g_strfreev(nameservers);
 446         }
 447
 448         return __connman_timeserver_sync(service);
 449 }
 450
 451 static void timeserver_stop(void)
 452 {
 453         DBG(" ");
 454
 455         ts_service = NULL;
 456
 457         if (resolv) {
 458                 g_resolv_unref(resolv);
 459                 resolv = NULL;
 460         }
 461
 462         g_slist_free_full(timeservers_list, g_free);
 463         timeservers_list = NULL;
 464
 465         g_slist_free_full(ts_list, g_free);
 466         ts_list = NULL;
 467
 468         __connman_ntp_stop();
 469
 470         ts_recheck_disable();
 471 }
 472
 473 int __connman_timeserver_system_set(char **servers)
 474 {
 475         save_timeservers(servers);
 476
 477         __connman_timeserver_sync(NULL);
 478
 479         return 0;
 480 }
 481
 482 char **__connman_timeserver_system_get()
 483 {
 484         char **servers;
 485
 486         servers = load_timeservers();
 487         return servers;
 488 }
 489
 490 static void default_changed(struct connman_service *default_service)
 491 {
 492         if (default_service)
 493                 timeserver_start(default_service);
 494         else
 495                 timeserver_stop();
 496 }
 497
 498 static const struct connman_notifier timeserver_notifier = {
 499         .name                   = "timeserver",
 500         .default_changed        = default_changed,
 501 };
 502
 503 int __connman_timeserver_init(void)
 504 {
 505         DBG("");
 506
 507         connman_notifier_register(&timeserver_notifier);
 508
 509         return 0;
 510 }
 511
 512 void __connman_timeserver_cleanup(void)
 513 {
 514         DBG("");
 515
 516         connman_notifier_unregister(&timeserver_notifier);
 517 }