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         if (!simplified_log)
 110                 DBG("added server %s", server);
 111
 112         if (!simplified_log)
 113 #endif
 114         DBG("status %d", status);
 115
 116         if (status == G_RESOLV_RESULT_STATUS_SUCCESS) {
 117                 if (results) {
 118                         /* prepend the results in reverse order */
 119
 120                         for (i = 0; results[i]; i++)
 121                                 /* count */;
 122                         i--;
 123
 124                         for (; i >= 0; i--) {
 125                                 DBG("result[%d]: %s", i, results[i]);
 126
 127                                 ts_list = __connman_timeserver_add_list(
 128                                         ts_list, results[i]);
 129                         }
 130                 }
 131         }
 132
 133         sync_next();
 134 }
 135
 136 /*
 137  * Once the timeserver list (timeserver_list) is created, we start
 138  * querying the servers one by one. If resolving fails on one of them,
 139  * we move to the next one. The user can enter either an IP address or
 140  * a URL for the timeserver. We only resolve the URLs. Once we have an
 141  * IP for the NTP server, we start querying it for time corrections.
 142  */
 143 static void timeserver_sync_start(void)
 144 {
 145         GSList *list;
 146
 147         for (list = timeservers_list; list; list = list->next) {
 148                 char *timeserver = list->data;
 149
 150                 ts_list = g_slist_prepend(ts_list, g_strdup(timeserver));
 151         }
 152         ts_list = g_slist_reverse(ts_list);
 153
 154         sync_next();
 155 }
 156
 157 static gboolean timeserver_sync_restart(gpointer user_data)
 158 {
 159         timeserver_sync_start();
 160         ts_backoff_id = 0;
 161
 162         return FALSE;
 163 }
 164
 165 /*
 166  * Select the next time server from the working list (ts_list) because
 167  * for some reason the first time server in the list didn't work. If
 168  * none of the server did work we start over with the first server
 169  * with a backoff.
 170  */
 171 static void sync_next(void)
 172 {
 173         if (ts_current) {
 174                 g_free(ts_current);
 175                 ts_current = NULL;
 176         }
 177
 178         __connman_ntp_stop();
 179
 180         while (ts_list) {
 181                 ts_current = ts_list->data;
 182                 ts_list = g_slist_delete_link(ts_list, ts_list);
 183
 184                 /* if it's an IP, directly query it. */
 185                 if (connman_inet_check_ipaddress(ts_current) > 0) {
 186                         DBG("Using timeserver %s", ts_current);
 187                         __connman_ntp_start(ts_current, ntp_callback, NULL);
 188                         return;
 189                 }
 190 #if defined TIZEN_EXT
 191         if (!simplified_log)
 192 #endif
 193                 DBG("Resolving timeserver %s", ts_current);
 194 #if defined TIZEN_EXT
 195                 resolv_id = g_resolv_lookup_hostname(resolv, ts_current,
 196                                                 resolv_result, ts_current);
 197 #else
 198                 resolv_id = g_resolv_lookup_hostname(resolv, ts_current,
 199                                                 resolv_result, NULL);
 200 #endif
 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         GSList *ts;
 294
 295         ts = __connman_timeserver_get_all(connman_service_get_default());
 296
 297         if (!ts) {
 298                 DBG("timeservers disabled");
 299
 300                 return TRUE;
 301         }
 302
 303         if (g_strcmp0(ts_current, ts->data) != 0) {
 304                 DBG("current %s preferred %s", ts_current, (char *)ts->data);
 305
 306                 g_slist_free_full(ts, g_free);
 307
 308                 __connman_timeserver_sync(NULL);
 309
 310                 return FALSE;
 311         }
 312
 313         DBG("");
 314
 315         g_slist_free_full(ts, g_free);
 316
 317         return TRUE;
 318 }
 319
 320 static void ts_recheck_disable(void)
 321 {
 322         if (ts_recheck_id == 0)
 323                 return;
 324
 325         g_source_remove(ts_recheck_id);
 326         ts_recheck_id = 0;
 327
 328         if (ts_backoff_id) {
 329                 g_source_remove(ts_backoff_id);
 330                 ts_backoff_id = 0;
 331         }
 332
 333         if (ts_current) {
 334                 g_free(ts_current);
 335                 ts_current = NULL;
 336         }
 337 }
 338
 339 static void ts_recheck_enable(void)
 340 {
 341         if (ts_recheck_id > 0)
 342                 return;
 343
 344         ts_recheck_id = g_timeout_add_seconds(TS_RECHECK_INTERVAL, ts_recheck,
 345                         NULL);
 346 }
 347
 348 /*
 349  * This function must be called every time the default service changes, the
 350  * service timeserver(s) or gateway changes or the global timeserver(s) changes.
 351  */
 352 int __connman_timeserver_sync(struct connman_service *default_service)
 353 {
 354         struct connman_service *service;
 355         char **nameservers;
 356         int i;
 357
 358         if (default_service)
 359                 service = default_service;
 360         else
 361                 service = connman_service_get_default();
 362
 363         if (!service)
 364                 return -EINVAL;
 365
 366 #if !defined TIZEN_EXT
 367         if (service == ts_service)
 368                 return -EALREADY;
 369 #endif
 370
 371         if (!resolv)
 372                 return 0;
 373         /*
 374          * Before we start creating the new timeserver list we must stop
 375          * any ongoing ntp query and server resolution.
 376          */
 377
 378         __connman_ntp_stop();
 379
 380         ts_recheck_disable();
 381
 382         if (resolv_id > 0)
 383                 g_resolv_cancel_lookup(resolv, resolv_id);
 384
 385         g_resolv_flush_nameservers(resolv);
 386
 387         nameservers = connman_service_get_nameservers(service);
 388         if (!nameservers)
 389                 return -EINVAL;
 390
 391         for (i = 0; nameservers[i]; i++)
 392                 g_resolv_add_nameserver(resolv, nameservers[i], 53, 0);
 393
 394         g_strfreev(nameservers);
 395
 396         g_slist_free_full(timeservers_list, g_free);
 397
 398         timeservers_list = __connman_timeserver_get_all(service);
 399
 400         __connman_service_timeserver_changed(service, timeservers_list);
 401
 402         if (!timeservers_list) {
 403                 DBG("No timeservers set.");
 404                 return 0;
 405         }
 406
 407         ts_recheck_enable();
 408
 409         ts_service = service;
 410         timeserver_sync_start();
 411
 412         return 0;
 413 }
 414
 415 static int timeserver_start(struct connman_service *service)
 416 {
 417         char **nameservers;
 418         int i;
 419
 420         DBG("service %p", service);
 421
 422         i = __connman_service_get_index(service);
 423         if (i < 0)
 424                 return -EINVAL;
 425
 426         nameservers = connman_service_get_nameservers(service);
 427
 428         /* Stop an already ongoing resolution, if there is one */
 429         if (resolv && resolv_id > 0)
 430                 g_resolv_cancel_lookup(resolv, resolv_id);
 431
 432         /* get rid of the old resolver */
 433         if (resolv) {
 434                 g_resolv_unref(resolv);
 435                 resolv = NULL;
 436         }
 437
 438         resolv = g_resolv_new(i);
 439         if (!resolv) {
 440                 g_strfreev(nameservers);
 441                 return -ENOMEM;
 442         }
 443
 444         if (getenv("CONNMAN_RESOLV_DEBUG"))
 445                 g_resolv_set_debug(resolv, resolv_debug, "RESOLV");
 446
 447         if (nameservers) {
 448                 for (i = 0; nameservers[i]; i++)
 449                         g_resolv_add_nameserver(resolv, nameservers[i], 53, 0);
 450
 451                 g_strfreev(nameservers);
 452         }
 453
 454         return __connman_timeserver_sync(service);
 455 }
 456
 457 static void timeserver_stop(void)
 458 {
 459         DBG(" ");
 460
 461         ts_service = NULL;
 462
 463         if (resolv) {
 464                 g_resolv_unref(resolv);
 465                 resolv = NULL;
 466         }
 467
 468         g_slist_free_full(timeservers_list, g_free);
 469         timeservers_list = NULL;
 470
 471         g_slist_free_full(ts_list, g_free);
 472         ts_list = NULL;
 473
 474         __connman_ntp_stop();
 475
 476         ts_recheck_disable();
 477 }
 478
 479 int __connman_timeserver_system_set(char **servers)
 480 {
 481         save_timeservers(servers);
 482
 483         __connman_timeserver_sync(NULL);
 484
 485         return 0;
 486 }
 487
 488 char **__connman_timeserver_system_get()
 489 {
 490         char **servers;
 491
 492         servers = load_timeservers();
 493         return servers;
 494 }
 495
 496 static void default_changed(struct connman_service *default_service)
 497 {
 498         if (default_service)
 499                 timeserver_start(default_service);
 500         else
 501                 timeserver_stop();
 502 }
 503
 504 static const struct connman_notifier timeserver_notifier = {
 505         .name                   = "timeserver",
 506         .default_changed        = default_changed,
 507 };
 508
 509 int __connman_timeserver_init(void)
 510 {
 511         DBG("");
 512
 513         connman_notifier_register(&timeserver_notifier);
 514
 515         return 0;
 516 }
 517
 518 void __connman_timeserver_cleanup(void)
 519 {
 520         DBG("");
 521
 522         connman_notifier_unregister(&timeserver_notifier);
 523 }