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 GSList *ts_list = NULL;
  38 static char *ts_current = NULL;
  39 static int ts_recheck_id = 0;
  40
  41 static GResolv *resolv = NULL;
  42 static int resolv_id = 0;
  43
  44 static void resolv_debug(const char *str, void *data)
  45 {
  46         connman_info("%s: %s\n", (const char *) data, str);
  47 }
  48 static void save_timeservers(char **servers)
  49 {
  50         GKeyFile *keyfile;
  51         int cnt;
  52
  53         keyfile = __connman_storage_load_global();
  54         if (!keyfile)
  55                 keyfile = g_key_file_new();
  56
  57         for (cnt = 0; servers && servers[cnt]; cnt++);
  58
  59         g_key_file_set_string_list(keyfile, "global", "Timeservers",
  60                            (const gchar **)servers, cnt);
  61
  62         __connman_storage_save_global(keyfile);
  63
  64         g_key_file_free(keyfile);
  65
  66         return;
  67 }
  68
  69 static char **load_timeservers(void)
  70 {
  71         GKeyFile *keyfile;
  72         char **servers = NULL;
  73
  74         keyfile = __connman_storage_load_global();
  75         if (!keyfile)
  76                 return NULL;
  77
  78         servers = g_key_file_get_string_list(keyfile, "global",
  79                                                 "Timeservers", NULL, NULL);
  80
  81         g_key_file_free(keyfile);
  82
  83         return servers;
  84 }
  85
  86 static void resolv_result(GResolvResultStatus status, char **results,
  87                                 gpointer user_data)
  88 {
  89         int i;
  90
  91         DBG("status %d", status);
  92
  93         if (status == G_RESOLV_RESULT_STATUS_SUCCESS) {
  94                 if (results) {
  95                         for (i = 0; results[i]; i++) {
  96                                 DBG("result[%d]: %s", i, results[i]);
  97                                 if (i == 0)
  98                                         continue;
  99
 100                                 ts_list = __connman_timeserver_add_list(
 101                                                         ts_list, results[i]);
 102                         }
 103
 104                         DBG("Using timeserver %s", results[0]);
 105
 106                         __connman_ntp_start(results[0]);
 107
 108                         return;
 109                 }
 110         }
 111
 112         /* If resolving fails, move to the next server */
 113         __connman_timeserver_sync_next();
 114 }
 115
 116 /*
 117  * Once the timeserver list (ts_list) is created, we start querying the
 118  * servers one by one. If resolving fails on one of them, we move to the
 119  * next one. The user can enter either an IP address or a URL for the
 120  * timeserver. We only resolve the URLs. Once we have an IP for the NTP
 121  * server, we start querying it for time corrections.
 122  */
 123 void __connman_timeserver_sync_next()
 124 {
 125         if (ts_current) {
 126                 g_free(ts_current);
 127                 ts_current = NULL;
 128         }
 129
 130         __connman_ntp_stop();
 131
 132         /* Get the 1st server in the list */
 133         if (!ts_list)
 134                 return;
 135
 136         ts_current = ts_list->data;
 137
 138         ts_list = g_slist_delete_link(ts_list, ts_list);
 139
 140         /* if it's an IP, directly query it. */
 141         if (connman_inet_check_ipaddress(ts_current) > 0) {
 142                 DBG("Using timeserver %s", ts_current);
 143
 144                 __connman_ntp_start(ts_current);
 145
 146                 return;
 147         }
 148
 149         DBG("Resolving timeserver %s", ts_current);
 150
 151         resolv_id = g_resolv_lookup_hostname(resolv, ts_current,
 152                                                 resolv_result, NULL);
 153
 154         return;
 155 }
 156
 157 GSList *__connman_timeserver_add_list(GSList *server_list,
 158                 const char *timeserver)
 159 {
 160         GSList *list = server_list;
 161
 162         if (!timeserver)
 163                 return server_list;
 164
 165         while (list) {
 166                 char *existing_server = list->data;
 167                 if (strcmp(timeserver, existing_server) == 0)
 168                         return server_list;
 169                 list = g_slist_next(list);
 170         }
 171         return g_slist_prepend(server_list, g_strdup(timeserver));
 172 }
 173
 174 /*
 175  * __connman_timeserver_get_all function creates the timeserver
 176  * list which will be used to determine NTP server for time corrections.
 177  * The service settings take priority over the global timeservers.
 178  */
 179 GSList *__connman_timeserver_get_all(struct connman_service *service)
 180 {
 181         GSList *list = NULL;
 182         struct connman_network *network;
 183         char **timeservers;
 184         char **service_ts;
 185         char **service_ts_config;
 186         const char *service_gw;
 187         char **fallback_ts;
 188         int index, i;
 189
 190         if (__connman_clock_timeupdates() == TIME_UPDATES_MANUAL)
 191                 return NULL;
 192
 193         service_ts_config = connman_service_get_timeservers_config(service);
 194
 195         /* First add Service Timeservers.Configuration to the list */
 196         for (i = 0; service_ts_config && service_ts_config[i];
 197                         i++)
 198                 list = __connman_timeserver_add_list(list,
 199                                 service_ts_config[i]);
 200
 201         service_ts = connman_service_get_timeservers(service);
 202
 203         /* Then add Service Timeservers via DHCP to the list */
 204         for (i = 0; service_ts && service_ts[i]; i++)
 205                 list = __connman_timeserver_add_list(list, service_ts[i]);
 206
 207         network = __connman_service_get_network(service);
 208         if (network) {
 209                 index = connman_network_get_index(network);
 210                 service_gw = __connman_ipconfig_get_gateway_from_index(index,
 211                         CONNMAN_IPCONFIG_TYPE_ALL);
 212
 213                 /* Then add Service Gateway to the list */
 214                 if (service_gw)
 215                         list = __connman_timeserver_add_list(list, service_gw);
 216         }
 217
 218         /* Then add Global Timeservers to the list */
 219         timeservers = load_timeservers();
 220
 221         for (i = 0; timeservers && timeservers[i]; i++)
 222                 list = __connman_timeserver_add_list(list, timeservers[i]);
 223
 224         g_strfreev(timeservers);
 225
 226         fallback_ts = connman_setting_get_string_list("FallbackTimeservers");
 227
 228         /* Lastly add the fallback servers */
 229         for (i = 0; fallback_ts && fallback_ts[i]; i++)
 230                 list = __connman_timeserver_add_list(list, fallback_ts[i]);
 231
 232         return g_slist_reverse(list);
 233 }
 234
 235 static gboolean ts_recheck(gpointer user_data)
 236 {
 237         GSList *ts;
 238
 239         ts = __connman_timeserver_get_all(__connman_service_get_default());
 240
 241         if (!ts) {
 242                 DBG("timeservers disabled");
 243
 244                 return TRUE;
 245         }
 246
 247         if (g_strcmp0(ts_current, ts->data) != 0) {
 248                 DBG("current %s preferred %s", ts_current, (char *)ts->data);
 249
 250                 g_slist_free_full(ts, g_free);
 251
 252                 __connman_timeserver_sync(NULL);
 253
 254                 return FALSE;
 255         }
 256
 257         DBG("");
 258
 259         g_slist_free_full(ts, g_free);
 260
 261         return TRUE;
 262 }
 263
 264 static void ts_recheck_disable(void)
 265 {
 266         if (ts_recheck_id == 0)
 267                 return;
 268
 269         g_source_remove(ts_recheck_id);
 270         ts_recheck_id = 0;
 271
 272         if (ts_current) {
 273                 g_free(ts_current);
 274                 ts_current = NULL;
 275         }
 276 }
 277
 278 static void ts_recheck_enable(void)
 279 {
 280         if (ts_recheck_id > 0)
 281                 return;
 282
 283         ts_recheck_id = g_timeout_add_seconds(TS_RECHECK_INTERVAL, ts_recheck,
 284                         NULL);
 285 }
 286
 287 /*
 288  * This function must be called everytime the default service changes, the
 289  * service timeserver(s) or gateway changes or the global timeserver(s) changes.
 290  */
 291 int __connman_timeserver_sync(struct connman_service *default_service)
 292 {
 293         struct connman_service *service;
 294         char **nameservers;
 295         int i;
 296
 297         if (default_service)
 298                 service = default_service;
 299         else
 300                 service = __connman_service_get_default();
 301
 302         if (!service)
 303                 return -EINVAL;
 304
 305         if (!resolv)
 306                 return 0;
 307         /*
 308          * Before we start creating the new timeserver list we must stop
 309          * any ongoing ntp query and server resolution.
 310          */
 311
 312         __connman_ntp_stop();
 313
 314         ts_recheck_disable();
 315
 316         if (resolv_id > 0)
 317                 g_resolv_cancel_lookup(resolv, resolv_id);
 318
 319         g_resolv_flush_nameservers(resolv);
 320
 321         nameservers = connman_service_get_nameservers(service);
 322         if (!nameservers)
 323                 return -EINVAL;
 324
 325         for (i = 0; nameservers[i]; i++)
 326                 g_resolv_add_nameserver(resolv, nameservers[i], 53, 0);
 327
 328         g_strfreev(nameservers);
 329
 330         g_slist_free_full(ts_list, g_free);
 331
 332         ts_list = __connman_timeserver_get_all(service);
 333
 334         __connman_service_timeserver_changed(service, ts_list);
 335
 336         if (!ts_list) {
 337                 DBG("No timeservers set.");
 338                 return 0;
 339         }
 340
 341         ts_recheck_enable();
 342
 343         __connman_timeserver_sync_next();
 344
 345         return 0;
 346 }
 347
 348 static int timeserver_start(struct connman_service *service)
 349 {
 350         char **nameservers;
 351         int i;
 352
 353         DBG("service %p", service);
 354
 355         i = __connman_service_get_index(service);
 356         if (i < 0)
 357                 return -EINVAL;
 358
 359         nameservers = connman_service_get_nameservers(service);
 360         if (!nameservers)
 361                 return -EINVAL;
 362
 363         /* Stop an already ongoing resolution, if there is one */
 364         if (resolv && resolv_id > 0)
 365                 g_resolv_cancel_lookup(resolv, resolv_id);
 366
 367         /* get rid of the old resolver */
 368         if (resolv) {
 369                 g_resolv_unref(resolv);
 370                 resolv = NULL;
 371         }
 372
 373         resolv = g_resolv_new(i);
 374         if (!resolv) {
 375                 g_strfreev(nameservers);
 376                 return -ENOMEM;
 377         }
 378
 379         if (getenv("CONNMAN_RESOLV_DEBUG"))
 380                 g_resolv_set_debug(resolv, resolv_debug, "RESOLV");
 381
 382         for (i = 0; nameservers[i]; i++)
 383                 g_resolv_add_nameserver(resolv, nameservers[i], 53, 0);
 384
 385         g_strfreev(nameservers);
 386
 387         return __connman_timeserver_sync(service);
 388 }
 389
 390 static void timeserver_stop(void)
 391 {
 392         DBG(" ");
 393
 394         if (resolv) {
 395                 g_resolv_unref(resolv);
 396                 resolv = NULL;
 397         }
 398
 399         g_slist_free_full(ts_list, g_free);
 400
 401         ts_list = NULL;
 402
 403         __connman_ntp_stop();
 404
 405         ts_recheck_disable();
 406 }
 407
 408 int __connman_timeserver_system_set(char **servers)
 409 {
 410         save_timeservers(servers);
 411
 412         __connman_timeserver_sync(NULL);
 413
 414         return 0;
 415 }
 416
 417 char **__connman_timeserver_system_get()
 418 {
 419         char **servers;
 420
 421         servers = load_timeservers();
 422         return servers;
 423 }
 424
 425 static void default_changed(struct connman_service *default_service)
 426 {
 427         if (default_service)
 428                 timeserver_start(default_service);
 429         else
 430                 timeserver_stop();
 431 }
 432
 433 static struct connman_notifier timeserver_notifier = {
 434         .name                   = "timeserver",
 435         .default_changed        = default_changed,
 436 };
 437
 438 int __connman_timeserver_init(void)
 439 {
 440         DBG("");
 441
 442         connman_notifier_register(&timeserver_notifier);
 443
 444         return 0;
 445 }
 446
 447 void __connman_timeserver_cleanup(void)
 448 {
 449         DBG("");
 450
 451         connman_notifier_unregister(&timeserver_notifier);
 452 }