src/resolver.c

   1 /*
   2  *
   3  *  Connection Manager
   4  *
   5  *  Copyright (C) 2007-2009  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 <stdio.h>
  27 #include <errno.h>
  28 #include <fcntl.h>
  29 #include <unistd.h>
  30 #include <string.h>
  31 #include <sys/stat.h>
  32
  33 #include "connman.h"
  34
  35 struct entry_data {
  36         struct connman_resolver *resolver;
  37         char *interface;
  38         char *domain;
  39         char *server;
  40 };
  41
  42 static GSList *entry_list = NULL;
  43 static GSList *resolver_list = NULL;
  44
  45 static void remove_entries(GSList *entries)
  46 {
  47         GSList *list;
  48
  49         for (list = entries; list; list = list->next) {
  50                 struct entry_data *entry = list->data;
  51                 struct connman_resolver *resolver = entry->resolver;
  52
  53                 entry_list = g_slist_remove(entry_list, entry);
  54
  55                 if (resolver && resolver->remove)
  56                         resolver->remove(entry->interface, entry->domain,
  57                                                                 entry->server);
  58
  59                 g_free(entry->server);
  60                 g_free(entry->domain);
  61                 g_free(entry->interface);
  62                 g_free(entry);
  63         }
  64
  65         g_slist_free(entries);
  66 }
  67
  68 static gint compare_priority(gconstpointer a, gconstpointer b)
  69 {
  70         const struct connman_resolver *resolver1 = a;
  71         const struct connman_resolver *resolver2 = b;
  72
  73         return resolver2->priority - resolver1->priority;
  74 }
  75
  76 /**
  77  * connman_resolver_register:
  78  * @resolver: resolver module
  79  *
  80  * Register a new resolver module
  81  *
  82  * Returns: %0 on success
  83  */
  84 int connman_resolver_register(struct connman_resolver *resolver)
  85 {
  86         GSList *list;
  87
  88         DBG("resolver %p name %s", resolver, resolver->name);
  89
  90         resolver_list = g_slist_insert_sorted(resolver_list, resolver,
  91                                                         compare_priority);
  92
  93         if (resolver->append == NULL)
  94                 return 0;
  95
  96         for (list = entry_list; list; list = list->next) {
  97                 struct entry_data *entry = list->data;
  98
  99                 if (entry->resolver)
 100                         continue;
 101
 102                 if (resolver->append(entry->interface, entry->domain,
 103                                                         entry->server) == 0)
 104                         entry->resolver = resolver;
 105         }
 106
 107         return 0;
 108 }
 109
 110 /**
 111  * connman_resolver_unregister:
 112  * @resolver: resolver module
 113  *
 114  * Remove a previously registered resolver module
 115  */
 116 void connman_resolver_unregister(struct connman_resolver *resolver)
 117 {
 118         GSList *list, *matches = NULL;
 119
 120         DBG("resolver %p name %s", resolver, resolver->name);
 121
 122         resolver_list = g_slist_remove(resolver_list, resolver);
 123
 124         for (list = entry_list; list; list = list->next) {
 125                 struct entry_data *entry = list->data;
 126
 127                 if (entry->resolver != resolver)
 128                         continue;
 129
 130                 matches = g_slist_append(matches, entry);
 131         }
 132
 133         remove_entries(matches);
 134 }
 135
 136 /**
 137  * connman_resolver_append:
 138  * @interface: network interface
 139  * @domain: domain limitation
 140  * @server: server address
 141  *
 142  * Append resolver server address to current list
 143  */
 144 int connman_resolver_append(const char *interface, const char *domain,
 145                                                         const char *server)
 146 {
 147         struct entry_data *entry;
 148         GSList *list;
 149
 150         DBG("interface %s domain %s server %s", interface, domain, server);
 151
 152         if (server == NULL)
 153                 return -EINVAL;
 154
 155         entry = g_try_new0(struct entry_data, 1);
 156         if (entry == NULL)
 157                 return -ENOMEM;
 158
 159         entry->interface = g_strdup(interface);
 160         entry->domain = g_strdup(domain);
 161         entry->server = g_strdup(server);
 162
 163         entry_list = g_slist_append(entry_list, entry);
 164
 165         for (list = resolver_list; list; list = list->next) {
 166                 struct connman_resolver *resolver = list->data;
 167
 168                 if (resolver->append == NULL)
 169                         continue;
 170
 171                 if (resolver->append(interface, domain, server) == 0) {
 172                         entry->resolver = resolver;
 173                         break;
 174                 }
 175         }
 176
 177         return 0;
 178 }
 179
 180 /**
 181  * connman_resolver_remove:
 182  * @interface: network interface
 183  * @domain: domain limitation
 184  * @server: server address
 185  *
 186  * Remover resolver server address from current list
 187  */
 188 int connman_resolver_remove(const char *interface, const char *domain,
 189                                                         const char *server)
 190 {
 191         GSList *list, *matches = NULL;
 192
 193         DBG("interface %s domain %s server %s", interface, domain, server);
 194
 195         if (server == NULL)
 196                 return -EINVAL;
 197
 198         for (list = entry_list; list; list = list->next) {
 199                 struct entry_data *entry = list->data;
 200
 201                 if (interface != NULL &&
 202                                 g_strcmp0(entry->interface, interface) != 0)
 203                         continue;
 204
 205                 if (domain != NULL && g_strcmp0(entry->domain, domain) != 0)
 206                         continue;
 207
 208                 if (g_strcmp0(entry->server, server) != 0)
 209                         continue;
 210
 211                 matches = g_slist_append(matches, entry);
 212         }
 213
 214         if (matches == NULL)
 215                 return -ENOENT;
 216
 217         remove_entries(matches);
 218
 219         return 0;
 220 }
 221
 222 /**
 223  * connman_resolver_remove_all:
 224  * @interface: network interface
 225  *
 226  * Remove all resolver server address for the specified interface
 227  */
 228 int connman_resolver_remove_all(const char *interface)
 229 {
 230         GSList *list, *matches = NULL;
 231
 232         DBG("interface %s", interface);
 233
 234         if (interface == NULL)
 235                 return -EINVAL;
 236
 237         for (list = entry_list; list; list = list->next) {
 238                 struct entry_data *entry = list->data;
 239
 240                 if (g_strcmp0(entry->interface, interface) != 0)
 241                         continue;
 242
 243                 matches = g_slist_append(matches, entry);
 244         }
 245
 246         if (matches == NULL)
 247                 return -ENOENT;
 248
 249         remove_entries(matches);
 250
 251         return 0;
 252 }
 253
 254 /**
 255  * connman_resolver_append_public_server:
 256  * @server: server address
 257  *
 258  * Append public resolver server address to current list
 259  */
 260 int connman_resolver_append_public_server(const char *server)
 261 {
 262         DBG("server %s", server);
 263
 264         return connman_resolver_append(NULL, NULL, server);
 265 }
 266
 267 /**
 268  * connman_resolver_remove_public_server:
 269  * @server: server address
 270  *
 271  * Remove public resolver server address to current list
 272  */
 273 int connman_resolver_remove_public_server(const char *server)
 274 {
 275         DBG("server %s", server);
 276
 277         return connman_resolver_remove(NULL, NULL, server);
 278 }
 279
 280 static int selftest_append(const char *interface, const char *domain,
 281                                                         const char *server)
 282 {
 283         DBG("server %s", server);
 284
 285         return 0;
 286 }
 287
 288 static int selftest_remove(const char *interface, const char *domain,
 289                                                         const char *server)
 290 {
 291         DBG("server %s", server);
 292
 293         return 0;
 294 }
 295
 296 static struct connman_resolver selftest_resolver = {
 297         .name     = "selftest",
 298         .priority = CONNMAN_RESOLVER_PRIORITY_HIGH + 42,
 299         .append   = selftest_append,
 300         .remove   = selftest_remove,
 301 };
 302
 303 int __connman_resolver_selftest(void)
 304 {
 305         connman_resolver_append("wlan0", "lwn.net", "192.168.0.1");
 306
 307         connman_resolver_register(&selftest_resolver);
 308
 309         connman_resolver_append("eth0", "moblin.org", "192.168.42.1");
 310         connman_resolver_append("wlan0", "lwn.net", "192.168.0.2");
 311
 312         connman_resolver_append_public_server("8.8.8.8");
 313
 314         connman_resolver_remove_public_server("8.8.8.8");
 315
 316         connman_resolver_remove_all("wlan0");
 317
 318         connman_resolver_unregister(&selftest_resolver);
 319
 320         return 0;
 321 }
 322
 323 static int resolvfile_append(const char *interface, const char *domain,
 324                                                         const char *server)
 325 {
 326         char *cmd;
 327         int fd, len, err;
 328
 329         DBG("interface %s server %s", interface, server);
 330
 331         fd = open("/etc/resolv.conf", O_RDWR | O_CREAT,
 332                                         S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 333         if (fd < 0)
 334                 return -errno;
 335
 336         err = ftruncate(fd, 0);
 337
 338         cmd = g_strdup_printf("# Generated by Connection Manager\n"
 339                                                 "options edns0\n"
 340                                                 "nameserver %s\n", server);
 341
 342         len = write(fd, cmd, strlen(cmd));
 343
 344         g_free(cmd);
 345
 346         close(fd);
 347
 348         return 0;
 349 }
 350
 351 static int resolvfile_remove(const char *interface, const char *domain,
 352                                                         const char *server)
 353 {
 354         DBG("interface %s server %s", interface, server);
 355
 356         return 0;
 357 }
 358
 359 static struct connman_resolver resolvfile_resolver = {
 360         .name           = "resolvfile",
 361         .priority       = CONNMAN_RESOLVER_PRIORITY_LOW,
 362         .append         = resolvfile_append,
 363         .remove         = resolvfile_remove,
 364 };
 365
 366 int __connman_resolver_init(void)
 367 {
 368         DBG("");
 369
 370         return connman_resolver_register(&resolvfile_resolver);
 371 }
 372
 373 void __connman_resolver_cleanup(void)
 374 {
 375         DBG("");
 376
 377         connman_resolver_unregister(&resolvfile_resolver);
 378 }