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 #define RESOLVER_FLAG_PUBLIC (1 << 0)
  36
  37 struct entry_data {
  38         struct connman_resolver *resolver;
  39         char *interface;
  40         char *domain;
  41         char *server;
  42         unsigned int flags;
  43 };
  44
  45 static GSList *entry_list = NULL;
  46 static GSList *resolver_list = NULL;
  47
  48 static void remove_entries(GSList *entries)
  49 {
  50         GSList *list;
  51
  52         for (list = entries; list; list = list->next) {
  53                 struct entry_data *entry = list->data;
  54                 struct connman_resolver *resolver = entry->resolver;
  55
  56                 entry_list = g_slist_remove(entry_list, entry);
  57
  58                 if (resolver && resolver->remove)
  59                         resolver->remove(entry->interface, entry->domain,
  60                                                                 entry->server);
  61
  62                 g_free(entry->server);
  63                 g_free(entry->domain);
  64                 g_free(entry->interface);
  65                 g_free(entry);
  66         }
  67
  68         g_slist_free(entries);
  69 }
  70
  71 static gint compare_priority(gconstpointer a, gconstpointer b)
  72 {
  73         const struct connman_resolver *resolver1 = a;
  74         const struct connman_resolver *resolver2 = b;
  75
  76         return resolver2->priority - resolver1->priority;
  77 }
  78
  79 /**
  80  * connman_resolver_register:
  81  * @resolver: resolver module
  82  *
  83  * Register a new resolver module
  84  *
  85  * Returns: %0 on success
  86  */
  87 int connman_resolver_register(struct connman_resolver *resolver)
  88 {
  89         GSList *list;
  90
  91         DBG("resolver %p name %s", resolver, resolver->name);
  92
  93         resolver_list = g_slist_insert_sorted(resolver_list, resolver,
  94                                                         compare_priority);
  95
  96         if (resolver->append == NULL)
  97                 return 0;
  98
  99         for (list = entry_list; list; list = list->next) {
 100                 struct entry_data *entry = list->data;
 101
 102                 if (entry->resolver)
 103                         continue;
 104
 105                 if (resolver->append(entry->interface, entry->domain,
 106                                                         entry->server) == 0)
 107                         entry->resolver = resolver;
 108         }
 109
 110         return 0;
 111 }
 112
 113 /**
 114  * connman_resolver_unregister:
 115  * @resolver: resolver module
 116  *
 117  * Remove a previously registered resolver module
 118  */
 119 void connman_resolver_unregister(struct connman_resolver *resolver)
 120 {
 121         GSList *list, *matches = NULL;
 122
 123         DBG("resolver %p name %s", resolver, resolver->name);
 124
 125         resolver_list = g_slist_remove(resolver_list, resolver);
 126
 127         for (list = entry_list; list; list = list->next) {
 128                 struct entry_data *entry = list->data;
 129
 130                 if (entry->resolver != resolver)
 131                         continue;
 132
 133                 matches = g_slist_append(matches, entry);
 134         }
 135
 136         remove_entries(matches);
 137 }
 138
 139 static int append_resolver(const char *interface, const char *domain,
 140                                         const char *server, unsigned int flags)
 141 {
 142         struct entry_data *entry;
 143         GSList *list;
 144
 145         DBG("interface %s domain %s server %s flags %d",
 146                                         interface, domain, server, flags);
 147
 148         if (server == NULL)
 149                 return -EINVAL;
 150
 151         entry = g_try_new0(struct entry_data, 1);
 152         if (entry == NULL)
 153                 return -ENOMEM;
 154
 155         entry->interface = g_strdup(interface);
 156         entry->domain = g_strdup(domain);
 157         entry->server = g_strdup(server);
 158         entry->flags = flags;
 159
 160         entry_list = g_slist_append(entry_list, entry);
 161
 162         for (list = resolver_list; list; list = list->next) {
 163                 struct connman_resolver *resolver = list->data;
 164
 165                 if (resolver->append == NULL)
 166                         continue;
 167
 168                 if (resolver->append(interface, domain, server) == 0) {
 169                         entry->resolver = resolver;
 170                         break;
 171                 }
 172         }
 173
 174         return 0;
 175 }
 176
 177 /**
 178  * connman_resolver_append:
 179  * @interface: network interface
 180  * @domain: domain limitation
 181  * @server: server address
 182  *
 183  * Append resolver server address to current list
 184  */
 185 int connman_resolver_append(const char *interface, const char *domain,
 186                                                         const char *server)
 187 {
 188         DBG("interface %s domain %s server %s", interface, domain, server);
 189
 190         return append_resolver(interface, domain, server, 0);
 191 }
 192
 193 /**
 194  * connman_resolver_remove:
 195  * @interface: network interface
 196  * @domain: domain limitation
 197  * @server: server address
 198  *
 199  * Remover resolver server address from current list
 200  */
 201 int connman_resolver_remove(const char *interface, const char *domain,
 202                                                         const char *server)
 203 {
 204         GSList *list, *matches = NULL;
 205
 206         DBG("interface %s domain %s server %s", interface, domain, server);
 207
 208         if (server == NULL)
 209                 return -EINVAL;
 210
 211         for (list = entry_list; list; list = list->next) {
 212                 struct entry_data *entry = list->data;
 213
 214                 if (interface != NULL &&
 215                                 g_strcmp0(entry->interface, interface) != 0)
 216                         continue;
 217
 218                 if (domain != NULL && g_strcmp0(entry->domain, domain) != 0)
 219                         continue;
 220
 221                 if (g_strcmp0(entry->server, server) != 0)
 222                         continue;
 223
 224                 matches = g_slist_append(matches, entry);
 225         }
 226
 227         if (matches == NULL)
 228                 return -ENOENT;
 229
 230         remove_entries(matches);
 231
 232         return 0;
 233 }
 234
 235 /**
 236  * connman_resolver_remove_all:
 237  * @interface: network interface
 238  *
 239  * Remove all resolver server address for the specified interface
 240  */
 241 int connman_resolver_remove_all(const char *interface)
 242 {
 243         GSList *list, *matches = NULL;
 244
 245         DBG("interface %s", interface);
 246
 247         if (interface == NULL)
 248                 return -EINVAL;
 249
 250         for (list = entry_list; list; list = list->next) {
 251                 struct entry_data *entry = list->data;
 252
 253                 if (g_strcmp0(entry->interface, interface) != 0)
 254                         continue;
 255
 256                 matches = g_slist_append(matches, entry);
 257         }
 258
 259         if (matches == NULL)
 260                 return -ENOENT;
 261
 262         remove_entries(matches);
 263
 264         return 0;
 265 }
 266
 267 /**
 268  * connman_resolver_append_public_server:
 269  * @server: server address
 270  *
 271  * Append public resolver server address to current list
 272  */
 273 int connman_resolver_append_public_server(const char *server)
 274 {
 275         DBG("server %s", server);
 276
 277         return append_resolver(NULL, NULL, server, RESOLVER_FLAG_PUBLIC);
 278 }
 279
 280 /**
 281  * connman_resolver_remove_public_server:
 282  * @server: server address
 283  *
 284  * Remove public resolver server address to current list
 285  */
 286 int connman_resolver_remove_public_server(const char *server)
 287 {
 288         DBG("server %s", server);
 289
 290         return connman_resolver_remove(NULL, NULL, server);
 291 }
 292
 293 static int selftest_append(const char *interface, const char *domain,
 294                                                         const char *server)
 295 {
 296         DBG("server %s", server);
 297
 298         return 0;
 299 }
 300
 301 static int selftest_remove(const char *interface, const char *domain,
 302                                                         const char *server)
 303 {
 304         DBG("server %s", server);
 305
 306         return 0;
 307 }
 308
 309 static struct connman_resolver selftest_resolver = {
 310         .name     = "selftest",
 311         .priority = CONNMAN_RESOLVER_PRIORITY_HIGH + 42,
 312         .append   = selftest_append,
 313         .remove   = selftest_remove,
 314 };
 315
 316 int __connman_resolver_selftest(void)
 317 {
 318         connman_resolver_append("wlan0", "lwn.net", "192.168.0.1");
 319
 320         connman_resolver_register(&selftest_resolver);
 321
 322         connman_resolver_append("eth0", "moblin.org", "192.168.42.1");
 323         connman_resolver_append("wlan0", "lwn.net", "192.168.0.2");
 324
 325         connman_resolver_append_public_server("8.8.8.8");
 326
 327         connman_resolver_remove_public_server("8.8.8.8");
 328
 329         connman_resolver_remove_all("wlan0");
 330
 331         connman_resolver_unregister(&selftest_resolver);
 332
 333         return 0;
 334 }
 335
 336 static int resolvfile_append(const char *interface, const char *domain,
 337                                                         const char *server)
 338 {
 339         char *cmd;
 340         int fd, len, err;
 341
 342         DBG("interface %s server %s", interface, server);
 343
 344         if (interface == NULL)
 345                 return -ENOENT;
 346
 347         fd = open("/etc/resolv.conf", O_RDWR | O_CREAT,
 348                                         S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 349         if (fd < 0)
 350                 return -errno;
 351
 352         err = ftruncate(fd, 0);
 353
 354         cmd = g_strdup_printf("# Generated by Connection Manager\n"
 355                                                 "options edns0\n"
 356                                                 "nameserver %s\n", server);
 357
 358         len = write(fd, cmd, strlen(cmd));
 359
 360         g_free(cmd);
 361
 362         close(fd);
 363
 364         return 0;
 365 }
 366
 367 static int resolvfile_remove(const char *interface, const char *domain,
 368                                                         const char *server)
 369 {
 370         DBG("interface %s server %s", interface, server);
 371
 372         return 0;
 373 }
 374
 375 static struct connman_resolver resolvfile_resolver = {
 376         .name           = "resolvfile",
 377         .priority       = CONNMAN_RESOLVER_PRIORITY_LOW,
 378         .append         = resolvfile_append,
 379         .remove         = resolvfile_remove,
 380 };
 381
 382 int __connman_resolver_init(void)
 383 {
 384         DBG("");
 385
 386         return connman_resolver_register(&resolvfile_resolver);
 387 }
 388
 389 void __connman_resolver_cleanup(void)
 390 {
 391         DBG("");
 392
 393         connman_resolver_unregister(&resolvfile_resolver);
 394 }