gio/gresolver.c

   1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
   2
   3 /* GIO - GLib Input, Output and Streaming Library
   4  *
   5  * Copyright (C) 2008 Red Hat, Inc.
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General
  18  * Public License along with this library; if not, write to the
  19  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20  * Boston, MA 02111-1307, USA.
  21  */
  22
  23 #include "config.h"
  24 #include <glib.h>
  25 #include "glibintl.h"
  26
  27 #include "gresolver.h"
  28 #include "gnetworkingprivate.h"
  29 #include "gasyncresult.h"
  30 #include "ginetaddress.h"
  31 #include "ginetsocketaddress.h"
  32 #include "gsimpleasyncresult.h"
  33 #include "gsrvtarget.h"
  34
  35 #ifdef G_OS_UNIX
  36 #include "gunixresolver.h"
  37 #include <sys/stat.h>
  38 #endif
  39 #ifdef G_OS_WIN32
  40 #include "gwin32resolver.h"
  41 #endif
  42
  43 #include <stdlib.h>
  44
  45 #include "gioalias.h"
  46
  47 /**
  48  * SECTION:gresolver
  49  * @short_description: Asynchronous and cancellable DNS resolver
  50  * @include: gio/gio.h
  51  *
  52  * #GResolver provides cancellable synchronous and asynchronous DNS
  53  * resolution, for hostnames (g_resolver_lookup_by_address(),
  54  * g_resolver_lookup_by_name() and their async variants) and SRV
  55  * (service) records (g_resolver_lookup_service()).
  56  *
  57  * #GNetworkAddress and #GNetworkService provide wrappers around
  58  * #GResolver functionality that also implement #GSocketConnectable,
  59  * making it easy to connect to a remote host/service.
  60  */
  61
  62 enum {
  63   RELOAD,
  64   LAST_SIGNAL
  65 };
  66
  67 static guint signals[LAST_SIGNAL] = { 0 };
  68
  69 struct _GResolverPrivate {
  70 #ifdef G_OS_UNIX
  71   time_t resolv_conf_timestamp;
  72 #else
  73   int dummy;
  74 #endif
  75 };
  76
  77 /**
  78  * GResolver:
  79  *
  80  * The object that handles DNS resolution. Use g_resolver_get_default()
  81  * to get the default resolver.
  82  */
  83 G_DEFINE_TYPE (GResolver, g_resolver, G_TYPE_OBJECT)
  84
  85 static void
  86 g_resolver_class_init (GResolverClass *resolver_class)
  87 {
  88   volatile GType type;
  89
  90   g_type_class_add_private (resolver_class, sizeof (GResolverPrivate));
  91
  92   /* Make sure _g_networking_init() has been called */
  93   type = g_inet_address_get_type ();
  94
  95   /* Initialize _g_resolver_addrinfo_hints */
  96 #ifdef AI_ADDRCONFIG
  97   _g_resolver_addrinfo_hints.ai_flags |= AI_ADDRCONFIG;
  98 #endif
  99   /* These two don't actually matter, they just get copied into the
 100    * returned addrinfo structures (and then we ignore them). But if
 101    * we leave them unset, we'll get back duplicate answers.
 102    */
 103   _g_resolver_addrinfo_hints.ai_socktype = SOCK_STREAM;
 104   _g_resolver_addrinfo_hints.ai_protocol = IPPROTO_TCP;
 105
 106   /**
 107    * GResolver::reload:
 108    * @resolver: a #GResolver
 109    *
 110    * Emitted when the resolver notices that the system resolver
 111    * configuration has changed.
 112    **/
 113   signals[RELOAD] =
 114     g_signal_new (I_("reload"),
 115                   G_TYPE_RESOLVER,
 116                   G_SIGNAL_RUN_LAST,
 117                   G_STRUCT_OFFSET (GResolverClass, reload),
 118                   NULL, NULL,
 119                   g_cclosure_marshal_VOID__VOID,
 120                   G_TYPE_NONE, 0);
 121 }
 122
 123 static void
 124 g_resolver_init (GResolver *resolver)
 125 {
 126 #ifdef G_OS_UNIX
 127   struct stat st;
 128 #endif
 129
 130   resolver->priv = G_TYPE_INSTANCE_GET_PRIVATE (resolver, G_TYPE_RESOLVER, GResolverPrivate);
 131
 132 #ifdef G_OS_UNIX
 133   if (stat (_PATH_RESCONF, &st) == 0)
 134     resolver->priv->resolv_conf_timestamp = st.st_mtime;
 135 #endif
 136 }
 137
 138 static GResolver *default_resolver;
 139
 140 /**
 141  * g_resolver_get_default:
 142  *
 143  * Gets the default #GResolver. You should unref it when you are done
 144  * with it. #GResolver may use its reference count as a hint about how
 145  * many threads/processes, etc it should allocate for concurrent DNS
 146  * resolutions.
 147  *
 148  * Return value: the default #GResolver.
 149  *
 150  * Since: 2.22
 151  */
 152 GResolver *
 153 g_resolver_get_default (void)
 154 {
 155   if (!default_resolver)
 156     {
 157       if (g_thread_supported ())
 158         default_resolver = g_object_new (G_TYPE_THREADED_RESOLVER, NULL);
 159       else
 160         {
 161 #if defined(G_OS_UNIX)
 162           default_resolver = g_object_new (G_TYPE_UNIX_RESOLVER, NULL);
 163 #elif defined(G_OS_WIN32)
 164           default_resolver = g_object_new (G_TYPE_WIN32_RESOLVER, NULL);
 165 #endif
 166         }
 167     }
 168
 169   return g_object_ref (default_resolver);
 170 }
 171
 172 /**
 173  * g_resolver_set_default:
 174  * @resolver: the new default #GResolver
 175  *
 176  * Sets @resolver to be the application's default resolver (reffing
 177  * @resolver, and unreffing the previous default resolver, if any).
 178  * Future calls to g_resolver_get_default() will return this resolver.
 179  *
 180  * This can be used if an application wants to perform any sort of DNS
 181  * caching or "pinning"; it can implement its own #GResolver that
 182  * calls the original default resolver for DNS operations, and
 183  * implements its own cache policies on top of that, and then set
 184  * itself as the default resolver for all later code to use.
 185  *
 186  * Since: 2.22
 187  */
 188 void
 189 g_resolver_set_default (GResolver *resolver)
 190 {
 191   if (default_resolver)
 192     g_object_unref (default_resolver);
 193   default_resolver = g_object_ref (resolver);
 194 }
 195
 196
 197 static void
 198 g_resolver_maybe_reload (GResolver *resolver)
 199 {
 200 #ifdef G_OS_UNIX
 201   struct stat st;
 202
 203   if (stat (_PATH_RESCONF, &st) == 0)
 204     {
 205       if (st.st_mtime != resolver->priv->resolv_conf_timestamp)
 206         {
 207           resolver->priv->resolv_conf_timestamp = st.st_mtime;
 208           res_init ();
 209           g_signal_emit (resolver, signals[RELOAD], 0);
 210         }
 211     }
 212 #endif
 213 }
 214
 215 /**
 216  * g_resolver_lookup_by_name:
 217  * @resolver: a #GResolver
 218  * @hostname: the hostname to look up
 219  * @cancellable: a #GCancellable, or %NULL
 220  * @error: return location for a #GError, or %NULL
 221  *
 222  * Synchronously resolves @hostname to determine its associated IP
 223  * address(es). @hostname may be an ASCII-only or UTF-8 hostname, or
 224  * the textual form of an IP address (in which case this just becomes
 225  * a wrapper around g_inet_address_new_from_string()).
 226  *
 227  * On success, g_resolver_lookup_by_name() will return a #GList of
 228  * #GInetAddress, sorted in order of preference. (That is, you should
 229  * attempt to connect to the first address first, then the second if
 230  * the first fails, etc.)
 231  *
 232  * If the DNS resolution fails, @error (if non-%NULL) will be set to a
 233  * value from #GResolverError.
 234  *
 235  * If @cancellable is non-%NULL, it can be used to cancel the
 236  * operation, in which case @error (if non-%NULL) will be set to
 237  * %G_IO_ERROR_CANCELLED.
 238  *
 239  * If you are planning to connect to a socket on the resolved IP
 240  * address, it may be easier to create a #GNetworkAddress and use its
 241  * #GSocketConnectable interface.
 242  *
 243  * Return value: a #GList of #GInetAddress, or %NULL on error. You
 244  * must unref each of the addresses and free the list when you are
 245  * done with it. (You can use g_resolver_free_addresses() to do this.)
 246  *
 247  * Since: 2.22
 248  */
 249 GList *
 250 g_resolver_lookup_by_name (GResolver     *resolver,
 251                            const gchar   *hostname,
 252                            GCancellable  *cancellable,
 253                            GError       **error)
 254 {
 255   GInetAddress *addr;
 256   GList *addrs;
 257   gchar *ascii_hostname = NULL;
 258
 259   g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
 260   g_return_val_if_fail (hostname != NULL, NULL);
 261
 262   /* Check if @hostname is just an IP address */
 263   addr = g_inet_address_new_from_string (hostname);
 264   if (addr)
 265     return g_list_append (NULL, addr);
 266
 267   if (g_hostname_is_non_ascii (hostname))
 268     hostname = ascii_hostname = g_hostname_to_ascii (hostname);
 269
 270   g_resolver_maybe_reload (resolver);
 271   addrs = G_RESOLVER_GET_CLASS (resolver)->
 272     lookup_by_name (resolver, hostname, cancellable, error);
 273
 274   g_free (ascii_hostname);
 275   return addrs;
 276 }
 277
 278 /**
 279  * g_resolver_lookup_by_name_async:
 280  * @resolver: a #GResolver
 281  * @hostname: the hostname to look up the address of
 282  * @cancellable: a #GCancellable, or %NULL
 283  * @callback: callback to call after resolution completes
 284  * @user_data: data for @callback
 285  *
 286  * Begins asynchronously resolving @hostname to determine its
 287  * associated IP address(es), and eventually calls @callback, which
 288  * must call g_resolver_lookup_by_name_finish() to get the result.
 289  * See g_resolver_lookup_by_name() for more details.
 290  *
 291  * Since: 2.22
 292  */
 293 void
 294 g_resolver_lookup_by_name_async (GResolver           *resolver,
 295                                  const gchar         *hostname,
 296                                  GCancellable        *cancellable,
 297                                  GAsyncReadyCallback  callback,
 298                                  gpointer             user_data)
 299 {
 300   GInetAddress *addr;
 301   gchar *ascii_hostname = NULL;
 302
 303   g_return_if_fail (G_IS_RESOLVER (resolver));
 304   g_return_if_fail (hostname != NULL);
 305
 306   /* Check if @hostname is just an IP address */
 307   addr = g_inet_address_new_from_string (hostname);
 308   if (addr)
 309     {
 310       GSimpleAsyncResult *simple;
 311
 312       simple = g_simple_async_result_new (G_OBJECT (resolver),
 313                                           callback, user_data,
 314                                           g_resolver_lookup_by_name_async);
 315
 316       g_simple_async_result_set_op_res_gpointer (simple, addr, g_object_unref);
 317       g_simple_async_result_complete_in_idle (simple);
 318       g_object_unref (simple);
 319       return;
 320     }
 321
 322   if (g_hostname_is_non_ascii (hostname))
 323     hostname = ascii_hostname = g_hostname_to_ascii (hostname);
 324
 325   g_resolver_maybe_reload (resolver);
 326   G_RESOLVER_GET_CLASS (resolver)->
 327     lookup_by_name_async (resolver, hostname, cancellable, callback, user_data);
 328
 329   g_free (ascii_hostname);
 330 }
 331
 332 /**
 333  * g_resolver_lookup_by_name_finish:
 334  * @resolver: a #GResolver
 335  * @result: the result passed to your #GAsyncReadyCallback
 336  * @error: return location for a #GError, or %NULL
 337  *
 338  * Retrieves the result of a call to
 339  * g_resolver_lookup_by_name_async().
 340  *
 341  * If the DNS resolution failed, @error (if non-%NULL) will be set to
 342  * a value from #GResolverError. If the operation was cancelled,
 343  * @error will be set to %G_IO_ERROR_CANCELLED.
 344  *
 345  * Return value: a #GList of #GInetAddress, or %NULL on error. See
 346  * g_resolver_lookup_by_name() for more details.
 347  *
 348  * Since: 2.22
 349  */
 350 GList *
 351 g_resolver_lookup_by_name_finish (GResolver     *resolver,
 352                                   GAsyncResult  *result,
 353                                   GError       **error)
 354 {
 355   g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
 356
 357   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 358     {
 359       GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
 360
 361       if (g_simple_async_result_propagate_error (simple, error))
 362         return NULL;
 363
 364       /* Handle the stringified-IP-addr case */
 365       if (g_simple_async_result_get_source_tag (simple) == g_resolver_lookup_by_name_async)
 366         {
 367           GInetAddress *addr;
 368
 369           addr = g_simple_async_result_get_op_res_gpointer (simple);
 370           return g_list_append (NULL, g_object_ref (addr));
 371         }
 372     }
 373
 374   return G_RESOLVER_GET_CLASS (resolver)->
 375     lookup_by_name_finish (resolver, result, error);
 376 }
 377
 378 /**
 379  * g_resolver_free_addresses:
 380  * @addresses: a #GList of #GInetAddress
 381  *
 382  * Frees @addresses (which should be the return value from
 383  * g_resolver_lookup_by_name() or g_resolver_lookup_by_name_finish()).
 384  * (This is a convenience method; you can also simply free the results
 385  * by hand.)
 386  *
 387  * Since: 2.22
 388  */
 389 void
 390 g_resolver_free_addresses (GList *addresses)
 391 {
 392   GList *a;
 393
 394   for (a = addresses; a; a = a->next)
 395     g_object_unref (a->data);
 396   g_list_free (addresses);
 397 }
 398
 399 /**
 400  * g_resolver_lookup_by_address:
 401  * @resolver: a #GResolver
 402  * @address: the address to reverse-resolve
 403  * @cancellable: a #GCancellable, or %NULL
 404  * @error: return location for a #GError, or %NULL
 405  *
 406  * Synchronously reverse-resolves @address to determine its
 407  * associated hostname.
 408  *
 409  * If the DNS resolution fails, @error (if non-%NULL) will be set to
 410  * a value from #GResolverError.
 411  *
 412  * If @cancellable is non-%NULL, it can be used to cancel the
 413  * operation, in which case @error (if non-%NULL) will be set to
 414  * %G_IO_ERROR_CANCELLED.
 415  *
 416  * Return value: a hostname (either ASCII-only, or in ASCII-encoded
 417  *     form), or %NULL on error.
 418  *
 419  * Since: 2.22
 420  */
 421 gchar *
 422 g_resolver_lookup_by_address (GResolver     *resolver,
 423                               GInetAddress  *address,
 424                               GCancellable  *cancellable,
 425                               GError       **error)
 426 {
 427   g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
 428   g_return_val_if_fail (G_IS_INET_ADDRESS (address), NULL);
 429
 430   g_resolver_maybe_reload (resolver);
 431   return G_RESOLVER_GET_CLASS (resolver)->
 432     lookup_by_address (resolver, address, cancellable, error);
 433 }
 434
 435 /**
 436  * g_resolver_lookup_by_address_async:
 437  * @resolver: a #GResolver
 438  * @address: the address to reverse-resolve
 439  * @cancellable: a #GCancellable, or %NULL
 440  * @callback: callback to call after resolution completes
 441  * @user_data: data for @callback
 442  *
 443  * Begins asynchronously reverse-resolving @address to determine its
 444  * associated hostname, and eventually calls @callback, which must
 445  * call g_resolver_lookup_by_address_finish() to get the final result.
 446  *
 447  * Since: 2.22
 448  */
 449 void
 450 g_resolver_lookup_by_address_async (GResolver           *resolver,
 451                                     GInetAddress        *address,
 452                                     GCancellable        *cancellable,
 453                                     GAsyncReadyCallback  callback,
 454                                     gpointer             user_data)
 455 {
 456   g_return_if_fail (G_IS_RESOLVER (resolver));
 457   g_return_if_fail (G_IS_INET_ADDRESS (address));
 458
 459   g_resolver_maybe_reload (resolver);
 460   G_RESOLVER_GET_CLASS (resolver)->
 461     lookup_by_address_async (resolver, address, cancellable, callback, user_data);
 462 }
 463
 464 /**
 465  * g_resolver_lookup_by_address_finish:
 466  * @resolver: a #GResolver
 467  * @result: the result passed to your #GAsyncReadyCallback
 468  * @error: return location for a #GError, or %NULL
 469  *
 470  * Retrieves the result of a previous call to
 471  * g_resolver_lookup_by_address_async().
 472  *
 473  * If the DNS resolution failed, @error (if non-%NULL) will be set to
 474  * a value from #GResolverError. If the operation was cancelled,
 475  * @error will be set to %G_IO_ERROR_CANCELLED.
 476  *
 477  * Return value: a hostname (either ASCII-only, or in ASCII-encoded
 478  * form), or %NULL on error.
 479  *
 480  * Since: 2.22
 481  */
 482 gchar *
 483 g_resolver_lookup_by_address_finish (GResolver     *resolver,
 484                                      GAsyncResult  *result,
 485                                      GError       **error)
 486 {
 487   g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
 488
 489   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 490     {
 491       GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
 492
 493       if (g_simple_async_result_propagate_error (simple, error))
 494         return NULL;
 495     }
 496
 497   return G_RESOLVER_GET_CLASS (resolver)->
 498     lookup_by_address_finish (resolver, result, error);
 499 }
 500
 501 static gchar *
 502 g_resolver_get_service_rrname (const char *service,
 503                                const char *protocol,
 504                                const char *domain)
 505 {
 506   gchar *rrname, *ascii_domain = NULL;
 507
 508   if (g_hostname_is_non_ascii (domain))
 509     domain = ascii_domain = g_hostname_to_ascii (domain);
 510
 511   rrname = g_strdup_printf ("_%s._%s.%s", service, protocol, domain);
 512
 513   g_free (ascii_domain);
 514   return rrname;
 515 }
 516
 517 /**
 518  * g_resolver_lookup_service:
 519  * @resolver: a #GResolver
 520  * @service: the service type to look up (eg, "ldap")
 521  * @protocol: the networking protocol to use for @service (eg, "tcp")
 522  * @domain: the DNS domain to look up the service in
 523  * @cancellable: a #GCancellable, or %NULL
 524  * @error: return location for a #GError, or %NULL
 525  *
 526  * Synchronously performs a DNS SRV lookup for the given @service and
 527  * @protocol in the given @domain and returns an array of #GSrvTarget.
 528  * @domain may be an ASCII-only or UTF-8 hostname. Note also that the
 529  * @service and @protocol arguments <emphasis>do not</emphasis>
 530  * include the leading underscore that appears in the actual DNS
 531  * entry.
 532  *
 533  * On success, g_resolver_lookup_service() will return a #GList of
 534  * #GSrvTarget, sorted in order of preference. (That is, you should
 535  * attempt to connect to the first target first, then the second if
 536  * the first fails, etc.)
 537  *
 538  * If the DNS resolution fails, @error (if non-%NULL) will be set to
 539  * a value from #GResolverError.
 540  *
 541  * If @cancellable is non-%NULL, it can be used to cancel the
 542  * operation, in which case @error (if non-%NULL) will be set to
 543  * %G_IO_ERROR_CANCELLED.
 544  *
 545  * If you are planning to connect to the service, it is usually easier
 546  * to create a #GNetworkService and use its #GSocketConnectable
 547  * interface.
 548  *
 549  * Return value: a #GList of #GSrvTarget, or %NULL on error. You must
 550  * free each of the targets and the list when you are done with it.
 551  * (You can use g_resolver_free_targets() to do this.)
 552  *
 553  * Since: 2.22
 554  */
 555 GList *
 556 g_resolver_lookup_service (GResolver     *resolver,
 557                            const gchar   *service,
 558                            const gchar   *protocol,
 559                            const gchar   *domain,
 560                            GCancellable  *cancellable,
 561                            GError       **error)
 562 {
 563   GList *targets;
 564   gchar *rrname;
 565
 566   g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
 567   g_return_val_if_fail (service != NULL, NULL);
 568   g_return_val_if_fail (protocol != NULL, NULL);
 569   g_return_val_if_fail (domain != NULL, NULL);
 570
 571   rrname = g_resolver_get_service_rrname (service, protocol, domain);
 572
 573   g_resolver_maybe_reload (resolver);
 574   targets = G_RESOLVER_GET_CLASS (resolver)->
 575     lookup_service (resolver, rrname, cancellable, error);
 576
 577   g_free (rrname);
 578   return targets;
 579 }
 580
 581 /**
 582  * g_resolver_lookup_service_async:
 583  * @resolver: a #GResolver
 584  * @service: the service type to look up (eg, "ldap")
 585  * @protocol: the networking protocol to use for @service (eg, "tcp")
 586  * @domain: the DNS domain to look up the service in
 587  * @cancellable: a #GCancellable, or %NULL
 588  * @callback: callback to call after resolution completes
 589  * @user_data: data for @callback
 590  *
 591  * Begins asynchronously performing a DNS SRV lookup for the given
 592  * @service and @protocol in the given @domain, and eventually calls
 593  * @callback, which must call g_resolver_lookup_service_finish() to
 594  * get the final result. See g_resolver_lookup_service() for more
 595  * details.
 596  *
 597  * Since: 2.22
 598  */
 599 void
 600 g_resolver_lookup_service_async (GResolver           *resolver,
 601                                  const gchar         *service,
 602                                  const gchar         *protocol,
 603                                  const gchar         *domain,
 604                                  GCancellable        *cancellable,
 605                                  GAsyncReadyCallback  callback,
 606                                  gpointer             user_data)
 607 {
 608   gchar *rrname;
 609
 610   g_return_if_fail (G_IS_RESOLVER (resolver));
 611   g_return_if_fail (service != NULL);
 612   g_return_if_fail (protocol != NULL);
 613   g_return_if_fail (domain != NULL);
 614
 615   rrname = g_resolver_get_service_rrname (service, protocol, domain);
 616
 617   g_resolver_maybe_reload (resolver);
 618   G_RESOLVER_GET_CLASS (resolver)->
 619     lookup_service_async (resolver, rrname, cancellable, callback, user_data);
 620
 621   g_free (rrname);
 622 }
 623
 624 /**
 625  * g_resolver_lookup_service_finish:
 626  * @resolver: a #GResolver
 627  * @result: the result passed to your #GAsyncReadyCallback
 628  * @error: return location for a #GError, or %NULL
 629  *
 630  * Retrieves the result of a previous call to
 631  * g_resolver_lookup_service_async().
 632  *
 633  * If the DNS resolution failed, @error (if non-%NULL) will be set to
 634  * a value from #GResolverError. If the operation was cancelled,
 635  * @error will be set to %G_IO_ERROR_CANCELLED.
 636  *
 637  * Return value: a #GList of #GSrvTarget, or %NULL on error. See
 638  * g_resolver_lookup_service() for more details.
 639  *
 640  * Since: 2.22
 641  */
 642 GList *
 643 g_resolver_lookup_service_finish (GResolver     *resolver,
 644                                   GAsyncResult  *result,
 645                                   GError       **error)
 646 {
 647   g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
 648
 649   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 650     {
 651       GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
 652
 653       if (g_simple_async_result_propagate_error (simple, error))
 654         return NULL;
 655     }
 656
 657   return G_RESOLVER_GET_CLASS (resolver)->
 658     lookup_service_finish (resolver, result, error);
 659 }
 660
 661 /**
 662  * g_resolver_free_targets:
 663  * @targets: a #GList of #GSrvTarget
 664  *
 665  * Frees @targets (which should be the return value from
 666  * g_resolver_lookup_service() or g_resolver_lookup_service_finish()).
 667  * (This is a convenience method; you can also simply free the
 668  * results by hand.)
 669  *
 670  * Since: 2.22
 671  */
 672 void
 673 g_resolver_free_targets (GList *targets)
 674 {
 675   GList *t;
 676
 677   for (t = targets; t; t = t->next)
 678     g_srv_target_free (t->data);
 679   g_list_free (targets);
 680 }
 681
 682 /**
 683  * g_resolver_error_quark:
 684  *
 685  * Gets the #GResolver Error Quark.
 686  *
 687  * Return value: a #GQuark.
 688  *
 689  * Since: 2.22
 690  */
 691 GQuark
 692 g_resolver_error_quark (void)
 693 {
 694   return g_quark_from_static_string ("g-resolver-error-quark");
 695 }
 696
 697
 698 static GResolverError
 699 g_resolver_error_from_addrinfo_error (gint err)
 700 {
 701   switch (err)
 702     {
 703     case EAI_FAIL:
 704 #if defined(EAI_NODATA) && (EAI_NODATA != EAI_NONAME)
 705     case EAI_NODATA:
 706 #endif
 707     case EAI_NONAME:
 708       return G_RESOLVER_ERROR_NOT_FOUND;
 709
 710     case EAI_AGAIN:
 711       return G_RESOLVER_ERROR_TEMPORARY_FAILURE;
 712
 713     default:
 714       return G_RESOLVER_ERROR_INTERNAL;
 715     }
 716 }
 717
 718 struct addrinfo _g_resolver_addrinfo_hints;
 719
 720 /* Private method to process a getaddrinfo() response. */
 721 GList *
 722 _g_resolver_addresses_from_addrinfo (const char       *hostname,
 723                                      struct addrinfo  *res,
 724                                      gint              gai_retval,
 725                                      GError          **error)
 726 {
 727   struct addrinfo *ai;
 728   GSocketAddress *sockaddr;
 729   GInetAddress *addr;
 730   GList *addrs;
 731
 732   if (gai_retval != 0)
 733     {
 734       g_set_error (error, G_RESOLVER_ERROR,
 735                    g_resolver_error_from_addrinfo_error (gai_retval),
 736                    _("Error resolving '%s': %s"),
 737                    hostname, gai_strerror (gai_retval));
 738       return NULL;
 739     }
 740
 741   g_return_val_if_fail (res != NULL, NULL);
 742
 743   addrs = NULL;
 744   for (ai = res; ai; ai = ai->ai_next)
 745     {
 746       sockaddr = g_socket_address_new_from_native (ai->ai_addr, ai->ai_addrlen);
 747       if (!sockaddr || !G_IS_INET_SOCKET_ADDRESS (sockaddr))
 748         continue;
 749
 750       addr = g_object_ref (g_inet_socket_address_get_address ((GInetSocketAddress *)sockaddr));
 751       addrs = g_list_prepend (addrs, addr);
 752       g_object_unref (sockaddr);
 753     }
 754
 755   return g_list_reverse (addrs);
 756 }
 757
 758 /* Private method to set up a getnameinfo() request */
 759 void
 760 _g_resolver_address_to_sockaddr (GInetAddress            *address,
 761                                  struct sockaddr_storage *sa,
 762                                  gsize                   *len)
 763 {
 764   GSocketAddress *sockaddr;
 765
 766   sockaddr = g_inet_socket_address_new (address, 0);
 767   g_socket_address_to_native (sockaddr, (struct sockaddr *)sa, sizeof (*sa), NULL);
 768   *len = g_socket_address_get_native_size (sockaddr);
 769   g_object_unref (sockaddr);
 770 }
 771
 772 /* Private method to process a getnameinfo() response. */
 773 char *
 774 _g_resolver_name_from_nameinfo (GInetAddress  *address,
 775                                 const gchar   *name,
 776                                 gint           gni_retval,
 777                                 GError       **error)
 778 {
 779   if (gni_retval != 0)
 780     {
 781       gchar *phys;
 782
 783       phys = g_inet_address_to_string (address);
 784       g_set_error (error, G_RESOLVER_ERROR,
 785                    g_resolver_error_from_addrinfo_error (gni_retval),
 786                    _("Error reverse-resolving '%s': %s"),
 787                    phys ? phys : "(unknown)", gai_strerror (gni_retval));
 788       g_free (phys);
 789       return NULL;
 790     }
 791
 792   return g_strdup (name);
 793 }
 794
 795 #if defined(G_OS_UNIX)
 796 /* Private method to process a res_query response into GSrvTargets */
 797 GList *
 798 _g_resolver_targets_from_res_query (const gchar      *rrname,
 799                                     guchar           *answer,
 800                                     gint              len,
 801                                     gint              herr,
 802                                     GError          **error)
 803 {
 804   gint count;
 805   gchar namebuf[1024];
 806   guchar *end, *p;
 807   guint16 type, qclass, rdlength, priority, weight, port;
 808   guint32 ttl;
 809   HEADER *header;
 810   GSrvTarget *target;
 811   GList *targets;
 812
 813   if (len <= 0)
 814     {
 815       GResolverError errnum;
 816       const gchar *format;
 817
 818       if (len == 0 || herr == HOST_NOT_FOUND || herr == NO_DATA)
 819         {
 820           errnum = G_RESOLVER_ERROR_NOT_FOUND;
 821           format = _("No service record for '%s'");
 822         }
 823       else if (herr == TRY_AGAIN)
 824         {
 825           errnum = G_RESOLVER_ERROR_TEMPORARY_FAILURE;
 826           format = _("Temporarily unable to resolve '%s'");
 827         }
 828       else
 829         {
 830           errnum = G_RESOLVER_ERROR_INTERNAL;
 831           format = _("Error resolving '%s'");
 832         }
 833
 834       g_set_error (error, G_RESOLVER_ERROR, errnum, format, rrname);
 835       return NULL;
 836     }
 837
 838   targets = NULL;
 839
 840   header = (HEADER *)answer;
 841   p = answer + sizeof (HEADER);
 842   end = answer + len;
 843
 844   /* Skip query */
 845   count = ntohs (header->qdcount);
 846   while (count-- && p < end)
 847     {
 848       p += dn_expand (answer, end, p, namebuf, sizeof (namebuf));
 849       p += 4;
 850     }
 851
 852   /* Read answers */
 853   count = ntohs (header->ancount);
 854   while (count-- && p < end)
 855     {
 856       p += dn_expand (answer, end, p, namebuf, sizeof (namebuf));
 857       GETSHORT (type, p);
 858       GETSHORT (qclass, p);
 859       GETLONG  (ttl, p);
 860       GETSHORT (rdlength, p);
 861
 862       if (type != T_SRV || qclass != C_IN)
 863         {
 864           p += rdlength;
 865           continue;
 866         }
 867
 868       GETSHORT (priority, p);
 869       GETSHORT (weight, p);
 870       GETSHORT (port, p);
 871       p += dn_expand (answer, end, p, namebuf, sizeof (namebuf));
 872
 873       target = g_srv_target_new (namebuf, port, priority, weight);
 874       targets = g_list_prepend (targets, target);
 875     }
 876
 877   return g_srv_target_list_sort (targets);
 878 }
 879 #elif defined(G_OS_WIN32)
 880 /* Private method to process a DnsQuery response into GSrvTargets */
 881 GList *
 882 _g_resolver_targets_from_DnsQuery (const gchar  *rrname,
 883                                    DNS_STATUS    status,
 884                                    DNS_RECORD   *results,
 885                                    GError      **error)
 886 {
 887   DNS_RECORD *rec;
 888   GSrvTarget *target;
 889   GList *targets;
 890
 891   if (status != ERROR_SUCCESS)
 892     {
 893       GResolverError errnum;
 894       const gchar *format;
 895
 896       if (status == DNS_ERROR_RCODE_NAME_ERROR)
 897         {
 898           errnum = G_RESOLVER_ERROR_NOT_FOUND;
 899           format = _("No service record for '%s'");
 900         }
 901       else if (status == DNS_ERROR_RCODE_SERVER_FAILURE)
 902         {
 903           errnum = G_RESOLVER_ERROR_TEMPORARY_FAILURE;
 904           format = _("Temporarily unable to resolve '%s'");
 905         }
 906       else
 907         {
 908           errnum = G_RESOLVER_ERROR_INTERNAL;
 909           format = _("Error resolving '%s'");
 910         }
 911
 912       g_set_error (error, G_RESOLVER_ERROR, errnum, format, rrname);
 913       return NULL;
 914     }
 915
 916   targets = NULL;
 917   for (rec = results; rec; rec = rec->pNext)
 918     {
 919       if (rec->wType != DNS_TYPE_SRV)
 920         continue;
 921
 922       target = g_srv_target_new (rec->Data.SRV.pNameTarget,
 923                                  rec->Data.SRV.wPort,
 924                                  rec->Data.SRV.wPriority,
 925                                  rec->Data.SRV.wWeight);
 926       targets = g_list_prepend (targets, target);
 927     }
 928
 929   return g_srv_target_list_sort (targets);
 930 }
 931
 932 #endif
 933
 934 #define __G_RESOLVER_C__
 935 #include "gioaliasdef.c"