gio/gwin32resolver.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 <stdio.h>
  28 #include <string.h>
  29
  30 #include "gwin32resolver.h"
  31 #include "gnetworkingprivate.h"
  32
  33 #include "gcancellable.h"
  34 #include "gsimpleasyncresult.h"
  35 #include "gsocketaddress.h"
  36
  37 #include "gioalias.h"
  38
  39 G_DEFINE_TYPE (GWin32Resolver, g_win32_resolver, G_TYPE_THREADED_RESOLVER)
  40
  41 static void
  42 g_win32_resolver_init (GWin32Resolver *gwr)
  43 {
  44 }
  45
  46 /* This is simpler than GThreadedResolver since we don't have to worry
  47  * about multiple application-level threads, but more complicated than
  48  * GUnixResolver, since we do have to deal with multiple threads of
  49  * our own.
  50  *
  51  * The various request possibilities:
  52  *
  53  * 1. Synchronous: handed off to the base class (GThreadedResolver);
  54  *    since it's never possible to cancel a synchronous request in a
  55  *    single-threaded program, the request is done in the calling
  56  *    thread.
  57  *
  58  * 2. Asynchronous: A GWin32ResolverRequest is created with
  59  *    appropriate query-specific information, a Windows event handle,
  60  *    and a GSimpleAsyncResult. This is then handed to the
  61  *    Windows-internal thread pool, which does the raw DNS query part
  62  *    of the operation (being careful to not call any glib methods
  63  *    that might fail when called from another thread when
  64  *    g_thread_init() has not been called). The main thread sets up a
  65  *    GSource to asynchronously poll the event handle. There are two
  66  *    sub-possibilities:
  67  *
  68  *      a. The resolution completes: the threadpool function calls
  69  *         SetEvent() on the event handle and then returns.
  70  *
  71  *      b. The resolution is cancelled: request_cancelled()
  72  *         disconnects the "cancelled" signal handler, and queues an
  73  *         idle handler to complete the async_result.
  74  *
  75  *    Since we can't free the request from the threadpool thread
  76  *    (because of glib locking issues), we *always* have to have it
  77  *    call SetEvent and trigger the callback to indicate that it is
  78  *    done. But this means that it's possible for the request to be
  79  *    cancelled (queuing an idle handler to return that result) and
  80  *    then have the resolution thread complete before the idle handler
  81  *    runs. So the event callback and the idle handler need to both
  82  *    watch out for this, making sure we don't complete the same
  83  *    result twice.
  84  */
  85
  86 typedef struct GWin32ResolverRequest GWin32ResolverRequest;
  87 typedef void (*GWin32ResolverRequestFreeFunc) (GWin32ResolverRequest *);
  88
  89 struct GWin32ResolverRequest {
  90   GWin32ResolverRequestFreeFunc free_func;
  91
  92   GCancellable *cancellable;
  93   GError *error;
  94
  95   HANDLE *event;
  96   GSimpleAsyncResult *async_result;
  97   gboolean complete;
  98   guint cancelled_idle;
  99
 100   union {
 101     struct {
 102       gchar *name;
 103       gint retval;
 104       struct addrinfo *res;
 105     } name;
 106
 107     struct {
 108       GInetAddress *iaddr;
 109       struct sockaddr_storage addr;
 110       gsize addrlen;
 111       gint retval;
 112       gchar *namebuf;
 113     } address;
 114
 115     struct {
 116       gchar *rrname;
 117       DNS_STATUS retval;
 118       DNS_RECORD *results;
 119     } service;
 120   } u;
 121
 122 };
 123
 124 static GSource *g_win32_handle_source_add (HANDLE      handle,
 125                                            GSourceFunc callback,
 126                                            gpointer    user_data);
 127
 128 static gboolean request_completed (gpointer      user_data);
 129 static void     request_cancelled (GCancellable *cancellable,
 130                                    gpointer      user_data);
 131
 132 GWin32ResolverRequest *
 133 g_win32_resolver_request_new (GResolver                     *resolver,
 134                               GWin32ResolverRequestFreeFunc  free_func,
 135                               GCancellable                  *cancellable,
 136                               GAsyncReadyCallback            callback,
 137                               gpointer                       user_data,
 138                               gpointer                       tag)
 139 {
 140   GWin32ResolverRequest *req;
 141
 142   req = g_slice_new0 (GWin32ResolverRequest);
 143   req->free_func = free_func;
 144
 145   req->async_result = g_simple_async_result_new (G_OBJECT (resolver), callback,
 146                                                  user_data, tag);
 147   g_simple_async_result_set_op_res_gpointer (req->async_result, req, NULL);
 148
 149   req->event = CreateEvent (NULL, FALSE, FALSE, NULL);
 150   g_win32_handle_source_add (req->event, request_completed, req);
 151
 152   if (cancellable)
 153     {
 154       req->cancellable = g_object_ref (cancellable);
 155       g_signal_connect (cancellable, "cancelled",
 156                         G_CALLBACK (request_cancelled), req);
 157     }
 158
 159   return req;
 160 }
 161
 162 static gboolean
 163 request_completed (gpointer user_data)
 164 {
 165   GWin32ResolverRequest *req = user_data;
 166
 167   /* Clean up cancellation-related stuff first */
 168   if (req->cancelled_idle)
 169     {
 170       g_source_remove (req->cancelled_idle);
 171       req->cancelled_idle = 0;
 172     }
 173   if (req->cancellable)
 174     {
 175       g_signal_handlers_disconnect_by_func (req->cancellable, request_cancelled, req);
 176       g_object_unref (req->cancellable);
 177     }
 178
 179   /* Now complete the result (assuming it wasn't already completed) */
 180   if (req->async_result)
 181     {
 182       g_simple_async_result_complete (req->async_result);
 183       g_object_unref (req->async_result);
 184     }
 185
 186   /* And free req */
 187   CloseHandle (req->event);
 188   req->free_func (req);
 189   g_slice_free (GWin32ResolverRequest, req);
 190
 191   return FALSE;
 192 }
 193
 194 static gboolean
 195 request_cancelled_idle (gpointer user_data)
 196 {
 197   GWin32ResolverRequest *req = user_data;
 198   GError *error = NULL;
 199
 200   req->cancelled_idle = 0;
 201
 202   g_cancellable_set_error_if_cancelled (req->cancellable, &error);
 203   g_simple_async_result_set_from_error (req->async_result, error);
 204   g_simple_async_result_complete (req->async_result);
 205
 206   g_object_unref (req->async_result);
 207   req->async_result = NULL;
 208
 209   /* request_completed will eventually be called to free req */
 210
 211   return FALSE;
 212 }
 213
 214 static void
 215 request_cancelled (GCancellable *cancellable,
 216                    gpointer      user_data)
 217 {
 218   GWin32ResolverRequest *req = user_data;
 219
 220   if (req->cancellable)
 221     {
 222       g_signal_handlers_disconnect_by_func (req->cancellable, request_cancelled, req);
 223       g_object_unref (req->cancellable);
 224       req->cancellable = NULL;
 225     }
 226
 227   /* We need to wait until main-loop-time to actually complete the
 228    * result; we don't use _complete_in_idle() here because we need to
 229    * keep track of the source id.
 230    */
 231   req->cancelled_idle = g_idle_add (request_cancelled_idle, req);
 232 }
 233
 234 static DWORD WINAPI
 235 lookup_by_name_in_thread (LPVOID data)
 236 {
 237   GWin32ResolverRequest *req = data;
 238
 239   req->u.name.retval = getaddrinfo (req->u.name.name, NULL,
 240                                     &_g_resolver_addrinfo_hints,
 241                                     &req->u.name.res);
 242   SetEvent (req->event);
 243   return 0;
 244 }
 245
 246 static void
 247 free_lookup_by_name (GWin32ResolverRequest *req)
 248 {
 249   g_free (req->u.name.name);
 250   if (req->u.name.res)
 251     freeaddrinfo (req->u.name.res);
 252 }
 253
 254 static void
 255 lookup_by_name_async (GResolver           *resolver,
 256                       const gchar         *hostname,
 257                       GCancellable        *cancellable,
 258                       GAsyncReadyCallback  callback,
 259                       gpointer             user_data)
 260 {
 261   GWin32ResolverRequest *req;
 262
 263   req = g_win32_resolver_request_new (resolver, free_lookup_by_name,
 264                                       cancellable, callback, user_data,
 265                                       lookup_by_name_async);
 266   req->u.name.name = g_strdup (hostname);
 267
 268   QueueUserWorkItem (lookup_by_name_in_thread, req, 0);
 269 }
 270
 271 static GList *
 272 lookup_by_name_finish (GResolver     *resolver,
 273                        GAsyncResult  *result,
 274                        GError       **error)
 275 {
 276   GSimpleAsyncResult *simple;
 277   GWin32ResolverRequest *req;
 278
 279   g_return_val_if_fail (g_simple_async_result_is_valid (result, G_OBJECT (resolver), lookup_by_name_async), NULL);
 280   simple = G_SIMPLE_ASYNC_RESULT (result);
 281
 282   req = g_simple_async_result_get_op_res_gpointer (simple);
 283   return _g_resolver_addresses_from_addrinfo (req->u.name.name, req->u.name.res,
 284                                               req->u.name.retval, error);
 285 }
 286
 287
 288 static DWORD WINAPI
 289 lookup_by_addresses_in_thread (LPVOID data)
 290 {
 291   GWin32ResolverRequest *req = data;
 292
 293   req->u.address.retval =
 294     getnameinfo ((struct sockaddr *)&req->u.address.addr,
 295                  req->u.address.addrlen,
 296                  req->u.address.namebuf, NI_MAXHOST, NULL, 0, NI_NAMEREQD);
 297   SetEvent (req->event);
 298   return 0;
 299 }
 300
 301 static void
 302 free_lookup_by_address (GWin32ResolverRequest *req)
 303 {
 304   g_object_unref (req->u.address.iaddr);
 305   g_free (req->u.address.namebuf);
 306 }
 307
 308 static void
 309 lookup_by_address_async (GResolver           *resolver,
 310                          GInetAddress        *address,
 311                          GCancellable        *cancellable,
 312                          GAsyncReadyCallback  callback,
 313                          gpointer             user_data)
 314 {
 315   GWin32ResolverRequest *req;
 316
 317   req = g_win32_resolver_request_new (resolver, free_lookup_by_address,
 318                                       cancellable, callback, user_data,
 319                                       lookup_by_address_async);
 320
 321   req->u.address.iaddr = g_object_ref (address);
 322   _g_resolver_address_to_sockaddr (address, &req->u.address.addr,
 323                                    &req->u.address.addrlen);
 324   req->u.address.namebuf = g_malloc (NI_MAXHOST);
 325
 326   QueueUserWorkItem (lookup_by_addresses_in_thread, req, 0);
 327 }
 328
 329 static char *
 330 lookup_by_address_finish (GResolver     *resolver,
 331                           GAsyncResult  *result,
 332                           GError       **error)
 333 {
 334   GSimpleAsyncResult *simple;
 335   GWin32ResolverRequest *req;
 336
 337   g_return_val_if_fail (g_simple_async_result_is_valid (result, G_OBJECT (resolver), lookup_by_address_async), NULL);
 338   simple = G_SIMPLE_ASYNC_RESULT (result);
 339
 340   req = g_simple_async_result_get_op_res_gpointer (simple);
 341   return _g_resolver_name_from_nameinfo (req->u.address.iaddr,
 342                                          req->u.address.namebuf,
 343                                          req->u.address.retval, error);
 344 }
 345
 346
 347 static DWORD WINAPI
 348 lookup_service_in_thread (LPVOID data)
 349 {
 350   GWin32ResolverRequest *req = data;
 351
 352   req->u.service.retval =
 353     DnsQuery_A (req->u.service.rrname, DNS_TYPE_SRV, DNS_QUERY_STANDARD,
 354                 NULL, &req->u.service.results, NULL);
 355   SetEvent (req->event);
 356   return 0;
 357 }
 358
 359 static void
 360 free_lookup_service (GWin32ResolverRequest *req)
 361 {
 362   g_free (req->u.service.rrname);
 363   if (req->u.service.results)
 364     DnsRecordListFree (req->u.service.results, DnsFreeRecordList);
 365 }
 366
 367 static void
 368 lookup_service_async (GResolver           *resolver,
 369                       const char          *rrname,
 370                       GCancellable        *cancellable,
 371                       GAsyncReadyCallback  callback,
 372                       gpointer             user_data)
 373 {
 374   GWin32ResolverRequest *req;
 375
 376   req = g_win32_resolver_request_new (resolver, free_lookup_service,
 377                                       cancellable, callback, user_data,
 378                                       lookup_service_async);
 379   req->u.service.rrname = g_strdup (rrname);
 380
 381   QueueUserWorkItem (lookup_service_in_thread, req, 0);
 382 }
 383
 384 static GList *
 385 lookup_service_finish (GResolver     *resolver,
 386                        GAsyncResult  *result,
 387                        GError       **error)
 388 {
 389   GSimpleAsyncResult *simple;
 390   GWin32ResolverRequest *req;
 391
 392   g_return_val_if_fail (g_simple_async_result_is_valid (result, G_OBJECT (resolver), lookup_service_async), NULL);
 393   simple = G_SIMPLE_ASYNC_RESULT (result);
 394
 395   req = g_simple_async_result_get_op_res_gpointer (simple);
 396   return _g_resolver_targets_from_DnsQuery (req->u.service.rrname,
 397                                             req->u.service.retval,
 398                                             req->u.service.results, error);
 399 }
 400
 401
 402 static void
 403 g_win32_resolver_class_init (GWin32ResolverClass *win32_class)
 404 {
 405   GResolverClass *resolver_class = G_RESOLVER_CLASS (win32_class);
 406
 407   resolver_class->lookup_by_name_async     = lookup_by_name_async;
 408   resolver_class->lookup_by_name_finish    = lookup_by_name_finish;
 409   resolver_class->lookup_by_address_async  = lookup_by_address_async;
 410   resolver_class->lookup_by_address_finish = lookup_by_address_finish;
 411   resolver_class->lookup_service_async     = lookup_service_async;
 412   resolver_class->lookup_service_finish    = lookup_service_finish;
 413 }
 414
 415
 416 /* Windows HANDLE GSource */
 417
 418 typedef struct {
 419   GSource source;
 420   GPollFD pollfd;
 421 } GWin32HandleSource;
 422
 423 static gboolean
 424 g_win32_handle_source_prepare (GSource *source,
 425                                gint    *timeout)
 426 {
 427   *timeout = -1;
 428   return FALSE;
 429 }
 430
 431 static gboolean
 432 g_win32_handle_source_check (GSource *source)
 433 {
 434   GWin32HandleSource *hsource = (GWin32HandleSource *)source;
 435
 436   return hsource->pollfd.revents;
 437 }
 438
 439 static gboolean
 440 g_win32_handle_source_dispatch (GSource     *source,
 441                                 GSourceFunc  callback,
 442                                 gpointer     user_data)
 443 {
 444   return (*callback) (user_data);
 445 }
 446
 447 static void
 448 g_win32_handle_source_finalize (GSource *source)
 449 {
 450   ;
 451 }
 452
 453 GSourceFuncs g_win32_handle_source_funcs = {
 454   g_win32_handle_source_prepare,
 455   g_win32_handle_source_check,
 456   g_win32_handle_source_dispatch,
 457   g_win32_handle_source_finalize
 458 };
 459
 460 static GSource *
 461 g_win32_handle_source_add (HANDLE      handle,
 462                            GSourceFunc callback,
 463                            gpointer    user_data)
 464 {
 465   GWin32HandleSource *hsource;
 466   GSource *source;
 467
 468   source = g_source_new (&g_win32_handle_source_funcs, sizeof (GWin32HandleSource));
 469   hsource = (GWin32HandleSource *)source;
 470   hsource->pollfd.fd = (gint)handle;
 471   hsource->pollfd.events = G_IO_IN;
 472   hsource->pollfd.revents = 0;
 473   g_source_add_poll (source, &hsource->pollfd);
 474
 475   g_source_set_callback (source, callback, user_data, NULL);
 476   g_source_attach (source, NULL);
 477   return source;
 478 }
 479
 480 #define __G_WIN32_RESOLVER_C__
 481 #include "gioaliasdef.c"