droute/droute.c

   1 /*
   2  * AT-SPI - Assistive Technology Service Provider Interface
   3  * (Gnome Accessibility Project; http://developer.gnome.org/projects/gap)
   4  *
   5  * Copyright 2008 Novell, Inc.
   6  * Copyright 2008 Codethink Ltd.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Library General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Library General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Library General Public
  19  * License along with this library; if not, write to the
  20  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  21  * Boston, MA 02111-1307, USA.
  22  */
  23
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27
  28 #include "droute.h"
  29 #include "droute-pairhash.h"
  30
  31 #define CHUNKS_DEFAULT (512)
  32
  33 #define oom() g_error ("D-Bus out of memory, this message will fail anyway")
  34
  35 #if defined DROUTE_DEBUG
  36     #define _DROUTE_DEBUG(format, args...) g_print (format , ## args)
  37 #else
  38     #define _DROUTE_DEBUG(format, args...)
  39 #endif
  40
  41 struct _DRouteContext
  42 {
  43     GPtrArray            *registered_paths;
  44
  45     gchar                *introspect_string;
  46 };
  47
  48 struct _DRoutePath
  49 {
  50     DRouteContext        *cnx;
  51     gchar *path;
  52     gboolean prefix;
  53     GStringChunk         *chunks;
  54     GPtrArray            *interfaces;
  55     GPtrArray            *introspection;
  56     GHashTable           *methods;
  57     GHashTable           *properties;
  58
  59     DRouteIntrospectChildrenFunction introspect_children_cb;
  60     void *introspect_children_data;
  61     void                   *user_data;
  62     DRouteGetDatumFunction  get_datum;
  63 };
  64
  65 /*---------------------------------------------------------------------------*/
  66
  67 typedef struct PropertyPair
  68 {
  69     DRoutePropertyFunction get;
  70     DRoutePropertyFunction set;
  71 } PropertyPair;
  72
  73 /*---------------------------------------------------------------------------*/
  74
  75 static DBusHandlerResult
  76 handle_message (DBusConnection *bus, DBusMessage *message, void *user_data);
  77
  78 static DBusMessage *
  79 droute_object_does_not_exist_error (DBusMessage *message);
  80
  81 /*---------------------------------------------------------------------------*/
  82
  83 static DRoutePath *
  84 path_new (DRouteContext *cnx,
  85           const char *path,
  86           gboolean prefix,
  87           void    *user_data,
  88           DRouteIntrospectChildrenFunction introspect_children_cb,
  89           void *introspect_children_data,
  90           DRouteGetDatumFunction get_datum)
  91 {
  92     DRoutePath *new_path;
  93
  94     new_path = g_new0 (DRoutePath, 1);
  95     new_path->cnx = cnx;
  96     new_path->path = g_strdup (path);
  97     new_path->prefix = prefix;
  98     new_path->chunks = g_string_chunk_new (CHUNKS_DEFAULT);
  99     new_path->interfaces = g_ptr_array_new ();
 100     new_path->introspection = g_ptr_array_new ();
 101
 102     new_path->methods = g_hash_table_new_full ((GHashFunc)str_pair_hash,
 103                                                str_pair_equal,
 104                                                g_free,
 105                                                NULL);
 106
 107     new_path->properties = g_hash_table_new_full ((GHashFunc)str_pair_hash,
 108                                                   str_pair_equal,
 109                                                   g_free,
 110                                                   NULL);
 111
 112     new_path->introspect_children_cb = introspect_children_cb;
 113     new_path->introspect_children_data = introspect_children_data;
 114     new_path->user_data = user_data;
 115     new_path->get_datum = get_datum;
 116
 117     return new_path;
 118 }
 119
 120 static void
 121 path_free (DRoutePath *path, gpointer user_data)
 122 {
 123     g_free (path->path);
 124     g_string_chunk_free  (path->chunks);
 125     g_ptr_array_free     (path->interfaces, TRUE);
 126     g_ptr_array_free     (path->introspection, FALSE);
 127     g_hash_table_destroy (path->methods);
 128     g_hash_table_destroy (path->properties);
 129 }
 130
 131 static void *
 132 path_get_datum (DRoutePath *path, const gchar *pathstr)
 133 {
 134     if (path->get_datum != NULL)
 135         return (path->get_datum) (pathstr, path->user_data);
 136     else
 137         return path->user_data;
 138 }
 139
 140 /*---------------------------------------------------------------------------*/
 141
 142 DRouteContext *
 143 droute_new ()
 144 {
 145     DRouteContext *cnx;
 146
 147     cnx = g_new0 (DRouteContext, 1);
 148     cnx->registered_paths = g_ptr_array_new ();
 149
 150     return cnx;
 151 }
 152
 153 void
 154 droute_free (DRouteContext *cnx)
 155 {
 156     g_ptr_array_foreach (cnx->registered_paths, (GFunc) path_free, NULL);
 157     g_free (cnx);
 158 }
 159
 160 /*---------------------------------------------------------------------------*/
 161
 162 /*---------------------------------------------------------------------------*/
 163
 164 static DBusObjectPathVTable droute_vtable =
 165 {
 166   NULL,
 167   &handle_message,
 168   NULL, NULL, NULL, NULL
 169 };
 170
 171 DRoutePath *
 172 droute_add_one (DRouteContext *cnx,
 173                 const char    *path,
 174                 const void    *data)
 175 {
 176     DRoutePath *new_path;
 177     gboolean registered;
 178
 179     new_path = path_new (cnx, path, FALSE, (void *)data, NULL, NULL, NULL);
 180
 181     g_ptr_array_add (cnx->registered_paths, new_path);
 182     return new_path;
 183 }
 184
 185 DRoutePath *
 186 droute_add_many (DRouteContext *cnx,
 187                  const char    *path,
 188                  const void    *data,
 189                  DRouteIntrospectChildrenFunction introspect_children_cb,
 190                  void *introspect_children_data,
 191                  const DRouteGetDatumFunction get_datum)
 192 {
 193     DRoutePath *new_path;
 194
 195     new_path = path_new (cnx, path, TRUE, (void *) data,
 196                          introspect_children_cb, introspect_children_data,
 197                          get_datum);
 198
 199     g_ptr_array_add (cnx->registered_paths, new_path);
 200     return new_path;
 201 }
 202
 203 /*---------------------------------------------------------------------------*/
 204
 205 void
 206 droute_path_add_interface(DRoutePath *path,
 207                           const char *name,
 208                           const char *introspect,
 209                           const DRouteMethod   *methods,
 210                           const DRouteProperty *properties)
 211 {
 212     gchar *itf;
 213
 214     g_return_if_fail (name != NULL);
 215
 216     itf = g_string_chunk_insert (path->chunks, name);
 217     g_ptr_array_add (path->interfaces, itf);
 218     g_ptr_array_add (path->introspection, introspect);
 219
 220     for (; methods != NULL && methods->name != NULL; methods++)
 221       {
 222         gchar *meth;
 223
 224         meth = g_string_chunk_insert (path->chunks, methods->name);
 225         g_hash_table_insert (path->methods, str_pair_new (itf, meth), methods->func);
 226       }
 227
 228     for (; properties != NULL && properties->name != NULL; properties++)
 229       {
 230         gchar *prop;
 231         PropertyPair *pair;
 232
 233         prop = g_string_chunk_insert (path->chunks, properties->name);
 234         pair = g_new (PropertyPair, 1);
 235         pair->get = properties->get;
 236         pair->set = properties->set;
 237         g_hash_table_insert (path->properties, str_pair_new (itf, prop), pair);
 238       }
 239 }
 240
 241 /*---------------------------------------------------------------------------*/
 242
 243 /* The data structures don't support an efficient implementation of GetAll
 244  * and I don't really care.
 245  */
 246 static DBusMessage *
 247 impl_prop_GetAll (DBusMessage *message,
 248                   DRoutePath  *path,
 249                   const char  *pathstr)
 250 {
 251     DBusMessageIter iter, iter_dict, iter_dict_entry;
 252     DBusMessage *reply;
 253     DBusError error;
 254     GHashTableIter prop_iter;
 255
 256     StrPair *key;
 257     PropertyPair *value;
 258     gchar *iface;
 259
 260     void  *datum = path_get_datum (path, pathstr);
 261     if (!datum)
 262         return droute_object_does_not_exist_error (message);
 263
 264     dbus_error_init (&error);
 265     if (!dbus_message_get_args
 266                 (message, &error, DBUS_TYPE_STRING, &iface, DBUS_TYPE_INVALID))
 267         return dbus_message_new_error (message, DBUS_ERROR_FAILED, error.message);
 268
 269     reply = dbus_message_new_method_return (message);
 270     if (!reply)
 271         oom ();
 272
 273     dbus_message_iter_init_append (reply, &iter);
 274     if (!dbus_message_iter_open_container
 275                 (&iter, DBUS_TYPE_ARRAY, "{sv}", &iter_dict))
 276         oom ();
 277
 278     g_hash_table_iter_init (&prop_iter, path->properties);
 279     while (g_hash_table_iter_next (&prop_iter, (gpointer*)&key, (gpointer*)&value))
 280       {
 281         if (!g_strcmp0 (key->one, iface))
 282          {
 283            if (!value->get)
 284               continue;
 285            if (!dbus_message_iter_open_container
 286                         (&iter_dict, DBUS_TYPE_DICT_ENTRY, NULL, &iter_dict_entry))
 287               oom ();
 288            dbus_message_iter_append_basic (&iter_dict_entry, DBUS_TYPE_STRING,
 289                                            &key->two);
 290            (value->get) (&iter_dict_entry, datum);
 291            if (!dbus_message_iter_close_container (&iter_dict, &iter_dict_entry))
 292                oom ();
 293          }
 294       }
 295
 296     if (!dbus_message_iter_close_container (&iter, &iter_dict))
 297         oom ();
 298     return reply;
 299 }
 300
 301 static DBusMessage *
 302 impl_prop_GetSet (DBusMessage *message,
 303                   DRoutePath  *path,
 304                   const char  *pathstr,
 305                   gboolean     get)
 306 {
 307     DBusMessage *reply = NULL;
 308     DBusError error;
 309
 310     StrPair pair;
 311     PropertyPair *prop_funcs = NULL;
 312
 313     void *datum;
 314
 315     dbus_error_init (&error);
 316     if (!dbus_message_get_args (message,
 317                                 &error,
 318                                 DBUS_TYPE_STRING,
 319                                 &(pair.one),
 320                                 DBUS_TYPE_STRING,
 321                                 &(pair.two),
 322                                 DBUS_TYPE_INVALID))
 323         return dbus_message_new_error (message, DBUS_ERROR_FAILED, error.message);
 324
 325     _DROUTE_DEBUG ("DRoute (handle prop): %s|%s on %s\n", pair.one, pair.two, pathstr);
 326
 327     prop_funcs = (PropertyPair *) g_hash_table_lookup (path->properties, &pair);
 328     if (!prop_funcs)
 329         return dbus_message_new_error (message, DBUS_ERROR_FAILED, "Property unavailable");
 330
 331     datum = path_get_datum (path, pathstr);
 332     if (!datum)
 333         return droute_object_does_not_exist_error (message);
 334
 335     if (get && prop_funcs->get)
 336       {
 337
 338         DBusMessageIter iter;
 339
 340         _DROUTE_DEBUG ("DRoute (handle prop Get): %s|%s on %s\n", pair.one, pair.two, pathstr);
 341
 342         reply = dbus_message_new_method_return (message);
 343         dbus_message_iter_init_append (reply, &iter);
 344         if (!(prop_funcs->get) (&iter, datum))
 345           {
 346             dbus_message_unref (reply);
 347             reply = dbus_message_new_error (message, DBUS_ERROR_FAILED, "Get failed");
 348           }
 349       }
 350     else if (!get && prop_funcs->set)
 351       {
 352         DBusMessageIter iter;
 353
 354         _DROUTE_DEBUG ("DRoute (handle prop Get): %s|%s on %s\n", pair.one, pair.two, pathstr);
 355
 356         dbus_message_iter_init (message, &iter);
 357         /* Skip the interface and property name */
 358         dbus_message_iter_next(&iter);
 359         dbus_message_iter_next(&iter);
 360         (prop_funcs->set) (&iter, datum);
 361
 362         reply = dbus_message_new_method_return (message);
 363       }
 364     else
 365       {
 366         reply = dbus_message_new_error (message, DBUS_ERROR_FAILED, "Getter or setter unavailable");
 367       }
 368
 369     return reply;
 370 }
 371
 372 static DBusHandlerResult
 373 handle_dbus (DBusConnection *bus,
 374                    DBusMessage    *message,
 375                    const gchar    *iface,
 376                    const gchar    *member,
 377                    const gchar    *pathstr)
 378 {
 379   static int id = 1;
 380   char *id_str = (char *) g_malloc(40);
 381   DBusMessage *reply;
 382
 383     if (strcmp (iface, DBUS_INTERFACE_DBUS) != 0 ||
 384         strcmp (member, "Hello") != 0)
 385     return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 386
 387     /* TODO: Fix this hack (we don't handle wrap-around, for instance) */
 388     sprintf (id_str, ":1.%d", id++);
 389     reply = dbus_message_new_method_return (message);
 390     dbus_message_append_args (reply, DBUS_TYPE_STRING, &id_str, DBUS_TYPE_INVALID);
 391     dbus_connection_send (bus, reply, NULL);
 392   dbus_connection_flush (bus);
 393     dbus_message_unref (reply);
 394   g_free (id_str);
 395     return DBUS_HANDLER_RESULT_HANDLED;
 396 }
 397
 398 static DBusHandlerResult
 399 handle_properties (DBusConnection *bus,
 400                    DBusMessage    *message,
 401                    DRoutePath     *path,
 402                    const gchar    *iface,
 403                    const gchar    *member,
 404                    const gchar    *pathstr)
 405 {
 406     DBusMessage *reply;
 407     DBusHandlerResult result = DBUS_HANDLER_RESULT_HANDLED;
 408
 409     if (!g_strcmp0(member, "GetAll"))
 410        reply = impl_prop_GetAll (message, path, pathstr);
 411     else if (!g_strcmp0 (member, "Get"))
 412        reply = impl_prop_GetSet (message, path, pathstr, TRUE);
 413     else if (!g_strcmp0 (member, "Set"))
 414        reply = impl_prop_GetSet (message, path, pathstr, FALSE);
 415     else
 416        result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 417
 418     if (reply)
 419       {
 420         dbus_connection_send (bus, reply, NULL);
 421         dbus_message_unref (reply);
 422       }
 423
 424     return result;
 425 }
 426
 427 /*---------------------------------------------------------------------------*/
 428
 429 static const char *introspection_header =
 430 "<?xml version=\"1.0\"?>\n";
 431
 432 static const char *introspection_node_element =
 433 "<node name=\"%s\">\n";
 434
 435 static const char *introspection_footer =
 436 "</node>";
 437
 438 static DBusHandlerResult
 439 handle_introspection (DBusConnection *bus,
 440                       DBusMessage    *message,
 441                       DRoutePath     *path,
 442                       const gchar    *iface,
 443                       const gchar    *member,
 444                       const gchar    *pathstr)
 445 {
 446     GString *output;
 447     gchar *final;
 448     gint i;
 449
 450     DBusMessage *reply;
 451
 452     _DROUTE_DEBUG ("DRoute (handle introspection): %s\n", pathstr);
 453
 454     if (g_strcmp0 (member, "Introspect"))
 455         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 456
 457     output = g_string_new(introspection_header);
 458
 459     g_string_append_printf(output, introspection_node_element, pathstr);
 460
 461     if (!path->get_datum || path_get_datum (path, pathstr))
 462       {
 463         for (i=0; i < path->introspection->len; i++)
 464           {
 465             gchar *introspect = (gchar *) g_ptr_array_index (path->introspection, i);
 466             g_string_append (output, introspect);
 467           }
 468       }
 469
 470     if (path->introspect_children_cb)
 471       {
 472         gchar *children = (*path->introspect_children_cb) (pathstr, path->introspect_children_data);
 473         if (children)
 474           {
 475             g_string_append (output, children);
 476             g_free (children);
 477           }
 478       }
 479
 480     g_string_append(output, introspection_footer);
 481     final = g_string_free(output, FALSE);
 482
 483     reply = dbus_message_new_method_return (message);
 484     if (!reply)
 485         oom ();
 486     dbus_message_append_args(reply, DBUS_TYPE_STRING, &final,
 487                              DBUS_TYPE_INVALID);
 488     dbus_connection_send (bus, reply, NULL);
 489
 490     dbus_message_unref (reply);
 491     g_free(final);
 492     return DBUS_HANDLER_RESULT_HANDLED;
 493 }
 494
 495 /*---------------------------------------------------------------------------*/
 496
 497 static DBusHandlerResult
 498 handle_other (DBusConnection *bus,
 499               DBusMessage    *message,
 500               DRoutePath     *path,
 501               const gchar    *iface,
 502               const gchar    *member,
 503               const gchar    *pathstr)
 504 {
 505     gint result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 506
 507     StrPair pair;
 508     DRouteFunction func;
 509     DBusMessage *reply = NULL;
 510
 511     void *datum;
 512
 513     pair.one = iface;
 514     pair.two = member;
 515
 516     _DROUTE_DEBUG ("DRoute (handle other): %s|%s on %s\n", member, iface, pathstr);
 517
 518     func = (DRouteFunction) g_hash_table_lookup (path->methods, &pair);
 519     if (func != NULL)
 520       {
 521         datum = path_get_datum (path, pathstr);
 522         if (!datum)
 523             reply = droute_object_does_not_exist_error (message);
 524         else
 525             reply = (func) (bus, message, datum);
 526
 527         if (!reply)
 528           {
 529             /* All D-Bus method calls must have a reply.
 530              * If one is not provided presume that the call has a void
 531              * return and no error has occured.
 532              */
 533             reply = dbus_message_new_method_return (message);
 534           }
 535         dbus_connection_send (bus, reply, NULL);
 536         dbus_message_unref (reply);
 537         result = DBUS_HANDLER_RESULT_HANDLED;
 538       }
 539
 540     _DROUTE_DEBUG ("DRoute (handle other) (reply): type %d\n",
 541                    dbus_message_get_type(reply));
 542     return result;
 543 }
 544
 545 /*---------------------------------------------------------------------------*/
 546
 547 static DBusHandlerResult
 548 handle_message (DBusConnection *bus, DBusMessage *message, void *user_data)
 549 {
 550     DRoutePath *path = (DRoutePath *) user_data;
 551     const gchar *iface   = dbus_message_get_interface (message);
 552     const gchar *member  = dbus_message_get_member (message);
 553     const gint   type    = dbus_message_get_type (message);
 554     const gchar *pathstr = dbus_message_get_path (message);
 555
 556     DBusHandlerResult result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 557
 558     _DROUTE_DEBUG ("DRoute (handle message): %s|%s of type %d on %s\n", member, iface, type, pathstr);
 559
 560     /* Check for basic reasons not to handle */
 561     if (type   != DBUS_MESSAGE_TYPE_METHOD_CALL ||
 562         member == NULL ||
 563         iface  == NULL)
 564         return result;
 565
 566     if (!strcmp (pathstr, DBUS_PATH_DBUS))
 567         result = handle_dbus (bus, message, iface, member, pathstr);
 568     else if (!strcmp (iface, "org.freedesktop.DBus.Properties"))
 569         result = handle_properties (bus, message, path, iface, member, pathstr);
 570     else if (!strcmp (iface, "org.freedesktop.DBus.Introspectable"))
 571         result = handle_introspection (bus, message, path, iface, member, pathstr);
 572     else
 573         result = handle_other (bus, message, path, iface, member, pathstr);
 574 #if 0
 575     if (result == DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
 576         g_print ("DRoute | Unhandled message: %s|%s of type %d on %s\n", member, iface, type, pathstr);
 577 #endif
 578
 579     return result;
 580 }
 581
 582 /*---------------------------------------------------------------------------*/
 583
 584 static DBusMessage *
 585 droute_object_does_not_exist_error (DBusMessage *message)
 586 {
 587     DBusMessage *reply;
 588     gchar       *errmsg;
 589
 590     errmsg= g_strdup_printf (
 591             "Method \"%s\" with signature \"%s\" on interface \"%s\" could not be processed as object %s does not exist\n",
 592             dbus_message_get_member (message),
 593             dbus_message_get_signature (message),
 594             dbus_message_get_interface (message),
 595             dbus_message_get_path (message));
 596     reply = dbus_message_new_error (message,
 597                                     DBUS_ERROR_FAILED,
 598                                     errmsg);
 599     g_free (errmsg);
 600     return reply;
 601 }
 602
 603 /*---------------------------------------------------------------------------*/
 604
 605 DBusMessage *
 606 droute_not_yet_handled_error (DBusMessage *message)
 607 {
 608     DBusMessage *reply;
 609     gchar       *errmsg;
 610
 611     errmsg= g_strdup_printf (
 612             "Method \"%s\" with signature \"%s\" on interface \"%s\" doesn't exist\n",
 613             dbus_message_get_member (message),
 614             dbus_message_get_signature (message),
 615             dbus_message_get_interface (message));
 616     reply = dbus_message_new_error (message,
 617                                     DBUS_ERROR_UNKNOWN_METHOD,
 618                                     errmsg);
 619     g_free (errmsg);
 620     return reply;
 621 }
 622
 623 DBusMessage *
 624 droute_out_of_memory_error (DBusMessage *message)
 625 {
 626     DBusMessage *reply;
 627     gchar       *errmsg;
 628
 629     errmsg= g_strdup_printf (
 630             "Method \"%s\" with signature \"%s\" on interface \"%s\" could not be processed due to lack of memory\n",
 631             dbus_message_get_member (message),
 632             dbus_message_get_signature (message),
 633             dbus_message_get_interface (message));
 634     reply = dbus_message_new_error (message,
 635                                     DBUS_ERROR_NO_MEMORY,
 636                                     errmsg);
 637     g_free (errmsg);
 638     return reply;
 639 }
 640
 641 DBusMessage *
 642 droute_invalid_arguments_error (DBusMessage *message)
 643 {
 644     DBusMessage *reply;
 645     gchar       *errmsg;
 646
 647     errmsg= g_strdup_printf (
 648             "Method \"%s\" with signature \"%s\" on interface \"%s\" was supplied with invalid arguments\n",
 649             dbus_message_get_member (message),
 650             dbus_message_get_signature (message),
 651             dbus_message_get_interface (message));
 652     reply = dbus_message_new_error (message,
 653                                     DBUS_ERROR_INVALID_ARGS,
 654                                     errmsg);
 655     g_free (errmsg);
 656     return reply;
 657 }
 658
 659 void
 660 droute_path_register (DRoutePath *path, DBusConnection *bus)
 661 {
 662     if (path->prefix)
 663       dbus_connection_register_fallback (bus, path->path, &droute_vtable, path);
 664     else
 665       dbus_connection_register_object_path (bus, path->path,
 666                                             &droute_vtable, path);
 667 }
 668
 669 void
 670 droute_context_register (DRouteContext *cnx, DBusConnection *bus)
 671 {
 672     g_ptr_array_foreach (cnx->registered_paths, (GFunc) droute_path_register,
 673                          bus);
 674 }
 675
 676 void
 677 droute_intercept_dbus (DBusConnection *bus)
 678 {
 679     dbus_connection_register_object_path (bus, DBUS_PATH_DBUS,
 680                                           &droute_vtable, NULL);
 681 }
 682 /*END------------------------------------------------------------------------*/