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
  27 #include "droute.h"
  28 #include "droute-pairhash.h"
  29
  30 #define CHUNKS_DEFAULT (512)
  31
  32 #define oom() g_error ("D-Bus out of memory, this message will fail anyway")
  33
  34 struct _DRouteContext
  35 {
  36     DBusConnection       *bus;
  37     GPtrArray            *registered_paths;
  38
  39     gchar                *introspect_dir;
  40 };
  41
  42 struct _DRoutePath
  43 {
  44     DRouteContext        *cnx;
  45     GStringChunk         *chunks;
  46     GPtrArray            *interfaces;
  47     GHashTable           *methods;
  48     GHashTable           *properties;
  49
  50     void                   *user_data;
  51     DRouteGetDatumFunction  get_datum;
  52 };
  53
  54 /*---------------------------------------------------------------------------*/
  55
  56 typedef struct PropertyPair
  57 {
  58     DRoutePropertyFunction get;
  59     DRoutePropertyFunction set;
  60 } PropertyPair;
  61
  62 /*---------------------------------------------------------------------------*/
  63
  64 static DBusHandlerResult
  65 handle_message (DBusConnection *bus, DBusMessage *message, void *user_data);
  66
  67 /*---------------------------------------------------------------------------*/
  68
  69 static DRoutePath *
  70 path_new (DRouteContext *cnx,
  71           void    *user_data,
  72           DRouteGetDatumFunction get_datum)
  73 {
  74     DRoutePath *new_path;
  75
  76     new_path = g_new0 (DRoutePath, 0);
  77     new_path->cnx = cnx;
  78     new_path->chunks = g_string_chunk_new (CHUNKS_DEFAULT);
  79     new_path->interfaces = g_ptr_array_new ();
  80
  81     new_path->methods = g_hash_table_new_full ((GHashFunc)str_pair_hash,
  82                                                str_pair_equal,
  83                                                g_free,
  84                                                NULL);
  85
  86     new_path->properties = g_hash_table_new_full ((GHashFunc)str_pair_hash,
  87                                                   str_pair_equal,
  88                                                   g_free,
  89                                                   NULL);
  90
  91     new_path->user_data = user_data;
  92     new_path->get_datum = get_datum;
  93
  94     return new_path;
  95 }
  96
  97 static void
  98 path_free (DRoutePath *path, gpointer user_data)
  99 {
 100     g_string_chunk_free  (path->chunks);
 101     g_ptr_array_free     (path->interfaces, TRUE);
 102     g_hash_table_destroy (path->methods);
 103     g_hash_table_destroy (path->properties);
 104 }
 105
 106 static void *
 107 path_get_datum (DRoutePath *path, const gchar *pathstr)
 108 {
 109     if (path->get_datum != NULL)
 110         return (path->get_datum) (pathstr, path->user_data);
 111     else
 112         return path->user_data;
 113 }
 114
 115 /*---------------------------------------------------------------------------*/
 116
 117 DRouteContext *
 118 droute_new (DBusConnection *bus, const char *introspect_dir)
 119 {
 120     DRouteContext *cnx;
 121
 122     cnx = g_new0 (DRouteContext, 1);
 123     cnx->bus = bus;
 124     cnx->registered_paths = g_ptr_array_new ();
 125     cnx->introspect_dir = g_strdup(introspect_dir);
 126 }
 127
 128 void
 129 droute_free (DRouteContext *cnx)
 130 {
 131     g_pointer_array_foreach ((GFunc) path_free, cnx->registered_paths, NULL);
 132     g_free (cnx->introspect_dir);
 133     g_free (cnx);
 134 }
 135
 136 /*---------------------------------------------------------------------------*/
 137
 138 static DBusObjectPathVTable droute_vtable =
 139 {
 140   NULL,
 141   &handle_message,
 142   NULL, NULL, NULL, NULL
 143 };
 144
 145 DRoutePath *
 146 droute_add_one (DRouteContext *cnx,
 147                 const char    *path,
 148                 const void    *data)
 149 {
 150     DRoutePath *new_path;
 151
 152     new_path = path_new (cnx, (void *) data, NULL);
 153
 154     if (!dbus_connection_register_object_path (cnx->bus, path, &droute_vtable, new_path))
 155         oom();
 156
 157     g_ptr_array_add (cnx->registered_paths, new_path);
 158     return new_path;
 159 }
 160
 161 DRoutePath *
 162 droute_add_many (DRouteContext *cnx,
 163                  const char    *path,
 164                  const void    *data,
 165                  const DRouteGetDatumFunction get_datum)
 166 {
 167     DRoutePath *new_path;
 168
 169     new_path = path_new (cnx, (void *) data, get_datum);
 170
 171     if (!dbus_connection_register_fallback (cnx->bus, path, &droute_vtable, new_path))
 172         oom();
 173
 174     g_ptr_array_add (cnx->registered_paths, new_path);
 175     return new_path;
 176 }
 177
 178 /*---------------------------------------------------------------------------*/
 179
 180 void
 181 droute_path_add_interface(DRoutePath *path,
 182                           const char *name,
 183                           const DRouteMethod   *methods,
 184                           const DRouteProperty *properties)
 185 {
 186     gchar *itf;
 187
 188     g_return_if_fail (name == NULL);
 189
 190     itf = g_string_chunk_insert (path->chunks, name);
 191     g_ptr_array_add (path->interfaces, itf);
 192
 193     for (; methods->name != NULL; methods++)
 194       {
 195         gchar *meth;
 196
 197         meth = g_string_chunk_insert (path->chunks, methods->name);
 198         g_hash_table_insert (path->methods, str_pair_new (itf, meth), methods->func);
 199       }
 200
 201     for (; properties->name != NULL; properties++)
 202       {
 203         gchar *prop;
 204         PropertyPair *pair;
 205
 206         prop = g_string_chunk_insert (path->chunks, properties->name);
 207         pair = g_new (PropertyPair, 1);
 208         pair->get = properties->get;
 209         pair->set = properties->set;
 210         g_hash_table_insert (path->properties, str_pair_new (itf, prop), pair);
 211       }
 212 }
 213
 214 /*---------------------------------------------------------------------------*/
 215
 216 /* The data structures don't support an efficient implementation of GetAll
 217  * and I don't really care.
 218  */
 219 static DBusMessage *
 220 impl_prop_GetAll (DBusMessage *message,
 221                   DRoutePath  *path,
 222                   const char  *pathstr)
 223 {
 224     DBusMessageIter iter, iter_dict, iter_dict_entry;
 225     DBusMessage *reply;
 226     DBusError error;
 227     GHashTableIter prop_iter;
 228
 229     StrPair *key;
 230     PropertyPair *value;
 231     gchar *iface;
 232
 233     void  *datum = path_get_datum (path, pathstr);
 234
 235     dbus_error_init (&error);
 236
 237     if (!dbus_message_get_args
 238                 (message, &error, DBUS_TYPE_STRING, &iface, DBUS_TYPE_INVALID))
 239         return dbus_message_new_error (message, DBUS_ERROR_FAILED, error.message);
 240
 241     reply = dbus_message_new_method_return (message);
 242     if (!reply)
 243         oom ();
 244
 245     dbus_message_iter_init_append (reply, &iter);
 246     if (!dbus_message_iter_open_container
 247                 (&iter, DBUS_TYPE_ARRAY, "{sv}", &iter_dict))
 248         oom ();
 249
 250     g_hash_table_iter_init (&prop_iter, path->properties);
 251     while (g_hash_table_iter_next (&prop_iter, (gpointer*)&key, (gpointer*)&value))
 252       {
 253         if (!g_strcmp (key->one, iface))
 254          {
 255            if (!value->get)
 256               continue;
 257            if (!dbus_message_iter_open_container
 258                         (&iter_dict, DBUS_TYPE_DICT_ENTRY, NULL, &iter_dict_entry))
 259               oom ();
 260            dbus_message_iter_append_basic (&iter_dict_entry, DBUS_TYPE_STRING,
 261                                            key->two);
 262            (value->get) (&iter_dict_entry, datum);
 263            if (!dbus_message_iter_close_container (&iter_dict, &iter_dict_entry))
 264                oom ();
 265          }
 266       }
 267
 268     if (!dbus_message_iter_close_container (&iter, &iter_dict))
 269         oom ();
 270     return reply;
 271 }
 272
 273 static DBusMessage *
 274 impl_prop_GetSet (DBusMessage *message,
 275                   DRoutePath  *path,
 276                   const char  *pathstr,
 277                   gboolean     get)
 278 {
 279     DBusMessage *reply = NULL;
 280     DBusError error;
 281
 282     StrPair pair;
 283     PropertyPair *prop_funcs;
 284
 285     if (!dbus_message_get_args (message,
 286                                 &error,
 287                                 DBUS_TYPE_STRING,
 288                                 &(pair.one),
 289                                 DBUS_TYPE_STRING,
 290                                 &(pair.two),
 291                                 DBUS_TYPE_INVALID))
 292         return dbus_message_new_error (message, DBUS_ERROR_FAILED, error.message);
 293
 294     prop_funcs = (PropertyPair *) g_hash_table_lookup (path->properties, &pair);
 295     if (!prop_funcs)
 296         return dbus_message_new_error (message, DBUS_ERROR_FAILED, "Property unavailable");
 297
 298     if (get && prop_funcs->get)
 299       {
 300         void *datum = path_get_datum (path, pathstr);
 301         DBusMessageIter iter;
 302
 303         reply = dbus_message_new_method_return (message);
 304         dbus_message_iter_init_append (reply, &iter);
 305         (prop_funcs->get) (&iter, datum);
 306       }
 307     else if (!get && prop_funcs->set)
 308       {
 309         void *datum = path_get_datum (path, pathstr);
 310         DBusMessageIter iter;
 311
 312         dbus_message_iter_init_append (message, &iter);
 313         /* Skip the interface and property name */
 314         dbus_message_iter_next(&iter);
 315         dbus_message_iter_next(&iter);
 316         (prop_funcs->get) (&iter, datum);
 317       }
 318     return reply;
 319 }
 320
 321 static DBusHandlerResult
 322 handle_properties (DBusConnection *bus,
 323                    DBusMessage    *message,
 324                    DRoutePath     *path,
 325                    const gchar    *iface,
 326                    const gchar    *member,
 327                    const gchar    *pathstr)
 328 {
 329     DBusMessage *reply;
 330     DBusHandlerResult result = DBUS_HANDLER_RESULT_HANDLED;
 331
 332     if (!g_strcmp0(member, "GetAll"))
 333        reply = impl_prop_GetAll (message, path, pathstr);
 334     else if (!g_strcmp0 (member, "Get"))
 335        reply = impl_prop_GetSet (message, path, pathstr, TRUE);
 336     else if (!g_strcmp0 (member, "Set"))
 337        reply = impl_prop_GetSet (message, path, pathstr, FALSE);
 338     else
 339        result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 340
 341     return result;
 342 }
 343
 344 /*---------------------------------------------------------------------------*/
 345
 346 static const char *introspection_header =
 347 "<?xml version=\"1.0\"?>\n";
 348
 349 static const char *introspection_node_element =
 350 "<node name=\"%s\">\n";
 351
 352 static const char *introspection_footer =
 353 "</node>";
 354
 355 static void
 356 append_interface (GString     *str,
 357                   const gchar *interface,
 358                   const gchar *directory)
 359 {
 360   gchar *filename;
 361   gchar *contents;
 362   gsize len;
 363
 364   GError *err = NULL;
 365
 366   filename = g_build_filename (directory, interface, NULL);
 367
 368   if (g_file_get_contents (filename, &contents, &len, &err))
 369     {
 370       g_string_append_len (str, contents, len);
 371     }
 372   else
 373     {
 374       g_warning ("AT-SPI: Cannot find introspection XML file %s - %s",
 375                  filename, err->message);
 376       g_error_free (err);
 377     }
 378
 379   g_string_append (str, "\n");
 380   g_free (filename);
 381   g_free (contents);
 382 }
 383
 384 static DBusHandlerResult
 385 handle_intropsection (DBusConnection *bus,
 386                       DBusMessage    *message,
 387                       DRoutePath     *path,
 388                       const gchar    *iface,
 389                       const gchar    *member,
 390                       const gchar    *pathstr)
 391 {
 392     GString *output;
 393     gchar *final;
 394     gint i;
 395
 396     DBusMessage *reply;
 397
 398     if (g_strcmp (member, "Introspect"))
 399         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 400
 401     output = g_string_new(introspection_header);
 402
 403     g_string_append_printf(output, introspection_node_element, pathstr);
 404
 405     for (i=0; i < path->interfaces->len; i++)
 406       {
 407         gchar *interface = (gchar *) g_ptr_array_index (path->interfaces, i);
 408         append_interface(output, interface, path->cnx->introspect_dir);
 409       }
 410
 411     g_string_append(output, introspection_footer);
 412     final = g_string_free(output, FALSE);
 413
 414     reply = dbus_message_new_method_return (message);
 415     if (!reply)
 416         oom ();
 417     dbus_message_append_args(reply, DBUS_TYPE_STRING, &final,
 418                              DBUS_TYPE_INVALID);
 419     dbus_connection_send (bus, reply, NULL);
 420
 421     dbus_message_unref (reply);
 422     g_free(final);
 423     return DBUS_HANDLER_RESULT_HANDLED;
 424 }
 425
 426 /*---------------------------------------------------------------------------*/
 427
 428 static DBusHandlerResult
 429 handle_other (DBusConnection *bus,
 430               DBusMessage    *message,
 431               DRoutePath     *path,
 432               const gchar    *iface,
 433               const gchar    *member,
 434               const gchar    *pathstr)
 435 {
 436     gint result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 437
 438     StrPair pair;
 439     DRouteFunction func;
 440     DBusMessage *reply;
 441
 442     pair.one = iface;
 443     pair.two = member;
 444
 445     func = (DRouteFunction) g_hash_table_lookup (path->methods, &pair);
 446     if (func != NULL)
 447       {
 448         void *datum = path_get_datum (path, pathstr);
 449
 450         reply = (func) (bus, message, datum);
 451
 452         if (reply)
 453           {
 454             dbus_connection_send (bus, reply, NULL);
 455             dbus_message_unref (reply);
 456           }
 457         result = DBUS_HANDLER_RESULT_HANDLED;
 458       }
 459     return result;
 460 }
 461
 462 /*---------------------------------------------------------------------------*/
 463
 464 static DBusHandlerResult
 465 handle_message (DBusConnection *bus, DBusMessage *message, void *user_data)
 466 {
 467     DRoutePath *path = (DRoutePath *) user_data;
 468     const gchar *iface   = dbus_message_get_interface (message);
 469     const gchar *member  = dbus_message_get_member (message);
 470     const gint   type    = dbus_message_get_type (message);
 471     const gchar *pathstr = dbus_message_get_path (message);
 472
 473     /* Check for basic reasons not to handle */
 474     if (type   != DBUS_MESSAGE_TYPE_METHOD_CALL ||
 475         member == NULL ||
 476         iface  == NULL)
 477         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 478
 479     if (!strcmp (iface, "org.freedesktop.DBus.Properties"))
 480         return handle_properties (bus, message, path, iface, member, pathstr);
 481
 482     if (!strcmp (iface, "org.freedesktop.DBus.Introspectable"))
 483         return handle_introspection (bus, message, path, iface, member, pathstr);
 484
 485     return handle_other (bus, message, path, iface, member, pathstr);
 486 }
 487
 488 /*END------------------------------------------------------------------------*/