bus/driver.c

   1 /* -*- mode: C; c-file-style: "gnu" -*- */
   2 /* driver.c  Bus client (driver)
   3  *
   4  * Copyright (C) 2003  CodeFactory AB
   5  *
   6  * Licensed under the Academic Free License version 1.2
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program 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
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  *
  22  */
  23
  24 #include "connection.h"
  25 #include "driver.h"
  26 #include "dispatch.h"
  27 #include "services.h"
  28 #include <dbus/dbus-string.h>
  29 #include <dbus/dbus-internals.h>
  30 #include <string.h>
  31
  32 static void bus_driver_send_welcome_message (DBusConnection *connection,
  33                                              DBusMessage    *hello_message);
  34
  35 void
  36 bus_driver_send_service_deleted (const char *service_name)
  37 {
  38   DBusMessage *message;
  39
  40   _dbus_verbose ("sending service deleted: %s\n", service_name);
  41
  42   _DBUS_HANDLE_OOM (message = dbus_message_new (DBUS_SERVICE_BROADCAST,
  43                                                 DBUS_MESSAGE_SERVICE_DELETED));
  44
  45   _DBUS_HANDLE_OOM (dbus_message_set_sender (message, DBUS_SERVICE_DBUS));
  46
  47   _DBUS_HANDLE_OOM (dbus_message_append_fields (message,
  48                                                 DBUS_TYPE_STRING, service_name,
  49                                                 0));
  50   bus_dispatch_broadcast_message (message);
  51   dbus_message_unref (message);
  52 }
  53
  54 static void
  55 bus_driver_send_service_created (const char *service_name)
  56 {
  57   DBusMessage *message;
  58
  59   _DBUS_HANDLE_OOM (message = dbus_message_new (DBUS_SERVICE_BROADCAST,
  60                                                 DBUS_MESSAGE_SERVICE_CREATED));
  61
  62   _DBUS_HANDLE_OOM (dbus_message_set_sender (message, DBUS_SERVICE_DBUS));
  63
  64   _DBUS_HANDLE_OOM (dbus_message_append_fields (message,
  65                                                 DBUS_TYPE_STRING, service_name,
  66                                                 0));
  67   bus_dispatch_broadcast_message (message);
  68   dbus_message_unref (message);
  69 }
  70
  71 void
  72 bus_driver_send_service_lost (DBusConnection *connection,
  73                               const char *service_name)
  74 {
  75   DBusMessage *message;
  76
  77   _DBUS_HANDLE_OOM (message = dbus_message_new (DBUS_SERVICE_BROADCAST,
  78                                                 DBUS_MESSAGE_SERVICE_LOST));
  79
  80   _DBUS_HANDLE_OOM (dbus_message_set_sender (message, DBUS_SERVICE_DBUS));
  81   _DBUS_HANDLE_OOM (dbus_message_append_fields (message,
  82                                                 DBUS_TYPE_STRING, service_name,
  83                                                 0));
  84   _DBUS_HANDLE_OOM (dbus_connection_send_message (connection, message, NULL, NULL));
  85
  86   dbus_message_unref (message);
  87 }
  88
  89 void
  90 bus_driver_send_service_acquired (DBusConnection *connection,
  91                                   const char *service_name)
  92 {
  93   DBusMessage *message;
  94
  95   _DBUS_HANDLE_OOM (message = dbus_message_new (DBUS_SERVICE_BROADCAST,
  96                                                 DBUS_MESSAGE_SERVICE_ACQUIRED));
  97
  98   _DBUS_HANDLE_OOM (dbus_message_set_sender (message, DBUS_SERVICE_DBUS));
  99   _DBUS_HANDLE_OOM (dbus_message_append_fields (message,
 100                                                 DBUS_TYPE_STRING, service_name,
 101                                                 0));
 102   _DBUS_HANDLE_OOM (dbus_connection_send_message (connection, message, NULL, NULL));
 103
 104   dbus_message_unref (message);
 105 }
 106
 107 static dbus_bool_t
 108 create_unique_client_name (DBusString *str)
 109 {
 110   /* We never want to use the same unique client name twice, because
 111    * we want to guarantee that if you send a message to a given unique
 112    * name, you always get the same application. So we use two numbers
 113    * for INT_MAX * INT_MAX combinations, should be pretty safe against
 114    * wraparound.
 115    */
 116   static int next_major_number = 0;
 117   static int next_minor_number = 0;
 118   int len;
 119
 120   len = _dbus_string_get_length (str);
 121
 122   while (TRUE)
 123     {
 124       /* start out with 1-0, go to 1-1, 1-2, 1-3,
 125        * up to 1-MAXINT, then 2-0, 2-1, etc.
 126        */
 127       if (next_minor_number <= 0)
 128         {
 129           next_major_number += 1;
 130           next_minor_number = 0;
 131           if (next_major_number <= 0)
 132             _dbus_assert_not_reached ("INT_MAX * INT_MAX clients were added");
 133         }
 134
 135       _dbus_assert (next_major_number > 0);
 136       _dbus_assert (next_minor_number >= 0);
 137
 138       /* appname:MAJOR-MINOR */
 139
 140       if (!_dbus_string_append (str, ":"))
 141         return FALSE;
 142
 143       if (!_dbus_string_append_int (str, next_major_number))
 144         return FALSE;
 145
 146       if (!_dbus_string_append (str, "-"))
 147         return FALSE;
 148
 149       if (!_dbus_string_append_int (str, next_minor_number))
 150         return FALSE;
 151
 152       next_minor_number += 1;
 153
 154       /* Check if a client with the name exists */
 155       if (bus_service_lookup (str, FALSE) == NULL)
 156         break;
 157
 158       /* drop the number again, try the next one. */
 159       _dbus_string_set_length (str, len);
 160     }
 161
 162   return TRUE;
 163 }
 164
 165 static void
 166 bus_driver_handle_hello (DBusConnection *connection,
 167                          DBusMessage    *message)
 168 {
 169   DBusString unique_name;
 170   BusService *service;
 171
 172   _DBUS_HANDLE_OOM (_dbus_string_init (&unique_name, _DBUS_INT_MAX));
 173   _DBUS_HANDLE_OOM (create_unique_client_name (&unique_name));
 174
 175   /* Create the service */
 176   _DBUS_HANDLE_OOM (service = bus_service_lookup (&unique_name, TRUE));
 177   bus_service_set_prohibit_replacement (service, TRUE);
 178
 179   /* Add the connection as the owner */
 180   _DBUS_HANDLE_OOM (bus_service_add_owner (service, connection));
 181   _DBUS_HANDLE_OOM (bus_connection_set_name (connection, &unique_name));
 182
 183   _DBUS_HANDLE_OOM (dbus_message_set_sender (message,
 184                                              bus_connection_get_name (connection)));
 185
 186   _dbus_string_free (&unique_name);
 187
 188   _DBUS_HANDLE_OOM (bus_driver_send_welcome_message (connection, message));
 189
 190   /* Broadcast a service created message */
 191   bus_driver_send_service_created (bus_service_get_name (service));
 192 }
 193
 194 static void
 195 bus_driver_send_welcome_message (DBusConnection *connection,
 196                                  DBusMessage    *hello_message)
 197 {
 198   DBusMessage *welcome;
 199   const char *name;
 200
 201   name = bus_connection_get_name (connection);
 202   _dbus_assert (name != NULL);
 203
 204   _DBUS_HANDLE_OOM (welcome = dbus_message_new_reply (hello_message));
 205
 206   _DBUS_HANDLE_OOM (dbus_message_set_sender (welcome, DBUS_SERVICE_DBUS));
 207
 208   _DBUS_HANDLE_OOM (dbus_message_append_fields (welcome,
 209                                                 DBUS_TYPE_STRING, name,
 210                                                 NULL));
 211
 212   _DBUS_HANDLE_OOM (dbus_connection_send_message (connection, welcome, NULL, NULL));
 213
 214   dbus_message_unref (welcome);
 215 }
 216
 217 static void
 218 bus_driver_handle_list_services (DBusConnection *connection,
 219                                  DBusMessage    *message)
 220 {
 221   DBusMessage *reply;
 222   int len, i;
 223   char **services;
 224
 225   _DBUS_HANDLE_OOM (reply = dbus_message_new_reply (message));
 226
 227   _DBUS_HANDLE_OOM (services = bus_services_list (&len));
 228
 229   _DBUS_HANDLE_OOM (dbus_message_append_fields (reply,
 230                                                 DBUS_TYPE_STRING_ARRAY, services, len,
 231                                                 0));
 232
 233   _DBUS_HANDLE_OOM (dbus_connection_send_message (connection, reply, NULL, NULL));
 234
 235   dbus_message_unref (reply);
 236
 237   if (services != NULL)
 238     {
 239       for (i = 0; i < len; i++)
 240         dbus_free (services[i]);
 241       dbus_free (services);
 242     }
 243 }
 244
 245 static void
 246 bus_driver_handle_acquire_service (DBusConnection *connection,
 247                                    DBusMessage    *message)
 248 {
 249   DBusMessage *reply;
 250   DBusResultCode result;
 251   DBusString service_name;
 252   BusService *service;
 253   char *name;
 254   int service_reply;
 255   int flags;
 256
 257   _DBUS_HANDLE_OOM ((result = dbus_message_get_fields (message,
 258                                                        DBUS_TYPE_STRING, &name,
 259                                                        DBUS_TYPE_UINT32, &flags,
 260                                                        0)) != DBUS_RESULT_NO_MEMORY);
 261
 262   if (result != DBUS_RESULT_SUCCESS)
 263     {
 264       dbus_free (name);
 265       dbus_connection_disconnect (connection);
 266       return;
 267     }
 268
 269   _dbus_verbose ("Trying to own service %s with flags %d\n", name, flags);
 270
 271   _dbus_string_init_const (&service_name, name);
 272   service = bus_service_lookup (&service_name, TRUE);
 273
 274   _DBUS_HANDLE_OOM ((reply = dbus_message_new_reply (message)));
 275
 276   /*
 277    * Check if the service already has an owner
 278    */
 279   if (bus_service_get_primary_owner (service) != NULL)
 280     {
 281       if (bus_service_has_owner (service, connection))
 282         service_reply = DBUS_SERVICE_REPLY_ALREADY_OWNER;
 283       else if (!(flags & DBUS_SERVICE_FLAG_REPLACE_EXISTING))
 284         service_reply = DBUS_SERVICE_REPLY_SERVICE_EXISTS;
 285       else
 286         {
 287           if (bus_service_get_prohibit_replacement (service))
 288             {
 289
 290               /* Queue the connection */
 291               _DBUS_HANDLE_OOM (bus_service_add_owner (service, connection));
 292
 293               service_reply = DBUS_SERVICE_REPLY_IN_QUEUE;
 294             }
 295           else
 296             {
 297               DBusConnection *owner;
 298
 299               /* We can replace the primary owner */
 300               owner = bus_service_get_primary_owner (service);
 301
 302               /* We enqueue the new owner and remove the first one because
 303                * that will cause ServiceAcquired and ServiceLost messages to
 304                * be sent.
 305                */
 306               _DBUS_HANDLE_OOM (bus_service_add_owner (service, connection));
 307               bus_service_remove_owner (service, owner);
 308               _dbus_assert (connection == bus_service_get_primary_owner (service));
 309               service_reply = DBUS_SERVICE_REPLY_PRIMARY_OWNER;
 310             }
 311         }
 312     }
 313   else
 314     {
 315       bus_service_set_prohibit_replacement (service,
 316                                             (flags & DBUS_SERVICE_FLAG_PROHIBIT_REPLACEMENT));
 317
 318       /* Broadcast service created message */
 319       bus_driver_send_service_created (bus_service_get_name (service));
 320
 321       _DBUS_HANDLE_OOM (bus_service_add_owner (service, connection));
 322
 323       service_reply = DBUS_SERVICE_REPLY_PRIMARY_OWNER;
 324     }
 325
 326   _DBUS_HANDLE_OOM (dbus_message_append_fields (reply, DBUS_TYPE_UINT32, service_reply, 0));
 327
 328   /* Send service reply */
 329   _DBUS_HANDLE_OOM (dbus_connection_send_message (connection, reply, NULL, NULL));
 330   dbus_free (name);
 331   dbus_message_unref (reply);
 332 }
 333
 334 static void
 335 bus_driver_handle_service_exists (DBusConnection *connection,
 336                                   DBusMessage    *message)
 337 {
 338   DBusMessage *reply;
 339   DBusResultCode result;
 340   DBusString service_name;
 341   BusService *service;
 342   char *name;
 343
 344   _DBUS_HANDLE_OOM ((result = dbus_message_get_fields (message,
 345                                                        DBUS_TYPE_STRING, &name,
 346                                                        0)) != DBUS_RESULT_NO_MEMORY);
 347  if (result != DBUS_RESULT_SUCCESS)
 348     {
 349       dbus_free (name);
 350       dbus_connection_disconnect (connection);
 351       return;
 352     }
 353
 354  _dbus_string_init_const (&service_name, name);
 355  service = bus_service_lookup (&service_name, FALSE);
 356
 357  _DBUS_HANDLE_OOM ((reply = dbus_message_new_reply (message)));
 358  _DBUS_HANDLE_OOM (dbus_message_set_sender (reply, DBUS_SERVICE_DBUS));
 359
 360  _DBUS_HANDLE_OOM (dbus_message_append_fields (reply,
 361                                                DBUS_TYPE_UINT32, service != NULL,
 362                                                0));
 363  _DBUS_HANDLE_OOM (dbus_connection_send_message (connection, reply, NULL, NULL));
 364  dbus_message_unref (reply);
 365  dbus_free (name);
 366 }
 367
 368 void
 369 bus_driver_handle_message (DBusConnection *connection,
 370                            DBusMessage    *message)
 371 {
 372   const char *name, *sender;
 373
 374   _dbus_verbose ("Driver got a message: %s\n",
 375                  dbus_message_get_name (message));
 376
 377   name = dbus_message_get_name (message);
 378   sender = dbus_message_get_sender (message);
 379
 380   if (sender == NULL && (strcmp (name, DBUS_MESSAGE_HELLO) != 0))
 381     {
 382       _dbus_verbose ("Trying to send a message without being registered. Disconnecting.\n");
 383       dbus_connection_disconnect (connection);
 384       return;
 385     }
 386
 387   /* Now check names. */
 388   if (strcmp (name, DBUS_MESSAGE_HELLO) == 0)
 389     bus_driver_handle_hello (connection, message);
 390   else if (strcmp (name, DBUS_MESSAGE_LIST_SERVICES) == 0)
 391     bus_driver_handle_list_services (connection, message);
 392   else if (strcmp (name, DBUS_MESSAGE_ACQUIRE_SERVICE) == 0)
 393     bus_driver_handle_acquire_service (connection, message);
 394   else if (strcmp (name, DBUS_MESSAGE_SERVICE_EXISTS) == 0)
 395     bus_driver_handle_service_exists (connection, message);
 396
 397 }
 398
 399 void
 400 bus_driver_remove_connection (DBusConnection *connection)
 401 {
 402   /* Does nothing for now */
 403 }