dbus/helpers.c

   1 /* -*- Mode: C ; c-basic-offset: 2 -*- */
   2 /*
   3  * LADI Session Handler (ladish)
   4  *
   5  * Copyright (C) 2008, 2009 Nedko Arnaudov <nedko@arnaudov.name>
   6  * Copyright (C) 2008 Juuso Alasuutari <juuso.alasuutari@gmail.com>
   7  *
   8  **************************************************************************
   9  * This file contains code of the D-Bus helpers
  10  **************************************************************************
  11  *
  12  * LADI Session Handler is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * LADI Session Handler is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with LADI Session Handler. If not, see <http://www.gnu.org/licenses/>
  24  * or write to the Free Software Foundation, Inc.,
  25  * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  26  */
  27
  28 #include <stdbool.h>
  29 #include <dbus/dbus.h>
  30 #include <string.h>
  31 #include <assert.h>
  32
  33 #include "helpers.h"
  34 #include "method.h"
  35 #include "../common/debug.h"
  36
  37 DBusConnection * g_dbus_connection;
  38 DBusError g_dbus_error;
  39
  40 bool dbus_maybe_add_dict_entry_string(DBusMessageIter *dict_iter_ptr, const char * key, const char * value)
  41 {
  42   DBusMessageIter dict_entry_iter;
  43
  44   if (value == NULL)
  45   {
  46     return true;
  47   }
  48
  49   if (!dbus_message_iter_open_container(dict_iter_ptr, DBUS_TYPE_DICT_ENTRY, NULL, &dict_entry_iter))
  50   {
  51     return false;
  52   }
  53
  54   if (!dbus_message_iter_append_basic(&dict_entry_iter, DBUS_TYPE_STRING, (const void *) &key))
  55   {
  56     dbus_message_iter_close_container(dict_iter_ptr, &dict_entry_iter);
  57     return false;
  58   }
  59
  60   method_iter_append_variant(&dict_entry_iter, DBUS_TYPE_STRING, &value);
  61
  62   if (!dbus_message_iter_close_container(dict_iter_ptr, &dict_entry_iter))
  63   {
  64     return false;
  65   }
  66
  67   return true;
  68 }
  69
  70 bool dbus_add_dict_entry_uint32(DBusMessageIter * dict_iter_ptr, const char * key, dbus_uint32_t value)
  71 {
  72   DBusMessageIter dict_entry_iter;
  73
  74   if (!dbus_message_iter_open_container(dict_iter_ptr, DBUS_TYPE_DICT_ENTRY, NULL, &dict_entry_iter))
  75   {
  76     return false;
  77   }
  78
  79   if (!dbus_message_iter_append_basic(&dict_entry_iter, DBUS_TYPE_STRING, (const void *) &key))
  80   {
  81     dbus_message_iter_close_container(dict_iter_ptr, &dict_entry_iter);
  82     return false;
  83   }
  84
  85   method_iter_append_variant(&dict_entry_iter, DBUS_TYPE_UINT32, &value);
  86
  87   if (!dbus_message_iter_close_container(dict_iter_ptr, &dict_entry_iter))
  88   {
  89     return false;
  90   }
  91
  92   return true;
  93 }
  94
  95 bool dbus_add_dict_entry_bool(DBusMessageIter * dict_iter_ptr, const char * key, dbus_bool_t value)
  96 {
  97   DBusMessageIter dict_entry_iter;
  98
  99   if (!dbus_message_iter_open_container(dict_iter_ptr, DBUS_TYPE_DICT_ENTRY, NULL, &dict_entry_iter))
 100   {
 101     return false;
 102   }
 103
 104   if (!dbus_message_iter_append_basic(&dict_entry_iter, DBUS_TYPE_STRING, (const void *) &key))
 105   {
 106     dbus_message_iter_close_container(dict_iter_ptr, &dict_entry_iter);
 107     return false;
 108   }
 109
 110   method_iter_append_variant(&dict_entry_iter, DBUS_TYPE_BOOLEAN, &value);
 111
 112   if (!dbus_message_iter_close_container(dict_iter_ptr, &dict_entry_iter))
 113   {
 114     return false;
 115   }
 116
 117   return true;
 118 }
 119
 120 bool
 121 dbus_call_simple(
 122   const char * service,
 123   const char * object,
 124   const char * iface,
 125   const char * method,
 126   char * input_signature,
 127   ...)
 128 {
 129   DBusMessageIter iter;
 130   DBusMessage * request_ptr;
 131   DBusMessage * reply_ptr;
 132   const char * output_signature;
 133   const char * reply_signature;
 134   va_list ap;
 135   bool ret;
 136   void * parameter_ptr;
 137   int type;
 138   DBusSignatureIter sig_iter;
 139
 140   //lash_info("dbus_call_simple('%s', '%s', '%s', '%s')", service, object, iface, method);
 141
 142   ret = false;
 143   va_start(ap, input_signature);
 144
 145   if (!dbus_signature_validate(input_signature, NULL))
 146   {
 147     lash_error("input signature '%s' is invalid", input_signature);
 148     goto fail;
 149   }
 150
 151   dbus_signature_iter_init(&sig_iter, input_signature);
 152
 153   request_ptr = dbus_message_new_method_call(service, object, iface, method);
 154   if (request_ptr == NULL)
 155   {
 156     lash_error("dbus_message_new_method_call() failed.");
 157     goto fail;
 158   }
 159
 160   dbus_message_iter_init_append(request_ptr, &iter);
 161
 162   while (*input_signature != '\0')
 163   {
 164     type = dbus_signature_iter_get_current_type(&sig_iter);
 165     if (!dbus_type_is_basic(type))
 166     {
 167       lash_error("non-basic input parameter '%c' (%d)", *input_signature, type);
 168       goto fail;
 169     }
 170
 171     parameter_ptr = va_arg(ap, void *);
 172
 173     if (!dbus_message_iter_append_basic(&iter, type, parameter_ptr))
 174     {
 175       lash_error("dbus_message_iter_append_basic() failed.");
 176       goto fail;
 177     }
 178
 179     dbus_signature_iter_next(&sig_iter);
 180     input_signature++;
 181   }
 182
 183   output_signature = va_arg(ap, const char *);
 184
 185   reply_ptr = dbus_connection_send_with_reply_and_block(
 186     g_dbus_connection,
 187     request_ptr,
 188     DBUS_CALL_DEFAULT_TIMEOUT,
 189     &g_dbus_error);
 190
 191   dbus_message_unref(request_ptr);
 192
 193   if (reply_ptr == NULL)
 194   {
 195     lash_error("calling method '%s' failed, error is '%s'", method, g_dbus_error.message);
 196     dbus_error_free(&g_dbus_error);
 197     goto fail;
 198   }
 199
 200   if (output_signature != NULL)
 201   {
 202     reply_signature = dbus_message_get_signature(reply_ptr);
 203
 204     if (strcmp(reply_signature, output_signature) != 0)
 205     {
 206       lash_error("reply signature is '%s' but expected signature is '%s'", reply_signature, output_signature);
 207     }
 208
 209     dbus_message_iter_init(reply_ptr, &iter);
 210
 211     while (*output_signature++ != '\0')
 212     {
 213       assert(dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_INVALID); /* we've checked the signature, this should not happen */
 214       parameter_ptr = va_arg(ap, void *);
 215       dbus_message_iter_get_basic(&iter, parameter_ptr);
 216       dbus_message_iter_next(&iter);
 217     }
 218
 219     assert(dbus_message_iter_get_arg_type(&iter) == DBUS_TYPE_INVALID); /* we've checked the signature, this should not happen */
 220   }
 221   else
 222   {
 223     parameter_ptr = va_arg(ap, DBusMessage **);
 224     *(DBusMessage **)parameter_ptr = reply_ptr;
 225   }
 226
 227   ret = true;
 228
 229 fail:
 230   va_end(ap);
 231   return ret;
 232 }
 233
 234 static
 235 const char *
 236 compose_signal_match(
 237   const char * service,
 238   const char * object,
 239   const char * iface,
 240   const char * signal)
 241 {
 242   static char rule[1024];
 243   snprintf(rule, sizeof(rule), "type='signal',sender='%s',path='%s',interface='%s',member='%s'", service, object, iface, signal);
 244   return rule;
 245 }
 246
 247 bool
 248 dbus_register_object_signal_handler(
 249   DBusConnection * connection,
 250   const char * service,
 251   const char * object,
 252   const char * iface,
 253   const char * const * signals,
 254   DBusHandleMessageFunction handler,
 255   void * handler_data)
 256 {
 257   const char * const * signal;
 258
 259   for (signal = signals; *signal != NULL; signal++)
 260   {
 261     dbus_bus_add_match(connection, compose_signal_match(service, object, iface, *signal), &g_dbus_error);
 262     if (dbus_error_is_set(&g_dbus_error))
 263     {
 264       lash_error("Failed to add D-Bus match rule: %s", g_dbus_error.message);
 265       dbus_error_free(&g_dbus_error);
 266       return false;
 267     }
 268   }
 269
 270   dbus_connection_add_filter(g_dbus_connection, handler, handler_data, NULL);
 271
 272   return true;
 273 }
 274
 275 bool
 276 dbus_unregister_object_signal_handler(
 277   DBusConnection * connection,
 278   const char * service,
 279   const char * object,
 280   const char * iface,
 281   const char * const * signals,
 282   DBusHandleMessageFunction handler,
 283   void * handler_data)
 284 {
 285   const char * const * signal;
 286
 287   for (signal = signals; *signal != NULL; signal++)
 288   {
 289     dbus_bus_remove_match(connection, compose_signal_match(service, object, iface, *signal), &g_dbus_error);
 290     if (dbus_error_is_set(&g_dbus_error))
 291     {
 292       lash_error("Failed to add D-Bus match rule: %s", g_dbus_error.message);
 293       dbus_error_free(&g_dbus_error);
 294       return false;
 295     }
 296   }
 297
 298   dbus_connection_remove_filter(g_dbus_connection, handler, handler_data);
 299
 300   return true;
 301 }