gio/tests/gdbus-example-peer.c

   1 /*
   2
   3 Usage examples (modulo addresses / credentials).
   4
   5 UNIX domain socket transport:
   6
   7  Server:
   8    $ ./gdbus-example-peer --server --address unix:abstract=myaddr
   9    Server is listening at: unix:abstract=myaddr
  10    Client connected.
  11    Peer credentials: GCredentials:unix-user=500,unix-group=500,unix-process=13378
  12    Negotiated capabilities: unix-fd-passing=1
  13    Client said: Hey, it's 1273093080 already!
  14
  15  Client:
  16    $ ./gdbus-example-peer --address unix:abstract=myaddr
  17    Connected.
  18    Negotiated capabilities: unix-fd-passing=1
  19    Server said: You said 'Hey, it's 1273093080 already!'. KTHXBYE!
  20
  21 Nonce-secured TCP transport on the same host:
  22
  23  Server:
  24    $ ./gdbus-example-peer --server --address nonce-tcp:
  25    Server is listening at: nonce-tcp:host=localhost,port=43077,noncefile=/tmp/gdbus-nonce-file-X1ZNCV
  26    Client connected.
  27    Peer credentials: (no credentials received)
  28    Negotiated capabilities: unix-fd-passing=0
  29    Client said: Hey, it's 1273093206 already!
  30
  31  Client:
  32    $ ./gdbus-example-peer -address nonce-tcp:host=localhost,port=43077,noncefile=/tmp/gdbus-nonce-file-X1ZNCV
  33    Connected.
  34    Negotiated capabilities: unix-fd-passing=0
  35    Server said: You said 'Hey, it's 1273093206 already!'. KTHXBYE!
  36
  37 TCP transport on two different hosts with a shared home directory:
  38
  39  Server:
  40    host1 $ ./gdbus-example-peer --server --address tcp:host=0.0.0.0
  41    Server is listening at: tcp:host=0.0.0.0,port=46314
  42    Client connected.
  43    Peer credentials: (no credentials received)
  44    Negotiated capabilities: unix-fd-passing=0
  45    Client said: Hey, it's 1273093337 already!
  46
  47  Client:
  48    host2 $ ./gdbus-example-peer -a tcp:host=host1,port=46314
  49    Connected.
  50    Negotiated capabilities: unix-fd-passing=0
  51    Server said: You said 'Hey, it's 1273093337 already!'. KTHXBYE!
  52
  53 TCP transport on two different hosts without authentication:
  54
  55  Server:
  56    host1 $ ./gdbus-example-peer --server --address tcp:host=0.0.0.0 --allow-anonymous
  57    Server is listening at: tcp:host=0.0.0.0,port=59556
  58    Client connected.
  59    Peer credentials: (no credentials received)
  60    Negotiated capabilities: unix-fd-passing=0
  61    Client said: Hey, it's 1273093652 already!
  62
  63  Client:
  64    host2 $ ./gdbus-example-peer -a tcp:host=host1,port=59556
  65    Connected.
  66    Negotiated capabilities: unix-fd-passing=0
  67    Server said: You said 'Hey, it's 1273093652 already!'. KTHXBYE!
  68
  69  */
  70
  71 #include <gio/gio.h>
  72 #include <stdlib.h>
  73
  74 /* ---------------------------------------------------------------------------------------------------- */
  75
  76 static GDBusNodeInfo *introspection_data = NULL;
  77
  78 /* Introspection data for the service we are exporting */
  79 static const gchar introspection_xml[] =
  80   "<node>"
  81   "  <interface name='org.gtk.GDBus.TestPeerInterface'>"
  82   "    <method name='HelloWorld'>"
  83   "      <arg type='s' name='greeting' direction='in'/>"
  84   "      <arg type='s' name='response' direction='out'/>"
  85   "    </method>"
  86   "  </interface>"
  87   "</node>";
  88
  89 /* ---------------------------------------------------------------------------------------------------- */
  90
  91 static void
  92 handle_method_call (GDBusConnection       *connection,
  93                     const gchar           *sender,
  94                     const gchar           *object_path,
  95                     const gchar           *interface_name,
  96                     const gchar           *method_name,
  97                     GVariant              *parameters,
  98                     GDBusMethodInvocation *invocation,
  99                     gpointer               user_data)
 100 {
 101   if (g_strcmp0 (method_name, "HelloWorld") == 0)
 102     {
 103       const gchar *greeting;
 104       gchar *response;
 105
 106       g_variant_get (parameters, "(&s)", &greeting);
 107       response = g_strdup_printf ("You said '%s'. KTHXBYE!", greeting);
 108       g_dbus_method_invocation_return_value (invocation,
 109                                              g_variant_new ("(s)", response));
 110       g_free (response);
 111       g_print ("Client said: %s\n", greeting);
 112     }
 113 }
 114
 115 static const GDBusInterfaceVTable interface_vtable =
 116 {
 117   handle_method_call,
 118   NULL,
 119   NULL,
 120   { 0 }
 121 };
 122
 123 /* ---------------------------------------------------------------------------------------------------- */
 124
 125 static void
 126 connection_closed (GDBusConnection *connection,
 127                    gboolean remote_peer_vanished,
 128                    GError *Error,
 129                    gpointer user_data)
 130 {
 131   g_print ("Client disconnected.\n");
 132   g_object_unref (connection);
 133 }
 134
 135 static gboolean
 136 on_new_connection (GDBusServer *server,
 137                    GDBusConnection *connection,
 138                    gpointer user_data)
 139 {
 140   guint registration_id;
 141   GCredentials *credentials;
 142   gchar *s;
 143
 144   credentials = g_dbus_connection_get_peer_credentials (connection);
 145   if (credentials == NULL)
 146     s = g_strdup ("(no credentials received)");
 147   else
 148     s = g_credentials_to_string (credentials);
 149
 150   g_print ("Client connected.\n"
 151            "Peer credentials: %s\n"
 152            "Negotiated capabilities: unix-fd-passing=%d\n",
 153            s,
 154            g_dbus_connection_get_capabilities (connection) & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING);
 155
 156   g_object_ref (connection);
 157   g_signal_connect (connection, "closed", G_CALLBACK (connection_closed), NULL);
 158   registration_id = g_dbus_connection_register_object (connection,
 159                                                        "/org/gtk/GDBus/TestObject",
 160                                                        introspection_data->interfaces[0],
 161                                                        &interface_vtable,
 162                                                        NULL,  /* user_data */
 163                                                        NULL,  /* user_data_free_func */
 164                                                        NULL); /* GError** */
 165   g_assert (registration_id > 0);
 166
 167   g_free (s);
 168
 169   return TRUE;
 170 }
 171
 172 /* ---------------------------------------------------------------------------------------------------- */
 173
 174 static gboolean
 175 allow_mechanism_cb (GDBusAuthObserver *observer,
 176                     const gchar *mechanism,
 177                     G_GNUC_UNUSED gpointer user_data)
 178 {
 179   /*
 180    * In a production GDBusServer that only needs to work on modern Unix
 181    * platforms, consider requiring EXTERNAL (credentials-passing),
 182    * which is the recommended authentication mechanism for AF_UNIX
 183    * sockets:
 184    *
 185    * if (g_strcmp0 (mechanism, "EXTERNAL") == 0)
 186    *   return TRUE;
 187    *
 188    * return FALSE;
 189    *
 190    * For this example we accept everything.
 191    */
 192
 193   g_print ("Considering whether to accept %s authentication...\n", mechanism);
 194   return TRUE;
 195 }
 196
 197 static gboolean
 198 authorize_authenticated_peer_cb (GDBusAuthObserver *observer,
 199                                  G_GNUC_UNUSED GIOStream *stream,
 200                                  GCredentials *credentials,
 201                                  G_GNUC_UNUSED gpointer user_data)
 202 {
 203   gboolean authorized = FALSE;
 204
 205   g_print ("Considering whether to authorize authenticated peer...\n");
 206
 207   if (credentials != NULL)
 208     {
 209       GCredentials *own_credentials;
 210       gchar *credentials_string = NULL;
 211
 212       credentials_string = g_credentials_to_string (credentials);
 213       g_print ("Peer's credentials: %s\n", credentials_string);
 214       g_free (credentials_string);
 215
 216       own_credentials = g_credentials_new ();
 217
 218       credentials_string = g_credentials_to_string (own_credentials);
 219       g_print ("Server's credentials: %s\n", credentials_string);
 220       g_free (credentials_string);
 221
 222       if (g_credentials_is_same_user (credentials, own_credentials, NULL))
 223         authorized = TRUE;
 224
 225       g_object_unref (own_credentials);
 226     }
 227
 228   if (!authorized)
 229     {
 230       /* In most servers you'd want to reject this, but for this example
 231        * we allow it. */
 232       g_print ("A server would often not want to authorize this identity\n");
 233       g_print ("Authorizing it anyway for demonstration purposes\n");
 234       authorized = TRUE;
 235     }
 236
 237   return authorized;
 238 }
 239
 240 /* ---------------------------------------------------------------------------------------------------- */
 241
 242 int
 243 main (int argc, char *argv[])
 244 {
 245   gint ret;
 246   gboolean opt_server;
 247   gchar *opt_address;
 248   GOptionContext *opt_context;
 249   gboolean opt_allow_anonymous;
 250   GError *error;
 251   GOptionEntry opt_entries[] =
 252     {
 253       { "server", 's', 0, G_OPTION_ARG_NONE, &opt_server, "Start a server instead of a client", NULL },
 254       { "address", 'a', 0, G_OPTION_ARG_STRING, &opt_address, "D-Bus address to use", NULL },
 255       { "allow-anonymous", 'n', 0, G_OPTION_ARG_NONE, &opt_allow_anonymous, "Allow anonymous authentication", NULL },
 256       G_OPTION_ENTRY_NULL
 257     };
 258
 259   ret = 1;
 260
 261   opt_address = NULL;
 262   opt_server = FALSE;
 263   opt_allow_anonymous = FALSE;
 264
 265   opt_context = g_option_context_new ("peer-to-peer example");
 266   error = NULL;
 267   g_option_context_add_main_entries (opt_context, opt_entries, NULL);
 268   if (!g_option_context_parse (opt_context, &argc, &argv, &error))
 269     {
 270       g_option_context_free (opt_context);
 271       g_printerr ("Error parsing options: %s\n", error->message);
 272       g_error_free (error);
 273       goto out;
 274     }
 275
 276   g_option_context_free (opt_context);
 277
 278   if (opt_address == NULL)
 279     {
 280       g_printerr ("Incorrect usage, try --help.\n");
 281       goto out;
 282     }
 283   if (!opt_server && opt_allow_anonymous)
 284     {
 285       g_printerr ("The --allow-anonymous option only makes sense when used with --server.\n");
 286       goto out;
 287     }
 288
 289   /* We are lazy here - we don't want to manually provide
 290    * the introspection data structures - so we just build
 291    * them from XML.
 292    */
 293   introspection_data = g_dbus_node_info_new_for_xml (introspection_xml, NULL);
 294   g_assert (introspection_data != NULL);
 295
 296   if (opt_server)
 297     {
 298       GDBusAuthObserver *observer;
 299       GDBusServer *server;
 300       gchar *guid;
 301       GMainLoop *loop;
 302       GDBusServerFlags server_flags;
 303
 304       guid = g_dbus_generate_guid ();
 305
 306       server_flags = G_DBUS_SERVER_FLAGS_NONE;
 307       if (opt_allow_anonymous)
 308         server_flags |= G_DBUS_SERVER_FLAGS_AUTHENTICATION_ALLOW_ANONYMOUS;
 309
 310       observer = g_dbus_auth_observer_new ();
 311       g_signal_connect (observer, "allow-mechanism", G_CALLBACK (allow_mechanism_cb), NULL);
 312       g_signal_connect (observer, "authorize-authenticated-peer", G_CALLBACK (authorize_authenticated_peer_cb), NULL);
 313
 314       error = NULL;
 315       server = g_dbus_server_new_sync (opt_address,
 316                                        server_flags,
 317                                        guid,
 318                                        observer,
 319                                        NULL, /* GCancellable */
 320                                        &error);
 321       g_dbus_server_start (server);
 322
 323       g_object_unref (observer);
 324       g_free (guid);
 325
 326       if (server == NULL)
 327         {
 328           g_printerr ("Error creating server at address %s: %s\n", opt_address, error->message);
 329           g_error_free (error);
 330           goto out;
 331         }
 332       g_print ("Server is listening at: %s\n", g_dbus_server_get_client_address (server));
 333       g_signal_connect (server,
 334                         "new-connection",
 335                         G_CALLBACK (on_new_connection),
 336                         NULL);
 337
 338       loop = g_main_loop_new (NULL, FALSE);
 339       g_main_loop_run (loop);
 340
 341       g_object_unref (server);
 342       g_main_loop_unref (loop);
 343     }
 344   else
 345     {
 346       GDBusConnection *connection;
 347       const gchar *greeting_response;
 348       GVariant *value;
 349       gchar *greeting;
 350
 351       error = NULL;
 352       connection = g_dbus_connection_new_for_address_sync (opt_address,
 353                                                            G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT,
 354                                                            NULL, /* GDBusAuthObserver */
 355                                                            NULL, /* GCancellable */
 356                                                            &error);
 357       if (connection == NULL)
 358         {
 359           g_printerr ("Error connecting to D-Bus address %s: %s\n", opt_address, error->message);
 360           g_error_free (error);
 361           goto out;
 362         }
 363
 364       g_print ("Connected.\n"
 365                "Negotiated capabilities: unix-fd-passing=%d\n",
 366                g_dbus_connection_get_capabilities (connection) & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING);
 367
 368       greeting = g_strdup_printf ("Hey, it's %" G_GINT64_FORMAT " already!",
 369                                   g_get_real_time () / G_USEC_PER_SEC);
 370       value = g_dbus_connection_call_sync (connection,
 371                                            NULL, /* bus_name */
 372                                            "/org/gtk/GDBus/TestObject",
 373                                            "org.gtk.GDBus.TestPeerInterface",
 374                                            "HelloWorld",
 375                                            g_variant_new ("(s)", greeting),
 376                                            G_VARIANT_TYPE ("(s)"),
 377                                            G_DBUS_CALL_FLAGS_NONE,
 378                                            -1,
 379                                            NULL,
 380                                            &error);
 381       g_free (greeting);
 382
 383       if (value == NULL)
 384         {
 385           g_printerr ("Error invoking HelloWorld(): %s\n", error->message);
 386           g_error_free (error);
 387           goto out;
 388         }
 389       g_variant_get (value, "(&s)", &greeting_response);
 390       g_print ("Server said: %s\n", greeting_response);
 391       g_variant_unref (value);
 392
 393       g_object_unref (connection);
 394     }
 395   g_dbus_node_info_unref (introspection_data);
 396
 397   ret = 0;
 398
 399  out:
 400   g_free (opt_address);
 401
 402   return ret;
 403 }