/*

Usage examples (modulo addresses / credentials).

UNIX domain socket transport:

 Server:

   $ ./gdbus-example-peer --server --address unix:abstract=myaddr

   Server is listening at: unix:abstract=myaddr

   Client connected.

   Peer credentials: GCredentials:unix-user=500,unix-group=500,unix-process=13378

   Negotiated capabilities: unix-fd-passing=1

   Client said: Hey, it's 1273093080 already!

 Client:

   $ ./gdbus-example-peer --address unix:abstract=myaddr

   Connected.

   Negotiated capabilities: unix-fd-passing=1

   Server said: You said 'Hey, it's 1273093080 already!'. KTHXBYE!

Nonce-secured TCP transport on the same host:

 Server:

   $ ./gdbus-example-peer --server --address nonce-tcp:

   Server is listening at: nonce-tcp:host=localhost,port=43077,noncefile=/tmp/gdbus-nonce-file-X1ZNCV

   Client connected.

   Peer credentials: (no credentials received)

   Negotiated capabilities: unix-fd-passing=0

   Client said: Hey, it's 1273093206 already!

 Client:

   $ ./gdbus-example-peer -address nonce-tcp:host=localhost,port=43077,noncefile=/tmp/gdbus-nonce-file-X1ZNCV

   Connected.

   Negotiated capabilities: unix-fd-passing=0

   Server said: You said 'Hey, it's 1273093206 already!'. KTHXBYE!

TCP transport on two different hosts with a shared home directory:

 Server:

   host1 $ ./gdbus-example-peer --server --address tcp:host=0.0.0.0

   Server is listening at: tcp:host=0.0.0.0,port=46314

   Client connected.

   Peer credentials: (no credentials received)

   Negotiated capabilities: unix-fd-passing=0

   Client said: Hey, it's 1273093337 already!

 Client:

   host2 $ ./gdbus-example-peer -a tcp:host=host1,port=46314

   Connected.

   Negotiated capabilities: unix-fd-passing=0

   Server said: You said 'Hey, it's 1273093337 already!'. KTHXBYE!

TCP transport on two different hosts without authentication:

 Server:

   host1 $ ./gdbus-example-peer --server --address tcp:host=0.0.0.0 --allow-anonymous

   Server is listening at: tcp:host=0.0.0.0,port=59556

   Client connected.

   Peer credentials: (no credentials received)

   Negotiated capabilities: unix-fd-passing=0

   Client said: Hey, it's 1273093652 already!

 Client:

   host2 $ ./gdbus-example-peer -a tcp:host=host1,port=59556

   Connected.

   Negotiated capabilities: unix-fd-passing=0

   Server said: You said 'Hey, it's 1273093652 already!'. KTHXBYE!

 */

#include <gio/gio.h>

#include <stdlib.h>

/* ---------------------------------------------------------------------------------------------------- */

static GDBusNodeInfo *introspection_data = NULL;

/* Introspection data for the service we are exporting */

static const gchar introspection_xml[] =

  "<node>"

  "  <interface name='org.gtk.GDBus.TestPeerInterface'>"

  "    <method name='HelloWorld'>"

  "      <arg type='s' name='greeting' direction='in'/>"

  "      <arg type='s' name='response' direction='out'/>"

  "    </method>"

  "  </interface>"

  "</node>";

/* ---------------------------------------------------------------------------------------------------- */

static void

handle_method_call (GDBusConnection       *connection,

                    const gchar           *sender,

                    const gchar           *object_path,

                    const gchar           *interface_name,

                    const gchar           *method_name,

                    GVariant              *parameters,

                    GDBusMethodInvocation *invocation,

                    gpointer               user_data)

{

  if (g_strcmp0 (method_name, "HelloWorld") == 0)

    {

      const gchar *greeting;

      gchar *response;

      g_variant_get (parameters, "(&s)", &greeting);

      response = g_strdup_printf ("You said '%s'. KTHXBYE!", greeting);

      g_dbus_method_invocation_return_value (invocation,

                                             g_variant_new ("(s)", response));

      g_free (response);

      g_print ("Client said: %s\n", greeting);

    }

}

static const GDBusInterfaceVTable interface_vtable =

{

  handle_method_call,

  NULL,

  NULL,

};

/* ---------------------------------------------------------------------------------------------------- */

static gboolean

on_new_connection (GDBusServer *server,

                   GDBusConnection *connection,

                   gpointer user_data)

{

  guint registration_id;

  GCredentials *credentials;

  gchar *s;

  credentials = g_dbus_connection_get_peer_credentials (connection);

  if (credentials == NULL)

    s = g_strdup ("(no credentials received)");

  else

    s = g_credentials_to_string (credentials);

  g_print ("Client connected.\n"

           "Peer credentials: %s\n"

           "Negotiated capabilities: unix-fd-passing=%d\n",

           s,

           g_dbus_connection_get_capabilities (connection) & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING);

  g_object_ref (connection);

  registration_id = g_dbus_connection_register_object (connection,

                                                       "/org/gtk/GDBus/TestObject",

                                                       introspection_data->interfaces[0],

                                                       &interface_vtable,

                                                       NULL,  /* user_data */

                                                       NULL,  /* user_data_free_func */

                                                       NULL); /* GError** */

  g_assert (registration_id > 0);

  return TRUE;

}

/* ---------------------------------------------------------------------------------------------------- */

int

main (int argc, char *argv[])

{

  gint ret;

  gboolean opt_server;

  gchar *opt_address;

  GOptionContext *opt_context;

  gboolean opt_allow_anonymous;

  GError *error;

  GOptionEntry opt_entries[] =

    {

      { "server", 's', 0, G_OPTION_ARG_NONE, &opt_server, "Start a server instead of a client", NULL },

      { "address", 'a', 0, G_OPTION_ARG_STRING, &opt_address, "D-Bus address to use", NULL },

      { "allow-anonymous", 'n', 0, G_OPTION_ARG_NONE, &opt_allow_anonymous, "Allow anonymous authentication", NULL },

      { NULL}

    };

  ret = 1;

  opt_address = NULL;

  opt_server = FALSE;

  opt_allow_anonymous = FALSE;

  opt_context = g_option_context_new ("peer-to-peer example");

  error = NULL;

  g_option_context_add_main_entries (opt_context, opt_entries, NULL);

  if (!g_option_context_parse (opt_context, &argc, &argv, &error))

    {

      g_printerr ("Error parsing options: %s\n", error->message);

      g_error_free (error);

      goto out;

    }

  if (opt_address == NULL)

    {

      g_printerr ("Incorrect usage, try --help.\n");

      goto out;

    }

  if (!opt_server && opt_allow_anonymous)

    {

      g_printerr ("The --allow-anonymous option only makes sense when used with --server.\n");

      goto out;

    }

  /* We are lazy here - we don't want to manually provide

   * the introspection data structures - so we just build

   * them from XML.

   */

  introspection_data = g_dbus_node_info_new_for_xml (introspection_xml, NULL);

  g_assert (introspection_data != NULL);

  if (opt_server)

    {

      GDBusServer *server;

      gchar *guid;

      GMainLoop *loop;

      GDBusServerFlags server_flags;

      guid = g_dbus_generate_guid ();

      server_flags = G_DBUS_SERVER_FLAGS_NONE;

      if (opt_allow_anonymous)

        server_flags |= G_DBUS_SERVER_FLAGS_AUTHENTICATION_ALLOW_ANONYMOUS;

      error = NULL;

      server = g_dbus_server_new_sync (opt_address,

                                       server_flags,

                                       guid,

                                       NULL, /* GDBusAuthObserver */

                                       NULL, /* GCancellable */

                                       &error);

      g_dbus_server_start (server);

      g_free (guid);

      if (server == NULL)

        {

          g_printerr ("Error creating server at address %s: %s\n", opt_address, error->message);

          g_error_free (error);

          goto out;

        }

      g_print ("Server is listening at: %s\n", g_dbus_server_get_client_address (server));

      g_signal_connect (server,

                        "new-connection",

                        G_CALLBACK (on_new_connection),

                        NULL);

      loop = g_main_loop_new (NULL, FALSE);

      g_main_loop_run (loop);

      g_object_unref (server);

      g_main_loop_unref (loop);

    }

  else

    {

      GDBusConnection *connection;

      const gchar *greeting_response;

      GVariant *value;

      gchar *greeting;

      error = NULL;

      connection = g_dbus_connection_new_for_address_sync (opt_address,

                                                           G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT,

                                                           NULL, /* GDBusAuthObserver */

                                                           NULL, /* GCancellable */

                                                           &error);

      if (connection == NULL)

        {

          g_printerr ("Error connecting to D-Bus address %s: %s\n", opt_address, error->message);

          g_error_free (error);

          goto out;

        }

      g_print ("Connected.\n"

               "Negotiated capabilities: unix-fd-passing=%d\n",

               g_dbus_connection_get_capabilities (connection) & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING);

      greeting = g_strdup_printf ("Hey, it's %" G_GUINT64_FORMAT " already!", (guint64) time (NULL));

      value = g_dbus_connection_call_sync (connection,

                                           NULL, /* bus_name */

                                           "/org/gtk/GDBus/TestObject",

                                           "org.gtk.GDBus.TestPeerInterface",

                                           "HelloWorld",

                                           g_variant_new ("(s)", greeting),

                                           G_VARIANT_TYPE ("(s)"),

                                           G_DBUS_CALL_FLAGS_NONE,

                                           -1,

                                           NULL,

                                           &error);

      if (value == NULL)

        {

          g_printerr ("Error invoking HelloWorld(): %s\n", error->message);

          g_error_free (error);

          goto out;

        }

      g_variant_get (value, "(&s)", &greeting_response);

      g_print ("Server said: %s\n", greeting_response);

      g_variant_unref (value);

      g_object_unref (connection);

    }

  g_dbus_node_info_unref (introspection_data);

  ret = 0;

 out:

  return ret;

}