secret-agent: rework handling of asynchronous request and cancellingth/secret-agent-rh1063036

Also use an opaque type NMSecretAgentCallId for the call-id.

NMSecretManager has the following properties:

- the callback will *always* be invoked exactly once. Even if you cancel
  the call or if you dispose NMSecretManager with pending calls.
  That allows the caller to rely on being called back (and possibly
  do some cleanup).

- Now you can cancel all 3 types of operations, not only 'GetSecrets'
  call. Note that this will still not cancel the calls 'DeleteSecrets'
  and 'SaveSecrets' on a D-Bus level.
  When cancelling, the callback will be invoked synchronously, with an
  GError indicating the cancelling (G_IO_ERROR_CANCELLED).

- During dispose, the callback is also invoked synchronously, with
  some other error reason.

- Otherwise, callbacks are always invoked asynchronously.

- Don't strip_remote_error from NMSecretManager. NMAgentManager inspects
  the remote error for the 'GetSecrets' call. Any users of
  NMSecretManager should strip the error themselves (as they see fit).

3 files changed, 211 insertions, 99 deletions

diff --git a/src/settings/nm-agent-manager.c b/src/settings/nm-agent-manager.c
index 34c2fecce1..7e1704e629 100644
--- a/src/settings/nm-agent-manager.c
+++ b/src/settings/nm-agent-manager.c
@@ -396,7 +396,7 @@ struct _Request {
 
 	/* Current agent being asked for secrets */
 	NMSecretAgent *current;
-	gconstpointer current_call_id;
+	NMSecretAgentCallId current_call_id;
 
 	/* Stores the sorted list of NMSecretAgents which will be asked for secrets */
 	GSList *pending;
@@ -585,9 +585,12 @@ request_next_agent (Request *req)
 {
 	GError *error = NULL;
 
-	req->current_call_id = NULL;
-	if (req->current)
-		g_object_unref (req->current);
+	if (req->current) {
+		if (req->current_call_id)
+			nm_secret_agent_cancel_secrets (req->current, req->current_call_id);
+		g_clear_object (&req->current);
+	}
+	g_warn_if_fail (!req->current_call_id);
 
 	if (req->pending) {
 		/* Send the request to the next agent */
@@ -600,8 +603,6 @@ request_next_agent (Request *req)
 
 		req->next_callback (req);
 	} else {
-		req->current = NULL;
-
 		/* No more secret agents are available to fulfill this secrets request */
 		error = g_error_new_literal (NM_AGENT_MANAGER_ERROR,
 		                             NM_AGENT_MANAGER_ERROR_NO_SECRETS,
@@ -770,7 +771,7 @@ connection_request_new_other (NMConnection *connection,
 
 static void
 get_done_cb (NMSecretAgent *agent,
-             gconstpointer call_id,
+             NMSecretAgentCallId call_id,
              GVariant *secrets,
              GError *error,
              gpointer user_data)
@@ -783,13 +784,22 @@ get_done_cb (NMSecretAgent *agent,
 	char *agent_uname = NULL;
 
 	g_return_if_fail (call_id == parent->current_call_id);
+	g_return_if_fail (agent == parent->current);
+
+	parent->current_call_id = NULL;
 
 	if (error) {
-		nm_log_dbg (LOGD_AGENTS, "(%s) agent failed secrets request %p/%s/%s: (%d) %s",
+		if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
+			nm_log_dbg (LOGD_AGENTS, "(%s) get secrets request cancelled: %p/%s/%s",
+			            nm_secret_agent_get_description (agent),
+			            req, parent->detail, req->setting_name);
+			return;
+		}
+
+		nm_log_dbg (LOGD_AGENTS, "(%s) agent failed secrets request %p/%s/%s: %s",
 		            nm_secret_agent_get_description (agent),
 		            req, parent->detail, req->setting_name,
-		            error ? error->code : -1,
-		            (error && error->message) ? error->message : "(unknown)");
+		            error->message);
 
 		if (_nm_dbus_error_has_name (error, NM_DBUS_INTERFACE_SECRET_AGENT ".UserCanceled")) {
 			error = g_error_new_literal (NM_AGENT_MANAGER_ERROR,
@@ -800,6 +810,7 @@ get_done_cb (NMSecretAgent *agent,
 		} else {
 			/* Try the next agent */
 			request_next_agent (parent);
+			g_dbus_error_strip_remote_error (error);
 			maybe_remove_agent_on_error (agent, error);
 		}
 		return;
@@ -900,9 +911,8 @@ get_agent_request_secrets (ConnectionRequest *req, gboolean include_system_secre
 	                                                       req->flags,
 	                                                       get_done_cb,
 	                                                       req);
-	if (parent->current_call_id == NULL) {
-		/* Shouldn't hit this, but handle it anyway */
-		g_warn_if_fail (parent->current_call_id != NULL);
+	if (!parent->current_call_id) {
+		g_warn_if_reached ();
 		request_next_agent (parent);
 	}
 
@@ -1220,7 +1230,7 @@ nm_agent_manager_cancel_secrets (NMAgentManager *self,
 
 static void
 save_done_cb (NMSecretAgent *agent,
-              gconstpointer call_id,
+              NMSecretAgentCallId call_id,
               GVariant *secrets,
               GError *error,
               gpointer user_data)
@@ -1230,15 +1240,25 @@ save_done_cb (NMSecretAgent *agent,
 	const char *agent_dbus_owner;
 
 	g_return_if_fail (call_id == parent->current_call_id);
+	g_return_if_fail (agent == parent->current);
+
+	parent->current_call_id = NULL;
 
 	if (error) {
-		nm_log_dbg (LOGD_AGENTS, "(%s) agent failed save secrets request %p/%s: (%d) %s",
+		if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
+			nm_log_dbg (LOGD_AGENTS, "(%s) save secrets request cancelled: %p/%s",
+			            nm_secret_agent_get_description (agent),
+			            req, parent->detail);
+			return;
+		}
+
+		nm_log_dbg (LOGD_AGENTS, "(%s) agent failed save secrets request %p/%s: %s",
 		            nm_secret_agent_get_description (agent),
 		            req, parent->detail,
-		            error ? error->code : -1,
-		            (error && error->message) ? error->message : "(unknown)");
+		            error->message);
 		/* Try the next agent */
 		request_next_agent (parent);
+		g_dbus_error_strip_remote_error (error);
 		maybe_remove_agent_on_error (agent, error);
 		return;
 	}
@@ -1260,9 +1280,8 @@ save_next_cb (Request *parent)
 	                                                        req->connection,
 	                                                        save_done_cb,
 	                                                        req);
-	if (parent->current_call_id == NULL) {
-		/* Shouldn't hit this, but handle it anyway */
-		g_warn_if_fail (parent->current_call_id != NULL);
+	if (!parent->current_call_id) {
+		g_warn_if_reached ();
 		request_next_agent (parent);
 	}
 }
@@ -1315,20 +1334,28 @@ nm_agent_manager_save_secrets (NMAgentManager *self,
 
 static void
 delete_done_cb (NMSecretAgent *agent,
-              gconstpointer call_id,
-              GVariant *secrets,
-              GError *error,
-              gpointer user_data)
+                NMSecretAgentCallId call_id,
+                GVariant *secrets,
+                GError *error,
+                gpointer user_data)
 {
 	Request *req = user_data;
 
 	g_return_if_fail (call_id == req->current_call_id);
+	g_return_if_fail (agent == req->current);
+
+	req->current_call_id = NULL;
 
 	if (error) {
-		nm_log_dbg (LOGD_AGENTS, "(%s) agent failed delete secrets request %p/%s: (%d) %s",
+		if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
+			nm_log_dbg (LOGD_AGENTS, "(%s) delete secrets request cancelled: %p/%s",
+			            nm_secret_agent_get_description (agent), req, req->detail);
+			return;
+		}
+
+		nm_log_dbg (LOGD_AGENTS, "(%s) agent failed delete secrets request %p/%s: %s",
 		            nm_secret_agent_get_description (agent), req, req->detail,
-		            error ? error->code : -1,
-		            (error && error->message) ? error->message : "(unknown)");
+		            error->message);
 	} else {
 		nm_log_dbg (LOGD_AGENTS, "(%s) agent deleted secrets for request %p/%s",
 		            nm_secret_agent_get_description (agent), req, req->detail);
@@ -1336,8 +1363,10 @@ delete_done_cb (NMSecretAgent *agent,
 
 	/* Tell the next agent to delete secrets */
 	request_next_agent (req);
-	if (error)
+	if (error) {
+		g_dbus_error_strip_remote_error (error);
 		maybe_remove_agent_on_error (agent, error);
+	}
 }
 
 static void
@@ -1349,9 +1378,8 @@ delete_next_cb (Request *parent)
 	                                                          req->connection,
 	                                                          delete_done_cb,
 	                                                          req);
-	if (parent->current_call_id == NULL) {
-		/* Shouldn't hit this, but handle it anyway */
-		g_warn_if_fail (parent->current_call_id != NULL);
+	if (!parent->current_call_id) {
+		g_warn_if_reached ();
 		request_next_agent (parent);
 	}
 }
diff --git a/src/settings/nm-secret-agent.c b/src/settings/nm-secret-agent.c
index c2c220fd41..e86e6b31b1 100644
--- a/src/settings/nm-secret-agent.c
+++ b/src/settings/nm-secret-agent.c
@@ -63,14 +63,17 @@ static guint signals[LAST_SIGNAL] = { 0 };
 
 /*************************************************************/
 
-typedef struct {
+struct _NMSecretAgentCallId {
 	NMSecretAgent *agent;
 	GCancellable *cancellable;
 	char *path;
 	char *setting_name;
+	gboolean is_get_secrets;
 	NMSecretAgentCallback callback;
 	gpointer callback_data;
-} Request;
+};
+
+typedef struct _NMSecretAgentCallId Request;
 
 static Request *
 request_new (NMSecretAgent *agent,
@@ -96,10 +99,29 @@ request_free (Request *r)
 {
 	g_free (r->path);
 	g_free (r->setting_name);
-	g_object_unref (r->cancellable);
+	if (r->cancellable)
+		g_object_unref (r->cancellable);
 	g_slice_free (Request, r);
 }
 
+static gboolean
+request_check_return (Request *r)
+{
+	NMSecretAgentPrivate *priv;
+
+	if (!r->cancellable)
+		return FALSE;
+
+	g_return_val_if_fail (NM_IS_SECRET_AGENT (r->agent), FALSE);
+
+	priv = NM_SECRET_AGENT_GET_PRIVATE (r->agent);
+
+	if (!g_hash_table_remove (priv->requests, r))
+		g_return_val_if_reached (FALSE);
+
+	return TRUE;
+}
+
 /*************************************************************/
 
 const char *
@@ -262,24 +284,20 @@ get_callback (GObject *proxy,
               gpointer user_data)
 {
 	Request *r = user_data;
-	NMSecretAgentPrivate *priv = NM_SECRET_AGENT_GET_PRIVATE (r->agent);
-	GVariant *secrets = NULL;
-	GError *error = NULL;
 
-	if (!g_cancellable_is_cancelled (r->cancellable)) {
-		nmdbus_secret_agent_call_get_secrets_finish (priv->proxy, &secrets, result, &error);
-		if (error)
-			g_dbus_error_strip_remote_error (error);
+	if (request_check_return (r)) {
+		NMSecretAgentPrivate *priv = NM_SECRET_AGENT_GET_PRIVATE (r->agent);
+		gs_free_error GError *error = NULL;
+		gs_unref_variant GVariant *secrets = NULL;
 
+		nmdbus_secret_agent_call_get_secrets_finish (priv->proxy, &secrets, result, &error);
 		r->callback (r->agent, r, secrets, error, r->callback_data);
-		g_clear_pointer (&secrets, g_variant_unref);
-		g_clear_error (&error);
 	}
 
-	g_hash_table_remove (priv->requests, r);
+	request_free (r);
 }
 
-gconstpointer
+NMSecretAgentCallId
 nm_secret_agent_get_secrets (NMSecretAgent *self,
                              NMConnection *connection,
                              const char *setting_name,
@@ -307,6 +325,8 @@ nm_secret_agent_get_secrets (NMSecretAgent *self,
 	flags &= ~NM_SECRET_AGENT_GET_SECRETS_FLAG_NO_ERRORS;
 
 	r = request_new (self, nm_connection_get_path (connection), setting_name, callback, callback_data);
+	r->is_get_secrets = TRUE;
+	g_hash_table_add (priv->requests, r);
 	nmdbus_secret_agent_call_get_secrets (priv->proxy,
 	                                      dict,
 	                                      nm_connection_get_path (connection),
@@ -315,11 +335,12 @@ nm_secret_agent_get_secrets (NMSecretAgent *self,
 	                                      flags,
 	                                      r->cancellable,
 	                                      get_callback, r);
-	g_hash_table_insert (priv->requests, r, r);
 
 	return r;
 }
 
+/*************************************************************/
+
 static void
 cancel_done (GObject *proxy, GAsyncResult *result, gpointer user_data)
 {
@@ -327,33 +348,84 @@ cancel_done (GObject *proxy, GAsyncResult *result, gpointer user_data)
 	GError *error = NULL;
 
 	if (!nmdbus_secret_agent_call_cancel_get_secrets_finish (NMDBUS_SECRET_AGENT (proxy), result, &error)) {
-		g_dbus_error_strip_remote_error (error);
-		nm_log_dbg (LOGD_AGENTS, "(%s): agent failed to cancel secrets: %s",
-		            description, error->message);
+		nm_log_dbg (LOGD_AGENTS, "%s%s%s: agent failed to cancel secrets: %s",
+		            NM_PRINT_FMT_QUOTED (description, "(", description, ")", "???"),
+		            error->message);
 		g_clear_error (&error);
 	}
 
 	g_free (description);
 }
 
+static void
+do_cancel_secrets (NMSecretAgent *self, Request *r, gboolean disposing)
+{
+	NMSecretAgentPrivate *priv = NM_SECRET_AGENT_GET_PRIVATE (self);
+	GCancellable *cancellable;
+	NMSecretAgentCallback callback;
+	gpointer callback_data;
+
+	g_return_if_fail (r->agent == self);
+	g_return_if_fail (r->cancellable);
+
+	if (r->is_get_secrets) {
+		/* for GetSecrets call, we must cancel the request. */
+		nmdbus_secret_agent_call_cancel_get_secrets (priv->proxy,
+		                                             r->path, r->setting_name,
+		                                             NULL,
+		                                             cancel_done,
+		                                             g_strdup (nm_secret_agent_get_description (self)));
+	}
+
+	cancellable = r->cancellable;
+	callback = r->callback;
+	callback_data = r->callback_data;
+
+	/* During g_cancellable_cancel() the d-bus method might return synchronously.
+	 * Clear r->cancellable first, so that it doesn't actually do anything.
+	 * After that, @r might be already freed. */
+	r->cancellable = NULL;
+	g_cancellable_cancel (cancellable);
+	g_object_unref (cancellable);
+
+	/* Don't free the request @r. It will be freed when the d-bus call returns.
+	 * Only clear r->cancellable to indicate that the request was cancelled. */
+
+	if (callback) {
+		GError *error = NULL;
+
+		if (disposing) {
+			/* hijack an error code. G_IO_ERROR_CANCELLED is only used synchronously
+			 * when the user calls nm_act_request_cancel_secrets().
+			 * When the user disposes the instance, we also invoke the callback synchronously,
+			 * but with a different error-reason. */
+			g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_FAILED,
+		                         "Disposing NMSecretAgent instance");
+		} else {
+			g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_CANCELLED,
+			                     "Request cancelled");
+		}
+		/* @r might be a dangling pointer at this point. However, that is no problem
+		 * to pass it as (opaque) call_id. */
+		callback (self, r, NULL, error, callback_data);
+		g_error_free (error);
+	}
+}
+
 void
-nm_secret_agent_cancel_secrets (NMSecretAgent *self, gconstpointer call)
+nm_secret_agent_cancel_secrets (NMSecretAgent *self, NMSecretAgentCallId call_id)
 {
 	NMSecretAgentPrivate *priv;
-	Request *r = (gpointer) call;
+	Request *r = call_id;
 
-	g_return_if_fail (self != NULL);
-	priv = NM_SECRET_AGENT_GET_PRIVATE (self);
-	g_return_if_fail (priv->proxy != NULL);
-	g_return_if_fail (r != NULL);
+	g_return_if_fail (NM_IS_SECRET_AGENT (self));
+	g_return_if_fail (r);
 
-	g_cancellable_cancel (r->cancellable);
+	priv = NM_SECRET_AGENT_GET_PRIVATE (self);
+	if (!g_hash_table_remove (priv->requests, r))
+		g_return_if_reached ();
 
-	nmdbus_secret_agent_call_cancel_get_secrets (priv->proxy,
-	                                             r->path, r->setting_name,
-	                                             NULL,
-	                                             cancel_done,
-	                                             g_strdup (nm_secret_agent_get_description (self)));
+	do_cancel_secrets (self, r, FALSE);
 }
 
 /*************************************************************/
@@ -364,21 +436,19 @@ agent_save_cb (GObject *proxy,
                gpointer user_data)
 {
 	Request *r = user_data;
-	NMSecretAgentPrivate *priv = NM_SECRET_AGENT_GET_PRIVATE (r->agent);
-	GError *error = NULL;
 
-	if (!g_cancellable_is_cancelled (r->cancellable)) {
+	if (request_check_return (r)) {
+		NMSecretAgentPrivate *priv = NM_SECRET_AGENT_GET_PRIVATE (r->agent);
+		gs_free_error GError *error = NULL;
+
 		nmdbus_secret_agent_call_save_secrets_finish (priv->proxy, result, &error);
-		if (error)
-			g_dbus_error_strip_remote_error (error);
 		r->callback (r->agent, r, NULL, error, r->callback_data);
-		g_clear_error (&error);
 	}
 
-	g_hash_table_remove (priv->requests, r);
+	request_free (r);
 }
 
-gconstpointer
+NMSecretAgentCallId
 nm_secret_agent_save_secrets (NMSecretAgent *self,
                               NMConnection *connection,
                               NMSecretAgentCallback callback,
@@ -399,34 +469,36 @@ nm_secret_agent_save_secrets (NMSecretAgent *self,
 	dict = nm_connection_to_dbus (connection, NM_CONNECTION_SERIALIZE_ALL);
 
 	r = request_new (self, cpath, NULL, callback, callback_data);
+	g_hash_table_add (priv->requests, r);
 	nmdbus_secret_agent_call_save_secrets (priv->proxy,
 	                                       dict, cpath,
-	                                       NULL,
+	                                       NULL, /* cancelling the request does *not* cancel the D-Bus call. */
 	                                       agent_save_cb, r);
-	g_hash_table_insert (priv->requests, r, r);
 
 	return r;
 }
 
+/*************************************************************/
+
 static void
 agent_delete_cb (GObject *proxy,
                  GAsyncResult *result,
                  gpointer user_data)
 {
 	Request *r = user_data;
-	NMSecretAgentPrivate *priv = NM_SECRET_AGENT_GET_PRIVATE (r->agent);
-	GError *error = NULL;
 
-	if (!g_cancellable_is_cancelled (r->cancellable)) {
+	if (request_check_return (r)) {
+		NMSecretAgentPrivate *priv = NM_SECRET_AGENT_GET_PRIVATE (r->agent);
+		gs_free_error GError *error = NULL;
+
 		nmdbus_secret_agent_call_delete_secrets_finish (priv->proxy, result, &error);
 		r->callback (r->agent, r, NULL, error, r->callback_data);
-		g_clear_error (&error);
 	}
 
-	g_hash_table_remove (priv->requests, r);
+	request_free (r);
 }
 
-gconstpointer
+NMSecretAgentCallId
 nm_secret_agent_delete_secrets (NMSecretAgent *self,
                                 NMConnection *connection,
                                 NMSecretAgentCallback callback,
@@ -447,15 +519,17 @@ nm_secret_agent_delete_secrets (NMSecretAgent *self,
 	dict = nm_connection_to_dbus (connection, NM_CONNECTION_SERIALIZE_NO_SECRETS);
 
 	r = request_new (self, cpath, NULL, callback, callback_data);
+	g_hash_table_add (priv->requests, r);
 	nmdbus_secret_agent_call_delete_secrets (priv->proxy,
 	                                         dict, cpath,
-	                                         NULL,
+	                                         NULL, /* cancelling the request does *not* cancel the D-Bus call. */
 	                                         agent_delete_cb, r);
-	g_hash_table_insert (priv->requests, r, r);
 
 	return r;
 }
 
+/*************************************************************/
+
 static void
 name_owner_changed_cb (GObject *proxy,
                        GParamSpec *pspec,
@@ -532,14 +606,22 @@ nm_secret_agent_init (NMSecretAgent *self)
 {
 	NMSecretAgentPrivate *priv = NM_SECRET_AGENT_GET_PRIVATE (self);
 
-	priv->requests = g_hash_table_new_full (g_direct_hash, g_direct_equal,
-	                                        NULL, (GDestroyNotify) request_free);
+	priv->requests = g_hash_table_new (g_direct_hash, g_direct_equal);
 }
 
 static void
 dispose (GObject *object)
 {
-	NMSecretAgentPrivate *priv = NM_SECRET_AGENT_GET_PRIVATE (object);
+	NMSecretAgent *self = NM_SECRET_AGENT (object);
+	NMSecretAgentPrivate *priv = NM_SECRET_AGENT_GET_PRIVATE (self);
+	GHashTableIter iter;
+	Request *r;
+
+	g_hash_table_iter_init (&iter, priv->requests);
+	while (g_hash_table_iter_next (&iter, (gpointer *) &r, NULL)) {
+		g_hash_table_iter_remove (&iter);
+		do_cancel_secrets (self, r, TRUE);
+	}
 
 	g_clear_object (&priv->proxy);
 	g_clear_object (&priv->subject);
diff --git a/src/settings/nm-secret-agent.h b/src/settings/nm-secret-agent.h
index 7883979d5b..668b1e559c 100644
--- a/src/settings/nm-secret-agent.h
+++ b/src/settings/nm-secret-agent.h
@@ -43,6 +43,8 @@ typedef struct {
 	void (*disconnected) (NMSecretAgent *self);
 } NMSecretAgentClass;
 
+typedef struct _NMSecretAgentCallId *NMSecretAgentCallId;
+
 GType nm_secret_agent_get_type (void);
 
 NMSecretAgent *nm_secret_agent_new (GDBusMethodInvocation *context,
@@ -76,30 +78,30 @@ gboolean    nm_secret_agent_has_permission (NMSecretAgent *agent,
                                             const char *permission);
 
 typedef void (*NMSecretAgentCallback) (NMSecretAgent *agent,
-                                       gconstpointer call,
+                                       NMSecretAgentCallId call_id,
                                        GVariant *new_secrets, /* NULL for save & delete */
                                        GError *error,
                                        gpointer user_data);
 
-gconstpointer nm_secret_agent_get_secrets  (NMSecretAgent *agent,
-                                            NMConnection *connection,
-                                            const char *setting_name,
-                                            const char **hints,
-                                            NMSecretAgentGetSecretsFlags flags,
-                                            NMSecretAgentCallback callback,
-                                            gpointer callback_data);
+NMSecretAgentCallId nm_secret_agent_get_secrets  (NMSecretAgent *agent,
+                                                  NMConnection *connection,
+                                                  const char *setting_name,
+                                                  const char **hints,
+                                                  NMSecretAgentGetSecretsFlags flags,
+                                                  NMSecretAgentCallback callback,
+                                                  gpointer callback_data);
 
 void        nm_secret_agent_cancel_secrets (NMSecretAgent *agent,
-                                            gconstpointer call_id);
+                                            NMSecretAgentCallId call_id);
 
-gconstpointer nm_secret_agent_save_secrets (NMSecretAgent *agent,
-                                            NMConnection *connection,
-                                            NMSecretAgentCallback callback,
-                                            gpointer callback_data);
+NMSecretAgentCallId nm_secret_agent_save_secrets (NMSecretAgent *agent,
+                                                  NMConnection *connection,
+                                                  NMSecretAgentCallback callback,
+                                                  gpointer callback_data);
 
-gconstpointer nm_secret_agent_delete_secrets (NMSecretAgent *agent,
-                                              NMConnection *connection,
-                                              NMSecretAgentCallback callback,
-                                              gpointer callback_data);
+NMSecretAgentCallId nm_secret_agent_delete_secrets (NMSecretAgent *agent,
+                                                    NMConnection *connection,
+                                                    NMSecretAgentCallback callback,
+                                                    gpointer callback_data);
 
 #endif /* __NETWORKMANAGER_SECRET_AGENT_H__ */