From f3dc1621bc4e05e8f91b0460b837b08b35abc6b8 Mon Sep 17 00:00:00 2001
From: Richard Hughes <richard@hughsie.com>
Date: Wed, 27 Mar 2019 12:48:39 +0000
Subject: [PATCH] Shut down the daemon if the on-disk binary is replaced

If we update fwupd 'live' rather than from an ostree or offline update then
kill the running instance unless a firmware update is ongoing.

When users update fwupd at runtime they often forget to restart the fwupd daemon
and say that the update didn't fix it when actually they using the the old code.
---
 src/fu-main.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/src/fu-main.c b/src/fu-main.c
index d4cf93d54..4a7e6cf8e 100644
--- a/src/fu-main.c
+++ b/src/fu-main.c
@@ -41,6 +41,7 @@ typedef struct {
 	GDBusNodeInfo		*introspection_daemon;
 	GDBusProxy		*proxy_uid;
 	GMainLoop		*loop;
+	GFileMonitor		*argv0_monitor;
 	PolkitAuthority		*authority;
 	guint			 owner_id;
 	FuEngine		*engine;
@@ -1416,6 +1417,21 @@ fu_main_timed_exit_cb (gpointer user_data)
 	return G_SOURCE_REMOVE;
 }
 
+static void
+fu_main_argv_changed_cb (GFileMonitor *monitor, GFile *file, GFile *other_file,
+			 GFileMonitorEvent event_type, gpointer user_data)
+{
+	FuMainPrivate *priv = (FuMainPrivate *) user_data;
+
+	/* can do straight away? */
+	if (priv->update_in_progress) {
+		g_warning ("binary changed during a firmware update, ignoring");
+		return;
+	}
+	g_debug ("binary changed, shutting down");
+	g_main_loop_quit (priv->loop);
+}
+
 static GDBusNodeInfo *
 fu_main_load_introspection (const gchar *filename, GError **error)
 {
@@ -1450,6 +1466,8 @@ fu_main_private_free (FuMainPrivate *priv)
 		g_object_unref (priv->connection);
 	if (priv->authority != NULL)
 		g_object_unref (priv->authority);
+	if (priv->argv0_monitor != NULL)
+		g_object_unref (priv->argv0_monitor);
 	if (priv->introspection_daemon != NULL)
 		g_dbus_node_info_unref (priv->introspection_daemon);
 	g_free (priv);
@@ -1476,6 +1494,7 @@ main (int argc, char *argv[])
 	};
 	g_autoptr(FuMainPrivate) priv = NULL;
 	g_autoptr(GError) error = NULL;
+	g_autoptr(GFile) argv0_file = g_file_new_for_path (argv[0]);
 	g_autoptr(GOptionContext) context = NULL;
 
 	setlocale (LC_ALL, "");
@@ -1529,6 +1548,12 @@ main (int argc, char *argv[])
 				SIGTERM, fu_main_sigterm_cb,
 				priv, NULL);
 
+	/* restart the daemon if the binary gets replaced */
+	priv->argv0_monitor = g_file_monitor_file (argv0_file, G_FILE_MONITOR_NONE,
+						   NULL, &error);
+	g_signal_connect (priv->argv0_monitor, "changed",
+			  G_CALLBACK (fu_main_argv_changed_cb), priv);
+
 	/* load introspection from file */
 	priv->introspection_daemon = fu_main_load_introspection (FWUPD_DBUS_INTERFACE ".xml",
 								 &error);