From: Arvin Schnell <aschnell@suse.de>
Date: Thu, 11 Jun 2026 12:33:46 +0000 (+0200)
Subject: - improved error handling
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F1143%2Fhead;p=thirdparty%2Fsnapper.git

- improved error handling
---

diff --git a/dbus/DBusConnection.cc b/dbus/DBusConnection.cc
index 145d1d3d..4b290a23 100644
--- a/dbus/DBusConnection.cc
+++ b/dbus/DBusConnection.cc
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2012 Novell, Inc.
- * Copyright (c) 2023 SUSE LLC
+ * Copyright (c) [2023-2026] SUSE LLC
  *
  * All Rights Reserved.
  *
@@ -45,8 +45,10 @@ namespace DBus
 
 	if (!conn)
 	{
-	    SN_THROW(FatalException());
+	    SN_THROW(FatalException("dbus_bus_get() returned null"));
 	}
+
+	dbus_connection_set_exit_on_disconnect(conn, false);
     }
 
 
@@ -72,7 +74,7 @@ namespace DBus
 
 	if (ret != DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER)
 	{
-	    SN_THROW(FatalException());
+	    SN_THROW(FatalException("dbus_bus_request_name() failed"));
 	}
     }
 
@@ -84,7 +86,7 @@ namespace DBus
 
 	if (!dbus_connection_send(conn, m.get_message(), NULL))
 	{
-	    SN_THROW(FatalException());
+	    SN_THROW(FatalException("dbus_connection_send() failed"));
 	}
     }
 
@@ -120,7 +122,7 @@ namespace DBus
 	if (dbus_error_is_set(&err))
 	{
 	    dbus_error_free(&err);
-	    SN_THROW(FatalException());
+	    SN_THROW(FatalException("dbus_bus_add_match() failed"));
 	}
     }
 
@@ -137,7 +139,7 @@ namespace DBus
 	if (dbus_error_is_set(&err))
 	{
 	    dbus_error_free(&err);
-	    SN_THROW(FatalException());
+	    SN_THROW(FatalException("dbus_bus_remove_match() failed"));
 	}
     }
 
@@ -147,7 +149,20 @@ namespace DBus
     {
 	boost::lock_guard<boost::mutex> lock(mutex);
 
-	return dbus_connection_pop_message(conn);
+	DBusMessage* msg = dbus_connection_pop_message(conn);
+
+	// Being disconnected by dbus can be simulated with something like "strace -e
+	// fault=recvmsg:error=ECONNRESET:when=10+ /usr/sbin/snapperd --logger-type
+	// stdout".
+
+	if (msg &&
+	    strcmp(dbus_message_get_interface(msg), DBUS_INTERFACE_LOCAL) == 0 &&
+	    strcmp(dbus_message_get_member(msg), "Disconnected") == 0)
+	{
+	    throw FatalException("disconnected from dbus");
+	}
+
+	return msg;
     }
 
 
@@ -159,7 +174,7 @@ namespace DBus
 	const string sender = m.get_sender();
 	if (sender.empty())
 	{
-	    SN_THROW(FatalException());
+	    SN_THROW(FatalException("get_sender() returned empty sender"));
 	}
 
 	DBusError err;
diff --git a/dbus/DBusMessage.h b/dbus/DBusMessage.h
index d3d89912..6a8ee89a 100644
--- a/dbus/DBusMessage.h
+++ b/dbus/DBusMessage.h
@@ -77,6 +77,7 @@ namespace DBus
     struct FatalException : public Exception
     {
 	explicit FatalException() : Exception("dbus fatal exception") {}
+	explicit FatalException(const string& msg) : Exception("dbus fatal exception: " + msg) {}
     };
 
 
diff --git a/package/snapper.changes b/package/snapper.changes
index 3a3a702b..5de6a59d 100644
--- a/package/snapper.changes
+++ b/package/snapper.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Thu Jun 11 10:21:28 CEST 2026 - Arvin Schnell <aschnell@suse.com>
+
+- improved error handling when disconnected by dbus (see
+  gh#openSUSE/snapper#223)
+
 -------------------------------------------------------------------
 Wed Jun 10 09:13:13 CEST 2026 - Arvin Schnell <aschnell@suse.com>
 
diff --git a/server/snapperd.cc b/server/snapperd.cc
index d8091f1c..ecce5a2b 100644
--- a/server/snapperd.cc
+++ b/server/snapperd.cc
@@ -312,47 +312,47 @@ main(int argc, char** argv)
 
     signal(SIGPIPE, SIG_IGN);
 
-    dbus_threads_init_default();
+    try
+    {
+	dbus_threads_init_default();
 
-    MyMainLoop mainloop(DBUS_BUS_SYSTEM);
+	MyMainLoop mainloop(DBUS_BUS_SYSTEM);
 
-    mainloop.set_idle_timeout(idle_time);
+	mainloop.set_idle_timeout(idle_time);
 
-    y2mil("Requesting DBus name");
+	y2mil("Requesting DBus name");
 
-    try
-    {
 	mainloop.request_name(SERVICE, DBUS_NAME_FLAG_REPLACE_EXISTING);
-    }
-    catch (const Exception& e)
-    {
-	SN_CAUGHT(e);
 
-	y2err("Failed to request DBus name");
+	y2mil("Loading snapper configs");
 
-	return EXIT_FAILURE;
-    }
+	try
+	{
+	    meta_snappers.init();
+	}
+	catch (const Exception& e)
+	{
+	    SN_CAUGHT(e);
 
-    y2mil("Loading snapper configs");
+	    y2err("Failed to load snapper configs");
 
-    try
-    {
-	meta_snappers.init();
+	    return EXIT_FAILURE;
+	}
+
+	y2mil("Listening for method calls and signals");
+
+	mainloop.run();
+
+	y2mil("Exiting");
+
+	meta_snappers.unload();
     }
     catch (const Exception& e)
     {
 	SN_CAUGHT(e);
 
-	y2err("Failed to load snapper configs");
+	return EXIT_FAILURE;
     }
 
-    y2mil("Listening for method calls and signals");
-
-    mainloop.run();
-
-    y2mil("Exiting");
-
-    meta_snappers.unload();
-
     return EXIT_SUCCESS;
 }