device: add nm_device_get_type_desc_for_log()

When logging, messages include the interface name to specify what
device they refer to. In most case the interface name is unique.

There are some devices that don't have a kernel link associated, and
their interface name is not guaranteed to be unique. This is currently
the case for OVS bridges and OVS ports. When reading a log with
duplicate interface names, it is difficult to understand what is
happening. And this is made worse by the fact that it is common
practice to assign the same name to all devices in a OVS hierarchy
(bridge, port, interface).

To make logs unambiguous, we want to print the device type together
with the name; however we don't want to *always* print the type
because in most cases it's not useful and it would consume valuable
real estate on the screen. Adopt a simple heuristic of showing the
type only for OVS devices.

This commit adds a helper function to return the device type to show
in logs, when it is needed.

2 files changed, 19 insertions, 0 deletions

diff --git a/src/core/devices/nm-device.c b/src/core/devices/nm-device.c
index edd8ef5f13..6c9f93808c 100644
--- a/src/core/devices/nm-device.c
+++ b/src/core/devices/nm-device.c
@@ -5400,6 +5400,24 @@ nm_device_get_type_desc(NMDevice *self)
 }
 
 const char *
+nm_device_get_type_desc_for_log(NMDevice *self)
+{
+    const char *type;
+
+    type = nm_device_get_type_desc(self);
+
+    /* Some OVS device types (ports and bridges) are not backed by a kernel link, and
+     * they can have the same name of another device of a different type. In fact, it's
+     * quite common to assign the same name to the OVS bridge, the OVS port and the OVS
+     * interface. For this reason, also log the type in case of OVS devices to make the
+     * log message unambiguous. */
+    if (NM_STR_HAS_PREFIX(type, "Open vSwitch"))
+        return type;
+
+    return NULL;
+}
+
+const char *
 nm_device_get_type_description(NMDevice *self)
 {
     g_return_val_if_fail(self != NULL, NULL);
diff --git a/src/core/devices/nm-device.h b/src/core/devices/nm-device.h
index e22dbd07a9..35a8d1cd49 100644
--- a/src/core/devices/nm-device.h
+++ b/src/core/devices/nm-device.h
@@ -463,6 +463,7 @@ int          nm_device_get_ip_ifindex(const NMDevice *dev);
 const char  *nm_device_get_driver(NMDevice *dev);
 const char  *nm_device_get_driver_version(NMDevice *dev);
 const char  *nm_device_get_type_desc(NMDevice *dev);
+const char  *nm_device_get_type_desc_for_log(NMDevice *dev);
 const char  *nm_device_get_type_description(NMDevice *dev);
 NMDeviceType nm_device_get_device_type(NMDevice *dev);
 NMLinkType   nm_device_get_link_type(NMDevice *dev);