netspeed: avoid glibtop warnings for non-existent network devicesnetspeed-missing-device-warnings

When a network interface is disabled at the kernel level, the applet
tries to read from a device that no longer exist, generating continuous
warning messages in syslog.

Check if the device exists before calling glibtop_get_netload in both
is_dummy_device and get_device_info. When the device doesn't exist,
get_device_info returns a non-running device info, allowing the existing
auto-change logic to find an active device.

Fixes #688

1 files changed, 15 insertions, 0 deletions

diff --git a/netspeed/src/backend.c b/netspeed/src/backend.c
index e1321497..cd369200 100644
--- a/netspeed/src/backend.c
+++ b/netspeed/src/backend.c
@@ -64,10 +64,20 @@ struct nl80211_state {
 
 #endif /* HAVE_NL */
 
+static gboolean
+device_exists (const char *device)
+{
+    return (if_nametoindex (device) != 0);
+}
+
 gboolean
 is_dummy_device (const char* device)
 {
     glibtop_netload netload;
+
+    if (!device_exists (device))
+        return TRUE;
+
     glibtop_get_netload (&netload, device);
 
     if (netload.if_flags & (1 << GLIBTOP_IF_FLAGS_LOOPBACK))
@@ -332,6 +342,11 @@ get_device_info (const char  *device,
     devinfo->name = g_strdup (device);
     devinfo->type = DEV_UNKNOWN;
 
+    /* Device doesn't exist.
+     * Return so the auto-change logic can find an active device. */
+    if (!device_exists (device))
+        return;
+
     glibtop_get_netload (&netload, device);
 
     devinfo->up = (netload.if_flags & (1L << GLIBTOP_IF_FLAGS_UP) ? TRUE : FALSE);