Harden NIC probing for empty SFP ports

audit/internal/collector/nic_telemetry_test.go

@@ -57,6 +57,7 @@ func TestEnrichPCIeWithNICTelemetryAddsSerialFallback(t *testing.T) {
 	origReadMAC := readNetAddressFile
 	origEth := ethtoolInfoQuery
 	origModule := ethtoolModuleQuery
+	origCarrier := readNetCarrierFile
 	t.Cleanup(func() {
 		queryPCILSPCIDetail = origDetail
 		readPCIVPDFile = origVPD
@@ -64,6 +65,7 @@ func TestEnrichPCIeWithNICTelemetryAddsSerialFallback(t *testing.T) {
 		readNetAddressFile = origReadMAC
 		ethtoolInfoQuery = origEth
 		ethtoolModuleQuery = origModule
+		readNetCarrierFile = origCarrier
 	})
 
 	queryPCILSPCIDetail = func(bdf string) (string, error) {
@@ -82,6 +84,7 @@ func TestEnrichPCIeWithNICTelemetryAddsSerialFallback(t *testing.T) {
 		}
 		return "aa:bb:cc:dd:ee:ff", nil
 	}
+	readNetCarrierFile = func(string) (string, error) { return "1", nil }
 	ethtoolInfoQuery = func(string) (string, error) { return "", fmt.Errorf("skip firmware") }
 	ethtoolModuleQuery = func(string) (string, error) { return "", fmt.Errorf("skip optics") }
 
@@ -101,6 +104,42 @@ func TestEnrichPCIeWithNICTelemetryAddsSerialFallback(t *testing.T) {
 	}
 }
 
+func TestEnrichPCIeWithNICTelemetrySkipsModuleQueryWithoutCarrier(t *testing.T) {
+	origIfaces := netIfacesByBDF
+	origReadMAC := readNetAddressFile
+	origEth := ethtoolInfoQuery
+	origModule := ethtoolModuleQuery
+	origCarrier := readNetCarrierFile
+	t.Cleanup(func() {
+		netIfacesByBDF = origIfaces
+		readNetAddressFile = origReadMAC
+		ethtoolInfoQuery = origEth
+		ethtoolModuleQuery = origModule
+		readNetCarrierFile = origCarrier
+	})
+
+	netIfacesByBDF = func(string) []string { return []string{"eth0"} }
+	readNetAddressFile = func(string) (string, error) { return "aa:bb:cc:dd:ee:ff", nil }
+	readNetCarrierFile = func(string) (string, error) { return "0", nil }
+	ethtoolInfoQuery = func(string) (string, error) { return "", fmt.Errorf("skip firmware") }
+	ethtoolModuleQuery = func(string) (string, error) {
+		t.Fatal("ethtool -m should not be called without carrier")
+		return "", nil
+	}
+
+	class := "EthernetController"
+	bdf := "0000:18:00.0"
+	devs := []schema.HardwarePCIeDevice{{
+		DeviceClass: &class,
+		BDF:         &bdf,
+	}}
+
+	out := enrichPCIeWithNICTelemetry(devs)
+	if len(out[0].MacAddresses) != 1 || out[0].MacAddresses[0] != "aa:bb:cc:dd:ee:ff" {
+		t.Fatalf("mac_addresses=%v", out[0].MacAddresses)
+	}
+}
+
 func TestDBMValue(t *testing.T) {
 	tests := []struct {
 		in   string