Add minimal soundbox Go package

This only adds the `Soundbox` struct type which has a `net.HardwareAddr`
to identify it together with a constructor and a unit test.

2 files changed, 50 insertions, 0 deletions

diff --git a/soundbox/soundbox.go b/soundbox/soundbox.go
new file mode 100644
index 0000000..fcabcdc
--- /dev/null
+++ b/soundbox/soundbox.go
@@ -0,0 +1,25 @@
+package soundbox
+
+import (
+	"fmt"
+	"net"
+)
+
+type Soundbox struct {
+	HardwareAddr net.HardwareAddr
+}
+
+func NewSoundbox(mac string) (Soundbox, error) {
+	hardwareAddr, err := net.ParseMAC(mac)
+	if err != nil {
+		return Soundbox{}, err
+	}
+	
+	if len(hardwareAddr) != 6 {
+		return Soundbox{}, fmt.Errorf("Only IEEE 802 MAC-48 addresses supported")
+	}
+
+	return Soundbox{
+		HardwareAddr: hardwareAddr,
+	}, nil
+}
diff --git a/soundbox/soundbox_test.go b/soundbox/soundbox_test.go
new file mode 100644
index 0000000..6a5cde3
--- /dev/null
+++ b/soundbox/soundbox_test.go
@@ -0,0 +1,25 @@
+package soundbox
+
+import (
+	"testing"
+)
+
+func TestNewSoundbox(t *testing.T) {
+	// valid MAC should succeed
+	_, err := NewSoundbox("12:34:56:ab:cd:ef")
+	if err != nil {
+		t.Errorf("NewSoundbox() failed: %v", err)
+	}
+
+	// invalid MAC should fail
+	_, err = NewSoundbox("12:34:56:ab:cd")
+	if err == nil {
+		t.Errorf("NewSoundbox() failed: %v", err)
+	}
+
+	// No EUI-64 supported
+	_, err = NewSoundbox("12:34:56:ab:cd:ef:12:45")
+	if err == nil {
+		t.Errorf("NewSoundbox() failed: %v", err)
+	}
+}