1 files changed, 63 insertions, 0 deletions
diff --git a/software/communication/data_link.go b/software/communication/data_link.go
new file mode 100644
index 0000000..d6e752d
--- /dev/null
+++ b/software/communication/data_link.go
@@ -0,0 +1,63 @@
+package communication
+
+const (
+	SLIP_END         = 0xC0
+	SLIP_ESC         = 0xDB
+	SLIP_ESC_END     = 0xDC
+	SLIP_ESC_ESC     = 0xDD
+	SLIP_MAX_PAYLOAD = 1500
+)
+
+type dataLink struct {
+	rx chan []byte
+}
+
+func newDataLink() dataLink {
+	dl := dataLink{}
+
+	dl.rx = make(chan []byte)
+
+	return dl
+}
+
+func (dl *dataLink) start(source chan byte) {
+	go dl.receive(source)
+}
+
+func (dl *dataLink) receive(source chan byte) {
+	for {
+		frame := unslip(source)
+		dl.rx <- frame
+	}
+}
+
+func unslip(source chan byte) []byte {
+	escaped := false
+	buffer := make([]byte, 0)
+
+	for {
+		octet := <-source
+		if escaped {
+			switch octet {
+			case SLIP_ESC_END:
+				buffer = append(buffer, SLIP_END)
+			case SLIP_ESC_ESC:
+				buffer = append(buffer, SLIP_ESC)
+			}
+		} else {
+			switch octet {
+			case SLIP_END:
+				break
+			case SLIP_ESC:
+				escaped = true
+				continue
+			default:
+				buffer = append(buffer, octet)
+				continue
+			}
+			break
+		}
+	}
+
+	return buffer
+}