Checkpoint

controlblock.go

@@ -23,6 +23,40 @@ type ControlBlock struct {
 	Data         ControlBlockData
 }
 
+func (cb *ControlBlock) Bytes() ([]byte, error) {
+	var data = make([]byte, InfoSize)
+
+	if err := cb.Data.Write(data); err != nil {
+		return nil, err
+	}
+	if cb.Last {
+		data[0] |= B10000000
+	}
+
+	data[4] = uint8(cb.DstID >> 16)
+	data[5] = uint8(cb.DstID >> 8)
+	data[6] = uint8(cb.DstID)
+	data[7] = uint8(cb.SrcID >> 16)
+	data[8] = uint8(cb.SrcID >> 8)
+	data[9] = uint8(cb.SrcID)
+
+	// Calculate CRC16
+	for i := 0; i < 10; i++ {
+		crc16(&cb.CRC, data[i])
+	}
+	crc16end(&cb.CRC)
+
+	// Inverting according to the inversion polynomial.
+	cb.CRC = ^cb.CRC
+	// Applying CRC mask, see DMR AI spec. page 143.
+	cb.CRC ^= 0xa5a5
+
+	data[10] = uint8(cb.CRC >> 8)
+	data[11] = uint8(cb.CRC)
+
+	return data, nil
+}
+
 func (cb *ControlBlock) String() string {
 	if cb.Data == nil {
 		return fmt.Sprintf("CSBK, last %t, %d->%d, unknown (opcode %d)",
@@ -196,40 +230,6 @@ func (d *Preamble) Write(data []byte) error {
 
 var _ (ControlBlockData) = (*Preamble)(nil)
 
-func (cb *ControlBlock) Bytes() ([]byte, error) {
-	var data = make([]byte, InfoSize)
-
-	if err := cb.Data.Write(data); err != nil {
-		return nil, err
-	}
-	if cb.Last {
-		data[0] |= B10000000
-	}
-
-	data[4] = uint8(cb.DstID >> 16)
-	data[5] = uint8(cb.DstID >> 8)
-	data[6] = uint8(cb.DstID)
-	data[7] = uint8(cb.SrcID >> 16)
-	data[8] = uint8(cb.SrcID >> 8)
-	data[9] = uint8(cb.SrcID)
-
-	// Calculate CRC16
-	for i := 0; i < 10; i++ {
-		crc16(&cb.CRC, data[i])
-	}
-	crc16end(&cb.CRC)
-
-	// Inverting according to the inversion polynomial.
-	cb.CRC = ^cb.CRC
-	// Applying CRC mask, see DMR AI spec. page 143.
-	cb.CRC ^= 0xa5a5
-
-	data[10] = uint8(cb.CRC >> 8)
-	data[11] = uint8(cb.CRC)
-
-	return data, nil
-}
-
 func ParseControlBlock(data []byte) (*ControlBlock, error) {
 	if len(data) != InfoSize {
 		return nil, fmt.Errorf("dmr: expected %d info bytes, got %d", InfoSize, len(data))

crc.go

@@ -1,13 +1,6 @@
 package dmr
 
-const (
-	// G(x) = x^9+x^6+x^4+x^3+1
-	crc9poly = 0x59
-	// G(x) = x^16+x^12+x^5+1
-	crc16poly = 0x1021
-	crc32poly = 0x04c11db7
-)
-
+// G(x) = x^9+x^6+x^4+x^3+1
 func crc9(crc *uint16, b uint8, bits int) {
 	var v uint8 = 0x80
 	for i := 0; i < 8-bits; i++ {
@@ -22,7 +15,7 @@ func crc9(crc *uint16, b uint8, bits int) {
 			(*crc)++
 		}
 		if xor {
-			(*crc) ^= crc9poly
+			(*crc) ^= 0x0059
 		}
 		v >>= 1
 	}
@@ -35,32 +28,33 @@ func crc9end(crc *uint16, bits int) {
 		// Limit the number of shift registers to 9.
 		*crc &= 0x01ff
 		if xor {
-			(*crc) ^= crc9poly
+			(*crc) ^= 0x0059
 		}
 	}
 }
 
+// G(x) = x^16+x^12+x^5+1
 func crc16(crc *uint16, b byte) {
 	var v uint8 = 0x80
 	for i := 0; i < 8; i++ {
-		xor := ((*crc) & 0x8000) > 0
+		xor := ((*crc) & 0x8000) != 0
 		(*crc) <<= 1
 		if b&v > 0 {
 			(*crc)++
 		}
 		if xor {
-			(*crc) ^= crc16poly
+			(*crc) ^= 0x1021
 		}
 		v >>= 1
 	}
 }
 
 func crc16end(crc *uint16) {
 	for i := 0; i < 16; i++ {
-		xor := ((*crc) & 0x8000) > 0
+		xor := ((*crc) & 0x8000) != 0
 		(*crc) <<= 1
 		if xor {
-			(*crc) ^= crc16poly
+			(*crc) ^= 0x1021
 		}
 	}
 }
@@ -74,7 +68,7 @@ func crc32(crc *uint32, b byte) {
 			(*crc)++
 		}
 		if xor {
-			(*crc) ^= crc32poly
+			(*crc) ^= 0x04c11db7
 		}
 		v >>= 1
 	}
@@ -85,7 +79,7 @@ func crc32end(crc *uint32) {
 		xor := ((*crc) & 0x80000000) > 0
 		(*crc) <<= 1
 		if xor {
-			(*crc) ^= crc32poly
+			(*crc) ^= 0x04c11db7
 		}
 	}
 }

data.go

@@ -35,10 +35,7 @@ func ParseDataBlock(data []byte, dataType uint8, confirmed bool) (*DataBlock, er
 		db.Serial = data[0] >> 1
 		db.CRC = uint16(data[0]&B00000001)<<8 | uint16(data[1])
 		db.Data = make([]byte, db.Length)
-		copy(db.Data, data[2:db.Length])
-
-		//log.Debugf("data block serial: %#02x (%#07b), crc: %#02x (%#09b), length: %d, confirmed: %t:", db.Serial, db.Serial, db.CRC, db.CRC, db.Length, confirmed)
-		//log.Debug(hex.Dump(data[2 : 2+db.Length]))
+		copy(db.Data, data[2:2+db.Length])
 
 		for _, block := range db.Data {
 			crc9(&crc, block, 8)
@@ -56,7 +53,6 @@ func ParseDataBlock(data []byte, dataType uint8, confirmed bool) (*DataBlock, er
 		if crc != db.CRC {
 			return nil, fmt.Errorf("dmr: block CRC error (%#04x != %#04x)", crc, db.CRC)
 		}
-		log.Debugf("dmr: data block CRC passed %#04x", crc)
 	} else {
 		copy(db.Data, data[:db.Length])
 	}
@@ -239,8 +235,6 @@ func CombineDataBlocks(blocks []*DataBlock) (*DataFragment, error) {
 	if crc != f.CRC {
 		return nil, fmt.Errorf("dmr: fragment CRC error (%#08x != %#08x)", crc, f.CRC)
 	}
-	log.Debugf("dmr: data fragment CRC passed %#08x", crc)
-
 	return f, nil
 }
 
@@ -279,33 +273,6 @@ func ParseMessageData(data []byte, ddFormat uint8, nullTerminated bool) (string,
 }
 
 func init() {
-	/*
-		DDFormatBinary:         "binary",
-		DDFormatBCD:            "BCD",
-		DDFormat7BitChar:       "7-bit characters",
-		DDFormat8BitISO8859_1:  "8-bit ISO 8859-1",
-		DDFormat8BitISO8859_2:  "8-bit ISO 8859-2",
-		DDFormat8BitISO8859_3:  "8-bit ISO 8859-3",
-		DDFormat8BitISO8859_4:  "8-bit ISO 8859-4",
-		DDFormat8BitISO8859_5:  "8-bit ISO 8859-5",
-		DDFormat8BitISO8859_6:  "8-bit ISO 8859-6",
-		DDFormat8BitISO8859_7:  "8-bit ISO 8859-7",
-		DDFormat8BitISO8859_8:  "8-bit ISO 8859-8",
-		DDFormat8BitISO8859_9:  "8-bit ISO 8859-9",
-		DDFormat8BitISO8859_10: "8-bit ISO 8859-10",
-		DDFormat8BitISO8859_11: "8-bit ISO 8859-11",
-		DDFormat8BitISO8859_13: "8-bit ISO 8859-13",
-		DDFormat8BitISO8859_14: "8-bit ISO 8859-14",
-		DDFormat8BitISO8859_15: "8-bit ISO 8859-15",
-		DDFormat8BitISO8859_16: "8-bit ISO 8859-16",
-		DDFormatUTF8:           "UTF-8",
-		DDFormatUTF16:          "UTF-16",
-		DDFormatUTF16BE:        "UTF-16 big endian",
-		DDFormatUTF16LE:        "UTF-16 little endian",
-		DDFormatUTF32:          "UTF-32",
-		DDFormatUTF32BE:        "UTF-32 big endian",
-		DDFormatUTF32LE:        "UTF-32 little endian",
-	*/
 	encodingMap = map[uint8]encoding.Encoding{
 		DDFormatBinary:         binaryEncoding{},
 		DDFormat8BitISO8859_2:  charmap.ISO8859_2,