Go code!

go/pkg/zerotier/mac.go

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c)2019 ZeroTier, Inc.
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file in the project's root directory.
+ *
+ * Change Date: 2023-01-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2.0 of the Apache License.
+ */
+/****/
+
+package zerotier
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// MAC represents an Ethernet hardware address
+type MAC uint64
+
+// NewMACFromString decodes a MAC address in canonical colon-separated hex format
+func NewMACFromString(s string) (MAC, error) {
+	ss := strings.Split(s, ":")
+	if len(ss) != 6 {
+		return MAC(0), ErrInvalidMACAddress
+	}
+	var m uint64
+	for i := 0; i < 6; i++ {
+		m <<= 8
+		c, _ := strconv.ParseUint(ss[i], 16, 64)
+		if c > 0xff {
+			return MAC(0), ErrInvalidMACAddress
+		}
+		m |= (c & 0xff)
+	}
+	return MAC(m), nil
+}
+
+// String returns this MAC address in canonical human-readable form
+func (m MAC) String() string {
+	return fmt.Sprintf("%.2x:%.2x:%.2x:%.2x:%.2x:%.2x", (m>>40)&0xff, (m>>32)&0xff, (m>>24)&0xff, (m>>16)&0xff, (m>>8)&0xff, m&0xff)
+}
+
+// MarshalJSON marshals this MAC as a string
+func (m MAC) MarshalJSON() ([]byte, error) {
+	return []byte(m.String()), nil
+}
+
+// UnmarshalJSON unmarshals this MAC from a string
+func (m *MAC) UnmarshalJSON(j []byte) error {
+	var s string
+	err := json.Unmarshal(j, &s)
+	if err != nil {
+		return err
+	}
+	*m, err = NewMACFromString(s)
+	return err
+}