add initial address definition

pkg/definitions/address.go

@@ -0,0 +1,52 @@
+package definitions
+
+import (
+	"encoding/json"
+	"net/netip"
+
+	"go4.org/netipx"
+)
+
+type Address struct {
+	Type     AddressType     `json:"type"`
+	Comment  string          `json:"comment,omitempty"`
+	Host     *netip.Addr     `json:"host,omitempty"`
+	Range    *netipx.IPRange `json:"range,omitempty"`
+	Children *[]string       `json:"children,omitempty"`
+}
+
+type AddressType int
+
+const (
+	Host AddressType = iota
+	Range
+	Network
+	Group
+)
+
+func (t AddressType) String() string {
+	return [...]string{"host", "range", "network", "group"}[t]
+}
+
+func (t *AddressType) FromString(input string) AddressType {
+	return map[string]AddressType{
+		"host":    Host,
+		"range":   Range,
+		"network": Network,
+		"group":   Group,
+	}[input]
+}
+
+func (t AddressType) MarshalJSON() ([]byte, error) {
+	return json.Marshal(t.String())
+}
+
+func (t *AddressType) UnmarshalJSON(b []byte) error {
+	var s string
+	err := json.Unmarshal(b, &s)
+	if err != nil {
+		return err
+	}
+	*t = t.FromString(s)
+	return nil
+}