Inbound rule support

option/network.go

@@ -0,0 +1,35 @@
+package option
+
+import (
+	"encoding/json"
+	"strings"
+
+	C "github.com/sagernet/sing-box/constant"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+type NetworkList []string
+
+func (v *NetworkList) UnmarshalJSON(data []byte) error {
+	var networkList string
+	err := json.Unmarshal(data, &networkList)
+	if err != nil {
+		return err
+	}
+	for _, networkName := range strings.Split(networkList, ",") {
+		switch networkName {
+		case "tcp", "udp":
+			*v = append(*v, networkName)
+		default:
+			return E.New("unknown network: " + networkName)
+		}
+	}
+	return nil
+}
+
+func (v *NetworkList) Build() []string {
+	if len(*v) == 0 {
+		return []string{C.NetworkTCP, C.NetworkUDP}
+	}
+	return *v
+}