Implement route rules

adapter/route/rule_ipversion.go

@@ -0,0 +1,29 @@
+package route
+
+import (
+	"github.com/sagernet/sing-box/adapter"
+)
+
+var _ RuleItem = (*IPVersionItem)(nil)
+
+type IPVersionItem struct {
+	isIPv6 bool
+}
+
+func NewIPVersionItem(isIPv6 bool) *IPVersionItem {
+	return &IPVersionItem{isIPv6}
+}
+
+func (r *IPVersionItem) Match(metadata *adapter.InboundContext) bool {
+	return metadata.Destination.IsIP() && metadata.Destination.Family().IsIPv6() == r.isIPv6
+}
+
+func (r *IPVersionItem) String() string {
+	var versionStr string
+	if r.isIPv6 {
+		versionStr = "6"
+	} else {
+		versionStr = "4"
+	}
+	return "ip_version=" + versionStr
+}