Crazy sekai overturns the small pond

route/rule/rule_item_ip_is_private.go

@@ -0,0 +1,46 @@
+package rule
+
+import (
+	"net/netip"
+
+	"github.com/sagernet/sing-box/adapter"
+	N "github.com/sagernet/sing/common/network"
+)
+
+var _ RuleItem = (*IPIsPrivateItem)(nil)
+
+type IPIsPrivateItem struct {
+	isSource bool
+}
+
+func NewIPIsPrivateItem(isSource bool) *IPIsPrivateItem {
+	return &IPIsPrivateItem{isSource}
+}
+
+func (r *IPIsPrivateItem) Match(metadata *adapter.InboundContext) bool {
+	var destination netip.Addr
+	if r.isSource {
+		destination = metadata.Source.Addr
+	} else {
+		destination = metadata.Destination.Addr
+	}
+	if destination.IsValid() {
+		return !N.IsPublicAddr(destination)
+	}
+	if !r.isSource {
+		for _, destinationAddress := range metadata.DestinationAddresses {
+			if !N.IsPublicAddr(destinationAddress) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func (r *IPIsPrivateItem) String() string {
+	if r.isSource {
+		return "source_ip_is_private=true"
+	} else {
+		return "ip_is_private=true"
+	}
+}