Add ip_version rule item

route/router_dns.go

@@ -5,6 +5,7 @@ import (
 	"net/netip"
 	"strings"
 
+	"github.com/sagernet/sing-box/adapter"
 	C "github.com/sagernet/sing-box/constant"
 	"github.com/sagernet/sing-box/log"
 	"github.com/sagernet/sing-dns"
@@ -18,6 +19,15 @@ func (r *Router) Exchange(ctx context.Context, message *dnsmessage.Message) (*dn
 	if len(message.Questions) > 0 {
 		r.dnsLogger.DebugContext(ctx, "exchange ", formatDNSQuestion(message.Questions[0]))
 	}
+	ctx, metadata := adapter.AppendContext(ctx)
+	if len(message.Questions) > 0 {
+		switch message.Questions[0].Type {
+		case dnsmessage.TypeA:
+			metadata.IPVersion = 4
+		case dnsmessage.TypeAAAA:
+			metadata.IPVersion = 6
+		}
+	}
 	ctx, transport := r.matchDNS(ctx)
 	ctx, cancel := context.WithTimeout(ctx, C.DNSTimeout)
 	defer cancel()

route/rule_dns.go

@@ -58,6 +58,16 @@ func NewDefaultDNSRule(router adapter.Router, logger log.ContextLogger, options
 		rule.items = append(rule.items, item)
 		rule.allItems = append(rule.allItems, item)
 	}
+	if options.IPVersion > 0 {
+		switch options.IPVersion {
+		case 4, 6:
+			item := NewIPVersionItem(options.IPVersion == 6)
+			rule.items = append(rule.items, item)
+			rule.allItems = append(rule.allItems, item)
+		default:
+			return nil, E.New("invalid ip version: ", options.IPVersion)
+		}
+	}
 	if options.Network != "" {
 		switch options.Network {
 		case N.NetworkTCP, N.NetworkUDP:

route/rule_ipversion.go

@@ -15,7 +15,8 @@ func NewIPVersionItem(isIPv6 bool) *IPVersionItem {
 }
 
 func (r *IPVersionItem) Match(metadata *adapter.InboundContext) bool {
-	return metadata.Destination.IsIP() && metadata.Destination.IsIPv6() == r.isIPv6
+	return metadata.IPVersion != 0 && metadata.IPVersion == 6 == r.isIPv6 ||
+		metadata.Destination.IsIP() && metadata.Destination.IsIPv6() == r.isIPv6
 }
 
 func (r *IPVersionItem) String() string {