feat(dnstt): integrate hmrd_multi_resolver_dns smart pool inside dnstt

go.mod

@@ -1,6 +1,6 @@
 module github.com/sagernet/sing-box
 
-go 1.24.7
+go 1.25.6
 
 require github.com/amnezia-vpn/amneziawg-go v0.2.16
 
@@ -145,6 +145,7 @@ require (
 	github.com/grafov/m3u8 v0.0.0-20171211212457-6ab8f28ed427 // indirect
 	github.com/hashicorp/yamux v0.1.2 // indirect
 	github.com/hdevalence/ed25519consensus v0.2.0 // indirect
+	github.com/hiddify/hmrd_multi_resolver_dns v0.0.0-20260429114007-8d809dc33d0e
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86 // indirect
 	github.com/kamstrup/intmap v0.5.2 // indirect

go.sum

@@ -216,6 +216,8 @@ github.com/hashicorp/yamux v0.1.2 h1:XtB8kyFOyHXYVFnwT5C3+Bdo8gArse7j2AQ0DA0Uey8
 github.com/hashicorp/yamux v0.1.2/go.mod h1:C+zze2n6e/7wshOZep2A70/aQU6QBRWJO/G6FT1wIns=
 github.com/hdevalence/ed25519consensus v0.2.0 h1:37ICyZqdyj0lAZ8P4D1d1id3HqbbG1N3iBb1Tb4rdcU=
 github.com/hdevalence/ed25519consensus v0.2.0/go.mod h1:w3BHWjwJbFU29IRHL1Iqkw3sus+7FctEyM4RqDxYNzo=
+github.com/hiddify/hmrd_multi_resolver_dns v0.0.0-20260429114007-8d809dc33d0e h1:GsHpSccRtSFe1l3hq0WtBjqsKjJdU+an2D+uCsXm+xk=
+github.com/hiddify/hmrd_multi_resolver_dns v0.0.0-20260429114007-8d809dc33d0e/go.mod h1:7u9Ece+I3gvMFzcpqhROWaykNUyoE21g/fYQMBasAWY=
 github.com/hiddify/vaydns v0.0.0-20260401180616-890dc987a6a9 h1:KXnaABX8hHmkcL0jbL769hEIGI5+z/DajCrlO+Bkzcc=
 github.com/hiddify/vaydns v0.0.0-20260401180616-890dc987a6a9/go.mod h1:+8kEfQsZJn7/4aIppVekrSuqhrKjGBIgnacTJkdAlS8=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=

option/dnstt.go

@@ -40,4 +40,10 @@ type DnsttOptions struct {
 	UdpSharedSocket bool                `json:"udp-shared-socket,omitempty"`
 	UdpTimeout      *badoption.Duration `json:"udp-timeout,omitempty"`
 	UdpWorkers      *int                `json:"udp-workers,omitempty"`
+
+	// SmartPool routes every resolver registered via the dnstt outbound's
+	// addResolver flow through an internal hmrd_multi_resolver_dns pool
+	// (deadline-aware failover, AIMD throttling, recovery probing) instead
+	// of using each resolver as its own tunnel.
+	SmartPool bool `json:"smart_pool,omitempty"`
 }

protocol/hiddify/dnstt/dnstt_func.go

@@ -13,18 +13,39 @@ import (
 
 func (c *Outbound) addResolver(resolver dnstt.Resolver) {
 	c.mu.Lock()
-	// for i := 0; i < c.options.TunnelPerResolver; i++ {
-	c.resolvers = append(c.resolvers, resolver)
-	c.tunnels = append(c.tunnels, nil)
-	c.mutlitunnel = nil
-	// }
+	if c.mdMgr != nil {
+		// Smart pool mode: register the resolver as a multidns upstream.
+		// c.resolvers stays at the single virtual resolver set up in
+		// NewOutbound, so the existing tunnel keeps running — the pool
+		// rotates upstreams behind it. No need to invalidate
+		// c.mutlitunnel here (unlike the legacy path, which has to
+		// rebuild the tunnel when its resolver list changes).
+		_, _ = c.mdMgr.AddResolverURL(resolverURL(resolver))
+	} else {
+		// for i := 0; i < c.options.TunnelPerResolver; i++ {
+		c.resolvers = append(c.resolvers, resolver)
+		c.tunnels = append(c.tunnels, nil)
+		// }
+		c.mutlitunnel = nil
+	}
 	c.mu.Unlock()
 	if !c.IsReady() {
 		c.started = 1
 		c.logger.InfoContext(c.ctx, "initial resolver ", resolver.ResolverAddr)
 		monitoring.Get(c.ctx).TestNow(c.Tag())
 	}
+}
 
+// resolverURL renders a dnstt.Resolver as the URL form multidns parses.
+// UDP resolvers are bare host:port (multidns defaults to UDP/53); DoT gets
+// the "dot://" prefix; DoH is already a full https:// URL.
+func resolverURL(r dnstt.Resolver) string {
+	switch r.ResolverType {
+	case dnstt.ResolverTypeDOT:
+		return "dot://" + r.ResolverAddr
+	default:
+		return r.ResolverAddr
+	}
 }
 
 func (c *Outbound) openStreamImp(ctx context.Context) (net.Conn, error) {

protocol/hiddify/dnstt/outbound.go

@@ -7,6 +7,7 @@ import (
 	"sync"
 	"time"
 
+	multidns "github.com/hiddify/hmrd_multi_resolver_dns"
 	dnstt "github.com/net2share/vaydns/client"
 	"github.com/sagernet/sing-box/adapter"
 	"github.com/sagernet/sing-box/adapter/outbound"
@@ -46,6 +47,8 @@ type Outbound struct {
 	resolve            bool
 	tunnel_index       int
 
+	mdMgr *multidns.Manager // smart pool, set when options.SmartPool
+
 	options option.DnsttOptions
 }
 
@@ -110,6 +113,17 @@ func NewOutbound(ctx context.Context, router adapter.Router, logger log.ContextL
 		options: options,
 	}
 
+	if options.SmartPool {
+		mgr, addr, err := multidns.StartLocal(multidns.Options{})
+		if err != nil {
+			return nil, err
+		}
+		out.mdMgr = mgr
+		out.resolvers = []dnstt.Resolver{{ResolverType: dnstt.ResolverTypeUDP, ResolverAddr: addr}}
+		out.tunnels = []*dnstt.Tunnel{nil}
+		logger.InfoContext(ctx, "dnstt smart_pool listening on ", addr)
+	}
+
 	return out, nil
 
 }
@@ -158,5 +172,8 @@ func (c *Outbound) Close() error {
 			t.Close()
 		}
 	}
+	if c.mdMgr != nil {
+		_ = c.mdMgr.Close()
+	}
 	return nil
 }