Fix resolve dialer

common/dialer/dialer.go

@@ -29,7 +29,12 @@ func New(router adapter.Router, options option.DialerOptions) (N.Dialer, error)
 	}
 	domainStrategy := dns.DomainStrategy(options.DomainStrategy)
 	if domainStrategy != dns.DomainStrategyAsIS || options.Detour == "" {
-		dialer = NewResolveDialer(router, dialer, domainStrategy, time.Duration(options.FallbackDelay))
+		dialer = NewResolveDialer(
+			router,
+			dialer,
+			options.Detour == "" && !options.TCPFastOpen,
+			domainStrategy,
+			time.Duration(options.FallbackDelay))
 	}
 	return dialer, nil
 }

common/dialer/resolve.go

@@ -16,14 +16,16 @@ import (
 
 type ResolveDialer struct {
 	dialer        N.Dialer
+	parallel      bool
 	router        adapter.Router
 	strategy      dns.DomainStrategy
 	fallbackDelay time.Duration
 }
 
-func NewResolveDialer(router adapter.Router, dialer N.Dialer, strategy dns.DomainStrategy, fallbackDelay time.Duration) *ResolveDialer {
+func NewResolveDialer(router adapter.Router, dialer N.Dialer, parallel bool, strategy dns.DomainStrategy, fallbackDelay time.Duration) *ResolveDialer {
 	return &ResolveDialer{
 		dialer,
+		parallel,
 		router,
 		strategy,
 		fallbackDelay,
@@ -48,7 +50,11 @@ func (d *ResolveDialer) DialContext(ctx context.Context, network string, destina
 	if err != nil {
 		return nil, err
 	}
-	return N.DialParallel(ctx, d.dialer, network, destination, addresses, d.strategy == dns.DomainStrategyPreferIPv6, d.fallbackDelay)
+	if d.parallel {
+		return N.DialParallel(ctx, d.dialer, network, destination, addresses, d.strategy == dns.DomainStrategyPreferIPv6, d.fallbackDelay)
+	} else {
+		return N.DialSerial(ctx, d.dialer, network, destination, addresses)
+	}
 }
 
 func (d *ResolveDialer) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {

go.mod

@@ -30,7 +30,7 @@ require (
 	github.com/sagernet/sing-shadowsocks v0.2.5-0.20230907005610-126234728ca0
 	github.com/sagernet/sing-shadowsocks2 v0.1.4-0.20230907005906-5d2917b29248
 	github.com/sagernet/sing-shadowtls v0.1.4
-	github.com/sagernet/sing-tun v0.1.12-0.20230925100705-ef831c3485cf
+	github.com/sagernet/sing-tun v0.1.12-0.20230926093914-0d0ebad6cfa5
 	github.com/sagernet/sing-vmess v0.1.8-0.20230907010359-161fb0ac716b
 	github.com/sagernet/smux v0.0.0-20230312102458-337ec2a5af37
 	github.com/sagernet/tfo-go v0.0.0-20230816093905-5a5c285d44a6

go.sum

@@ -122,8 +122,8 @@ github.com/sagernet/sing-shadowsocks2 v0.1.4-0.20230907005906-5d2917b29248 h1:JT
 github.com/sagernet/sing-shadowsocks2 v0.1.4-0.20230907005906-5d2917b29248/go.mod h1:DOhJc/cLeqRv0wuePrQso+iUmDxOnWF4eT/oMcRzYFw=
 github.com/sagernet/sing-shadowtls v0.1.4 h1:aTgBSJEgnumzFenPvc+kbD9/W0PywzWevnVpEx6Tw3k=
 github.com/sagernet/sing-shadowtls v0.1.4/go.mod h1:F8NBgsY5YN2beQavdgdm1DPlhaKQlaL6lpDdcBglGK4=
-github.com/sagernet/sing-tun v0.1.12-0.20230925100705-ef831c3485cf h1:7migLbdEzt57BCCzBxpTbmyszhjsoebMxKyT24Wu0Y8=
+github.com/sagernet/sing-tun v0.1.12-0.20230926093914-0d0ebad6cfa5 h1:2KpqI83FequwVysUX6SkUCFvR7pmoGzxei/QD0p682M=
-github.com/sagernet/sing-tun v0.1.12-0.20230925100705-ef831c3485cf/go.mod h1:+YImslQMLgMQcVgZZ9IK4ue1o/605VSU90amHUcp4hA=
+github.com/sagernet/sing-tun v0.1.12-0.20230926093914-0d0ebad6cfa5/go.mod h1:+YImslQMLgMQcVgZZ9IK4ue1o/605VSU90amHUcp4hA=
 github.com/sagernet/sing-vmess v0.1.8-0.20230907010359-161fb0ac716b h1:2ezfJtH5JosiEwJhVa+rimQ6ps/t2+7h+mOzMoiaZnA=
 github.com/sagernet/sing-vmess v0.1.8-0.20230907010359-161fb0ac716b/go.mod h1:1qkC1L1T2sxnS/NuO6HU72S8TkltV+EXoKGR29m/Yss=
 github.com/sagernet/smux v0.0.0-20230312102458-337ec2a5af37 h1:HuE6xSwco/Xed8ajZ+coeYLmioq0Qp1/Z2zczFaV8as=

test/go.mod

@@ -73,7 +73,7 @@ require (
 	github.com/sagernet/sing-dns v0.1.9-0.20230925101650-9cc09becd01e // indirect
 	github.com/sagernet/sing-mux v0.1.3-0.20230907005326-7befbadbf314 // indirect
 	github.com/sagernet/sing-shadowtls v0.1.4 // indirect
-	github.com/sagernet/sing-tun v0.1.12-0.20230925100705-ef831c3485cf // indirect
+	github.com/sagernet/sing-tun v0.1.12-0.20230926093914-0d0ebad6cfa5 // indirect
 	github.com/sagernet/sing-vmess v0.1.8-0.20230907010359-161fb0ac716b // indirect
 	github.com/sagernet/smux v0.0.0-20230312102458-337ec2a5af37 // indirect
 	github.com/sagernet/tfo-go v0.0.0-20230816093905-5a5c285d44a6 // indirect

test/go.sum

@@ -139,6 +139,7 @@ github.com/sagernet/sing-shadowtls v0.1.4 h1:aTgBSJEgnumzFenPvc+kbD9/W0PywzWevnV
 github.com/sagernet/sing-shadowtls v0.1.4/go.mod h1:F8NBgsY5YN2beQavdgdm1DPlhaKQlaL6lpDdcBglGK4=
 github.com/sagernet/sing-tun v0.1.12-0.20230925100705-ef831c3485cf h1:7migLbdEzt57BCCzBxpTbmyszhjsoebMxKyT24Wu0Y8=
 github.com/sagernet/sing-tun v0.1.12-0.20230925100705-ef831c3485cf/go.mod h1:+YImslQMLgMQcVgZZ9IK4ue1o/605VSU90amHUcp4hA=
+github.com/sagernet/sing-tun v0.1.12-0.20230926093914-0d0ebad6cfa5/go.mod h1:+YImslQMLgMQcVgZZ9IK4ue1o/605VSU90amHUcp4hA=
 github.com/sagernet/sing-vmess v0.1.8-0.20230907010359-161fb0ac716b h1:2ezfJtH5JosiEwJhVa+rimQ6ps/t2+7h+mOzMoiaZnA=
 github.com/sagernet/sing-vmess v0.1.8-0.20230907010359-161fb0ac716b/go.mod h1:1qkC1L1T2sxnS/NuO6HU72S8TkltV+EXoKGR29m/Yss=
 github.com/sagernet/smux v0.0.0-20230312102458-337ec2a5af37 h1:HuE6xSwco/Xed8ajZ+coeYLmioq0Qp1/Z2zczFaV8as=