Add support for ech retry configs

common/tls/client.go

@@ -2,10 +2,11 @@ package tls
 
 import (
 	"context"
+	"crypto/tls"
+	"errors"
 	"net"
 	"os"
 
-	"github.com/sagernet/sing-box/adapter"
 	"github.com/sagernet/sing-box/common/badtls"
 	C "github.com/sagernet/sing-box/constant"
 	"github.com/sagernet/sing-box/option"
@@ -14,7 +15,7 @@ import (
 	aTLS "github.com/sagernet/sing/common/tls"
 )
 
-func NewDialerFromOptions(ctx context.Context, router adapter.Router, dialer N.Dialer, serverAddress string, options option.OutboundTLSOptions) (N.Dialer, error) {
+func NewDialerFromOptions(ctx context.Context, dialer N.Dialer, serverAddress string, options option.OutboundTLSOptions) (N.Dialer, error) {
 	if !options.Enabled {
 		return dialer, nil
 	}
@@ -53,26 +54,57 @@ func ClientHandshake(ctx context.Context, conn net.Conn, config Config) (Conn, e
 	return tlsConn, nil
 }
 
-type Dialer struct {
+type Dialer interface {
+	N.Dialer
+	DialTLSContext(ctx context.Context, destination M.Socksaddr) (Conn, error)
+}
+
+type defaultDialer struct {
 	dialer N.Dialer
 	config Config
 }
 
-func NewDialer(dialer N.Dialer, config Config) N.Dialer {
-	return &Dialer{dialer, config}
+func NewDialer(dialer N.Dialer, config Config) Dialer {
+	return &defaultDialer{dialer, config}
 }
 
-func (d *Dialer) DialContext(ctx context.Context, network string, destination M.Socksaddr) (net.Conn, error) {
-	if network != N.NetworkTCP {
+func (d *defaultDialer) DialContext(ctx context.Context, network string, destination M.Socksaddr) (net.Conn, error) {
+	if N.NetworkName(network) != N.NetworkTCP {
 		return nil, os.ErrInvalid
 	}
-	conn, err := d.dialer.DialContext(ctx, network, destination)
+	return d.DialTLSContext(ctx, destination)
+}
+
+func (d *defaultDialer) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
+	return nil, os.ErrInvalid
+}
+
+func (d *defaultDialer) DialTLSContext(ctx context.Context, destination M.Socksaddr) (Conn, error) {
+	return d.dialContext(ctx, destination, true)
+}
+
+func (d *defaultDialer) dialContext(ctx context.Context, destination M.Socksaddr, echRetry bool) (Conn, error) {
+	conn, err := d.dialer.DialContext(ctx, N.NetworkTCP, destination)
 	if err != nil {
 		return nil, err
 	}
-	return ClientHandshake(ctx, conn, d.config)
+	tlsConn, err := ClientHandshake(ctx, conn, d.config)
+	if err == nil {
+		return tlsConn, nil
+	}
+	conn.Close()
+	if echRetry {
+		var echErr *tls.ECHRejectionError
+		if errors.As(err, &echErr) && len(echErr.RetryConfigList) > 0 {
+			if echConfig, isECH := d.config.(ECHCapableConfig); isECH {
+				echConfig.SetECHConfigList(echErr.RetryConfigList)
+			}
+		}
+		return d.dialContext(ctx, destination, false)
+	}
+	return nil, err
 }
 
-func (d *Dialer) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
-	return nil, os.ErrInvalid
+func (d *defaultDialer) Upstream() any {
+	return d.dialer
 }