Add resolver for outbound dialer

common/dialer/override.go

@@ -0,0 +1,70 @@
+package dialer
+
+import (
+	"context"
+	"crypto/tls"
+	"net"
+
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+	"github.com/sagernet/sing/common/uot"
+
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/option"
+)
+
+var _ N.Dialer = (*OverrideDialer)(nil)
+
+type OverrideDialer struct {
+	upstream   N.Dialer
+	tlsEnabled bool
+	tlsConfig  tls.Config
+	uotEnabled bool
+}
+
+func NewOverride(upstream N.Dialer, options option.OverrideStreamOptions) N.Dialer {
+	return &OverrideDialer{
+		upstream,
+		options.TLS,
+		tls.Config{
+			ServerName:         options.TLSServerName,
+			InsecureSkipVerify: options.TLSInsecure,
+		},
+		options.UDPOverTCP,
+	}
+}
+
+func (d *OverrideDialer) DialContext(ctx context.Context, network string, destination M.Socksaddr) (net.Conn, error) {
+	switch network {
+	case C.NetworkTCP:
+		conn, err := d.upstream.DialContext(ctx, C.NetworkTCP, destination)
+		if err != nil {
+			return nil, err
+		}
+		return tls.Client(conn, &d.tlsConfig), nil
+	case C.NetworkUDP:
+		if d.uotEnabled {
+			tcpConn, err := d.upstream.DialContext(ctx, C.NetworkTCP, destination)
+			if err != nil {
+				return nil, err
+			}
+			return uot.NewClientConn(tcpConn), nil
+		}
+	}
+	return d.upstream.DialContext(ctx, network, destination)
+}
+
+func (d *OverrideDialer) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
+	if d.uotEnabled {
+		tcpConn, err := d.upstream.DialContext(ctx, C.NetworkTCP, destination)
+		if err != nil {
+			return nil, err
+		}
+		return uot.NewClientConn(tcpConn), nil
+	}
+	return d.upstream.ListenPacket(ctx, destination)
+}
+
+func (d *OverrideDialer) Upstream() any {
+	return d.upstream
+}