package inbound import ( "context" "net" "net/netip" "github.com/sagernet/sing-box/adapter" "github.com/sagernet/sing-box/common/redir" C "github.com/sagernet/sing-box/constant" "github.com/sagernet/sing-box/log" "github.com/sagernet/sing-box/option" "github.com/sagernet/sing/common" "github.com/sagernet/sing/common/buf" E "github.com/sagernet/sing/common/exceptions" M "github.com/sagernet/sing/common/metadata" N "github.com/sagernet/sing/common/network" "github.com/sagernet/sing/common/udpnat" ) type TProxy struct { myInboundAdapter udpNat *udpnat.Service[netip.AddrPort] } func NewTProxy(ctx context.Context, router adapter.Router, logger log.ContextLogger, tag string, options option.TProxyInboundOptions) *TProxy { tproxy := &TProxy{ myInboundAdapter: myInboundAdapter{ protocol: C.TypeTProxy, network: options.Network.Build(), ctx: ctx, router: router, logger: logger, tag: tag, listenOptions: options.ListenOptions, }, } var udpTimeout int64 if options.UDPTimeout != 0 { udpTimeout = options.UDPTimeout } else { udpTimeout = int64(C.UDPTimeout.Seconds()) } tproxy.connHandler = tproxy tproxy.oobPacketHandler = tproxy tproxy.udpNat = udpnat.New[netip.AddrPort](udpTimeout, tproxy.upstreamContextHandler()) tproxy.packetUpstream = tproxy.udpNat return tproxy } func (t *TProxy) Start() error { err := t.myInboundAdapter.Start() if err != nil { return err } if t.tcpListener != nil { tcpFd, err := common.GetFileDescriptor(t.tcpListener) if err != nil { return err } err = redir.TProxy(tcpFd, M.SocksaddrFromNet(t.tcpListener.Addr()).Addr.Is6()) if err != nil { return E.Cause(err, "configure tproxy TCP listener") } } if t.udpConn != nil { udpFd, err := common.GetFileDescriptor(t.udpConn) if err != nil { return err } err = redir.TProxy(udpFd, M.SocksaddrFromNet(t.udpConn.LocalAddr()).Addr.Is6()) if err != nil { return E.Cause(err, "configure tproxy UDP listener") } } return nil } func (t *TProxy) NewConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error { metadata.Destination = M.SocksaddrFromNet(conn.LocalAddr()) return t.newConnection(ctx, conn, metadata) } func (t *TProxy) NewPacket(ctx context.Context, conn N.PacketConn, buffer *buf.Buffer, oob []byte, metadata adapter.InboundContext) error { destination, err := redir.GetOriginalDestinationFromOOB(oob) if err != nil { return E.Cause(err, "get tproxy destination") } metadata.Destination = M.SocksaddrFromNetIP(destination) t.udpNat.NewContextPacket(ctx, metadata.Source.AddrPort(), buffer, adapter.UpstreamMetadata(metadata), func(natConn N.PacketConn) (context.Context, N.PacketWriter) { return adapter.WithContext(log.ContextWithNewID(ctx), &metadata), &tproxyPacketWriter{natConn} }) return nil } type tproxyPacketWriter struct { source N.PacketConn } func (w *tproxyPacketWriter) WritePacket(buffer *buf.Buffer, destination M.Socksaddr) error { defer buffer.Release() udpConn, err := redir.DialUDP(destination.UDPAddr(), M.SocksaddrFromNet(w.source.LocalAddr()).UDPAddr()) if err != nil { return E.Cause(err, "tproxy udp write back") } defer udpConn.Close() return common.Error(udpConn.Write(buffer.Bytes())) }