package inbound import ( "context" "crypto/tls" "net" "os" "github.com/sagernet/sing-box/adapter" C "github.com/sagernet/sing-box/constant" "github.com/sagernet/sing-box/log" "github.com/sagernet/sing-box/option" "github.com/sagernet/sing-box/transport/v2ray" "github.com/sagernet/sing/common" "github.com/sagernet/sing/common/auth" E "github.com/sagernet/sing/common/exceptions" F "github.com/sagernet/sing/common/format" M "github.com/sagernet/sing/common/metadata" N "github.com/sagernet/sing/common/network" "github.com/sagernet/sing/protocol/trojan" ) var _ adapter.Inbound = (*Trojan)(nil) type Trojan struct { myInboundAdapter service *trojan.Service[int] users []option.TrojanUser tlsConfig *TLSConfig fallbackAddr M.Socksaddr fallbackAddrTLSNextProto map[string]M.Socksaddr transport adapter.V2RayServerTransport } func NewTrojan(ctx context.Context, router adapter.Router, logger log.ContextLogger, tag string, options option.TrojanInboundOptions) (*Trojan, error) { inbound := &Trojan{ myInboundAdapter: myInboundAdapter{ protocol: C.TypeTrojan, network: []string{N.NetworkTCP}, ctx: ctx, router: router, logger: logger, tag: tag, listenOptions: options.ListenOptions, }, users: options.Users, } if options.TLS != nil { tlsConfig, err := NewTLSConfig(ctx, logger, common.PtrValueOrDefault(options.TLS)) if err != nil { return nil, err } inbound.tlsConfig = tlsConfig } var fallbackHandler N.TCPConnectionHandler if options.Fallback != nil && options.Fallback.Server != "" || len(options.FallbackForALPN) > 0 { if options.Fallback != nil && options.Fallback.Server != "" { inbound.fallbackAddr = options.Fallback.Build() if !inbound.fallbackAddr.IsValid() { return nil, E.New("invalid fallback address: ", inbound.fallbackAddr) } } if len(options.FallbackForALPN) > 0 { if inbound.tlsConfig == nil { return nil, E.New("fallback for ALPN is not supported without TLS") } fallbackAddrNextProto := make(map[string]M.Socksaddr) for nextProto, destination := range options.FallbackForALPN { fallbackAddr := destination.Build() if !fallbackAddr.IsValid() { return nil, E.New("invalid fallback address for ALPN ", nextProto, ": ", fallbackAddr) } fallbackAddrNextProto[nextProto] = fallbackAddr } inbound.fallbackAddrTLSNextProto = fallbackAddrNextProto } fallbackHandler = adapter.NewUpstreamContextHandler(inbound.fallbackConnection, nil, nil) } service := trojan.NewService[int](adapter.NewUpstreamContextHandler(inbound.newConnection, inbound.newPacketConnection, inbound), fallbackHandler) err := service.UpdateUsers(common.MapIndexed(options.Users, func(index int, it option.TrojanUser) int { return index }), common.Map(options.Users, func(it option.TrojanUser) string { return it.Password })) if err != nil { return nil, err } if options.Transport != nil { var tlsConfig *tls.Config if inbound.tlsConfig != nil { tlsConfig = inbound.tlsConfig.Config() } inbound.transport, err = v2ray.NewServerTransport(ctx, common.PtrValueOrDefault(options.Transport), tlsConfig, adapter.NewUpstreamHandler(adapter.InboundContext{}, inbound.newTransportConnection, nil, nil), inbound) if err != nil { return nil, E.Cause(err, "create server transport: ", options.Transport.Type) } } inbound.service = service inbound.connHandler = inbound return inbound, nil } func (h *Trojan) Start() error { if h.tlsConfig != nil { err := h.tlsConfig.Start() if err != nil { return E.Cause(err, "create TLS config") } } if h.transport == nil { return h.myInboundAdapter.Start() } if common.Contains(h.transport.Network(), N.NetworkTCP) { tcpListener, err := h.myInboundAdapter.ListenTCP() if err != nil { return err } go func() { sErr := h.transport.Serve(tcpListener) if sErr != nil && !E.IsClosed(sErr) { h.logger.Error("transport serve error: ", sErr) } }() } if common.Contains(h.transport.Network(), N.NetworkUDP) { udpConn, err := h.myInboundAdapter.ListenUDP() if err != nil { return err } go func() { sErr := h.transport.ServePacket(udpConn) if sErr != nil && !E.IsClosed(sErr) { h.logger.Error("transport serve error: ", sErr) } }() } return nil } func (h *Trojan) Close() error { return common.Close( &h.myInboundAdapter, common.PtrOrNil(h.tlsConfig), h.transport, ) } func (h *Trojan) newTransportConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error { h.injectTCP(conn) return nil } func (h *Trojan) NewConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error { if h.tlsConfig != nil && h.transport == nil { conn = tls.Server(conn, h.tlsConfig.Config()) } return h.service.NewConnection(adapter.WithContext(log.ContextWithNewID(ctx), &metadata), conn, adapter.UpstreamMetadata(metadata)) } func (h *Trojan) newConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error { userIndex, loaded := auth.UserFromContext[int](ctx) if !loaded { return os.ErrInvalid } user := h.users[userIndex].Name if user == "" { user = F.ToString(userIndex) } else { metadata.User = user } h.logger.InfoContext(ctx, "[", user, "] inbound connection to ", metadata.Destination) return h.router.RouteConnection(ctx, conn, metadata) } func (h *Trojan) fallbackConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error { var fallbackAddr M.Socksaddr if len(h.fallbackAddrTLSNextProto) > 0 { if tlsConn, loaded := common.Cast[*tls.Conn](conn); loaded { connectionState := tlsConn.ConnectionState() if connectionState.NegotiatedProtocol != "" { if fallbackAddr, loaded = h.fallbackAddrTLSNextProto[connectionState.NegotiatedProtocol]; !loaded { return E.New("fallback disabled for ALPN: ", connectionState.NegotiatedProtocol) } } } } if !fallbackAddr.IsValid() { fallbackAddr = h.fallbackAddr } h.logger.InfoContext(ctx, "fallback connection to ", fallbackAddr) metadata.Destination = fallbackAddr return h.router.RouteConnection(ctx, conn, metadata) } func (h *Trojan) newPacketConnection(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext) error { userIndex, loaded := auth.UserFromContext[int](ctx) if !loaded { return os.ErrInvalid } user := h.users[userIndex].Name if user == "" { user = F.ToString(userIndex) } else { metadata.User = user } h.logger.InfoContext(ctx, "[", user, "] inbound packet connection to ", metadata.Destination) return h.router.RoutePacketConnection(ctx, conn, metadata) }