package inbound import ( "context" "net" "net/netip" "os" "sync" "time" "github.com/sagernet/sing-box/adapter" "github.com/sagernet/sing-box/common/settings" C "github.com/sagernet/sing-box/constant" "github.com/sagernet/sing-box/log" "github.com/sagernet/sing-box/option" "github.com/sagernet/sing-dns" "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/database64128/tfo-go" ) var _ adapter.Inbound = (*myInboundAdapter)(nil) type myInboundAdapter struct { protocol string network []string ctx context.Context router adapter.Router logger log.ContextLogger tag string listenOptions option.ListenOptions connHandler adapter.ConnectionHandler packetHandler adapter.PacketHandler oobPacketHandler adapter.OOBPacketHandler packetUpstream any // http mixed setSystemProxy bool // internal tcpListener *net.TCPListener udpConn *net.UDPConn packetForce6 bool packetAccess sync.RWMutex packetOutboundClosed chan struct{} packetOutbound chan *myInboundPacket } func (a *myInboundAdapter) Type() string { return a.protocol } func (a *myInboundAdapter) Tag() string { return a.tag } func (a *myInboundAdapter) Start() error { bindAddr := M.SocksaddrFrom(netip.Addr(a.listenOptions.Listen), a.listenOptions.ListenPort) if common.Contains(a.network, C.NetworkTCP) { var tcpListener *net.TCPListener var err error if !a.listenOptions.TCPFastOpen { tcpListener, err = net.ListenTCP(M.NetworkFromNetAddr(C.NetworkTCP, bindAddr.Addr), bindAddr.TCPAddr()) } else { tcpListener, err = tfo.ListenTCP(M.NetworkFromNetAddr(C.NetworkTCP, bindAddr.Addr), bindAddr.TCPAddr()) } if err != nil { return err } a.tcpListener = tcpListener go a.loopTCPIn() a.logger.Info("tcp server started at ", tcpListener.Addr()) } if common.Contains(a.network, C.NetworkUDP) { udpConn, err := net.ListenUDP(M.NetworkFromNetAddr(C.NetworkUDP, bindAddr.Addr), bindAddr.UDPAddr()) if err != nil { return err } a.udpConn = udpConn a.packetForce6 = M.SocksaddrFromNet(udpConn.LocalAddr()).Addr.Is6() a.packetOutboundClosed = make(chan struct{}) a.packetOutbound = make(chan *myInboundPacket) if a.oobPacketHandler != nil { if _, threadUnsafeHandler := common.Cast[N.ThreadUnsafeWriter](a.packetUpstream); !threadUnsafeHandler { go a.loopUDPOOBIn() } else { go a.loopUDPOOBInThreadSafe() } } else { if _, threadUnsafeHandler := common.Cast[N.ThreadUnsafeWriter](a.packetUpstream); !threadUnsafeHandler { go a.loopUDPIn() } else { go a.loopUDPInThreadSafe() } go a.loopUDPOut() } a.logger.Info("udp server started at ", udpConn.LocalAddr()) } if a.setSystemProxy { err := settings.SetSystemProxy(M.SocksaddrFromNet(a.tcpListener.Addr()).Port, a.protocol == C.TypeMixed) if err != nil { return E.Cause(err, "set system proxy") } } return nil } func (a *myInboundAdapter) Close() error { var err error if a.setSystemProxy { err = settings.ClearSystemProxy() } return E.Errors(err, common.Close( common.PtrOrNil(a.tcpListener), common.PtrOrNil(a.udpConn), )) } func (a *myInboundAdapter) upstreamHandler(metadata adapter.InboundContext) adapter.UpstreamHandlerAdapter { return adapter.NewUpstreamHandler(metadata, a.newConnection, a.streamPacketConnection, a) } func (a *myInboundAdapter) upstreamContextHandler() adapter.UpstreamHandlerAdapter { return adapter.NewUpstreamContextHandler(a.newConnection, a.newPacketConnection, a) } func (a *myInboundAdapter) newConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error { a.logger.InfoContext(ctx, "inbound connection to ", metadata.Destination) return a.router.RouteConnection(ctx, conn, metadata) } func (a *myInboundAdapter) streamPacketConnection(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext) error { a.logger.InfoContext(ctx, "inbound packet connection to ", metadata.Destination) return a.router.RoutePacketConnection(ctx, conn, metadata) } func (a *myInboundAdapter) newPacketConnection(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext) error { ctx = log.ContextWithNewID(ctx) a.logger.InfoContext(ctx, "inbound packet connection from ", metadata.Source) a.logger.InfoContext(ctx, "inbound packet connection to ", metadata.Destination) return a.router.RoutePacketConnection(ctx, conn, metadata) } func (a *myInboundAdapter) loopTCPIn() { tcpListener := a.tcpListener for { conn, err := tcpListener.Accept() if err != nil { return } go func() { ctx := log.ContextWithNewID(a.ctx) var metadata adapter.InboundContext metadata.Inbound = a.tag metadata.InboundType = a.protocol metadata.SniffEnabled = a.listenOptions.SniffEnabled metadata.SniffOverrideDestination = a.listenOptions.SniffOverrideDestination metadata.DomainStrategy = dns.DomainStrategy(a.listenOptions.DomainStrategy) metadata.Network = C.NetworkTCP metadata.Source = M.SocksaddrFromNet(conn.RemoteAddr()) a.logger.InfoContext(ctx, "inbound connection from ", metadata.Source) hErr := a.connHandler.NewConnection(ctx, conn, metadata) if hErr != nil { conn.Close() a.NewError(ctx, E.Cause(hErr, "process connection from ", metadata.Source)) } }() } } func (a *myInboundAdapter) loopUDPIn() { defer close(a.packetOutboundClosed) _buffer := buf.StackNewPacket() defer common.KeepAlive(_buffer) buffer := common.Dup(_buffer) defer buffer.Release() buffer.IncRef() defer buffer.DecRef() packetService := (*myInboundPacketAdapter)(a) for { buffer.Reset() n, addr, err := a.udpConn.ReadFromUDPAddrPort(buffer.FreeBytes()) if err != nil { return } buffer.Truncate(n) var metadata adapter.InboundContext metadata.Inbound = a.tag metadata.InboundType = a.protocol metadata.SniffEnabled = a.listenOptions.SniffEnabled metadata.SniffOverrideDestination = a.listenOptions.SniffOverrideDestination metadata.DomainStrategy = dns.DomainStrategy(a.listenOptions.DomainStrategy) metadata.Network = C.NetworkUDP metadata.Source = M.SocksaddrFromNetIP(addr) err = a.packetHandler.NewPacket(a.ctx, packetService, buffer, metadata) if err != nil { a.newError(E.Cause(err, "process packet from ", metadata.Source)) } } } func (a *myInboundAdapter) loopUDPOOBIn() { defer close(a.packetOutboundClosed) _buffer := buf.StackNewPacket() defer common.KeepAlive(_buffer) buffer := common.Dup(_buffer) defer buffer.Release() buffer.IncRef() defer buffer.DecRef() packetService := (*myInboundPacketAdapter)(a) oob := make([]byte, 1024) for { buffer.Reset() n, oobN, _, addr, err := a.udpConn.ReadMsgUDPAddrPort(buffer.FreeBytes(), oob) if err != nil { return } buffer.Truncate(n) var metadata adapter.InboundContext metadata.Inbound = a.tag metadata.InboundType = a.protocol metadata.SniffEnabled = a.listenOptions.SniffEnabled metadata.SniffOverrideDestination = a.listenOptions.SniffOverrideDestination metadata.DomainStrategy = dns.DomainStrategy(a.listenOptions.DomainStrategy) metadata.Network = C.NetworkUDP metadata.Source = M.SocksaddrFromNetIP(addr) err = a.oobPacketHandler.NewPacket(a.ctx, packetService, buffer, oob[:oobN], metadata) if err != nil { a.newError(E.Cause(err, "process packet from ", metadata.Source)) } } } func (a *myInboundAdapter) loopUDPInThreadSafe() { defer close(a.packetOutboundClosed) packetService := (*myInboundPacketAdapter)(a) for { buffer := buf.NewPacket() n, addr, err := a.udpConn.ReadFromUDPAddrPort(buffer.FreeBytes()) if err != nil { buffer.Release() return } buffer.Truncate(n) var metadata adapter.InboundContext metadata.Inbound = a.tag metadata.InboundType = a.protocol metadata.SniffEnabled = a.listenOptions.SniffEnabled metadata.SniffOverrideDestination = a.listenOptions.SniffOverrideDestination metadata.DomainStrategy = dns.DomainStrategy(a.listenOptions.DomainStrategy) metadata.Network = C.NetworkUDP metadata.Source = M.SocksaddrFromNetIP(addr) err = a.packetHandler.NewPacket(a.ctx, packetService, buffer, metadata) if err != nil { buffer.Release() a.newError(E.Cause(err, "process packet from ", metadata.Source)) } } } func (a *myInboundAdapter) loopUDPOOBInThreadSafe() { defer close(a.packetOutboundClosed) packetService := (*myInboundPacketAdapter)(a) oob := make([]byte, 1024) for { buffer := buf.NewPacket() n, oobN, _, addr, err := a.udpConn.ReadMsgUDPAddrPort(buffer.FreeBytes(), oob) if err != nil { buffer.Release() return } buffer.Truncate(n) var metadata adapter.InboundContext metadata.Inbound = a.tag metadata.InboundType = a.protocol metadata.SniffEnabled = a.listenOptions.SniffEnabled metadata.SniffOverrideDestination = a.listenOptions.SniffOverrideDestination metadata.DomainStrategy = dns.DomainStrategy(a.listenOptions.DomainStrategy) metadata.Network = C.NetworkUDP metadata.Source = M.SocksaddrFromNetIP(addr) err = a.oobPacketHandler.NewPacket(a.ctx, packetService, buffer, oob[:oobN], metadata) if err != nil { buffer.Release() a.newError(E.Cause(err, "process packet from ", metadata.Source)) } } } func (a *myInboundAdapter) loopUDPOut() { for { select { case packet := <-a.packetOutbound: err := a.writePacket(packet.buffer, packet.destination) if err != nil && !E.IsClosed(err) { a.newError(E.New("write back udp: ", err)) } continue case <-a.packetOutboundClosed: } for { select { case packet := <-a.packetOutbound: packet.buffer.Release() default: return } } } } func (a *myInboundAdapter) newError(err error) { a.logger.Error(err) } func (a *myInboundAdapter) NewError(ctx context.Context, err error) { NewError(a.logger, ctx, err) } func NewError(logger log.ContextLogger, ctx context.Context, err error) { common.Close(err) if E.IsClosedOrCanceled(err) { logger.TraceContext(ctx, "connection closed: ", err) return } logger.ErrorContext(ctx, err) } func (a *myInboundAdapter) writePacket(buffer *buf.Buffer, destination M.Socksaddr) error { defer buffer.Release() if destination.IsFqdn() { udpAddr, err := net.ResolveUDPAddr(C.NetworkUDP, destination.String()) if err != nil { return err } return common.Error(a.udpConn.WriteTo(buffer.Bytes(), udpAddr)) } if a.packetForce6 && destination.Addr.Is4() { destination.Addr = netip.AddrFrom16(destination.Addr.As16()) } return common.Error(a.udpConn.WriteToUDPAddrPort(buffer.Bytes(), destination.AddrPort())) } type myInboundPacketAdapter myInboundAdapter func (s *myInboundPacketAdapter) ReadPacket(buffer *buf.Buffer) (M.Socksaddr, error) { n, addr, err := s.udpConn.ReadFromUDPAddrPort(buffer.FreeBytes()) if err != nil { return M.Socksaddr{}, err } buffer.Truncate(n) return M.SocksaddrFromNetIP(addr), nil } func (s *myInboundPacketAdapter) WriteIsThreadUnsafe() { } type myInboundPacket struct { buffer *buf.Buffer destination M.Socksaddr } func (s *myInboundPacketAdapter) Upstream() any { return s.udpConn } func (s *myInboundPacketAdapter) WritePacket(buffer *buf.Buffer, destination M.Socksaddr) error { s.packetAccess.RLock() defer s.packetAccess.RUnlock() select { case <-s.packetOutboundClosed: return os.ErrClosed default: } s.packetOutbound <- &myInboundPacket{buffer, destination} return nil } func (s *myInboundPacketAdapter) Close() error { return s.udpConn.Close() } func (s *myInboundPacketAdapter) LocalAddr() net.Addr { return s.udpConn.LocalAddr() } func (s *myInboundPacketAdapter) SetDeadline(t time.Time) error { return s.udpConn.SetDeadline(t) } func (s *myInboundPacketAdapter) SetReadDeadline(t time.Time) error { return s.udpConn.SetReadDeadline(t) } func (s *myInboundPacketAdapter) SetWriteDeadline(t time.Time) error { return s.udpConn.SetWriteDeadline(t) }