package freedom //go:generate go run github.com/xtls/xray-core/common/errors/errorgen import ( "context" "time" "github.com/xtls/xray-core/common" "github.com/xtls/xray-core/common/buf" "github.com/xtls/xray-core/common/dice" "github.com/xtls/xray-core/common/net" "github.com/xtls/xray-core/common/retry" "github.com/xtls/xray-core/common/session" "github.com/xtls/xray-core/common/signal" "github.com/xtls/xray-core/common/task" "github.com/xtls/xray-core/core" "github.com/xtls/xray-core/features/dns" "github.com/xtls/xray-core/features/policy" "github.com/xtls/xray-core/features/stats" "github.com/xtls/xray-core/transport" "github.com/xtls/xray-core/transport/internet" ) func init() { common.Must(common.RegisterConfig((*Config)(nil), func(ctx context.Context, config interface{}) (interface{}, error) { h := new(Handler) if err := core.RequireFeatures(ctx, func(pm policy.Manager, d dns.Client) error { return h.Init(config.(*Config), pm, d) }); err != nil { return nil, err } return h, nil })) } // Handler handles Freedom connections. type Handler struct { policyManager policy.Manager dns dns.Client config *Config } // Init initializes the Handler with necessary parameters. func (h *Handler) Init(config *Config, pm policy.Manager, d dns.Client) error { h.config = config h.policyManager = pm h.dns = d return nil } func (h *Handler) policy() policy.Session { p := h.policyManager.ForLevel(h.config.UserLevel) if h.config.Timeout > 0 && h.config.UserLevel == 0 { p.Timeouts.ConnectionIdle = time.Duration(h.config.Timeout) * time.Second } return p } func (h *Handler) resolveIP(ctx context.Context, domain string, localAddr net.Address) net.Address { var option dns.IPOption = dns.IPOption{ IPv4Enable: true, IPv6Enable: true, FakeEnable: false, } if h.config.DomainStrategy == Config_USE_IP4 || (localAddr != nil && localAddr.Family().IsIPv4()) { option = dns.IPOption{ IPv4Enable: true, IPv6Enable: false, FakeEnable: false, } } else if h.config.DomainStrategy == Config_USE_IP6 || (localAddr != nil && localAddr.Family().IsIPv6()) { option = dns.IPOption{ IPv4Enable: false, IPv6Enable: true, FakeEnable: false, } } ips, err := h.dns.LookupIP(domain, option) if err != nil { newError("failed to get IP address for domain ", domain).Base(err).WriteToLog(session.ExportIDToError(ctx)) } if len(ips) == 0 { return nil } return net.IPAddress(ips[dice.Roll(len(ips))]) } func isValidAddress(addr *net.IPOrDomain) bool { if addr == nil { return false } a := addr.AsAddress() return a != net.AnyIP } // Process implements proxy.Outbound. func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer internet.Dialer) error { outbound := session.OutboundFromContext(ctx) if outbound == nil || !outbound.Target.IsValid() { return newError("target not specified.") } destination := outbound.Target UDPOverride := net.UDPDestination(nil, 0) if h.config.DestinationOverride != nil { server := h.config.DestinationOverride.Server if isValidAddress(server.Address) { destination.Address = server.Address.AsAddress() UDPOverride.Address = destination.Address } if server.Port != 0 { destination.Port = net.Port(server.Port) UDPOverride.Port = destination.Port } } newError("opening connection to ", destination).WriteToLog(session.ExportIDToError(ctx)) input := link.Reader output := link.Writer var conn internet.Connection err := retry.ExponentialBackoff(5, 100).On(func() error { dialDest := destination if h.config.useIP() && dialDest.Address.Family().IsDomain() { ip := h.resolveIP(ctx, dialDest.Address.Domain(), dialer.Address()) if ip != nil { dialDest = net.Destination{ Network: dialDest.Network, Address: ip, Port: dialDest.Port, } newError("dialing to ", dialDest).WriteToLog(session.ExportIDToError(ctx)) } } rawConn, err := dialer.Dial(ctx, dialDest) if err != nil { return err } conn = rawConn return nil }) if err != nil { return newError("failed to open connection to ", destination).Base(err) } defer conn.Close() plcy := h.policy() ctx, cancel := context.WithCancel(ctx) timer := signal.CancelAfterInactivity(ctx, cancel, plcy.Timeouts.ConnectionIdle) requestDone := func() error { defer timer.SetTimeout(plcy.Timeouts.DownlinkOnly) var writer buf.Writer if destination.Network == net.Network_TCP { writer = buf.NewWriter(conn) } else { writer = NewPacketWriter(conn, h, ctx, UDPOverride) } if err := buf.Copy(input, writer, buf.UpdateActivity(timer)); err != nil { return newError("failed to process request").Base(err) } return nil } responseDone := func() error { defer timer.SetTimeout(plcy.Timeouts.UplinkOnly) var reader buf.Reader if destination.Network == net.Network_TCP { reader = buf.NewReader(conn) } else { reader = NewPacketReader(conn, UDPOverride) } if err := buf.Copy(reader, output, buf.UpdateActivity(timer)); err != nil { return newError("failed to process response").Base(err) } return nil } if err := task.Run(ctx, requestDone, task.OnSuccess(responseDone, task.Close(output))); err != nil { return newError("connection ends").Base(err) } return nil } func NewPacketReader(conn net.Conn, UDPOverride net.Destination) buf.Reader { iConn := conn statConn, ok := iConn.(*internet.StatCouterConnection) if ok { iConn = statConn.Connection } var counter stats.Counter if statConn != nil { counter = statConn.ReadCounter } if c, ok := iConn.(*internet.PacketConnWrapper); ok && UDPOverride.Address == nil && UDPOverride.Port == 0 { return &PacketReader{ PacketConnWrapper: c, Counter: counter, } } return &buf.PacketReader{Reader: conn} } type PacketReader struct { *internet.PacketConnWrapper stats.Counter } func (r *PacketReader) ReadMultiBuffer() (buf.MultiBuffer, error) { b := buf.New() b.Resize(0, buf.Size) n, d, err := r.PacketConnWrapper.ReadFrom(b.Bytes()) if err != nil { b.Release() return nil, err } b.Resize(0, int32(n)) b.UDP = &net.Destination{ Address: net.IPAddress(d.(*net.UDPAddr).IP), Port: net.Port(d.(*net.UDPAddr).Port), Network: net.Network_UDP, } if r.Counter != nil { r.Counter.Add(int64(n)) } return buf.MultiBuffer{b}, nil } func NewPacketWriter(conn net.Conn, h *Handler, ctx context.Context, UDPOverride net.Destination) buf.Writer { iConn := conn statConn, ok := iConn.(*internet.StatCouterConnection) if ok { iConn = statConn.Connection } var counter stats.Counter if statConn != nil { counter = statConn.WriteCounter } if c, ok := iConn.(*internet.PacketConnWrapper); ok { return &PacketWriter{ PacketConnWrapper: c, Counter: counter, Handler: h, Context: ctx, UDPOverride: UDPOverride, } } return &buf.SequentialWriter{Writer: conn} } type PacketWriter struct { *internet.PacketConnWrapper stats.Counter *Handler context.Context UDPOverride net.Destination } func (w *PacketWriter) WriteMultiBuffer(mb buf.MultiBuffer) error { for { mb2, b := buf.SplitFirst(mb) mb = mb2 if b == nil { break } var n int var err error if b.UDP != nil { if w.UDPOverride.Address != nil { b.UDP.Address = w.UDPOverride.Address } if w.UDPOverride.Port != 0 { b.UDP.Port = w.UDPOverride.Port } if w.Handler.config.useIP() && b.UDP.Address.Family().IsDomain() { ip := w.Handler.resolveIP(w.Context, b.UDP.Address.Domain(), nil) if ip != nil { b.UDP.Address = ip } } destAddr, _ := net.ResolveUDPAddr("udp", b.UDP.NetAddr()) if destAddr == nil { b.Release() continue } n, err = w.PacketConnWrapper.WriteTo(b.Bytes(), destAddr) } else { n, err = w.PacketConnWrapper.Write(b.Bytes()) } b.Release() if err != nil { buf.ReleaseMulti(mb) return err } if w.Counter != nil { w.Counter.Add(int64(n)) } } return nil }