package freedom //go:generate go run $GOPATH/src/v2ray.com/core/tools/generrorgen/main.go -pkg freedom -path Proxy,Freedom import ( "context" "runtime" "time" "v2ray.com/core/app" "v2ray.com/core/app/dns" "v2ray.com/core/app/log" "v2ray.com/core/common" "v2ray.com/core/common/buf" "v2ray.com/core/common/dice" "v2ray.com/core/common/net" "v2ray.com/core/common/retry" "v2ray.com/core/common/signal" "v2ray.com/core/proxy" "v2ray.com/core/transport/internet" "v2ray.com/core/transport/ray" ) type Handler struct { domainStrategy Config_DomainStrategy timeout uint32 dns dns.Server destOverride *DestinationOverride } func New(ctx context.Context, config *Config) (*Handler, error) { space := app.SpaceFromContext(ctx) if space == nil { return nil, newError("no space in context") } f := &Handler{ domainStrategy: config.DomainStrategy, timeout: config.Timeout, destOverride: config.DestinationOverride, } space.OnInitialize(func() error { if config.DomainStrategy == Config_USE_IP { f.dns = dns.FromSpace(space) if f.dns == nil { return newError("DNS server is not found in the space") } } return nil }) return f, nil } func (v *Handler) ResolveIP(destination net.Destination) net.Destination { if !destination.Address.Family().IsDomain() { return destination } ips := v.dns.Get(destination.Address.Domain()) if len(ips) == 0 { log.Trace(newError("DNS returns nil answer. Keep domain as is.")) return destination } ip := ips[dice.Roll(len(ips))] newDest := net.Destination{ Network: destination.Network, Address: net.IPAddress(ip), Port: destination.Port, } log.Trace(newError("changing destination from ", destination, " to ", newDest)) return newDest } func (v *Handler) Process(ctx context.Context, outboundRay ray.OutboundRay, dialer proxy.Dialer) error { destination, _ := proxy.TargetFromContext(ctx) if v.destOverride != nil { server := v.destOverride.Server destination = net.Destination{ Network: destination.Network, Address: server.Address.AsAddress(), Port: net.Port(server.Port), } } log.Trace(newError("opening connection to ", destination)) input := outboundRay.OutboundInput() output := outboundRay.OutboundOutput() var conn internet.Connection if v.domainStrategy == Config_USE_IP && destination.Address.Family().IsDomain() { destination = v.ResolveIP(destination) } err := retry.ExponentialBackoff(5, 100).On(func() error { rawConn, err := dialer.Dial(ctx, destination) 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() timeout := time.Second * time.Duration(v.timeout) if timeout == 0 { timeout = time.Minute * 5 } ctx, timer := signal.CancelAfterInactivity(ctx, timeout) requestDone := signal.ExecuteAsync(func() error { var writer buf.Writer if destination.Network == net.Network_TCP { writer = buf.NewWriter(conn) } else { writer = buf.NewSequentialWriter(conn) } if err := buf.Copy(input, writer, buf.UpdateActivity(timer)); err != nil { return newError("failed to process request").Base(err) } return nil }) responseDone := signal.ExecuteAsync(func() error { defer output.Close() v2reader := buf.NewReader(conn) if err := buf.Copy(v2reader, output, buf.UpdateActivity(timer)); err != nil { return newError("failed to process response").Base(err) } return nil }) if err := signal.ErrorOrFinish2(ctx, requestDone, responseDone); err != nil { input.CloseError() output.CloseError() return newError("connection ends").Base(err) } runtime.KeepAlive(timer) return nil } func init() { common.Must(common.RegisterConfig((*Config)(nil), func(ctx context.Context, config interface{}) (interface{}, error) { return New(ctx, config.(*Config)) })) }