package freedom //go:generate go run $GOPATH/src/v2ray.com/core/common/errors/errorgen/main.go -pkg freedom -path Proxy,Freedom import ( "context" "time" "v2ray.com/core" "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/session" "v2ray.com/core/common/signal" "v2ray.com/core/common/task" "v2ray.com/core/proxy" "v2ray.com/core/transport/internet" ) // Handler handles Freedom connections. type Handler struct { policyManager core.PolicyManager dns core.DNSClient config Config } // New creates a new Freedom handler. func New(ctx context.Context, config *Config) (*Handler, error) { v := core.MustFromContext(ctx) f := &Handler{ config: *config, policyManager: v.PolicyManager(), dns: v.DNSClient(), } return f, nil } func (h *Handler) policy() core.Policy { 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) net.Address { if resolver, ok := proxy.ResolvedIPsFromContext(ctx); ok { ips := resolver.Resolve() if len(ips) == 0 { return nil } return ips[dice.Roll(len(ips))] } ips, err := h.dns.LookupIP(domain) 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 *core.Link, dialer proxy.Dialer) error { destination, _ := proxy.TargetFromContext(ctx) if h.config.DestinationOverride != nil { server := h.config.DestinationOverride.Server if isValidAddress(server.Address) { destination.Address = server.Address.AsAddress() } if server.Port != 0 { destination.Port = net.Port(server.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.DomainStrategy == Config_USE_IP && dialDest.Address.Family().IsDomain() { ip := h.resolveIP(ctx, dialDest.Address.Domain()) if ip != nil { dialDest = net.Destination{ Network: dialDest.Network, Address: ip, Port: dialDest.Port, } newError("dialing to 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() // nolint: errcheck 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 = &buf.SequentialWriter{Writer: conn} } 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) if err := buf.Copy(buf.NewReader(conn), output, buf.UpdateActivity(timer)); err != nil { return newError("failed to process response").Base(err) } return nil } if err := task.Run(task.WithContext(ctx), task.Parallel(requestDone, task.Single(responseDone, task.OnSuccess(task.Close(output)))))(); err != nil { return newError("connection ends").Base(err) } return nil } func init() { common.Must(common.RegisterConfig((*Config)(nil), func(ctx context.Context, config interface{}) (interface{}, error) { return New(ctx, config.(*Config)) })) }