123 lines
3.2 KiB
Go
123 lines
3.2 KiB
Go
package autonat
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import (
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"context"
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"fmt"
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"time"
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"github.com/libp2p/go-libp2p/core/host"
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"github.com/libp2p/go-libp2p/core/network"
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"github.com/libp2p/go-libp2p/core/peer"
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"github.com/libp2p/go-libp2p/p2p/host/autonat/pb"
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"github.com/libp2p/go-msgio/pbio"
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)
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// NewAutoNATClient creates a fresh instance of an AutoNATClient
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// If addrFunc is nil, h.Addrs will be used
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func NewAutoNATClient(h host.Host, addrFunc AddrFunc, mt MetricsTracer) Client {
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if addrFunc == nil {
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addrFunc = h.Addrs
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}
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return &client{h: h, addrFunc: addrFunc, mt: mt}
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}
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type client struct {
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h host.Host
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addrFunc AddrFunc
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mt MetricsTracer
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}
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// DialBack asks peer p to dial us back on all addresses returned by the addrFunc.
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// It blocks until we've received a response from the peer.
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//
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// Note: A returned error Message_E_DIAL_ERROR does not imply that the server
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// actually performed a dial attempt. Servers that run a version < v0.20.0 also
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// return Message_E_DIAL_ERROR if the dial was skipped due to the dialPolicy.
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func (c *client) DialBack(ctx context.Context, p peer.ID) error {
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s, err := c.h.NewStream(ctx, p, AutoNATProto)
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if err != nil {
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return err
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}
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if err := s.Scope().SetService(ServiceName); err != nil {
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log.Debugf("error attaching stream to autonat service: %s", err)
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s.Reset()
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return err
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}
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if err := s.Scope().ReserveMemory(maxMsgSize, network.ReservationPriorityAlways); err != nil {
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log.Debugf("error reserving memory for autonat stream: %s", err)
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s.Reset()
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return err
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}
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defer s.Scope().ReleaseMemory(maxMsgSize)
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s.SetDeadline(time.Now().Add(streamTimeout))
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// Might as well just reset the stream. Once we get to this point, we
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// don't care about being nice.
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defer s.Close()
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r := pbio.NewDelimitedReader(s, maxMsgSize)
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w := pbio.NewDelimitedWriter(s)
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req := newDialMessage(peer.AddrInfo{ID: c.h.ID(), Addrs: c.addrFunc()})
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if err := w.WriteMsg(req); err != nil {
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s.Reset()
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return err
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}
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var res pb.Message
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if err := r.ReadMsg(&res); err != nil {
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s.Reset()
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return err
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}
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if res.GetType() != pb.Message_DIAL_RESPONSE {
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s.Reset()
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return fmt.Errorf("unexpected response: %s", res.GetType().String())
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}
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status := res.GetDialResponse().GetStatus()
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if c.mt != nil {
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c.mt.ReceivedDialResponse(status)
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}
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switch status {
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case pb.Message_OK:
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return nil
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default:
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return Error{Status: status, Text: res.GetDialResponse().GetStatusText()}
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}
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}
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// Error wraps errors signalled by AutoNAT services
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type Error struct {
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Status pb.Message_ResponseStatus
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Text string
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}
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func (e Error) Error() string {
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return fmt.Sprintf("AutoNAT error: %s (%s)", e.Text, e.Status.String())
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}
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// IsDialError returns true if the error was due to a dial back failure
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func (e Error) IsDialError() bool {
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return e.Status == pb.Message_E_DIAL_ERROR
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}
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// IsDialRefused returns true if the error was due to a refusal to dial back
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func (e Error) IsDialRefused() bool {
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return e.Status == pb.Message_E_DIAL_REFUSED
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}
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// IsDialError returns true if the AutoNAT peer signalled an error dialing back
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func IsDialError(e error) bool {
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ae, ok := e.(Error)
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return ok && ae.IsDialError()
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}
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// IsDialRefused returns true if the AutoNAT peer signalled refusal to dial back
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func IsDialRefused(e error) bool {
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ae, ok := e.(Error)
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return ok && ae.IsDialRefused()
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}
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