ceremonyclient/go-libp2p/p2p/protocol/circuitv2/client/reservation.go

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2023-08-21 03:50:38 +00:00
package client
import (
"context"
"fmt"
"time"
"github.com/libp2p/go-libp2p/core/host"
"github.com/libp2p/go-libp2p/core/peer"
"github.com/libp2p/go-libp2p/core/peerstore"
"github.com/libp2p/go-libp2p/core/record"
pbv2 "github.com/libp2p/go-libp2p/p2p/protocol/circuitv2/pb"
"github.com/libp2p/go-libp2p/p2p/protocol/circuitv2/proto"
"github.com/libp2p/go-libp2p/p2p/protocol/circuitv2/util"
ma "github.com/multiformats/go-multiaddr"
)
var ReserveTimeout = time.Minute
// Reservation is a struct carrying information about a relay/v2 slot reservation.
type Reservation struct {
// Expiration is the expiration time of the reservation
Expiration time.Time
// Addrs contains the vouched public addresses of the reserving peer, which can be
// announced to the network
Addrs []ma.Multiaddr
// LimitDuration is the time limit for which the relay will keep a relayed connection
// open. If 0, there is no limit.
LimitDuration time.Duration
// LimitData is the number of bytes that the relay will relay in each direction before
// resetting a relayed connection.
LimitData uint64
// Voucher is a signed reservation voucher provided by the relay
Voucher *proto.ReservationVoucher
}
// ReservationError is the error returned on failure to reserve a slot in the relay
type ReservationError struct {
// Status is the status returned by the relay for rejecting the reservation
// request. It is set to pbv2.Status_CONNECTION_FAILED on other failures
Status pbv2.Status
// Reason is the reason for reservation failure
Reason string
err error
}
func (re ReservationError) Error() string {
return fmt.Sprintf("reservation error: status: %s reason: %s err: %s", pbv2.Status_name[int32(re.Status)], re.Reason, re.err)
}
func (re ReservationError) Unwrap() error {
return re.err
}
// Reserve reserves a slot in a relay and returns the reservation information.
// Clients must reserve slots in order for the relay to relay connections to them.
func Reserve(ctx context.Context, h host.Host, ai peer.AddrInfo) (*Reservation, error) {
if len(ai.Addrs) > 0 {
h.Peerstore().AddAddrs(ai.ID, ai.Addrs, peerstore.TempAddrTTL)
}
s, err := h.NewStream(ctx, ai.ID, proto.ProtoIDv2Hop)
if err != nil {
return nil, ReservationError{Status: pbv2.Status_CONNECTION_FAILED, Reason: "failed to open stream", err: err}
}
defer s.Close()
rd := util.NewDelimitedReader(s, maxMessageSize)
wr := util.NewDelimitedWriter(s)
defer rd.Close()
var msg pbv2.HopMessage
msg.Type = pbv2.HopMessage_RESERVE.Enum()
s.SetDeadline(time.Now().Add(ReserveTimeout))
if err := wr.WriteMsg(&msg); err != nil {
s.Reset()
return nil, ReservationError{Status: pbv2.Status_CONNECTION_FAILED, Reason: "error writing reservation message", err: err}
}
msg.Reset()
if err := rd.ReadMsg(&msg); err != nil {
s.Reset()
return nil, ReservationError{Status: pbv2.Status_CONNECTION_FAILED, Reason: "error reading reservation response message: %w", err: err}
}
if msg.GetType() != pbv2.HopMessage_STATUS {
return nil, ReservationError{
Status: pbv2.Status_MALFORMED_MESSAGE,
Reason: fmt.Sprintf("unexpected relay response: not a status message (%d)", msg.GetType()),
err: err}
}
if status := msg.GetStatus(); status != pbv2.Status_OK {
return nil, ReservationError{Status: msg.GetStatus(), Reason: "reservation failed"}
}
rsvp := msg.GetReservation()
if rsvp == nil {
return nil, ReservationError{Status: pbv2.Status_MALFORMED_MESSAGE, Reason: "missing reservation info"}
}
result := &Reservation{}
result.Expiration = time.Unix(int64(rsvp.GetExpire()), 0)
if result.Expiration.Before(time.Now()) {
return nil, ReservationError{
Status: pbv2.Status_MALFORMED_MESSAGE,
Reason: fmt.Sprintf("received reservation with expiration date in the past: %s", result.Expiration),
}
}
addrs := rsvp.GetAddrs()
result.Addrs = make([]ma.Multiaddr, 0, len(addrs))
for _, ab := range addrs {
a, err := ma.NewMultiaddrBytes(ab)
if err != nil {
log.Warnf("ignoring unparsable relay address: %s", err)
continue
}
result.Addrs = append(result.Addrs, a)
}
voucherBytes := rsvp.GetVoucher()
if voucherBytes != nil {
_, rec, err := record.ConsumeEnvelope(voucherBytes, proto.RecordDomain)
if err != nil {
return nil, ReservationError{
Status: pbv2.Status_MALFORMED_MESSAGE,
Reason: fmt.Sprintf("error consuming voucher envelope: %s", err),
err: err,
}
}
voucher, ok := rec.(*proto.ReservationVoucher)
if !ok {
return nil, ReservationError{
Status: pbv2.Status_MALFORMED_MESSAGE,
Reason: fmt.Sprintf("unexpected voucher record type: %+T", rec),
}
}
result.Voucher = voucher
}
limit := msg.GetLimit()
if limit != nil {
result.LimitDuration = time.Duration(limit.GetDuration()) * time.Second
result.LimitData = limit.GetData()
}
return result, nil
}