// NewDHT creates a new DHT object with the given peer as the 'local' host
func NewDHT(ctx context.Context, h host.Host, dstore ds.Datastore) *IpfsDHT {
dht := new(IpfsDHT)
dht.datastore = dstore
dht.self = h.ID()
dht.peerstore = h.Peerstore()
dht.host = h
// register for network notifs.
dht.host.Network().Notify((*netNotifiee)(dht))
dht.proc = goprocess.WithTeardown(func() error {
// remove ourselves from network notifs.
dht.host.Network().StopNotify((*netNotifiee)(dht))
return nil
})
dht.ctx = ctx
h.SetStreamHandler(ProtocolDHT, dht.handleNewStream)
dht.providers = NewProviderManager(dht.ctx, dht.self)
dht.proc.AddChild(dht.providers.proc)
goprocessctx.CloseAfterContext(dht.proc, ctx)
dht.routingTable = kb.NewRoutingTable(20, kb.ConvertPeerID(dht.self), time.Minute, dht.peerstore)
dht.birth = time.Now()
dht.Validator = make(record.Validator)
dht.Validator["pk"] = record.PublicKeyValidator
dht.Selector = make(record.Selector)
dht.Selector["pk"] = record.PublicKeySelector
return dht
}
func bootstrapConnect(ctx context.Context, ph host.Host, peers []peer.PeerInfo) error {
if len(peers) < 1 {
return ErrNotEnoughBootstrapPeers
}
errs := make(chan error, len(peers))
var wg sync.WaitGroup
for _, p := range peers {
// performed asynchronously because when performed synchronously, if
// one `Connect` call hangs, subsequent calls are more likely to
// fail/abort due to an expiring context.
// Also, performed asynchronously for dial speed.
wg.Add(1)
go func(p peer.PeerInfo) {
defer wg.Done()
defer log.EventBegin(ctx, "bootstrapDial", ph.ID(), p.ID).Done()
log.Debugf("%s bootstrapping to %s", ph.ID(), p.ID)
ph.Peerstore().AddAddrs(p.ID, p.Addrs, peer.PermanentAddrTTL)
if err := ph.Connect(ctx, p); err != nil {
log.Event(ctx, "bootstrapDialFailed", p.ID)
log.Debugf("failed to bootstrap with %v: %s", p.ID, err)
errs <- err
return
}
log.Event(ctx, "bootstrapDialSuccess", p.ID)
log.Infof("bootstrapped with %v", p.ID)
}(p)
}
wg.Wait()
// our failure condition is when no connection attempt succeeded.
// So drain the errs channel, counting the results.
close(errs)
count := 0
var err error
for err = range errs {
if err != nil {
count++
}
}
if count == len(peers) {
return fmt.Errorf("failed to bootstrap. %s", err)
}
return nil
}
func bootstrapRound(ctx context.Context, host host.Host, cfg BootstrapConfig) error {
ctx, cancel := context.WithTimeout(ctx, cfg.ConnectionTimeout)
defer cancel()
id := host.ID()
// get bootstrap peers from config. retrieving them here makes
// sure we remain observant of changes to client configuration.
peers := cfg.BootstrapPeers()
// determine how many bootstrap connections to open
connected := host.Network().Peers()
if len(connected) >= cfg.MinPeerThreshold {
log.Event(ctx, "bootstrapSkip", id)
log.Debugf("%s core bootstrap skipped -- connected to %d (> %d) nodes",
id, len(connected), cfg.MinPeerThreshold)
return nil
}
numToDial := cfg.MinPeerThreshold - len(connected)
// filter out bootstrap nodes we are already connected to
var notConnected []peer.PeerInfo
for _, p := range peers {
if host.Network().Connectedness(p.ID) != inet.Connected {
notConnected = append(notConnected, p)
}
}
// if connected to all bootstrap peer candidates, exit
if len(notConnected) < 1 {
log.Debugf("%s no more bootstrap peers to create %d connections", id, numToDial)
return ErrNotEnoughBootstrapPeers
}
// connect to a random susbset of bootstrap candidates
randSubset := randomSubsetOfPeers(notConnected, numToDial)
defer log.EventBegin(ctx, "bootstrapStart", id).Done()
log.Debugf("%s bootstrapping to %d nodes: %s", id, numToDial, randSubset)
if err := bootstrapConnect(ctx, host, randSubset); err != nil {
return err
}
return nil
}