You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
555 lines
17 KiB
555 lines
17 KiB
package p2p
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/gogo/protobuf/proto"
|
|
"github.com/tendermint/tendermint/libs/log"
|
|
"github.com/tendermint/tendermint/libs/service"
|
|
)
|
|
|
|
// Router manages peer connections and routes messages between peers and reactor
|
|
// channels. This is an early prototype.
|
|
//
|
|
// Channels are registered via OpenChannel(). When called, we register an input
|
|
// message queue for the channel in channelQueues and spawn off a goroutine for
|
|
// Router.routeChannel(). This goroutine reads off outbound messages and puts
|
|
// them in the appropriate peer message queue, and processes peer errors which
|
|
// will close (and thus disconnect) the appriate peer queue. It runs until
|
|
// either the channel is closed by the caller or the router is stopped, at which
|
|
// point the input message queue is closed and removed.
|
|
//
|
|
// On startup, the router spawns off three primary goroutines that maintain
|
|
// connections to peers and run for the lifetime of the router:
|
|
//
|
|
// Router.dialPeers(): in a loop, asks the PeerManager for the next peer
|
|
// address to contact, resolves it into endpoints, and attempts to dial
|
|
// each one.
|
|
//
|
|
// Router.acceptPeers(): in a loop, waits for the next inbound connection
|
|
// from a peer, and checks with the PeerManager if it should be accepted.
|
|
//
|
|
// Router.evictPeers(): in a loop, asks the PeerManager for any connected
|
|
// peers to evict, and disconnects them.
|
|
//
|
|
// Once either an inbound or outbound connection has been made, an outbound
|
|
// message queue is registered in Router.peerQueues and a goroutine is spawned
|
|
// off for Router.routePeer() which will spawn off additional goroutines for
|
|
// Router.sendPeer() that sends outbound messages from the peer queue over the
|
|
// connection and for Router.receivePeer() that reads inbound messages from
|
|
// the connection and places them in the appropriate channel queue. When either
|
|
// goroutine exits, the connection and peer queue is closed, which will cause
|
|
// the other goroutines to close as well.
|
|
//
|
|
// The peerStore is used to coordinate peer connections, by only allowing a peer
|
|
// to be claimed (owned) by a single caller at a time (both for outbound and
|
|
// inbound connections). This is done either via peerStore.Dispense() which
|
|
// dispenses and claims an eligible peer to dial, or via peerStore.Claim() which
|
|
// attempts to claim a given peer for an inbound connection. Peers must be
|
|
// returned to the peerStore with peerStore.Return() to release the claim. Over
|
|
// time, the peerStore will also do peer scheduling and prioritization, e.g.
|
|
// ensuring we do exponential backoff on dial failures and connecting to
|
|
// more important peers first (such as persistent peers and validators).
|
|
//
|
|
// An additional goroutine Router.broadcastPeerUpdates() is also spawned off
|
|
// on startup, which consumes peer updates from Router.peerUpdatesCh (currently
|
|
// only connections and disconnections), and broadcasts them to all peer update
|
|
// subscriptions registered via SubscribePeerUpdates().
|
|
//
|
|
// On router shutdown, we close Router.stopCh which will signal to all
|
|
// goroutines to terminate. This in turn will cause all pending channel/peer
|
|
// queues to close, and we wait for this as a signal that goroutines have ended.
|
|
//
|
|
// All message scheduling should be limited to the queue implementations used
|
|
// for channel queues and peer queues. All message sending throughout the router
|
|
// is blocking, and if any messages should be dropped or buffered this is the
|
|
// sole responsibility of the queue, such that we can limit this logic to a
|
|
// single place. There is currently only a FIFO queue implementation that always
|
|
// blocks and never drops messages, but this must be improved with other
|
|
// implementations. The only exception is that all message sending must also
|
|
// select on appropriate channel/queue/router closure signals, to avoid blocking
|
|
// forever on a channel that has no consumer.
|
|
type Router struct {
|
|
*service.BaseService
|
|
logger log.Logger
|
|
transports map[Protocol]Transport
|
|
peerManager *PeerManager
|
|
|
|
// FIXME: Consider using sync.Map.
|
|
peerMtx sync.RWMutex
|
|
peerQueues map[NodeID]queue
|
|
|
|
// FIXME: We don't strictly need to use a mutex for this if we seal the
|
|
// channels on router start. This depends on whether we want to allow
|
|
// dynamic channels in the future.
|
|
channelMtx sync.RWMutex
|
|
channelQueues map[ChannelID]queue
|
|
channelMessages map[ChannelID]proto.Message
|
|
|
|
// stopCh is used to signal router shutdown, by closing the channel.
|
|
stopCh chan struct{}
|
|
}
|
|
|
|
// NewRouter creates a new Router, dialing the given peers.
|
|
//
|
|
// FIXME: providing protocol/transport maps is cumbersome in tests, we should
|
|
// consider adding Protocols() to the Transport interface instead and register
|
|
// protocol/transport mappings automatically on a first-come basis.
|
|
func NewRouter(logger log.Logger, peerManager *PeerManager, transports map[Protocol]Transport) *Router {
|
|
router := &Router{
|
|
logger: logger,
|
|
transports: transports,
|
|
peerManager: peerManager,
|
|
stopCh: make(chan struct{}),
|
|
channelQueues: map[ChannelID]queue{},
|
|
channelMessages: map[ChannelID]proto.Message{},
|
|
peerQueues: map[NodeID]queue{},
|
|
}
|
|
router.BaseService = service.NewBaseService(logger, "router", router)
|
|
return router
|
|
}
|
|
|
|
// OpenChannel opens a new channel for the given message type. The caller must
|
|
// close the channel when done, and this must happen before the router stops.
|
|
func (r *Router) OpenChannel(id ChannelID, messageType proto.Message) (*Channel, error) {
|
|
// FIXME: NewChannel should take directional channels so we can pass
|
|
// queue.dequeue() instead of reaching inside for queue.queueCh.
|
|
queue := newFIFOQueue()
|
|
channel := NewChannel(id, messageType, queue.queueCh, make(chan Envelope), make(chan PeerError))
|
|
|
|
r.channelMtx.Lock()
|
|
defer r.channelMtx.Unlock()
|
|
|
|
if _, ok := r.channelQueues[id]; ok {
|
|
return nil, fmt.Errorf("channel %v already exists", id)
|
|
}
|
|
r.channelQueues[id] = queue
|
|
r.channelMessages[id] = messageType
|
|
|
|
go func() {
|
|
defer func() {
|
|
r.channelMtx.Lock()
|
|
delete(r.channelQueues, id)
|
|
delete(r.channelMessages, id)
|
|
r.channelMtx.Unlock()
|
|
queue.close()
|
|
}()
|
|
r.routeChannel(channel)
|
|
}()
|
|
|
|
return channel, nil
|
|
}
|
|
|
|
// routeChannel receives outbound messages and errors from a channel and routes
|
|
// them to the appropriate peer. It returns when either the channel is closed or
|
|
// the router is shutting down.
|
|
func (r *Router) routeChannel(channel *Channel) {
|
|
for {
|
|
select {
|
|
case envelope, ok := <-channel.outCh:
|
|
if !ok {
|
|
return
|
|
}
|
|
|
|
// FIXME: This is a bit unergonomic, maybe it'd be better for Wrap()
|
|
// to return a wrapped copy.
|
|
if _, ok := channel.messageType.(Wrapper); ok {
|
|
wrapper := proto.Clone(channel.messageType)
|
|
if err := wrapper.(Wrapper).Wrap(envelope.Message); err != nil {
|
|
r.Logger.Error("failed to wrap message", "err", err)
|
|
continue
|
|
}
|
|
envelope.Message = wrapper
|
|
}
|
|
envelope.channelID = channel.id
|
|
|
|
if envelope.Broadcast {
|
|
r.peerMtx.RLock()
|
|
peerQueues := make(map[NodeID]queue, len(r.peerQueues))
|
|
for peerID, peerQueue := range r.peerQueues {
|
|
peerQueues[peerID] = peerQueue
|
|
}
|
|
r.peerMtx.RUnlock()
|
|
|
|
for peerID, peerQueue := range peerQueues {
|
|
e := envelope
|
|
e.Broadcast = false
|
|
e.To = peerID
|
|
select {
|
|
case peerQueue.enqueue() <- e:
|
|
case <-peerQueue.closed():
|
|
case <-r.stopCh:
|
|
return
|
|
}
|
|
}
|
|
|
|
} else {
|
|
r.peerMtx.RLock()
|
|
peerQueue, ok := r.peerQueues[envelope.To]
|
|
r.peerMtx.RUnlock()
|
|
if !ok {
|
|
r.logger.Error("dropping message for non-connected peer",
|
|
"peer", envelope.To, "channel", channel.id)
|
|
continue
|
|
}
|
|
|
|
select {
|
|
case peerQueue.enqueue() <- envelope:
|
|
case <-peerQueue.closed():
|
|
r.logger.Error("dropping message for non-connected peer",
|
|
"peer", envelope.To, "channel", channel.id)
|
|
case <-r.stopCh:
|
|
return
|
|
}
|
|
}
|
|
|
|
case peerError, ok := <-channel.errCh:
|
|
if !ok {
|
|
return
|
|
}
|
|
// FIXME: We just disconnect the peer for now
|
|
r.logger.Error("peer error, disconnecting", "peer", peerError.PeerID, "err", peerError.Err)
|
|
r.peerMtx.RLock()
|
|
peerQueue, ok := r.peerQueues[peerError.PeerID]
|
|
r.peerMtx.RUnlock()
|
|
if ok {
|
|
peerQueue.close()
|
|
}
|
|
|
|
case <-channel.Done():
|
|
return
|
|
case <-r.stopCh:
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
// acceptPeers accepts inbound connections from peers on the given transport.
|
|
func (r *Router) acceptPeers(transport Transport) {
|
|
ctx := r.stopCtx()
|
|
for {
|
|
// FIXME: We may need transports to enforce some sort of rate limiting
|
|
// here (e.g. by IP address), or alternatively have PeerManager.Accepted()
|
|
// do it for us.
|
|
conn, err := transport.Accept(ctx)
|
|
switch err {
|
|
case nil:
|
|
case ErrTransportClosed{}, io.EOF, context.Canceled:
|
|
r.logger.Debug("stopping accept routine", "transport", transport)
|
|
return
|
|
default:
|
|
r.logger.Error("failed to accept connection", "transport", transport, "err", err)
|
|
continue
|
|
}
|
|
|
|
go func() {
|
|
defer func() {
|
|
_ = conn.Close()
|
|
}()
|
|
|
|
// FIXME: Because we do the handshake in each transport, rather than
|
|
// here in the Router, the remote peer will think they've
|
|
// successfully connected and start sending us messages, although we
|
|
// can end up rejecting the connection here. This can e.g. cause
|
|
// problems in tests, where because of race conditions a
|
|
// disconnection can cause the local node to immediately redial,
|
|
// while the remote node may not have completed the disconnection
|
|
// registration yet and reject the accept below.
|
|
//
|
|
// The Router should do the handshake, and we should check with the
|
|
// peer manager before completing the handshake -- this probably
|
|
// requires protocol changes to send an additional message when the
|
|
// handshake is accepted.
|
|
peerID := conn.NodeInfo().NodeID
|
|
if err := r.peerManager.Accepted(peerID); err != nil {
|
|
r.logger.Error("failed to accept connection", "peer", peerID, "err", err)
|
|
return
|
|
}
|
|
|
|
queue := newFIFOQueue()
|
|
r.peerMtx.Lock()
|
|
r.peerQueues[peerID] = queue
|
|
r.peerMtx.Unlock()
|
|
r.peerManager.Ready(peerID)
|
|
|
|
defer func() {
|
|
r.peerMtx.Lock()
|
|
delete(r.peerQueues, peerID)
|
|
r.peerMtx.Unlock()
|
|
queue.close()
|
|
if err := r.peerManager.Disconnected(peerID); err != nil {
|
|
r.logger.Error("failed to disconnect peer", "peer", peerID, "err", err)
|
|
}
|
|
}()
|
|
|
|
r.routePeer(peerID, conn, queue)
|
|
}()
|
|
}
|
|
}
|
|
|
|
// dialPeers maintains outbound connections to peers.
|
|
func (r *Router) dialPeers() {
|
|
ctx := r.stopCtx()
|
|
for {
|
|
peerID, address, err := r.peerManager.DialNext(ctx)
|
|
switch err {
|
|
case nil:
|
|
case context.Canceled:
|
|
r.logger.Debug("stopping dial routine")
|
|
return
|
|
default:
|
|
r.logger.Error("failed to find next peer to dial", "err", err)
|
|
return
|
|
}
|
|
|
|
go func() {
|
|
conn, err := r.dialPeer(ctx, address)
|
|
if errors.Is(err, context.Canceled) {
|
|
return
|
|
} else if err != nil {
|
|
r.logger.Error("failed to dial peer", "peer", peerID)
|
|
if err = r.peerManager.DialFailed(peerID, address); err != nil {
|
|
r.logger.Error("failed to report dial failure", "peer", peerID, "err", err)
|
|
}
|
|
return
|
|
}
|
|
defer conn.Close()
|
|
|
|
if err = r.peerManager.Dialed(peerID, address); err != nil {
|
|
r.logger.Error("failed to dial peer", "peer", peerID, "err", err)
|
|
return
|
|
}
|
|
|
|
queue := newFIFOQueue()
|
|
r.peerMtx.Lock()
|
|
r.peerQueues[peerID] = queue
|
|
r.peerMtx.Unlock()
|
|
r.peerManager.Ready(peerID)
|
|
|
|
defer func() {
|
|
r.peerMtx.Lock()
|
|
delete(r.peerQueues, peerID)
|
|
r.peerMtx.Unlock()
|
|
queue.close()
|
|
if err := r.peerManager.Disconnected(peerID); err != nil {
|
|
r.logger.Error("failed to disconnect peer", "peer", peerID, "err", err)
|
|
}
|
|
}()
|
|
|
|
r.routePeer(peerID, conn, queue)
|
|
}()
|
|
}
|
|
}
|
|
|
|
// dialPeer attempts to connect to a peer.
|
|
func (r *Router) dialPeer(ctx context.Context, address PeerAddress) (Connection, error) {
|
|
resolveCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
|
|
defer cancel()
|
|
|
|
r.logger.Info("resolving peer address", "address", address)
|
|
|
|
endpoints, err := address.Resolve(resolveCtx)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to resolve address %q: %w", address, err)
|
|
}
|
|
|
|
for _, endpoint := range endpoints {
|
|
t, ok := r.transports[endpoint.Protocol]
|
|
if !ok {
|
|
r.logger.Error("no transport found for protocol", "protocol", endpoint.Protocol)
|
|
continue
|
|
}
|
|
|
|
dialCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
|
|
defer cancel()
|
|
|
|
// FIXME: When we dial and handshake the peer, we should pass it
|
|
// appropriate address(es) it can use to dial us back. It can't use our
|
|
// remote endpoint, since TCP uses different port numbers for outbound
|
|
// connections than it does for inbound. Also, we may need to vary this
|
|
// by the peer's endpoint, since e.g. a peer on 192.168.0.0 can reach us
|
|
// on a private address on this endpoint, but a peer on the public
|
|
// Internet can't and needs a different public address.
|
|
conn, err := t.Dial(dialCtx, endpoint)
|
|
if err != nil {
|
|
r.logger.Error("failed to dial endpoint", "endpoint", endpoint, "err", err)
|
|
} else {
|
|
r.logger.Info("connected to peer", "peer", address.ID, "endpoint", endpoint)
|
|
return conn, nil
|
|
}
|
|
}
|
|
return nil, fmt.Errorf("failed to connect to peer via %q", address)
|
|
}
|
|
|
|
// routePeer routes inbound messages from a peer to channels, and also sends
|
|
// outbound queued messages to the peer. It will close the connection and send
|
|
// queue, using this as a signal to coordinate the internal receivePeer() and
|
|
// sendPeer() goroutines. It blocks until the peer is done, e.g. when the
|
|
// connection or queue is closed.
|
|
func (r *Router) routePeer(peerID NodeID, conn Connection, sendQueue queue) {
|
|
r.logger.Info("routing peer", "peer", peerID)
|
|
resultsCh := make(chan error, 2)
|
|
go func() {
|
|
resultsCh <- r.receivePeer(peerID, conn)
|
|
}()
|
|
go func() {
|
|
resultsCh <- r.sendPeer(peerID, conn, sendQueue)
|
|
}()
|
|
|
|
err := <-resultsCh
|
|
_ = conn.Close()
|
|
sendQueue.close()
|
|
if e := <-resultsCh; err == nil {
|
|
// The first err was nil, so we update it with the second result,
|
|
// which may or may not be nil.
|
|
err = e
|
|
}
|
|
switch err {
|
|
case nil, io.EOF, ErrTransportClosed{}:
|
|
r.logger.Info("peer disconnected", "peer", peerID)
|
|
default:
|
|
r.logger.Error("peer failure", "peer", peerID, "err", err)
|
|
}
|
|
}
|
|
|
|
// receivePeer receives inbound messages from a peer, deserializes them and
|
|
// passes them on to the appropriate channel.
|
|
func (r *Router) receivePeer(peerID NodeID, conn Connection) error {
|
|
for {
|
|
chID, bz, err := conn.ReceiveMessage()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
r.channelMtx.RLock()
|
|
queue, ok := r.channelQueues[ChannelID(chID)]
|
|
messageType := r.channelMessages[ChannelID(chID)]
|
|
r.channelMtx.RUnlock()
|
|
if !ok {
|
|
r.logger.Error("dropping message for unknown channel", "peer", peerID, "channel", chID)
|
|
continue
|
|
}
|
|
|
|
msg := proto.Clone(messageType)
|
|
if err := proto.Unmarshal(bz, msg); err != nil {
|
|
r.logger.Error("message decoding failed, dropping message", "peer", peerID, "err", err)
|
|
continue
|
|
}
|
|
if wrapper, ok := msg.(Wrapper); ok {
|
|
msg, err = wrapper.Unwrap()
|
|
if err != nil {
|
|
r.logger.Error("failed to unwrap message", "err", err)
|
|
continue
|
|
}
|
|
}
|
|
|
|
select {
|
|
// FIXME: ReceiveMessage() should return ChannelID.
|
|
case queue.enqueue() <- Envelope{channelID: ChannelID(chID), From: peerID, Message: msg}:
|
|
r.logger.Debug("received message", "peer", peerID, "message", msg)
|
|
case <-queue.closed():
|
|
r.logger.Error("channel closed, dropping message", "peer", peerID, "channel", chID)
|
|
case <-r.stopCh:
|
|
return nil
|
|
}
|
|
}
|
|
}
|
|
|
|
// sendPeer sends queued messages to a peer.
|
|
func (r *Router) sendPeer(peerID NodeID, conn Connection, queue queue) error {
|
|
for {
|
|
select {
|
|
case envelope := <-queue.dequeue():
|
|
bz, err := proto.Marshal(envelope.Message)
|
|
if err != nil {
|
|
r.logger.Error("failed to marshal message", "peer", peerID, "err", err)
|
|
continue
|
|
}
|
|
|
|
// FIXME: SendMessage() should take ChannelID.
|
|
_, err = conn.SendMessage(byte(envelope.channelID), bz)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
r.logger.Debug("sent message", "peer", envelope.To, "message", envelope.Message)
|
|
|
|
case <-queue.closed():
|
|
return nil
|
|
|
|
case <-r.stopCh:
|
|
return nil
|
|
}
|
|
}
|
|
}
|
|
|
|
// evictPeers evicts connected peers as requested by the peer manager.
|
|
func (r *Router) evictPeers() {
|
|
ctx := r.stopCtx()
|
|
for {
|
|
peerID, err := r.peerManager.EvictNext(ctx)
|
|
switch err {
|
|
case nil:
|
|
case context.Canceled:
|
|
r.logger.Debug("stopping evict routine")
|
|
return
|
|
default:
|
|
r.logger.Error("failed to find next peer to evict", "err", err)
|
|
return
|
|
}
|
|
|
|
r.logger.Info("evicting peer", "peer", peerID)
|
|
r.peerMtx.RLock()
|
|
if queue, ok := r.peerQueues[peerID]; ok {
|
|
queue.close()
|
|
}
|
|
r.peerMtx.RUnlock()
|
|
}
|
|
}
|
|
|
|
// OnStart implements service.Service.
|
|
func (r *Router) OnStart() error {
|
|
go r.dialPeers()
|
|
for _, transport := range r.transports {
|
|
go r.acceptPeers(transport)
|
|
}
|
|
go r.evictPeers()
|
|
return nil
|
|
}
|
|
|
|
// OnStop implements service.Service.
|
|
func (r *Router) OnStop() {
|
|
// Collect all active queues, so we can wait for them to close.
|
|
queues := []queue{}
|
|
r.channelMtx.RLock()
|
|
for _, q := range r.channelQueues {
|
|
queues = append(queues, q)
|
|
}
|
|
r.channelMtx.RUnlock()
|
|
r.peerMtx.RLock()
|
|
for _, q := range r.peerQueues {
|
|
queues = append(queues, q)
|
|
}
|
|
r.peerMtx.RUnlock()
|
|
|
|
// Signal router shutdown, and wait for queues (and thus goroutines)
|
|
// to complete.
|
|
close(r.stopCh)
|
|
for _, q := range queues {
|
|
<-q.closed()
|
|
}
|
|
}
|
|
|
|
// stopCtx returns a context that is cancelled when the router stops.
|
|
func (r *Router) stopCtx() context.Context {
|
|
ctx, cancel := context.WithCancel(context.Background())
|
|
go func() {
|
|
<-r.stopCh
|
|
cancel()
|
|
}()
|
|
return ctx
|
|
}
|