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package p2p
import (
"errors"
"fmt"
"math/rand"
"net"
"time"
crypto "github.com/tendermint/go-crypto"
cfg "github.com/tendermint/tendermint/config"
cmn "github.com/tendermint/tmlibs/common"
)
const (
reconnectAttempts = 30
reconnectInterval = 3 * time.Second
)
type Reactor interface {
cmn.Service // Start, Stop
SetSwitch(*Switch)
GetChannels() []*ChannelDescriptor
AddPeer(peer *Peer)
RemovePeer(peer *Peer, reason interface{})
Receive(chID byte, peer *Peer, msgBytes []byte)
}
//--------------------------------------
type BaseReactor struct {
cmn.BaseService // Provides Start, Stop, .Quit
Switch *Switch
}
func NewBaseReactor(name string, impl Reactor) *BaseReactor {
return &BaseReactor{
BaseService: *cmn.NewBaseService(nil, name, impl),
Switch: nil,
}
}
func (br *BaseReactor) SetSwitch(sw *Switch) {
br.Switch = sw
}
func (_ *BaseReactor) GetChannels() []*ChannelDescriptor { return nil }
func (_ *BaseReactor) AddPeer(peer *Peer) {}
func (_ *BaseReactor) RemovePeer(peer *Peer, reason interface{}) {}
func (_ *BaseReactor) Receive(chID byte, peer *Peer, msgBytes []byte) {}
//-----------------------------------------------------------------------------
/*
The `Switch` handles peer connections and exposes an API to receive incoming messages
on `Reactors`. Each `Reactor` is responsible for handling incoming messages of one
or more `Channels`. So while sending outgoing messages is typically performed on the peer,
incoming messages are received on the reactor.
*/
type Switch struct {
cmn.BaseService
config *cfg.P2PConfig
peerConfig *PeerConfig
listeners []Listener
reactors map[string]Reactor
chDescs []*ChannelDescriptor
reactorsByCh map[byte]Reactor
peers *PeerSet
dialing *cmn.CMap
nodeInfo *NodeInfo // our node info
nodePrivKey crypto.PrivKeyEd25519 // our node privkey
filterConnByAddr func(net.Addr) error
filterConnByPubKey func(crypto.PubKeyEd25519) error
}
var (
ErrSwitchDuplicatePeer = errors.New("Duplicate peer")
)
func NewSwitch(config *cfg.P2PConfig) *Switch {
sw := &Switch{
config: config,
peerConfig: DefaultPeerConfig(),
reactors: make(map[string]Reactor),
chDescs: make([]*ChannelDescriptor, 0),
reactorsByCh: make(map[byte]Reactor),
peers: NewPeerSet(),
dialing: cmn.NewCMap(),
nodeInfo: nil,
}
sw.peerConfig.MConfig.flushThrottle = time.Duration(config.FlushThrottleTimeout) * time.Millisecond // TODO: collapse the peerConfig into the config ?
sw.BaseService = *cmn.NewBaseService(nil, "P2P Switch", sw)
return sw
}
// AddReactor adds the given reactor to the switch.
// NOTE: Not goroutine safe.
func (sw *Switch) AddReactor(name string, reactor Reactor) Reactor {
// Validate the reactor.
// No two reactors can share the same channel.
reactorChannels := reactor.GetChannels()
for _, chDesc := range reactorChannels {
chID := chDesc.ID
if sw.reactorsByCh[chID] != nil {
cmn.PanicSanity(fmt.Sprintf("Channel %X has multiple reactors %v & %v", chID, sw.reactorsByCh[chID], reactor))
}
sw.chDescs = append(sw.chDescs, chDesc)
sw.reactorsByCh[chID] = reactor
}
sw.reactors[name] = reactor
reactor.SetSwitch(sw)
return reactor
}
// Reactors returns a map of reactors registered on the switch.
// NOTE: Not goroutine safe.
func (sw *Switch) Reactors() map[string]Reactor {
return sw.reactors
}
// Reactor returns the reactor with the given name.
// NOTE: Not goroutine safe.
func (sw *Switch) Reactor(name string) Reactor {
return sw.reactors[name]
}
// AddListener adds the given listener to the switch for listening to incoming peer connections.
// NOTE: Not goroutine safe.
func (sw *Switch) AddListener(l Listener) {
sw.listeners = append(sw.listeners, l)
}
// Listeners returns the list of listeners the switch listens on.
// NOTE: Not goroutine safe.
func (sw *Switch) Listeners() []Listener {
return sw.listeners
}
// IsListening returns true if the switch has at least one listener.
// NOTE: Not goroutine safe.
func (sw *Switch) IsListening() bool {
return len(sw.listeners) > 0
}
// SetNodeInfo sets the switch's NodeInfo for checking compatibility and handshaking with other nodes.
// NOTE: Not goroutine safe.
func (sw *Switch) SetNodeInfo(nodeInfo *NodeInfo) {
sw.nodeInfo = nodeInfo
}
// NodeInfo returns the switch's NodeInfo.
// NOTE: Not goroutine safe.
func (sw *Switch) NodeInfo() *NodeInfo {
return sw.nodeInfo
}
// SetNodePrivKey sets the switche's private key for authenticated encryption.
// NOTE: Overwrites sw.nodeInfo.PubKey.
// NOTE: Not goroutine safe.
func (sw *Switch) SetNodePrivKey(nodePrivKey crypto.PrivKeyEd25519) {
sw.nodePrivKey = nodePrivKey
if sw.nodeInfo != nil {
sw.nodeInfo.PubKey = nodePrivKey.PubKey().Unwrap().(crypto.PubKeyEd25519)
}
}
// OnStart implements BaseService. It starts all the reactors, peers, and listeners.
func (sw *Switch) OnStart() error {
sw.BaseService.OnStart()
// Start reactors
for _, reactor := range sw.reactors {
_, err := reactor.Start()
if err != nil {
return err
}
}
// Start listeners
for _, listener := range sw.listeners {
go sw.listenerRoutine(listener)
}
return nil
}
// OnStop implements BaseService. It stops all listeners, peers, and reactors.
func (sw *Switch) OnStop() {
sw.BaseService.OnStop()
// Stop listeners
for _, listener := range sw.listeners {
listener.Stop()
}
sw.listeners = nil
// Stop peers
for _, peer := range sw.peers.List() {
peer.Stop()
sw.peers.Remove(peer)
}
// Stop reactors
for _, reactor := range sw.reactors {
reactor.Stop()
}
}
// AddPeer checks the given peer's validity, performs a handshake, and adds the peer to the switch
// and to all registered reactors.
// NOTE: This performs a blocking handshake before the peer is added.
// CONTRACT: If error is returned, peer is nil, and conn is immediately closed.
func (sw *Switch) AddPeer(peer *Peer) error {
if err := sw.FilterConnByAddr(peer.Addr()); err != nil {
return err
}
if err := sw.FilterConnByPubKey(peer.PubKey()); err != nil {
return err
}
if err := peer.HandshakeTimeout(sw.nodeInfo, time.Duration(sw.peerConfig.HandshakeTimeout*time.Second)); err != nil {
return err
}
// Avoid self
if sw.nodeInfo.PubKey.Equals(peer.PubKey().Wrap()) {
return errors.New("Ignoring connection from self")
}
// Check version, chain id
if err := sw.nodeInfo.CompatibleWith(peer.NodeInfo); err != nil {
return err
}
// Check for duplicate peer
if sw.peers.Has(peer.Key) {
return ErrSwitchDuplicatePeer
}
// Start peer
if sw.IsRunning() {
sw.startInitPeer(peer)
}
// Add the peer to .peers.
// We start it first so that a peer in the list is safe to Stop.
// It should not err since we already checked peers.Has()
if err := sw.peers.Add(peer); err != nil {
return err
}
sw.Logger.Info("Added peer", "peer", peer)
return nil
}
// FilterConnByAddr returns an error if connecting to the given address is forbidden.
func (sw *Switch) FilterConnByAddr(addr net.Addr) error {
if sw.filterConnByAddr != nil {
return sw.filterConnByAddr(addr)
}
return nil
}
// FilterConnByPubKey returns an error if connecting to the given public key is forbidden.
func (sw *Switch) FilterConnByPubKey(pubkey crypto.PubKeyEd25519) error {
if sw.filterConnByPubKey != nil {
return sw.filterConnByPubKey(pubkey)
}
return nil
}
// SetAddrFilter sets the function for filtering connections by address.
func (sw *Switch) SetAddrFilter(f func(net.Addr) error) {
sw.filterConnByAddr = f
}
// SetPubKeyFilter sets the function for filtering connections by public key.
func (sw *Switch) SetPubKeyFilter(f func(crypto.PubKeyEd25519) error) {
sw.filterConnByPubKey = f
}
func (sw *Switch) startInitPeer(peer *Peer) {
peer.Start() // spawn send/recv routines
for _, reactor := range sw.reactors {
reactor.AddPeer(peer)
}
}
// DialSeeds dials a list of seeds asynchronously in random order
func (sw *Switch) DialSeeds(addrBook *AddrBook, seeds []string) error {
netAddrs, err := NewNetAddressStrings(seeds)
if err != nil {
return err
}
if addrBook != nil {
// add seeds to `addrBook`
ourAddrS := sw.nodeInfo.ListenAddr
ourAddr, _ := NewNetAddressString(ourAddrS)
for _, netAddr := range netAddrs {
// do not add ourselves
if netAddr.Equals(ourAddr) {
continue
}
addrBook.AddAddress(netAddr, ourAddr)
}
addrBook.Save()
}
// permute the list, dial them in random order.
perm := rand.Perm(len(netAddrs))
for i := 0; i < len(perm); i++ {
go func(i int) {
time.Sleep(time.Duration(rand.Int63n(3000)) * time.Millisecond)
j := perm[i]
sw.dialSeed(netAddrs[j])
}(i)
}
return nil
}
func (sw *Switch) dialSeed(addr *NetAddress) {
peer, err := sw.DialPeerWithAddress(addr, true)
if err != nil {
sw.Logger.Error("Error dialing seed", "err", err)
} else {
sw.Logger.Info("Connected to seed", "peer", peer)
}
}
// DialPeerWithAddress dials the given peer and runs sw.AddPeer if it connects successfully.
// If `persistent == true`, the switch will always try to reconnect to this peer if the connection ever fails.
func (sw *Switch) DialPeerWithAddress(addr *NetAddress, persistent bool) (*Peer, error) {
sw.dialing.Set(addr.IP.String(), addr)
defer sw.dialing.Delete(addr.IP.String())
sw.Logger.Info("Dialing peer", "address", addr)
peer, err := newOutboundPeer(addr, sw.reactorsByCh, sw.chDescs, sw.StopPeerForError, sw.nodePrivKey, sw.peerConfig)
if err != nil {
sw.Logger.Error("Failed to dial peer", "address", addr, "err", err)
return nil, err
}
peer.SetLogger(sw.Logger.With("peer", addr))
if persistent {
peer.makePersistent()
}
err = sw.AddPeer(peer)
if err != nil {
sw.Logger.Error("Failed to add peer", "address", addr, "err", err)
peer.CloseConn()
return nil, err
}
sw.Logger.Info("Dialed and added peer", "address", addr, "peer", peer)
return peer, nil
}
// IsDialing returns true if the switch is currently dialing the given address.
func (sw *Switch) IsDialing(addr *NetAddress) bool {
return sw.dialing.Has(addr.IP.String())
}
// Broadcast runs a go routine for each attempted send, which will block
// trying to send for defaultSendTimeoutSeconds. Returns a channel
// which receives success values for each attempted send (false if times out)
// NOTE: Broadcast uses goroutines, so order of broadcast may not be preserved.
// TODO: Something more intelligent.
func (sw *Switch) Broadcast(chID byte, msg interface{}) chan bool {
successChan := make(chan bool, len(sw.peers.List()))
sw.Logger.Debug("Broadcast", "channel", chID, "msg", msg)
for _, peer := range sw.peers.List() {
go func(peer *Peer) {
success := peer.Send(chID, msg)
successChan <- success
}(peer)
}
return successChan
}
// NumPeers returns the count of outbound/inbound and outbound-dialing peers.
func (sw *Switch) NumPeers() (outbound, inbound, dialing int) {
peers := sw.peers.List()
for _, peer := range peers {
if peer.outbound {
outbound++
} else {
inbound++
}
}
dialing = sw.dialing.Size()
return
}
// Peers returns the set of peers the switch is connected to.
func (sw *Switch) Peers() IPeerSet {
return sw.peers
}
// StopPeerForError disconnects from a peer due to external error.
// If the peer is persistent, it will attempt to reconnect.
// TODO: make record depending on reason.
func (sw *Switch) StopPeerForError(peer *Peer, reason interface{}) {
addr := NewNetAddress(peer.Addr())
sw.Logger.Error("Stopping peer for error", "peer", peer, "err", reason)
sw.stopAndRemovePeer(peer, reason)
if peer.IsPersistent() {
go func() {
sw.Logger.Info("Reconnecting to peer", "peer", peer)
for i := 1; i < reconnectAttempts; i++ {
if !sw.IsRunning() {
return
}
peer, err := sw.DialPeerWithAddress(addr, true)
if err != nil {
if i == reconnectAttempts {
sw.Logger.Info("Error reconnecting to peer. Giving up", "tries", i, "err", err)
return
}
sw.Logger.Info("Error reconnecting to peer. Trying again", "tries", i, "err", err)
time.Sleep(reconnectInterval)
continue
}
sw.Logger.Info("Reconnected to peer", "peer", peer)
return
}
}()
}
}
// StopPeerGracefully disconnects from a peer gracefully.
// TODO: handle graceful disconnects.
func (sw *Switch) StopPeerGracefully(peer *Peer) {
sw.Logger.Info("Stopping peer gracefully")
sw.stopAndRemovePeer(peer, nil)
}
func (sw *Switch) stopAndRemovePeer(peer *Peer, reason interface{}) {
sw.peers.Remove(peer)
peer.Stop()
for _, reactor := range sw.reactors {
reactor.RemovePeer(peer, reason)
}
}
func (sw *Switch) listenerRoutine(l Listener) {
for {
inConn, ok := <-l.Connections()
if !ok {
break
}
// ignore connection if we already have enough
maxPeers := sw.config.MaxNumPeers
if maxPeers <= sw.peers.Size() {
sw.Logger.Info("Ignoring inbound connection: already have enough peers", "address", inConn.RemoteAddr().String(), "numPeers", sw.peers.Size(), "max", maxPeers)
continue
}
// New inbound connection!
err := sw.addPeerWithConnectionAndConfig(inConn, sw.peerConfig)
if err != nil {
sw.Logger.Info("Ignoring inbound connection: error while adding peer", "address", inConn.RemoteAddr().String(), "err", err)
continue
}
// NOTE: We don't yet have the listening port of the
// remote (if they have a listener at all).
// The peerHandshake will handle that
}
// cleanup
}
//-----------------------------------------------------------------------------
type SwitchEventNewPeer struct {
Peer *Peer
}
type SwitchEventDonePeer struct {
Peer *Peer
Error interface{}
}
//------------------------------------------------------------------
// Switches connected via arbitrary net.Conn; useful for testing
// MakeConnectedSwitches returns n switches, connected according to the connect func.
// If connect==Connect2Switches, the switches will be fully connected.
// initSwitch defines how the ith switch should be initialized (ie. with what reactors).
// NOTE: panics if any switch fails to start.
func MakeConnectedSwitches(cfg *cfg.P2PConfig, n int, initSwitch func(int, *Switch) *Switch, connect func([]*Switch, int, int)) []*Switch {
switches := make([]*Switch, n)
for i := 0; i < n; i++ {
switches[i] = makeSwitch(cfg, i, "testing", "123.123.123", initSwitch)
}
if err := StartSwitches(switches); err != nil {
panic(err)
}
for i := 0; i < n; i++ {
for j := i; j < n; j++ {
connect(switches, i, j)
}
}
return switches
}
var PanicOnAddPeerErr = false
// Connect2Switches will connect switches i and j via net.Pipe()
// Blocks until a conection is established.
// NOTE: caller ensures i and j are within bounds
func Connect2Switches(switches []*Switch, i, j int) {
switchI := switches[i]
switchJ := switches[j]
c1, c2 := net.Pipe()
doneCh := make(chan struct{})
go func() {
err := switchI.addPeerWithConnection(c1)
if PanicOnAddPeerErr && err != nil {
panic(err)
}
doneCh <- struct{}{}
}()
go func() {
err := switchJ.addPeerWithConnection(c2)
if PanicOnAddPeerErr && err != nil {
panic(err)
}
doneCh <- struct{}{}
}()
<-doneCh
<-doneCh
}
// StartSwitches calls sw.Start() for each given switch.
// It returns the first encountered error.
func StartSwitches(switches []*Switch) error {
for _, s := range switches {
_, err := s.Start() // start switch and reactors
if err != nil {
return err
}
}
return nil
}
func makeSwitch(cfg *cfg.P2PConfig, i int, network, version string, initSwitch func(int, *Switch) *Switch) *Switch {
privKey := crypto.GenPrivKeyEd25519()
// new switch, add reactors
// TODO: let the config be passed in?
s := initSwitch(i, NewSwitch(cfg))
s.SetNodeInfo(&NodeInfo{
PubKey: privKey.PubKey().Unwrap().(crypto.PubKeyEd25519),
Moniker: cmn.Fmt("switch%d", i),
Network: network,
Version: version,
RemoteAddr: cmn.Fmt("%v:%v", network, rand.Intn(64512)+1023),
ListenAddr: cmn.Fmt("%v:%v", network, rand.Intn(64512)+1023),
})
s.SetNodePrivKey(privKey)
return s
}
func (sw *Switch) addPeerWithConnection(conn net.Conn) error {
peer, err := newInboundPeer(conn, sw.reactorsByCh, sw.chDescs, sw.StopPeerForError, sw.nodePrivKey, sw.peerConfig)
if err != nil {
conn.Close()
return err
}
peer.SetLogger(sw.Logger.With("peer", conn.RemoteAddr()))
if err = sw.AddPeer(peer); err != nil {
conn.Close()
return err
}
return nil
}
func (sw *Switch) addPeerWithConnectionAndConfig(conn net.Conn, config *PeerConfig) error {
peer, err := newInboundPeer(conn, sw.reactorsByCh, sw.chDescs, sw.StopPeerForError, sw.nodePrivKey, config)
if err != nil {
conn.Close()
return err
}
peer.SetLogger(sw.Logger.With("peer", conn.RemoteAddr()))
if err = sw.AddPeer(peer); err != nil {
conn.Close()
return err
}
return nil
}