package p2p
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import (
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"errors"
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"fmt"
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"math/rand"
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"net"
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"time"
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crypto "github.com/tendermint/go-crypto"
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cfg "github.com/tendermint/tendermint/config"
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cmn "github.com/tendermint/tmlibs/common"
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)
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const (
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reconnectAttempts = 30
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reconnectInterval = 3 * time.Second
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)
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type Reactor interface {
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cmn.Service // Start, Stop
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SetSwitch(*Switch)
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GetChannels() []*ChannelDescriptor
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AddPeer(peer Peer)
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RemovePeer(peer Peer, reason interface{})
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Receive(chID byte, peer Peer, msgBytes []byte) // CONTRACT: msgBytes are not nil
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}
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//--------------------------------------
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type BaseReactor struct {
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cmn.BaseService // Provides Start, Stop, .Quit
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Switch *Switch
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}
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func NewBaseReactor(name string, impl Reactor) *BaseReactor {
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return &BaseReactor{
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BaseService: *cmn.NewBaseService(nil, name, impl),
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Switch: nil,
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}
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}
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func (br *BaseReactor) SetSwitch(sw *Switch) {
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br.Switch = sw
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}
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func (_ *BaseReactor) GetChannels() []*ChannelDescriptor { return nil }
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func (_ *BaseReactor) AddPeer(peer Peer) {}
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func (_ *BaseReactor) RemovePeer(peer Peer, reason interface{}) {}
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func (_ *BaseReactor) Receive(chID byte, peer Peer, msgBytes []byte) {}
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//-----------------------------------------------------------------------------
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/*
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The `Switch` handles peer connections and exposes an API to receive incoming messages
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on `Reactors`. Each `Reactor` is responsible for handling incoming messages of one
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or more `Channels`. So while sending outgoing messages is typically performed on the peer,
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incoming messages are received on the reactor.
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*/
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type Switch struct {
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cmn.BaseService
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config *cfg.P2PConfig
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peerConfig *PeerConfig
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listeners []Listener
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reactors map[string]Reactor
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chDescs []*ChannelDescriptor
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reactorsByCh map[byte]Reactor
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peers *PeerSet
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dialing *cmn.CMap
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nodeInfo *NodeInfo // our node info
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nodePrivKey crypto.PrivKeyEd25519 // our node privkey
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filterConnByAddr func(net.Addr) error
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filterConnByPubKey func(crypto.PubKeyEd25519) error
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}
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var (
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ErrSwitchDuplicatePeer = errors.New("Duplicate peer")
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)
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func NewSwitch(config *cfg.P2PConfig) *Switch {
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sw := &Switch{
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config: config,
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peerConfig: DefaultPeerConfig(),
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reactors: make(map[string]Reactor),
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chDescs: make([]*ChannelDescriptor, 0),
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reactorsByCh: make(map[byte]Reactor),
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peers: NewPeerSet(),
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dialing: cmn.NewCMap(),
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nodeInfo: nil,
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}
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// TODO: collapse the peerConfig into the config ?
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sw.peerConfig.MConfig.flushThrottle = time.Duration(config.FlushThrottleTimeout) * time.Millisecond
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sw.peerConfig.MConfig.SendRate = config.SendRate
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sw.peerConfig.MConfig.RecvRate = config.RecvRate
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sw.peerConfig.MConfig.maxMsgPacketPayloadSize = config.MaxMsgPacketPayloadSize
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sw.BaseService = *cmn.NewBaseService(nil, "P2P Switch", sw)
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return sw
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}
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// AddReactor adds the given reactor to the switch.
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// NOTE: Not goroutine safe.
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func (sw *Switch) AddReactor(name string, reactor Reactor) Reactor {
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// Validate the reactor.
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// No two reactors can share the same channel.
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reactorChannels := reactor.GetChannels()
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for _, chDesc := range reactorChannels {
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chID := chDesc.ID
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if sw.reactorsByCh[chID] != nil {
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cmn.PanicSanity(fmt.Sprintf("Channel %X has multiple reactors %v & %v", chID, sw.reactorsByCh[chID], reactor))
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}
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sw.chDescs = append(sw.chDescs, chDesc)
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sw.reactorsByCh[chID] = reactor
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}
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sw.reactors[name] = reactor
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reactor.SetSwitch(sw)
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return reactor
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}
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// Reactors returns a map of reactors registered on the switch.
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// NOTE: Not goroutine safe.
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func (sw *Switch) Reactors() map[string]Reactor {
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return sw.reactors
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}
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// Reactor returns the reactor with the given name.
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// NOTE: Not goroutine safe.
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func (sw *Switch) Reactor(name string) Reactor {
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return sw.reactors[name]
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}
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// AddListener adds the given listener to the switch for listening to incoming peer connections.
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// NOTE: Not goroutine safe.
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func (sw *Switch) AddListener(l Listener) {
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sw.listeners = append(sw.listeners, l)
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}
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// Listeners returns the list of listeners the switch listens on.
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// NOTE: Not goroutine safe.
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func (sw *Switch) Listeners() []Listener {
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return sw.listeners
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}
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// IsListening returns true if the switch has at least one listener.
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// NOTE: Not goroutine safe.
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func (sw *Switch) IsListening() bool {
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return len(sw.listeners) > 0
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}
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// SetNodeInfo sets the switch's NodeInfo for checking compatibility and handshaking with other nodes.
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// NOTE: Not goroutine safe.
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func (sw *Switch) SetNodeInfo(nodeInfo *NodeInfo) {
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sw.nodeInfo = nodeInfo
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}
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// NodeInfo returns the switch's NodeInfo.
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// NOTE: Not goroutine safe.
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func (sw *Switch) NodeInfo() *NodeInfo {
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return sw.nodeInfo
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}
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// SetNodePrivKey sets the switch's private key for authenticated encryption.
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// NOTE: Overwrites sw.nodeInfo.PubKey.
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// NOTE: Not goroutine safe.
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func (sw *Switch) SetNodePrivKey(nodePrivKey crypto.PrivKeyEd25519) {
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sw.nodePrivKey = nodePrivKey
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if sw.nodeInfo != nil {
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sw.nodeInfo.PubKey = nodePrivKey.PubKey().Unwrap().(crypto.PubKeyEd25519)
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}
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}
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// OnStart implements BaseService. It starts all the reactors, peers, and listeners.
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func (sw *Switch) OnStart() error {
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if err := sw.BaseService.OnStart(); err != nil {
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return err
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}
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// Start reactors
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for _, reactor := range sw.reactors {
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_, err := reactor.Start()
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if err != nil {
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return err
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}
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}
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// Start listeners
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for _, listener := range sw.listeners {
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go sw.listenerRoutine(listener)
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}
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return nil
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}
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// OnStop implements BaseService. It stops all listeners, peers, and reactors.
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func (sw *Switch) OnStop() {
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sw.BaseService.OnStop()
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// Stop listeners
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for _, listener := range sw.listeners {
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listener.Stop()
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}
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sw.listeners = nil
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// Stop peers
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for _, peer := range sw.peers.List() {
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peer.Stop()
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sw.peers.Remove(peer)
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}
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// Stop reactors
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for _, reactor := range sw.reactors {
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reactor.Stop()
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}
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}
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// addPeer checks the given peer's validity, performs a handshake, and adds the
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// peer to the switch and to all registered reactors.
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// NOTE: This performs a blocking handshake before the peer is added.
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// NOTE: If error is returned, caller is responsible for calling peer.CloseConn()
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func (sw *Switch) addPeer(peer *peer) error {
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if err := sw.FilterConnByAddr(peer.Addr()); err != nil {
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return err
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}
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if err := sw.FilterConnByPubKey(peer.PubKey()); err != nil {
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return err
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}
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if err := peer.HandshakeTimeout(sw.nodeInfo, time.Duration(sw.peerConfig.HandshakeTimeout*time.Second)); err != nil {
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return err
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}
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// Avoid self
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if sw.nodeInfo.PubKey.Equals(peer.PubKey().Wrap()) {
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return errors.New("Ignoring connection from self")
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}
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// Check version, chain id
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if err := sw.nodeInfo.CompatibleWith(peer.NodeInfo()); err != nil {
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return err
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}
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// Check for duplicate peer
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if sw.peers.Has(peer.Key()) {
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return ErrSwitchDuplicatePeer
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}
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// Start peer
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if sw.IsRunning() {
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sw.startInitPeer(peer)
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}
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// Add the peer to .peers.
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// We start it first so that a peer in the list is safe to Stop.
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// It should not err since we already checked peers.Has().
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if err := sw.peers.Add(peer); err != nil {
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return err
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}
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sw.Logger.Info("Added peer", "peer", peer)
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return nil
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}
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// FilterConnByAddr returns an error if connecting to the given address is forbidden.
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func (sw *Switch) FilterConnByAddr(addr net.Addr) error {
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if sw.filterConnByAddr != nil {
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return sw.filterConnByAddr(addr)
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}
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return nil
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}
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// FilterConnByPubKey returns an error if connecting to the given public key is forbidden.
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func (sw *Switch) FilterConnByPubKey(pubkey crypto.PubKeyEd25519) error {
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if sw.filterConnByPubKey != nil {
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return sw.filterConnByPubKey(pubkey)
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}
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return nil
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}
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// SetAddrFilter sets the function for filtering connections by address.
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func (sw *Switch) SetAddrFilter(f func(net.Addr) error) {
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sw.filterConnByAddr = f
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}
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// SetPubKeyFilter sets the function for filtering connections by public key.
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func (sw *Switch) SetPubKeyFilter(f func(crypto.PubKeyEd25519) error) {
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sw.filterConnByPubKey = f
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}
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func (sw *Switch) startInitPeer(peer *peer) {
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_, err := peer.Start() // spawn send/recv routines
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if err != nil {
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// Should never happen
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sw.Logger.Error("Error starting peer", "peer", peer, "err", err)
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}
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for _, reactor := range sw.reactors {
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reactor.AddPeer(peer)
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}
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}
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// DialSeeds dials a list of seeds asynchronously in random order.
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func (sw *Switch) DialSeeds(addrBook *AddrBook, seeds []string) error {
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netAddrs, err := NewNetAddressStrings(seeds)
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if err != nil {
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return err
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}
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if addrBook != nil {
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// add seeds to `addrBook`
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ourAddrS := sw.nodeInfo.ListenAddr
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ourAddr, _ := NewNetAddressString(ourAddrS)
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for _, netAddr := range netAddrs {
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// do not add ourselves
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if netAddr.Equals(ourAddr) {
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continue
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}
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addrBook.AddAddress(netAddr, ourAddr)
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}
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addrBook.Save()
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}
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// Ensure we have a completely undeterministic PRNG. cmd.RandInt64() draws
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// from a seed that's initialized with OS entropy on process start.
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rng := rand.New(rand.NewSource(cmn.RandInt64()))
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// permute the list, dial them in random order.
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perm := rng.Perm(len(netAddrs))
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for i := 0; i < len(perm); i++ {
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go func(i int) {
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time.Sleep(time.Duration(rng.Int63n(3000)) * time.Millisecond)
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j := perm[i]
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sw.dialSeed(netAddrs[j])
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}(i)
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}
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return nil
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}
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func (sw *Switch) dialSeed(addr *NetAddress) {
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peer, err := sw.DialPeerWithAddress(addr, true)
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if err != nil {
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sw.Logger.Error("Error dialing seed", "err", err)
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} else {
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sw.Logger.Info("Connected to seed", "peer", peer)
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}
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}
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// DialPeerWithAddress dials the given peer and runs sw.addPeer if it connects successfully.
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// If `persistent == true`, the switch will always try to reconnect to this peer if the connection ever fails.
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func (sw *Switch) DialPeerWithAddress(addr *NetAddress, persistent bool) (Peer, error) {
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sw.dialing.Set(addr.IP.String(), addr)
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defer sw.dialing.Delete(addr.IP.String())
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sw.Logger.Info("Dialing peer", "address", addr)
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peer, err := newOutboundPeer(addr, sw.reactorsByCh, sw.chDescs, sw.StopPeerForError, sw.nodePrivKey, sw.peerConfig)
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if err != nil {
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sw.Logger.Error("Failed to dial peer", "address", addr, "err", err)
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return nil, err
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}
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peer.SetLogger(sw.Logger.With("peer", addr))
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if persistent {
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peer.makePersistent()
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}
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err = sw.addPeer(peer)
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if err != nil {
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sw.Logger.Error("Failed to add peer", "address", addr, "err", err)
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peer.CloseConn()
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return nil, err
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}
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sw.Logger.Info("Dialed and added peer", "address", addr, "peer", peer)
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return peer, nil
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}
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// IsDialing returns true if the switch is currently dialing the given address.
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func (sw *Switch) IsDialing(addr *NetAddress) bool {
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return sw.dialing.Has(addr.IP.String())
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}
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// Broadcast runs a go routine for each attempted send, which will block
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// trying to send for defaultSendTimeoutSeconds. Returns a channel
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// which receives success values for each attempted send (false if times out).
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// NOTE: Broadcast uses goroutines, so order of broadcast may not be preserved.
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// TODO: Something more intelligent.
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func (sw *Switch) Broadcast(chID byte, msg interface{}) chan bool {
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successChan := make(chan bool, len(sw.peers.List()))
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sw.Logger.Debug("Broadcast", "channel", chID, "msg", msg)
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for _, peer := range sw.peers.List() {
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go func(peer Peer) {
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success := peer.Send(chID, msg)
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successChan <- success
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}(peer)
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}
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return successChan
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}
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// NumPeers returns the count of outbound/inbound and outbound-dialing peers.
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func (sw *Switch) NumPeers() (outbound, inbound, dialing int) {
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peers := sw.peers.List()
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for _, peer := range peers {
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if peer.IsOutbound() {
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outbound++
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} else {
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inbound++
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}
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}
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dialing = sw.dialing.Size()
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return
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}
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// Peers returns the set of peers that are connected to the switch.
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func (sw *Switch) Peers() IPeerSet {
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return sw.peers
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}
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// StopPeerForError disconnects from a peer due to external error.
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// If the peer is persistent, it will attempt to reconnect.
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// TODO: make record depending on reason.
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func (sw *Switch) StopPeerForError(peer Peer, reason interface{}) {
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addr, _ := NewNetAddressString(peer.NodeInfo().RemoteAddr)
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sw.Logger.Error("Stopping peer for error", "peer", peer, "err", reason)
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sw.stopAndRemovePeer(peer, reason)
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if peer.IsPersistent() {
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go func() {
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sw.Logger.Info("Reconnecting to peer", "peer", peer)
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for i := 1; i < reconnectAttempts; i++ {
|
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if !sw.IsRunning() {
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return
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}
|
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|
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peer, err := sw.DialPeerWithAddress(addr, true)
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if err != nil {
|
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if i == reconnectAttempts {
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sw.Logger.Info("Error reconnecting to peer. Giving up", "tries", i, "err", err)
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return
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}
|
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sw.Logger.Info("Error reconnecting to peer. Trying again", "tries", i, "err", err)
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time.Sleep(reconnectInterval)
|
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continue
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}
|
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|
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sw.Logger.Info("Reconnected to peer", "peer", peer)
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return
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}
|
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}()
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}
|
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}
|
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|
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// StopPeerGracefully disconnects from a peer gracefully.
|
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// TODO: handle graceful disconnects.
|
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func (sw *Switch) StopPeerGracefully(peer Peer) {
|
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sw.Logger.Info("Stopping peer gracefully")
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sw.stopAndRemovePeer(peer, nil)
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}
|
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|
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func (sw *Switch) stopAndRemovePeer(peer Peer, reason interface{}) {
|
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sw.peers.Remove(peer)
|
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peer.Stop()
|
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for _, reactor := range sw.reactors {
|
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reactor.RemovePeer(peer, reason)
|
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}
|
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}
|
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|
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func (sw *Switch) listenerRoutine(l Listener) {
|
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for {
|
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inConn, ok := <-l.Connections()
|
|
if !ok {
|
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break
|
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}
|
|
|
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// 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)
|
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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
|
|
}
|
|
|
|
//------------------------------------------------------------------
|
|
// Connects switches via arbitrary net.Conn. Used 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 i'th 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 + 1; j < n; j++ {
|
|
connect(switches, i, j)
|
|
}
|
|
}
|
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|
|
return switches
|
|
}
|
|
|
|
// Connect2Switches will connect switches i and j via net.Pipe().
|
|
// Blocks until a connection 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 := netPipe()
|
|
doneCh := make(chan struct{})
|
|
go func() {
|
|
err := switchI.addPeerWithConnection(c1)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
doneCh <- struct{}{}
|
|
}()
|
|
go func() {
|
|
err := switchJ.addPeerWithConnection(c2)
|
|
if 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 {
|
|
if err := conn.Close(); err != nil {
|
|
sw.Logger.Error("Error closing connection", "err", err)
|
|
}
|
|
return err
|
|
}
|
|
peer.SetLogger(sw.Logger.With("peer", conn.RemoteAddr()))
|
|
if err = sw.addPeer(peer); err != nil {
|
|
peer.CloseConn()
|
|
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 {
|
|
if err := conn.Close(); err != nil {
|
|
sw.Logger.Error("Error closing connection", "err", err)
|
|
}
|
|
return err
|
|
}
|
|
peer.SetLogger(sw.Logger.With("peer", conn.RemoteAddr()))
|
|
if err = sw.addPeer(peer); err != nil {
|
|
peer.CloseConn()
|
|
return err
|
|
}
|
|
|
|
return nil
|
|
}
|