p2p

Documentation

Overview

Package p2p implements the Ethereum 2.0 networking specification.

Canonical spec reference: https://github.com/ethereum/eth2.0-specs/blob/dev/specs/networking/p2p-interface.md

Prysm specific implementation design docs

• Networking Design Doc: https://docs.google.com/document/d/1VyhobQRkEjEkEPxmmdWvaHfKWn0j6dEae_wLZlrFtfU/view

This package is heavily utilizes the libp2p go implementation by Protocol Labs.

Index

• Variables
• func MakePeer(addr string) (*peerstore.PeerInfo, error)
• type Broadcaster
• type Config
• type ConnectionHandler
• type EncodingProvider
• type Listener
• type P2P
• type PeerManager
• type PubSubProvider
• type Sender
• type Service
  • func NewService(cfg *Config) (*Service, error)
  • func (s *Service) AddConnectionHandler(reqFunc func(ctx context.Context, id peer.ID) error)
  • func (s *Service) AddDisconnectionHandler(handler func(ctx context.Context, id peer.ID) error)
  • func (s *Service) Broadcast(ctx context.Context, msg proto.Message) error
  • func (s *Service) Disconnect(pid peer.ID) error
  • func (s *Service) Encoding() encoder.NetworkEncoding
  • func (s *Service) InfoHandler(w http.ResponseWriter, _ *http.Request)
  • func (s *Service) PeerID() peer.ID
  • func (s *Service) PubSub() *pubsub.PubSub
  • func (s *Service) Send(ctx context.Context, message interface{}, pid peer.ID) (network.Stream, error)
  • func (s *Service) SetStreamHandler(topic string, handler network.StreamHandler)
  • func (s *Service) Start()
  • func (s *Service) Started() bool
  • func (s *Service) Status() error
  • func (s *Service) Stop() error
• type SetStreamHandler

Variables

var ErrMessageNotMapped = errors.New("message type is not mapped to a PubSub topic")

ErrMessageNotMapped occurs on a Broadcast attempt when a message has not been defined in the GossipTypeMapping.

var GossipTopicMappings = map[string]proto.Message{
	"/eth2/beacon_block":       &pb.BeaconBlock{},
	"/eth2/beacon_attestation": &pb.Attestation{},
	"/eth2/voluntary_exit":     &pb.VoluntaryExit{},
	"/eth2/proposer_slashing":  &pb.ProposerSlashing{},
	"/eth2/attester_slashing":  &pb.AttesterSlashing{},
}

GossipTopicMappings represent the protocol ID to protobuf message type map for easy lookup.

var GossipTypeMapping = make(map[reflect.Type]string)

GossipTypeMapping is the inverse of GossipTopicMappings so that an arbitrary protobuf message can be mapped to a protocol ID string.

var RPCTopicMappings = map[string]interface{}{
	"/eth2/beacon_chain/req/status/1":                 &p2ppb.Status{},
	"/eth2/beacon_chain/req/goodbye/1":                new(uint64),
	"/eth2/beacon_chain/req/beacon_blocks_by_range/1": &p2ppb.BeaconBlocksByRangeRequest{},
	"/eth2/beacon_chain/req/beacon_blocks_by_root/1":  [][32]byte{},
}

RPCTopicMappings represent the protocol ID to protobuf message type map for easy lookup. These mappings should be used for outbound sending only. Peers may respond with a different message type as defined by the p2p protocol.

var RPCTypeMapping = make(map[reflect.Type]string)

RPCTypeMapping is the inverse of RPCTopicMappings so that an arbitrary protobuf message can be mapped to a protocol ID string.

Functions

func MakePeer

func MakePeer(addr string) (*peerstore.PeerInfo, error)

MakePeer from multiaddress string.

Types

type Broadcaster

type Broadcaster interface {
	Broadcast(context.Context, proto.Message) error
}

Broadcaster broadcasts messages to peers over the p2p pubsub protocol.

type Config

type Config struct {
	NoDiscovery           bool
	StaticPeers           []string
	BootstrapNodeAddr     []string
	KademliaBootStrapAddr []string
	Discv5BootStrapAddr   []string
	RelayNodeAddr         string
	HostAddress           string
	PrivateKey            string
	DataDir               string
	TCPPort               uint
	UDPPort               uint
	MaxPeers              uint
	WhitelistCIDR         string
	EnableUPnP            bool
	Encoding              string
}

Config for the p2p service. These parameters are set from application level flags to initialize the p2p service.

type ConnectionHandler

type ConnectionHandler interface {
	AddConnectionHandler(f func(ctx context.Context, id peer.ID) error)
	AddDisconnectionHandler(f func(ctx context.Context, id peer.ID) error)
}

ConnectionHandler configures p2p to handle connections with a peer.

type EncodingProvider

type EncodingProvider interface {
	Encoding() encoder.NetworkEncoding
}

EncodingProvider provides p2p network encoding.

type Listener

type Listener interface {
	Self() *enode.Node
	Close()
	Lookup(enode.ID) []*enode.Node
	ReadRandomNodes([]*enode.Node) int
	Resolve(*enode.Node) *enode.Node
	LookupRandom() []*enode.Node
	Ping(*enode.Node) error
	RequestENR(*enode.Node) (*enode.Node, error)
}

Listener defines the discovery V5 network interface that is used to communicate with other peers.

type P2P

type P2P interface {
	Broadcaster
	SetStreamHandler
	EncodingProvider
	PubSubProvider
	PeerManager
	Sender
	ConnectionHandler
}

P2P represents the full p2p interface composed of all of the sub-interfaces.

type PeerManager

type PeerManager interface {
	Disconnect(peer.ID) error
	PeerID() peer.ID
}

PeerManager abstracts some peer management methods from libp2p.

type PubSubProvider

type PubSubProvider interface {
	PubSub() *pubsub.PubSub
}

PubSubProvider provides the p2p pubsub protocol.

type Sender

type Sender interface {
	Send(context.Context, interface{}, peer.ID) (network.Stream, error)
}

Sender abstracts the sending functionality from libp2p.

type Service

type Service struct {
	// contains filtered or unexported fields
}

Service for managing peer to peer (p2p) networking.

func NewService

func NewService(cfg *Config) (*Service, error)

NewService initializes a new p2p service compatible with shared.Service interface. No connections are made until the Start function is called during the service registry startup.

func (*Service) AddConnectionHandler

func (s *Service) AddConnectionHandler(reqFunc func(ctx context.Context, id peer.ID) error)

AddConnectionHandler adds a callback function which handles the connection with a newly added peer. It performs a handshake with that peer by sending a hello request and validating the response from the peer.

func (*Service) AddDisconnectionHandler

func (s *Service) AddDisconnectionHandler(handler func(ctx context.Context, id peer.ID) error)

AddDisconnectionHandler ensures that previously disconnected peers aren't dialed again. Due to either their ports being closed, nodes are no longer active,etc. This also calls the handler responsible for maintaining other parts of the sync or p2p system.

func (*Service) Broadcast

func (s *Service) Broadcast(ctx context.Context, msg proto.Message) error

Broadcast a message to the p2p network.

func (*Service) Disconnect

func (s *Service) Disconnect(pid peer.ID) error

Disconnect from a peer.

func (*Service) Encoding

func (s *Service) Encoding() encoder.NetworkEncoding

Encoding returns the configured networking encoding.

func (*Service) InfoHandler

func (s *Service) InfoHandler(w http.ResponseWriter, _ *http.Request)

InfoHandler is a handler to serve /p2p page in metrics.

func (*Service) PeerID

func (s *Service) PeerID() peer.ID

PeerID returns the Peer ID of the local peer.

func (*Service) PubSub

func (s *Service) PubSub() *pubsub.PubSub

PubSub returns the p2p pubsub framework.

func (*Service) Send

func (s *Service) Send(ctx context.Context, message interface{}, pid peer.ID) (network.Stream, error)

Send a message to a specific peer. The returned stream may be used for reading, but has been closed for writing.

func (*Service) SetStreamHandler

func (s *Service) SetStreamHandler(topic string, handler network.StreamHandler)

SetStreamHandler sets the protocol handler on the p2p host multiplexer. This method is a pass through to libp2pcore.Host.SetStreamHandler.

func (*Service) Start

func (s *Service) Start()

Start the p2p service.

func (*Service) Started

func (s *Service) Started() bool

Started returns true if the p2p service has successfully started.

func (*Service) Status

func (s *Service) Status() error

Status of the p2p service. Will return an error if the service is considered unhealthy to indicate that this node should not serve traffic until the issue has been resolved.

func (*Service) Stop

func (s *Service) Stop() error

Stop the p2p service and terminate all peer connections.

type SetStreamHandler

type SetStreamHandler interface {
	SetStreamHandler(topic string, handler network.StreamHandler)
}

SetStreamHandler configures p2p to handle streams of a certain topic ID.