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Published: Oct 17, 2017 License: GPL-3.0 Imports: 33 Imported by: 0



Package p2p implements the Ethereum p2p network protocols.




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const (
	PERMISSIONED_CONFIG = "permissioned-nodes.json"


View Source
var ErrPipeClosed = errors.New("p2p: read or write on closed message pipe")

ErrPipeClosed is returned from pipe operations after the pipe has been closed.


func ExpectMsg added in v0.9.20

func ExpectMsg(r MsgReader, code uint64, content interface{}) error

ExpectMsg reads a message from r and verifies that its code and encoded RLP content match the provided values. If content is nil, the payload is discarded and not verified.

func MsgPipe

func MsgPipe() (*MsgPipeRW, *MsgPipeRW)

MsgPipe creates a message pipe. Reads on one end are matched with writes on the other. The pipe is full-duplex, both ends implement MsgReadWriter.

rw1, rw2 := MsgPipe()
go func() {
	Send(rw1, 8, [][]byte{{0, 0}})
	Send(rw1, 5, [][]byte{{1, 1}})

for {
	msg, err := rw2.ReadMsg()
	if err != nil {
	var data [][]byte
	fmt.Printf("msg: %d, %x\n", msg.Code, data[0])

msg: 8, 0000
msg: 5, 0101

func Send added in v0.9.20

func Send(w MsgWriter, msgcode uint64, data interface{}) error

Send writes an RLP-encoded message with the given code. data should encode as an RLP list.

func SendItems added in v0.9.20

func SendItems(w MsgWriter, msgcode uint64, elems ...interface{}) error

SendItems writes an RLP with the given code and data elements. For a call such as:

SendItems(w, code, e1, e2, e3)

the message payload will be an RLP list containing the items:

[e1, e2, e3]


type Cap

type Cap struct {
	Name    string
	Version uint

Cap is the structure of a peer capability.

func (Cap) RlpData

func (cap Cap) RlpData() interface{}

func (Cap) String added in v0.8.5

func (cap Cap) String() string

type Config added in v1.0.2

type Config struct {
	// This field must be set to a valid secp256k1 private key.
	PrivateKey *ecdsa.PrivateKey

	// MaxPeers is the maximum number of peers that can be
	// connected. It must be greater than zero.
	MaxPeers int

	// MaxPendingPeers is the maximum number of peers that can be pending in the
	// handshake phase, counted separately for inbound and outbound connections.
	// Zero defaults to preset values.
	MaxPendingPeers int

	// Discovery specifies whether the peer discovery mechanism should be started
	// or not. Disabling is usually useful for protocol debugging (manual topology).
	Discovery bool

	// Name sets the node name of this server.
	// Use common.MakeName to create a name that follows existing conventions.
	Name string

	// Bootstrap nodes are used to establish connectivity
	// with the rest of the network.
	BootstrapNodes []*discover.Node

	// Static nodes are used as pre-configured connections which are always
	// maintained and re-connected on disconnects.
	StaticNodes []*discover.Node

	// Trusted nodes are used as pre-configured connections which are always
	// allowed to connect, even above the peer limit.
	TrustedNodes []*discover.Node

	// NodeDatabase is the path to the database containing the previously seen
	// live nodes in the network.
	NodeDatabase string

	// Protocols should contain the protocols supported
	// by the server. Matching protocols are launched for
	// each peer.
	Protocols []Protocol

	// If ListenAddr is set to a non-nil address, the server
	// will listen for incoming connections.
	// If the port is zero, the operating system will pick a port. The
	// ListenAddr field will be updated with the actual address when
	// the server is started.
	ListenAddr string

	// If set to a non-nil value, the given NAT port mapper
	// is used to make the listening port available to the
	// Internet.
	NAT nat.Interface

	// If Dialer is set to a non-nil value, the given Dialer
	// is used to dial outbound peer connections.
	Dialer *net.Dialer

	// If NoDial is true, the server will not dial any peers.
	NoDial bool

	//Enables Permissioning
	EnableNodePermission bool

	DataDir string

Config holds Server options.

type DiscReason

type DiscReason uint
const (
	DiscRequested DiscReason = iota
	DiscSubprotocolError = 0x10

func (DiscReason) Error added in v0.9.20

func (d DiscReason) Error() string

func (DiscReason) String

func (d DiscReason) String() string

type Msg

type Msg struct {
	Code       uint64
	Size       uint32 // size of the paylod
	Payload    io.Reader
	ReceivedAt time.Time

Msg defines the structure of a p2p message.

Note that a Msg can only be sent once since the Payload reader is consumed during sending. It is not possible to create a Msg and send it any number of times. If you want to reuse an encoded structure, encode the payload into a byte array and create a separate Msg with a bytes.Reader as Payload for each send.

func (Msg) Decode

func (msg Msg) Decode(val interface{}) error

Decode parses the RLP content of a message into the given value, which must be a pointer.

For the decoding rules, please see package rlp.

func (Msg) Discard

func (msg Msg) Discard() error

Discard reads any remaining payload data into a black hole.

func (Msg) String added in v0.8.5

func (msg Msg) String() string

type MsgPipeRW

type MsgPipeRW struct {
	// contains filtered or unexported fields

MsgPipeRW is an endpoint of a MsgReadWriter pipe.

func (*MsgPipeRW) Close

func (p *MsgPipeRW) Close() error

Close unblocks any pending ReadMsg and WriteMsg calls on both ends of the pipe. They will return ErrPipeClosed. Close also interrupts any reads from a message payload.

func (*MsgPipeRW) ReadMsg

func (p *MsgPipeRW) ReadMsg() (Msg, error)

ReadMsg returns a message sent on the other end of the pipe.

func (*MsgPipeRW) WriteMsg

func (p *MsgPipeRW) WriteMsg(msg Msg) error

WriteMsg sends a messsage on the pipe. It blocks until the receiver has consumed the message payload.

type MsgReadWriter

type MsgReadWriter interface {

MsgReadWriter provides reading and writing of encoded messages. Implementations should ensure that ReadMsg and WriteMsg can be called simultaneously from multiple goroutines.

type MsgReader

type MsgReader interface {
	ReadMsg() (Msg, error)

type MsgWriter

type MsgWriter interface {
	// WriteMsg sends a message. It will block until the message's
	// Payload has been consumed by the other end.
	// Note that messages can be sent only once because their
	// payload reader is drained.
	WriteMsg(Msg) error

type NodeInfo added in v1.0.2

type NodeInfo struct {
	ID    string `json:"id"`    // Unique node identifier (also the encryption key)
	Name  string `json:"name"`  // Name of the node, including client type, version, OS, custom data
	Enode string `json:"enode"` // Enode URL for adding this peer from remote peers
	IP    string `json:"ip"`    // IP address of the node
	Ports struct {
		Discovery int `json:"discovery"` // UDP listening port for discovery protocol
		Listener  int `json:"listener"`  // TCP listening port for RLPx
	} `json:"ports"`
	ListenAddr string                 `json:"listenAddr"`
	Protocols  map[string]interface{} `json:"protocols"`

NodeInfo represents a short summary of the information known about the host.

type Peer

type Peer struct {
	// contains filtered or unexported fields

Peer represents a connected remote node.

func NewPeer

func NewPeer(id discover.NodeID, name string, caps []Cap) *Peer

NewPeer returns a peer for testing purposes.

func (*Peer) Caps

func (p *Peer) Caps() []Cap

Caps returns the capabilities (supported subprotocols) of the remote peer.

func (*Peer) Disconnect

func (p *Peer) Disconnect(reason DiscReason)

Disconnect terminates the peer connection with the given reason. It returns immediately and does not wait until the connection is closed.

func (*Peer) ID added in v0.8.5

func (p *Peer) ID() discover.NodeID

ID returns the node's public key.

func (*Peer) Info added in v1.0.2

func (p *Peer) Info() *PeerInfo

Info gathers and returns a collection of metadata known about a peer.

func (*Peer) LocalAddr

func (p *Peer) LocalAddr() net.Addr

LocalAddr returns the local address of the network connection.

func (*Peer) Name added in v0.8.5

func (p *Peer) Name() string

Name returns the node name that the remote node advertised.

func (*Peer) RemoteAddr

func (p *Peer) RemoteAddr() net.Addr

RemoteAddr returns the remote address of the network connection.

func (*Peer) String

func (p *Peer) String() string

String implements fmt.Stringer.

type PeerInfo added in v1.0.2

type PeerInfo struct {
	ID      string   `json:"id"`   // Unique node identifier (also the encryption key)
	Name    string   `json:"name"` // Name of the node, including client type, version, OS, custom data
	Caps    []string `json:"caps"` // Sum-protocols advertised by this particular peer
	Network struct {
		LocalAddress  string `json:"localAddress"`  // Local endpoint of the TCP data connection
		RemoteAddress string `json:"remoteAddress"` // Remote endpoint of the TCP data connection
	} `json:"network"`
	Protocols map[string]interface{} `json:"protocols"` // Sub-protocol specific metadata fields

PeerInfo represents a short summary of the information known about a connected peer. Sub-protocol independent fields are contained and initialized here, with protocol specifics delegated to all connected sub-protocols.

type Protocol

type Protocol struct {
	// Name should contain the official protocol name,
	// often a three-letter word.
	Name string

	// Version should contain the version number of the protocol.
	Version uint

	// Length should contain the number of message codes used
	// by the protocol.
	Length uint64

	// Run is called in a new groutine when the protocol has been
	// negotiated with a peer. It should read and write messages from
	// rw. The Payload for each message must be fully consumed.
	// The peer connection is closed when Start returns. It should return
	// any protocol-level error (such as an I/O error) that is
	// encountered.
	Run func(peer *Peer, rw MsgReadWriter) error

	// NodeInfo is an optional helper method to retrieve protocol specific metadata
	// about the host node.
	NodeInfo func() interface{}

	// PeerInfo is an optional helper method to retrieve protocol specific metadata
	// about a certain peer in the network. If an info retrieval function is set,
	// but returns nil, it is assumed that the protocol handshake is still running.
	PeerInfo func(id discover.NodeID) interface{}

Protocol represents a P2P subprotocol implementation.

type Server

type Server struct {
	// Config fields may not be modified while the server is running.
	// contains filtered or unexported fields

Server manages all peer connections.

func (*Server) AddPeer added in v0.9.20

func (srv *Server) AddPeer(node *discover.Node)

AddPeer connects to the given node and maintains the connection until the server is shut down. If the connection fails for any reason, the server will attempt to reconnect the peer.

func (*Server) NodeInfo added in v1.0.2

func (srv *Server) NodeInfo() *NodeInfo

Info gathers and returns a collection of metadata known about the host.

func (*Server) PeerCount

func (srv *Server) PeerCount() int

PeerCount returns the number of connected peers.

func (*Server) Peers

func (srv *Server) Peers() []*Peer

Peers returns all connected peers.

func (*Server) PeersInfo added in v1.0.2

func (srv *Server) PeersInfo() []*PeerInfo

PeersInfo returns an array of metadata objects describing connected peers.

func (*Server) RemovePeer added in v1.0.2

func (srv *Server) RemovePeer(node *discover.Node)

RemovePeer disconnects from the given node

func (*Server) Self added in v0.9.20

func (srv *Server) Self() *discover.Node

Self returns the local node's endpoint information.

func (*Server) Start

func (srv *Server) Start() (err error)

Start starts running the server. Servers can not be re-used after stopping.

func (*Server) Stop

func (srv *Server) Stop()

Stop terminates the server and all active peer connections. It blocks until all active connections have been closed.


Path Synopsis
Package discover implements the Node Discovery Protocol.
Package discover implements the Node Discovery Protocol.
Package nat provides access to common network port mapping protocols.
Package nat provides access to common network port mapping protocols.

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