p2p

package
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 Go to latest Published: Jul 13, 2021 License: GPL-3.0 Imports: 37 Imported by: 13

Documentation

Overview

Package p2p implements the Ethereum p2p network protocols.

Index

Examples

Constants

View Source 
const (
	// Protocol messages belonging to eth/62
	StatusMsg          = 0x00
	NewBlockHashesMsg  = 0x01
	TxMsg              = 0x02
	GetBlockHeadersMsg = 0x03
	BlockHeadersMsg    = 0x04
	GetBlockBodiesMsg  = 0x05
	BlockBodiesMsg     = 0x06
	NewBlockMsg        = 0x07

	// Protocol messages belonging to eth/63
	GetNodeDataMsg = 0x0d
	NodeDataMsg    = 0x0e
	GetReceiptsMsg = 0x0f
	ReceiptsMsg    = 0x10
)

eth protocol message codes

Variables

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.

View Source 
var ErrShuttingDown = errors.New("shutting down")

Functions

func ExpectMsg 

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 MsgCodeString 

func MsgCodeString(code uint64) string

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.

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

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

Output:

msg: 8, 0000
msg: 5, 0101

func Send 

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 

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]

Types

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 

func (cap Cap) String() string

type Config 

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

	// 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 `toml:",omitempty"`

	// DialRatio controls the ratio of inbound to dialed connections.
	// Example: a DialRatio of 2 allows 1/2 of connections to be dialed.
	// Setting DialRatio to zero defaults it to 3.
	DialRatio int `toml:",omitempty"`

	// NoDiscovery can be used to disable the peer discovery mechanism.
	// Disabling is useful for protocol debugging (manual topology).
	NoDiscovery bool `toml:",omitempty"`

	// DiscoveryV5 specifies whether the the new topic-discovery based V5 discovery
	// protocol should be started or not.
	DiscoveryV5 bool `toml:",omitempty"`

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

	// BootstrapNodes are used to establish connectivity
	// with the rest of the network.
	BootstrapNodes []*discover.Node `toml:",omitempty"`

	// BootstrapNodesV5 are used to establish connectivity
	// with the rest of the network using the V5 discovery
	// protocol.
	BootstrapNodesV5 []*discv5.Node `toml:",omitempty"`

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

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

	// Connectivity can be restricted to certain IP networks.
	// If this option is set to a non-nil value, only hosts which match one of the
	// IP networks contained in the list are considered.
	NetRestrict *netutil.Netlist `toml:",omitempty"`

	// NodeDatabase is the path to the database containing the previously seen
	// live nodes in the network.
	NodeDatabase string `toml:",omitempty"`

	// Protocols should contain the protocols supported
	// by the server. Matching protocols are launched for
	// each peer.
	Protocols []Protocol `toml:"-"`

	// 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 `toml:",omitempty"`

	// If Dialer is set to a non-nil value, the given Dialer
	// is used to dial outbound peer connections.
	Dialer NodeDialer `toml:"-"`

	// If NoDial is true, the server will not dial any peers.
	NoDial bool `toml:",omitempty"`

	// If EnableMsgEvents is set then the server will emit PeerEvents
	// whenever a message is sent to or received from a peer
	EnableMsgEvents bool

	// Logger is a custom logger to use with the p2p.Server.
	Logger log.Logger `toml:",omitempty"`
}

Config holds Server options.

type DiscReason 

type DiscReason uint
const (
	DiscRequested DiscReason = iota
	DiscNetworkError
	DiscProtocolError
	DiscUselessPeer
	DiscTooManyPeers
	DiscAlreadyConnected
	DiscIncompatibleVersion
	DiscInvalidIdentity
	DiscQuitting
	DiscUnexpectedIdentity
	DiscSelf
	DiscReadTimeout
	DiscSubprotocolError = 0x10
)

func (DiscReason) Error 

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 

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 {
	MsgReader
	MsgWriter
}

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 NodeDialer 

type NodeDialer interface {
	Dial(*discover.Node) (net.Conn, error)
}

NodeDialer is used to connect to nodes in the network, typically by using an underlying net.Dialer but also using net.Pipe in tests

type NodeInfo 

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 

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

ID returns the node's public key.

func (*Peer) Inbound 

func (p *Peer) Inbound() bool

Inbound returns true if the peer is an inbound connection

func (*Peer) Info 

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) Log 

func (p *Peer) Log() log.Logger

func (*Peer) Name 

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 PeerEvent 

type PeerEvent struct {
	Type     PeerEventType   `json:"type"`
	Peer     discover.NodeID `json:"peer"`
	Error    string          `json:"error,omitempty"`
	Protocol string          `json:"protocol,omitempty"`
	MsgCode  *uint64         `json:"msg_code,omitempty"`
	MsgSize  *uint32         `json:"msg_size,omitempty"`
}

PeerEvent is an event emitted when peers are either added or dropped from a p2p.Server or when a message is sent or received on a peer connection

type PeerEventType 

type PeerEventType string

PeerEventType is the type of peer events emitted by a p2p.Server 

const (
	// PeerEventTypeAdd is the type of event emitted when a peer is added
	// to a p2p.Server
	PeerEventTypeAdd PeerEventType = "add"

	// PeerEventTypeDrop is the type of event emitted when a peer is
	// dropped from a p2p.Server
	PeerEventTypeDrop PeerEventType = "drop"

	// PeerEventTypeMsgSend is the type of event emitted when a
	// message is successfully sent to a peer
	PeerEventTypeMsgSend PeerEventType = "msgsend"

	// PeerEventTypeMsgRecv is the type of event emitted when a
	// message is received from a peer
	PeerEventTypeMsgRecv PeerEventType = "msgrecv"
)

type PeerFeed 

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

func (*PeerFeed) Close 

func (f *PeerFeed) Close()

func (*PeerFeed) Send 

func (f *PeerFeed) Send(e *PeerEvent)

func (*PeerFeed) Subscribe 

func (f *PeerFeed) Subscribe(ch chan<- *PeerEvent, name string)

func (*PeerFeed) Unsubscribe 

func (f *PeerFeed) Unsubscribe(ch chan<- *PeerEvent)

type PeerInfo 

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
		Inbound       bool   `json:"inbound"`
		Trusted       bool   `json:"trusted"`
		Static        bool   `json:"static"`
	} `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.
	Config

	DiscV5 *discv5.Network
	// contains filtered or unexported fields
}

Server manages all peer connections.

func (*Server) AddPeer 

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 

func (srv *Server) NodeInfo() *NodeInfo

NodeInfo 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 

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

PeersInfo returns an array of metadata objects describing connected peers.

func (*Server) RemovePeer 

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

RemovePeer disconnects from the given node

func (*Server) Self 

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

Self returns the local node's endpoint information.

func (*Server) SetupConn 

func (srv *Server) SetupConn(fd net.Conn, flags connFlag, dialDest *discover.Node) error

SetupConn runs the handshakes and attempts to add the connection as a peer. It returns when the connection has been added as a peer or the handshakes have failed.

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.

func (*Server) SubscribeEvents 

func (srv *Server) SubscribeEvents(ch chan *PeerEvent, name string)

SubscribePeers subscribes the given channel to peer events

func (*Server) UnsubscribeEvents 

func (srv *Server) UnsubscribeEvents(ch chan *PeerEvent)

type TCPDialer 

type TCPDialer struct {
	*net.Dialer
}

TCPDialer implements the NodeDialer interface by using a net.Dialer to create TCP connections to nodes in the network

func (TCPDialer) Dial 

func (t TCPDialer) Dial(dest *discover.Node) (net.Conn, error)

Dial creates a TCP connection to the node

Source Files

View all Source files

Directories

Path Synopsis
Package discover implements the Node Discovery Protocol.
 Package discover implements the Node Discovery Protocol.
Package discv5 implements the RLPx v5 Topic Discovery Protocol.
 Package discv5 implements the RLPx v5 Topic Discovery Protocol.
Package enr implements Ethereum Node Records as defined in EIP-778.
 Package enr implements Ethereum Node Records as defined in EIP-778.
Package nat provides access to common network port mapping protocols.
 Package nat provides access to common network port mapping protocols.
Package netutil contains extensions to the net package.
 Package netutil contains extensions to the net package.
Package simulations simulates p2p networks.
 Package simulations simulates p2p networks.
adapters
examples

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