v4wire

Documentation

Overview

Package v4wire implements the Discovery v4 Wire Protocol.

Index

• Constants
• Variables
• func Decode(input []byte) (Packet, Pubkey, []byte, error)
• func DecodePubkey(curve elliptic.Curve, e Pubkey) (*ecdsa.PublicKey, error)
• func Encode(priv *ecdsa.PrivateKey, req Packet) (packet, hash []byte, err error)
• func Expired(ts uint64) bool
• type ENRRequest
  • func (req *ENRRequest) Kind() byte
  • func (req *ENRRequest) Name() string
• type ENRResponse
  • func (req *ENRResponse) Kind() byte
  • func (req *ENRResponse) Name() string
• type Endpoint
  • func NewEndpoint(addr *net.UDPAddr, tcpPort uint16) Endpoint
• type Findnode
  • func (req *Findnode) Kind() byte
  • func (req *Findnode) Name() string
• type Neighbors
  • func (req *Neighbors) Kind() byte
  • func (req *Neighbors) Name() string
• type Node
• type Packet
• type Ping
  • func (req *Ping) Kind() byte
  • func (req *Ping) Name() string
• type Pong
  • func (req *Pong) Kind() byte
  • func (req *Pong) Name() string
• type Pubkey
  • func EncodePubkey(key *ecdsa.PublicKey) Pubkey
  • func (e Pubkey) ID() enode.ID

Constants

const (
	PingPacket = iota + 1 // zero is 'reserved'
	PongPacket
	FindnodePacket
	NeighborsPacket
	ENRRequestPacket
	ENRResponsePacket
)

RPC packet types 定义了六种包类型

const MaxNeighbors = 12

This number is the maximum number of neighbor nodes in a Neighbors packet.

Variables

var (
	ErrPacketTooSmall = errors.New("too small")
	ErrBadHash        = errors.New("bad hash")
	ErrBadPoint       = errors.New("invalid curve point")
)

Functions

func Decode

func Decode(input []byte) (Packet, Pubkey, []byte, error)

Decode reads a discovery v4 packet. 输入v4数据包的字节数组,解码出来数据包对象和远程节点公钥 数据包的结构 32字节哈希 65字节签名 其余数据 其余数据的第一个字节保存了包类型 返回包对象,远程节点的公钥,包中签名和数据整体的哈希,错误

func DecodePubkey

func DecodePubkey(curve elliptic.Curve, e Pubkey) (*ecdsa.PublicKey, error)

DecodePubkey reads an encoded secp256k1 public key. 输入曲线和64字节数组解码出来公钥对象

func Encode

func Encode(priv *ecdsa.PrivateKey, req Packet) (packet, hash []byte, err error)

Encode encodes a discovery packet. 构造数据包的字节数组,返回的哈希是签名和数据的哈希,就是包字节数组的最开始部分 packet = packet-header || packet-data packet-header = hash || signature || packet-type hash = keccak256(signature || packet-type || packet-data) signature = sign(packet-type || packet-data) hash长度32字节,signature长度65字节 1. 留空97字节,写入一字节类型 2. 对数据包进行编码写入bytes.Buffer 3. 对编码计算哈希然后签名填入前面留空的后65字节 4. 对签名和编码计算哈希,填入最开始32字节

func Expired

func Expired(ts uint64) bool

Expired checks whether the given UNIX time stamp is in the past. 判断输入的时间戳是不是早于现在的时间 返回true也就是说明输入的时间过期了

Types

type ENRRequest

type ENRRequest struct {
	Expiration uint64
	// Ignore additional fields (for forward compatibility).
	Rest []rlp.RawValue `rlp:"tail"`
}

enrRequest queries for the remote node's record.

func (*ENRRequest) Kind

func (req *ENRRequest) Kind() byte

func (*ENRRequest) Name

func (req *ENRRequest) Name() string

type ENRResponse

type ENRResponse struct {
	// 响应的ENRRequest包的哈希
	ReplyTok []byte // Hash of the enrRequest packet.
	Record   enr.Record
	// Ignore additional fields (for forward compatibility).
	Rest []rlp.RawValue `rlp:"tail"`
}

enrResponse is the reply to enrRequest.

func (*ENRResponse) Kind

func (req *ENRResponse) Kind() byte

func (*ENRResponse) Name

func (req *ENRResponse) Name() string

type Endpoint

type Endpoint struct {
	IP  net.IP // len 4 for IPv4 or 16 for IPv6
	UDP uint16 // for discovery protocol
	TCP uint16 // for RLPx protocol
}

Endpoint represents a network endpoint. 一个网络端点,包括对方的ip,UDP端口,TCP端口

func NewEndpoint

func NewEndpoint(addr *net.UDPAddr, tcpPort uint16) Endpoint

NewEndpoint creates an endpoint.

type Findnode

type Findnode struct {
	// 要查询与Target最近的节点
	Target     Pubkey
	Expiration uint64
	// Ignore additional fields (for forward compatibility).
	Rest []rlp.RawValue `rlp:"tail"`
}

Findnode is a query for nodes close to the given target.

func (*Findnode) Kind

func (req *Findnode) Kind() byte

func (*Findnode) Name

func (req *Findnode) Name() string

type Neighbors

type Neighbors struct {
	// 查询到的结果
	Nodes      []Node
	Expiration uint64
	// Ignore additional fields (for forward compatibility).
	Rest []rlp.RawValue `rlp:"tail"`
}

Neighbors is the reply to findnode.

func (*Neighbors) Kind

func (req *Neighbors) Kind() byte

func (*Neighbors) Name

func (req *Neighbors) Name() string

type Node

type Node struct {
	IP  net.IP // len 4 for IPv4 or 16 for IPv6
	UDP uint16 // for discovery protocol
	TCP uint16 // for RLPx protocol
	ID  Pubkey
}

Node represents information about a node. 一个节点信息 相比于Endpoint,增加了对方的公钥所以就成为了一个节点

type Packet

type Packet interface {
	// packet name and type for logging purposes.
	Name() string
	Kind() byte
}

v4版本的Packet对象

type Ping

type Ping struct {
	// 协议版本，就是4
	Version uint
	// ping包的发送方和接收方的ip、端口信息
	From, To Endpoint
	// ping包的过期时间
	Expiration uint64
	// 本地节点的记录序号
	ENRSeq uint64 `rlp:"optional"` // Sequence number of local record, added by EIP-868.

	// Ignore additional fields (for forward compatibility).
	Rest []rlp.RawValue `rlp:"tail"`
}

RPC request structures 以下定义了六种包的具体数据结构

func (*Ping) Kind

func (req *Ping) Kind() byte

func (*Ping) Name

func (req *Ping) Name() string

type Pong

type Pong struct {
	// This field should mirror the UDP envelope address
	// of the ping packet, which provides a way to discover the
	// the external address (after NAT).
	// Pong包返回的目的地址
	To Endpoint
	// 这个pong包对应的ping包的哈希
	ReplyTok   []byte // This contains the hash of the ping packet.
	Expiration uint64 // Absolute timestamp at which the packet becomes invalid.
	ENRSeq     uint64 `rlp:"optional"` // Sequence number of local record, added by EIP-868.

	// Ignore additional fields (for forward compatibility).
	Rest []rlp.RawValue `rlp:"tail"`
}

Pong is the reply to ping.

func (*Pong) Kind

func (req *Pong) Kind() byte

func (*Pong) Name

func (req *Pong) Name() string

type Pubkey

type Pubkey [64]byte

Pubkey represents an encoded 64-byte secp256k1 public key.

func EncodePubkey

func EncodePubkey(key *ecdsa.PublicKey) Pubkey

EncodePubkey encodes a secp256k1 public key. 编码公钥对象到64字节数组,去掉固定前缀04

func (Pubkey) ID

func (e Pubkey) ID() enode.ID

ID returns the node ID corresponding to the public key. 将64字节公钥计算哈希得到节点ID