6a9158bb1b
Node discovery periodically revalidates the nodes in its table by sending PING, checking if they are still alive. I recently noticed some issues with the implementation of this process, which can cause strange results such as nodes dropping unexpectedly, certain nodes not getting revalidated often enough, and bad results being returned to incoming FINDNODE queries. In this change, the revalidation process is improved with the following logic: - We maintain two 'revalidation lists' containing the table nodes, named 'fast' and 'slow'. - The process chooses random nodes from each list on a randomized interval, the interval being faster for the 'fast' list, and performs revalidation for the chosen node. - Whenever a node is newly inserted into the table, it goes into the 'fast' list. Once validation passes, it transfers to the 'slow' list. If a request fails, or the node changes endpoint, it transfers back into 'fast'. - livenessChecks is incremented by one for successful checks. Unlike the old implementation, we will not drop the node on the first failing check. We instead quickly decay the livenessChecks give it another chance. - Order of nodes in bucket doesn't matter anymore. I am also adding a debug API endpoint to dump the node table content. Co-authored-by: Martin HS <martin@swende.se>
108 lines
2.9 KiB
Go
108 lines
2.9 KiB
Go
// Copyright 2015 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package discover
|
|
|
|
import (
|
|
"crypto/ecdsa"
|
|
"crypto/elliptic"
|
|
"errors"
|
|
"math/big"
|
|
"net"
|
|
"time"
|
|
|
|
"github.com/ethereum/go-ethereum/common/math"
|
|
"github.com/ethereum/go-ethereum/crypto"
|
|
"github.com/ethereum/go-ethereum/p2p/enode"
|
|
)
|
|
|
|
type BucketNode struct {
|
|
Node *enode.Node `json:"node"`
|
|
AddedToTable time.Time `json:"addedToTable"`
|
|
AddedToBucket time.Time `json:"addedToBucket"`
|
|
Checks int `json:"checks"`
|
|
Live bool `json:"live"`
|
|
}
|
|
|
|
// node represents a host on the network.
|
|
// The fields of Node may not be modified.
|
|
type node struct {
|
|
*enode.Node
|
|
addedToTable time.Time // first time node was added to bucket or replacement list
|
|
addedToBucket time.Time // time it was added in the actual bucket
|
|
livenessChecks uint // how often liveness was checked
|
|
isValidatedLive bool // true if existence of node is considered validated right now
|
|
}
|
|
|
|
type encPubkey [64]byte
|
|
|
|
func encodePubkey(key *ecdsa.PublicKey) encPubkey {
|
|
var e encPubkey
|
|
math.ReadBits(key.X, e[:len(e)/2])
|
|
math.ReadBits(key.Y, e[len(e)/2:])
|
|
return e
|
|
}
|
|
|
|
func decodePubkey(curve elliptic.Curve, e []byte) (*ecdsa.PublicKey, error) {
|
|
if len(e) != len(encPubkey{}) {
|
|
return nil, errors.New("wrong size public key data")
|
|
}
|
|
p := &ecdsa.PublicKey{Curve: curve, X: new(big.Int), Y: new(big.Int)}
|
|
half := len(e) / 2
|
|
p.X.SetBytes(e[:half])
|
|
p.Y.SetBytes(e[half:])
|
|
if !p.Curve.IsOnCurve(p.X, p.Y) {
|
|
return nil, errors.New("invalid curve point")
|
|
}
|
|
return p, nil
|
|
}
|
|
|
|
func (e encPubkey) id() enode.ID {
|
|
return enode.ID(crypto.Keccak256Hash(e[:]))
|
|
}
|
|
|
|
func wrapNode(n *enode.Node) *node {
|
|
return &node{Node: n}
|
|
}
|
|
|
|
func wrapNodes(ns []*enode.Node) []*node {
|
|
result := make([]*node, len(ns))
|
|
for i, n := range ns {
|
|
result[i] = wrapNode(n)
|
|
}
|
|
return result
|
|
}
|
|
|
|
func unwrapNode(n *node) *enode.Node {
|
|
return n.Node
|
|
}
|
|
|
|
func unwrapNodes(ns []*node) []*enode.Node {
|
|
result := make([]*enode.Node, len(ns))
|
|
for i, n := range ns {
|
|
result[i] = unwrapNode(n)
|
|
}
|
|
return result
|
|
}
|
|
|
|
func (n *node) addr() *net.UDPAddr {
|
|
return &net.UDPAddr{IP: n.IP(), Port: n.UDP()}
|
|
}
|
|
|
|
func (n *node) String() string {
|
|
return n.Node.String()
|
|
}
|