go-ethereum/les/enr_entry.go
Felföldi Zsolt 62d8022b51
les: fix UDP connection query (#22451)
This PR fixes multiple issues with the UDP connection pre-negotiation feature:

- the enable condition was wrong (it checked the existence of the DiscV5 struct where it wasn't initialized yet, disabling the feature even if discv5 was enabled)
- the server pool queried already connected nodes when the discovery iterators returned them again
- servers responded positively before they were synced and really willing to accept connections

Metrics are also added on the server side that count the positive and negative replies to served connection queries.
2021-03-16 12:53:54 +01:00

73 lines
2.3 KiB
Go

// Copyright 2019 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 les
import (
"github.com/ethereum/go-ethereum/core/forkid"
"github.com/ethereum/go-ethereum/p2p/dnsdisc"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/rlp"
)
// lesEntry is the "les" ENR entry. This is set for LES servers only.
type lesEntry struct {
// Ignore additional fields (for forward compatibility).
VfxVersion uint
Rest []rlp.RawValue `rlp:"tail"`
}
func (lesEntry) ENRKey() string { return "les" }
// ethEntry is the "eth" ENR entry. This is redeclared here to avoid depending on package eth.
type ethEntry struct {
ForkID forkid.ID
_ []rlp.RawValue `rlp:"tail"`
}
func (ethEntry) ENRKey() string { return "eth" }
// setupDiscovery creates the node discovery source for the eth protocol.
func (eth *LightEthereum) setupDiscovery() (enode.Iterator, error) {
it := enode.NewFairMix(0)
// Enable DNS discovery.
if len(eth.config.EthDiscoveryURLs) != 0 {
client := dnsdisc.NewClient(dnsdisc.Config{})
dns, err := client.NewIterator(eth.config.EthDiscoveryURLs...)
if err != nil {
return nil, err
}
it.AddSource(dns)
}
// Enable DHT.
if eth.udpEnabled {
it.AddSource(eth.p2pServer.DiscV5.RandomNodes())
}
forkFilter := forkid.NewFilter(eth.blockchain)
iterator := enode.Filter(it, func(n *enode.Node) bool { return nodeIsServer(forkFilter, n) })
return iterator, nil
}
// nodeIsServer checks whether n is an LES server node.
func nodeIsServer(forkFilter forkid.Filter, n *enode.Node) bool {
var les lesEntry
var eth ethEntry
return n.Load(&les) == nil && n.Load(&eth) == nil && forkFilter(eth.ForkID) == nil
}