73 lines
2.3 KiB
Go
73 lines
2.3 KiB
Go
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// Copyright 2019 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package les
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import (
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"github.com/ethereum/go-ethereum/core/forkid"
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"github.com/ethereum/go-ethereum/p2p/dnsdisc"
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"github.com/ethereum/go-ethereum/p2p/enode"
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"github.com/ethereum/go-ethereum/rlp"
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)
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// lesEntry is the "les" ENR entry. This is set for LES servers only.
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type lesEntry struct {
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// Ignore additional fields (for forward compatibility).
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VfxVersion uint
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Rest []rlp.RawValue `rlp:"tail"`
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}
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func (lesEntry) ENRKey() string { return "les" }
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// ethEntry is the "eth" ENR entry. This is redeclared here to avoid depending on package eth.
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type ethEntry struct {
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ForkID forkid.ID
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Tail []rlp.RawValue `rlp:"tail"`
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}
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func (ethEntry) ENRKey() string { return "eth" }
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// setupDiscovery creates the node discovery source for the eth protocol.
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func (eth *LightEthereum) setupDiscovery() (enode.Iterator, error) {
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it := enode.NewFairMix(0)
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// Enable DNS discovery.
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if len(eth.config.EthDiscoveryURLs) != 0 {
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client := dnsdisc.NewClient(dnsdisc.Config{})
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dns, err := client.NewIterator(eth.config.EthDiscoveryURLs...)
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if err != nil {
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return nil, err
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}
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it.AddSource(dns)
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}
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// Enable DHT.
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if eth.udpEnabled {
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it.AddSource(eth.p2pServer.DiscV5.RandomNodes())
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}
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forkFilter := forkid.NewFilter(eth.blockchain)
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iterator := enode.Filter(it, func(n *enode.Node) bool { return nodeIsServer(forkFilter, n) })
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return iterator, nil
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}
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// nodeIsServer checks whether n is an LES server node.
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func nodeIsServer(forkFilter forkid.Filter, n *enode.Node) bool {
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var les lesEntry
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var eth ethEntry
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return n.Load(&les) == nil && n.Load(ð) == nil && forkFilter(eth.ForkID) == nil
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}
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