forked from cerc-io/plugeth
74 lines
2.3 KiB
Go
74 lines
2.3 KiB
Go
// 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 eth
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import (
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"github.com/ethereum/go-ethereum/core"
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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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// ethEntry is the "eth" ENR entry which advertises eth protocol
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// on the discovery network.
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type ethEntry struct {
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ForkID forkid.ID // Fork identifier per EIP-2124
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// Ignore additional fields (for forward compatibility).
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Rest []rlp.RawValue `rlp:"tail"`
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}
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// ENRKey implements enr.Entry.
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func (e ethEntry) ENRKey() string {
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return "eth"
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}
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// startEthEntryUpdate starts the ENR updater loop.
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func (eth *Ethereum) startEthEntryUpdate(ln *enode.LocalNode) {
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var newHead = make(chan core.ChainHeadEvent, 10)
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sub := eth.blockchain.SubscribeChainHeadEvent(newHead)
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go func() {
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defer sub.Unsubscribe()
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for {
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select {
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case <-newHead:
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ln.Set(eth.currentEthEntry())
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case <-sub.Err():
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// Would be nice to sync with eth.Stop, but there is no
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// good way to do that.
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return
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}
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}
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}()
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}
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func (eth *Ethereum) currentEthEntry() *ethEntry {
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return ðEntry{ForkID: forkid.NewID(eth.blockchain.Config(), eth.blockchain.Genesis().Hash(),
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eth.blockchain.CurrentHeader().Number.Uint64())}
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}
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// setupDiscovery creates the node discovery source for the eth protocol.
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func (eth *Ethereum) setupDiscovery() (enode.Iterator, error) {
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if len(eth.config.DiscoveryURLs) == 0 {
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return nil, nil
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}
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client := dnsdisc.NewClient(dnsdisc.Config{})
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return client.NewIterator(eth.config.DiscoveryURLs...)
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}
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