83 lines
2.5 KiB
Go
83 lines
2.5 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 discover
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import (
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"crypto/ecdsa"
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"net"
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"github.com/ethereum/go-ethereum/common/mclock"
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"github.com/ethereum/go-ethereum/log"
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"github.com/ethereum/go-ethereum/p2p/enode"
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"github.com/ethereum/go-ethereum/p2p/enr"
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"github.com/ethereum/go-ethereum/p2p/netutil"
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)
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// UDPConn is a network connection on which discovery can operate.
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type UDPConn interface {
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ReadFromUDP(b []byte) (n int, addr *net.UDPAddr, err error)
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WriteToUDP(b []byte, addr *net.UDPAddr) (n int, err error)
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Close() error
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LocalAddr() net.Addr
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}
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// Config holds settings for the discovery listener.
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type Config struct {
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// These settings are required and configure the UDP listener:
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PrivateKey *ecdsa.PrivateKey
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// These settings are optional:
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NetRestrict *netutil.Netlist // list of allowed IP networks
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Bootnodes []*enode.Node // list of bootstrap nodes
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Unhandled chan<- ReadPacket // unhandled packets are sent on this channel
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Log log.Logger // if set, log messages go here
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ValidSchemes enr.IdentityScheme // allowed identity schemes
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Clock mclock.Clock
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}
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func (cfg Config) withDefaults() Config {
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if cfg.Log == nil {
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cfg.Log = log.Root()
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}
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if cfg.ValidSchemes == nil {
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cfg.ValidSchemes = enode.ValidSchemes
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}
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if cfg.Clock == nil {
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cfg.Clock = mclock.System{}
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}
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return cfg
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}
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// ListenUDP starts listening for discovery packets on the given UDP socket.
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func ListenUDP(c UDPConn, ln *enode.LocalNode, cfg Config) (*UDPv4, error) {
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return ListenV4(c, ln, cfg)
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}
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// ReadPacket is a packet that couldn't be handled. Those packets are sent to the unhandled
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// channel if configured.
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type ReadPacket struct {
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Data []byte
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Addr *net.UDPAddr
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}
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func min(x, y int) int {
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if x > y {
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return y
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}
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return x
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}
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