plugeth/p2p/discover/common.go
RichΛrd c1aa1db69e
p2p/discover: add config option for discv5 protocol ID (#26041)
This option is occasionally useful for advanced uses of the discv5 protocol.

Co-authored-by: Felix Lange <fjl@twurst.com>
2022-11-30 22:03:34 +01:00

91 lines
2.6 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 discover
import (
"crypto/ecdsa"
"net"
"github.com/ethereum/go-ethereum/common/mclock"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/p2p/enr"
"github.com/ethereum/go-ethereum/p2p/netutil"
)
// UDPConn is a network connection on which discovery can operate.
type UDPConn interface {
ReadFromUDP(b []byte) (n int, addr *net.UDPAddr, err error)
WriteToUDP(b []byte, addr *net.UDPAddr) (n int, err error)
Close() error
LocalAddr() net.Addr
}
type V5Config struct {
ProtocolID *[6]byte
}
// Config holds settings for the discovery listener.
type Config struct {
// These settings are required and configure the UDP listener:
PrivateKey *ecdsa.PrivateKey
// These settings are optional:
NetRestrict *netutil.Netlist // list of allowed IP networks
Bootnodes []*enode.Node // list of bootstrap nodes
Unhandled chan<- ReadPacket // unhandled packets are sent on this channel
Log log.Logger // if set, log messages go here
// V5ProtocolID configures the discv5 protocol identifier.
V5ProtocolID *[6]byte
ValidSchemes enr.IdentityScheme // allowed identity schemes
Clock mclock.Clock
}
func (cfg Config) withDefaults() Config {
if cfg.Log == nil {
cfg.Log = log.Root()
}
if cfg.ValidSchemes == nil {
cfg.ValidSchemes = enode.ValidSchemes
}
if cfg.Clock == nil {
cfg.Clock = mclock.System{}
}
return cfg
}
// ListenUDP starts listening for discovery packets on the given UDP socket.
func ListenUDP(c UDPConn, ln *enode.LocalNode, cfg Config) (*UDPv4, error) {
return ListenV4(c, ln, cfg)
}
// ReadPacket is a packet that couldn't be handled. Those packets are sent to the unhandled
// channel if configured.
type ReadPacket struct {
Data []byte
Addr *net.UDPAddr
}
func min(x, y int) int {
if x > y {
return y
}
return x
}