go-ethereum/cmd/devp2p/internal/ethtest/protocol.go

88 lines
2.2 KiB
Go

// Copyright 2023 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package ethtest
import (
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/rlp"
)
// Unexported devp2p message codes from p2p/peer.go.
const (
handshakeMsg = 0x00
discMsg = 0x01
pingMsg = 0x02
pongMsg = 0x03
)
// Unexported devp2p protocol lengths from p2p package.
const (
baseProtoLen = 16
ethProtoLen = 17
snapProtoLen = 8
)
// Unexported handshake structure from p2p/peer.go.
type protoHandshake struct {
Version uint64
Name string
Caps []p2p.Cap
ListenPort uint64
ID []byte
Rest []rlp.RawValue `rlp:"tail"`
}
type Hello = protoHandshake
// Proto is an enum representing devp2p protocol types.
type Proto int
const (
baseProto Proto = iota
ethProto
snapProto
)
// getProto returns the protocol a certain message code is associated with
// (assuming the negotiated capabilities are exactly {eth,snap})
func getProto(code uint64) Proto {
switch {
case code < baseProtoLen:
return baseProto
case code < baseProtoLen+ethProtoLen:
return ethProto
case code < baseProtoLen+ethProtoLen+snapProtoLen:
return snapProto
default:
panic("unhandled msg code beyond last protocol")
}
}
// protoOffset will return the offset at which the specified protocol's messages
// begin.
func protoOffset(proto Proto) uint64 {
switch proto {
case baseProto:
return 0
case ethProto:
return baseProtoLen
case snapProto:
return baseProtoLen + ethProtoLen
default:
panic("unhandled protocol")
}
}