github.1485827954.workers.dev/ethereum/go-ethereum@v1.14.3/cmd/devp2p/internal/ethtest/protocol.go (about)

     1  // Copyright 2023 The go-ethereum Authors
     2  // This file is part of go-ethereum.
     3  //
     4  // go-ethereum is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // go-ethereum is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU General Public License
    15  // along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
    16  package ethtest
    17  
    18  import (
    19  	"github.com/ethereum/go-ethereum/p2p"
    20  	"github.com/ethereum/go-ethereum/rlp"
    21  )
    22  
    23  // Unexported devp2p message codes from p2p/peer.go.
    24  const (
    25  	handshakeMsg = 0x00
    26  	discMsg      = 0x01
    27  	pingMsg      = 0x02
    28  	pongMsg      = 0x03
    29  )
    30  
    31  // Unexported devp2p protocol lengths from p2p package.
    32  const (
    33  	baseProtoLen = 16
    34  	ethProtoLen  = 17
    35  	snapProtoLen = 8
    36  )
    37  
    38  // Unexported handshake structure from p2p/peer.go.
    39  type protoHandshake struct {
    40  	Version    uint64
    41  	Name       string
    42  	Caps       []p2p.Cap
    43  	ListenPort uint64
    44  	ID         []byte
    45  	Rest       []rlp.RawValue `rlp:"tail"`
    46  }
    47  
    48  type Hello = protoHandshake
    49  
    50  // Proto is an enum representing devp2p protocol types.
    51  type Proto int
    52  
    53  const (
    54  	baseProto Proto = iota
    55  	ethProto
    56  	snapProto
    57  )
    58  
    59  // getProto returns the protocol a certain message code is associated with
    60  // (assuming the negotiated capabilities are exactly {eth,snap})
    61  func getProto(code uint64) Proto {
    62  	switch {
    63  	case code < baseProtoLen:
    64  		return baseProto
    65  	case code < baseProtoLen+ethProtoLen:
    66  		return ethProto
    67  	case code < baseProtoLen+ethProtoLen+snapProtoLen:
    68  		return snapProto
    69  	default:
    70  		panic("unhandled msg code beyond last protocol")
    71  	}
    72  }
    73  
    74  // protoOffset will return the offset at which the specified protocol's messages
    75  // begin.
    76  func protoOffset(proto Proto) uint64 {
    77  	switch proto {
    78  	case baseProto:
    79  		return 0
    80  	case ethProto:
    81  		return baseProtoLen
    82  	case snapProto:
    83  		return baseProtoLen + ethProtoLen
    84  	default:
    85  		panic("unhandled protocol")
    86  	}
    87  }