go-ethereum/les/protocol/protocol.go
2020-01-07 15:21:27 +08:00

362 lines
12 KiB
Go

// Copyright 2016 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 protocol defines all protocol related structures which will be
// used in both server side and client side.
package protocol
import (
"crypto/ecdsa"
"errors"
"fmt"
"io"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/light"
"github.com/ethereum/go-ethereum/p2p/discv5"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/rlp"
)
// Constants to match up protocol versions and messages
const (
Lpv2 = 2
Lpv3 = 3
)
// Supported versions of the les protocol (first is primary)
var (
ClientProtocolVersions = []uint{Lpv2, Lpv3}
ServerProtocolVersions = []uint{Lpv2, Lpv3}
AdvertiseProtocolVersions = []uint{Lpv2} // clients are searching for the first advertised protocol in the list
)
// Number of implemented message corresponding to different protocol versions.
var ProtocolLengths = map[uint]uint64{Lpv2: 22, Lpv3: 24}
const (
NetworkId = 1 // Default ethereum mainnet network ID
ProtocolMaxMsgSize = 10 * 1024 * 1024 // Maximum cap on the size of a protocol message
)
// les protocol message codes
const (
// Protocol messages inherited from LPV1
StatusMsg = 0x00
AnnounceMsg = 0x01
GetBlockHeadersMsg = 0x02
BlockHeadersMsg = 0x03
GetBlockBodiesMsg = 0x04
BlockBodiesMsg = 0x05
GetReceiptsMsg = 0x06
ReceiptsMsg = 0x07
GetCodeMsg = 0x0a
CodeMsg = 0x0b
// Protocol messages introduced in LPV2
GetProofsV2Msg = 0x0f
ProofsV2Msg = 0x10
GetHelperTrieProofsMsg = 0x11
HelperTrieProofsMsg = 0x12
SendTxV2Msg = 0x13
GetTxStatusMsg = 0x14
TxStatusMsg = 0x15
// Protocol messages introduced in LPV3
StopMsg = 0x16
ResumeMsg = 0x17
)
// The maxmium amount of data requested per retrieval request.
const (
MaxHeaderFetch = 192 // Amount of block headers to be fetched per retrieval request
MaxBodyFetch = 32 // Amount of block bodies to be fetched per retrieval request
MaxReceiptFetch = 128 // Amount of transaction receipts to allow fetching per request
MaxCodeFetch = 64 // Amount of contract codes to allow fetching per request
MaxProofsFetch = 64 // Amount of merkle proofs to be fetched per retrieval request
MaxHelperTrieProofsFetch = 64 // Amount of helper tries to be fetched per retrieval request
MaxTxSend = 64 // Amount of transactions to be send per request
MaxTxStatus = 256 // Amount of transactions to queried per request
)
type RequestInfo struct {
Name string
MaxCount uint64
}
var LesRequests = map[uint64]RequestInfo{
GetBlockHeadersMsg: {"GetBlockHeaders", MaxHeaderFetch},
GetBlockBodiesMsg: {"GetBlockBodies", MaxBodyFetch},
GetReceiptsMsg: {"GetReceipts", MaxReceiptFetch},
GetCodeMsg: {"GetCode", MaxCodeFetch},
GetProofsV2Msg: {"GetProofsV2", MaxProofsFetch},
GetHelperTrieProofsMsg: {"GetHelperTrieProofs", MaxHelperTrieProofsFetch},
SendTxV2Msg: {"SendTxV2", MaxTxSend},
GetTxStatusMsg: {"GetTxStatus", MaxTxStatus},
}
type ErrCode int
const (
ErrMsgTooLarge = iota
ErrDecode
ErrInvalidMsgCode
ErrProtocolVersionMismatch
ErrNetworkIdMismatch
ErrGenesisBlockMismatch
ErrNoStatusMsg
ErrExtraStatusMsg
ErrSuspendedPeer
ErrUselessPeer
ErrRequestRejected
ErrUnexpectedResponse
ErrInvalidResponse
ErrTooManyTimeouts
ErrMissingKey
)
func (e ErrCode) String() string {
return errorToString[int(e)]
}
// XXX change once legacy code is out
var errorToString = map[int]string{
ErrMsgTooLarge: "Message too long",
ErrDecode: "Invalid message",
ErrInvalidMsgCode: "Invalid message code",
ErrProtocolVersionMismatch: "Protocol version mismatch",
ErrNetworkIdMismatch: "NetworkId mismatch",
ErrGenesisBlockMismatch: "Genesis block mismatch",
ErrNoStatusMsg: "No status message",
ErrExtraStatusMsg: "Extra status message",
ErrSuspendedPeer: "Suspended peer",
ErrRequestRejected: "Request rejected",
ErrUnexpectedResponse: "Unexpected response",
ErrInvalidResponse: "Invalid response",
ErrTooManyTimeouts: "Too many request timeouts",
ErrMissingKey: "Key missing from list",
}
// HeadHeader is the a part of announcement sent by the LES server to the
// LES client when a new block is generated in the network.
//
// HeadHeader can also be used to represent the head info of peer(both server
// and client).
type HeadHeader struct {
Hash common.Hash // Hash of one particular block being announced
Number uint64 // Number of one particular block being announced
Td *big.Int // Total difficulty of one particular block being announced
}
// Announcement is a network packet sent by the LES server to the LES client
// when a new block is generated in the network or the server has protocol
// parameters that need to be updated.
type Announcement struct {
HeadHeader // The data of new arrival header
ReorgDepth uint64 // The reorg depth of new arrival header
Update KeyValueList // Updated protocol parameters
}
// SanityCheck verifies that the values are reasonable, as a DoS protection
func (a *Announcement) SanityCheck() error {
if tdlen := a.Td.BitLen(); tdlen > 100 {
return fmt.Errorf("too large block TD: bitlen %d", tdlen)
}
return nil
}
// Sign adds a signature to the block announcement by the given privKey
func (a *Announcement) Sign(privKey *ecdsa.PrivateKey) {
rlp, _ := rlp.EncodeToBytes(HeadHeader{a.Hash, a.Number, a.Td})
sig, _ := crypto.Sign(crypto.Keccak256(rlp), privKey)
a.Update = a.Update.Add("sign", sig)
}
// CheckSignature verifies if the block announcement has a valid signature
// by the given pubKey.
func (a *Announcement) CheckSignature(id enode.ID, update KeyValueMap) error {
var sig []byte
if err := update.Get("sign", &sig); err != nil {
return err
}
rlp, _ := rlp.EncodeToBytes(HeadHeader{a.Hash, a.Number, a.Td})
recPubkey, err := crypto.SigToPub(crypto.Keccak256(rlp), sig)
if err != nil {
return err
}
if id == enode.PubkeyToIDV4(recPubkey) {
return nil
}
return errors.New("wrong signature")
}
// GetBlockHeadersRequest represents a block header query sent by les client.
type GetBlockHeadersRequest struct {
Origin HashOrNumber // Block from which to retrieve headers
Amount uint64 // Maximum number of headers to retrieve
Skip uint64 // Blocks to skip between consecutive headers
Reverse bool // Query direction (false = rising towards latest, true = falling towards genesis)
}
// HashOrNumber is a combined field for specifying an origin block.
type HashOrNumber struct {
Hash common.Hash // Block hash from which to retrieve headers (excludes Number)
Number uint64 // Block hash from which to retrieve headers (excludes Hash)
}
// EncodeRLP is a specialized encoder for HashOrNumber to encode only one of the
// two contained union fields.
func (hn *HashOrNumber) EncodeRLP(w io.Writer) error {
if hn.Hash == (common.Hash{}) {
return rlp.Encode(w, hn.Number)
}
if hn.Number != 0 {
return fmt.Errorf("both origin hash (%x) and number (%d) provided", hn.Hash, hn.Number)
}
return rlp.Encode(w, hn.Hash)
}
// DecodeRLP is a specialized decoder for HashOrNumber to decode the contents
// into either a block hash or a block number.
func (hn *HashOrNumber) DecodeRLP(s *rlp.Stream) error {
_, size, _ := s.Kind()
origin, err := s.Raw()
if err == nil {
switch {
case size == 32:
err = rlp.DecodeBytes(origin, &hn.Hash)
case size <= 8:
err = rlp.DecodeBytes(origin, &hn.Number)
default:
err = fmt.Errorf("invalid input size %d for origin", size)
}
}
return err
}
// TrieProofRequest represents a state/storage trie proof query
// sent by les client.
type TrieProofRequest struct {
BlockHash common.Hash // The corresponding block hash of state
Account []byte // The address of target account, nil if it's a global state trie proof request
Key []byte // The key of target storage slot or account
FromLevel uint // The node level beyond which all trie nodes are contained in the proof
}
// CodeRequest represents a contract code query sent by les client.
type CodeRequest struct {
BlockHash common.Hash // The corresponding block hash of state
Account []byte // The address of target account
}
const (
// HelperTrieCHT is the indicator of canonical hash trie, check
// https://github.com/ethereum/devp2p/blob/master/caps/les.md#canonical-hash-trie
// for more details.
HelperTrieCHT = iota
// HelperTrieBloomTrie is the indicator of bloom trie, check
// https://github.com/ethereum/devp2p/blob/master/caps/les.md#bloombits-trie
// for more details
HelperTrieBloomTrie
// The auxiliary data type of helperTrie request which is available for
// all helperTrie request.
AuxRoot = 1
// The auxiliary data type of CHT request - corresponding block header
// which is only avaiable for CHT request.
AuxHeader = 2
)
// HelperTrieRequest represents a helper trie query sent by les client.
// HelperTrie includes: CHT and bloom trie. It's a shared structure between
// these two kinds of request.
//
// Except the helperTrie proof of requested entry will be returned, caller
// can specify more additional auxiliary data to be returned via `AuxType`.
type HelperTrieRequest struct {
Type uint // Indicator of request type, 0 represents CHT, 1 represents Bloom trie
TrieIndex uint64 // The index(section index) of requested trie
Key []byte // The list of entry keys, caller can request a batch of entries in a single request.
FromLevel uint // The node level beyond which all trie nodes are contained in the proof
AuxType uint // The type of auxiliary data requested
}
// HelperTrieResponse represents the response of corresponding helperTrie
// request. A single response contains a batch of requested proofs and
// corresponding auxiliary data.
type HelperTrieResponse struct {
Proofs light.NodeList // The container for storing all requested proofs
AuxData [][]byte // The batch of requested auxiliary data
}
// ErrResp returns an protocol error with given error code and additional
// error message.
func ErrResp(code ErrCode, format string, v ...interface{}) error {
return fmt.Errorf("%v - %v", code, fmt.Sprintf(format, v...))
}
// LesTopic constructs the discovery v5 topic for LES protocol.
func LesTopic(genesisHash common.Hash, protocolVersion uint) discv5.Topic {
var name string
switch protocolVersion {
case Lpv2:
name = "LES2"
default:
panic(nil)
}
return discv5.Topic(name + "@" + common.Bytes2Hex(genesisHash.Bytes()[0:8]))
}
type (
// RequestCost represents a cost policy of a specified request type.
RequestCost struct {
BaseCost, ReqCost uint64
}
// RequestCostTable assigns a cost estimate function to each request type
// which is a linear function of the requested amount
// (cost = BaseCost + ReqCost * amount)
RequestCostTable map[uint64]*RequestCost
// RequestCostList is a list representation of request costs which is used for
// database storage and communication through the network
RequestCostList []RequestCostListItem
RequestCostListItem struct {
MsgCode, BaseCost, ReqCost uint64
}
)
// GetMaxCost calculates the estimated cost for a given request type and amount
func (table RequestCostTable) GetMaxCost(code, amount uint64) uint64 {
costs := table[code]
return costs.BaseCost + amount*costs.ReqCost
}
// ToTable converts a cost list to a cost table
func (list RequestCostList) ToTable(protocolLength uint64) RequestCostTable {
table := make(RequestCostTable)
for _, e := range list {
if e.MsgCode < protocolLength {
table[e.MsgCode] = &RequestCost{
BaseCost: e.BaseCost,
ReqCost: e.ReqCost,
}
}
}
return table
}