1// Copyright 2016 The go-ethereum Authors 2// This file is part of the go-ethereum library. 3// 4// The go-ethereum library is free software: you can redistribute it and/or modify 5// it under the terms of the GNU Lesser 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// The go-ethereum library 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 Lesser General Public License for more details. 13// 14// You should have received a copy of the GNU Lesser General Public License 15// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. 16 17package misc 18 19import ( 20 "bytes" 21 "errors" 22 "math/big" 23 24 "github.com/ethereum/go-ethereum/core/state" 25 "github.com/ethereum/go-ethereum/core/types" 26 "github.com/ethereum/go-ethereum/params" 27) 28 29var ( 30 // ErrBadProDAOExtra is returned if a header doesn't support the DAO fork on a 31 // pro-fork client. 32 ErrBadProDAOExtra = errors.New("bad DAO pro-fork extra-data") 33 34 // ErrBadNoDAOExtra is returned if a header does support the DAO fork on a no- 35 // fork client. 36 ErrBadNoDAOExtra = errors.New("bad DAO no-fork extra-data") 37) 38 39// VerifyDAOHeaderExtraData validates the extra-data field of a block header to 40// ensure it conforms to DAO hard-fork rules. 41// 42// DAO hard-fork extension to the header validity: 43// a) if the node is no-fork, do not accept blocks in the [fork, fork+10) range 44// with the fork specific extra-data set 45// b) if the node is pro-fork, require blocks in the specific range to have the 46// unique extra-data set. 47func VerifyDAOHeaderExtraData(config *params.ChainConfig, header *types.Header) error { 48 // Short circuit validation if the node doesn't care about the DAO fork 49 if config.DAOForkBlock == nil { 50 return nil 51 } 52 // Make sure the block is within the fork's modified extra-data range 53 limit := new(big.Int).Add(config.DAOForkBlock, params.DAOForkExtraRange) 54 if header.Number.Cmp(config.DAOForkBlock) < 0 || header.Number.Cmp(limit) >= 0 { 55 return nil 56 } 57 // Depending on whether we support or oppose the fork, validate the extra-data contents 58 if config.DAOForkSupport { 59 if !bytes.Equal(header.Extra, params.DAOForkBlockExtra) { 60 return ErrBadProDAOExtra 61 } 62 } else { 63 if bytes.Equal(header.Extra, params.DAOForkBlockExtra) { 64 return ErrBadNoDAOExtra 65 } 66 } 67 // All ok, header has the same extra-data we expect 68 return nil 69} 70 71// ApplyDAOHardFork modifies the state database according to the DAO hard-fork 72// rules, transferring all balances of a set of DAO accounts to a single refund 73// contract. 74func ApplyDAOHardFork(statedb *state.StateDB) { 75 // Retrieve the contract to refund balances into 76 if !statedb.Exist(params.DAORefundContract) { 77 statedb.CreateAccount(params.DAORefundContract) 78 } 79 80 // Move every DAO account and extra-balance account funds into the refund contract 81 for _, addr := range params.DAODrainList() { 82 statedb.AddBalance(params.DAORefundContract, statedb.GetBalance(addr)) 83 statedb.SetBalance(addr, new(big.Int)) 84 } 85} 86