github.com/ethereum/go-ethereum@v1.14.3/consensus/misc/dao.go (about) 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 17 package misc 18 19 import ( 20 "bytes" 21 "errors" 22 "math/big" 23 24 "github.com/ethereum/go-ethereum/core/state" 25 "github.com/ethereum/go-ethereum/core/tracing" 26 "github.com/ethereum/go-ethereum/core/types" 27 "github.com/ethereum/go-ethereum/params" 28 "github.com/holiman/uint256" 29 ) 30 31 var ( 32 // ErrBadProDAOExtra is returned if a header doesn't support the DAO fork on a 33 // pro-fork client. 34 ErrBadProDAOExtra = errors.New("bad DAO pro-fork extra-data") 35 36 // ErrBadNoDAOExtra is returned if a header does support the DAO fork on a no- 37 // fork client. 38 ErrBadNoDAOExtra = errors.New("bad DAO no-fork extra-data") 39 ) 40 41 // VerifyDAOHeaderExtraData validates the extra-data field of a block header to 42 // ensure it conforms to DAO hard-fork rules. 43 // 44 // DAO hard-fork extension to the header validity: 45 // 46 // - if the node is no-fork, do not accept blocks in the [fork, fork+10) range 47 // with the fork specific extra-data set. 48 // - if the node is pro-fork, require blocks in the specific range to have the 49 // unique extra-data set. 50 func VerifyDAOHeaderExtraData(config *params.ChainConfig, header *types.Header) error { 51 // Short circuit validation if the node doesn't care about the DAO fork 52 if config.DAOForkBlock == nil { 53 return nil 54 } 55 // Make sure the block is within the fork's modified extra-data range 56 limit := new(big.Int).Add(config.DAOForkBlock, params.DAOForkExtraRange) 57 if header.Number.Cmp(config.DAOForkBlock) < 0 || header.Number.Cmp(limit) >= 0 { 58 return nil 59 } 60 // Depending on whether we support or oppose the fork, validate the extra-data contents 61 if config.DAOForkSupport { 62 if !bytes.Equal(header.Extra, params.DAOForkBlockExtra) { 63 return ErrBadProDAOExtra 64 } 65 } else { 66 if bytes.Equal(header.Extra, params.DAOForkBlockExtra) { 67 return ErrBadNoDAOExtra 68 } 69 } 70 // All ok, header has the same extra-data we expect 71 return nil 72 } 73 74 // ApplyDAOHardFork modifies the state database according to the DAO hard-fork 75 // rules, transferring all balances of a set of DAO accounts to a single refund 76 // contract. 77 func ApplyDAOHardFork(statedb *state.StateDB) { 78 // Retrieve the contract to refund balances into 79 if !statedb.Exist(params.DAORefundContract) { 80 statedb.CreateAccount(params.DAORefundContract) 81 } 82 83 // Move every DAO account and extra-balance account funds into the refund contract 84 for _, addr := range params.DAODrainList() { 85 statedb.AddBalance(params.DAORefundContract, statedb.GetBalance(addr), tracing.BalanceIncreaseDaoContract) 86 statedb.SetBalance(addr, new(uint256.Int), tracing.BalanceDecreaseDaoAccount) 87 } 88 }