github.com/vantum/vantum@v0.0.0-20180815184342-fe37d5f7a990/core/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 core
    18  
    19  import (
    20  	"bytes"
    21  	"fmt"
    22  	"math/big"
    23  
    24  	"github.com/vantum/vantum/core/state"
    25  	"github.com/vantum/vantum/core/types"
    26  	"github.com/vantum/vantum/params"
    27  )
    28  
    29  // ValidateDAOHeaderExtraData validates the extra-data field of a block header to
    30  // ensure it conforms to DAO hard-fork rules.
    31  //
    32  // DAO hard-fork extension to the header validity:
    33  //   a) if the node is no-fork, do not accept blocks in the [fork, fork+10) range
    34  //      with the fork specific extra-data set
    35  //   b) if the node is pro-fork, require blocks in the specific range to have the
    36  //      unique extra-data set.
    37  func ValidateDAOHeaderExtraData(config *params.ChainConfig, header *types.Header) error {
    38  	// Short circuit validation if the node doesn't care about the DAO fork
    39  	if config.DAOForkBlock == nil {
    40  		return nil
    41  	}
    42  	// Make sure the block is within the fork's modified extra-data range
    43  	limit := new(big.Int).Add(config.DAOForkBlock, params.DAOForkExtraRange)
    44  	if header.Number.Cmp(config.DAOForkBlock) < 0 || header.Number.Cmp(limit) >= 0 {
    45  		return nil
    46  	}
    47  	// Depending whether we support or oppose the fork, validate the extra-data contents
    48  	if config.DAOForkSupport {
    49  		if !bytes.Equal(header.Extra, params.DAOForkBlockExtra) {
    50  			return fmt.Errorf("DAO pro-fork bad block extra-data: 0x%x", header.Extra)
    51  		}
    52  	} else {
    53  		if bytes.Equal(header.Extra, params.DAOForkBlockExtra) {
    54  			return fmt.Errorf("DAO no-fork bad block extra-data: 0x%x", header.Extra)
    55  		}
    56  	}
    57  	// All ok, header has the same extra-data we expect
    58  	return nil
    59  }
    60  
    61  // ApplyDAOHardFork modifies the state database according to the DAO hard-fork
    62  // rules, transferring all balances of a set of DAO accounts to a single refund
    63  // contract.
    64  func ApplyDAOHardFork(statedb *state.StateDB) {
    65  	// Retrieve the contract to refund balances into
    66  	if !statedb.Exist(params.DAORefundContract) {
    67  		statedb.CreateAccount(params.DAORefundContract)
    68  	}
    69  
    70  	// Move every DAO account and extra-balance account funds into the refund contract
    71  	for _, addr := range params.DAODrainList() {
    72  		statedb.AddBalance(params.DAORefundContract, statedb.GetBalance(addr))
    73  		statedb.SetBalance(addr, new(big.Int))
    74  	}
    75  }