github.com/devfans/go-ethereum@v1.5.10-0.20170326212234-7419d0c38291/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  	"math/big"
    22  
    23  	"github.com/ethereum/go-ethereum/core/state"
    24  	"github.com/ethereum/go-ethereum/core/types"
    25  	"github.com/ethereum/go-ethereum/params"
    26  )
    27  
    28  // ValidateDAOHeaderExtraData validates the extra-data field of a block header to
    29  // ensure it conforms to DAO hard-fork rules.
    30  //
    31  // DAO hard-fork extension to the header validity:
    32  //   a) if the node is no-fork, do not accept blocks in the [fork, fork+10) range
    33  //      with the fork specific extra-data set
    34  //   b) if the node is pro-fork, require blocks in the specific range to have the
    35  //      unique extra-data set.
    36  func ValidateDAOHeaderExtraData(config *params.ChainConfig, header *types.Header) error {
    37  	// Short circuit validation if the node doesn't care about the DAO fork
    38  	if config.DAOForkBlock == nil {
    39  		return nil
    40  	}
    41  	// Make sure the block is within the fork's modified extra-data range
    42  	limit := new(big.Int).Add(config.DAOForkBlock, params.DAOForkExtraRange)
    43  	if header.Number.Cmp(config.DAOForkBlock) < 0 || header.Number.Cmp(limit) >= 0 {
    44  		return nil
    45  	}
    46  	// Depending whether we support or oppose the fork, validate the extra-data contents
    47  	if config.DAOForkSupport {
    48  		if !bytes.Equal(header.Extra, params.DAOForkBlockExtra) {
    49  			return ValidationError("DAO pro-fork bad block extra-data: 0x%x", header.Extra)
    50  		}
    51  	} else {
    52  		if bytes.Equal(header.Extra, params.DAOForkBlockExtra) {
    53  			return ValidationError("DAO no-fork bad block extra-data: 0x%x", header.Extra)
    54  		}
    55  	}
    56  	// All ok, header has the same extra-data we expect
    57  	return nil
    58  }
    59  
    60  // ApplyDAOHardFork modifies the state database according to the DAO hard-fork
    61  // rules, transferring all balances of a set of DAO accounts to a single refund
    62  // contract.
    63  func ApplyDAOHardFork(statedb *state.StateDB) {
    64  	// Retrieve the contract to refund balances into
    65  	if !statedb.Exist(params.DAORefundContract) {
    66  		statedb.CreateAccount(params.DAORefundContract)
    67  	}
    68  
    69  	// Move every DAO account and extra-balance account funds into the refund contract
    70  	for _, addr := range params.DAODrainList() {
    71  		statedb.AddBalance(params.DAORefundContract, statedb.GetBalance(addr))
    72  		statedb.SetBalance(addr, new(big.Int))
    73  	}
    74  }