github.com/aswedchain/aswed@v1.0.1/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/aswedchain/aswed/core/state"
    25  	"github.com/aswedchain/aswed/core/types"
    26  	"github.com/aswedchain/aswed/params"
    27  )
    28  
    29  var (
    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.
    47  func 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.
    74  func 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  }