github.com/aigarnetwork/aigar@v0.0.0-20191115204914-d59a6eb70f8e/consensus/misc/dao.go (about)

     1  //  Copyright 2018 The go-ethereum Authors
     2  //  Copyright 2019 The go-aigar Authors
     3  //  This file is part of the go-aigar library.
     4  //
     5  //  The go-aigar library is free software: you can redistribute it and/or modify
     6  //  it under the terms of the GNU Lesser General Public License as published by
     7  //  the Free Software Foundation, either version 3 of the License, or
     8  //  (at your option) any later version.
     9  //
    10  //  The go-aigar library is distributed in the hope that it will be useful,
    11  //  but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    13  //  GNU Lesser General Public License for more details.
    14  //
    15  //  You should have received a copy of the GNU Lesser General Public License
    16  //  along with the go-aigar library. If not, see <http://www.gnu.org/licenses/>.
    17  
    18  package misc
    19  
    20  import (
    21  	"bytes"
    22  	"errors"
    23  	"math/big"
    24  
    25  	"github.com/AigarNetwork/aigar/core/state"
    26  	"github.com/AigarNetwork/aigar/core/types"
    27  	"github.com/AigarNetwork/aigar/params"
    28  )
    29  
    30  var (
    31  	// ErrBadProDAOExtra is returned if a header doens't support the DAO fork on a
    32  	// pro-fork client.
    33  	ErrBadProDAOExtra = errors.New("bad DAO pro-fork extra-data")
    34  
    35  	// ErrBadNoDAOExtra is returned if a header does support the DAO fork on a no-
    36  	// fork client.
    37  	ErrBadNoDAOExtra = errors.New("bad DAO no-fork extra-data")
    38  )
    39  
    40  // VerifyDAOHeaderExtraData validates the extra-data field of a block header to
    41  // ensure it conforms to DAO hard-fork rules.
    42  //
    43  // DAO hard-fork extension to the header validity:
    44  //   a) if the node is no-fork, do not accept blocks in the [fork, fork+10) range
    45  //      with the fork specific extra-data set
    46  //   b) if the node is pro-fork, require blocks in the specific range to have the
    47  //      unique extra-data set.
    48  func VerifyDAOHeaderExtraData(config *params.ChainConfig, header *types.Header) error {
    49  	// Short circuit validation if the node doesn't care about the DAO fork
    50  	if config.DAOForkBlock == nil {
    51  		return nil
    52  	}
    53  	// Make sure the block is within the fork's modified extra-data range
    54  	limit := new(big.Int).Add(config.DAOForkBlock, params.DAOForkExtraRange)
    55  	if header.Number.Cmp(config.DAOForkBlock) < 0 || header.Number.Cmp(limit) >= 0 {
    56  		return nil
    57  	}
    58  	// Depending on whether we support or oppose the fork, validate the extra-data contents
    59  	if config.DAOForkSupport {
    60  		if !bytes.Equal(header.Extra, params.DAOForkBlockExtra) {
    61  			return ErrBadProDAOExtra
    62  		}
    63  	} else {
    64  		if bytes.Equal(header.Extra, params.DAOForkBlockExtra) {
    65  			return ErrBadNoDAOExtra
    66  		}
    67  	}
    68  	// All ok, header has the same extra-data we expect
    69  	return nil
    70  }
    71  
    72  // ApplyDAOHardFork modifies the state database according to the DAO hard-fork
    73  // rules, transferring all balances of a set of DAO accounts to a single refund
    74  // contract.
    75  func ApplyDAOHardFork(statedb *state.StateDB) {
    76  	// Retrieve the contract to refund balances into
    77  	if !statedb.Exist(params.DAORefundContract) {
    78  		statedb.CreateAccount(params.DAORefundContract)
    79  	}
    80  
    81  	// Move every DAO account and extra-balance account funds into the refund contract
    82  	for _, addr := range params.DAODrainList() {
    83  		statedb.AddBalance(params.DAORefundContract, statedb.GetBalance(addr))
    84  		statedb.SetBalance(addr, new(big.Int))
    85  	}
    86  }