go-ethereum/core/dao.go
Felix Lange 37dd9086ec core: refactor genesis handling
This commit solves several issues concerning the genesis block:

* Genesis/ChainConfig loading was handled by cmd/geth code. This left
  library users in the cold. They could specify a JSON-encoded
  string and overwrite the config, but didn't get any of the additional
  checks performed by geth.
* Decoding and writing of genesis JSON was conflated in
  WriteGenesisBlock. This made it a lot harder to embed the genesis
  block into the forthcoming config file loader. This commit changes
  things so there is a single Genesis type that represents genesis
  blocks. All uses of Write*Genesis* are changed to use the new type
  instead.
* If the chain config supplied by the user was incompatible with the
  current chain (i.e. the chain had already advanced beyond a scheduled
  fork), it got overwritten. This is not an issue in practice because
  previous forks have always had the highest total difficulty. It might
  matter in the future though. The new code reverts the local chain to
  the point of the fork when upgrading configuration.

The change to genesis block data removes compression library
dependencies from package core.
2017-03-23 15:58:43 +01:00

75 lines
2.9 KiB
Go

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package core
import (
"bytes"
"math/big"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/params"
)
// ValidateDAOHeaderExtraData validates the extra-data field of a block header to
// ensure it conforms to DAO hard-fork rules.
//
// DAO hard-fork extension to the header validity:
// a) if the node is no-fork, do not accept blocks in the [fork, fork+10) range
// with the fork specific extra-data set
// b) if the node is pro-fork, require blocks in the specific range to have the
// unique extra-data set.
func ValidateDAOHeaderExtraData(config *params.ChainConfig, header *types.Header) error {
// Short circuit validation if the node doesn't care about the DAO fork
if config.DAOForkBlock == nil {
return nil
}
// Make sure the block is within the fork's modified extra-data range
limit := new(big.Int).Add(config.DAOForkBlock, params.DAOForkExtraRange)
if header.Number.Cmp(config.DAOForkBlock) < 0 || header.Number.Cmp(limit) >= 0 {
return nil
}
// Depending whether we support or oppose the fork, validate the extra-data contents
if config.DAOForkSupport {
if !bytes.Equal(header.Extra, params.DAOForkBlockExtra) {
return ValidationError("DAO pro-fork bad block extra-data: 0x%x", header.Extra)
}
} else {
if bytes.Equal(header.Extra, params.DAOForkBlockExtra) {
return ValidationError("DAO no-fork bad block extra-data: 0x%x", header.Extra)
}
}
// All ok, header has the same extra-data we expect
return nil
}
// ApplyDAOHardFork modifies the state database according to the DAO hard-fork
// rules, transferring all balances of a set of DAO accounts to a single refund
// contract.
func ApplyDAOHardFork(statedb *state.StateDB) {
// Retrieve the contract to refund balances into
if !statedb.Exist(params.DAORefundContract) {
statedb.CreateAccount(params.DAORefundContract)
}
// Move every DAO account and extra-balance account funds into the refund contract
for _, addr := range params.DAODrainList() {
statedb.AddBalance(params.DAORefundContract, statedb.GetBalance(addr))
statedb.SetBalance(addr, new(big.Int))
}
}