path: root/params/config.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 params

import (
    "fmt"
    "math/big"

    "github.com/ethereum/go-ethereum/common"
)

var (
    // MainnetChainConfig is the chain parameters to run a node on the main network.
    MainnetChainConfig = &ChainConfig{
        ChainId:        MainNetChainID,
        HomesteadBlock: MainNetHomesteadBlock,
        DAOForkBlock:   MainNetDAOForkBlock,
        DAOForkSupport: true,
        EIP150Block:    MainNetHomesteadGasRepriceBlock,
        EIP150Hash:     MainNetHomesteadGasRepriceHash,
        EIP155Block:    MainNetSpuriousDragon,
        EIP158Block:    MainNetSpuriousDragon,
    }

    // TestnetChainConfig contains the chain parameters to run a node on the ropsten test network.
    TestnetChainConfig = &ChainConfig{
        ChainId:        big.NewInt(3),
        HomesteadBlock: big.NewInt(0),
        DAOForkBlock:   nil,
        DAOForkSupport: true,
        EIP150Block:    big.NewInt(0),
        EIP150Hash:     common.HexToHash("0x41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1ca4a2d"),
        EIP155Block:    big.NewInt(10),
        EIP158Block:    big.NewInt(10),
    }

    // AllProtocolChanges contains every protocol change (EIPs)
    // introduced and accepted by the Ethereum core developers.
    // TestChainConfig is like AllProtocolChanges but has chain ID 1.
    //
    // This configuration is intentionally not using keyed fields.
    // This configuration must *always* have all forks enabled, which
    // means that all fields must be set at all times. This forces
    // anyone adding flags to the config to also have to set these
    // fields.
    AllProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0)}
    TestChainConfig    = &ChainConfig{big.NewInt(1), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0)}
)

// ChainConfig is the core config which determines the blockchain settings.
//
// ChainConfig is stored in the database on a per block basis. This means
// that any network, identified by its genesis block, can have its own
// set of configuration options.
type ChainConfig struct {
    ChainId *big.Int `json:"chainId"` // Chain id identifies the current chain and is used for replay protection

    HomesteadBlock *big.Int `json:"homesteadBlock"` // Homestead switch block (nil = no fork, 0 = already homestead)
    DAOForkBlock   *big.Int `json:"daoForkBlock"`   // TheDAO hard-fork switch block (nil = no fork)
    DAOForkSupport bool     `json:"daoForkSupport"` // Whether the nodes supports or opposes the DAO hard-fork

    // EIP150 implements the Gas price changes (https://github.com/ethereum/EIPs/issues/150)
    EIP150Block *big.Int    `json:"eip150Block"` // EIP150 HF block (nil = no fork)
    EIP150Hash  common.Hash `json:"eip150Hash"`  // EIP150 HF hash (fast sync aid)

    EIP155Block *big.Int `json:"eip155Block"` // EIP155 HF block
    EIP158Block *big.Int `json:"eip158Block"` // EIP158 HF block
}

// String implements the fmt.Stringer interface.
func (c *ChainConfig) String() string {
    return fmt.Sprintf("{ChainID: %v Homestead: %v DAO: %v DAOSupport: %v EIP150: %v EIP155: %v EIP158: %v}",
        c.ChainId,
        c.HomesteadBlock,
        c.DAOForkBlock,
        c.DAOForkSupport,
        c.EIP150Block,
        c.EIP155Block,
        c.EIP158Block,
    )
}

// IsHomestead returns whether num is either equal to the homestead block or greater.
func (c *ChainConfig) IsHomestead(num *big.Int) bool {
    return isForked(c.HomesteadBlock, num)
}

// IsDAO returns whether num is either equal to the DAO fork block or greater.
func (c *ChainConfig) IsDAOFork(num *big.Int) bool {
    return isForked(c.DAOForkBlock, num)
}

func (c *ChainConfig) IsEIP150(num *big.Int) bool {
    return isForked(c.EIP150Block, num)
}

func (c *ChainConfig) IsEIP155(num *big.Int) bool {
    return isForked(c.EIP155Block, num)
}

func (c *ChainConfig) IsEIP158(num *big.Int) bool {
    return isForked(c.EIP158Block, num)
}

// GasTable returns the gas table corresponding to the current phase (homestead or homestead reprice).
//
// The returned GasTable's fields shouldn't, under any circumstances, be changed.
func (c *ChainConfig) GasTable(num *big.Int) GasTable {
    if num == nil {
        return GasTableHomestead
    }
    switch {
    case c.IsEIP158(num):
        return GasTableEIP158
    case c.IsEIP150(num):
        return GasTableHomesteadGasRepriceFork
    default:
        return GasTableHomestead
    }
}

// CheckCompatible checks whether scheduled fork transitions have been imported
// with a mismatching chain configuration.
func (c *ChainConfig) CheckCompatible(newcfg *ChainConfig, height uint64) *ConfigCompatError {
    bhead := new(big.Int).SetUint64(height)

    // Iterate checkCompatible to find the lowest conflict.
    var lasterr *ConfigCompatError
    for {
        err := c.checkCompatible(newcfg, bhead)
        if err == nil || (lasterr != nil && err.RewindTo == lasterr.RewindTo) {
            break
        }
        lasterr = err
        bhead.SetUint64(err.RewindTo)
    }
    return lasterr
}

func (c *ChainConfig) checkCompatible(newcfg *ChainConfig, head *big.Int) *ConfigCompatError {
    if isForkIncompatible(c.HomesteadBlock, newcfg.HomesteadBlock, head) {
        return newCompatError("Homestead fork block", c.HomesteadBlock, newcfg.HomesteadBlock)
    }
    if isForkIncompatible(c.DAOForkBlock, newcfg.DAOForkBlock, head) {
        return newCompatError("DAO fork block", c.DAOForkBlock, newcfg.DAOForkBlock)
    }
    if c.IsDAOFork(head) && c.DAOForkSupport != newcfg.DAOForkSupport {
        return newCompatError("DAO fork support flag", c.DAOForkBlock, newcfg.DAOForkBlock)
    }
    if isForkIncompatible(c.EIP150Block, newcfg.EIP150Block, head) {
        return newCompatError("EIP150 fork block", c.EIP150Block, newcfg.EIP150Block)
    }
    if isForkIncompatible(c.EIP155Block, newcfg.EIP155Block, head) {
        return newCompatError("EIP155 fork block", c.EIP155Block, newcfg.EIP155Block)
    }
    if isForkIncompatible(c.EIP158Block, newcfg.EIP158Block, head) {
        return newCompatError("EIP158 fork block", c.EIP158Block, newcfg.EIP158Block)
    }
    if c.IsEIP158(head) && !configNumEqual(c.ChainId, newcfg.ChainId) {
        return newCompatError("EIP158 chain ID", c.EIP158Block, newcfg.EIP158Block)
    }
    return nil
}

// isForkIncompatible returns true if a fork scheduled at s1 cannot be rescheduled to
// block s2 because head is already past the fork.
func isForkIncompatible(s1, s2, head *big.Int) bool {
    return (isForked(s1, head) || isForked(s2, head)) && !configNumEqual(s1, s2)
}

// isForked returns whether a fork scheduled at block s is active at the given head block.
func isForked(s, head *big.Int) bool {
    if s == nil || head == nil {
        return false
    }
    return s.Cmp(head) <= 0
}

func configNumEqual(x, y *big.Int) bool {
    if x == nil {
        return y == nil
    }
    if y == nil {
        return x == nil
    }
    return x.Cmp(y) == 0
}

// ConfigCompatError is raised if the locally-stored blockchain is initialised with a
// ChainConfig that would alter the past.
type ConfigCompatError struct {
    What string
    // block numbers of the stored and new configurations
    StoredConfig, NewConfig *big.Int
    // the block number to which the local chain must be rewound to correct the error
    RewindTo uint64
}

func newCompatError(what string, storedblock, newblock *big.Int) *ConfigCompatError {
    var rew *big.Int
    switch {
    case storedblock == nil:
        rew = newblock
    case newblock == nil || storedblock.Cmp(newblock) < 0:
        rew = storedblock
    default:
        rew = newblock
    }
    err := &ConfigCompatError{what, storedblock, newblock, 0}
    if rew != nil && rew.Sign() > 0 {
        err.RewindTo = rew.Uint64() - 1
    }
    return err
}

func (err *ConfigCompatError) Error() string {
    return fmt.Sprintf("mismatching %s in database (have %d, want %d, rewindto %d)", err.What, err.StoredConfig, err.NewConfig, err.RewindTo)
}