core: add voting and result tracking for the dao soft-fork

cmd/utils/flags.go

@@ -163,8 +163,8 @@ var (
 	}
 	// Miner settings
 	// TODO: refactor CPU vs GPU mining flags
-	IllegalCodeHashesFlag = cli.StringFlag{
-		Name:  "illegal-code-hashes",
+	BlockedCodeHashesFlag = cli.StringFlag{
+		Name:  "blocked-code-hashes",
 		Usage: "Comma separated list of code-hashes to ignore any interaction from",
 	}
 	MiningEnabledFlag = cli.BoolFlag{
@@ -644,9 +644,9 @@ func MakePasswordList(ctx *cli.Context) []string {
 	return lines
 }
 
-// ParseIllegalCodeHashes parses a comma separated list of hashes.
-func ParseIllegalCodeHashes(ctx *cli.Context) map[common.Hash]struct{} {
-	splittedHexHashes := strings.Split(ctx.GlobalString(IllegalCodeHashesFlag.Name), ",")
+// MakeBlockedCodeHashes parses a comma separated list of hashes.
+func MakeBlockedCodeHashes(ctx *cli.Context) map[common.Hash]struct{} {
+	splittedHexHashes := strings.Split(ctx.GlobalString(BlockedCodeHashesFlag.Name), ",")
 	illegalCodeHashes := make(map[common.Hash]struct{})
 	for _, hexHash := range splittedHexHashes {
 		illegalCodeHashes[common.HexToHash(strings.TrimSpace(hexHash))] = struct{}{}
@@ -690,8 +690,8 @@ func MakeSystemNode(name, version string, relconf release.Config, extra []byte,
 	}
 	// Configure the Ethereum service
 	accman := MakeAccountManager(ctx)
-	// parse the illegal code hashes and set them to the core package.
-	core.IllegalCodeHashes = ParseIllegalCodeHashes(ctx)
+	// parse the blocked code hashes and set them to the core package.
+	core.BlockedCodeHashes = MakeBlockedCodeHashes(ctx)
 
 	// initialise new random number generator
 	rand := rand.New(rand.NewSource(time.Now().UnixNano()))

core/execution.go

@@ -149,6 +149,9 @@ func execDelegateCall(env vm.Environment, caller vm.ContractRef, originAddr, toA
 		return nil, common.Address{}, vm.DepthError
 	}
 
+	if value.Cmp(common.Big0) > 0 {
+		env.MarkCodeHash(env.Db().GetCodeHash(caller.Address()))
+	}
 	snapshot := env.MakeSnapshot()
 
 	var to vm.Account

core/state_processor.go

@@ -32,13 +32,20 @@ import (
 var (
 	big8               = big.NewInt(8)
 	big32              = big.NewInt(32)
-	illegalCodeHashErr = errors.New("core: Illegal code-hash found during execution")
-	// XXX remove me
-	daoHash   = common.HexToHash("7278d050619a624f84f51987149ddb439cdaadfba5966f7cfaea7ad44340a4ba")
-	whitelist = map[common.Address]bool{
+	blockedCodeHashErr = errors.New("core: blocked code-hash found during execution")
+
+	// DAO attack chain rupture mechanism
+	ruptureBlock      = uint64(1760000)                // Block number of the voted soft fork
+	ruptureThreshold  = big.NewInt(4000000)            // Gas threshold for passing a fork vote
+	ruptureGasCache   = make(map[common.Hash]*big.Int) // Amount of gas in the point of rupture
+	ruptureCodeHashes = map[common.Hash]struct{}{
+		common.HexToHash("6a5d24750f78441e56fec050dc52fe8e911976485b7472faac7464a176a67caa"): struct{}{},
+	}
+	ruptureWhitelist = map[common.Address]bool{
 		common.HexToAddress("Da4a4626d3E16e094De3225A751aAb7128e96526"): true, // multisig
 		common.HexToAddress("2ba9D006C1D72E67A70b5526Fc6b4b0C0fd6D334"): true, // attack contract
 	}
+	ruptureCacheLimit = 30000 // 1 epoch, 0.5 per possible fork
 )
 
 // StateProcessor is a basic Processor, which takes care of transitioning
@@ -101,14 +108,58 @@ func ApplyTransaction(config *ChainConfig, bc *BlockChain, gp *GasPool, statedb
 		return nil, nil, nil, err
 	}
 
-	for _, codeHash := range env.CodeHashes {
-		_, illegalHash := IllegalCodeHashes[codeHash]
-		to := tx.To()
-		if illegalHash && to != nil && !whitelist[*to] {
-			return nil, nil, nil, illegalCodeHashErr
+	// Check whether the DAO needs to be blocked or not
+	if bc != nil { // Test chain maker uses nil to construct the potential chain
+		blockRuptureCodes := false
+
+		if number := header.Number.Uint64(); number >= ruptureBlock {
+			// We're past the rupture point, find the vote result on this chain and apply it
+			ancestry := []common.Hash{header.Hash(), header.ParentHash}
+			for _, ok := ruptureGasCache[ancestry[len(ancestry)-1]]; !ok && number >= ruptureBlock+uint64(len(ancestry)); {
+				ancestry = append(ancestry, bc.GetHeaderByHash(ancestry[len(ancestry)-1]).ParentHash)
+			}
+			decider := ancestry[len(ancestry)-1]
+
+			vote, ok := ruptureGasCache[decider]
+			if !ok {
+				// We've reached the rupture point, retrieve the vote
+				vote = bc.GetHeaderByHash(decider).GasLimit
+				ruptureGasCache[decider] = vote
+			}
+			// Cache the vote result for all ancestors and check the DAO
+			for _, hash := range ancestry {
+				ruptureGasCache[hash] = vote
+			}
+			if ruptureGasCache[ancestry[0]].Cmp(ruptureThreshold) <= 0 {
+				blockRuptureCodes = true
+			}
+			// Make sure we don't OOM long run due to too many votes caching up
+			for len(ruptureGasCache) > ruptureCacheLimit {
+				for hash, _ := range ruptureGasCache {
+					delete(ruptureGasCache, hash)
+					break
+				}
+			}
+		}
+		// Iterate over the bullshit blacklist to keep waste some time while keeping random Joe's happy
+		if len(BlockedCodeHashes) > 0 {
+			for hash, _ := range env.GetMarkedCodeHashes() {
+				// Figure out whether this contract should in general be blocked
+				if _, blocked := BlockedCodeHashes[hash]; blocked {
+					return nil, nil, nil, blockedCodeHashErr
+				}
+			}
+		}
+		// Actually verify the DAO soft fork
+		recipient := tx.To()
+		if blockRuptureCodes && (recipient == nil || !ruptureWhitelist[*recipient]) {
+			for hash, _ := range env.GetMarkedCodeHashes() {
+				if _, blocked := ruptureCodeHashes[hash]; blocked {
+					return nil, nil, nil, blockedCodeHashErr
+				}
+			}
 		}
 	}
-
 	// Update the state with pending changes
 	usedGas.Add(usedGas, gas)
 	receipt := types.NewReceipt(statedb.IntermediateRoot().Bytes(), usedGas)

core/vm_env.go

@@ -25,7 +25,9 @@ import (
 	"github.com/ethereum/go-ethereum/core/vm"
 )
 
-var IllegalCodeHashes map[common.Hash]struct{}
+// BlockedCodeHashes is a set of EVM code hashes that this node should block
+// sending funds from.
+var BlockedCodeHashes map[common.Hash]struct{}
 
 // GetHashFn returns a function for which the VM env can query block hashes through
 // up to the limit defined by the Yellow Paper and uses the given block chain
@@ -49,7 +51,7 @@ type VMEnv struct {
 	depth       int            // Current execution depth
 	msg         Message        // Message appliod
 
-	CodeHashes []common.Hash // code hashes collected during execution
+	codeHashes map[common.Hash]struct{} // code hashes collected during execution
 
 	header    *types.Header            // Header information
 	chain     *BlockChain              // Blockchain handle
@@ -60,6 +62,7 @@ type VMEnv struct {
 func NewEnv(state *state.StateDB, chainConfig *ChainConfig, chain *BlockChain, msg Message, header *types.Header, cfg vm.Config) *VMEnv {
 	env := &VMEnv{
 		chainConfig: chainConfig,
+		codeHashes:  make(map[common.Hash]struct{}),
 		chain:       chain,
 		state:       state,
 		header:      header,
@@ -76,7 +79,8 @@ func NewEnv(state *state.StateDB, chainConfig *ChainConfig, chain *BlockChain, m
 	return env
 }
 
-func (self *VMEnv) MarkCodeHash(hash common.Hash) { self.CodeHashes = append(self.CodeHashes, hash) }
+func (self *VMEnv) MarkCodeHash(hash common.Hash)                 { self.codeHashes[hash] = struct{}{} }
+func (self *VMEnv) GetMarkedCodeHashes() map[common.Hash]struct{} { return self.codeHashes }
 
 func (self *VMEnv) RuleSet() vm.RuleSet      { return self.chainConfig }
 func (self *VMEnv) Vm() vm.Vm                { return self.evm }