cmd, core, miner: add extradata validation to consensus rules

cmd/geth/genesis_test.go

@@ -75,7 +75,8 @@ var customGenesisTests = []struct {
 			"timestamp"  : "0x00",
 			"config"     : {
 				"homesteadBlock" : 314,
-				"daoForkBlock"   : 141
+				"daoForkBlock"   : 141,
+				"daoForkSupport" : true
 			},
 		}`,
 		query:  "eth.getBlock(0).nonce",

cmd/utils/flags.go

@@ -798,43 +798,42 @@ func MustMakeChainConfig(ctx *cli.Context) *core.ChainConfig {
 // MustMakeChainConfigFromDb reads the chain configuration from the given database.
 func MustMakeChainConfigFromDb(ctx *cli.Context, db ethdb.Database) *core.ChainConfig {
 	// If the chain is already initialized, use any existing chain configs
+	config := new(core.ChainConfig)
+
 	if genesis := core.GetBlock(db, core.GetCanonicalHash(db, 0), 0); genesis != nil {
 		storedConfig, err := core.GetChainConfig(db, genesis.Hash())
-		if err == nil {
-			// Force override any existing configs if explicitly requested
-			switch {
-			case storedConfig.DAOForkBlock == nil && ctx.GlobalBool(SupportDAOFork.Name) && ctx.GlobalBool(TestNetFlag.Name):
-				storedConfig.DAOForkBlock = params.TestNetDAOForkBlock
-			case storedConfig.DAOForkBlock == nil && ctx.GlobalBool(SupportDAOFork.Name):
-				storedConfig.DAOForkBlock = params.MainNetDAOForkBlock
-			case ctx.GlobalBool(OpposeDAOFork.Name):
-				storedConfig.DAOForkBlock = nil
-			}
-			return storedConfig
-		} else if err != core.ChainConfigNotFoundErr {
+		switch err {
+		case nil:
+			config = storedConfig
+		case core.ChainConfigNotFoundErr:
+			// No configs found, use empty, will populate below
+		default:
 			Fatalf("Could not make chain configuration: %v", err)
 		}
 	}
-	// If the chain is uninitialized nor no configs are present, create one
-	var homesteadBlock *big.Int
+	// Set any missing fields due to them being unset or system upgrade
+	if config.HomesteadBlock == nil {
+		if ctx.GlobalBool(TestNetFlag.Name) {
+			config.HomesteadBlock = new(big.Int).Set(params.TestNetHomesteadBlock)
+		} else {
+			config.HomesteadBlock = new(big.Int).Set(params.MainNetHomesteadBlock)
+		}
+	}
+	if config.DAOForkBlock == nil {
 		if ctx.GlobalBool(TestNetFlag.Name) {
-		homesteadBlock = params.TestNetHomesteadBlock
+			config.DAOForkBlock = new(big.Int).Set(params.TestNetDAOForkBlock)
 		} else {
-		homesteadBlock = params.MainNetHomesteadBlock
+			config.DAOForkBlock = new(big.Int).Set(params.MainNetDAOForkBlock)
 		}
-	var daoForkBlock *big.Int
+	}
+	// Force override any existing configs if explicitly requested
 	switch {
-	case ctx.GlobalBool(SupportDAOFork.Name) && ctx.GlobalBool(TestNetFlag.Name):
-		daoForkBlock = params.TestNetDAOForkBlock
 	case ctx.GlobalBool(SupportDAOFork.Name):
-		daoForkBlock = params.MainNetDAOForkBlock
+		config.DAOForkSupport = true
 	case ctx.GlobalBool(OpposeDAOFork.Name):
-		daoForkBlock = nil
-	}
-	return &core.ChainConfig{
-		HomesteadBlock: homesteadBlock,
-		DAOForkBlock:   daoForkBlock,
+		config.DAOForkSupport = false
 	}
+	return config
 }
 
 // MakeChainDatabase open an LevelDB using the flags passed to the client and will hard crash if it fails.

core/block_validator.go

@@ -17,6 +17,7 @@
 package core
 
 import (
+	"bytes"
 	"fmt"
 	"math/big"
 	"time"
@@ -247,6 +248,26 @@ func ValidateHeader(config *ChainConfig, pow pow.PoW, header *types.Header, pare
 			return &BlockNonceErr{header.Number, header.Hash(), header.Nonce.Uint64()}
 		}
 	}
+	// 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.
+	if daoBlock := config.DAOForkBlock; daoBlock != nil {
+		// Check whether the block is among the fork extra-override range
+		limit := new(big.Int).Add(daoBlock, params.DAOForkExtraRange)
+		if daoBlock.Cmp(header.Number) <= 0 && header.Number.Cmp(limit) < 0 {
+			// Depending whether we support or oppose the fork, verrift the extra-data contents
+			if config.DAOForkSupport {
+				if bytes.Compare(header.Extra, params.DAOForkBlockExtra) != 0 {
+					return ValidationError("DAO pro-fork bad block extra-data: 0x%x", header.Extra)
+				}
+			} else {
+				if bytes.Compare(header.Extra, params.DAOForkBlockExtra) == 0 {
+					return ValidationError("DAO no-fork bad block extra-data: 0x%x", header.Extra)
+				}
+			}
+		}
+	}
 	return nil
 }
 

core/block_validator_test.go

@@ -27,6 +27,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/pow/ezp"
 )
 
@@ -92,3 +93,107 @@ func TestPutReceipt(t *testing.T) {
 		t.Error("expected to get 1 receipt, got none.")
 	}
 }
+
+// Tests that DAO-fork enabled clients can properly filter out fork-commencing
+// blocks based on their extradata fields.
+func TestDAOForkRangeExtradata(t *testing.T) {
+	forkBlock := big.NewInt(32)
+
+	// Generate a common prefix for both pro-forkers and non-forkers
+	db, _ := ethdb.NewMemDatabase()
+	genesis := WriteGenesisBlockForTesting(db)
+	prefix, _ := GenerateChain(genesis, db, int(forkBlock.Int64()-1), func(i int, gen *BlockGen) {})
+
+	// Create the concurrent, conflicting two nodes
+	proDb, _ := ethdb.NewMemDatabase()
+	WriteGenesisBlockForTesting(proDb)
+	proBc, _ := NewBlockChain(proDb, &ChainConfig{HomesteadBlock: big.NewInt(0), DAOForkBlock: forkBlock, DAOForkSupport: true}, new(FakePow), new(event.TypeMux))
+
+	conDb, _ := ethdb.NewMemDatabase()
+	WriteGenesisBlockForTesting(conDb)
+	conBc, _ := NewBlockChain(conDb, &ChainConfig{HomesteadBlock: big.NewInt(0), DAOForkBlock: forkBlock, DAOForkSupport: false}, new(FakePow), new(event.TypeMux))
+
+	if _, err := proBc.InsertChain(prefix); err != nil {
+		t.Fatalf("pro-fork: failed to import chain prefix: %v", err)
+	}
+	if _, err := conBc.InsertChain(prefix); err != nil {
+		t.Fatalf("con-fork: failed to import chain prefix: %v", err)
+	}
+	// Try to expand both pro-fork and non-fork chains iteratively with other camp's blocks
+	for i := int64(0); i < params.DAOForkExtraRange.Int64(); i++ {
+		// Create a pro-fork block, and try to feed into the no-fork chain
+		db, _ = ethdb.NewMemDatabase()
+		WriteGenesisBlockForTesting(db)
+		bc, _ := NewBlockChain(db, &ChainConfig{HomesteadBlock: big.NewInt(0)}, new(FakePow), new(event.TypeMux))
+
+		blocks := conBc.GetBlocksFromHash(conBc.CurrentBlock().Hash(), int(conBc.CurrentBlock().NumberU64()+1))
+		for j := 0; j < len(blocks)/2; j++ {
+			blocks[j], blocks[len(blocks)-1-j] = blocks[len(blocks)-1-j], blocks[j]
+		}
+		if _, err := bc.InsertChain(blocks); err != nil {
+			t.Fatalf("failed to import contra-fork chain for expansion: %v", err)
+		}
+		blocks, _ = GenerateChain(conBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) { gen.SetExtra(params.DAOForkBlockExtra) })
+		if _, err := conBc.InsertChain(blocks); err == nil {
+			t.Fatalf("contra-fork chain accepted pro-fork block: %v", blocks[0])
+		}
+		// Create a proper no-fork block for the contra-forker
+		blocks, _ = GenerateChain(conBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
+		if _, err := conBc.InsertChain(blocks); err != nil {
+			t.Fatalf("contra-fork chain didn't accepted no-fork block: %v", err)
+		}
+		// Create a no-fork block, and try to feed into the pro-fork chain
+		db, _ = ethdb.NewMemDatabase()
+		WriteGenesisBlockForTesting(db)
+		bc, _ = NewBlockChain(db, &ChainConfig{HomesteadBlock: big.NewInt(0)}, new(FakePow), new(event.TypeMux))
+
+		blocks = proBc.GetBlocksFromHash(proBc.CurrentBlock().Hash(), int(proBc.CurrentBlock().NumberU64()+1))
+		for j := 0; j < len(blocks)/2; j++ {
+			blocks[j], blocks[len(blocks)-1-j] = blocks[len(blocks)-1-j], blocks[j]
+		}
+		if _, err := bc.InsertChain(blocks); err != nil {
+			t.Fatalf("failed to import pro-fork chain for expansion: %v", err)
+		}
+		blocks, _ = GenerateChain(proBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
+		if _, err := proBc.InsertChain(blocks); err == nil {
+			t.Fatalf("pro-fork chain accepted contra-fork block: %v", blocks[0])
+		}
+		// Create a proper pro-fork block for the pro-forker
+		blocks, _ = GenerateChain(proBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) { gen.SetExtra(params.DAOForkBlockExtra) })
+		if _, err := proBc.InsertChain(blocks); err != nil {
+			t.Fatalf("pro-fork chain didn't accepted pro-fork block: %v", err)
+		}
+	}
+	// Verify that contra-forkers accept pro-fork extra-datas after forking finishes
+	db, _ = ethdb.NewMemDatabase()
+	WriteGenesisBlockForTesting(db)
+	bc, _ := NewBlockChain(db, &ChainConfig{HomesteadBlock: big.NewInt(0)}, new(FakePow), new(event.TypeMux))
+
+	blocks := conBc.GetBlocksFromHash(conBc.CurrentBlock().Hash(), int(conBc.CurrentBlock().NumberU64()+1))
+	for j := 0; j < len(blocks)/2; j++ {
+		blocks[j], blocks[len(blocks)-1-j] = blocks[len(blocks)-1-j], blocks[j]
+	}
+	if _, err := bc.InsertChain(blocks); err != nil {
+		t.Fatalf("failed to import contra-fork chain for expansion: %v", err)
+	}
+	blocks, _ = GenerateChain(conBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) { gen.SetExtra(params.DAOForkBlockExtra) })
+	if _, err := conBc.InsertChain(blocks); err != nil {
+		t.Fatalf("contra-fork chain didn't accept pro-fork block post-fork: %v", err)
+	}
+	// Verify that pro-forkers accept contra-fork extra-datas after forking finishes
+	db, _ = ethdb.NewMemDatabase()
+	WriteGenesisBlockForTesting(db)
+	bc, _ = NewBlockChain(db, &ChainConfig{HomesteadBlock: big.NewInt(0)}, new(FakePow), new(event.TypeMux))
+
+	blocks = proBc.GetBlocksFromHash(proBc.CurrentBlock().Hash(), int(proBc.CurrentBlock().NumberU64()+1))
+	for j := 0; j < len(blocks)/2; j++ {
+		blocks[j], blocks[len(blocks)-1-j] = blocks[len(blocks)-1-j], blocks[j]
+	}
+	if _, err := bc.InsertChain(blocks); err != nil {
+		t.Fatalf("failed to import pro-fork chain for expansion: %v", err)
+	}
+	blocks, _ = GenerateChain(proBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
+	if _, err := proBc.InsertChain(blocks); err != nil {
+		t.Fatalf("pro-fork chain didn't accept contra-fork block post-fork: %v", err)
+	}
+}

core/config.go

@@ -31,8 +31,9 @@ var ChainConfigNotFoundErr = errors.New("ChainConfig not found") // general conf
 // that any network, identified by its genesis block, can have its own
 // set of configuration options.
 type ChainConfig struct {
-	HomesteadBlock *big.Int `json:"homesteadBlock"` // homestead switch block (0 = already homestead)
-	DAOForkBlock   *big.Int `json:"daoForkBlock"`   // TheDAO hard-fork block (nil = no fork)
+	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
 
 	VmConfig vm.Config `json:"-"`
 }

miner/worker.go

@@ -17,6 +17,7 @@
 package miner
 
 import (
+	"bytes"
 	"fmt"
 	"math/big"
 	"sync"
@@ -469,12 +470,17 @@ func (self *worker) commitNewWork() {
 		Extra:      self.extra,
 		Time:       big.NewInt(tstamp),
 	}
-	// If we are doing a DAO hard-fork check whether to override the extra-data or not
+	// If we are care about TheDAO hard-fork check whether to override the extra-data or not
 	if daoBlock := self.config.DAOForkBlock; daoBlock != nil {
 		// Check whether the block is among the fork extra-override range
 		limit := new(big.Int).Add(daoBlock, params.DAOForkExtraRange)
 		if daoBlock.Cmp(header.Number) <= 0 && header.Number.Cmp(limit) < 0 {
+			// Depending whether we support or oppose the fork, override differently
+			if self.config.DAOForkSupport {
 				header.Extra = common.CopyBytes(params.DAOForkBlockExtra)
+			} else if bytes.Compare(header.Extra, params.DAOForkBlockExtra) == 0 {
+				header.Extra = []byte{} // If miner opposes, don't let it use the reserved extra-data
+			}
 		}
 	}
 	previous := self.current