[DEV-311] Enforce gas limit in blocks (#172)

* [DEV-311] Moved subnetwork storage from directly in DAG to subnetworkStore

* Added gas validation in CheckBlockSanity

* [DEV-311] Add SubnetworkStore to last remaining call for CheckBlockSanity

* [DEV-311] Added subnetworkID to config in TestcheckBlockSanity

* [DEV-311] Moved CheckBlockSanity to be method of BlockDAG, and removed subnetworkStore argument

* [DEV-311] Removed SubnetworkID as parameter to CheckBlockSanity

* [DEV-311] Update gas usage before

* [DEV-311] some chain=>DAG updates in comments

* [DEV-311] Removed remaining dag-specific parameters from checkBlockSanity

blockdag/dag.go

@@ -147,6 +147,8 @@ type BlockDAG struct {
 	notifications     []NotificationCallback
 
 	lastFinalityPoint *blockNode
+
+	SubnetworkStore *subnetworkStore
 }
 
 // HaveBlock returns whether or not the DAG instance has the block represented
@@ -1482,6 +1484,7 @@ func New(config *Config) (*BlockDAG, error) {
 		warningCaches:       newThresholdCaches(vbNumBits),
 		deploymentCaches:    newThresholdCaches(dagconfig.DefinedDeployments),
 		blockCount:          1,
+		SubnetworkStore:     newSubnetworkStore(config.DB),
 		subnetworkID:        config.SubnetworkID,
 	}
 

blockdag/process.go

@@ -164,7 +164,7 @@ func (dag *BlockDAG) ProcessBlock(block *util.Block, flags BehaviorFlags) (bool,
 	}
 
 	// Perform preliminary sanity checks on the block and its transactions.
-	err = checkBlockSanity(block, dag.dagParams.PowLimit, dag.timeSource, dag.subnetworkID, flags)
+	err = dag.checkBlockSanity(block, flags)
 	if err != nil {
 		return false, err
 	}

blockdag/subnetworks.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
+
 	"github.com/daglabs/btcd/util"
 
 	"github.com/daglabs/btcd/database"
@@ -11,6 +12,16 @@ import (
 	"github.com/daglabs/btcd/wire"
 )
 
+type subnetworkStore struct {
+	db database.DB
+}
+
+func newSubnetworkStore(db database.DB) *subnetworkStore {
+	return &subnetworkStore{
+		db: db,
+	}
+}
+
 // registerSubnetworks scans a list of accepted transactions, singles out
 // subnetwork registry transactions, validates them, and registers a new
 // subnetwork based on it.
@@ -77,10 +88,10 @@ func txToSubnetworkID(tx *wire.MsgTx) (*subnetworkid.SubnetworkID, error) {
 
 // subnetwork returns a registered subnetwork. If the subnetwork does not exist
 // this method returns an error.
-func (dag *BlockDAG) subnetwork(subnetworkID *subnetworkid.SubnetworkID) (*subnetwork, error) {
+func (s *subnetworkStore) subnetwork(subnetworkID *subnetworkid.SubnetworkID) (*subnetwork, error) {
 	var sNet *subnetwork
 	var err error
-	dbErr := dag.db.View(func(dbTx database.Tx) error {
+	dbErr := s.db.View(func(dbTx database.Tx) error {
 		sNet, err = dbGetSubnetwork(dbTx, subnetworkID)
 		return nil
 	})
@@ -96,8 +107,8 @@ func (dag *BlockDAG) subnetwork(subnetworkID *subnetworkid.SubnetworkID) (*subne
 
 // GasLimit returns the gas limit of a registered subnetwork. If the subnetwork does not
 // exist this method returns an error.
-func (dag *BlockDAG) GasLimit(subnetworkID *subnetworkid.SubnetworkID) (uint64, error) {
-	sNet, err := dag.subnetwork(subnetworkID)
+func (s *subnetworkStore) GasLimit(subnetworkID *subnetworkid.SubnetworkID) (uint64, error) {
+	sNet, err := s.subnetwork(subnetworkID)
 	if err != nil {
 		return 0, err
 	}

blockdag/subnetworks_test.go

@@ -26,7 +26,7 @@ func TestSubnetworkRegistry(t *testing.T) {
 	if err != nil {
 		t.Fatalf("could not register network: %s", err)
 	}
-	limit, err := dag.GasLimit(subnetworkID)
+	limit, err := dag.SubnetworkStore.GasLimit(subnetworkID)
 	if err != nil {
 		t.Fatalf("could not retrieve gas limit: %s", err)
 	}

blockdag/validate.go

@@ -283,7 +283,7 @@ func CheckTransactionSanity(tx *util.Tx, subnetworkID *subnetworkid.SubnetworkID
 // The flags modify the behavior of this function as follows:
 //  - BFNoPoWCheck: The check to ensure the block hash is less than the target
 //    difficulty is not performed.
-func checkProofOfWork(header *wire.BlockHeader, powLimit *big.Int, flags BehaviorFlags) error {
+func (dag *BlockDAG) checkProofOfWork(header *wire.BlockHeader, flags BehaviorFlags) error {
 	// The target difficulty must be larger than zero.
 	target := CompactToBig(header.Bits)
 	if target.Sign() <= 0 {
@@ -293,9 +293,9 @@ func checkProofOfWork(header *wire.BlockHeader, powLimit *big.Int, flags Behavio
 	}
 
 	// The target difficulty must be less than the maximum allowed.
-	if target.Cmp(powLimit) > 0 {
+	if target.Cmp(dag.dagParams.PowLimit) > 0 {
 		str := fmt.Sprintf("block target difficulty of %064x is "+
-			"higher than max of %064x", target, powLimit)
+			"higher than max of %064x", target, dag.dagParams.PowLimit)
 		return ruleError(ErrUnexpectedDifficulty, str)
 	}
 
@@ -399,11 +399,11 @@ func CountP2SHSigOps(tx *util.Tx, isCoinBaseTx bool, utxoSet UTXOSet) (int, erro
 //
 // The flags do not modify the behavior of this function directly, however they
 // are needed to pass along to checkProofOfWork.
-func checkBlockHeaderSanity(header *wire.BlockHeader, powLimit *big.Int, timeSource MedianTimeSource, flags BehaviorFlags) error {
+func (dag *BlockDAG) checkBlockHeaderSanity(header *wire.BlockHeader, flags BehaviorFlags) error {
 	// Ensure the proof of work bits in the block header is in min/max range
 	// and the block hash is less than the target value described by the
 	// bits.
-	err := checkProofOfWork(header, powLimit, flags)
+	err := dag.checkProofOfWork(header, flags)
 	if err != nil {
 		return err
 	}
@@ -425,7 +425,7 @@ func checkBlockHeaderSanity(header *wire.BlockHeader, powLimit *big.Int, timeSou
 	}
 
 	// Ensure the block time is not too far in the future.
-	maxTimestamp := timeSource.AdjustedTime().Add(time.Second *
+	maxTimestamp := dag.timeSource.AdjustedTime().Add(time.Second *
 		MaxTimeOffsetSeconds)
 	if header.Timestamp.After(maxTimestamp) {
 		str := fmt.Sprintf("block timestamp of %v is too far in the "+
@@ -456,11 +456,11 @@ func checkBlockParentsOrder(header *wire.BlockHeader) error {
 //
 // The flags do not modify the behavior of this function directly, however they
 // are needed to pass along to checkBlockHeaderSanity.
-func checkBlockSanity(block *util.Block, powLimit *big.Int, timeSource MedianTimeSource,
-	subnetworkID *subnetworkid.SubnetworkID, flags BehaviorFlags) error {
+func (dag *BlockDAG) checkBlockSanity(block *util.Block, flags BehaviorFlags) error {
+
 	msgBlock := block.MsgBlock()
 	header := &msgBlock.Header
-	err := checkBlockHeaderSanity(header, powLimit, timeSource, flags)
+	err := dag.checkBlockHeaderSanity(header, flags)
 	if err != nil {
 		return err
 	}
@@ -512,7 +512,7 @@ func checkBlockSanity(block *util.Block, powLimit *big.Int, timeSource MedianTim
 	// Do some preliminary checks on each transaction to ensure they are
 	// sane before continuing.
 	for _, tx := range transactions {
-		err := CheckTransactionSanity(tx, subnetworkID)
+		err := CheckTransactionSanity(tx, dag.subnetworkID)
 		if err != nil {
 			return err
 		}
@@ -572,13 +572,41 @@ func checkBlockSanity(block *util.Block, powLimit *big.Int, timeSource MedianTim
 		}
 	}
 
+	// Amount of gas consumed per sub-network shouldn't be more than the subnetwork's limit
+	gasUsageInAllSubnetworks := map[subnetworkid.SubnetworkID]uint64{}
+	for _, tx := range transactions {
+		msgTx := tx.MsgTx()
+		// In DAGCoin and Registry sub-networks all txs must have Gas = 0, and that is validated in checkTransactionSanity
+		// Therefore - no need to check them here.
+		if msgTx.SubnetworkID != wire.SubnetworkIDNative && msgTx.SubnetworkID != wire.SubnetworkIDRegistry {
+			gasUsageInSubnetwork := gasUsageInAllSubnetworks[msgTx.SubnetworkID]
+			gasUsageInSubnetwork += msgTx.Gas
+			if gasUsageInSubnetwork < gasUsageInAllSubnetworks[msgTx.SubnetworkID] { // protect from overflows
+				str := fmt.Sprintf("Block gas usage in subnetwork with ID %s has overflown", msgTx.SubnetworkID)
+				return ruleError(ErrInvalidGas, str)
+			}
+			gasUsageInAllSubnetworks[msgTx.SubnetworkID] = gasUsageInSubnetwork
+
+			gasLimit, err := dag.SubnetworkStore.GasLimit(&msgTx.SubnetworkID)
+			if err != nil {
+				return err
+			}
+			if gasUsageInSubnetwork > gasLimit {
+				str := fmt.Sprintf("Block wastes too much gas in subnetwork with ID %s", msgTx.SubnetworkID)
+				return ruleError(ErrInvalidGas, str)
+			}
+		}
+	}
+
 	return nil
 }
 
 // CheckBlockSanity performs some preliminary checks on a block to ensure it is
 // sane before continuing with block processing.  These checks are context free.
-func CheckBlockSanity(block *util.Block, powLimit *big.Int, timeSource MedianTimeSource, subnetworkID *subnetworkid.SubnetworkID) error {
-	return checkBlockSanity(block, powLimit, timeSource, subnetworkID, BFNone)
+func (dag *BlockDAG) CheckBlockSanity(block *util.Block, powLimit *big.Int,
+	timeSource MedianTimeSource) error {
+
+	return dag.checkBlockSanity(block, BFNone)
 }
 
 // ExtractCoinbaseHeight attempts to extract the height of the block from the
@@ -1106,7 +1134,7 @@ func (dag *BlockDAG) CheckConnectBlockTemplate(block *util.Block) error {
 		return ruleError(ErrParentBlockNotCurrentTips, str)
 	}
 
-	err := checkBlockSanity(block, dag.dagParams.PowLimit, dag.timeSource, dag.subnetworkID, flags)
+	err := dag.checkBlockSanity(block, flags)
 	if err != nil {
 		return err
 	}

blockdag/validate_test.go

@@ -73,7 +73,7 @@ func TestCheckConnectBlockTemplate(t *testing.T) {
 		SubnetworkID: &wire.SubnetworkIDSupportsAll,
 	})
 	if err != nil {
-		t.Errorf("Failed to setup chain instance: %v", err)
+		t.Errorf("Failed to setup dag instance: %v", err)
 		return
 	}
 	defer teardownFunc()
@@ -152,19 +152,30 @@ func TestCheckConnectBlockTemplate(t *testing.T) {
 // TestCheckBlockSanity tests the CheckBlockSanity function to ensure it works
 // as expected.
 func TestCheckBlockSanity(t *testing.T) {
+	// Create a new database and dag instance to run tests against.
+	dag, teardownFunc, err := DAGSetup("TestCheckBlockSanity", Config{
+		DAGParams:    &dagconfig.SimNetParams,
+		SubnetworkID: &wire.SubnetworkIDSupportsAll,
+	})
+	if err != nil {
+		t.Errorf("Failed to setup dag instance: %v", err)
+		return
+	}
+	defer teardownFunc()
+
 	powLimit := dagconfig.MainNetParams.PowLimit
 	block := util.NewBlock(&Block100000)
 	timeSource := NewMedianTime()
 	if len(block.Transactions()) < 3 {
 		t.Fatalf("Too few transactions in block, expect at least 3, got %v", len(block.Transactions()))
 	}
-	err := CheckBlockSanity(block, powLimit, timeSource, &wire.SubnetworkIDNative)
+	err = dag.CheckBlockSanity(block, powLimit, timeSource)
 	if err != nil {
 		t.Errorf("CheckBlockSanity: %v", err)
 	}
 	// Test with block with wrong transactions sorting order
 	blockWithWrongTxOrder := util.NewBlock(&BlockWithWrongTxOrder)
-	err = CheckBlockSanity(blockWithWrongTxOrder, powLimit, timeSource, &wire.SubnetworkIDNative)
+	err = dag.CheckBlockSanity(blockWithWrongTxOrder, powLimit, timeSource)
 	if err == nil {
 		t.Errorf("CheckBlockSanity: transactions disorder is not detected")
 	}
@@ -179,7 +190,7 @@ func TestCheckBlockSanity(t *testing.T) {
 	// second fails.
 	timestamp := block.MsgBlock().Header.Timestamp
 	block.MsgBlock().Header.Timestamp = timestamp.Add(time.Nanosecond)
-	err = CheckBlockSanity(block, powLimit, timeSource, &wire.SubnetworkIDNative)
+	err = dag.CheckBlockSanity(block, powLimit, timeSource)
 	if err == nil {
 		t.Errorf("CheckBlockSanity: error is nil when it shouldn't be")
 	}
@@ -445,7 +456,7 @@ func TestCheckBlockSanity(t *testing.T) {
 	}
 
 	btcutilInvalidBlock := util.NewBlock(&invalidParentsOrderBlock)
-	err = CheckBlockSanity(btcutilInvalidBlock, powLimit, timeSource, &wire.SubnetworkIDNative)
+	err = dag.CheckBlockSanity(btcutilInvalidBlock, powLimit, timeSource)
 	if err == nil {
 		t.Errorf("CheckBlockSanity: error is nil when it shouldn't be")
 	}

mempool/mempool.go

@@ -754,7 +754,7 @@ func (mp *TxPool) maybeAcceptTransaction(tx *util.Tx, isNew, rateLimit, rejectDu
 	if msgTx.SubnetworkID == wire.SubnetworkIDSupportsAll {
 		return nil, nil, txRuleError(wire.RejectInvalid, "SubnetworkIDSupportsAll is not permited in transaction")
 	} else if msgTx.SubnetworkID != wire.SubnetworkIDNative {
-		gasLimit, err := mp.cfg.DAG.GasLimit(&msgTx.SubnetworkID)
+		gasLimit, err := mp.cfg.DAG.SubnetworkStore.GasLimit(&msgTx.SubnetworkID)
 		if err != nil {
 			return nil, nil, err
 		}

mining/mining.go

@@ -494,7 +494,7 @@ func (g *BlkTmplGenerator) NewBlockTemplate(payToAddress util.Address) (*BlockTe
 			if !ok {
 				gasUsage = 0
 			}
-			gasLimit, err := g.dag.GasLimit(&subnetworkID)
+			gasLimit, err := g.dag.SubnetworkStore.GasLimit(&subnetworkID)
 			if err != nil {
 				log.Errorf("Cannot get GAS limit for subnetwork %v", subnetworkID)
 				continue

server/rpc/rpcserver.go

@@ -3398,7 +3398,7 @@ func verifyDAG(s *Server, level, depth int32) error {
 	if finishHeight < 0 {
 		finishHeight = 0
 	}
-	log.Infof("Verifying chain for %d blocks at level %d",
+	log.Infof("Verifying DAG for %d blocks at level %d",
 		s.cfg.DAG.Height()-finishHeight, level) //TODO: (Ori) This is probably wrong. Done only for compilation
 
 	currentHash := s.cfg.DAG.HighestTipHash()
@@ -3411,10 +3411,9 @@ func verifyDAG(s *Server, level, depth int32) error {
 			return err
 		}
 
-		// Level 1 does basic chain sanity checks.
+		// Level 1 does basic DAG sanity checks.
 		if level > 0 {
-			err := blockdag.CheckBlockSanity(block, s.cfg.DAGParams.PowLimit,
-				s.cfg.TimeSource, config.MainConfig().SubnetworkID)
+			err := s.cfg.DAG.CheckBlockSanity(block, s.cfg.DAGParams.PowLimit, s.cfg.TimeSource)
 			if err != nil {
 				log.Errorf("Verify is unable to validate "+
 					"block at hash %v height %d: %v",
@@ -3425,7 +3424,7 @@ func verifyDAG(s *Server, level, depth int32) error {
 
 		currentHash = *block.MsgBlock().Header.SelectedParentHash()
 	}
-	log.Infof("Chain verify completed successfully")
+	log.Infof("DAG verify completed successfully")
 
 	return nil
 }