[Issue - #1126] - Checking pruning point violation - pruning point in the past. (#1160)

* [NOD-1126]
1. Change function name in BlockValidator interface from: "ValidateProofOfWorkAndDifficulty" to "ValidatePruningPointViolationAndProofOfWorkAndDifficulty".
2. Add to the blockValidator struct the pruningManager (also added to the function "New" Respectively).
3. Added new function "checkPruningPointViolation" of blockValidator type.
4. Add new internal check - "checkPruningPointViolation", on the function "ValidateProofOfWorkAndDifficulty".(The third check).
5. Add new error rule - "ErrPruningPointViolation".

* [Issue-1126]
1. Remove the function "PruningPoint" from PruningManager interface.
2. Changes in blockValidator struct - remove pruningManager, and adding pruningStore.
3. Reads for "pruningPoint" function from pruningStore instead of pruningManager (because of note 1 above) in the functions: * "checkPruningPointViolation" of type blockValidator.
             * "FindNextPruningPoint" of type pruningManager.

* [Issue-1126]
1. Add missing error handling.

* [Issue-1126] Changes in function "checkPruningPointViolation": If header = genesis, stop checking and return nil.

* [Issue-1126] In function "checkPruningPointViolation" - change from a for loop to the "IsAncestorOfAny" function.

* [#1126] "FindNextPruningPoint" - save the pruning point in case the point is the genesis and change code internal order.

* [#1126] "FindNextPruningPoint" - cosmetics change.

* [#1126] "FindNextPruningPoint" - remove "return nil" when there is no pruning point on the if expression.

Co-authored-by: tal <tal@daglabs.com>

domain/consensus/factory.go

@@ -153,6 +153,7 @@ func (f *factory) NewConsensus(dagParams *dagconfig.Params, db infrastructuredat
 		dagTraversalManager,
 		coinbaseManager,
 		mergeDepthManager,
+		pruningStore,
 
 		blockStore,
 		ghostdagDataStore,

domain/consensus/model/interface_processes_blockvalidator.go

@@ -11,5 +11,5 @@ type BlockValidator interface {
 	ValidateBodyInIsolation(blockHash *externalapi.DomainHash) error
 	ValidateHeaderInContext(blockHash *externalapi.DomainHash) error
 	ValidateBodyInContext(blockHash *externalapi.DomainHash) error
-	ValidateProofOfWorkAndDifficulty(blockHash *externalapi.DomainHash) error
+	ValidatePruningPointViolationAndProofOfWorkAndDifficulty(blockHash *externalapi.DomainHash) error
 }

domain/consensus/model/interface_processes_pruningmanager.go

@@ -1,9 +1,6 @@
 package model
 
-import "github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
-
 // PruningManager resolves and manages the current pruning point
 type PruningManager interface {
 	FindNextPruningPoint() error
-	PruningPoint() (*externalapi.DomainHash, error)
 }

domain/consensus/processes/blockprocessor/validateandinsertblock.go

@@ -240,7 +240,7 @@ func (bp *blockProcessor) validateBlock(block *externalapi.DomainBlock, mode *ex
 		return err
 	}
 
-	err = bp.blockValidator.ValidateProofOfWorkAndDifficulty(blockHash)
+	err = bp.blockValidator.ValidatePruningPointViolationAndProofOfWorkAndDifficulty(blockHash)
 	if err != nil {
 		return err
 	}

domain/consensus/processes/blockvalidator/blockvalidator.go

@@ -28,6 +28,7 @@ type blockValidator struct {
 	dagTraversalManager   model.DAGTraversalManager
 	coinbaseManager       model.CoinbaseManager
 	mergeDepthManager     model.MergeDepthManager
+	pruningStore          model.PruningStore
 
 	blockStore        model.BlockStore
 	ghostdagDataStore model.GHOSTDAGDataStore
@@ -52,6 +53,7 @@ func New(powMax *big.Int,
 	dagTraversalManager model.DAGTraversalManager,
 	coinbaseManager model.CoinbaseManager,
 	mergeDepthManager model.MergeDepthManager,
+	pruningStore model.PruningStore,
 
 	blockStore model.BlockStore,
 	ghostdagDataStore model.GHOSTDAGDataStore,
@@ -75,6 +77,7 @@ func New(powMax *big.Int,
 		dagTraversalManager:            dagTraversalManager,
 		coinbaseManager:                coinbaseManager,
 		mergeDepthManager:              mergeDepthManager,
+		pruningStore:                   pruningStore,
 
 		blockStore:        blockStore,
 		ghostdagDataStore: ghostdagDataStore,

domain/consensus/processes/blockvalidator/proof_of_work.go

@@ -9,7 +9,7 @@ import (
 	"github.com/pkg/errors"
 )
 
-func (v *blockValidator) ValidateProofOfWorkAndDifficulty(blockHash *externalapi.DomainHash) error {
+func (v *blockValidator) ValidatePruningPointViolationAndProofOfWorkAndDifficulty(blockHash *externalapi.DomainHash) error {
 	header, err := v.blockHeaderStore.BlockHeader(v.databaseContext, blockHash)
 	if err != nil {
 		return err
@@ -25,6 +25,11 @@ func (v *blockValidator) ValidateProofOfWorkAndDifficulty(blockHash *externalapi
 		return err
 	}
 
+	err = v.checkPruningPointViolation(header)
+	if err != nil {
+		return err
+	}
+
 	err = v.checkProofOfWork(header)
 	if err != nil {
 		return err
@@ -119,3 +124,31 @@ func (v *blockValidator) checkParentsExist(header *externalapi.DomainBlockHeader
 
 	return nil
 }
+func (v *blockValidator) checkPruningPointViolation(header *externalapi.DomainBlockHeader) error {
+	// check if the pruning point is on past of at least one parent of the header's parents.
+
+	hasPruningPoint, err := v.pruningStore.HasPruningPoint(v.databaseContext)
+	if err != nil {
+		return err
+	}
+
+	//If hasPruningPoint has a false value, it means that it's the genesis - so no violation can exist.
+	if !hasPruningPoint {
+		return nil
+	}
+
+	pruningPoint, err := v.pruningStore.PruningPoint(v.databaseContext)
+	if err != nil {
+		return err
+	}
+
+	isAncestorOfAny, err := v.dagTopologyManager.IsAncestorOfAny(pruningPoint, header.ParentHashes)
+	if err != nil {
+		return err
+	}
+	if isAncestorOfAny {
+		return nil
+	}
+	return errors.Wrapf(ruleerrors.ErrPruningPointViolation,
+		"expected pruning point to be in block %d past.", header.Bits)
+}

domain/consensus/processes/pruningmanager/pruningmanager.go

@@ -73,15 +73,28 @@ func New(
 // FindNextPruningPoint finds the next pruning point from the
 // given blockHash
 func (pm *pruningManager) FindNextPruningPoint() error {
+	hasPruningPoint, err := pm.pruningStore.HasPruningPoint(pm.databaseContext)
+	if err != nil {
+		return err
+	}
+
+	if !hasPruningPoint {
+		err = pm.savePruningPoint(pm.genesisHash)
+		if err != nil {
+			return err
+		}
+	}
+
+	currentP, err := pm.pruningStore.PruningPoint(pm.databaseContext)
+	if err != nil {
+		return err
+	}
+
 	virtual, err := pm.ghostdagDataStore.Get(pm.databaseContext, model.VirtualBlockHash)
 	if err != nil {
 		return err
 	}
 
-	currentP, err := pm.PruningPoint()
-	if err != nil {
-		return err
-	}
 	currentPGhost, err := pm.ghostdagDataStore.Get(pm.databaseContext, currentP)
 	if err != nil {
 		return err
@@ -118,26 +131,6 @@ func (pm *pruningManager) FindNextPruningPoint() error {
 	return pm.deletePastBlocks(currentP)
 }
 
-// PruningPoint returns the hash of the current pruning point
-func (pm *pruningManager) PruningPoint() (*externalapi.DomainHash, error) {
-	hasPruningPoint, err := pm.pruningStore.HasPruningPoint(pm.databaseContext)
-	if err != nil {
-		return nil, err
-	}
-	if hasPruningPoint {
-		return pm.pruningStore.PruningPoint(pm.databaseContext)
-	}
-
-	// If there's no pruning point yet, set genesis as the pruning point.
-	// This is the genesis because it means `FindNextPruningPoint()` has never been called before,
-	// if this is part of the first `FindNextPruningPoint()` call, then it might move the pruning point forward.
-	err = pm.savePruningPoint(pm.genesisHash)
-	if err != nil {
-		return nil, err
-	}
-	return pm.genesisHash, nil
-}
-
 func (pm *pruningManager) deletePastBlocks(pruningPoint *externalapi.DomainHash) error {
 	// Go over all P.Past and P.AC that's not in V.Past
 	queue := pm.dagTraversalManager.NewDownHeap()

domain/consensus/ruleerrors/rule_error.go

@@ -233,6 +233,9 @@ var (
 	ErrMalformedUTXO = newRuleError("ErrMalformedUTXO")
 
 	ErrWrongPruningPointHash = newRuleError("ErrWrongPruningPointHash")
+
+	//ErrPruningPointViolation indicates that the pruning point isn't in the block past.
+	ErrPruningPointViolation = newRuleError("ErrPruningPointViolation")
 )
 
 // RuleError identifies a rule violation. It is used to indicate that