Disallow header only blocks on RPC, relay and when requesting IBD full blocks (#1537)

app/protocol/flowcontext/blocks.go

@@ -2,6 +2,7 @@ package flowcontext
 
 import (
 	peerpkg "github.com/kaspanet/kaspad/app/protocol/peer"
+	"github.com/kaspanet/kaspad/app/protocol/protocolerrors"
 	"github.com/kaspanet/kaspad/domain/consensus/ruleerrors"
 	"github.com/pkg/errors"
 
@@ -98,6 +99,10 @@ func (f *FlowContext) SharedRequestedBlocks() *blockrelay.SharedRequestedBlocks
 
 // AddBlock adds the given block to the DAG and propagates it.
 func (f *FlowContext) AddBlock(block *externalapi.DomainBlock) error {
+	if len(block.Transactions) == 0 {
+		return protocolerrors.Errorf(false, "cannot add header only block")
+	}
+
 	blockInsertionResult, err := f.Domain().Consensus().ValidateAndInsertBlock(block)
 	if err != nil {
 		if errors.As(err, &ruleerrors.RuleError{}) {

app/protocol/flows/blockrelay/handle_relay_invs.go

@@ -104,6 +104,11 @@ func (flow *handleRelayInvsFlow) start() error {
 			continue
 		}
 
+		err = flow.banIfBlockIsHeaderOnly(block)
+		if err != nil {
+			return err
+		}
+
 		log.Debugf("Processing block %s", inv.Hash)
 		missingParents, blockInsertionResult, err := flow.processBlock(block)
 		if err != nil {
@@ -140,6 +145,15 @@ func (flow *handleRelayInvsFlow) start() error {
 	}
 }
 
+func (flow *handleRelayInvsFlow) banIfBlockIsHeaderOnly(block *externalapi.DomainBlock) error {
+	if len(block.Transactions) == 0 {
+		return protocolerrors.Errorf(true, "sent header of %s block where expected block with body",
+			consensushashing.BlockHash(block))
+	}
+
+	return nil
+}
+
 func (flow *handleRelayInvsFlow) readInv() (*appmessage.MsgInvRelayBlock, error) {
 	if len(flow.invsQueue) > 0 {
 		var inv *appmessage.MsgInvRelayBlock

app/protocol/flows/blockrelay/ibd.go

@@ -533,6 +533,11 @@ func (flow *handleRelayInvsFlow) syncMissingBlockBodies(highHash *externalapi.Do
 				return protocolerrors.Errorf(true, "expected block %s but got %s", expectedHash, blockHash)
 			}
 
+			err = flow.banIfBlockIsHeaderOnly(block)
+			if err != nil {
+				return err
+			}
+
 			blockInsertionResult, err := flow.Domain().Consensus().ValidateAndInsertBlock(block)
 			if err != nil {
 				if errors.Is(err, ruleerrors.ErrDuplicateBlock) {

app/protocol/flows/testing/handle_relay_invs_test.go

@@ -24,6 +24,19 @@ import (
 	"github.com/pkg/errors"
 )
 
+var headerOnlyBlock = &externalapi.DomainBlock{
+	Header: blockheader.NewImmutableBlockHeader(
+		constants.MaxBlockVersion,
+		[]*externalapi.DomainHash{externalapi.NewDomainHashFromByteArray(&[externalapi.DomainHashSize]byte{1})},
+		&externalapi.DomainHash{},
+		&externalapi.DomainHash{},
+		&externalapi.DomainHash{},
+		0,
+		0,
+		0,
+	),
+}
+
 var orphanBlock = &externalapi.DomainBlock{
 	Header: blockheader.NewImmutableBlockHeader(
 		constants.MaxBlockVersion,
@@ -35,6 +48,7 @@ var orphanBlock = &externalapi.DomainBlock{
 		0,
 		0,
 	),
+	Transactions: []*externalapi.DomainTransaction{{}},
 }
 
 var validPruningPointBlock = &externalapi.DomainBlock{
@@ -48,6 +62,7 @@ var validPruningPointBlock = &externalapi.DomainBlock{
 		0,
 		0,
 	),
+	Transactions: []*externalapi.DomainTransaction{{}},
 }
 
 var invalidPruningPointBlock = &externalapi.DomainBlock{
@@ -61,6 +76,7 @@ var invalidPruningPointBlock = &externalapi.DomainBlock{
 		0,
 		0,
 	),
+	Transactions: []*externalapi.DomainTransaction{{}},
 }
 
 var unexpectedIBDBlock = &externalapi.DomainBlock{
@@ -74,6 +90,7 @@ var unexpectedIBDBlock = &externalapi.DomainBlock{
 		0,
 		0,
 	),
+	Transactions: []*externalapi.DomainTransaction{{}},
 }
 
 var invalidBlock = &externalapi.DomainBlock{
@@ -87,6 +104,7 @@ var invalidBlock = &externalapi.DomainBlock{
 		0,
 		0,
 	),
+	Transactions: []*externalapi.DomainTransaction{{}},
 }
 
 var unknownBlockHash = externalapi.NewDomainHashFromByteArray(&[externalapi.DomainHashSize]byte{1})
@@ -95,6 +113,7 @@ var validPruningPointHash = consensushashing.BlockHash(validPruningPointBlock)
 var invalidBlockHash = consensushashing.BlockHash(invalidBlock)
 var invalidPruningPointHash = consensushashing.BlockHash(invalidPruningPointBlock)
 var orphanBlockHash = consensushashing.BlockHash(orphanBlock)
+var headerOnlyBlockHash = consensushashing.BlockHash(headerOnlyBlock)
 
 type fakeRelayInvsContext struct {
 	testName             string
@@ -450,6 +469,29 @@ func TestHandleRelayInvs(t *testing.T) {
 			expectsBan:           true,
 			expectsErrToContain:  "got unrequested block",
 		},
+		{
+			name: "sending header only block on relay",
+			funcToExecute: func(t *testing.T, incomingRoute, outgoingRoute *router.Route, context *fakeRelayInvsContext) {
+				err := incomingRoute.Enqueue(appmessage.NewMsgInvBlock(headerOnlyBlockHash))
+				if err != nil {
+					t.Fatalf("Enqueue: %+v", err)
+				}
+
+				msg, err := outgoingRoute.DequeueWithTimeout(time.Second)
+				if err != nil {
+					t.Fatalf("DequeueWithTimeout: %+v", err)
+				}
+				_ = msg.(*appmessage.MsgRequestRelayBlocks)
+
+				err = incomingRoute.Enqueue(appmessage.DomainBlockToMsgBlock(headerOnlyBlock))
+				if err != nil {
+					t.Fatalf("Enqueue: %+v", err)
+				}
+			},
+			expectsProtocolError: true,
+			expectsBan:           true,
+			expectsErrToContain:  "block where expected block with body",
+		},
 		{
 			name: "sending invalid block",
 			funcToExecute: func(t *testing.T, incomingRoute, outgoingRoute *router.Route, context *fakeRelayInvsContext) {

app/rpc/rpchandlers/submit_block.go

@@ -2,6 +2,7 @@ package rpchandlers
 
 import (
 	"github.com/kaspanet/kaspad/app/appmessage"
+	"github.com/kaspanet/kaspad/app/protocol/protocolerrors"
 	"github.com/kaspanet/kaspad/app/rpc/rpccontext"
 	"github.com/kaspanet/kaspad/domain/consensus/ruleerrors"
 	"github.com/kaspanet/kaspad/domain/consensus/utils/consensushashing"
@@ -25,9 +26,10 @@ func HandleSubmitBlock(context *rpccontext.Context, _ *router.Router, request ap
 
 	err := context.ProtocolManager.AddBlock(domainBlock)
 	if err != nil {
-		if !errors.As(err, &ruleerrors.RuleError{}) {
+		if !errors.As(err, &ruleerrors.RuleError{}) || !errors.As(err, &protocolerrors.ProtocolError{}) {
 			return nil, err
 		}
+
 		return &appmessage.SubmitBlockResponseMessage{
 			Error:        appmessage.RPCErrorf("Block rejected. Reason: %s", err),
 			RejectReason: appmessage.RejectReasonBlockInvalid,