feat: give the application control to validate the app version

proto/tendermint/abci/types.proto

@@ -147,6 +147,7 @@ message RequestProcessProposal {
   bytes                     next_validators_hash = 7;
   // address of the public key of the original proposer of the block.
   bytes proposer_address = 8;
+  uint64 app_version = 9;
 }
 
 //----------------------------------------

state/execution.go

@@ -179,6 +179,7 @@ func (blockExec *BlockExecutor) ProcessProposal(
 		Misbehavior:        block.Evidence.Evidence.ToABCI(),
 		ProposerAddress:    block.ProposerAddress,
 		NextValidatorsHash: block.NextValidatorsHash,
+		AppVersion:         block.Header.Version.App,
 	})
 	if err != nil {
 		return false, ErrInvalidBlock(err)

state/validation.go

@@ -18,12 +18,12 @@ func validateBlock(state State, block *types.Block) error {
 		return err
 	}
 
-	// Validate basic info.
-	if block.Version.App != state.Version.Consensus.App ||
-		block.Version.Block != state.Version.Consensus.Block {
+	// Validate block version. App version validation should
+	// happen on the application side as part of process proposal
+	if block.Version.Block != state.Version.Consensus.Block {
 		return fmt.Errorf("wrong Block.Header.Version. Expected %v, got %v",
-			state.Version.Consensus,
-			block.Version,
+			state.Version.Consensus.Block,
+			block.Version.Block,
 		)
 	}
 	if block.ChainID != state.ChainID {

state/validation_test.go

@@ -45,16 +45,13 @@ func TestValidateBlockHeader(t *testing.T) {
 	wrongHash := tmhash.Sum([]byte("this hash is wrong"))
 	wrongVersion1 := state.Version.Consensus
 	wrongVersion1.Block += 2
-	wrongVersion2 := state.Version.Consensus
-	wrongVersion2.App += 2
 
 	// Manipulation of any header field causes failure.
 	testCases := []struct {
 		name          string
 		malleateBlock func(block *types.Block)
 	}{
 		{"Version wrong1", func(block *types.Block) { block.Version = wrongVersion1 }},
-		{"Version wrong2", func(block *types.Block) { block.Version = wrongVersion2 }},
 		{"ChainID wrong", func(block *types.Block) { block.ChainID = "not-the-real-one" }},
 		{"Height wrong", func(block *types.Block) { block.Height += 10 }},
 		{"Time wrong", func(block *types.Block) { block.Time = block.Time.Add(-time.Second * 1) }},

statesync/syncer.go

@@ -306,7 +306,7 @@ func (s *syncer) Sync(snapshot *snapshot, chunks *chunkQueue) (sm.State, *types.
 	}
 
 	// Verify app and app version
-	if err := s.verifyApp(snapshot, state.Version.Consensus.App); err != nil {
+	if err := s.verifyApp(snapshot); err != nil {
 		return sm.State{}, nil, err
 	}
 
@@ -482,20 +482,12 @@ func (s *syncer) requestChunk(snapshot *snapshot, chunk uint32) {
 }
 
 // verifyApp verifies the sync, checking the app hash, last block height and app version
-func (s *syncer) verifyApp(snapshot *snapshot, appVersion uint64) error {
+func (s *syncer) verifyApp(snapshot *snapshot) error {
 	resp, err := s.connQuery.InfoSync(proxy.RequestInfo)
 	if err != nil {
 		return fmt.Errorf("failed to query ABCI app for appHash: %w", err)
 	}
 
-	// sanity check that the app version in the block matches the application's own record
-	// of its version
-	if resp.AppVersion != appVersion {
-		// An error here most likely means that the app hasn't inplemented state sync
-		// or the Info call correctly
-		return fmt.Errorf("app version mismatch. Expected: %d, got: %d",
-			appVersion, resp.AppVersion)
-	}
 	if !bytes.Equal(snapshot.trustedAppHash, resp.LastBlockAppHash) {
 		s.logger.Error("appHash verification failed",
 			"expected", snapshot.trustedAppHash,

statesync/syncer_test.go

@@ -634,7 +634,6 @@ func TestSyncer_applyChunks_RejectSenders(t *testing.T) {
 func TestSyncer_verifyApp(t *testing.T) {
 	boom := errors.New("boom")
 	const appVersion = 9
-	appVersionMismatchErr := errors.New("app version mismatch. Expected: 9, got: 2")
 	s := &snapshot{Height: 3, Format: 1, Chunks: 5, Hash: []byte{1, 2, 3}, trustedAppHash: []byte("app_hash")}
 
 	testcases := map[string]struct {
@@ -647,11 +646,6 @@ func TestSyncer_verifyApp(t *testing.T) {
 			LastBlockAppHash: []byte("app_hash"),
 			AppVersion:       appVersion,
 		}, nil, nil},
-		"invalid app version": {&abci.ResponseInfo{
-			LastBlockHeight:  3,
-			LastBlockAppHash: []byte("app_hash"),
-			AppVersion:       2,
-		}, nil, appVersionMismatchErr},
 		"invalid height": {&abci.ResponseInfo{
 			LastBlockHeight:  5,
 			LastBlockAppHash: []byte("app_hash"),
@@ -675,7 +669,7 @@ func TestSyncer_verifyApp(t *testing.T) {
 			syncer := newSyncer(*cfg, log.NewNopLogger(), connSnapshot, connQuery, stateProvider, "")
 
 			connQuery.On("InfoSync", proxy.RequestInfo).Return(tc.response, tc.err)
-			err := syncer.verifyApp(s, appVersion)
+			err := syncer.verifyApp(s)
 			unwrapped := errors.Unwrap(err)
 			if unwrapped != nil {
 				err = unwrapped