consensus: log rejected hashes on CV

Close #4148.

Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>

Author: AnnaShaleva

go.mod

@@ -15,7 +15,7 @@ require (
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/mr-tron/base58 v1.2.0
 	github.com/nspcc-dev/bbolt v0.0.0-20250911202005-807225ebb0c8
-	github.com/nspcc-dev/dbft v0.4.0
+	github.com/nspcc-dev/dbft v0.4.1-0.20260327124130-39ecd4a1a336
 	github.com/nspcc-dev/go-ordered-json v0.0.0-20260302080601-ff7471f924b3
 	github.com/nspcc-dev/neo-go/pkg/interop v0.0.0-20260303143317-87ace720748a
 	github.com/nspcc-dev/neofs-sdk-go v1.0.0-rc.17

go.sum

@@ -151,6 +151,8 @@ github.com/nspcc-dev/bbolt v0.0.0-20250911202005-807225ebb0c8 h1:lYMHisGPtL70vqC
 github.com/nspcc-dev/bbolt v0.0.0-20250911202005-807225ebb0c8/go.mod h1:iYl+DCkSLXgVCeQWyC+kqS9V1fAQCA74JZtptwjNYpc=
 github.com/nspcc-dev/dbft v0.4.0 h1:4/atD4GrrMEtrYBDiZPrPzdKZ6ws7PR/cg0M4DEdVeI=
 github.com/nspcc-dev/dbft v0.4.0/go.mod h1:msYlF5GIGwOZ9jUIHttBAAtiqJ29jzV8PPKKv1avXAI=
+github.com/nspcc-dev/dbft v0.4.1-0.20260327124130-39ecd4a1a336 h1:q8FGMjSqskV1Qt/M/9+Oki8wu8yHw+OuOViNAHiHosc=
+github.com/nspcc-dev/dbft v0.4.1-0.20260327124130-39ecd4a1a336/go.mod h1:wlDUe85rc9UVf4ojolXJ5mml1O/B1VFz4oGOE0Acc2E=
 github.com/nspcc-dev/go-ordered-json v0.0.0-20260302080601-ff7471f924b3 h1:txQ9PnyK2SW8aLmQMatGDDeZqQX8XdslrMnbcptmW5A=
 github.com/nspcc-dev/go-ordered-json v0.0.0-20260302080601-ff7471f924b3/go.mod h1:LtSGm9lKJLWHnB9w4q0ZPfA9bvt/D3FZcm2vHmbsfxQ=
 github.com/nspcc-dev/hrw/v2 v2.0.4 h1:o3Zh/2aF+IgGpvt414f46Ya20WG9u9vWxVd16ErFI8w=

pkg/consensus/change_view.go

@@ -3,13 +3,15 @@ package consensus
 import (
 	"github.com/nspcc-dev/dbft"
 	"github.com/nspcc-dev/neo-go/pkg/io"
+	"github.com/nspcc-dev/neo-go/pkg/util"
 )
 
 // changeView represents dBFT ChangeView message.
 type changeView struct {
-	newViewNumber byte
-	timestamp     uint64
-	reason        dbft.ChangeViewReason
+	newViewNumber  byte
+	timestamp      uint64
+	reason         dbft.ChangeViewReason
+	rejectedHashes []util.Uint256
 }
 
 var _ dbft.ChangeView = (*changeView)(nil)
@@ -18,12 +20,18 @@ var _ dbft.ChangeView = (*changeView)(nil)
 func (c *changeView) EncodeBinary(w *io.BinWriter) {
 	w.WriteU64LE(c.timestamp)
 	w.WriteB(byte(c.reason))
+	if c.reason == dbft.CVTxInvalid || c.reason == dbft.CVTxRejectedByPolicy {
+		w.WriteArray(c.rejectedHashes)
+	}
 }
 
 // DecodeBinary implements the io.Serializable interface.
 func (c *changeView) DecodeBinary(r *io.BinReader) {
 	c.timestamp = r.ReadU64LE()
 	c.reason = dbft.ChangeViewReason(r.ReadB())
+	if c.reason == dbft.CVTxInvalid || c.reason == dbft.CVTxRejectedByPolicy {
+		r.ReadArray(&c.rejectedHashes)
+	}
 }
 
 // NewViewNumber implements the payload.ChangeView interface.

pkg/consensus/consensus.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"slices"
+	"strings"
 	"sync/atomic"
 	"time"
 
@@ -270,11 +271,16 @@ func (s *service) newPrepareResponse(preparationHash util.Uint256) dbft.PrepareR
 	}
 }
 
-func (s *service) newChangeView(newViewNumber byte, reason dbft.ChangeViewReason, ts uint64) dbft.ChangeView {
+func (s *service) newChangeView(newViewNumber byte, reason dbft.ChangeViewReason, ts uint64, rejectedH ...util.Uint256) dbft.ChangeView {
+	var rejected []util.Uint256
+	if len(rejectedH) > 0 {
+		rejected = append(rejected, rejectedH...)
+	}
 	return &changeView{
-		newViewNumber: newViewNumber,
-		timestamp:     ts / nsInMs,
-		reason:        reason,
+		newViewNumber:  newViewNumber,
+		timestamp:      ts / nsInMs,
+		reason:         reason,
+		rejectedHashes: rejected,
 	}
 }
 
@@ -359,7 +365,9 @@ events:
 				zap.Stringer("type", msg.Type()),
 			}
 
-			if msg.Type() == dbft.RecoveryMessageType {
+			log := s.log.Debug
+			switch msg.Type() {
+			case dbft.RecoveryMessageType:
 				rec := msg.GetRecoveryMessage().(*recoveryMessage)
 				if rec.preparationHash == nil {
 					req := rec.GetPrepareRequest(&msg, s.dbft.Validators, uint16(s.dbft.PrimaryIndex))
@@ -375,9 +383,23 @@ events:
 					zap.Int("#changeview", len(rec.changeViewPayloads)),
 					zap.Bool("#request", rec.prepareRequest != nil),
 					zap.Bool("#hash", rec.preparationHash != nil))
+			case dbft.ChangeViewType:
+				cv := msg.GetChangeView().(*changeView)
+				if len(cv.rejectedHashes) > 0 {
+					const maxHashes = 10
+					var rejected strings.Builder
+					log = s.log.Warn
+					for _, h := range cv.rejectedHashes[:min(len(cv.rejectedHashes), maxHashes)] { // don't pollute logs with too many hashes.
+						fmt.Fprintf(&rejected, "%s ", h.StringLE())
+					}
+					if len(cv.rejectedHashes) > maxHashes {
+						rejected.WriteString("...")
+					}
+					fields = append(fields, zap.String("rejected", rejected.String()))
+				}
 			}
 
-			s.log.Debug("received message", fields...)
+			log("received message", fields...)
 			s.dbft.OnReceive(&msg)
 		case tx := <-s.transactions:
 			s.dbft.OnTransaction(tx)
@@ -525,26 +547,26 @@ func (s *service) getTx(h util.Uint256) dbft.Transaction[util.Uint256] {
 	return nil
 }
 
-func (s *service) verifyBlock(b dbft.Block[util.Uint256]) bool {
+func (s *service) verifyBlock(b dbft.Block[util.Uint256]) (bool, util.Uint256) {
 	coreb := &b.(*neoBlock).Block
 
 	if s.Chain.BlockHeight() >= coreb.Index {
 		s.log.Warn("proposed block has already outdated")
-		return false
+		return false, util.Uint256{}
 	}
 	if s.lastTimestamp >= coreb.Timestamp {
 		s.log.Warn("proposed block has small timestamp",
 			zap.Uint64("ts", coreb.Timestamp),
 			zap.Uint64("last", s.lastTimestamp))
-		return false
+		return false, util.Uint256{}
 	}
 
 	size := coreb.GetExpectedBlockSize()
 	if size > int(s.ProtocolConfiguration.MaxBlockSize) {
 		s.log.Warn("proposed block size exceeds config MaxBlockSize",
 			zap.Uint32("max size allowed", s.ProtocolConfiguration.MaxBlockSize),
 			zap.Int("block size", size))
-		return false
+		return false, util.Uint256{}
 	}
 
 	var fee int64
@@ -566,11 +588,11 @@ func (s *service) verifyBlock(b dbft.Block[util.Uint256]) bool {
 			s.log.Warn("invalid transaction in proposed block",
 				zap.Stringer("hash", tx.Hash()),
 				zap.Error(err))
-			return false
+			return false, tx.Hash()
 		}
 		if s.Chain.BlockHeight() >= coreb.Index {
 			s.log.Warn("proposed block has already outdated")
-			return false
+			return false, util.Uint256{}
 		}
 	}
 
@@ -579,10 +601,10 @@ func (s *service) verifyBlock(b dbft.Block[util.Uint256]) bool {
 		s.log.Warn("proposed block system fee exceeds config MaxBlockSystemFee",
 			zap.Int("max system fee allowed", int(maxBlockSysFee)),
 			zap.Int("block system fee", int(fee)))
-		return false
+		return false, util.Uint256{}
 	}
 
-	return true
+	return true, util.Uint256{}
 }
 
 var (

pkg/consensus/consensus_test.go

@@ -397,7 +397,8 @@ func TestVerifyBlock(t *testing.T) {
 	srv.lastTimestamp = 1
 	t.Run("good empty", func(t *testing.T) {
 		b := testchain.NewBlock(t, bc, 1, 0)
-		require.True(t, srv.verifyBlock(&neoBlock{Block: *b}))
+		ok, _ := srv.verifyBlock(&neoBlock{Block: *b})
+		require.True(t, ok)
 	})
 	t.Run("good pooled tx", func(t *testing.T) {
 		tx := transaction.New([]byte{byte(opcode.RET)}, 100000)
@@ -406,15 +407,17 @@ func TestVerifyBlock(t *testing.T) {
 		signTx(t, srv.Chain, tx)
 		require.NoError(t, srv.Chain.PoolTx(tx))
 		b := testchain.NewBlock(t, bc, 1, 0, tx)
-		require.True(t, srv.verifyBlock(&neoBlock{Block: *b}))
+		ok, _ := srv.verifyBlock(&neoBlock{Block: *b})
+		require.True(t, ok)
 	})
 	t.Run("good non-pooled tx", func(t *testing.T) {
 		tx := transaction.New([]byte{byte(opcode.RET)}, 100000)
 		tx.ValidUntilBlock = 1
 		addSender(t, tx)
 		signTx(t, srv.Chain, tx)
 		b := testchain.NewBlock(t, bc, 1, 0, tx)
-		require.True(t, srv.verifyBlock(&neoBlock{Block: *b}))
+		ok, _ := srv.verifyBlock(&neoBlock{Block: *b})
+		require.True(t, ok)
 	})
 	t.Run("good conflicting tx", func(t *testing.T) {
 		initGAS := srv.Chain.GetConfig().InitialGASSupply
@@ -431,12 +434,14 @@ func TestVerifyBlock(t *testing.T) {
 		require.NoError(t, srv.Chain.PoolTx(tx1))
 		require.Error(t, srv.Chain.PoolTx(tx2))
 		b := testchain.NewBlock(t, bc, 1, 0, tx2)
-		require.True(t, srv.verifyBlock(&neoBlock{Block: *b}))
+		ok, _ := srv.verifyBlock(&neoBlock{Block: *b})
+		require.True(t, ok)
 	})
 	t.Run("bad old", func(t *testing.T) {
 		b := testchain.NewBlock(t, bc, 1, 0)
 		b.Index = srv.Chain.BlockHeight()
-		require.False(t, srv.verifyBlock(&neoBlock{Block: *b}))
+		ok, _ := srv.verifyBlock(&neoBlock{Block: *b})
+		require.False(t, ok)
 	})
 	t.Run("bad big size", func(t *testing.T) {
 		script := make([]byte, int(srv.ProtocolConfiguration.MaxBlockSize))
@@ -446,12 +451,14 @@ func TestVerifyBlock(t *testing.T) {
 		addSender(t, tx)
 		signTx(t, srv.Chain, tx)
 		b := testchain.NewBlock(t, bc, 1, 0, tx)
-		require.False(t, srv.verifyBlock(&neoBlock{Block: *b}))
+		ok, _ := srv.verifyBlock(&neoBlock{Block: *b})
+		require.False(t, ok)
 	})
 	t.Run("bad timestamp", func(t *testing.T) {
 		b := testchain.NewBlock(t, bc, 1, 0)
 		b.Timestamp = srv.lastTimestamp - 1
-		require.False(t, srv.verifyBlock(&neoBlock{Block: *b}))
+		ok, _ := srv.verifyBlock(&neoBlock{Block: *b})
+		require.False(t, ok)
 	})
 	t.Run("bad tx", func(t *testing.T) {
 		tx := transaction.New([]byte{byte(opcode.RET)}, 100000)
@@ -460,7 +467,9 @@ func TestVerifyBlock(t *testing.T) {
 		signTx(t, srv.Chain, tx)
 		tx.Scripts[0].InvocationScript[16] = ^tx.Scripts[0].InvocationScript[16]
 		b := testchain.NewBlock(t, bc, 1, 0, tx)
-		require.False(t, srv.verifyBlock(&neoBlock{Block: *b}))
+		ok, rejected := srv.verifyBlock(&neoBlock{Block: *b})
+		require.False(t, ok)
+		require.Equal(t, rejected, tx.Hash())
 	})
 	t.Run("bad big sys fee", func(t *testing.T) {
 		txes := make([]*transaction.Transaction, 2)
@@ -471,7 +480,8 @@ func TestVerifyBlock(t *testing.T) {
 			signTx(t, srv.Chain, txes[i])
 		}
 		b := testchain.NewBlock(t, bc, 1, 0, txes...)
-		require.False(t, srv.verifyBlock(&neoBlock{Block: *b}))
+		ok, _ := srv.verifyBlock(&neoBlock{Block: *b})
+		require.False(t, ok)
 	})
 }