add defensive check for minimum GasFeeCap for inclusion within the next 20 blocks

chain/messagepool/messagepool.go

@@ -11,7 +11,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/filecoin-project/specs-actors/actors/abi"
 	"github.com/filecoin-project/specs-actors/actors/crypto"
 	"github.com/hashicorp/go-multierror"
 	lru "github.com/hashicorp/golang-lru"
@@ -49,6 +48,7 @@ const RbfDenom = 256
 var RepublishInterval = pubsub.TimeCacheDuration + time.Duration(5*build.BlockDelaySecs+build.PropagationDelaySecs)*time.Second
 
 var minimumBaseFee = types.NewInt(uint64(build.MinimumBaseFee))
+var baseFeeLowerBoundFactor = types.NewInt(10)
 
 var MaxActorPendingMessages = 1000
 
@@ -355,12 +355,30 @@ func (mp *MessagePool) addLocal(m *types.SignedMessage, msgb []byte) error {
 	return nil
 }
 
-func (mp *MessagePool) verifyMsgBeforeAdd(m *types.SignedMessage, epoch abi.ChainEpoch) error {
+func (mp *MessagePool) verifyMsgBeforeAdd(m *types.SignedMessage, curTs *types.TipSet, local bool) error {
+	epoch := curTs.Height()
 	minGas := vm.PricelistByEpoch(epoch).OnChainMessage(m.ChainLength())
 
 	if err := m.VMMessage().ValidForBlockInclusion(minGas.Total()); err != nil {
 		return xerrors.Errorf("message will not be included in a block: %w", err)
 	}
+
+	// this checks if the GasFeeCap is suffisciently high for inclusion in the next 20 blocks
+	// if the GasFeeCap is too low, we soft reject the message (Ignore in pubsub) and rely
+	// on republish to push it through later, if the baseFee has fallen.
+	// this is a defensive check that stops minimum baseFee spam attacks from overloading validation
+	// queues.
+	// Note that we don't do that for local messages, so that they can be accepted and republished
+	// automatically
+	if !local && len(curTs.Blocks()) > 0 {
+		baseFee := curTs.Blocks()[0].ParentBaseFee
+		baseFeeLowerBound := types.BigDiv(baseFee, baseFeeLowerBoundFactor)
+		if m.Message.GasFeeCap.LessThan(baseFeeLowerBound) {
+			return xerrors.Errorf("GasFeeCap doesn't meet base fee lower bound for inclusion in the next 20 blocks (GasFeeCap: %s, baseFeeLowerBound: %s): %w",
+				m.Message.GasFeeCap, baseFeeLowerBound, ErrSoftValidationFailure)
+		}
+	}
+
 	return nil
 }
 
@@ -382,7 +400,7 @@ func (mp *MessagePool) Push(m *types.SignedMessage) (cid.Cid, error) {
 	}
 
 	mp.curTsLk.Lock()
-	if err := mp.addTs(m, mp.curTs); err != nil {
+	if err := mp.addTs(m, mp.curTs, true); err != nil {
 		mp.curTsLk.Unlock()
 		return cid.Undef, err
 	}
@@ -443,7 +461,7 @@ func (mp *MessagePool) Add(m *types.SignedMessage) error {
 
 	mp.curTsLk.Lock()
 	defer mp.curTsLk.Unlock()
-	return mp.addTs(m, mp.curTs)
+	return mp.addTs(m, mp.curTs, false)
 }
 
 func sigCacheKey(m *types.SignedMessage) (string, error) {
@@ -510,7 +528,7 @@ func (mp *MessagePool) checkBalance(m *types.SignedMessage, curTs *types.TipSet)
 	return nil
 }
 
-func (mp *MessagePool) addTs(m *types.SignedMessage, curTs *types.TipSet) error {
+func (mp *MessagePool) addTs(m *types.SignedMessage, curTs *types.TipSet, local bool) error {
 	snonce, err := mp.getStateNonce(m.Message.From, curTs)
 	if err != nil {
 		return xerrors.Errorf("failed to look up actor state nonce: %s: %w", err, ErrSoftValidationFailure)
@@ -523,7 +541,7 @@ func (mp *MessagePool) addTs(m *types.SignedMessage, curTs *types.TipSet) error
 	mp.lk.Lock()
 	defer mp.lk.Unlock()
 
-	if err := mp.verifyMsgBeforeAdd(m, curTs.Height()); err != nil {
+	if err := mp.verifyMsgBeforeAdd(m, curTs, local); err != nil {
 		return err
 	}
 
@@ -557,7 +575,7 @@ func (mp *MessagePool) addLoaded(m *types.SignedMessage) error {
 	mp.lk.Lock()
 	defer mp.lk.Unlock()
 
-	if err := mp.verifyMsgBeforeAdd(m, curTs.Height()); err != nil {
+	if err := mp.verifyMsgBeforeAdd(m, curTs, true); err != nil {
 		return err
 	}
 
@@ -743,7 +761,7 @@ func (mp *MessagePool) PushWithNonce(ctx context.Context, addr address.Address,
 		return nil, ErrTryAgain
 	}
 
-	if err := mp.verifyMsgBeforeAdd(msg, curTs.Height()); err != nil {
+	if err := mp.verifyMsgBeforeAdd(msg, curTs, true); err != nil {
 		return nil, err
 	}
 

chain/types/mock/chain.go

@@ -9,6 +9,7 @@ import (
 	"github.com/filecoin-project/specs-actors/actors/crypto"
 	"github.com/ipfs/go-cid"
 
+	"github.com/filecoin-project/lotus/build"
 	"github.com/filecoin-project/lotus/chain/types"
 	"github.com/filecoin-project/lotus/chain/wallet"
 )
@@ -80,6 +81,7 @@ func MkBlock(parents *types.TipSet, weightInc uint64, ticketNonce uint64) *types
 		Height:                height,
 		ParentStateRoot:       pstateRoot,
 		BlockSig:              &crypto.Signature{Type: crypto.SigTypeBLS, Data: []byte("boo! im a signature")},
+		ParentBaseFee:         types.NewInt(uint64(build.MinimumBaseFee)),
 	}
 }