From 2ead9d7d336ce94ff302ae76f2c3c8fc28484445 Mon Sep 17 00:00:00 2001
From: Daniel Van Der Maden <dvandermaden0@berkeley.edu>
Date: Sat, 31 Oct 2020 12:17:27 -0700
Subject: [PATCH] Tx submission epoch checks (#3421)

* [node] Add Cx epoch check

* Report invalid epoch for staking tx

Signed-off-by: Daniel Van Der Maden <dvandermaden0@berkeley.edu>

* [rosetta] Add Cx epoch check in Metadata request

Signed-off-by: Daniel Van Der Maden <dvandermaden0@berkeley.edu>

* [node] Fix lint

Signed-off-by: Daniel Van Der Maden <dvandermaden0@berkeley.edu>
---
 node/node.go                           | 52 +++++++++++++++++---------
 rosetta/services/construction_check.go | 14 +++++++
 2 files changed, 49 insertions(+), 17 deletions(-)

diff --git a/node/node.go b/node/node.go
index 2111fa0ee..59b82aa1a 100644
--- a/node/node.go
+++ b/node/node.go
@@ -204,10 +204,16 @@ func (node *Node) tryBroadcastStaking(stakingTx *staking.StakingTransaction) {
 // Add new transactions to the pending transaction list.
 func (node *Node) addPendingTransactions(newTxs types.Transactions) []error {
 	poolTxs := types.PoolTransactions{}
+	errs := []error{}
+	acceptCx := node.Blockchain().Config().AcceptsCrossTx(node.Blockchain().CurrentHeader().Epoch())
 	for _, tx := range newTxs {
+		if tx.ShardID() != tx.ToShardID() && !acceptCx {
+			errs = append(errs, errors.WithMessage(errInvalidEpoch, "cross-shard tx not accepted yet"))
+			continue
+		}
 		poolTxs = append(poolTxs, tx)
 	}
-	errs := node.TxPool.AddRemotes(poolTxs)
+	errs = append(errs, node.TxPool.AddRemotes(poolTxs)...)
 
 	pendingCount, queueCount := node.TxPool.Stats()
 	utils.Logger().Info().
@@ -221,22 +227,28 @@ func (node *Node) addPendingTransactions(newTxs types.Transactions) []error {
 
 // Add new staking transactions to the pending staking transaction list.
 func (node *Node) addPendingStakingTransactions(newStakingTxs staking.StakingTransactions) []error {
-	if node.NodeConfig.ShardID == shard.BeaconChainShardID &&
-		node.Blockchain().Config().IsPreStaking(node.Blockchain().CurrentHeader().Epoch()) {
-		poolTxs := types.PoolTransactions{}
-		for _, tx := range newStakingTxs {
-			poolTxs = append(poolTxs, tx)
+	if node.NodeConfig.ShardID == shard.BeaconChainShardID {
+		if node.Blockchain().Config().IsPreStaking(node.Blockchain().CurrentHeader().Epoch()) {
+			poolTxs := types.PoolTransactions{}
+			for _, tx := range newStakingTxs {
+				poolTxs = append(poolTxs, tx)
+			}
+			errs := node.TxPool.AddRemotes(poolTxs)
+			pendingCount, queueCount := node.TxPool.Stats()
+			utils.Logger().Info().
+				Int("length of newStakingTxs", len(poolTxs)).
+				Int("totalPending", pendingCount).
+				Int("totalQueued", queueCount).
+				Msg("Got more staking transactions")
+			return errs
 		}
-		errs := node.TxPool.AddRemotes(poolTxs)
-		pendingCount, queueCount := node.TxPool.Stats()
-		utils.Logger().Info().
-			Int("length of newStakingTxs", len(poolTxs)).
-			Int("totalPending", pendingCount).
-			Int("totalQueued", queueCount).
-			Msg("Got more staking transactions")
-		return errs
+		return []error{
+			errors.WithMessage(errInvalidEpoch, "staking txs not accepted yet"),
+		}
+	}
+	return []error{
+		errors.WithMessage(errInvalidShard, fmt.Sprintf("txs only valid on shard %v", shard.BeaconChainShardID)),
 	}
-	return make([]error, len(newStakingTxs))
 }
 
 // AddPendingStakingTransaction staking transactions
@@ -248,13 +260,17 @@ func (node *Node) AddPendingStakingTransaction(
 		var err error
 		for i := range errs {
 			if errs[i] != nil {
-				utils.Logger().Info().Err(errs[i]).Msg("[AddPendingStakingTransaction] Failed adding new staking transaction")
+				utils.Logger().Info().
+					Err(errs[i]).
+					Msg("[AddPendingStakingTransaction] Failed adding new staking transaction")
 				err = errs[i]
 				break
 			}
 		}
 		if err == nil || node.BroadcastInvalidTx {
-			utils.Logger().Info().Str("Hash", newStakingTx.Hash().Hex()).Msg("Broadcasting Staking Tx")
+			utils.Logger().Info().
+				Str("Hash", newStakingTx.Hash().Hex()).
+				Msg("Broadcasting Staking Tx")
 			node.tryBroadcastStaking(newStakingTx)
 		}
 		return err
@@ -361,6 +377,8 @@ var (
 	errWrongShardID      = errors.New("wrong shard id")
 	errInvalidNodeMsg    = errors.New("invalid node message")
 	errIgnoreBeaconMsg   = errors.New("ignore beacon sync block")
+	errInvalidEpoch      = errors.New("invalid epoch for transaction")
+	errInvalidShard      = errors.New("invalid shard")
 )
 
 // validateNodeMessage validate node message
diff --git a/rosetta/services/construction_check.go b/rosetta/services/construction_check.go
index 9b96ea70a..53d1b5f2a 100644
--- a/rosetta/services/construction_check.go
+++ b/rosetta/services/construction_check.go
@@ -172,6 +172,20 @@ func (s *ConstructAPI) ConstructionMetadata(
 		})
 	}
 
+	currBlock, err := s.hmy.BlockByNumber(ctx, ethRpc.LatestBlockNumber)
+	if err != nil {
+		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
+			"message": err.Error(),
+		})
+	}
+
+	if options.OperationType == common.NativeCrossShardTransferOperation &&
+		!s.hmy.BlockChain.Config().AcceptsCrossTx(currBlock.Epoch()) {
+		return nil, common.NewError(common.InvalidTransactionConstructionError, map[string]interface{}{
+			"message": "cross-shard transaction is not accepted yet",
+		})
+	}
+
 	data := hexutil.Bytes{}
 	if options.TransactionMetadata.Data != nil {
 		var err error