internal/ethapi: add mutex around signing + nonce assignment

This prevents concurrent assignment of identical nonces when automatic
assignment is used.

internal/ethapi/api.go

@@ -23,7 +23,6 @@ import (
 	"fmt"
 	"math/big"
 	"strings"
-	"sync"
 	"time"
 
 	"github.com/ethereum/go-ethereum/accounts"
@@ -204,12 +203,13 @@ func (s *PublicAccountAPI) Accounts() []common.Address {
 // It offers methods to create, (un)lock en list accounts. Some methods accept
 // passwords and are therefore considered private by default.
 type PrivateAccountAPI struct {
-	am *accounts.Manager
-	b  Backend
+	am        *accounts.Manager
+	nonceLock *AddrLocker
+	b         Backend
 }
 
 // NewPrivateAccountAPI create a new PrivateAccountAPI.
-func NewPrivateAccountAPI(b Backend) *PrivateAccountAPI {
+func NewPrivateAccountAPI(b Backend, nonceLock *AddrLocker) *PrivateAccountAPI {
 	return &PrivateAccountAPI{
 		am: b.AccountManager(),
 		b:  b,
@@ -316,10 +316,6 @@ func (s *PrivateAccountAPI) LockAccount(addr common.Address) bool {
 // tries to sign it with the key associated with args.To. If the given passwd isn't
 // able to decrypt the key it fails.
 func (s *PrivateAccountAPI) SendTransaction(ctx context.Context, args SendTxArgs, passwd string) (common.Hash, error) {
-	// Set some sanity defaults and terminate on failure
-	if err := args.setDefaults(ctx, s.b); err != nil {
-		return common.Hash{}, err
-	}
 	// Look up the wallet containing the requested signer
 	account := accounts.Account{Address: args.From}
 
@@ -327,6 +323,18 @@ func (s *PrivateAccountAPI) SendTransaction(ctx context.Context, args SendTxArgs
 	if err != nil {
 		return common.Hash{}, err
 	}
+
+	if args.Nonce == nil {
+		// Hold the addresse's mutex around signing to prevent concurrent assignment of
+		// the same nonce to multiple accounts.
+		s.nonceLock.LockAddr(args.From)
+		defer s.nonceLock.UnlockAddr(args.From)
+	}
+
+	// Set some sanity defaults and terminate on failure
+	if err := args.setDefaults(ctx, s.b); err != nil {
+		return common.Hash{}, err
+	}
 	// Assemble the transaction and sign with the wallet
 	tx := args.toTransaction()
 
@@ -886,18 +894,13 @@ func newRPCTransaction(b *types.Block, txHash common.Hash) (*RPCTransaction, err
 
 // PublicTransactionPoolAPI exposes methods for the RPC interface
 type PublicTransactionPoolAPI struct {
-	b Backend
+	b         Backend
+	nonceLock *AddrLocker
 }
 
-// nonceMutex is a global mutex for locking the nonce while a transaction
-// is being submitted. This should be used when a nonce has not been provided by the user,
-// and we get a nonce from the pools. The mutex prevents the (an identical nonce) from being
-// read again during the time that the first transaction is being signed.
-var nonceMutex sync.RWMutex
-
 // NewPublicTransactionPoolAPI creates a new RPC service with methods specific for the transaction pool.
-func NewPublicTransactionPoolAPI(b Backend) *PublicTransactionPoolAPI {
-	return &PublicTransactionPoolAPI{b}
+func NewPublicTransactionPoolAPI(b Backend, nonceLock *AddrLocker) *PublicTransactionPoolAPI {
+	return &PublicTransactionPoolAPI{b, nonceLock}
 }
 
 func getTransaction(chainDb ethdb.Database, b Backend, txHash common.Hash) (*types.Transaction, bool, error) {
@@ -1176,17 +1179,6 @@ func submitTransaction(ctx context.Context, b Backend, tx *types.Transaction) (c
 // transaction pool.
 func (s *PublicTransactionPoolAPI) SendTransaction(ctx context.Context, args SendTxArgs) (common.Hash, error) {
 
-	if args.Nonce == nil {
-		// We'll need to set nonce from pool, and thus we need to lock here
-		nonceMutex.Lock()
-		defer nonceMutex.Unlock()
-
-	}
-
-	// Set some sanity defaults and terminate on failure
-	if err := args.setDefaults(ctx, s.b); err != nil {
-		return common.Hash{}, err
-	}
 	// Look up the wallet containing the requested signer
 	account := accounts.Account{Address: args.From}
 
@@ -1194,6 +1186,18 @@ func (s *PublicTransactionPoolAPI) SendTransaction(ctx context.Context, args Sen
 	if err != nil {
 		return common.Hash{}, err
 	}
+
+	if args.Nonce == nil {
+		// Hold the addresse's mutex around signing to prevent concurrent assignment of
+		// the same nonce to multiple accounts.
+		s.nonceLock.LockAddr(args.From)
+		defer s.nonceLock.UnlockAddr(args.From)
+	}
+
+	// Set some sanity defaults and terminate on failure
+	if err := args.setDefaults(ctx, s.b); err != nil {
+		return common.Hash{}, err
+	}
 	// Assemble the transaction and sign with the wallet
 	tx := args.toTransaction()
 
@@ -1270,14 +1274,12 @@ type SignTransactionResult struct {
 // The node needs to have the private key of the account corresponding with
 // the given from address and it needs to be unlocked.
 func (s *PublicTransactionPoolAPI) SignTransaction(ctx context.Context, args SendTxArgs) (*SignTransactionResult, error) {
-
 	if args.Nonce == nil {
-		// We'll need to set nonce from pool, and thus we need to lock here
-		nonceMutex.Lock()
-		defer nonceMutex.Unlock()
-
+		// Hold the addresse's mutex around signing to prevent concurrent assignment of
+		// the same nonce to multiple accounts.
+		s.nonceLock.LockAddr(args.From)
+		defer s.nonceLock.UnlockAddr(args.From)
 	}
-
 	if err := args.setDefaults(ctx, s.b); err != nil {
 		return nil, err
 	}