Added checks to RPC requests and introduced new flags to customise the parameters (#657)

* added a check to reject rpc requests with batch size > the one set using a newly added flag (rpcbatchlimit)

* added a check to reject rpc requests whose result size > the one set using a newly added flag (rpcreturndatalimit)

* updated the config files and docs

builder/files/config.toml

@@ -8,6 +8,8 @@ chain = "mainnet"
 datadir = "/var/lib/bor/data"
 # ancient = ""
 # keystore = "/var/lib/bor/keystore"
+# "rpc.batchlimit" = 100
+# "rpc.returndatalimit" = 100000
 syncmode = "full"
 # gcmode = "full"
 # snapshot = true

docs/cli/example_config.toml

@@ -8,6 +8,8 @@ log-level = "INFO"           # Set log level for the server
 datadir = "var/lib/bor"      # Path of the data directory to store information
 ancient = ""                 # Data directory for ancient chain segments (default = inside chaindata)
 keystore = ""                # Path of the directory where keystores are located
+"rpc.batchlimit" = 100          # Maximum number of messages in a batch (default=100, use 0 for no limits)
+"rpc.returndatalimit" = 100000  # Maximum size (in bytes) a result of an rpc request could have (default=100000, use 0 for no limits)
 syncmode = "full"            # Blockchain sync mode (only "full" sync supported)
 gcmode = "full"              # Blockchain garbage collection mode ("full", "archive")
 snapshot = true              # Enables the snapshot-database mode

docs/cli/server.md

@@ -16,6 +16,10 @@ The ```bor server``` command runs the Bor client.
 
 - ```keystore```: Path of the directory where keystores are located
 
+- ```rpc.batchlimit```: Maximum number of messages in a batch (default=100, use 0 for no limits) (default: 100)
+
+- ```rpc.returndatalimit```: Maximum size (in bytes) a result of an rpc request could have (default=100000, use 0 for no limits) (default: 100000)
+
 - ```config```: File for the config file
 
 - ```syncmode```: Blockchain sync mode (only "full" sync supported) (default: full)

eth/api_backend.go

@@ -317,6 +317,10 @@ func (b *EthAPIBackend) RPCGasCap() uint64 {
 	return b.eth.config.RPCGasCap
 }
 
+func (b *EthAPIBackend) RPCRpcReturnDataLimit() uint64 {
+	return b.eth.config.RPCReturnDataLimit
+}
+
 func (b *EthAPIBackend) RPCEVMTimeout() time.Duration {
 	return b.eth.config.RPCEVMTimeout
 }

eth/ethconfig/config.go

@@ -94,11 +94,12 @@ var Defaults = Config{
 		GasPrice: big.NewInt(params.GWei),
 		Recommit: 125 * time.Second,
 	},
-	TxPool:        core.DefaultTxPoolConfig,
+	TxPool:             core.DefaultTxPoolConfig,
-	RPCGasCap:     50000000,
+	RPCGasCap:          50000000,
-	RPCEVMTimeout: 5 * time.Second,
+	RPCReturnDataLimit: 100000,
-	GPO:           FullNodeGPO,
+	RPCEVMTimeout:      5 * time.Second,
-	RPCTxFeeCap:   5, // 5 matic
+	GPO:                FullNodeGPO,
+	RPCTxFeeCap:        5, // 5 matic
 }
 
 func init() {
@@ -199,6 +200,9 @@ type Config struct {
 	// RPCGasCap is the global gas cap for eth-call variants.
 	RPCGasCap uint64
 
+	// Maximum size (in bytes) a result of an rpc request could have
+	RPCReturnDataLimit uint64
+
 	// RPCEVMTimeout is the global timeout for eth-call.
 	RPCEVMTimeout time.Duration
 

eth/tracers/api_test.go

@@ -126,6 +126,10 @@ func (b *testBackend) RPCGasCap() uint64 {
 	return 25000000
 }
 
+func (b *testBackend) RPCRpcReturnDataLimit() uint64 {
+	return 100000
+}
+
 func (b *testBackend) ChainConfig() *params.ChainConfig {
 	return b.chainConfig
 }

internal/cli/server/config.go

@@ -60,6 +60,12 @@ type Config struct {
 	// KeyStoreDir is the directory to store keystores
 	KeyStoreDir string `hcl:"keystore,optional" toml:"keystore,optional"`
 
+	// Maximum number of messages in a batch (default=100, use 0 for no limits)
+	RPCBatchLimit uint64 `hcl:"rpc.batchlimit,optional" toml:"rpc.batchlimit,optional"`
+
+	// Maximum size (in bytes) a result of an rpc request could have (default=100000, use 0 for no limits)
+	RPCReturnDataLimit uint64 `hcl:"rpc.returndatalimit,optional" toml:"rpc.returndatalimit,optional"`
+
 	// SyncMode selects the sync protocol
 	SyncMode string `hcl:"syncmode,optional" toml:"syncmode,optional"`
 
@@ -435,12 +441,14 @@ type DeveloperConfig struct {
 
 func DefaultConfig() *Config {
 	return &Config{
-		Chain:          "mainnet",
+		Chain:              "mainnet",
-		Identity:       Hostname(),
+		Identity:           Hostname(),
-		RequiredBlocks: map[string]string{},
+		RequiredBlocks:     map[string]string{},
-		LogLevel:       "INFO",
+		LogLevel:           "INFO",
-		DataDir:        DefaultDataDir(),
+		DataDir:            DefaultDataDir(),
-		Ancient:        "",
+		Ancient:            "",
+		RPCBatchLimit:      100,
+		RPCReturnDataLimit: 100000,
 		P2P: &P2PConfig{
 			MaxPeers:     50,
 			MaxPendPeers: 50,
@@ -936,6 +944,8 @@ func (c *Config) buildEth(stack *node.Node, accountManager *accounts.Manager) (*
 	n.BorLogs = c.BorLogs
 	n.DatabaseHandles = dbHandles
 
+	n.RPCReturnDataLimit = c.RPCReturnDataLimit
+
 	if c.Ancient != "" {
 		n.DatabaseFreezer = c.Ancient
 	}
@@ -986,6 +996,7 @@ func (c *Config) buildNode() (*node.Config, error) {
 			WriteTimeout: c.JsonRPC.HttpTimeout.WriteTimeout,
 			IdleTimeout:  c.JsonRPC.HttpTimeout.IdleTimeout,
 		},
+		RPCBatchLimit: c.RPCBatchLimit,
 	}
 
 	// dev mode

internal/cli/server/flags.go

@@ -46,6 +46,18 @@ func (c *Command) Flags() *flagset.Flagset {
 		Usage: "Path of the directory where keystores are located",
 		Value: &c.cliConfig.KeyStoreDir,
 	})
+	f.Uint64Flag(&flagset.Uint64Flag{
+		Name:    "rpc.batchlimit",
+		Usage:   "Maximum number of messages in a batch (default=100, use 0 for no limits)",
+		Value:   &c.cliConfig.RPCBatchLimit,
+		Default: c.cliConfig.RPCBatchLimit,
+	})
+	f.Uint64Flag(&flagset.Uint64Flag{
+		Name:    "rpc.returndatalimit",
+		Usage:   "Maximum size (in bytes) a result of an rpc request could have (default=100000, use 0 for no limits)",
+		Value:   &c.cliConfig.RPCReturnDataLimit,
+		Default: c.cliConfig.RPCReturnDataLimit,
+	})
 	f.StringFlag(&flagset.StringFlag{
 		Name:  "config",
 		Usage: "File for the config file",

internal/ethapi/api.go

@@ -1078,6 +1078,11 @@ func (s *PublicBlockChainAPI) Call(ctx context.Context, args TransactionArgs, bl
 	if err != nil {
 		return nil, err
 	}
+
+	if int(s.b.RPCRpcReturnDataLimit()) > 0 && len(result.ReturnData) > int(s.b.RPCRpcReturnDataLimit()) {
+		return nil, fmt.Errorf("call returned result of length %d exceeding limit %d", len(result.ReturnData), int(s.b.RPCRpcReturnDataLimit()))
+	}
+
 	// If the result contains a revert reason, try to unpack and return it.
 	if len(result.Revert()) > 0 {
 		return nil, newRevertError(result)

internal/ethapi/backend.go

@@ -48,10 +48,11 @@ type Backend interface {
 	ChainDb() ethdb.Database
 	AccountManager() *accounts.Manager
 	ExtRPCEnabled() bool
-	RPCGasCap() uint64            // global gas cap for eth_call over rpc: DoS protection
+	RPCGasCap() uint64             // global gas cap for eth_call over rpc: DoS protection
-	RPCEVMTimeout() time.Duration // global timeout for eth_call over rpc: DoS protection
+	RPCRpcReturnDataLimit() uint64 // Maximum size (in bytes) a result of an rpc request could have
-	RPCTxFeeCap() float64         // global tx fee cap for all transaction related APIs
+	RPCEVMTimeout() time.Duration  // global timeout for eth_call over rpc: DoS protection
-	UnprotectedAllowed() bool     // allows only for EIP155 transactions.
+	RPCTxFeeCap() float64          // global tx fee cap for all transaction related APIs
+	UnprotectedAllowed() bool      // allows only for EIP155 transactions.
 
 	// Blockchain API
 	SetHead(number uint64)

les/api_backend.go

@@ -294,6 +294,10 @@ func (b *LesApiBackend) RPCGasCap() uint64 {
 	return b.eth.config.RPCGasCap
 }
 
+func (b *LesApiBackend) RPCRpcReturnDataLimit() uint64 {
+	return b.eth.config.RPCReturnDataLimit
+}
+
 func (b *LesApiBackend) RPCEVMTimeout() time.Duration {
 	return b.eth.config.RPCEVMTimeout
 }

node/config.go

@@ -204,6 +204,9 @@ type Config struct {
 
 	// JWTSecret is the hex-encoded jwt secret.
 	JWTSecret string `toml:",omitempty"`
+
+	// Maximum number of messages in a batch
+	RPCBatchLimit uint64 `toml:",omitempty"`
 }
 
 // IPCEndpoint resolves an IPC endpoint based on a configured value, taking into

node/node.go

@@ -113,6 +113,9 @@ func New(conf *Config) (*Node, error) {
 		databases:     make(map[*closeTrackingDB]struct{}),
 	}
 
+	// set RPC batch limit
+	node.inprocHandler.SetRPCBatchLimit(conf.RPCBatchLimit)
+
 	// Register built-in APIs.
 	node.rpcAPIs = append(node.rpcAPIs, node.apis()...)
 
@@ -153,10 +156,10 @@ func New(conf *Config) (*Node, error) {
 	}
 
 	// Configure RPC servers.
-	node.http = newHTTPServer(node.log, conf.HTTPTimeouts)
+	node.http = newHTTPServer(node.log, conf.HTTPTimeouts, conf.RPCBatchLimit)
-	node.httpAuth = newHTTPServer(node.log, conf.HTTPTimeouts)
+	node.httpAuth = newHTTPServer(node.log, conf.HTTPTimeouts, conf.RPCBatchLimit)
-	node.ws = newHTTPServer(node.log, rpc.DefaultHTTPTimeouts)
+	node.ws = newHTTPServer(node.log, rpc.DefaultHTTPTimeouts, conf.RPCBatchLimit)
-	node.wsAuth = newHTTPServer(node.log, rpc.DefaultHTTPTimeouts)
+	node.wsAuth = newHTTPServer(node.log, rpc.DefaultHTTPTimeouts, conf.RPCBatchLimit)
 	node.ipc = newIPCServer(node.log, conf.IPCEndpoint())
 
 	return node, nil

node/rpcstack.go

@@ -81,10 +81,12 @@ type httpServer struct {
 	port     int
 
 	handlerNames map[string]string
+
+	RPCBatchLimit uint64
 }
 
-func newHTTPServer(log log.Logger, timeouts rpc.HTTPTimeouts) *httpServer {
+func newHTTPServer(log log.Logger, timeouts rpc.HTTPTimeouts, rpcBatchLimit uint64) *httpServer {
-	h := &httpServer{log: log, timeouts: timeouts, handlerNames: make(map[string]string)}
+	h := &httpServer{log: log, timeouts: timeouts, handlerNames: make(map[string]string), RPCBatchLimit: rpcBatchLimit}
 
 	h.httpHandler.Store((*rpcHandler)(nil))
 	h.wsHandler.Store((*rpcHandler)(nil))
@@ -283,6 +285,7 @@ func (h *httpServer) enableRPC(apis []rpc.API, config httpConfig) error {
 
 	// Create RPC server and handler.
 	srv := rpc.NewServer()
+	srv.SetRPCBatchLimit(h.RPCBatchLimit)
 	if err := RegisterApis(apis, config.Modules, srv, false); err != nil {
 		return err
 	}
@@ -314,6 +317,7 @@ func (h *httpServer) enableWS(apis []rpc.API, config wsConfig) error {
 	}
 	// Create RPC server and handler.
 	srv := rpc.NewServer()
+	srv.SetRPCBatchLimit(h.RPCBatchLimit)
 	if err := RegisterApis(apis, config.Modules, srv, false); err != nil {
 		return err
 	}

node/rpcstack_test.go

@@ -234,7 +234,7 @@ func Test_checkPath(t *testing.T) {
 func createAndStartServer(t *testing.T, conf *httpConfig, ws bool, wsConf *wsConfig) *httpServer {
 	t.Helper()
 
-	srv := newHTTPServer(testlog.Logger(t, log.LvlDebug), rpc.DefaultHTTPTimeouts)
+	srv := newHTTPServer(testlog.Logger(t, log.LvlDebug), rpc.DefaultHTTPTimeouts, 100)
 	assert.NoError(t, srv.enableRPC(nil, *conf))
 	if ws {
 		assert.NoError(t, srv.enableWS(nil, *wsConf))

packaging/templates/mainnet-v1/archive/config.toml

@@ -4,6 +4,8 @@ chain = "mainnet"
 datadir = "/var/lib/bor/data"
 # ancient = ""
 # keystore = ""
+# "rpc.batchlimit" = 100
+# "rpc.returndatalimit" = 100000
 syncmode = "full"
 gcmode = "archive"
 # snapshot = true

packaging/templates/mainnet-v1/sentry/sentry/bor/config.toml

@@ -4,6 +4,8 @@ chain = "mainnet"
 datadir = "/var/lib/bor/data"
 # ancient = ""
 # keystore = ""
+# "rpc.batchlimit" = 100
+# "rpc.returndatalimit" = 100000
 syncmode = "full"
 # gcmode = "full"
 # snapshot = true

packaging/templates/mainnet-v1/sentry/validator/bor/config.toml

@@ -6,6 +6,8 @@ chain = "mainnet"
 datadir = "/var/lib/bor/data"
 # ancient = ""
 # keystore = "$BOR_DIR/keystore"
+# "rpc.batchlimit" = 100
+# "rpc.returndatalimit" = 100000
 syncmode = "full"
 # gcmode = "full"
 # snapshot = true

packaging/templates/mainnet-v1/without-sentry/bor/config.toml

@@ -6,6 +6,8 @@ chain = "mainnet"
 datadir = "/var/lib/bor/data"
 # ancient = ""
 # keystore = "$BOR_DIR/keystore"
+# "rpc.batchlimit" = 100
+# "rpc.returndatalimit" = 100000
 syncmode = "full"
 # gcmode = "full"
 # snapshot = true

packaging/templates/testnet-v4/archive/config.toml

@@ -4,6 +4,8 @@ chain = "mumbai"
 datadir = "/var/lib/bor/data"
 # ancient = ""
 # keystore = ""
+# "rpc.batchlimit" = 100
+# "rpc.returndatalimit" = 100000
 syncmode = "full"
 gcmode = "archive"
 # snapshot = true

packaging/templates/testnet-v4/sentry/sentry/bor/config.toml

@@ -4,6 +4,8 @@ chain = "mumbai"
 datadir = "/var/lib/bor/data"
 # ancient = ""
 # keystore = ""
+# "rpc.batchlimit" = 100
+# "rpc.returndatalimit" = 100000
 syncmode = "full"
 # gcmode = "full"
 # snapshot = true

packaging/templates/testnet-v4/sentry/validator/bor/config.toml

@@ -6,6 +6,8 @@ chain = "mumbai"
 datadir = "/var/lib/bor/data"
 # ancient = ""
 # keystore = "$BOR_DIR/keystore"
+# "rpc.batchlimit" = 100
+# "rpc.returndatalimit" = 100000
 syncmode = "full"
 # gcmode = "full"
 # snapshot = true

packaging/templates/testnet-v4/without-sentry/bor/config.toml

@@ -6,6 +6,8 @@ chain = "mumbai"
 datadir = "/var/lib/bor/data"
 # ancient = ""
 # keystore = "$BOR_DIR/keystore"
+# "rpc.batchlimit" = 100
+# "rpc.returndatalimit" = 100000
 syncmode = "full"
 # gcmode = "full"
 # snapshot = true

rpc/server.go

@@ -18,6 +18,7 @@ package rpc
 
 import (
 	"context"
+	"fmt"
 	"io"
 	"sync/atomic"
 
@@ -47,6 +48,8 @@ type Server struct {
 	idgen    func() ID
 	run      int32
 	codecs   mapset.Set
+
+	BatchLimit uint64
 }
 
 // NewServer creates a new server instance with no registered handlers.
@@ -59,6 +62,10 @@ func NewServer() *Server {
 	return server
 }
 
+func (s *Server) SetRPCBatchLimit(batchLimit uint64) {
+	s.BatchLimit = batchLimit
+}
+
 // RegisterName creates a service for the given receiver type under the given name. When no
 // methods on the given receiver match the criteria to be either a RPC method or a
 // subscription an error is returned. Otherwise a new service is created and added to the
@@ -105,12 +112,23 @@ func (s *Server) serveSingleRequest(ctx context.Context, codec ServerCodec) {
 	reqs, batch, err := codec.readBatch()
 	if err != nil {
 		if err != io.EOF {
-			codec.writeJSON(ctx, errorMessage(&invalidMessageError{"parse error"}))
+			if err1 := codec.writeJSON(ctx, err); err1 != nil {
+				log.Warn("WARNING - error in reading batch", "err", err1)
+				return
+			}
 		}
 		return
 	}
+
 	if batch {
-		h.handleBatch(reqs)
+		if s.BatchLimit > 0 && len(reqs) > int(s.BatchLimit) {
+			if err1 := codec.writeJSON(ctx, errorMessage(fmt.Errorf("batch limit %d exceeded: %d requests given", s.BatchLimit, len(reqs)))); err1 != nil {
+				log.Warn("WARNING - requests given exceeds the batch limit", "err", err1)
+				log.Debug("batch limit %d exceeded: %d requests given", s.BatchLimit, len(reqs))
+			}
+		} else {
+			h.handleBatch(reqs)
+		}
 	} else {
 		h.handleMsg(reqs[0])
 	}