Merge pull request #266 from OffchainLabs/rpc-methods-filter

Add API Filter to node

arbitrum/backend.go

@@ -51,6 +51,14 @@ func NewBackend(stack *node.Node, config *Config, chainDb ethdb.Database, publis
 		chanNewBlock: make(chan struct{}, 1),
 	}
 
+	if len(config.AllowMethod) > 0 {
+		rpcFilter := make(map[string]bool)
+		for _, method := range config.AllowMethod {
+			rpcFilter[method] = true
+		}
+		backend.stack.ApplyAPIFilter(rpcFilter)
+	}
+
 	backend.bloomIndexer.Start(backend.arb.BlockChain())
 	filterSystem, err := createRegisterAPIBackend(backend, filterConfig, config.ClassicRedirect, config.ClassicRedirectTimeout)
 	if err != nil {

arbitrum/config.go

@@ -37,6 +37,8 @@ type Config struct {
 	ClassicRedirect        string        `koanf:"classic-redirect"`
 	ClassicRedirectTimeout time.Duration `koanf:"classic-redirect-timeout"`
 	MaxRecreateStateDepth  int64         `koanf:"max-recreate-state-depth"`
+
+	AllowMethod []string `koanf:"allow-method"`
 }
 
 type ArbDebugConfig struct {
@@ -57,6 +59,7 @@ func ConfigAddOptions(prefix string, f *flag.FlagSet) {
 	f.Int(prefix+".filter-log-cache-size", DefaultConfig.FilterLogCacheSize, "log filter system maximum number of cached blocks")
 	f.Duration(prefix+".filter-timeout", DefaultConfig.FilterTimeout, "log filter system maximum time filters stay active")
 	f.Int64(prefix+".max-recreate-state-depth", DefaultConfig.MaxRecreateStateDepth, "maximum depth for recreating state, measured in l2 gas (0=don't recreate state, -1=infinite, -2=use default value for archive or non-archive node (whichever is configured))")
+	f.StringSlice(prefix+".allow-method", DefaultConfig.AllowMethod, "list of whitelisted rpc methods")
 	arbDebug := DefaultConfig.ArbDebug
 	f.Uint64(prefix+".arbdebug.block-range-bound", arbDebug.BlockRangeBound, "bounds the number of blocks arbdebug calls may return")
 	f.Uint64(prefix+".arbdebug.timeout-queue-bound", arbDebug.TimeoutQueueBound, "bounds the length of timeout queues arbdebug calls may return")
@@ -81,6 +84,7 @@ var DefaultConfig = Config{
 	FeeHistoryMaxBlockCount: 1024,
 	ClassicRedirect:         "",
 	MaxRecreateStateDepth:   UninitializedMaxRecreateStateDepth, // default value should be set for depending on node type (archive / non-archive)
+	AllowMethod:             []string{},
 	ArbDebug: ArbDebugConfig{
 		BlockRangeBound:   256,
 		TimeoutQueueBound: 512,

node/node.go

@@ -69,6 +69,8 @@ type Node struct {
 	inprocHandler *rpc.Server // In-process RPC request handler to process the API requests
 
 	databases map[*closeTrackingDB]struct{} // All open databases
+
+	apiFilter map[string]bool // Whitelisting API methods
 }
 
 const (
@@ -378,6 +380,11 @@ func (n *Node) obtainJWTSecret(cliParam string) ([]byte, error) {
 	return jwtSecret, nil
 }
 
+// ApplyAPIFilter is the first step in whitelisting given rpc methods inside apiFilter
+func (n *Node) ApplyAPIFilter(apiFilter map[string]bool) {
+	n.apiFilter = apiFilter
+}
+
 // startRPC is a helper method to configure all the various RPC endpoints during node
 // startup. It's not meant to be called at any time afterwards as it makes certain
 // assumptions about the state of the node.
@@ -418,6 +425,7 @@ func (n *Node) startRPC() error {
 			Vhosts:             n.config.HTTPVirtualHosts,
 			Modules:            n.config.HTTPModules,
 			prefix:             n.config.HTTPPathPrefix,
+			apiFilter:          n.apiFilter,
 		}); err != nil {
 			return err
 		}
@@ -431,9 +439,10 @@ func (n *Node) startRPC() error {
 			return err
 		}
 		if err := server.enableWS(openAPIs, wsConfig{
-			Modules: n.config.WSModules,
-			Origins: n.config.WSOrigins,
-			prefix:  n.config.WSPathPrefix,
+			Modules:   n.config.WSModules,
+			Origins:   n.config.WSOrigins,
+			prefix:    n.config.WSPathPrefix,
+			apiFilter: n.apiFilter,
 		}); err != nil {
 			return err
 		}
@@ -453,6 +462,7 @@ func (n *Node) startRPC() error {
 			Modules:            n.config.AuthModules,
 			prefix:             DefaultAuthPrefix,
 			jwtSecret:          secret,
+			apiFilter:          n.apiFilter,
 		}); err != nil {
 			return err
 		}
@@ -467,6 +477,7 @@ func (n *Node) startRPC() error {
 			Origins:   n.config.AuthOrigins,
 			prefix:    DefaultAuthPrefix,
 			jwtSecret: secret,
+			apiFilter: n.apiFilter,
 		}); err != nil {
 			return err
 		}

node/rpcstack.go

@@ -42,6 +42,7 @@ type httpConfig struct {
 	Vhosts             []string
 	prefix             string // path prefix on which to mount http handler
 	jwtSecret          []byte // optional JWT secret
+	apiFilter          map[string]bool
 }
 
 // wsConfig is the JSON-RPC/Websocket configuration
@@ -50,6 +51,7 @@ type wsConfig struct {
 	Modules   []string
 	prefix    string // path prefix on which to mount ws handler
 	jwtSecret []byte // optional JWT secret
+	apiFilter map[string]bool
 }
 
 type rpcHandler struct {
@@ -302,6 +304,7 @@ func (h *httpServer) enableRPC(apis []rpc.API, config httpConfig) error {
 
 	// Create RPC server and handler.
 	srv := rpc.NewServer()
+	srv.ApplyAPIFilter(config.apiFilter)
 	if err := RegisterApis(apis, config.Modules, srv); err != nil {
 		return err
 	}
@@ -339,6 +342,7 @@ func (h *httpServer) enableWS(apis []rpc.API, config wsConfig) error {
 	}
 	// Create RPC server and handler.
 	srv := rpc.NewServer()
+	srv.ApplyAPIFilter(config.apiFilter)
 	if err := RegisterApis(apis, config.Modules, srv); err != nil {
 		return err
 	}

rpc/server.go

@@ -65,6 +65,10 @@ func NewServer() *Server {
 	return server
 }
 
+func (s *Server) ApplyAPIFilter(apiFilter map[string]bool) {
+	s.services.apiFilter = apiFilter
+}
+
 // 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

rpc/service.go

@@ -38,6 +38,8 @@ var (
 type serviceRegistry struct {
 	mu       sync.Mutex
 	services map[string]service
+
+	apiFilter map[string]bool
 }
 
 // service represents a registered object.
@@ -81,11 +83,17 @@ func (r *serviceRegistry) registerName(name string, rcvr interface{}) error {
 		}
 		r.services[name] = svc
 	}
-	for name, cb := range callbacks {
+	for methodName, cb := range callbacks {
+		if r.apiFilter != nil {
+			key := name + "_" + methodName
+			if _, ok := r.apiFilter[key]; !ok {
+				continue
+			}
+		}
 		if cb.isSubscribe {
-			svc.subscriptions[name] = cb
+			svc.subscriptions[methodName] = cb
 		} else {
-			svc.callbacks[name] = cb
+			svc.callbacks[methodName] = cb
 		}
 	}
 	return nil