rpc: various fixes/enhancements

rpc: be less restrictive on the request id
rpc: improved documentation
console: upgrade web3.js to version 0.16.0
rpc: cache http connections
rpc: rename wsDomains parameter to wsOrigins

1 files changed, 85 insertions, 80 deletions

diff --git a/rpc/json.go b/rpc/json.go
index a0bfcac04..8a3bea2ee 100644
--- a/rpc/json.go
+++ b/rpc/json.go
@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"io"
 	"reflect"
+	"strconv"
 	"strings"
 	"sync"
 
@@ -40,14 +41,14 @@ const (
 type JSONRequest struct {
 	Method  string          `json:"method"`
 	Version string          `json:"jsonrpc"`
-	Id      *int64          `json:"id,omitempty"`
+	Id      json.RawMessage `json:"id,omitempty"`
 	Payload json.RawMessage `json:"params,omitempty"`
 }
 
 // JSON-RPC response
 type JSONSuccessResponse struct {
 	Version string      `json:"jsonrpc"`
-	Id      int64       `json:"id"`
+	Id      interface{} `json:"id,omitempty"`
 	Result  interface{} `json:"result"`
 }
 
@@ -60,9 +61,9 @@ type JSONError struct {
 
 // JSON-RPC error response
 type JSONErrResponse struct {
-	Version string    `json:"jsonrpc"`
-	Id      *int64    `json:"id,omitempty"`
-	Error   JSONError `json:"error"`
+	Version string      `json:"jsonrpc"`
+	Id      interface{} `json:"id,omitempty"`
+	Error   JSONError   `json:"error"`
 }
 
 // JSON-RPC notification payload
@@ -78,16 +79,16 @@ type jsonNotification struct {
 	Params  jsonSubscription `json:"params"`
 }
 
-// jsonCodec reads and writes JSON-RPC messages to the underlying connection. It also has support for parsing arguments
-// and serializing (result) objects.
+// jsonCodec reads and writes JSON-RPC messages to the underlying connection. It
+// also has support for parsing arguments and serializing (result) objects.
 type jsonCodec struct {
-	closed    chan interface{}
-	closer    sync.Once
-	d         *json.Decoder
-	muEncoder sync.Mutex
-	e         *json.Encoder
-	req       JSONRequest
-	rw        io.ReadWriteCloser
+	closer sync.Once          // close closed channel once
+	closed chan interface{}   // closed on Close
+	decMu  sync.Mutex         // guards d
+	d      *json.Decoder      // decodes incoming requests
+	encMu  sync.Mutex         // guards e
+	e      *json.Encoder      // encodes responses
+	rw     io.ReadWriteCloser // connection
 }
 
 // NewJSONCodec creates a new RPC server codec with support for JSON-RPC 2.0
@@ -109,9 +110,13 @@ func isBatch(msg json.RawMessage) bool {
 	return false
 }
 
-// ReadRequestHeaders will read new requests without parsing the arguments. It will return a collection of requests, an
-// indication if these requests are in batch form or an error when the incoming message could not be read/parsed.
+// ReadRequestHeaders will read new requests without parsing the arguments. It will
+// return a collection of requests, an indication if these requests are in batch
+// form or an error when the incoming message could not be read/parsed.
 func (c *jsonCodec) ReadRequestHeaders() ([]rpcRequest, bool, RPCError) {
+	c.decMu.Lock()
+	defer c.decMu.Unlock()
+
 	var incomingMsg json.RawMessage
 	if err := c.d.Decode(&incomingMsg); err != nil {
 		return nil, false, &invalidRequestError{err.Error()}
@@ -124,21 +129,38 @@ func (c *jsonCodec) ReadRequestHeaders() ([]rpcRequest, bool, RPCError) {
 	return parseRequest(incomingMsg)
 }
 
-// parseRequest will parse a single request from the given RawMessage. It will return the parsed request, an indication
-// if the request was a batch or an error when the request could not be parsed.
+// checkReqId returns an error when the given reqId isn't valid for RPC method calls.
+// valid id's are strings, numbers or null
+func checkReqId(reqId json.RawMessage) error {
+	if len(reqId) == 0 {
+		return fmt.Errorf("missing request id")
+	}
+	if _, err := strconv.ParseFloat(string(reqId), 64); err == nil {
+		return nil
+	}
+	var str string
+	if err := json.Unmarshal(reqId, &str); err == nil {
+		return nil
+	}
+	return fmt.Errorf("invalid request id")
+}
+
+// parseRequest will parse a single request from the given RawMessage. It will return
+// the parsed request, an indication if the request was a batch or an error when
+// the request could not be parsed.
 func parseRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, RPCError) {
 	var in JSONRequest
 	if err := json.Unmarshal(incomingMsg, &in); err != nil {
 		return nil, false, &invalidMessageError{err.Error()}
 	}
 
-	if in.Id == nil {
-		return nil, false, &invalidMessageError{"Server cannot handle notifications"}
+	if err := checkReqId(in.Id); err != nil {
+		return nil, false, &invalidMessageError{err.Error()}
 	}
 
-	// subscribe are special, they will always use `subscribeMethod` as service method
+	// subscribe are special, they will always use `subscribeMethod` as first param in the payload
 	if in.Method == subscribeMethod {
-		reqs := []rpcRequest{rpcRequest{id: *in.Id, isPubSub: true}}
+		reqs := []rpcRequest{rpcRequest{id: &in.Id, isPubSub: true}}
 		if len(in.Payload) > 0 {
 			// first param must be subscription name
 			var subscribeMethod [1]string
@@ -156,7 +178,7 @@ func parseRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, RPCError) {
 	}
 
 	if in.Method == unsubscribeMethod {
-		return []rpcRequest{rpcRequest{id: *in.Id, isPubSub: true,
+		return []rpcRequest{rpcRequest{id: &in.Id, isPubSub: true,
 			method: unsubscribeMethod, params: in.Payload}}, false, nil
 	}
 
@@ -167,10 +189,10 @@ func parseRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, RPCError) {
 	}
 
 	if len(in.Payload) == 0 {
-		return []rpcRequest{rpcRequest{service: elems[0], method: elems[1], id: *in.Id}}, false, nil
+		return []rpcRequest{rpcRequest{service: elems[0], method: elems[1], id: &in.Id}}, false, nil
 	}
 
-	return []rpcRequest{rpcRequest{service: elems[0], method: elems[1], id: *in.Id, params: in.Payload}}, false, nil
+	return []rpcRequest{rpcRequest{service: elems[0], method: elems[1], id: &in.Id, params: in.Payload}}, false, nil
 }
 
 // parseBatchRequest will parse a batch request into a collection of requests from the given RawMessage, an indication
@@ -183,14 +205,17 @@ func parseBatchRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, RPCErro
 
 	requests := make([]rpcRequest, len(in))
 	for i, r := range in {
-		if r.Id == nil {
-			return nil, true, &invalidMessageError{"Server cannot handle notifications"}
+		if err := checkReqId(r.Id); err != nil {
+			return nil, false, &invalidMessageError{err.Error()}
 		}
 
-		// (un)subscribe are special, they will always use the same service.method
+		id := &in[i].Id
+
+		// subscribe are special, they will always use `subscribeMethod` as first param in the payload
 		if r.Method == subscribeMethod {
-			requests[i] = rpcRequest{id: *r.Id, isPubSub: true}
+			requests[i] = rpcRequest{id: id, isPubSub: true}
 			if len(r.Payload) > 0 {
+				// first param must be subscription name
 				var subscribeMethod [1]string
 				if err := json.Unmarshal(r.Payload, &subscribeMethod); err != nil {
 					glog.V(logger.Debug).Infof("Unable to parse subscription method: %v\n", err)
@@ -207,7 +232,7 @@ func parseBatchRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, RPCErro
 		}
 
 		if r.Method == unsubscribeMethod {
-			requests[i] = rpcRequest{id: *r.Id, isPubSub: true, method: unsubscribeMethod, params: r.Payload}
+			requests[i] = rpcRequest{id: id, isPubSub: true, method: unsubscribeMethod, params: r.Payload}
 			continue
 		}
 
@@ -217,9 +242,9 @@ func parseBatchRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, RPCErro
 		}
 
 		if len(r.Payload) == 0 {
-			requests[i] = rpcRequest{service: elems[0], method: elems[1], id: *r.Id, params: nil}
+			requests[i] = rpcRequest{service: elems[0], method: elems[1], id: id, params: nil}
 		} else {
-			requests[i] = rpcRequest{service: elems[0], method: elems[1], id: *r.Id, params: r.Payload}
+			requests[i] = rpcRequest{service: elems[0], method: elems[1], id: id, params: r.Payload}
 		}
 	}
 
@@ -236,58 +261,38 @@ func (c *jsonCodec) ParseRequestArguments(argTypes []reflect.Type, params interf
 	}
 }
 
-func countArguments(args json.RawMessage) (int, error) {
-	var cnt []interface{}
-	if err := json.Unmarshal(args, &cnt); err != nil {
-		return -1, nil
+// parsePositionalArguments tries to parse the given args to an array of values with the given types.
+// It returns the parsed values or an error when the args could not be parsed. Missing optional arguments
+// are returned as reflect.Zero values.
+func parsePositionalArguments(args json.RawMessage, callbackArgs []reflect.Type) ([]reflect.Value, RPCError) {
+	params := make([]interface{}, 0, len(callbackArgs))
+	for _, t := range callbackArgs {
+		params = append(params, reflect.New(t).Interface())
 	}
-	return len(cnt), nil
-}
-
-// parsePositionalArguments tries to parse the given args to an array of values with the given types. It returns the
-// parsed values or an error when the args could not be parsed.
-func parsePositionalArguments(args json.RawMessage, argTypes []reflect.Type) ([]reflect.Value, RPCError) {
-	argValues := make([]reflect.Value, len(argTypes))
-	params := make([]interface{}, len(argTypes))
 
-	n, err := countArguments(args)
-	if err != nil {
+	if err := json.Unmarshal(args, &params); err != nil {
 		return nil, &invalidParamsError{err.Error()}
 	}
-	if n != len(argTypes) {
-		return nil, &invalidParamsError{fmt.Sprintf("insufficient params, want %d have %d", len(argTypes), n)}
-	}
-
-	for i, t := range argTypes {
-		if t.Kind() == reflect.Ptr {
-			// values must be pointers for the Unmarshal method, reflect.
-			// Dereference otherwise reflect.New would create **SomeType
-			argValues[i] = reflect.New(t.Elem())
-			params[i] = argValues[i].Interface()
-
-			// when not specified blockNumbers are by default latest (-1)
-			if blockNumber, ok := params[i].(*BlockNumber); ok {
-				*blockNumber = BlockNumber(-1)
-			}
-		} else {
-			argValues[i] = reflect.New(t)
-			params[i] = argValues[i].Interface()
 
-			// when not specified blockNumbers are by default latest (-1)
-			if blockNumber, ok := params[i].(*BlockNumber); ok {
-				*blockNumber = BlockNumber(-1)
-			}
-		}
+	if len(params) > len(callbackArgs) {
+		return nil, &invalidParamsError{fmt.Sprintf("too many params, want %d got %d", len(callbackArgs), len(params))}
 	}
 
-	if err := json.Unmarshal(args, &params); err != nil {
-		return nil, &invalidParamsError{err.Error()}
+	// assume missing params are null values
+	for i := len(params); i < len(callbackArgs); i++ {
+		params = append(params, nil)
 	}
 
-	// Convert pointers back to values where necessary
-	for i, a := range argValues {
-		if a.Kind() != argTypes[i].Kind() {
-			argValues[i] = reflect.Indirect(argValues[i])
+	argValues := make([]reflect.Value, len(params))
+	for i, p := range params {
+		// verify that JSON null values are only supplied for optional arguments (ptr types)
+		if p == nil && callbackArgs[i].Kind() != reflect.Ptr {
+			return nil, &invalidParamsError{fmt.Sprintf("invalid or missing value for params[%d]", i)}
+		}
+		if p == nil {
+			argValues[i] = reflect.Zero(callbackArgs[i])
+		} else { // deref pointers values creates previously with reflect.New
+			argValues[i] = reflect.ValueOf(p).Elem()
 		}
 	}
 
@@ -295,7 +300,7 @@ func parsePositionalArguments(args json.RawMessage, argTypes []reflect.Type) ([]
 }
 
 // CreateResponse will create a JSON-RPC success response with the given id and reply as result.
-func (c *jsonCodec) CreateResponse(id int64, reply interface{}) interface{} {
+func (c *jsonCodec) CreateResponse(id interface{}, reply interface{}) interface{} {
 	if isHexNum(reflect.TypeOf(reply)) {
 		return &JSONSuccessResponse{Version: jsonRPCVersion, Id: id, Result: fmt.Sprintf(`%#x`, reply)}
 	}
@@ -303,13 +308,13 @@ func (c *jsonCodec) CreateResponse(id int64, reply interface{}) interface{} {
 }
 
 // CreateErrorResponse will create a JSON-RPC error response with the given id and error.
-func (c *jsonCodec) CreateErrorResponse(id *int64, err RPCError) interface{} {
+func (c *jsonCodec) CreateErrorResponse(id interface{}, err RPCError) interface{} {
 	return &JSONErrResponse{Version: jsonRPCVersion, Id: id, Error: JSONError{Code: err.Code(), Message: err.Error()}}
 }
 
 // CreateErrorResponseWithInfo will create a JSON-RPC error response with the given id and error.
 // info is optional and contains additional information about the error. When an empty string is passed it is ignored.
-func (c *jsonCodec) CreateErrorResponseWithInfo(id *int64, err RPCError, info interface{}) interface{} {
+func (c *jsonCodec) CreateErrorResponseWithInfo(id interface{}, err RPCError, info interface{}) interface{} {
 	return &JSONErrResponse{Version: jsonRPCVersion, Id: id,
 		Error: JSONError{Code: err.Code(), Message: err.Error(), Data: info}}
 }
@@ -327,8 +332,8 @@ func (c *jsonCodec) CreateNotification(subid string, event interface{}) interfac
 
 // Write message to client
 func (c *jsonCodec) Write(res interface{}) error {
-	c.muEncoder.Lock()
-	defer c.muEncoder.Unlock()
+	c.encMu.Lock()
+	defer c.encMu.Unlock()
 
 	return c.e.Encode(res)
 }