From 6be527dd52f0b40da87a6e2dc372fba5a08dd33a Mon Sep 17 00:00:00 2001 From: Bas van Kervel Date: Thu, 2 Jul 2015 15:26:55 +0200 Subject: [PATCH] prevent discarding requests when parsing fails --- rpc/codec/json.go | 122 ++++++++++++++++++++++------ rpc/codec/json_test.go | 177 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 273 insertions(+), 26 deletions(-) create mode 100644 rpc/codec/json_test.go diff --git a/rpc/codec/json.go b/rpc/codec/json.go index 5d60104f7..b5ef94380 100644 --- a/rpc/codec/json.go +++ b/rpc/codec/json.go @@ -10,64 +10,134 @@ import ( ) const ( - READ_TIMEOUT = 15 // read timeout in seconds + READ_TIMEOUT = 60 // in seconds MAX_REQUEST_SIZE = 1024 * 1024 MAX_RESPONSE_SIZE = 1024 * 1024 ) +var ( + // No new requests in buffer + EmptyRequestQueueError = fmt.Errorf("No incoming requests") + // Next request in buffer isn't yet complete + IncompleteRequestError = fmt.Errorf("Request incomplete") +) + // Json serialization support type JsonCodec struct { - c net.Conn - d *json.Decoder + c net.Conn + reqBuffer []byte + bytesInReqBuffer int + reqLastPos int } // Create new JSON coder instance func NewJsonCoder(conn net.Conn) ApiCoder { return &JsonCodec{ - c: conn, - d: json.NewDecoder(conn), + c: conn, + reqBuffer: make([]byte, MAX_REQUEST_SIZE), + bytesInReqBuffer: 0, + reqLastPos: 0, + } +} + +// Indication if the next request in the buffer is a batch request +func (self *JsonCodec) isNextBatchReq() (bool, error) { + for i := 0; i < self.bytesInReqBuffer; i++ { + switch self.reqBuffer[i] { + case 0x20, 0x09, 0x0a, 0x0d: // allow leading whitespace (JSON whitespace RFC4627) + continue + case 0x7b: // single req + return false, nil + case 0x5b: // batch req + return true, nil + default: + return false, &json.InvalidUnmarshalError{} + } + } + + return false, EmptyRequestQueueError +} + +// remove parsed request from buffer +func (self *JsonCodec) resetReqbuffer(pos int) { + copy(self.reqBuffer, self.reqBuffer[pos:self.bytesInReqBuffer]) + self.reqLastPos = 0 + self.bytesInReqBuffer -= pos +} + +// parse request in buffer +func (self *JsonCodec) nextRequest() (requests []*shared.Request, isBatch bool, err error) { + if isBatch, err := self.isNextBatchReq(); err == nil { + if isBatch { + requests = make([]*shared.Request, 0) + for ; self.reqLastPos <= self.bytesInReqBuffer; self.reqLastPos++ { + if err = json.Unmarshal(self.reqBuffer[:self.reqLastPos], &requests); err == nil { + self.resetReqbuffer(self.reqLastPos) + return requests, true, nil + } + } + return nil, true, IncompleteRequestError + } else { + request := shared.Request{} + for ; self.reqLastPos <= self.bytesInReqBuffer; self.reqLastPos++ { + if err = json.Unmarshal(self.reqBuffer[:self.reqLastPos], &request); err == nil { + requests := make([]*shared.Request, 1) + requests[0] = &request + self.resetReqbuffer(self.reqLastPos) + return requests, false, nil + } + } + return nil, true, IncompleteRequestError + } + } else { + return nil, false, err } } // Serialize obj to JSON and write it to conn func (self *JsonCodec) ReadRequest() (requests []*shared.Request, isBatch bool, err error) { + if self.bytesInReqBuffer != 0 { + req, batch, err := self.nextRequest() + if err == nil { + return req, batch, err + } + if err != IncompleteRequestError { + return nil, false, err + } + } + + // no/incomplete request in buffer -> read more data first deadline := time.Now().Add(READ_TIMEOUT * time.Second) if err := self.c.SetDeadline(deadline); err != nil { return nil, false, err } + var retErr error for { - var err error - singleRequest := shared.Request{} - if err = self.d.Decode(&singleRequest); err == nil { - requests := make([]*shared.Request, 1) - requests[0] = &singleRequest - return requests, false, nil + n, err := self.c.Read(self.reqBuffer[self.bytesInReqBuffer:]) + if err != nil { + retErr = err + break } - fmt.Printf("err %T %v\n", err) + self.bytesInReqBuffer += n - if opErr, ok := err.(*net.OpError); ok { - if opErr.Timeout() { - break - } + requests, isBatch, err := self.nextRequest() + if err == nil { + return requests, isBatch, nil } - requests = make([]*shared.Request, 0) - if err = self.d.Decode(&requests); err == nil { - return requests, true, nil + if err == IncompleteRequestError || err == EmptyRequestQueueError { + continue // need more data } - if opErr, ok := err.(*net.OpError); ok { - if opErr.Timeout() { - break - } - } + retErr = err + break } - self.c.Close() // timeout - return nil, false, fmt.Errorf("Timeout reading request") + self.c.Close() + return nil, false, retErr } func (self *JsonCodec) ReadResponse() (interface{}, error) { diff --git a/rpc/codec/json_test.go b/rpc/codec/json_test.go new file mode 100644 index 000000000..60cac05f7 --- /dev/null +++ b/rpc/codec/json_test.go @@ -0,0 +1,177 @@ +package codec + +import ( + "bytes" + "io" + "net" + "testing" + "time" +) + +type jsonTestConn struct { + buffer *bytes.Buffer +} + +func newJsonTestConn(data []byte) *jsonTestConn { + return &jsonTestConn{ + buffer: bytes.NewBuffer(data), + } +} + +func (self *jsonTestConn) Read(p []byte) (n int, err error) { + return self.buffer.Read(p) +} + +func (self *jsonTestConn) Write(p []byte) (n int, err error) { + return self.buffer.Write(p) +} + +func (self *jsonTestConn) Close() error { + // not implemented + return nil +} + +func (self *jsonTestConn) LocalAddr() net.Addr { + // not implemented + return nil +} + +func (self *jsonTestConn) RemoteAddr() net.Addr { + // not implemented + return nil +} + +func (self *jsonTestConn) SetDeadline(t time.Time) error { + return nil +} + +func (self *jsonTestConn) SetReadDeadline(t time.Time) error { + return nil +} + +func (self *jsonTestConn) SetWriteDeadline(t time.Time) error { + return nil +} + +func TestJsonDecoderWithValidRequest(t *testing.T) { + reqdata := []byte(`{"jsonrpc":"2.0","method":"modules","params":[],"id":64}`) + decoder := newJsonTestConn(reqdata) + + jsonDecoder := NewJsonCoder(decoder) + requests, batch, err := jsonDecoder.ReadRequest() + + if err != nil { + t.Errorf("Read valid request failed - %v", err) + } + + if len(requests) != 1 { + t.Errorf("Expected to get a single request but got %d", len(requests)) + } + + if batch { + t.Errorf("Got batch indication while expecting single request") + } + + if requests[0].Id != float64(64) { + t.Errorf("Expected req.Id == 64 but got %v", requests[0].Id) + } + + if requests[0].Method != "modules" { + t.Errorf("Expected req.Method == 'modules' got '%s'", requests[0].Method) + } +} + +func TestJsonDecoderWithValidBatchRequest(t *testing.T) { + reqdata := []byte(`[{"jsonrpc":"2.0","method":"modules","params":[],"id":64}, + {"jsonrpc":"2.0","method":"modules","params":[],"id":64}]`) + decoder := newJsonTestConn(reqdata) + + jsonDecoder := NewJsonCoder(decoder) + requests, batch, err := jsonDecoder.ReadRequest() + + if err != nil { + t.Errorf("Read valid batch request failed - %v", err) + } + + if len(requests) != 2 { + t.Errorf("Expected to get two requests but got %d", len(requests)) + } + + if !batch { + t.Errorf("Got no batch indication while expecting batch request") + } + + for i := 0; i < len(requests); i++ { + if requests[i].Id != float64(64) { + t.Errorf("Expected req.Id == 64 but got %v", requests[i].Id) + } + + if requests[i].Method != "modules" { + t.Errorf("Expected req.Method == 'modules' got '%s'", requests[i].Method) + } + } +} + +func TestJsonDecoderWithIncompleteMessage(t *testing.T) { + reqdata := []byte(`{"jsonrpc":"2.0","method":"modules","pa`) + decoder := newJsonTestConn(reqdata) + + jsonDecoder := NewJsonCoder(decoder) + requests, batch, err := jsonDecoder.ReadRequest() + + if err != io.EOF { + t.Errorf("Expected to read an incomplete request err but got %v", err) + } + + // remaining message + decoder.Write([]byte(`rams":[],"id":64}`)) + requests, batch, err = jsonDecoder.ReadRequest() + + if err != nil { + t.Errorf("Read valid request failed - %v", err) + } + + if len(requests) != 1 { + t.Errorf("Expected to get a single request but got %d", len(requests)) + } + + if batch { + t.Errorf("Got batch indication while expecting single request") + } + + if requests[0].Id != float64(64) { + t.Errorf("Expected req.Id == 64 but got %v", requests[0].Id) + } + + if requests[0].Method != "modules" { + t.Errorf("Expected req.Method == 'modules' got '%s'", requests[0].Method) + } +} + +func TestJsonDecoderWithInvalidIncompleteMessage(t *testing.T) { + reqdata := []byte(`{"jsonrpc":"2.0","method":"modules","pa`) + decoder := newJsonTestConn(reqdata) + + jsonDecoder := NewJsonCoder(decoder) + requests, batch, err := jsonDecoder.ReadRequest() + + if err != io.EOF { + t.Errorf("Expected to read an incomplete request err but got %v", err) + } + + // remaining message + decoder.Write([]byte(`rams":[],"id:64"}`)) + requests, batch, err = jsonDecoder.ReadRequest() + + if err == nil { + t.Errorf("Expected an error but got nil") + } + + if len(requests) != 0 { + t.Errorf("Expected to get no requests but got %d", len(requests)) + } + + if batch { + t.Errorf("Got batch indication while expecting non batch") + } +}