From 0bb19ba8bd00b424de4af419b0c9599ac625c72a Mon Sep 17 00:00:00 2001
From: Jan Dittberner <jandd@cacert.org>
Date: Mon, 20 Apr 2020 22:01:06 +0200
Subject: [PATCH] Introduce configurable buffer size

---
 client/config.go             |  2 ++
 client/main.go               |  8 +++++++-
 client/processing/process.go |  2 +-
 client/protocol/protocol.go  | 16 +++++++++++++---
 4 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/client/config.go b/client/config.go
index 719dded..d8b19da 100644
--- a/client/config.go
+++ b/client/config.go
@@ -11,6 +11,7 @@ import (
 type ClientConfig struct {
 	SerialAddress string `yaml:"serial_address"`
 	BaudRate      int    `yaml:"serial_baudrate"`
+	BufferSize    uint16 `yaml:"serial_buffer_size"`
 	Paranoid      bool   `yaml:"paranoid"`
 	Debug         bool   `yaml:"debug"`
 	GNUPGBinary   string `yaml:"gnupg_bin"`
@@ -21,6 +22,7 @@ type ClientConfig struct {
 var defaultConfig = ClientConfig{
 	SerialAddress: "/dev/ttyUSB0",
 	BaudRate:      115200,
+	BufferSize:    2048,
 	Paranoid:      false,
 	Debug:         false,
 	OpenSSLBinary: "/usr/bin/openssl",
diff --git a/client/main.go b/client/main.go
index bb3c61d..6f7b4ff 100644
--- a/client/main.go
+++ b/client/main.go
@@ -46,7 +46,13 @@ func main() {
 	responseChannel := make(chan *datastructures.SignerResponse, 1)
 
 	readWriteCloser := (io.ReadWriteCloser)(port)
-	protocolHandler := protocol.NewProtocolHandler(requestChannel, &responseChannel, &readWriteCloser)
+	clientProtocolConfig := protocol.NewSignerProtocolConfig()
+	if clientConfig.BufferSize != 0 {
+		clientProtocolConfig.BufferSize = int(clientConfig.BufferSize)
+	}
+	protocolHandler := protocol.NewProtocolHandler(
+		requestChannel, &responseChannel, &readWriteCloser, clientProtocolConfig,
+	)
 
 	cancelChannel := make(chan os.Signal, 1)
 	signal.Notify(cancelChannel, syscall.SIGTERM, syscall.SIGINT)
diff --git a/client/processing/process.go b/client/processing/process.go
index 6263920..ed93b3d 100644
--- a/client/processing/process.go
+++ b/client/processing/process.go
@@ -8,7 +8,7 @@ import (
 
 func Process(response *datastructures.SignerResponse) (err error) {
 	logrus.Infof("process response of type %s", response.Action)
-	logrus.Tracef("process response %v", response)
+	logrus.Tracef("process response %+v", response)
 
 	switch response.Action {
 	case datastructures.ActionNul:
diff --git a/client/protocol/protocol.go b/client/protocol/protocol.go
index 8be88d3..24290e4 100644
--- a/client/protocol/protocol.go
+++ b/client/protocol/protocol.go
@@ -16,6 +16,14 @@ type SignerProtocolHandler interface {
 	HandleSignerProtocol() error
 }
 
+type signerProtocolConfig struct {
+	BufferSize int
+}
+
+func NewSignerProtocolConfig() *signerProtocolConfig {
+	return &signerProtocolConfig{BufferSize: 2048}
+}
+
 type SignerProtocolRequestChannel struct {
 	C      chan *datastructures.SignerRequest
 	closed bool
@@ -45,6 +53,7 @@ type protocolHandler struct {
 	requestChannel   *SignerProtocolRequestChannel
 	responseChannel  *chan *datastructures.SignerResponse
 	serialConnection *io.ReadWriteCloser
+	config           *signerProtocolConfig
 }
 
 type UnExpectedAcknowledgeByte struct {
@@ -67,11 +76,12 @@ func (ph *protocolHandler) Close() error {
 	return nil
 }
 
-func NewProtocolHandler(requests *SignerProtocolRequestChannel, response *chan *datastructures.SignerResponse, serialConnection *io.ReadWriteCloser) SignerProtocolHandler {
+func NewProtocolHandler(requests *SignerProtocolRequestChannel, response *chan *datastructures.SignerResponse, serialConnection *io.ReadWriteCloser, config *signerProtocolConfig) SignerProtocolHandler {
 	return &protocolHandler{
 		requestChannel:   requests,
 		responseChannel:  response,
 		serialConnection: serialConnection,
+		config:           config,
 	}
 }
 
@@ -79,7 +89,7 @@ func (ph *protocolHandler) HandleSignerProtocol() error {
 	for {
 		select {
 		case request := <-ph.requestChannel.C:
-			log.Debugf("handle request %+v", request)
+			log.Tracef("handle request %+v", request)
 			var err error
 			var lengthBytes, responseBytes *[]byte
 			var checksum byte
@@ -187,7 +197,7 @@ func (ph *protocolHandler) readResponse() (*[]byte, *[]byte, byte, error) {
 	var byteBuffer = bytes.NewBuffer(make([]byte, 0))
 
 	for {
-		readBuffer, err := shared.ReceiveBytes(ph.serialConnection, 100, 5*time.Second)
+		readBuffer, err := shared.ReceiveBytes(ph.serialConnection, ph.config.BufferSize, 5*time.Second)
 		if err != nil {
 			return nil, nil, 0, err
 		}