protobuf-based rasctl/rascsi command interface (#129)

* Initial protobuf definition

* protobuf result message draft

* Merge with develop branch

* Makefile generates protobuf-based source files

* Interface update

* Fixed typo

* Fixed typo

* Updated returning status

* Serialize return data

* Use correct descriptor

* Made interface fields required

* Deserialize result

* Serialization update

* Updated serialization

* Serialization update

* Updated deserialization

* status handling update

* Evaluate status

* Revert "Evaluate status"

This reverts commit 3d8f2c3252a10618dede5f5fd80c84115551fc7d.

* Completed sense_key enum

* Renaming

* Added protobuf Command

* Updated command evaluation

* Interface update

* Interface update

* Added DeviceType enum

* Improved type-safety

* Fixed typo

* Type-safety update

* Fixed typo

* Error handling update

* Updated list handling

* Error handling update

* Use more C++ strings

* protobuf enums can provide their names

* Fixed listing devices

* Updated logging

* Enum usage cleanup

* More enum cleanup

* Fixed command check

* Updated type check

* Updated enums

* Removed unused variable

* Removed goto, added exception

* Socket handling cleanup

* Code locality cleanup

* Added helper method

* Extracted code

* Updated socket/file handling

* Use C++ I/O

* Use tolower()

* Renaming

* Simplified has_suffix

* Fixed typo

* Use spdlog namespace

* Simplified formatting (endl) of error messages

* Added -s option for changing the runtime log level to rasctl

* Renaming

* Renaming

* Updated error reporting

* Fixed log string formatting

* String conversion cleanup

* Fixed typo

* Log mmap error (happens on 64 bit)

* Improved proto3 compatibility, updated error handling

* CHanges based on review

* Fixed comment

* Comment update

* Updated ListDevice to not directly write to the stream

* Use size_t

* Renaming

* Buffering update

* MapController should not use fp

* Use fd, not fp

* rasctl has to display *all* results

* rasctl has to display *all* results

* Error handling update

* Updated to proto3 protocol

* Optimization by using protobuf-lite

* RaspBian outdated protoc does not support _Name

* Added protobuf-compiler to easyinstall.sh

Co-authored-by: akuker <34318535+akuker@users.noreply.github.com>

easyinstall.sh

@@ -41,7 +41,7 @@ function initialChecks() {
 }
 
 function installPackages() {
-    sudo apt-get update && sudo apt install git libspdlog-dev libpcap-dev genisoimage python3 python3-venv nginx libpcap-dev -y
+    sudo apt-get update && sudo apt install git libspdlog-dev libpcap-dev genisoimage python3 python3-venv nginx libpcap-dev protobuf-compiler -y
 }
 
 # install all dependency packages for RaSCSI Service

src/raspberrypi/Makefile

@@ -73,19 +73,27 @@ BINDIR := ./bin/$(shell echo $(CONNECT_TYPE) | tr '[:upper:]' '[:lower:]')
 # for my specific use case. If you need them - add them back in!
 BIN_ALL = $(BINDIR)/$(RASCSI) $(BINDIR)/$(RASCTL) $(BINDIR)/$(SCSIMON)
 
+SRC_PROTOC = \
+	rasctl_interface.proto
+
+SRC_PROTOBUF = \
+	rasctl_interface.pb.cpp
+
 SRC_RASCSI = \
 	rascsi.cpp \
 	scsi.cpp \
 	gpiobus.cpp \
 	filepath.cpp \
 	fileio.cpp\
-	rascsi_version.cpp
+	rascsi_version.cpp \
+	rasutil.cpp
 #	os.cpp
 #	rasctl_command.cpp
 #	rascsi_mgr.cpp
 #	command_thread.cpp
 SRC_RASCSI += $(shell find ./controllers -name '*.cpp')
 SRC_RASCSI += $(shell find ./devices -name '*.cpp')
+SRC_RASCSI += $(SRC_PROTOBUF)
 
 SRC_SCSIMON = \
 	scsimon.cpp \
@@ -97,8 +105,10 @@ SRC_SCSIMON = \
 
 SRC_RASCTL = \
 	rasctl.cpp\
-	rascsi_version.cpp
+	rascsi_version.cpp \
+	rasutil.cpp
 #	rasctl_command.cpp
+SRC_RASCTL += $(SRC_PROTOBUF)
 
 SRC_RASDUMP = \
 	rasdump.cpp \
@@ -126,9 +136,9 @@ OBJ_RASCSI := $(addprefix $(OBJDIR)/,$(notdir $(SRC_RASCSI:%.cpp=%.o)))
 OBJ_RASCTL := $(addprefix $(OBJDIR)/,$(notdir $(SRC_RASCTL:%.cpp=%.o)))
 OBJ_RASDUMP := $(addprefix $(OBJDIR)/,$(notdir $(SRC_RASDUMP:%.cpp=%.o)))
 OBJ_SASIDUMP := $(addprefix $(OBJDIR)/,$(notdir $(SRC_SASIDUMP:%.cpp=%.o)))
-OBJ_SCSIMON  := $(addprefix $(OBJDIR)/,$(notdir $(SRC_SCSIMON:%.cpp=%.o)))
+OBJ_SCSIMON := $(addprefix $(OBJDIR)/,$(notdir $(SRC_SCSIMON:%.cpp=%.o)))
-#OBJ_ALL := $(OBJ_RASCSI) $(OBJ_RASCTL) $(OBJ_RASDUMP) $(OBJ_SASIDUMP) $(OBJ_SCSIMON)
+
-OBJ_ALL := $(OBJ_RASCSI) $(OBJ_RASCTL) $(OBJ_RASDUMP) $(OBJ_SASIDUMP) $(OBJ_SCSIMON)
+GEN_PROTOBUF := $(SRC_PROTOBUF) rasctl_interface.pb.h
 
 
 # The following will include all of the auto-generated dependency files (*.d)
@@ -143,6 +153,11 @@ $(OBJDIR) $(BINDIR):
 $(OBJDIR)/%.o: %.cpp | $(OBJDIR)
 	$(CXX) $(CXXFLAGS) -c $< -o $@
 
+$(SRC_PROTOBUF): $(SRC_PROTOC)
+	echo "-- Generating protobuf-based source files"
+	protoc --cpp_out=. $(SRC_PROTOC)
+	mv rasctl_interface.pb.cc $@
+
 ## Build Targets:
 ##   all      : Rebuild all of the executable files and re-generate 
 ##              the text versions of the manpages
@@ -155,10 +170,10 @@ ALL: all
 docs: $(DOC_DIR)/rascsi_man_page.txt $(DOC_DIR)/rasctl_man_page.txt $(DOC_DIR)/scsimon_man_page.txt
 
 $(BINDIR)/$(RASCSI): $(OBJ_RASCSI) | $(BINDIR)
-	$(CXX) $(CXXFLAGS) -o $@ $(OBJ_RASCSI) -lpthread -lz -lpcap
+	$(CXX) $(CXXFLAGS) -o $@ $(OBJ_RASCSI) -lpthread -lz -lpcap -lprotobuf-lite
 
 $(BINDIR)/$(RASCTL): $(OBJ_RASCTL) | $(BINDIR)
-	$(CXX) $(CXXFLAGS) -o $@ $(OBJ_RASCTL)
+	$(CXX) $(CXXFLAGS) -o $@ $(OBJ_RASCTL) -lprotobuf-lite
 
 $(BINDIR)/$(RASDUMP): $(OBJ_RASDUMP) | $(BINDIR)
 	$(CXX) $(CXXFLAGS) -o $@ $(OBJ_RASDUMP)
@@ -173,7 +188,7 @@ $(BINDIR)/$(SCSIMON): $(OBJ_SCSIMON) | $(BINDIR)
 ##              compiler files and executable files 
 .PHONY: clean
 clean:
-	rm -rf $(OBJDIR) $(BINDIR)
+	rm -rf $(OBJDIR) $(BINDIR) $(GEN_PROTOBUF)
 
 ##   run      : Launches RaSCSI using some pre-defined drive 
 ##              images. Useful for debugging when you're building 

src/raspberrypi/exceptions.h

@@ -12,20 +12,34 @@
 #if !defined(exceptions_h)
 #define exceptions_h
 
+#include <exception>
+
 class lunexception : public std::exception {
 private:
-        DWORD lun;
+        int lun;
 
 public:
-        lunexception(DWORD lun) {
+        lunexception(int _lun) : lun(_lun) { }
-                this->lun = lun;
-        }
 
         ~lunexception() { }
 
-        DWORD getlun() const {
+        int getlun() const {
             return lun;
         }
 };
 
+class ioexception : public std::exception {
+private:
+	const char *msg;
+
+public:
+	ioexception(const char *_msg) : msg(_msg) { }
+
+	~ioexception() { }
+
+	const char *getmsg() const {
+		return msg;
+	}
+};
+
 #endif

src/raspberrypi/gpiobus.cpp

@@ -179,9 +179,9 @@ BOOL FASTCALL GPIOBUS::Init(mode_e mode)
 	}
 
 	// Map peripheral region memory
-	map = mmap(NULL, 0x1000100,
+	map = mmap(NULL, 0x1000100, PROT_READ | PROT_WRITE, MAP_SHARED, fd, baseaddr);
-		PROT_READ | PROT_WRITE, MAP_SHARED, fd, baseaddr);
 	if (map == MAP_FAILED) {
+        LOGERROR("Error: Unable to map memory");
 		close(fd);
 		return FALSE;
 	}

src/raspberrypi/rasctl.cpp

@@ -11,51 +11,62 @@
 
 #include "os.h"
 #include "rascsi_version.h"
-#include "rasctl.h"
+#include "exceptions.h"
+#include "rasutil.h"
+#include "rasctl_interface.pb.h"
+
+using namespace std;
+using namespace rasctl_interface;
 
 //---------------------------------------------------------------------------
 //
 //	Send Command
 //
 //---------------------------------------------------------------------------
-BOOL SendCommand(char *buf)
+bool SendCommand(const Command& command)
 {
-	int fd;
-	struct sockaddr_in server;
-	FILE *fp;
-
 	// Create a socket to send the command
-	fd = socket(PF_INET, SOCK_STREAM, 0);
+	struct sockaddr_in server;
 	memset(&server, 0, sizeof(server));
 	server.sin_family = PF_INET;
 	server.sin_port   = htons(6868);
-	server.sin_addr.s_addr = htonl(INADDR_LOOPBACK); 
+	server.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+	int fd = socket(PF_INET, SOCK_STREAM, 0);
 
-	// Connect
+	if (connect(fd, (struct sockaddr *)&server, sizeof(struct sockaddr_in)) < 0) {
-	if (connect(fd, (struct sockaddr *)&server,
+		cerr << "Error : Can't connect to rascsi process" << endl;
-		sizeof(struct sockaddr_in)) < 0) {
+		return false;
-		fprintf(stderr, "Error : Can't connect to rascsi process\n");
-		return FALSE;
 	}
 
 	// Send the command
-	fp = fdopen(fd, "r+");
+	FILE *fp = fdopen(fd, "r+");
-	setvbuf(fp, NULL, _IONBF, 0);
+
-	fputs(buf, fp);
+	string data;
+    command.SerializeToString(&data);
+    SerializeProtobufData(fp, data);
 
 	// Receive the message
-	while (1) {
+    bool status = true;
-		if (fgets((char *)buf, BUFSIZ, fp) == NULL) {
+    try {
-			break;
+    	Result result;
-		}
+    	result.ParseFromString(DeserializeProtobufData(fd));
-		printf("%s", buf);
+
-	}
+    	status = result.status();
+
+    	if (!result.msg().empty()) {
+    		cout << result.msg();
+    	}
+    }
+    catch(const ioexception& e) {
+    	cerr << "Error : " << e.getmsg() << endl;
+
+    	// Fall through
+    }
 
-	// Close the socket when we're done
 	fclose(fp);
 	close(fd);
 
-	return TRUE;
+	return status;
 }
 
 //---------------------------------------------------------------------------
@@ -65,48 +76,34 @@ BOOL SendCommand(char *buf)
 //---------------------------------------------------------------------------
 int main(int argc, char* argv[])
 {
-	int opt;
-	int id;
-	int un;
-	int cmd;
-	int type;
-	char *file;
-	BOOL list;
-	int len;
-	char *ext;
-	char buf[BUFSIZ];
-
-	id = -1;
-	un = 0;
-	cmd = -1;
-	type = -1;
-	file = NULL;
-	list = FALSE;
-
 	// Display help
 	if (argc < 2) {
-		fprintf(stderr, "SCSI Target Emulator RaSCSI Controller\n");
+		cerr << "SCSI Target Emulator RaSCSI Controller" << endl;
-		fprintf(stderr, "version %s (%s, %s)\n",
+		cerr << "version " << rascsi_get_version_string() << " (" << __DATE__ << ", " << __TIME__ << ")" << endl;
-			rascsi_get_version_string(),
+		cerr << "Usage: " << argv[0] << " -i ID [-u UNIT] [-c CMD] [-t TYPE] [-f FILE] [-s LOG_LEVEL]" << endl;
-			__DATE__,
+		cerr << " where  ID := {0|1|2|3|4|5|6|7}" << endl;
-			__TIME__);
+		cerr << "        UNIT := {0|1} default setting is 0." << endl;
-		fprintf(stderr,
+		cerr << "        CMD := {attach|detach|insert|eject|protect}" << endl;
-			"Usage: %s -i ID [-u UNIT] [-c CMD] [-t TYPE] [-f FILE]\n",
+		cerr << "        TYPE := {hd|mo|cd|bridge|daynaport}" << endl;
-			argv[0]);
+		cerr << "        FILE := image file path" << endl;
-		fprintf(stderr, " where  ID := {0|1|2|3|4|5|6|7}\n");
+		cerr << "        LOG_LEVEL := log level" << endl;
-		fprintf(stderr, "        UNIT := {0|1} default setting is 0.\n");
+		cerr << " If CMD is 'attach' or 'insert' the FILE parameter is required." << endl;
-		fprintf(stderr, "        CMD := {attach|detach|insert|eject|protect}\n");
+		cerr << "Usage: " << argv[0] << " -l" << endl;
-		fprintf(stderr, "        TYPE := {hd|mo|cd|bridge|daynaport}\n");
+		cerr << "       Print device list." << endl;
-		fprintf(stderr, "        FILE := image file path\n");
+
-		fprintf(stderr, " CMD is 'attach' or 'insert' and FILE parameter is required.\n");
-		fprintf(stderr, "Usage: %s -l\n", argv[0]);
-		fprintf(stderr, "       Print device list.\n");
 		exit(0);
 	}
 
 	// Parse the arguments
+	int opt;
+	int id = -1;
+	int un = 0;
+	Operation cmd = LIST;
+	DeviceType type = UNDEFINED;
+	string params;
 	opterr = 0;
-	while ((opt = getopt(argc, argv, "i:u:c:t:f:l")) != -1) {
+
+	while ((opt = getopt(argc, argv, "i:u:c:t:f:s:l")) != -1) {
 		switch (opt) {
 			case 'i':
 				id = optarg[0] - '0';
@@ -117,158 +114,142 @@ int main(int argc, char* argv[])
 				break;
 
 			case 'c':
-				switch (optarg[0]) {
+				switch (tolower(optarg[0])) {
-					case 'a':				// ATTACH
+					case 'a':
-					case 'A':
+						cmd = ATTACH;
-						cmd = 0;
 						break;
-					case 'd':				// DETACH
+
-					case 'D':
+					case 'd':
-						cmd = 1;
+						cmd = DETACH;
 						break;
-					case 'i':				// INSERT
+
-					case 'I':
+					case 'i':
-						cmd = 2;
+						cmd = INSERT;
 						break;
-					case 'e':				// EJECT
+
-					case 'E':
+					case 'e':
-						cmd = 3;
+						cmd = EJECT;
 						break;
-					case 'p':				// PROTECT
+
-					case 'P':
+					case 'p':
-						cmd = 4;
+						cmd = PROTECT;
 						break;
 				}
 				break;
 
 			case 't':
-				switch (optarg[0]) {
+				switch (tolower(optarg[0])) {
-					case 's':				// HD(SASI)
+					case 's':
-					case 'S':
+						type = SASI_HD;
-					case 'h':				// HD(SCSI)
-					case 'H':
-						// rascsi will figure out if this should be SASI or
-						// SCSI later in the process....
-						type = rasctl_dev_sasi_hd;
 						break;
-					case 'm':				// MO
+
-					case 'M':
+					case 'h':
-						type = rasctl_dev_mo;
+						type = SCSI_HD;
 						break;
-					case 'c':				// CD
+
-					case 'C':
+					case 'm':
-						type = rasctl_dev_cd;
+						type = MO;
 						break;
-					case 'b':				// BRIDGE
+
-					case 'B':
+					case 'c':
-						type = rasctl_dev_br;
+						type = CD;
 						break;
-					// case 'n':				// Nuvolink
+
-					// case 'N':
+					case 'b':
-					// 	type = rasctl_dev_nuvolink;
+						type = BR;
+						break;
+
+					// case 'n':
+					// 	type = NUVOLINK;
 					// 	break;
-					case 'd':				// DaynaPort
+
-					case 'D':
+					case 'd':
-						type = rasctl_dev_daynaport;
+						type = DAYNAPORT;
 						break;
 				}
 				break;
 
 			case 'f':
-				file = optarg;
+				params = optarg;
 				break;
 
 			case 'l':
-				list = TRUE;
+				cmd = LIST;
+				break;
+
+			case 's':
+				cmd = LOG_LEVEL;
+				params = optarg;
 				break;
 		}
 	}
 
+	Command command;
+
+	if (cmd == LOG_LEVEL) {
+		command.set_cmd(LOG_LEVEL);
+		command.set_params(params);
+		SendCommand(command);
+		exit(0);
+	}
+
 	// List display only
-	if (id < 0 && cmd < 0 && type < 0 && file == NULL && list) {
+	if (cmd == LIST || (id < 0 && type == UNDEFINED && params.empty())) {
-		sprintf(buf, "list\n");
+		command.set_cmd(LIST);
-		SendCommand(buf);
+		SendCommand(command);
 		exit(0);
 	}
 
 	// Check the ID number
 	if (id < 0 || id > 7) {
-		fprintf(stderr, "%s Error : Invalid ID %d \n", __PRETTY_FUNCTION__, id);
+		cerr << __PRETTY_FUNCTION__ << " Error : Invalid ID " << id << endl;
 		exit(EINVAL);
 	}
 
 	// Check the unit number
 	if (un < 0 || un > 1) {
-		fprintf(stderr, "%s Error : Invalid UNIT %d \n", __PRETTY_FUNCTION__, un);
+		cerr << __PRETTY_FUNCTION__ << " Error : Invalid UNIT " << un << endl;
 		exit(EINVAL);
 	}
 
-	// Command check
-	if (cmd < 0) {
-		cmd = 0;	// Default command is ATTATCH
-	}
-
 	// Type Check
-	if (cmd == 0 && type < 0) {
+	if (cmd == ATTACH && type == UNDEFINED) {
-
 		// Try to determine the file type from the extension
-		len = file ? strlen(file) : 0;
+		int len = params.length();
-		if (len > 4 && file[len - 4] == '.') {
+		if (len > 4 && params[len - 4] == '.') {
-			ext = &file[len - 3];
+			string ext = params.substr(len - 3);
-			if (xstrcasecmp(ext, "hdf") == 0 ||
+			if (ext == "hdf" || ext == "hds" || ext == "hdn" || ext == "hdi" || ext == "nhd" || ext == "hda") {
-				xstrcasecmp(ext, "hds") == 0 ||
+				type = SASI_HD;
-				xstrcasecmp(ext, "hdn") == 0 ||
+			} else if (ext == "mos") {
-				xstrcasecmp(ext, "hdi") == 0 ||
+				type = MO;
-				xstrcasecmp(ext, "nhd") == 0 ||
+			} else if (ext == "iso") {
-				xstrcasecmp(ext, "hda") == 0) {
+				type = CD;
-				// HD(SASI/SCSI)
-				type = 0;
-			} else if (xstrcasecmp(ext, "mos") == 0) {
-				// MO
-				type = 2;
-			} else if (xstrcasecmp(ext, "iso") == 0) {
-				// CD
-				type = 3;
 			}
 		}
-
-		if (type < 0) {
-			fprintf(stderr, "Error : Invalid type\n");
-			exit(EINVAL);
-		}
 	}
 
-	// File check (command is ATTACH and type is HD)
+	// File check (command is ATTACH and type is HD, for CD and MO the medium (=file) may be inserted later)
-	if (cmd == 0 && type >= 0 && type <= 1) {
+	if (cmd == ATTACH && (type == SASI_HD || type == SCSI_HD) && params.empty()) {
-		if (!file) {
+		cerr << "Error : Invalid file path" << endl;
-			fprintf(stderr, "Error : Invalid file path\n");
+		exit(EINVAL);
-			exit(EINVAL);
-		}
 	}
 
 	// File check (command is INSERT)
-	if (cmd == 2) {
+	if (cmd == INSERT && params.empty()) {
-		if (!file) {
+		cerr << "Error : Invalid file path" << endl;
-			fprintf(stderr, "Error : Invalid file path\n");
+		exit(EINVAL);
-			exit(EINVAL);
-		}
-	}
-
-	// Set unnecessary type to 0
-	if (type < 0) {
-		type = 0;
 	}
 
 	// Generate the command and send it
-	sprintf(buf, "%d %d %d %d %s\n", id, un, cmd, type, file ? file : "-");
+	command.set_id(id);
-	if (!SendCommand(buf)) {
+	command.set_un(un);
-		exit(ENOTCONN);
+	command.set_cmd(cmd);
+	command.set_type(type);
+	if (!params.empty()) {
+		command.set_params(params);
 	}
-
+	if (!SendCommand(command)) {
-	// Display the list
+		exit(ENOTCONN);
-	if (list) {
-		sprintf(buf, "list\n");
-		SendCommand(buf);
 	}
 
 	// All done!

src/raspberrypi/rasctl.h

@@ -1,24 +0,0 @@
-//---------------------------------------------------------------------------
-//
-//	SCSI Target Emulator RaSCSI (*^..^*)
-//	for Raspberry Pi
-//
-//	Powered by XM6 TypeG Technology.
-//	Copyright (C) 2016-2020 GIMONS
-//	Copyright (C) akuker
-//
-//	[ Send Control Command ]
-//
-//---------------------------------------------------------------------------
-
-
-enum rasctl_dev_type : int {
-	rasctl_dev_invalid      = -1,
-	rasctl_dev_sasi_hd      =  0,
-	rasctl_dev_scsi_hd      =  1,
-	rasctl_dev_mo           =  2,
-	rasctl_dev_cd           =  3,
-	rasctl_dev_br           =  4,
-	rasctl_dev_nuvolink     =  5,
-	rasctl_dev_daynaport    =  6,	
-};

src/raspberrypi/rasctl_interface.proto

@@ -0,0 +1,39 @@
+syntax = "proto3";
+
+option optimize_for = LITE_RUNTIME;
+
+package rasctl_interface;
+
+enum Operation {
+    LIST = 0;
+    ATTACH = 1;
+    DETACH = 2;
+    INSERT = 3;
+    EJECT = 4;
+    PROTECT = 5;
+    LOG_LEVEL = 6;
+}
+
+enum DeviceType {
+    UNDEFINED = 0;
+    SASI_HD = 1;
+    SCSI_HD = 2;
+    MO = 3;
+    CD = 4;
+    BR = 5;
+    NUVOLINK = 6;
+    DAYNAPORT = 7;
+}
+
+message Command {
+    Operation cmd = 1;
+    int32 id = 2;
+    int32 un = 3;
+    DeviceType type = 4;
+    string params = 5;
+}
+
+message Result {
+    bool status = 1;
+    string msg = 2;
+}

src/raspberrypi/rasutil.cpp

@@ -0,0 +1,65 @@
+//---------------------------------------------------------------------------
+//
+//	SCSI Target Emulator RaSCSI (*^..^*)
+//	for Raspberry Pi
+//
+//	Powered by XM6 TypeG Technology.
+//	Copyright (C) 2016-2020 GIMONS
+//  Copyright (C) 2020 akuker
+//
+//---------------------------------------------------------------------------
+
+#include <cstring>
+#include <cstdlib>
+#include <unistd.h>
+#include "exceptions.h"
+#include "rasutil.h"
+
+using namespace std;
+
+//---------------------------------------------------------------------------
+//
+//	Serialize/Deserialize protobuf data: Length followed by the actual data
+//
+//---------------------------------------------------------------------------
+
+void SerializeProtobufData(FILE *fp, const string& data)
+{
+	// Write the size of the protobuf data as a header
+    size_t size = data.length();
+    fwrite(&size, sizeof(size), 1, fp);
+
+    // Write the actual protobuf data
+    void *buf = malloc(size);
+    memcpy(buf, data.data(), size);
+    fwrite(buf, size, 1, fp);
+    fflush(fp);
+
+    free(buf);
+}
+
+string DeserializeProtobufData(int fd)
+{
+	// First read the header with the size of the protobuf data
+	size_t size;
+	size_t res = read(fd, &size, sizeof(int));
+	if (res != sizeof(int)) {
+		// No more data
+		return "";
+	}
+
+	// Read the actual protobuf data
+	void *buf = malloc(size);
+	res = read(fd, buf, size);
+	if (res != size) {
+		free(buf);
+
+		throw ioexception("Missing protobuf data");
+	}
+
+	// Read protobuf data into a string, to be converted into a protobuf data structure by the caller
+	string data((const char *)buf, size);
+	free(buf);
+
+	return data;
+}

src/raspberrypi/rasutil.h

@@ -0,0 +1,21 @@
+//---------------------------------------------------------------------------
+//
+//	SCSI Target Emulator RaSCSI (*^..^*)
+//	for Raspberry Pi
+//
+//	Powered by XM6 TypeG Technology.
+//	Copyright (C) 2016-2020 GIMONS
+//  Copyright (C) 2020 akuker
+//
+//---------------------------------------------------------------------------
+
+#if !defined(rasutil_h)
+#define rasutil_h
+
+#include <cstdio>
+#include <string>
+
+void SerializeProtobufData(FILE *fp, const std::string& data);
+std::string DeserializeProtobufData(int fd);
+
+#endif

src/raspberrypi/scsi.h

@@ -23,7 +23,20 @@ class ERROR_CODES
 public:
 	enum sense_key : int {
 		NO_SENSE = 0x00,
-		ILLEGAL_REQUEST = 0x05
+		RECOVERED_ERROR = 0x01,
+		NOT_READY = 0x02,
+		MEDIUM_ERROR = 0x03,
+		HARDWARE_ERROR = 0x04,
+		ILLEGAL_REQUEST = 0x05,
+		UNIT_ATTENTION = 0x06,
+		DATA_PROTECT = 0x07,
+		BLANK_CHECK = 0x08,
+		VENDOR_SPECIFIC = 0x09,
+		COPY_ABORTED = 0x0a,
+		ABORTED_COMMAND = 0x0b,
+		VOLUME_OVERFLOW = 0x0d,
+		MISCOMPARE = 0x0e,
+		COMPLETED = 0x0f
 	};
 
 	enum asc : int {