Introduction

FDBus Documentation

FDBus is a middleware development framework targeting the following objectives:

• Inter-Process Communication (IPC) within single host and cross the network
• System abstraction (Windows, Linux, QNX)
• Components based on which middleware is built (job, worker, timer, watch...)

It is something like DBus or SOME/IP, but with its own characteristic:

• Distributed : unlike DBus, it has no central hub
• High performance : endpoints talk to each other directly
• Addressing by name : service is addressable through logic name
• Address allocation : service address is allocated dynamically
• Networking : communication inside host and cross hosts
• IDL and code generation : google protocol buffer is recommended
• Language binding : C++ Java
• Total slution : it is more than an IPC machanism. it is a middleware development framework

Its usage can be found in the following fields:

• Infotainment; instrument cluster, TBox and other ECU with posix-compatible OS running
• Inter VM communication between guest OSes in hypervisor
• SOHO Gateway
• Instrument for distributed industry control

Supported system

• Linux
• Windows
• QNX

Dependence

• cmake - 3.1.3 or above for non-jni build
• cmake - 3.11.1 or above for jni build
• protocol buffer
• compiler supporting C++11 (gcc 4.7+ for Linux; Visual Studio for Windows)

Download

https://github.com/jeremyczhen/fdbus.git

Documentation & Blog

https://blog.csdn.net/jeremy_cz/article/details/89060291

How to build

Build with buildCentral

It is recommended to build with buildCentral.

Prepare buildCentral

1. Install python from Python
2. Install the following modules:

• sudo pip install python-magic
• sudo pip install networkx
• sudo pip install simplejson

3. Download buildCentral:

• git clone https://github.com/jeremyczhen/buildCentral.git

Build with buildCentral

1. Enter buildCentral/workspace to download FDBus and protobuf:

• git clone https://github.com/jeremyczhen/fdbus.git
• git clone https://github.com/jeremyczhen/protobuf.git

2. Supposing we are at root of buildCentral (buildCentral/), build host (Windows, Ubuntu, ...) version of FDBus with the following command. FDBus can be found at: output/stage/host.

• tools/buildCentral/install/mk -thost

3. Cross build for other architectures and FDBus can be found at: output/stage/$variant/$target_arch/:

• tools/buildCentral/install/mk -tarm-qnx - build for ARM QNX
• tools/buildCentral/install/mk -twin-lin - build for Windows Linario

4. You can configure toolchain at: project/build/buildcentralrc

For more details please find help for buildCentral

Build with commands

For Ubuntu host version (running at host machine)

Dependence:

• cmake, gcc are installed

cd ~/workspace
git clone https://github.com/jeremyczhen/fdbus.git #get fdbus source code
cd fdbus;mkdir -p build/install;cd build #create directory for out-of-source build
cmake -DCMAKE_INSTALL_PREFIX=install ../cmake
make install

For cross compiling on Ubuntu (target version)

Dependence:

• cmake and cross-compiling toolchain are installed

cd ~/workspace
git clone https://github.com/jeremyczhen/fdbus.git
cd fdbus;mkdir -p build/install;cd build
#update ../cmake/toolchain.cmake (see below example)
cmake -DCMAKE_INSTALL_PREFIX=install -DCMAKE_TOOLCHAIN_FILE=../cmake/toolchain.cmake ../cmake
make install

For QNX

The same as cross compiling, but the following option should be added to cmake due to minor difference in QNX SDP:

-Dfdbus_SOCKET_ENABLE_PEERCRED=OFF -Dfdbus_PIPE_AS_EVENTFD=true -Dfdbus_LINK_SOCKET_LIB=true

For Windows version

Dependence:

• cmake, msvc are installed

1. cd c:\workspace
2. suppose source code of fdbus is already downloaded and placed at c:\workspace\fdbus
3. create directory c:\workspace\fdbus\build\install and enter c:\workspace\fdbus\build
4. cmake -DCMAKE_INSTALL_PREFIX=install ..\cmake
5. open fdbus.sln in c:\workspace\fdbus\build and build project INSTALL

For cross compiling on Windows (target version)

1. you should have cross-compiling toolchain installed (such as linaro ARM complier)
2. you should have 'make.exe' installed
3. run 'cmake' as [2], adding "-DCMAKE_TOOLCHAIN_FILE=../cmake/toolchain.cmake -G "Unix Makefiles"". Makefiles will be generated.

Build FDBus example (depends on protobuf) for Ubuntu

1. Build protocol buffer

cd ~/workspace
git clone https://github.com/protocolbuffers/protobuf.git #get protobuf source code
cd protobuf;git submodule update --init --recursive
mkdir -p build/install;cd build #create directory for out-of-source build
cmake -DCMAKE_INSTALL_PREFIX=install -DBUILD_SHARED_LIBS=1 ../cmake
make -j4 install #build and install to build/install directory

2. Build fdbus [1]
3. Supposing it is available at ~/workspace/fdbus, build fdbus example

cd ~/workspace/fdbus;mkdir -p build-example/install;cd build-example #create directory for out-of-source build
cmake -DSYSTEM_ROOT=~/workspace/protobuf/build/install;~/workspace/fdbus/build/install -DCMAKE_INSTALL_PREFIX=install ../cmake
PATH=~/workspace/protobuf/build/install/bin:$PATH make install #set PATH to the directory where protoc can be found

Build FDBus example (depends on protobuf) for Windows

Dependence:

• cmake, msvc are installed

1 build protocol buffer

1. cd c:\workspace
2. suppose source code of protocol buffer is already downloaded and placed at c:\workspace\protobuf
3. create directory c:\workspace\protobuf\cbuild\install and enter c:\protobuf\fdbus\cbuild
4. cmake -DCMAKE_INSTALL_PREFIX=install -Dprotobuf_WITH_ZLIB=OFF ..\cmake
5. open protobuf.sln in c:workspaceprotobufcbuild and build project INSTALL

2. Build fdbus [2]
3. Supposing it is available at c:\workspace\fdbus, build example for fdbus

1. create directory c:\workspace\fdbus\build-example\install and enter c:\workspace\fdbus\build-example
2. cmake -DSYSTEM_ROOT=c:\workspace\protobuf\build\install;c:\workspace\fdbus\build\install -DCMAKE_INSTALL_PREFIX=install ..\cmake\pb-example
3. copy c:\workspace\protobuf\cbuild\install\bin\protoc.exe to the directory in PATH environment variable
4. open fdbus.sln in c:\workspace\fdbus\build-example and build project INSTALL

How to run

For single host

1. start name server:

> name_server

2. start clients/servers
3. using lssvc, logsvc, logviewer to look into details

For multi-host

1. start name server at host1:

host1> name_server

2. start host server at host1:

host1> host_server

3. start name server at host2:

host2> name_server -u tcp://ip_of_host1:60000

4. start clients/servers at host1 or host2
5. using lssvc, logsvc, logviewer to look into details

example of toolchain.cmake for cross-compiling

> cat toolchain.cmake
SET(CMAKE_SYSTEM_NAME Linux)
SET(CMAKE_CXX_COMPILER $ENV{QNX_HOST}/usr/bin/q++)
SET(CMAKE_C_COMPILER $ENV{QNX_HOST}/usr/bin/qcc)

cmake options

The following options can be specified with -Dfdbus_XXX=ON/OFF when running cmake.

The status with * is set as default.

fdbus_BUILD_TESTS

*``ON`` : build examples

OFF: don't build examples

fdbus_ENABLE_LOG

*``ON`` : enable log output of fdbus lib

OFF: disable log output of fdbus lib

fdbus_LOG_TO_STDOUT

ON : send fdbus log to stdout (terminal)

*``OFF``: fdbus log is sent to log server

fdbus_ENABLE_MESSAGE_METADATA

*``ON`` : time stamp is included in fdbus message to track delay of message during request-reply interaction

OFF: time stamp is disabled

fdbus_SOCKET_BLOCKING_CONNECT

ON : socket method connect() will be blocked forever if server is not ready to accept

*``OFF``: connect() will be blocked with timer to avoid permanent blocking

fdbus_SOCKET_ENABLE_PEERCRED

*``ON`` : peercred of UDS (Unix Domain Socket) is enabled

OFF: peercred of UDS is disabled

fdbus_ALLOC_PORT_BY_SYSTEM

ON : socket number of servers are allocated by the system

*``OFF``: socket number of servers are allocated by name server

fdbus_SECURITY

ON : enable security

*``OFF``: disable security

fdbus_BUILD_JNI

ON : build JNI shared library and jar package

*``OFF``: don't build JNI artifacts

The following options can be specified with

-DMACRO_DEF='VARIABLE=value;VARIABLE=value'

FDB_CFG_SOCKET_PATH

specify directory of UDS file

default: /tmp

CONFIG_SOCKET_CONNECT_TIMEOUT

specify timeout of connect() when connect to socket server in ms. "0" means block forever.

default: 2000

Security concept

Authentication of client:

1. server registers its name to name server;

2. name server reply with URL and token;

3. server binds to the URL and holds the token;

4. client requests name resolution from name server;

5. name server authenticate client by checking peercred (SO_PEERCRED option of socket), including UID, GID of the client

6. if success, name server gives URL and token of requested server to the client

7. client connects to the server with URL followed by sending the token to the server

8. server verify the token and grant the connection if pass; for unauthorized client, since it does not have a valid token, server will drop the connection

9. name server can assign multiple tokens to server but only send one of them to the client according to security level of the client

Authenication of host

TBD

Known issues

1. Issue: sem_timedwait() is used as notifier and blocker of event loop, leading to timer failure when TOD is changed since sem_wait() take CLOCK_REALTIME clock for timeout control.

Solution: When creating worker thread, pass FDB_WORKER_ENABLE_FD_LOOP as parameter, forcing poll() instead of sem_timedwait() as loop notifier and blocker