This project is a core (and a member) of CommsChampion Ecosystem, which comes to help in developing binary communication protocols, with main focus on embedded systems with limited resources (including bare-metal ones) and choosing C++(11) programming language to do so.
This project has two major parts: COMMS Library and CommsChampion Tools. The library's components can be used to define protocol messages as well as its transport framing information using mostly declarative statements of classes and types definitions. The tools can be used to visualise, analyse, and debug binary communication protocols, which were developed using COMMS Library.
COMMS is the C++(11) headers only, platform independent library, which makes the implementation of a communication protocol to be an easy and relatively quick process. It provides all the necessary types and classes to make the definition of the custom messages, as well as wrapping transport data fields, to be simple declarative statements of type and class definitions. These statements will specify WHAT needs to be implemented. The COMMS library internals handle the HOW part.
The internals of the COMMS library is mostly template classes which use multiple meta-programming techniques. As the result, only the functionality, required by the protocol being developed, gets compiled in, providing the best code size and speed performance possible. The down side is that compilation process may take a significant amount of time and consume a lot of memory.
The COMMS library allows having single implementation of the binary protocol messages, which can be re-compiled and used for any possible application: bare-metal with constrained resources, Linux based embedded systems, even independent GUI analysis tools.
The COMMS library was specifically developed to be used in embedded systems including bare-metal ones. It doesn't use exceptions and/or RTTI. It also minimises usage of dynamic memory allocation and provides an ability to exclude it altogether if required, which may be needed when developing bare-metal embedded systems.
Core ideas and architecture of the COMMS library is described in Guide to Implementing Communication Protocols in C++ free e-book. However, at this stage the library internals are much more advanced and sophisticated, than examples in the e-book, please don't treat the latter as a guide to library's internals.
Full doxygen generated documentation with the full tutorial inside can be read online and/or downloaded as doc_comms_vX.zip archive from release artefacts.
For quick usage examples please refer to EXAMPLES.md.
This project also contains a set of tool applications (in addition to the COMMS Library), which can be used to develop, monitor and debug custom binary communication protocols, that where developed using the COMMS Library. All the applications are plug-in based, i.e. plug-ins are used to define I/O socket, data filters, and the custom protocol itself. The tools use Qt5 framework for GUI interfaces as well as loading and managing plug-ins.
The current list of available applications is below. Please refer to the wiki page for tutorial on how to use them.
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cc_view is the main generic GUI application for visualisation and analysis of the communication protocols.
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cc_dump is a command line utility, that recognises all the received custom binary protocol messages and dumps them all in CSV format to standard output. It can also record the incoming message into the file, which can be opened later for visual analysis using cc_view GUI application. The tool has an ability to receive a file with definition of outgoing messages, created using cc_view GUI application, and send them one by one in parallel to dumping/recording the incoming messages.
The CommsChampion Tools package provides the following plugins that can be used with any application:
- null_socket - NULL socket, that doesn't produce any incoming data and discards any outgoing data.
- echo_socket - Echo socket, all the data being sent is immediately reported as an incoming data.
- serial_socket - Low level socket that sends and receives data over serial (RS-232) I/O link.
- tcp_client_socket - Client TCP/IP socket, that connects to remote server, sends and receives data over TCP/IP network link.
- tcp_server_socket - Server TCP/IP socket, waits for and accepts all connections from TCP/IP clients, sends and receives data to/from them.
- tcp_proxy_socket - Proxy server TCP/IP socket, combines Server and Client side of TCP/IP connection, can be used to monitor traffic of the messages between remote a client and a server.
- udp_socket - Generic (client/server) UDP/IP socket.
- raw_data_protocol - Protocol definition that defines only a single message type with one field of unlimited length data. It can be used to review the raw data being received from I/O socket.
The full tutorial as well as API documentation can be downloaded as doc_commschampion_vX.zip archive from from release artefacts.
Over the years the COMMS Library grew with features and accumulated multiple nuances to be remembered when defining a new protocol. In order to simplify protocol definition work, a separate toolset, called commsdsl (hosted as separate repository), has been developed. It allows much easier and simpler definition of the protocol, using schema files written in XML based domain specific language, called CommsDSL. The toolset will generate a C++11 code that defines the protocol using appropriate COMMS Library classes and functions, as well as generate extra code required to implement a protocol definition plugin for CommsChampion Tools. Many binary protocols may have nuances that are difficult to express in existing schema language. In order to still allow usage of the schema files for the protocol definition, the toolset allows injection of extra custom code to modify or extend the generated one. The generated code itself is also highly compile time customisable. It allows selection of custom data structures for data storage as well as polymorphic interfaces relevant to the application being developed.
As the result, manual implementation of binary communication protocols from scratch using COMMS Library is not recommended and should be avoided. Please use commsdsl2comms code generator from commsdsl project, which also lists multiple available protocols (with usage examples) that can be used as reference.
The COMMS Library is licensed under the classic GPLv3 / Commercial dual licensing scheme. Please refer to LICENSES page for details.
The COMMS Library requires proper C++11 support which is provided by the following compilers:
- GCC: >=4.8
- Clang: >=3.9
- MSVC: >= 2015
Detailed instructions on how to build and install all the components can be found in BUILD.md file.
As was mentioned earlier, the COMMS library is a headers only one, just have /path/to/comms_champion/install/dir/include directory among your include paths and use the following statement in your sources:
#include "comms/comms.h"
Nothing else is required.
Instructions on how to include the COMMS library in other CMake projects can be found in How to Use CommsChampion in CMake Projects wiki page.
On Windows platforms try to run the *.exe binary (cc_view.exe or cc_dump.exe), which resides in ${CMAKE_ISNTALL_PREFIX}/bin directory. If the execution fails due to missing Qt5 dlls, either set your %PATH% variable accordingly or try to execute generated .bat files (cc_view.bat or cc_dump.bat) residing in the same directory. Another option is to build deploy_qt target to deploy Qt5 libraries into installation directory, whill will allow execution of any .exe file without and extra manupulations.
On Linux platforms use the appropriate shell script (cc_view.sh or cc_dump.sh), which also resides in ${CMAKE_ISNTALL_PREFIX}/bin directory.
Please note that available plugins must reside in the ${CMAKE_ISNTALL_PREFIX}/lib/CommsChampion/plugin directory.
The tools support multiple command line options, please use "-h" or "--help" for the full list.
$> ./install/bin/cc_view.sh -h
$> ./install/bin/cc_dump.sh -h
This repository will follow the Successful Git Branching Model.
The master branch will always point to the latest release, the development is performed on develop branch. As the result it is safe to just clone the sources of this repository and use it without any extra manipulations of looking for the latest stable version among the tags and checking it out.
For bug reports, feature requests, or any other question you may open an issue here in github or e-mail me directly to: arobenko@gmail.com. I usually respond within 24 hours.