Anjay is a C library that aims to be the reference implementation of the OMA Lightweight Machine-to-Machine (LwM2M) device management protocol. It eases development of fully-featured LwM2M client applications by taking care of protocol details, allowing the user to focus on device-specific aspects.
The project has been created and is actively maintained by AVSystem.
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LwM2M Bootstrap Interface:
- Request
- Finish
- Write
- Delete
- Discover
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LwM2M Client Registration Interface:
- Register
- Update
- De-register
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LwM2M Device Management and Service Enablement Interface:
- Read
- Discover
- Write
- Write-Attributes
- Execute
- Create
- Delete
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LwM2M Information Reporting Interface:
- Observe
- Notify
- Cancel Observation
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LwM2M Security modes:
- DTLS with Certificates (if supported by backend TLS library)
- DTLS with PSK (if supported by backend TLS library)
- NoSec mode
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Supported TLS backends:
- mbed TLS
- OpenSSL
- tinydtls
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Supported platforms:
- any Unix-like operating system, such as Linux (including Android), mac OS and *BSD
- Microsoft Windows (preliminary support, see README.Windows.md for details)
- any embedded platform (e.g. FreeRTOS, ThreadX) with lwIP networking stack
- porting is possible for any other platform that has ISO C99 compiler available, see Porting guide for non-POSIX platforms for details
- preimplemented integration layer for ARM mbed OS is available commercially
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CoAP data formats:
- TLV
- Opaque
- Plain Text (including base64 encoding of opaque data)
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CoAP BLOCK transfers (for transferring data that does not fit in a single UDP packet):
- Block1 (sending / receiving requests)
- Block2 (sending responses)
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Pre-implemented LwM2M Objects:
- Access Control
- Security
- Server
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Stream-oriented persistence API
OMA LwM2M is a remote device management and telemetry protocol designed to conserve network resources. It is especially suitable for constrained wireless devices, where network communication is a major factor affecting battery life. LwM2M features secure (DTLS-encrypted) methods of remote bootstrapping, configuration and notifications over UDP or SMS.
More details about OMA LwM2M: Brief introduction to LwM2M
- C compiler with C99 support,
- CMake 2.8.11+,
- avs_commons - included in the repository as a subproject,
- If DTLS support is enabled, at least one of:
- Optional dependencies (required for tests):
- C++ compiler with C++11 support,
- Python 3.5+,
- pybind11 - included in the repository as a subproject,
- scan-build - for static analysis.
sudo apt-get install git build-essential cmake libmbedtls-dev zlib1g-dev
# Optionally for tests:
sudo apt-get install libpython3-dev libssl-dev python3 python3-cryptography python3-jinja2 python3-sphinx python3-requests clang valgrind clang-tools# Required for mbedtls-devel and python3.5
sudo yum install -y https://centos7.iuscommunity.org/ius-release.rpm
sudo yum install -y which git make cmake mbedtls-devel gcc gcc-c++
# Optionally for tests:
sudo yum install -y valgrind valgrind-devel openssl openssl-devel python35u python35u-devel python35u-pip python-sphinx python-sphinx_rtd_theme clang-analyzer
# Some test scripts expect Python >=3.5 to be available via `python3` command
# Use update-alternatives to create a /usr/bin/python3 symlink with priority 0
# (lowest possible)
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.5 0
sudo python3 -m pip install cryptography jinja2 requestsmacOS Sierra with Homebrew
brew install cmake mbedtls
# Optionally for tests:
brew install python3 openssl llvm
pip3 install cryptography sphinx sphinx_rtd_theme requestsTo compile Anjay demo client and connect it to a local LwM2M server listening on default 5683 port:
git clone https://github.com/AVSystem/Anjay.git \
&& cd Anjay \
&& git submodule update --init \
&& cmake . \
&& make -j \
&& ./output/bin/demo --server-uri coap://127.0.0.1:5683First, make sure all necessary submodules are downloaded and up-to-date:
git submodule update --initBy default demo client compiles with DTLS enabled and uses mbedtls as a DTLS provider,
but you may choose other DTLS backends currently supported by setting DTLS_BACKEND in
a CMake invocation to one of the following DTLS backends: openssl, mbedtls or tinydtls:
cmake . -DDTLS_BACKEND="mbedtls" && make -jOr, if a lack of security (not recommended) is what you need for some reason:
cmake . -DDTLS_BACKEND="" && make -jCompiled executables, including demo client, can be found in output/bin subdirectory.
For a detailed guide on configuring and compiling the project (including cross-compiling), see Compiling client applications.
To start the demo client:
# uses plain CoAP
./output/bin/demo --server-uri coap://127.0.0.1:5683
# uses DTLS in PSK mode, with PSK identity "foo" and secret key "bar" (hex-encoded)
./output/bin/demo --server-uri coaps://127.0.0.1:5684 --security-mode psk --identity 666f6f --key 626172NOTE: When establishing a DTLS connection, the URI MUST use "coaps://". In NoSec mode (default), the URI MUST use "coap://".
Running tests on Ubuntu 16.04:
./devconfig && make checkRunning tests on CentOS 7:
# NOTE: clang-3.4 static analyzer (default version for CentOS) gives false
# positives. --without-analysis flag disables static analysis.
./devconfig --without-analysis -DPython_ADDITIONAL_VERSIONS=3.5 && make checkRunning tests on macOS Sierra:
# If the scan-build script is located somewhere else, then you need to
# specify a different SCAN_BUILD_BINARY. Below, we are assumming scan-build
# comes from an llvm package, installed via homebrew.
./devconfig -DSCAN_BUILD_BINARY=/usr/local/Cellar/llvm/*/bin/scan-build && make checkSee LICENSE file.
Anjay LwM2M library comes with the option of full commercial support, provided by AVSystem. The commercial version supports the latest LwM2M 1.1 release. If you're interested in LwM2M Server, be sure to check out the Coiote IoT Device Management platform by AVSystem, which also focuses on LwM2M along with its latest 1.1 specification.
Contributions are welcome! See our contributing guide.