Wakaama

Wakaama (formerly liblwm2m) is an implementation of the Open Mobile Alliance's LightWeight M2M protocol (LWM2M).

Developers mailing list: https://dev.eclipse.org/mailman/listinfo/wakaama-dev

Security warning

The only official release of Wakaama, version 1.0, is affected by various security issues (CVE-2019-9004, CVE-2021-41040).

Please use the most recent commit in the main branch. Release 1.0 is not supported anymore.

License

This work is dual-licensed under the Eclipse Public License v2.0 and Eclipse Distribution License v1.0.

SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause

Checking out the code

Using Wakaama as library

git clone https://github.com/eclipse/wakaama.git

Working on Wakaama

When working on Wakaama itself, or intending to run the example client application, submodules must be checked out:

git clone --recurse-submodules https://github.com/eclipse/wakaama.git

Compiling

Wakaama is a highly configurable library. It is built with CMake. Look at examples/server/CMakeLists.txt for an example of how to include it.

The different settings can be configured with CMake cache variables (e.g. cmake -DLOG_LEVEL=INFO).

Mode

Wakaama supports multiple modes. At least one mode needs to be defined with CMake cache variables.

• WAKAAMA_MODE_SERVER to enable LWM2M Server interfaces.
• WAKAAMA_MODE_BOOTSTRAP_SERVER to enable LWM2M Bootstrap Server interfaces.
• WAKAAMA_MODE_CLIENT to enable LWM2M Client interfaces.

Client Settings

Wakaama supports additional client related options. These are only available if the client mode is enabled.

• WAKAAMA_CLIENT_INITIATED_BOOTSTRAP to enable LWM2M Bootstrap support in a LWM2M Client.
• WAKAAMA_CLIENT_LWM2M_V_1_0: Restrict the client code to use LwM2M version 1.0

Please note: LwM2M version 1.0 is only supported by clients, while servers are backward compatible.

Data Formats

The following data formats are configurable for Wakaama:

• WAKAAMA_DATA_TLV to enable TLV payload support (implicit except for LWM2M 1.1 clients)
• WAKAAMA_DATA_JSON to enable JSON payload support (implicit when defining LWM2M_SERVER_MODE)
• WAKAAMA_DATA_SENML_JSON to enable SenML JSON payload support (implicit for LWM2M 1.1 or greater when defining LWM2M_SERVER_MODE or LWM2M_BOOTSTRAP_SERVER_MODE)
• WAKAAMA_DATA_SENML_CBOR to enable SenML CBOR payload support (implicit for LWM2M 1.1 or greater when defining LWM2M_SERVER_MODE or LWM2M_BOOTSTRAP_SERVER_MODE)
• WAKAAMA_DATA_SENML_CBOR_FLOAT16_SUPPORT to enable 16-bit floating point encoding support in CBOR.
• WAKAAMA_DATA_OLD_CONTENT_FORMAT to support the deprecated content format values for TLV and JSON.

CoAP Settings

• WAKAAMA_COAP_RAW_BLOCK1_REQUESTS For low memory client devices where it is not possible to keep a large post or put request in memory to be parsed (typically a firmware write). This option enable each unprocessed block 1 payload to be passed to the application, typically to be stored to a flash memory.
• WAKAAMA_COAP_DEFAULT_BLOCK_SIZE CoAP block size used by CoAP layer when performing block-wise transfers. Possible values: 16, 32, 64, 128, 256, 512 and 1024. Defaults to 1024.

Logging

The logging infrastructure can be configured with CMake cache variables (e.g. cmake -DWAKAAMA_LOG_LEVEL=INFO).

• WAKAAMA_LOG_LEVEL: Lowest log level to be enabled. Higher levels are also enabled.
  • One of: DBG, INFO, WARN, ERR, FATAL, LOG_DISABLED (default)
• WAKAAMA_LOG_CUSTOM_HANDLER: Set this define to provide a custom handler function for log entries. See the default implementation for details.
• WAKAAMA_LOG_MAX_MSG_TXT_SIZE: The max. size of the formatted log message. This is only the message without additional data like severity and function name.

Transport

• WAKAAMA_TRANSPORT: Select the implementation of the transport layer. One of:
  • POSIX_UDP: A simple UDP implementation using the POSIX socket API.
  • TINYDTLS: Use DTLS with the 'tinydtls' library.
  • NONE: No transport layer is provided.

If NONE is chosen, the user of Wakaama needs to implement a custom transport layer. Check the available implementations for more information.

Platform

• WAKAAMA_PLATFORM: Select the implementation of the platform abstraction layer, one of:
  • POSIX: An implementation using the POSIX API.
  • NONE: No platform abstraction layer is provided.

If NONE is chosen, the user of Wakaama needs to implement a custom platform abstraction layer. Check the available POSIX implementation for more information.

Command Line

Wakaama provides a simple CLI library. It can be enabled with:

• WAKAAMA_CLI: If enabled the command line library is added to Wakaama (default: disabled)

Development

Dependencies and Tools

• Mandatory:
  • Compiler: GCC and/or Clang
• Optional (but strongly recommended):
  • Build system generator: CMake 3.21+
  • Version control system: Git (and a GitHub account)
  • Git commit message linter: gitlint
  • Build system: ninja
  • C code formatting: clang-format, version 14
  • CMake list files formatting: cmake-format, version 0.6.13
  • Unit testing: CUnit

On Ubuntu 20.04, used in CI, the dependencies can be installed as such:

• apt install build-essential clang-format clang-format-14 clang-tools-14 cmake gcovr git libcunit1-dev ninja-build python3-pip
• pip3 install -r tools/requirements-compliance.txt

For macOS the development dependencies can be installed as such:

brew install automake clang-format cmake cunit gcc gitlint gnu-getopt make ninja

Code formatting

C

New C code must be formatted with clang-format.

The style is based on the LLVM style, but with 4 instead of 2 spaces indentation and allowing for 120 instead of 80 characters per line.

To check if your code matches the expected style, the following commands are helpful:

• git clang-format-14 --diff: Show what needs to be changed to match the expected code style
• git clang-format-14: Apply all needed changes directly
• git clang-format-14 --commit main: Fix code style for all changes since main

If existing code gets reformatted, this must be done in a separate commit. Its commit id has to be added to the file .git-blame-ignore-revs and committed in yet another commit.

CMake

All CMake code must be formatted with cmake-format.

To check if your code matches the expected style, the following commands are helpful:

• tools/ci/run_ci.sh --run-cmake-format: Test all CMake files, print offending ones
• cmake-format --in-place <unformatted-file>: Apply all needed changes directly to

Running CI tests locally

To avoid unneeded load on the GitHub infrastructure, please consider running tools/ci/run_ci.sh --all before pushing.

Running integration tests locally

cd wakaama
tools/ci/run_ci.sh --run-build
pytest -v tests/integration

Examples

The examples can be enabled (or disabled) with the CMake cache variable WAKAAMA_ENABLE_EXAMPLES (e.g. cmake -DWAKAAMA_ENABLE_EXAMPLES=OFF).

There are some example applications provided to test the server, client and bootstrap capabilities of Wakaama. The following recipes assume you are on a unix like platform and you have cmake and make installed.

Server example

• cmake -S examples/server -B build-server
• cmake --build build-server
• ./build-server/lwm2mserver [Options]

The lwm2mserver listens on UDP port 5683. It features a basic command line interface. Type 'help' for a list of supported commands.

Options are:

Usage: lwm2mserver [OPTION]
Launch a LWM2M server on localhost.

Options:
  -4		Use IPv4 connection. Default: IPv6 connection
  -l PORT	Set the local UDP port of the Server. Default: 5683
  -S BYTES	CoAP block size. Options: 16, 32, 64, 128, 256, 512, 1024. Default: 1024

Test client example

• cmake -S examples/client -B build-client -DWAKAAMA_MODE_CLIENT=ON
• cmake --build build-client
• ./build-client/lwm2mclient [Options]

Next to lwm2mclient a DTLS enabled variant named lwm2mclient_tinydtls gets built.

The lwm2mclient features nine LWM2M objects:

• Security Object (id: 0)

• Server Object (id: 1)

• Access Control Object (id: 2) as a skeleton

• Device Object (id: 3) containing hard-coded values from the Example LWM2M Client of Appendix E of the LWM2M Technical Specification.

• Connectivity Monitoring Object (id: 4) as a skeleton

• Firmware Update Object (id: 5) as a skeleton.

• Location Object (id: 6) as a skeleton.

• Connectivity Statistics Object (id: 7) as a skeleton.

• Test Object (id: 31024) with the following description:

                      Multiple
     Object |  ID   | Instances | Mandatory |
      Test  | 31024 |    Yes    |    No     |
  
      Resources:
                  Supported    Multiple
      Name | ID | Operations | Instances | Mandatory |  Type   | Range |
      test |  1 |    R/W     |    No     |    Yes    | Integer | 0-255 |
      exec |  2 |     E      |    No     |    Yes    |         |       |
      dec  |  3 |    R/W     |    No     |    Yes    |  Float  |       |
  

The lwm2mclient opens UDP port 56830 and tries to register to a LWM2M Server at 127.0.0.1:5683. It features a basic command line interface. Type 'help' for a list of supported commands.

Options are:

Usage: lwm2mclient [OPTION]
Launch a LWM2M client.
Options:
  -n NAME	Set the endpoint name of the Client. Default: testlwm2mclient
  -l PORT	Set the local UDP port of the Client. Default: 56830
  -h HOST	Set the hostname of the LWM2M Server to connect to. Default: localhost
  -p PORT	Set the port of the LWM2M Server to connect to. Default: 5683
  -4		Use IPv4 connection. Default: IPv6 connection
  -t TIME	Set the lifetime of the Client. Default: 300
  -b		Bootstrap requested.
  -c		Change battery level over time.
  -S BYTES	CoAP block size. Options: 16, 32, 64, 128, 256, 512, 1024. Default: 1024

Additional values for the lwm2mclient_tinydtls binary:

  -i Set the device management or bootstrap server PSK identity. If not set use none secure mode
  -s Set the device management or bootstrap server Pre-Shared-Key. If not set use none secure mode

To launch a bootstrap session: ./lwm2mclient -b

Simpler test client example

• cmake -S examples/lightclient -B build-lightclient
• cmake --build build-lightclient
• ./build-lightclient/lightclient [Options]

The lightclient is much simpler that the lwm2mclient and features only four LWM2M objects:

• Security Object (id: 0)
• Server Object (id: 1)
• Device Object (id: 3) containing hard-coded values from the Example LWM2M Client of Appendix E of the LWM2M Technical Specification.
• Test Object (id: 31024) from the lwm2mclient as described above.

The lightclient does not feature any command-line interface.

Options are:

Usage: lwm2mclient [OPTION]
Launch a LWM2M client.
Options:
  -n NAME	Set the endpoint name of the Client. Default: testlightclient
  -l PORT	Set the local UDP port of the Client. Default: 56830
  -4		Use IPv4 connection. Default: IPv6 connection
  -S BYTES	CoAP block size. Options: 16, 32, 64, 128, 256, 512, 1024. Default: 1024

Bootstrap Server example

• cmake -S examples/bootstrap_server -B build-bootstrap
• cmake --build build-bootstrap
• ./build-bootstrap/bootstrap_server [Options]

Refer to examples/bootstrap_server/README for more information.