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 master branch. Release 1.0 is not supported anymore.

Badges

Source Layout

-+- core                   (the LWM2M engine)
 |
 +- coap                   (CoAP stack adaptation)
 |    |
 |    +- er-coap-13        (Modified Erbium's CoAP engine from
 |                          https://web.archive.org/web/20180316172739/http://people.inf.ethz.ch/mkovatsc/erbium.php)
 |
 +- data                   (data formats serialization/deserialization)
 |
 +- tests                  (test cases)
 |    |
 |    +- integration       (pytest based integration tests implementing the OMA-ETS-LightweightM2M-V1_1-20190912-D specification
 |                          https://www.openmobilealliance.org/release/LightweightM2M/ETS/OMA-ETS-LightweightM2M-V1_1-20190912-D.pdf)
 +- examples
      |
      +- bootstrap_server  (a command-line LWM2M bootstrap server)
      |
      +- client            (a command-line LWM2M client with several test objects)
      |
      +- lightclient       (a very simple command-line LWM2M client with several test objects)
      |
      +- server            (a command-line LWM2M server)
      |
      +- shared            (utility functions for connection handling and command-
                            line interface)

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 not a library but files to be built with an application. Wakaama uses CMake >= 3.13. Look at examples/server/CMakeLists.txt for an example of how to include it. Several preprocessor definitions are supported:

• Endianness: Exactly one has to be defined.
  • LWM2M_BIG_ENDIAN if your target platform uses big-endian format.
  • LWM2M_LITTLE_ENDIAN if your target platform uses little-endian format.
• Mode: One or multiple modes have to be defined.
  • LWM2M_CLIENT_MODE to enable LWM2M Client interfaces.
  • LWM2M_SERVER_MODE to enable LWM2M Server interfaces.
  • LWM2M_BOOTSTRAP_SERVER_MODE to enable LWM2M Bootstrap Server interfaces.
• LWM2M_BOOTSTRAP to enable LWM2M Bootstrap support in a LWM2M Client.
• LWM2M_SUPPORT_TLV to enable TLV payload support (implicit except for LWM2M 1.1 clients)
• LWM2M_SUPPORT_JSON to enable JSON payload support (implicit when defining LWM2M_SERVER_MODE)
• LWM2M_SUPPORT_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)
• LWM2M_OLD_CONTENT_FORMAT_SUPPORT to support the deprecated content format values for TLV and JSON.
• Version 1.1 of LWM2M is supported per default, but can be constrained to older versions:
  • LWM2M_VERSION_1_0 to support only version 1.0 Please note: Clients support only the specified version, while servers are backward compatible.
• LWM2M_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.
• LWM2M_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.

Development

Dependencies and Tools

• Mandatory:
  • Compiler: GCC and/or Clang
• Optional (but strongly recommended):
  • Build system generator: CMake 3.13+
  • 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

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 master: Fix code style for all changes since master

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

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

• Create a build directory and change to that.
• cmake [wakaama directory]/examples/server
• make
• ./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

• Create a build directory and change to that.
• cmake [wakaama directory]/examples/client
• make
• ./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

In the any directory, run the following commands:

• Create a build directory and change to that.
• cmake [wakaama directory]/examples/lightclient
• make
• ./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

• Create a build directory and change to that.
• cmake [wakaama directory]/examples/bootstrap_server
• make
• ./bootstrap_server [Options]

Refer to examples/bootstrap_server/README for more information.