LWM2M for device management

[zephyrbot]

Reported by Anas Nashif:

As a Zephyr developer, I would Zephyr to include a library to support LWM2M device functionality, so that my product can be managed from an LWM2M server.

Lightweight M2M from the Open Mobile Alliance is fast becoming the global industry standard for M2M device management for the development of a fast, deployable, client-server specification to provide machine-to-machine service. OMA Lightweight M2M is designed to:

• Provide Device Management functionality over sensor or cellular networks
• Transfer service data from the network to devices
• Extend to meet the requirements of most any application

Zephyr support for LWM2M Device Functionality will include:

• Simple Object based resource model
• Resource operations of creation/retrieval/update/deletion/configuration of attribute
• Resource observation/notification
• TLV/JSON/Plain Text/Opaque data format support
• UDP transport layer support
• DTLS based security
• Queue mode for NAT/Firewall environment
• Multiple LWM2M Server support
• Basic M2M functionalities: LWM2M Server, Access Control, Device, Connectivity, Firmware Update, Location, Connectivity Statistics

(Imported from Jira ZEP-216)

[zephyrbot]

by Joakim Eriksson:

The Queue mode is not only useful for firewalls and NAT but also even more important for sleepy devices running LWM2M.

[zephyrbot]

by ethan gao:

This story contains many features to implement, is there any RFC for it now ?

[zephyrbot]

by Michael Scott:

FYI, I'm working on a Zephyr port of Joakim Eriksson work which was previously merged into the Contiki base back in 2016. Joakim Eriksson and others have continued to improve the library over time and I'm basing my work on the "stand alone" version here:
https://github.com/sics-iot/lwm2m-contiki/tree/lwm2m-standalone-dtls

Changes include:

• Replacement of the ER-CoAP APIs with Zephyr CoAP APIs (ZoAP) -- this the bulk of the work involved
• Minor "Zephyr-ization" of code such as using SYLISTs etc.
• Coding style changes to meet Zephyr standards
• Kconfig support for using all / some or a minimal version of the library

I still have quite a bit of work to do -- but if you're curious, I'm keeping a WIP branch based on Zephyr master here: https://github.com/mike-scott/zephyr/tree/lwm2m/subsys/net/lib/lwm2m

[zephyrbot]

by Anas Nashif:

Michael Scott can we assign this to you then? When do you think we can first see this in Zephyr?

[zephyrbot]

by Michael Scott:

Yes, please assign it to me. Re Timing: Best guess would be an RFC PR in about 2 weeks? That would be for the initial library addition supporting QEMU / K64F testing against a Leshan demo server.

[zephyrbot]

by Joakim Eriksson:

Maybe we should in the long run figure out if we could design a CoAP API that make it easy to support the lwm2m code both on top of ER-CoAP (as in Contiki) and the ZoAP - or is that a too big task? (have not checked out the ZoAP API in detail yet).

[zephyrbot]

by Michael Scott:

Initial RFC patches submitted: #712

[zephyrbot]

by Mark Linkmeyer:

Hi Michael Scott , is this story expected to be implemented in time for 1.9? Or, is it still in planning where it's not known yet if it will make it into 1.9? Thx.

[zephyrbot]

by Michael Scott:

Hi Mark Linkmeyer ,

I've just returned from holiday and this is my priority for the next 2 weeks with the intention of getting #712 merged before the 1.9 cutoff.

[zephyrbot]

by Mark Linkmeyer:

Thanks Michael Scott , and welcome back! Based on your last comment, I'm going to change the status of this story from NEW (a.k.a. "planning") to IN PROGRESS since you plan to have it done for 1.9 and you have the pull request where you're asking for feedback comments. Or, do you actually have code changes you are already submitting for code review? If so, we should set the status to CODE REVIEW. Thx.

[zephyrbot]

by Michael Scott:

Mark Linkmeyer I think CODE REVIEW is a better status. My next update to the PR will be to remove RFC tags and address feedback previously supplied. A basic code review of the RFC PR has already happened.

[zephyrbot]

by Mark Linkmeyer:

I just updated the status for you Michael Scott . Thx again.

[zephyrbot]

by Michael Scott:

Initial PR: #712 is basically ready to merge. Pending 1-2 final reviews. (Jukka Rissanen has already agreed it was ready).