Now that the security data can be loaded into and used from the
security / server objects, we can add support for LwM2M bootstrap.
This is a mode where initially a connection can be made to a server
which can update several LwM2M (including security and server
data) and then trigger a "bootstrap complete". Once this happens
the client will start it's connection process over but now with
the new information.
Signed-off-by: Michael Scott <mike@foundries.io>
Origin: SICS-IoT / Contiki OS
URL: https://github.com/sics-iot/lwm2m-contiki/tree/lwm2m-standalone-dtls
commit: d07b0bcd77ec7e8b93787669507f3d86cfbea64a
Purpose: Introduction of LwM2M client library.
Maintained-by: Zephyr
Lightweight Machine-to-Machine (LwM2M) is a protocol stack extension
of the Constrained Application Protocol (CoAP) which uses UDP
transmission packets.
This library was based on source worked on by Joakim Eriksson,
Niclas Finne and Joel Hoglund which was adopted by Contiki and then
later revamped to work as a stand-alone library.
A VERY high level summary of the changes made:
- [ALL] sources were re-formatted to Zephyr coding standards
- [engine] The engine portion was re-written due to the heavy reliance
on ER-CoAP APIs which are not compatible to the Zephyr CoAP APIs as
well as other Zephyr specific needs.
- [engine] All LWM2M/IPSO object data is now abstracted into resource
data which stores information like the data type, length, callbacks
to help with read/write. The engine modifies this data directly (or
makes callbacks) instead of all of the logic for this living in each
object's code. (This wasn't scaling well as I was implementing
changes).
- [engine] Related to the above change, I also added a generic set of
getter/setter functions that user applications can call to change
the object data instead of having to add getter/setting methods in
each object.
- [engine] The original sources shared the engine's context structure
quite extensively causing a problem with portability. I broke up the
context into it's individual parts: LWM2M path data, input data and
output data and pass only the needed data into each set of APIs.
- [content format read/writer] sources were re-organized into single
.c/h files per content formatter.
- [content format read/writer] sources were re-written where necessary
to remove the sharing of the lwm2m engine's context and instead only
requires the path and input or output data specific to it's
function.
- [LwM2M objects] re-written using the new engine's abstractions
Signed-off-by: Michael Scott <michael.scott@linaro.org>
