Due to work combining data into the lwm2m_message structure, we no
longer need to pass the lwm2m_engine_obj parameter between
formatters and most of the operation handlers.
So, let's remove it.
Signed-off-by: Michael Scott <mike@foundries.io>
Update the parsing functions for JSON used by the JSON data
formatter and enable it in the LwM2M engine.
Signed-off-by: Michael Scott <mike@foundries.io>
The relationship between lwm2m_engine_context and lwm2m_message
has always been a tenuous one. Let's merge the 2 structures
into lwm2m_message and remove all of the extra stack variables.
This change increases SRAM usage slightly due to the
addition of the context structures to the multiple lwm2m_messages.
However, the way lwm2m_engine_context was being used off the stack
was probably creating hard to debug issues in the longterm.
Also, having all of the structures in 1 place makes sharing them
much easier later.
Signed-off-by: Michael Scott <mike@foundries.io>
Data formatters are becoming too complex for a simple do_read_op()
function to handle all in one place. Also, more data formatters are
going to be added for LwM2M v1.1 support in the future.
In order for data formatters to perform internal setup or deny
invalid requests (specific to the formatter's logic), let's
establish do_read_op_* functions in each formatter.
Once the internal processing is done, they can call back into the
more generic lwm2m_perform_read_op function.
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>
