Typically a stack needs to add the callback for a sock as a member of
its respective `sock` type so `sock_types.h` needs to include
`net/sock/async.h` at the moment. As those however include
`net/sock/<prot>.h`, which in turn include `sock_types.h`, we create a
cyclic dependency.
This fix resolves this cyclic dependency, by putting the callback
definitions in its own header that then in turn can be also included
by `sock_types.h`.
Having the definitions sit in the `net/gnrc/sixlowpan/frag.h` header
does not make much sense, when using Selective Fragment Forwarding
(and the fragmentation buffer already includes a
`net/gnrc/sixlowpan/frag/stats.h` header), so they are moved to their
own header. Since with this change it makes more sense to have the
statistics stored in their own sub-module, the pseudo-module is also
actualized.
The ubjson module has a number of quality defects and is unsafe.
Considering CBOR is popular, standarized and supported in RIOT and that
the ubjson implementation is a home-grown one whose API will likely be
unfamiliar to new users, I propose to delete it.
This removal, of course, dows not have to be NOW. We can deprecate it for
one or two releases before.
What's wrong with this module?
- Unsafe: the parsing is done recursively. This is embedded in the API, so it
is not possible to fix it without changing the API. A document with too much
nesting can cause a stack overflow.
- Does not validate writing: it is possible to produce invalid output. From
the docs:
> The library won't complain if you write multiple values that are not
> inside an array or object. The result will just not be properly serialized.
- Poorly tested. As shown by #11702, #11703 the tests were not even detecting
that a False was stored as True.
- In line with the previous remark, see
68dc5b0d6e/tests/unittests/tests-ubjson/tests-ubjson.c (L66-L77)
Why is the following code in the unit tests??
```c
irq_disable();
sched_set_status(data->main_thread, STATUS_PENDING);
```
- #2175 is still unfixed after 3.5 years.
- Code quality. The code has multiline macros that assign variables and
return. See c332514875/sys/ubjson/ubjson-write.c (L34-L41)
Can we mark it as deprecated this release and sweep it in the following one?
Preprocesor fails to evaluate the if condicion on L91-92 because
RTT_FREQUENCY is not defined, and therefore a division by 0 occurs.
TO avoid this replicate the RTT_FREQUENCY undefined warning.
Currently the bitfield type mixes up the order of bits: While the byte
order is big-endian (most significant byte first), the bit order of each
single byte within the bitfield is little-endian (most significant bit
last). While this isn't a problem for most applications of the bitfield
type it becomes one when sending the bitfield over the network (as done
e.g. in the [ACKs of Selective Fragment Recovery][SFR-ACKs]).
This change unifies byte order and bit order to both be most
significant bX first.
[SFR-ACKs]: https://tools.ietf.org/html/draft-ietf-6lo-fragment-recovery-07
