If a new L2 connection was established, the node should be inserted in
the neighbor cache.
For 6LN nodes, NIB will never start the usual neighbor discovery process
because it can directly resolve the link-layer address from the IPv6
address. Thus we have to manually add such nodes to the NC by building
the IPv6 address from the L2 address.
If a L2 connection closed, the node is removed again from the NC.
Router Advertisements are enabled automatically for routing nodes
as soon as they obtain a prefix (e.g. via DHCPv6, UHCP, …).
Enabling router advertisements without a prefix to advertise is
wrong and causes no router solicitations to be send on an upstream
interface.
Also from https://www.rfc-editor.org/rfc/rfc4861#section-6.2.1
Note that AdvSendAdvertisements MUST be FALSE by
default so that a node will not accidentally start
acting as a router unless it is explicitly
configured by system management to send Router
Advertisements.
18477: gnrc_static: add static network configuration r=miri64 a=benpicco
19101: CI: update check-labels-action r=miri64 a=kaspar030
19155: Revert "sys/pm_layered: pm_(un)block add attribute optimize(3)" r=maribu a=Teufelchen1
Revert "sys/pm_layered: pm_(un)block add attribute optimize(3) -shortens hotpath"
This reverts commit 5447203921ab39962d7d378a631a6bc048e7f30b.
### Contribution description
Compiling `examples/gnrc_networking_mac` using `TOOLCHAIN=llvm` yields the following error:
```
RIOT/sys/pm_layered/pm.c:77:16: error: unknown attribute 'optimize' ignored [-Werror,-Wunknown-attributes]
__attribute__((optimize(3)))
```
As indicated, this is because the attribute `optimize` is GCC only and not present in LLVM.
Compare the manpages of [GCC](https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html) and [LLVM](https://clang.llvm.org/docs/AttributeReference.html).
### Testing procedure
Since this should only affect performance and not behavior, no special testing is needed. I am not aware of any tests in RIOT which could verify that assumption.
### Issues/PRs references
Introduced in #18846
There is another instance of this attribute being used in[ shell_lock.c](6fb340d654/sys/shell_lock/shell_lock.c (L80)). Since the usage is security related, I omit it from this PR.
Co-authored-by: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Co-authored-by: Kaspar Schleiser <kaspar@schleiser.de>
Co-authored-by: Teufelchen1 <bennet.blischke@haw-hamburg.de>
Sending a RA with ltime = 0 does not get us added to the default router
list, but the options (and therefore the RIO) are still parsed.
This even appears to work with Linux as a receiver.
