The function to infer the link-layer address length from the length of
a S/TLLAO is very dependent on the IPv6 over X specification and thus
should be grouped with the other IP over X functions.
When having a non-6LN interface and a 6LN interface (e.g. on a border
router) the assertion can hit when a Router Advertisement is received.
This makes the check an `if` statement rather than an assertion, to
account for that case.
Co-authored-by: Gunar Schorcht <gunar@schorcht.net>
Without this the first packet to a new link-local address will not be
delivered in non-6Lo environments, since the interface is not provided.
With this change, if an internet was provided to the address resolver it
will be stored within an allocated `gnrc_netif_hdr_t`.
At this point [IPv6 already striped](netif strip) the packet of its
netif header, so there is no risk that there will be to, in case it was
provided and the `netif` came from its existence.
Our `gnrc_minimal` example configures the link-local address from the
IEEE 802.15.4 short address since it does not include 6Lo-ND.
This causes the application to be incompatible with our other GNRC
application that do include 6Lo-ND, since it [assumes][1] the link-local
address to be based on the EUI-64 for address resolution.
This enforces long addresses (aka EUI-64) for all IEEE 802.15.4 devices
when IPv6 is compiled in so `gnrc_minimal` is compatible again to the
rest.
Fixes#9910
[1]: https://tools.ietf.org/html/rfc6775#section-5.2
Linux doesn't have ARO support at the moment so this is a workaround to
try to speak 6Lo-ND while still being able to do DAD with a border
router that doesn't.
Parts of [RFC4862] were already implemented when NDP via the NIB was
first implemented. This change just includes the DAD portion of
[RFC4862]. This should be enough to make RIOT fully RFC4862 compliant.
[RFC4862]: https://tools.ietf.org/html/rfc4862
With the previous fix, we only have to register addresses that are not
VALID yet on reception of router advertisements. This removes the need
for the hacky `GNRC_NETIF_FLAGS_6LO_ADDRS_REG` flag that was only
introduced to prevent unnecessary re-registration.
The whole address registration looses its point if all addresses are
marked valid from the get-go. With this fix non-link-local addresses
are first marked TENTATIVE and only after successful registration
marked as VALID. Link-local addresses are assumed to always be VALID.
[RFC6775] only talks of *routers* processing router advertisements,
with regards of discarding them if they do not contain an ABRO.
Additionally, this change makes configuration of tests setups a lot
easier, where one note is a router distributing a prefix and the other
is a host to be configured with the RA. Just do the following on the
router:
```
> ifconfig <if> add <GUA>
> ifconfig <if> rtr_adv
```
e voilà! In current master both nodes would have needed to be compiled
with `GNRC_IPV6_NIB_CONF_MULTIHOP_P6C=0`.
[RFC6775]: https://tools.ietf.org/html/rfc6775#section-8.1.3
This fix
* assures that the periodicity of the final router advertisements is
kept (so that no administrative change e.g. adding prefixes to the
prefix list causes additional RAs outside the rate limitation)
* removes all administrative options (PIO, ABRO, 6CO) from final router
advertisements (with router lifetime == 0)
I applied the following terminology and changed the wording in the doc
accordingly:
* must not: If the parameter is of the value it *must not* be it either
hits an assert or crashes the system.
* may not: The value can be that value, but the function will return an
error.
This renames the following functions
* `gnrc_netif_ipv6_addr_add()`
* `gnrc_netif_ipv6_addr_remove()`
* `gnrc_netif_ipv6_group_join()`
* `gnrc_netif_ipv6_group_leave()`
by appending the suffix `_internal`.
\## Reasoning
I'd like to provide a helper function for the *public* equivalent using
`gnrc_netapi_set()`, and those names are to nice to not be taken for
those.
\## Procedure
I used a combination of `git grep` and `sed` to do this and fixed the
alignment in the result of some cases by hand.
```sh
git grep --name-only "\<gnrc_netif_ipv6_\(addr\|group\)_\(add\|remove\|join\|leave\)\>" | \
xargs sed -i 's/\<gnrc_netif_ipv6_\(addr\|group\)_\(add\|remove\|join\|leave\)/\0_internal/g'
```
