The comment exists since the introduction of the [original
implementation], but its meaning is unclear and misleading, as the code
doesn't do anything with link-local.
[original implementation]: https://github.com/RIOT-OS/RIOT/pull/3561
Rule 2 of the source address algorithm outlined in [RFC6724] states the
possible source addresses must also be compared among each other:
> Rule 2: Prefer appropriate scope.
> If Scope(SA) < Scope(SB): If Scope(SA) < Scope(D), then prefer SB and
> otherwise prefer SA. Similarly, if Scope(SB) < Scope(SA): If
> Scope(SB) < Scope(D), then prefer SA and otherwise prefer SB.
Our current implementation doesn't do that. It just checks if the scope
of a possible source is lesser than the scope of the destination
(which involves the second "If" in the rule).
This fix grants points according to the scope of an address. If the
scope matches, they get the highest points, ensuring that the selected
source will always be reachable from the destination.
[RFC6724]: https://tools.ietf.org/html/rfc6724
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.
A pointer is not 32 bit on all platforms.
Since gnrc_lwmac only stores 16 bit in the pointer variable it is
still save to cast like this even on AVR, but cast to uintptr_t
instead of uint32_t.
fixes#12869
When the destination address is the loopback address (`::1`) in GNRC
the selected network interface typically is `NULL`, as with GNRC no
loopback interface de facto exists. So the assertion when checking if
the source address is valid if `netif != NULL` fails on that check.
This change fixes that issue by checking if the destination address is
the loopback address, before checking the validity of the source
address.
The RTT callback for a super-frame cycle uses the `arg` pointer to set
the message value that then is handed to the GoMacH thread. However,
in both instances the timer is scheduled the constant
`GNRC_GOMACH_EVENT_RTT_NEW_CYCLE` is provided. This means the argument
is not really necessary.
This fits with the semantics of this function which doesn't provide or
uses any state of the reassembly buffer provided by the user, but finds
the entry itself and then removes it. This gives the user no chance to
remove the packet in the reassembly buffer entry, so
`gnrc_sixlowpan_frag_rb_rm_by_datagram()` has to release the packet
(other than `gnrc_sixlowpan_frag_rb_remove()` where not releasing the
packet is desired as it might be handed up to an upper layer).
