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.
`gnrc_sixlowpan_frag_rb_base_rm()` cleans up the intervals which is part
of `gnrc_sixlowpan_frag_rb`, not `gnrc_sixlowpan_frag`, so when the
`gnrc_sixlowpan_frag` is not compiled in, but `gnrc_sixlowpan_frag_rb`,
the intervals allocated in the reassembly buffer and inherited by the
virtual reassembly buffer are never released.
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.
Right now 'ipv6_addr_split_iface' assumes that the interface specifier
will always be a number (based on GNRC way of identifying interfaces),
but this may not be always the case.In order to be able to use the
Network Interface API, interfaces should be referred by their name.
This changes 'ipv6_addr_split_iface' so it returns a pointer to the
string that specifies the interface.
45f7966 made the `src_len` field the "emptiness signifier" for the VRB.
However, when `gnrc_sixlowpan_frag` is compiled in, the remove function
`gnrc_sixlowpan_frag_vrb_rm()` does not set the `src_len` to zero,
resulting in already deleted entry to be recognized as non-empty.
This allows to set a timer between the completion of a datagram in the
reassembly buffer and the deletion of the corresponding reassembly
buffer entry. This allows to ignore potentially late incoming link-layer
duplicates of fragments of the datagram that then will have the
reassembly buffer entry be blocked.
This was noted in this [discussion] for classic 6LoWPAN reassembly (and
minimal fragment forwarding) and is recommended in the current
[selective fragment recovery draft][SFR draft].
[discussion]: https://mailarchive.ietf.org/arch/msg/6lo/Ez0tzZDqawVn6AFhYzAFWUOtJns
[SFR draft]: https://tools.ietf.org/html/draft-ietf-6lo-fragment-recovery-07#section-6
This imports the protocol parameters for Selective Fragment Recovery
(SFR). For the values I took some educated guesses based on my
experience with previous experimentation with fragment forwarding.
The defines currently are based on [draft v7].
[draft v7]: https://tools.ietf.org/html/draft-ietf-6lo-fragment-recovery-07#section-7.1
fixup! gnrc_sixlowpan_frag: initial import of SRF parameters
The name `fragment_msg` or `frag_msg`/`msg_frag` always to me was a bit
misplaced, as it basically implements an asynchronous fragmentation
buffer and doesn't necessarily have anything to do with messages.
This change
1. changes the name to `fb` (for fragmentation buffer)
2. factors its code out to its own sub-module so it can be re-used by
other 6LoWPAN fragmentation schemes like [Selective Fragment
Recovery]
[Selective Fragment Recovery]: https://tools.ietf.org/html/draft-ietf-6lo-fragment-recovery-05
This module was intended to be a test framework for GNRC but it never
really got used. It was not maintained for 3 years. It will be removed
after 2020.07 release at the latest.
The functions now are semantic distinct:
- gnrc_netif_is_6lo(): the interface is a 6Lo interface
- gnrc_netif_is_6ln(): the interface is using Neighbor Discovery
according to RFC 6775
Preparation step to introduce a semantic difference between an
interface being a 6Lo interface and a 6LN according to RFC 6775 [[1]]
(i.e. performs Neighbor Discovery as defined there).
[1]: https://tools.ietf.org/html/rfc6775#section-2
Rather than dispatching the packet automatically once it is complete,
`gnrc_sixlowpan_frag_rb_add()` now only returns success, and leaves it
to the caller to dispatch the packet.
Due to some changes to the minimal forwarding draft and in preparation
for Selective Fragment Recovery some changes to the VRB API were
needed. Now the index of a VRB entry is only (L2 src, tag) not as
before (L2 src, L2 dst, length, tag).
I know that the current `rbuf_base` causes waste, as all the fields not
used by the new index are effectively not used by the VRB. I'd like to
fix that however in a later change, since that also requires some
modifications of the classic reassembly buffer, and thus would
complicate the review and testing of the change.
Sources for the index change:
- https://tools.ietf.org/html/draft-ietf-6lo-minimal-fragment-04#section-1
- https://mailarchive.ietf.org/arch/browse/6lo/?gbt=1&index=DLCTxC2X4bRNtYPHhtEkavMWlz4
