When reworking the reception of IPv6 packets I reset a previously set
`ipv6` snip as follows when the IPv6 extension handler returns a
packet (see first hunk of this commit):
```C
ipv6 = pkt->next->next
```
With `gnrc_ipv6_ext` this makes *somewhat* sense, `pkt->next` was
previously equal to `ipv6` and after the function call `pkt->next`
is the marked extension header, while `pkt->next->next` is the IPv6
header. However, since `ipv6` is already write-protected i.e.
`ipv6->users == 1` (see ll. 665-675), any additional call of
`gnrc_pktbuf_start_write()` [won't][start-write-doc] duplicate the
packet. In fact, the only `gnrc_pktbuf_start_write()` in
`gnrc_ipv6_ext` is used to send the *result* to the subscribers of that
extension header type, leaving the original packet unchanged for the
caller. As such `ipv6` remains the pointer to the IPv6 header whether
we set it in the line above or not. So we actually don't need that
line.
However, the extension header handling also returns a packet when
`gnrc_ipv6_ext` is not compiled in. In that case it is just a dummy
define that returns the packet you give provide it which means that
this still holds true: `pkt->next == ipv6`.
So setting `ipv6` in this case is actually harmful, as `ipv6` now
points to the NETIF header [following the IPv6 header][pkt-structure]
in the packet and this causes the `user` counter of that NETIF header
`hdr` to be decremented if `hdr->users > 1` in the write-protection I
removed in hunk 2 of this commit:
```C
/* pkt might not be writable yet, if header was given above */
ipv6 = gnrc_pktbuf_start_write(ipv6);
if (ipv6 == NULL) {
DEBUG("ipv6: unable to get write access to packet: dropping it\n");
gnrc_pktbuf_release(pkt);
return;
}
```
But as we already established, `ipv6->users` is already 1, so we don't
actually need the write protection here either.
Since the packet stays unchanged after the `ipv6` snip, we also don't
need to re-search for `netif_hdr` after the other two lines are
removed.
[start-write-doc]: https://doc.riot-os.org/group__net__gnrc__pktbuf.html#ga640418467294ae3d408c109ab27bd617
[pkt-structure]: https://doc.riot-os.org/group__net__gnrc__pkt.html#ga278e783e56a5ee6f1bd7b81077ed82a7
Summary for Users
=================
Deprecation is scheduled for 2020.01.
Users which depend on this module and cannot switch libraries may copy
the code into to their own application.
As expressed in PR #11724, the UBJSON module has issues which are not easy
or worth fixing.
Before removing the module, it should be marked as deprecated to give users
time to either migrate to another library, or copy the code to their own
private repo.
The deprecation warning has been supressed from the unit tests. This has the
ugly side-effect of supressing deprecation warning in other unit tests too,
but that should not last long, only until the module is finally deleted.
The `addr` parameter of the NIB's `_handle_dad()` function can come
from anywhere (e.g. in the fallback to classic SLAAC the destination
address of the IP header is used), so putting that pointer in a timer
is not a good idea. Instead we use the version of the address that is
stored within the interface.
The API of `tsrb` was changed because of confusing type situations.
This API change takes this API change of changing `char` to `uint8_t`
up a level. Since `isrpipe` most often is used together with
`periph_uart` this change even is beneficial, as `periph_uart` also
uses `uint8_t` instead of `char`.
Having the input type `char` makes the output of `tsrb_get_one()`
incomparable to the input of `tsrb_add_one()`. By changing it to
`uint8_t` we not only definitively fix it to an octet, but also ensure
that the input and output are the same.
To read float number from stdin, add "-u scanf_float"
option to the linker.
This option is setup using a pseudomodule as it is already done for
printf_float.
Just add to your Makefile:
USEMODULE += scanf_float
Signed-off-by: Gilles DOFFE <g.doffe@gmail.com>
`_demux()` might change `pkt->data` in all kind of ways (moving it due
to `gnrc_pktbuf_mark()`, though unlikely; releasing it, because e.g. it
starts with a fragment header that marks a fragmented packet containing
only one fragment, etc.) so accessing the pointer *after* calling
`_demux()` is somewhat playing with fire. This change avoids this by
storing the value of `ext_hdr->nh` (all we are interested in here) in a
temporary variable that then is used to set the out-parameter `nh`.
`protnum` needs to be unchanged before the call to `_demux()` as it was
set by the previous iteration and determines what extension header
actually is handled.
- If riotboot_slot wasn't included explicitly, e.g. when
only setting FEATURES_REQUIRED+=riotboot riotboot slot
definitions were not present and therefore build failed.
