Since IPHC also manipulates the total number of bytes of a received
datagram (by decompressing it), this also needs to be exposed. I guess
I was too focused on introducing a *generic* packet buffer for a future
virtual reassembly buffer (where it isn't needed, but so isn't `pkt` to
be honest), that I totally forgot about it in #9352.
This fixes an alignment issue I encountered in the static version of
the packet buffer.
The bug is caused by a race-condition where a certain order of
operations leads to a chunk being released according to the
byte-alignment of the platform, but overlapping potential space for
a future `_unused_t` struct e.g. (x mark allocated regions):
Future leak of size sizeof(_unused_t) Time
v |
+------------+-----+--------------------+ |
|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx| +
+------------+-----+--------------------+ |
|
+------------+--+--+--------------------+ |
| |xxxxxxxxxxxxxxxxxxxxxxx| +
+------------+--+--+--------------------+ |
|
+-----+------+--+--+--------------------+ |
|xxxxx| |xxxxxxxxxxxxxxxxxxxxxxx| +
+-----+------+--+--+--------------------+ |
|
+-----+------+-----+---------+----------+ |
|xxxxx| |xxxxxxxxxx| +
+-----+------+-----+---------+----------+ |
|
+-----+------+-----+--------------------+ |
|xxxxx| |xxxxxxxxxxxxxxxxxxxxxxxxxx| +
+-----+------+-----+--------------------+ |
|
+------------+-----+--------------------+ |
|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx| +
+------------+-----+--------------------+ |
|
+------------+-----+--------------------+ |
|xxxxxxxxxxxxxxxxxx| | +
+------------+-----+--------------------+ |
|
+------------+-----+--------------------+ |
| |xxxxx| | +
+------------+-----+--------------------+ |
v
Sadly, I wasn't able to create a reproducable unittest that show-cases
this corner-case, since I don't understand the order of operations that
cause this one 100%, but the bug is reproducable (but also not
reliably) by sending large (i.e. fragmented) packets to a 6Lo-enabled
host from more than 1 host simultaneously (use `gnrc_pktbuf_cmd` to
check).
By making the size of `_unused_t` the only condition for alignment,
this bug is fixed.
- Added unit tests for new integer only arithmetic
- Temperature conversion differs at most 0.01°C from double arithmetic
- Humidity conversions differs at most 0.1% from double arithmetic
- Use RIOT's GPIO interface to access the sensor to increase portability
- Changed API to allow more than one sensor per board
- Added `sht1x_params.h` that specifies how the sensors is connected - each
board can overwrite default settings by #defining SHT1X_PARAM_CLK and
SHT1X_PARAM_DATA
- Changed arithmetic to use integer calculations only instead of floating point
arithmetic
- Added support for checking the CRC sum
- Allow optional skipping of the CRC check to speed up measuring
- Added support for advanced features like reducing the resolution and skipping
calibration to speed up measuring
- Allow specifying the supply voltage of sensor which heavily influences the
temperature result (and use that information to calculate the correct
temperature)
- Reset sensor on initialization to bring it in a well known state
- Support for the obscure heater feature. (Can be useful to check the
temperature sensor?)
- Updated old SHT11 shell commands to the new driver interface, thus allowing
more than one SHT10/11/15 sensor to be used
- Added new shell command to allow full configuration of all attached SHT1x
sensors
- Removed old command for setting the SHT11 temperature offset, as this feature
is implemented in the new configuration command
