Synchronize the RPL thread updating the RPL netstats with the RPL
shell command reading it by disabling IRQs. This will prevent printing
corrupted data on non-32bit platforms as well as printing inconsistent
data (e.g. TX count of old state in conjunction with TX bytes of new
state) for all platforms.
Co-authored-by: Martine Lenders <mail@martine-lenders.eu>
There is a repeating pattern in the struct that is split out into a
subtype in this commit. This makes handling the data easier, as now
done in the print routine.
Instead of retrieving a pointer with NETOPT_STATS, retrieve the current
data. This avoids data corruptions when reading from one thread (e.g.
the thread running the shell (ifconfig command)) while another thread
is updating it (e.g. the netif thread).
The issue affects all boards, as users typically expect the count of
TX packets and the number of TX bytes to refer to the same state. For
16 bit and 8 bit platforms even a single netstat entry can read back
corrupted.
This fixes the issue by just copying the whole netstat_t struct over
without requiring explicit locking on the user side. A multi-threaded
network stack still needs to synchronize the thread responding to
netopt_get with the thread writing to the netstat_t structure, but that
is an implementation detail no relevant to the user of the API.
The netif list is used like a stack, so it needs to be
iterated in reverse to keep the registration order.
Time complexity in O(n^2), but the the list is normally very short
(1-2 items).
Before:
```
> ifconfig
Iface 10 HWaddr: 24:0A:C4:E6:0E:9C Channel: 0 Link: down
[..]
Iface 7 HWaddr: 24:0A:C4:E6:0E:9F Link: down
[..]
```
Now they are in the increasing order:
```
> ifconfig
Iface 7 HWaddr: 24:0A:C4:E6:0E:9F Link: down
[..]
Iface 10 HWaddr: 24:0A:C4:E6:0E:9C Channel: 0 Link: down
[..]
```
When lwIP is hacked to use the same shell command, it also
lists it interfaces in the expected order (was ET1,ET0 before):
```
> ifconfig
Iface ET0 HWaddr: 24:0A:C4:E6:0E:9F Link: down
[..]
Iface ET1 HWaddr: 24:0A:C4:E6:0E:9C Channel: 0 Link: down
[..]
```
Module to lock the shell after a given timeout of time x. When the
shell did not receive any input within time x, then the shell is
locked automatically.
Module to lock the running shell with a password. Shell is proceeded only
when the valid password was entered by the user. After 3 failed attempts,
the input is blocked for a few seconds to slow down brute force attacks.
Does not make use of any cryptographic features yet.
This solves highly theoretical race conditions of file systems being
unmounted in an application while a shell `df` runs, fixes the previous
weird behavior that `/mountpoint/non-existant-path` could be df'd and
would even report that non-existant path as a file name, but more
practically ensures that an example of vfs_iter_mount_dirs is around.
