Restarting hostapd from python was actually leaking memory and
causing the hostapd object to stay referenced in python. The
GLib timeout in wait_for_event was the ultimate cause, but this
had no come to light because no tests restarted hostapd then
used wait_for_event.
In addition, any use of wait_for_event after a restart would
cause an exception because the event socket was never re-attached
after hostapd restarted.
Now we properly clean up the timeout in wait_for_event and
re-initialize the hostapd object on restart.
Hostapd has a feature where you can connect to its control socket and
receive events it generates. Currently we only send commands via this
socket.
First we open the socket (/var/run/hostapd/<iface>) and send the
ATTACH command. This tells hostapd we are ready and after this any
events will be sent over this socket.
A new API, wait_for_event, was added which takes an event string and
waits for some timeout. The glib event loop has been integrated into
this, though its not technically async since we are selecting over a
socket which blocks. To mitigate this a small timeout was chosen for
each select call and then wrapped in a while loop which waits for the
full timeout.
If the config file passed in is not found we would continue and
eventually something else would fail. Instead immediately raise an
exception to be more clear on what is actually failing.
There is a common interface lookup in many tests in order to initialize
the HostapdCLI object e.g.:
for intf in hostapd_map.values():
if intf.config == 'ssidOWE.conf':
hapd = HostapdCLI(intf)
break
Instead of having to do this in every test, HostapdCLI will now
optionally take a config file (config=<file>). The interface object
will still be prefered (i.e. supplying an interface will not even
check the config file) as to not break existing tests. But if only
a config file is supplied the lookup is done internally.
There are some tests that do still need the interface, as they do
an interface lookup to initialize both hostapd and hwsim at the
same time.
The hostapd_map dictionary is indexed by the interface name so there's
no point iterating over it to find that entry whose name matches, we can
look up by the name directly. Simplify code.
In the test utilties updated the wiphy_map struct built from the
TEST_WIPHY_LIST variable to parse the new format and to use a new
structure where each wiphy is a namedtuple and each interface under it
also contains a reference to that wiphy. The 'use' field is now
assigned to the wiphy instead of to the interface.
At some point a stray ';' got added into an autotest in a section
of code that is heavily copy pasted. So in turn nearly all the autotests
have this stray ';' after list_devices (and a few in other places).
The hwsim SendFrame method requires the radio frequency which
is obtained from the hostapd config file. This adds a generic
API to get any config value from the hostapd config, as well
as a get_freq API that converts the channel number to a
frequency.
For testing SA Query, the autotest needs the ablility to force
kill (and restart) hostapd without giving it time to deauth its
stations gracefully. A method was added to the HostapdCLI class
which does a killall -9 hostapd, resets the wlnX interface,
and restarts hostapd with the same arguments as it had before.
Make the HostapdCLI class non-static so that each objects corresponds
to a hostapd instance on one network interface (this is independent of
whether the AP instances use one or separate hostapd processes)
