The testAPRoam autotest was silently failing on my machine until I
realized that my distribution hostapd (Arch Linux) is not built with
CONFIG_WNM_AP=y. Indeed, it is also disabled by default in upstream
hostapd. This resulted in the send_bss_transition() function of
hostapd.py silently failing. With this change, throw an exception in
case the BSS_TM_REQ command does not succeed to hopefully save others
the time of debugging this problem.
There were some major problems related to logging and process
output. Tests which required output from start_process would
break if used with '--log/--verbose'. This is because we relied
on 'communicate' to retrieve the process output, but Popen does
not store process output when stdout/stderr are anything other
than PIPE.
Intead, in the case of logging or outfiles, we can simply read
from the file we just wrote to.
For an explicit --verbose application we must handle things
slightly different. A keyword argument was added to Process,
'need_out' which will ensure the process output is kept
regardless of --log or --verbose.
Now a user should be able to use --log/--verbose without any
tests failing.
After the re-write this was broken and not noticed until
recently. The issue appeared to be that the GLib timeout
callback retained no context of local variables. Previously
_wait_timed_out was set as a class variable, but this was
removed so multiple IWD instances could work. Without
_wait_timed_out being a class variable the GLib timeout
setting it had no effect on the wait loop.
To fix this we can set _wait_timed_out on the object being
passed in. This is preserved in the GLib timeout callback
and setting it gets honored in the wait loop.
Certain classes were still using the default namespace. This
didn't matter yet since testAP was the only test using namespaces,
and the AP interface was the only one being used.
For an IWD station on a separate namespace all objects need to
be accessable, so the namespace is passed along to those as needed.
When network namespaces are introduced there may be multiple
IWD class instances. This makes IWD.get_instance ambiguous
when namespaces are involved. iwd.py has been refactored to
not use IWD.get_instance, but testutil still needs it since
its purely based off interface names. Rather than remove it
and modify every test to pass the IWD object we can just
maintain the existing behavior for only the root namespace.
The agent path was generated based on the current time which
sometimes yielded duplicate paths if agents were created quickly
after one another. Instead a simple iterator removes any chance
of a duplicate path.
If the caller specifies the number of devices only return that many.
Some sub-tests may only need a subset of the total number of devices
for the test. If the number of devices expected is less than the total
being returned, python would throw an exception.
If a test does not need any hostapd instances but still loads
hostapd.py for some reason we want to gracefully throw an
exception rather than fail in some other manor.
Add the new wpas.Wpas class roughly based on hostapd.HostapdCLI but only
adding methods for the P2P-related stuff.
Adding "wpa_supplicant" to -v will enable output from the wpa_supplicant
process to be printed and "wpa_supplicant-dbg" will make it more verbose
("wpa_supplicant" is not needed because it seems to be automatically
enabled because of the glob matching in ctx.is_verbose)
The host systems configuration directories for IWD/EAD were
being mounted in the virtual machine. This required that the
host create these directories before hand. Instead we can
just set up the system and IWD/EAD to use directories in /tmp
that we create when we start the VM. This avoids the need for
any host configuration.
This module is essentially a heavily stripped down version of iwd.py
to work with EAD. Class names were changed to match EAD but basically
the EAD, Adapter, and AdapterList classes map 1:1 to IWD, Device, and
DeviceList.
This is somewhat of a hack, but the IWDDBusAbstract is a very
convenient abstraction to DBus objects. The only piece that restricts
it to IWD is the hardcoded IWD_SERVICE. Instead we can pass in a
keyword argument which defaults to IWD_SERVICE. That way other modules
(like EAD) can utilize this abstraction with their own service simply
by changing that service argument.
The AdHoc functionality in iwd.py was not consistent at all with
how all the other classes worked (my bad). Instead we can create
a very simple AdHocDevice class which inherits all the DBus magic
in the IWDDBusAbstract class.
This got added in the re-write but a __del__ method was also
added to the Rule class as well. This caused problems if hwsim
cleaned up since it removed the rules, which caused each rule
to call __del__. Since the rule had already been removed there
was no longer a DBus interface which raised an exception.
Before the re-write there was interesting escapes being used for
set_neighbor. Curiously now hostapd fails to set the neighbor due
to these escapes so they have been removed.
Slower systems may not be able to make some timeouts that tests
mandated. All timeouts were increased significantly to allow tests
to pass on slow systems.
It is not safe to assume that the python dbus implementation will
wait for a method to return. The documentation says this with
respect to reply_handler/error_handler:
"If both are None, the implementation may request that no reply is sent"
To stay on the safe side we should always include the error/reply
handlers and wait for the operation to complete.
iwd.py was updated to use the TestContext APIs to start/stop
IWD. This makes the process managment consistent between starting
IWD from test-runner or from the IWD() constructor.
The psk agent is now tracked, and destroyed upon __del__. This is
to fix issues where a test throws an exception and never
unregisters the agent, causing future tests to fail.
The configuration directory was also chaged to /tmp by
default. This was done since all tests which used this used /tmp
anyways.
The GLib mainloop was removed, and instead put into test-runner
itself. Now any mainloop operations can use ctx.mainloop instead
Before hostapd was initialized using the wiphy_map which has now
gone away. Instead we have a global config module which contains
a single 'ctx'. This is the centeral store for all test information.
This patch converts hostapd.py to lookup instances by already
initialized Hostapd object. The interface parameter was removed
since all tests have been converted to use config= instead.
In addition HostapdCLI was changed to allow no parameters if there
is only a single hostapd instance.
This patch completely re-writes test-runner in Python. This was done
because the existing C test-runner had some clunky work arounds and
maintaining or adding new features was starting to become a huge pain.
There were a few aspects of test-runner which continually had to
be dealt with when adding any new functionality:
* Argument parsing: Adding new arguments to test-runner wasn't so
bad, but if you wanted those arguments passed into the VM it
became a huge pain. Arguments needed to be parsed, then re-formatted
into the qemu command line, then re-parsed in a special order
(backwards) once in the VM. The burden for adding new arguments was
quite high so it was avoided (at least by me) at all costs.
* The separation between C and Python: The tests are all written in
python, but the executables, radios, and interfaces were all created
from C. The way we solved this was by encoding the require info as
environment variables, then parsing those from Python. It worked,
but it was, again, a huge pain.
* Process management: It started with all processes being launched
from C, but eventually tests required the ability to start IWD, or
kill hostapd ungracefully in order to test certain functionality.
Since the processes were tracked in C, Python had no way of
signalling that it killed a process and when it started one C had
no idea. This was mitigated (basically by killall), but it was
no where close to an elegant solution.
Re-writing test-runner in python solves all these problems and will
be much easier to maintain.
* Argument parsing: Now all arguments are forwarded automatically
to the VM. The ArgParse library takes care of parsing and each
argument is stored in a dictionary.
* Separation between C and Python: No more C, so no more separation.
* Process management: Python will now manage all processes. This
allows a test to kill, restart, or start a new process and not
have to remember the PID or to kill it after the test.
There are a few more important aspects of the python implementation
that should now be considered when writing new tests:
* The IWD constructor now has different default arugments. IWD
will always be started unless specified and the configuration
directory will always be /tmp
* Any non *.py file in the test directory will be copied to /tmp.
This avoids the need for 'tmpfs_extra_stuff' completely.
* ctrl_interface will automatically be appended to every hostapd
config. There is no need to include this in a config file from
now on.
* Test cleanup is extremely important. All tests get run in the
same interpreter now and the tests themselves are actually loaded
as python modules. This means e.g. if you somehow kept a reference
to IWD() any subsequent tests would not start since IWD is still
running.
* For debugging, the test context can be printed which shows running
processes, radios, and interfaces.
Three non-native python modules were used: PrettyTable, colored, and
pyroute2
$ pip3 install prettytable
$ pip3 install termcolor
$ pip3 install pyroute2
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.
There is a very common block of code inside many autotests
which goes something like:
device.scan()
condition = 'obj.scanning'
wd.wait_for_object_condition(device, condition)
condition = 'not obj.scanning'
wd.wait_for_object_condition(device, condition)
network = device.get_ordered_network('an-ssid')
When you see the same pattern in nearly all the tests this shows
we need a helper. Basic autotests which merely check that a
connection succeeded should not need to write the same code again
and again. This code ends up being copy-pasted which can lead to
bugs.
There is also a code pattern which attempts to get ordered
networks, and if this fails it scans and tries again. This, while
not optimal, does prevent unneeded scanning by first checking if
any networks already exist.
This patch solves both the code reuse issue as well as the recovery
if get_ordered_network(s) fails. A new optional parameter was
added to get_ordered_network(s) which is False by default. If True
get_ordered_network(s) will perform a scan if the initial call
yields no networks. Tests will now be able to simply call
get_ordered_network(s) without performing a scan before hand.
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 no networks are found, return None rather than an empty
array. This is easier to check by the caller (and was assumed
in some cases). Also add an exception to get_ordered_network
if no network is found.
