With this patch an actual fast transition should happen when the signal
strength goes low but there are still various details to be fixed before
this becomes useful:
* the kernel tends to return cached scan results and won't update the
rssi values,
* there's no timer to prevent too frequent transition attempts or to
retry after some time if the signal is still low,
* no candidate other than the top ranked BSS is tried. With FT it
may be impossible to try another BSS anyway although there isn't
anything in the spec to imply this. It would require keeping the
handshake_state around after netdev gives up on the transition
attempt.
Trigger a scan of the selected channels or all channels if no useful
neighbor list was obtained, then process the scan results to select the
final target BSS.
The actual transition to the new BSS is not included in this patch for
readability.
Trigger a roam attempt when the RSSI level has been low for at least 5
seconds using the netdev RSSI LOW/HIGH events. See if neighbor reports
are supported and if so, request and process the neighbor reports list
to restrict the number of channels to be scanned. The scanning part is
not included in this patch for readability.
Validate the fourth message of the fast transition sequence and save the
new keys and state as current values in the netdev object. The
FT-specific IE validation that was already present in the initial MD
is moved to a new function.
Build and send the FT Authentication Request frame, the initial Fast
Transition message.
In this version the assumption is that once we start a transition attempt
there's no going back so the old handshake_state, scan_bss, etc. can be
replaced by the new objects immediately and there's no point at which both
the old and the new connection states are needed. Also the disconnect
event for the old connection is implicit. At netdev level the state
during a transition is almost the same with a new connection setup.
The first disconnect event on the netlink socket after the FT Authenticate
is assumed to be the one generated by the kernel for the old connection.
The disconnect event doesn't contain the AP bssid (unlike the
deauthenticate event preceding it), otherwise we could check to see if
the bssid is the one we are interested in or could check connect_cmd_id
assuming a disconnect doesn't happen before the connect command finishes.
This adds support for iwd.conf 'ManagementFrameProtection' setting.
This setting has the following semantics, with '1' being the default:
0 - MFP off, even if hardware is capable
1 - Use MFP if available
2 - MFP required. If the hardware is not capable, no connections will
be possible. Use at your own risk.
Despite RFC3748 mandating MSKs to be at least 256 bits some EAP methods
return shorter MSKs. Since we call handshake_failed when the MSK is too
short, EAP methods have to be careful with their calls to set_key_material
because it may result in a call to the method's .remove method.
EAP-TLS and EAP-TTLS can't handle that currently and would be difficult to
adapt because of the TLS internals but they always set msk_len to 64 so
handshake_failed will not be called.
Make sure that eap_set_key_material can free the whole EAP method and
EAP state machine before returning, by calling that function last. This
relies on eap_mschapv2_handle_success being the last call in about 5
stack frames above it too.
Action Frames are sent by nl80211 as unicast data. We're not receiving
any other unicast packets in iwd at this time so let netdev directly
handle all unicast data on the genl socket.
Add a version of scan_active that accepts a struct with the scan
parameters so we can more easily add new parameters. Since the genl
message is now built within scan_active_start the extra_ie memory
can be freed by the caller at any time.
killall doesn't wait for the iwd process to clean up, so using it is not
enough when cleaning up between tests.
Using killall -w also doesn't work since iwd is launched by the script.
By the time killall is invoked, the script process is also cleaned up.
So when iwd is killed via killall, nobody is there to reap the zombie
process (test-runner is running as init, but doesn't do this)
The easiest solution is to make the test script itself clean up any iwd
processes it launches. This is what has been implemented in the
previous patch.
clang complains about enum as var_arg type
because of the argument standard conversion.
In a small test I did neither clang nor gcc can
properly warn about out of range values, so it's
purely for documentation either way.
There are situations when a CMD_DISCONNECT or deauthenticate will be
issued locally because of an error detected locally where netdev would
not be able to emit a event to the device object. The CMD_DISCONNECT
handler can only send an event if the disconnect is triggered by the AP
because we don't have an enum value defined for other diconnects. We
have these values defined for the connect callback but those errors may
happen when the connect callback is already NULL because a connection
has been estabilshed. So add an event type for local errors.
These situations may occur in a transition negotiation or in an eapol
handshake failure during rekeying resulting in a call to
netdev_handshake_failed.
Some unit tests expect to be running from the top level iwd tree
directory to load certificates and such. Make sure that test-runner
chdirs to the appropriate directory prior to running the unit tests.
