This is being added as a developer method and should not be used
in production. For testing purposes though, it is quite useful as
it forces IWD to roam to a provided BSS and bypasses IWD's roaming
and ranking logic for choosing a roam candidate.
To use this a BSSID is provided as the only parameter. If this
BSS is not in IWD's current scan results -EINVAL will be returned.
If IWD knows about the BSS it will attempt to roam to it whether
that is via FT, FT-over-DS, or Reassociation. These details are
still sorted out in IWDs station_transition_start() logic.
FT-over-DS was refactored to separate the FT action frame and
reassociation. From stations standpoint IWD needs to call
netdev_fast_transition_over_ds_action prior to actually roaming.
For now these two stages are being combined and the action
roam happens immediately after the action response callback.
Prior to this the diagnostic interface was taken down when station
transitioned to DISCONNECTED. This worked but once station is in
a DISCONNECTING state it then calls netdev_disconnect(). Trying to
get any diagnostic data during this time may not work as its
unknown what state exactly the kernel is in. To be safe take the
interface down when station is DISCONNECTING.
Under very rare circumstances the roaming scan triggered might not be
canceled properly. This is because we issue the roam scan recursively
from within a scan callback and re-use the id of the scan for the
subsequent request. The destroy callback is invoked right after the
callback and resets the id. This leads to the scan not being canceled
properly in roam_state_clear().
src/netdev.c:netdev_mlme_notify() MLME notification Notify CQM(64)
src/station.c:station_roam_trigger_cb() 37
src/station.c:station_roam_scan() ifindex: 37
src/station.c:station_roam_trigger_cb() Using cached neighbor report for roam
...
src/scan.c:get_scan_done() get_scan_done
src/station.c:station_roam_failed() 37
src/station.c:station_roam_scan() ifindex: 37
src/scan.c:scan_request_triggered() Active scan triggered for wdev 22
^CTerminate
src/netdev.c:netdev_free() Freeing netdev wlan0[37]
src/device.c:device_free()
src/station.c:station_free()
...
Removing scan context for wdev 22
src/scan.c:scan_context_free() sc: 0x4a362a0
src/wiphy.c:wiphy_radio_work_done() Work item 14 done
==19542== Invalid write of size 4
==19542== at 0x411500: station_roam_scan_destroy (station.c:2010)
==19542== by 0x420B5B: scan_request_free (scan.c:156)
==19542== by 0x410BAC: destroy_work (wiphy.c:294)
==19542== by 0x410BAC: wiphy_radio_work_done (wiphy.c:1613)
==19542== by 0x46C66E: l_queue_clear (queue.c:107)
==19542== by 0x46C6B8: l_queue_destroy (queue.c:82)
==19542== by 0x420BAE: scan_context_free (scan.c:205)
==19542== by 0x424135: scan_wdev_remove (scan.c:2272)
==19542== by 0x408754: netdev_free (netdev.c:847)
==19542== by 0x40E18C: netdev_shutdown (netdev.c:5773)
==19542== by 0x404756: iwd_shutdown (main.c:78)
==19542== by 0x404756: iwd_shutdown (main.c:65)
==19542== by 0x470E21: handle_callback (signal.c:78)
==19542== by 0x470E21: signalfd_read_cb (signal.c:104)
==19542== by 0x47166B: io_callback (io.c:120)
==19542== Address 0x4d81f98 is 200 bytes inside a block of size 288 free'd
==19542== at 0x48399CB: free (vg_replace_malloc.c:538)
==19542== by 0x47F3E5: interface_instance_free (dbus-service.c:510)
==19542== by 0x481DEA: _dbus_object_tree_remove_interface (dbus-service.c:1694)
==19542== by 0x481F1C: _dbus_object_tree_object_destroy (dbus-service.c:795)
==19542== by 0x40894F: netdev_free (netdev.c:844)
==19542== by 0x40E18C: netdev_shutdown (netdev.c:5773)
==19542== by 0x404756: iwd_shutdown (main.c:78)
==19542== by 0x404756: iwd_shutdown (main.c:65)
==19542== by 0x470E21: handle_callback (signal.c:78)
==19542== by 0x470E21: signalfd_read_cb (signal.c:104)
==19542== by 0x47166B: io_callback (io.c:120)
==19542== by 0x47088C: l_main_iterate (main.c:478)
==19542== by 0x47095B: l_main_run (main.c:525)
==19542== by 0x47095B: l_main_run (main.c:507)
==19542== by 0x470B6B: l_main_run_with_signal (main.c:647)
==19542== Block was alloc'd at
==19542== at 0x483879F: malloc (vg_replace_malloc.c:307)
==19542== by 0x46AB2D: l_malloc (util.c:62)
==19542== by 0x416599: station_create (station.c:3448)
==19542== by 0x406D55: netdev_newlink_notify (netdev.c:5324)
==19542== by 0x46D4BC: l_hashmap_foreach (hashmap.c:612)
==19542== by 0x472F46: process_broadcast (netlink.c:158)
==19542== by 0x472F46: can_read_data (netlink.c:279)
==19542== by 0x47166B: io_callback (io.c:120)
==19542== by 0x47088C: l_main_iterate (main.c:478)
==19542== by 0x47095B: l_main_run (main.c:525)
==19542== by 0x47095B: l_main_run (main.c:507)
==19542== by 0x470B6B: l_main_run_with_signal (main.c:647)
==19542== by 0x403EDB: main (main.c:490)
==19542==
A prior commit refactored the AKM selection in wiphy.c. This
ended up breaking FILS tests due to the hard coding of a
false fils_hint in wiphy_select_akm. Since our FILS tests
only advertise FILS AKMs wiphy_can_connect would return false
for these networks.
Similar to wiphy_select_akm, add a fils hint parameter to
wiphy_can_connect and pass that down directly to wiphy_select_akm.
Logically this frame watch belongs in station. It was kept in device.c
for the purported reason that the station object was removed with
ifdown/ifup changes and hence the frame watch might need to be removed
and re-added unnecessarily. Since the kernel does not actually allow to
unregister a frame watch (only when the netdev is removed or its iftype
changes), re-adding a frame watch might trigger a -EALREADY or similar
error.
Avoid this by registering the frame watch when a new netdev is detected
in STATION mode, or when the interface type changes to STATION.
station should be isolated as much as possible from the details of the
driver type and how a particular AKM is handled under the hood. It will
be up to wiphy to pick the best AKM for a given bss. netdev in turn
will pick how to drive the particular AKM that was picked.
In the same vein as requesting a neighbor report after
connecting for the first time, it should also be done
after a roam to obtain the latest neighbor information.
When we cancel a quick scan that has already been triggered, the
Scanning property is never reset to false. This doesn't fully reflect
the actual scanning state of the hardware since we don't (yet) abort
the scan, but at least corrects the public API behavior.
{Network} [/net/connman/iwd/0/7/73706733_psk] Connected = False
{Station} [/net/connman/iwd/0/7] Scanning = True
{Station} [/net/connman/iwd/0/7] State = connecting
{Station} [/net/connman/iwd/0/7] ConnectedNetwork =
/net/connman/iwd/0/7/73706733_psk
{Network} [/net/connman/iwd/0/7/73706733_psk] Connected = True
If IWD is connecting to a SAE/WPA3 BSS and Auth/Assoc commands
are not supported the only option is SAE offload. At this point
network_connect should have verified that the extended feature
for SAE offload exists so we can simply enable offload if these
commands are not supported.
If the hardware roams automatically we want to be sure to not
react to CQM events and attempt to roam/disconnect on our own.
Note: this is only important for very new kernels where CQM
events were recently added to brcmfmac.
Roaming on a full mac card is quite different than soft mac
and needs to be specially handled. The process starts with
the CMD_ROAM event, which tells us the driver is already
roamed and associated with a new AP. After this it expects
the 4-way handshake to be initiated. This in itself is quite
simple, the complexity comes with how this is piped into IWD.
After CMD_ROAM fires its assumed that a scan result is
available in the kernel, which is obtained using a newly
added scan API scan_get_firmware_scan. The only special
bit of this is that it does not 'schedule' a scan but simply
calls GET_SCAN. This is treated special and will not be
queued behind any other pending scan requests. This lets us
reuse some parsing code paths in scan and initialize a
scan_bss object which ultimately gets handed to station so
it can update connected_bss/bss_list.
For consistency station must also transition to a roaming state.
Since this roam is all handled by netdev two new events were
added, NETDEV_EVENT_ROAMING and NETDEV_EVENT_ROAMED. Both allow
station to transition between roaming/connected states, and ROAMED
provides station with the new scan_bss to replace connected_bss.
An earlier patch fixed a problem where a queued quick scan would
be triggered and fail once already connected, resulting in a state
transition from connected --> autoconnect_full. This fixed the
Connect() path but this could also happen via autoconnect. Starting
from a connected state, the sequence goes:
- DBus scan is triggered
- AP disconnects IWD
- State transition from disconnected --> autoconnect_quick
- Queue quick scan
- DBus scan results come in and used to autoconnect
- A connect work item is inserted ahead of all others, transition
from autoconnect_quick --> connecting.
- Connect completes, transition from connecting --> connected
- Quick scan can finally get triggered, which the kernel fails to
do since IWD is connected, transition from connected -->
autoconnect_full.
This can be fixed by checking for a pending quick scan in the
autoconnect path.
Commit eac2410c83 ("station: Take scanned frequencies into account")
has made it unnecessary to explicitly invoke station_set_scan_results
with the expire to true in case a dbus scan finished prematurely or a
subset was not able to be started. Remove this no-longer needed logic.
Fixes: eac2410c83 ("station: Take scanned frequencies into account")
The diagnostic interface returns an error anyways if station is
not connected so it makes more sense to only bring the interface
up when its actually usable. This also removes the interface
when station disconnects, which was never done before (the
interface stayed up indefinitely due to a forgotten remove call).
When we're auto-connecting and have hidden networks configured, use
active scans regardless of whether we see any hidden BSSes in our
existing scan results.
This allows us to more effectively see/connect to hidden networks
when first powering up or after suspend.
Kernel might report hidden BSSes that are reported from beacon frames
separately than ones reported due to probe responses. This may confuse
the station network collation logic since the scan_bss generated by the
probe response might be removed erroneously when processing the scan_bss
that was generated due to a beacon.
Make sure that bss_match also takes the SSID into account and only
matches scan_bss structures that have the same BSSID and SSID contents.
Instead of manually managing whether to expire BSSes or not, use the
scanned frequency set instead. This makes the API slightly easier to
understand (dropping two boolean arguments in a row) and also a bit more
future-proof.
Commit d372d59bea checks whether a hidden network had a previous
connection attempt and re-tries. However, it inadvertently dropped
handling of a condition where a non-hidden network SSID is provided to
ConnectHiddenNetwork. Fix that.
Fixes: d372d59bea ("station: Allow ConnectHiddenNetwork to be retried")
Now that ConnectHiddenNetwork can be invoked while we're connected, set
the mac randomization hint parameter properly. The kernel will reject
requests if randomization is enabled while we're connected to a network.
If we forget a hidden network, then make sure to remove it from the
network list completely. Otherwise it would be possible to still
issue a Network.Connect to that particular object, but the fact that the
network is hidden would be lost.
==17639== 72 (16 direct, 56 indirect) bytes in 1 blocks are definitely
lost in loss record 3 of 3
==17639== at 0x4C2F0CF: malloc (vg_replace_malloc.c:299)
==17639== by 0x4670AD: l_malloc (util.c:61)
==17639== by 0x4215AA: scan_freq_set_new (scan.c:1906)
==17639== by 0x412A9C: parse_neighbor_report (station.c:1910)
==17639== by 0x407335: netdev_neighbor_report_frame_event
(netdev.c:3522)
==17639== by 0x44BBE6: frame_watch_unicast_notify (frame-xchg.c:233)
==17639== by 0x470C04: dispatch_unicast_watches (genl.c:961)
==17639== by 0x470C04: process_unicast (genl.c:980)
==17639== by 0x470C04: received_data (genl.c:1101)
==17639== by 0x46D9DB: io_callback (io.c:118)
==17639== by 0x46CC0C: l_main_iterate (main.c:477)
==17639== by 0x46CCDB: l_main_run (main.c:524)
==17639== by 0x46CF01: l_main_run_with_signal (main.c:656)
==17639== by 0x403EDE: main (main.c:490)
In the case that ConnectHiddenNetwork scans successfully, but fails for
some other reason, the network object is left in the scan results until
it expires. This will prevent subsequent attempts to use
ConnectHiddenNetwork with a .NotHidden error. Fix that by checking
whether a found network is hidden, and if so, allow the request to
proceed.
Rework the logic slightly so that this function returns an error message
on error and NULL on success, just like other D-Bus method
implementations. This also simplifies the code slightly.
We used to not allow to connect to a different network while already
connected. One had to disconnect first. This also applied to
ConnectHiddenNetwork calls.
This restriction can be dropped now. station will intelligently
disconnect from the current AP when a station_connect_network() is
issued.
If the disconnect fails and station_disconnect_onconnect_cb is called
with an error, we reply to the original message accordingly.
Unfortunately pending_connect is not unrefed or cleared in this case.
Fix that.
Fixes: d0ee923dda ("station: Disconnect, if needed, on a new connection attempt")
At some point the non-interactive client tests began failing.
This was due to a bug in station where it would transition from
'connected' to 'autoconnect' due to a failed scan request. This
happened because a quick scan got scheduled during an ongoing
scan, then a Connect() gets issued. The work queue treats the
Connect as a priority so it delays the quick scan until after the
connection succeeds. This results in a failed quick scan which
IWD does not expect to happen when in a 'connected' state. This
failed scan actually triggers a state transition which then
gets IWD into a strange state where its connected from the
kernel point of view but does not think it is:
src/station.c:station_connect_cb() 13, result: 0
src/station.c:station_enter_state() Old State: connecting, new state: connected
src/wiphy.c:wiphy_radio_work_done() Work item 6 done
src/wiphy.c:wiphy_radio_work_next() Starting work item 5
src/station.c:station_quick_scan_triggered() Quick scan trigger failed: -95
src/station.c:station_enter_state() Old State: connected, new state: autoconnect_full
To fix this IWD should simply cancel any pending quick scans
if/when a Connect() call comes in.
With AP now getting its own diagnostic interface it made sense
to move the netdev_station_info struct definition into its own
header which eventually can be accompanied by utilities in
diagnostic.c. These utilities can then be shared with AP and
station as needed.
Following a successful roaming sequence, schedule another attempt unless
the driver has sent a high RSSI notification. This makes the behaviour
analogous to a failed roaming attempt where we remained connected to the
same BSS.
This makes iwd compatible with wireless drivers which do not necessarily
send out a duplicate low RSSI notification upon reassociation. Without
this change, iwd risks getting indefinitely stuck to a BSS with low
signal strength, even though a better BSS might later become available.
In the case of a high RSSI notification, the minimum roam time will also
be reset to zero. This preserves the original behaviour in the case
where a high RSSI notification is processed after station_roamed().
Doing so also gives a chance for faster roaming action in the following
example scenario:
1. RSSI LOW
2. schedule roam in 5 seconds
(5 seconds pass)
3. try roaming
4. roaming fails, same BSS
5. schedule roam in 60 seconds
(20 seconds pass)
6. RSSI HIGH
7. cancel scheduled roam
(20 seconds pass)
8. RSSI LOW
9. schedule roam in 5 seconds or 20 seconds?
By resetting the minimum roam time, we can avoid waiting 20 seconds when
the station may have moved considerably. And since the high/low RSSI
notifications are configured with a hysteresis, we should still be
protected against too frequent spurious roaming attempts.
Add a parameter to station_set_scan_results to allow skipping the
removal of old BSSes. In the DBus-triggered scan only expire BSSes
after having gone through the full supported frequency set.
It should be safe to pass partial scan results to
station_set_scan_results() when not expiring BSSes so using this new
parameter I guess we could also call it for roam scan results.
A scan normally takes about 2 seconds on my dual-band wifi adapter when
connected. The drivers will normally probe on each supported channel in
some unspecified order and will have new partial results after each step
but the kernel sends NL80211_CMD_NEW_SCAN_RESULTS only when the full
scan request finishes, and for segmented scans we will wait for all
segments to finish before calling back from scan_active() or
scan_passive().
To improve user experience define our own channel order favouring the
2.4 channels 1, 6 and 11 and probe those as an individual scan request
so we can update most our DBus org.connman.iwd.Network objects more
quickly, before continuing with 5GHz band channels, updating DBus
objects again and finally the other 2.4GHz band channels.
The overall DBus-triggered scan on my wifi adapter takes about the same
time but my measurements were not very strict, and were not very
consistent with and without this change. With the change most Network
objects are updated after about 200ms though, meaning that I get most
of the network updates in the nm-applet UI 200ms from opening the
network list. The 5GHz band channels take another 1 to 1.5s to scan and
remaining 2.4GHz band channels another ~300ms.
Hopefully this is similar when using other drivers although I can easily
imagine a driver that parallelizes 2.4GHz and 5GHz channel probing using
two radios, or uses 2, 4 or another number of dual-band radios to probe
2, 4, ... channels simultanously. We'd then lose some of the
performance benefit. The faster scan results may be worth the longer
overall scan time anyway.
I'm also assuming that the wiphy's supported frequency list is exactly
what was scanned when we passed no frequency list to
NL80211_CMD_TRIGGER_SCAN and we won't get errors for passing some
frequency that shouldn't have been scanned.
