The difference in the handlers was that in the
NETDEV_EVENT_DISCONNECT_BY_AP case we would make sure to reply
to a pending dbus Connect call. We also need to do that for
NETDEV_EVENT_DISCONNECT_BY_SME. This happens if another process
sends an nl80211 disconnect command while we're connecting.
Until now we'd save the second 32 bytes of the MSK as the PMK and use
that for the PMK-R0 as well as the PMKID calculation. The PMKID
actually uses the first 32 bytes of the PMK while the PMK-R0's XXKey
input maps to the second 32 bytes. Add a pmk_len parameter to
handshake_state_set_pmk to handle that. Update the eapol_eap_results_cb
802.11 quotes to the 2016 version.
Some APs respond to Neighbor Report Requests with neighbor reports that
have a zero operating class value and a non-zero channel number. This
does not mean that the channel is in the same band that the reporting
AP operates in. Try to guess the band that the channel refers to out of
2.4 and 5GHz -- the bands supported by those APs.
wpa_supplicant also has this workaround in place.
When we call scan_periodic_stop and a periodic scan is in progress (i.e.
the trigger callback has been called already) we get no new callback
from scan.c and the device Scanning property remains True forever so set
it to False.
The change from scan_periodic_stop to periodic_scan_stop looks silly but
it's consistent with our naming :)
This patch adds a watcher/parser for the frame event associated with
an AP directed BSS transition (AP roaming). When the AP sends a BSS
transition request, this will parse out the BSS candidate list
(neighbor report) and initiate a roam scan. After this point the
existing roaming code path is reused.
Make sure device->autoconnect is set when entering the autoconnect state
after netdev UP event. Otherwise the next time
device_set_autoconnect(device, false) is called it will exit early seeing
that device->autoconnect is false and not switch the device state.
As a temporary DBus API to switch between Station and Access Point
modes, add two methods on the Device interface. Add a new state
DEVICE_STATE_ACCESS_POINT which is in effect from the moment
StartAccessPoint is received (even before it returns) until
StopAccessPoint returns, there are no intermediate states when the
methods run for simplicity. Add checks across device.c to make sure
Station related functionality is disabled when in Access Point mode.
Modify netdev_get_iftype, which was until now unused, and add
netdev_set_iftype. Don't skip interfaces with types other than STATION
on startup, instead reset the type to STATION in device.c.
netdev_get_iftype is modified to use our own interface type enum to
avoid forcing users to include "nl80211.h".
Note that setting an interface UP and DOWN wouldn't generally reset the
iftype to STATION. Another process may still change the type while iwd
is running and iwd would not detect this as it would detect another
interface setting interface DOWN, not sure how far we want to go in
monitoring all of the properties this way.
If we're adding the BSS to the list only because it is the current BSS,
set the rank to 0 (lowest possible value) in case the list gets used in
the next Connect call.
Allow attempts to connect to a new AP using the Reassociation frame even
if netdev->operational is false. This is needed if we want to continue
an ongoing roam attempt after the original connection broke and will be
needed when we start using cached PMKSAs in the future.
Use beacon loss event to trigger a roam attempt in addition to the RSSI
monitoring. Due to the how well beacons are normally received compared
to data packets, a beacon loss indicates a serious problem with the
connection so act as soon as a first beacon loss event is seen.
Avoid roaming methods that involve the current AP: preauthentication,
neighbor report request and FT-over-the-DS (not supported)
The kernel doesn't reset the netdev's state to disconnected when it
sends us a beacon loss event so we can't either unless we automatically
send a disconnect command to the kernel.
It seems the handling of beacon loss depends on the driver. For example
in mac80211 only after N beacon loss events (default 7) a probe request is
sent to the AP and a deauthenticate packet is sent if no probe reply is
receiver within T (default 500ms).
Allow registering and unregistering agent object to receive RSSI level
notifications. The methods are similar to the ones related to the
password agent, including a Release method for the agent.
Add an methods and an event using the new
NL80211_EXT_FEATURE_CQM_RSSI_LIST kernel feature to request RSSI
monitoring with notifications only when RSSI moves from one of the N
intervals requested to another.
device.c will call netdev_set_rssi_report_levels to request
NETDEV_EVENT_RSSI_LEVEL_NOTIFY events every time the RSSI level changes,
level meaning one of the intervals delimited by the threshold values
passed as argument. Inside the event handler it can call
netdev_get_rssi_level to read the new level.
There's no fallback to periodic polling implemented in this patch for
the case of older kernels and/or the driver not supporting
NL80211_EXT_FEATURE_CQM_RSSI_LIST.
Use netdev_reassociate if FT is not available. device_select_akm_suite
is only moved up in the file and the reused code from device_connect is
moved to a separate function.
Pass an additional parameter to the scan results notify functions to
tell them whether the scan was successful. If it wasn't don't bother
passing an empty bss_list queue, pass NULL as bss_list. This way the
callbacks can tell whether the scan indicates there are no BSSes in
range or simply was aborted and the old scan results should be kept.
++++++++ backtrace ++++++++
0 0x7fc0b20ca370 in /lib64/libc.so.6
1 0x4497d5 in l_dbus_message_new_error_valist() at /home/denkenz/iwd/ell/dbus-message.c:372
2 0x44994d in l_dbus_message_new_error() at /home/denkenz/iwd/ell/dbus-message.c:394
3 0x41369b in dbus_error_not_supported() at /home/denkenz/iwd/src/dbus.c:148
4 0x40eaf5 in device_connect_network() at /home/denkenz/iwd/src/device.c:1282
5 0x41f61c in network_autoconnect() at /home/denkenz/iwd/src/network.c:424
6 0x40c1c1 in device_autoconnect_next() at /home/denkenz/iwd/src/device.c:172
7 0x40cabf in device_set_scan_results() at /home/denkenz/iwd/src/device.c:368
8 0x40cb06 in new_scan_results() at /home/denkenz/iwd/src/device.c:376
9 0x41be8a in scan_finished() at /home/denkenz/iwd/src/scan.c:1021
10 0x41bf9e in get_scan_done() at /home/denkenz/iwd/src/scan.c:1048
11 0x43d5ce in destroy_request() at /home/denkenz/iwd/ell/genl.c:136
12 0x43ded1 in process_unicast() at /home/denkenz/iwd/ell/genl.c:395
13 0x43e295 in received_data() at /home/denkenz/iwd/ell/genl.c:502
14 0x43aa62 in io_callback() at /home/denkenz/iwd/ell/io.c:120
15 0x439632 in l_main_run() at /home/denkenz/iwd/ell/main.c:375 (discriminator 2)
16 0x403074 in main() at /home/denkenz/iwd/src/main.c:261
17 0x7fc0b20b7620 in /lib64/libc.so.6
Handle the changes of interface address in RTNL New Link messages
similarly to the name changes, emit a NETDEV_WATCH_EVENT_ADDRESS_CHANGE
event and a propety change on dbus.
Note this can only happen when the interface is down so it doesn't
break anything but we need to handle it anyway.
Define minimum delay between roam attempts and add automatic retries.
This handles a few situations:
* roam attempt failing, then RSSI going above the threshold and below
again -- in that case we don't want to reattempt too soon, we'll only
reattempt after 60s.
* roam attempt failing then RSSI staying low for longer than 60 -- in
that case we want to reattempt after 60s too.
* signal being low from the moment we connected -- in that case we also
want to attempt a roam every some time.
Fix a leak of the MDE buffer. It is now only needed for the single call
to handshake_state_set_mde which copies the bytes anyway so use a buffer
on stack.
Add a flush flag to scan_parameters to tell the kernel to flush the
cache of scan results before the new scan. Use this flag in the
active scan during roaming.
Make sure that the Neighbor Report timeout is cancelled when connection
breaks or device is being destroyed, and call the callback. Add an
errno parameter to the callback to indicate the cause.
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.
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.
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.
Remove the keys and other data from struct eapol_sm, update device.c,
netdev.c and wsc.c to use the handshake_state object instead of
eapol_sm. This also gets rid of eapol_cancel and the ifindex parameter
in some of the eapol functions where sm->handshake->ifindex can be
used instead.
If device_select_akm_suite selects Fast Transition association then pass
the MD IE and other bits needed for eapol and netdev to do an FT
association and 4-Way Handshake.
If an MD IE is supplied to netdev_connect, pass that MD IE in the
associate request, then validate and handle the MD IE and FT IE in the
associate response from AP.
Don't decide on the AKM suite to use when the bss entries are received
and processed, instead select the suite when the connection is triggered
using a new function device_select_akm_suite, similar to
wiphy_select_cipher(). Describing the AKM suite through flags will be
more difficult when more than 2 suites per security type are supported.
Also handle the wiphy_select_cipher 0 return value when no cipher can be
selected.
Andrew Zaborowski