This allows the MAC address of the interface to be changed when the
interface is set down even if the interface does not get completed
removed and re-added.
Signed-hostap: Jouni Malinen <j@w1.fi>
A disconnection event from the driver may end up getting delivered at a
time when wpa_supplicant is not even trying to connect (e.g., during a
scan that was already started after WPS provisioning step). In such a
case, there is not much point calling wpas_connection_failed() and
skipping this avoids confusing attempts of re-starting scanning while
the previous scan is still in progress.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
This cleans up the source code and makes it less likely that new AKM
addition misses some needed changes in the future.
Signed-hostap: Jouni Malinen <j@w1.fi>
The new event can be used when EAPOL TX status can't be reported as a
complete 802.11 frame but is instead reported as just the EAPOL data as
originally passed to hapd_send_eapol().
Signed-hostap: Johannes Berg <johannes.berg@intel.com>
The P2P_FIND command was failing if it was issued at the moment when
a scan operation was in progress. Avoid returning failure in this
case by scheduling the P2P find to start once the ongoing scan is
completed.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
wpa_supplicant_rsn_preauth_scan_results() needs to be called to
update RSN pre-authentication candidates. This cannot be done before
the wpa_supplicant_connect() call on the first association, but when
trying to figure out whether to roam, it is fine to do so for the
case when roaming is skipped.
Signed-hostap: Jouni Malinen <j@w1.fi>
The eloop timeout to stop TKIP countermeasures has to be canceled
on deinit path to avoid leaving bogus timeouts behind.
Signed-hostap: Jouni Malinen <j@w1.fi>
At least with driver_test.c, the BSS table may not include frequency
information. In such a case, we need to skip rate set matching during
BSS selection to avoid rejecting valid AP.
Signed-hostap: Jouni Malinen <j@w1.fi>
Once PBC overlap detected when using dynamic group interfaces, the wpa_s
corresponding to P2P group interface is freed. This patch avoids
accessing the wpa_s data structure after it is freed. This fixes a
possible crash in P2P client role in such a case.
Disable the direct connection when a TDLS peer stops responding
to packets, as indicated by the "LOW ACK" event coming from a driver.
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Cc: Kalyan C Gaddam <chakkal@iit.edu>
When a driver does not implement the TDLS_TEARDOWN operation internally,
send an explicit TDLS link teardown frame to the driver.
Change all teardown calls to use these calling semantics.
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Cc: Kalyan C Gaddam <chakkal@iit.edu>
Register for the TDLS discovery response public action frame in nl80211.
Print out a debug message when a Discovery Resp frame is received and
validated.
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Cc: Kalyan C Gaddam <chakkal@iit.edu>
IEEE Std 802.11-2007 7.3.2.2 demands that in order to join a BSS all
required basic rates have to be supported by the hardware.
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
This code was used only with driver_test.c to allow MLME operations
in hostapd to be tested without having to use a real radio. There
are no plans on extending this to any other use than testing and
mac80211_hwsim has now obsoled the need for this type of testing.
As such, we can drop this code from wpa_supplicant to clean up the
implementation of unnecessary complexity.
This offloads the station polling to driver wrappers, which may offload
it again to the driver. The hostap driver wrapper uses "real" data
frames while nl80211 uses null data frames.
Also add a specific event to indicate that a poll was successful for
future use with the nl80211 driver.
"hostapd_cli ess_disassoc (STA addr) (URL)" can now be used to send
an ESS Dissassociation Imminent notification to the STA. This event
is shown in wpa_supplicant ctrl_iface monitors (e.g., wpa_cli):
"WNM: ESS Disassociation Imminent - session_info_url=http://example.com/session/"
EVENT_WPS_BUTTON_PUSHED wpa_supplicant_event can now be used in
station mode driver_*.c to indicate that a push button has been
pushed. This will activate WPS PBC mode.
This patch uses sched_scan, if available, when the driver is
initialized. It also adds a couple of cancel operations where
appropriate.
Signed-off-by: Luciano Coelho <coelho@ti.com>
In new Linux kernel versions (>=3.0), nl80211 adds scheduled scan
capability. In order to use this feature to its full extent, we need
to support it in the wpa_supplicant core, so that it can also be used
by other drivers.
This commit adds initial scheduled scan support operations and events.
Signed-off-by: Luciano Coelho <coelho@ti.com>
This allows the AP to be selected based on the BSSID when WPA-PSK
is used with a passphrase. The PSK will be derived from the passphrase
after the SSID has been learned from scan results.
This implements GAS request mechanism that is aimed at being used to
replace use case specific GAS/ANQP implementations in the future.
Compared to the earlier implementation in P2P SD, this implementation
includes support for multiple concurrent requests and more thorough
validation of frames against the pending query data.
GAS header processing, including comeback and reassembly, are handled
within gas_query.c and the users of this module will only need to
provide the Query Request and process the (possibly reassembled)
Query Response.
If the driver indicates that it supports BSS selection (including
roaming within an ESS) with WPA_DRIVER_FLAGS_BSS_SELECTION, modify
ap_scan=1 mode to behave like ap_scan=2 mode for BSS selection.
The initial scan is still done to avoid the need for strict
configuration of or security parameters (e.g., to figure out whether
TKIP or CCMP is being used as the group cipher). However, when
requesting the driver to connect, the bssid and freq parameters are
not provided to leave the driver in control of selecting which BSS
to use and to allow the driver to decide when to roam.
Only accept Probe Request frames that have a Wildcard BSSID and a
destination address that matches with our P2P Device Address or is the
broadcast address per P2P specification 3.1.2.1.1.
Add support to wpa_supplicant for device-based GTK rekeying. In order to
support that, pass the KEK, KCK, and replay counter to the driver, and
handle rekey events that update the latter.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Previous ft_ies needs to be removed before supplicant starts a new FT
initial association and this requires the ft_used state to be cleared
here.
Signed-off-by: Hong Wu <hong.wu@dspg.com>
Regardless of how the AP mode is disabled, wpa_supplicant_ap_deinit()
must be called. Make sure this happens on all paths by calling the
deinit function from wpa_supplicant_mark_disassoc().
These checks were previously skipped if the scan result included WPA
or RSN IE. However, that can result in selecting a network that does
not match local configuration in some cases.
Processing of the scan results for RSN pre-authentication candidates
was moved to happen before the network was selected. This resulted in
all candidates being dropped due to no SSID having been configured.
Fix this by moving the processing to happen after the network has
been selected. Since the raw scan results are not available at that
point, use the BSS table instead of scan results to fetch the
information.
Both the SA and IEs from the received Probe Request frames must be
included and the Probe Request RX callback functions may assume that
these are not NULL.
It is now possible to configure the the time in seconds that
wpa_supplicant waits before requesting a new scan after failing to find
a suitable network in scan results.
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
If WPA/WPA2 was enabled in the configuration, the non-WPA exception
could allow an incorrect AP to be selected from scan results. Do
not use the exception if WPA/WPA2 is enabled in configuration.
Change the old design of running a single long living RSN IBSS
instance to keep a separate instance for each IBSS connection.
This fixes number of issues in getting keys set properly for
new connections and is in general quite a bit more correct
design.
Move the code snippet to switch on bgscan over to wpa_supplicant.c
from event.c, so that it can be activated on wpa_supplicant_set_state().
Also create a centralized place to switch off bgscan. bgscan is now
turned on in COMPLETED, not ASSOCIATED.
When wpa_s scans in AP mode, it doesn't propagate the scan event to the
AP code, so that code can get stuck if it uses the callbacks there.
Simply call them where appropriate.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This allows driver wrappers to indicate whether the association was
done using Association Request/Response or with Reassociation
Request/Response frames.
The DBus code will want to have perfect matching of dev_found and the
dev_lost it adds so it doesn't need to keep track internally. Enable
that with a new flag in the core that tracks whether we have already
notified about this -- the existing users can ignore it.
The part where this is always set to 1 if the new device is discovered
by a driver that has P2P in the driver is buggy -- the driver should
feed the P2P peer database and then that should feed the notification
here instead.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This embeds some information about each P2P peer that will be publically
visible in a struct that is shared.
The dev_found notification function is also passed the new struct, which
requires some work for the driver-based P2P management.
Signed-off-by: Konguraj(Raj) Kulanthaivel <konguraj.kulanthaivel@intel.com>
Signed-off-by: Fabien Marotte <fabienx.marotte@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
mac80211 authentication or association operation may get stuck for some
reasons, so wpa_supplicant better use an internal timer to recover from
this.
Signed-off-by: Ben Greear <greearb@candelatech.com>
When FT protocol run is completed with FT-EAP, the EAPOL state machine
needs to be notified of the completed authentication to make sure it
does not try to start new authentication.
This converts number of debugging messages to use wpa_msg() in order
to allow the interface name to be shown with the messages.
A new function, wpa_dbg(), is introduced to allow
CONFIG_NO_STDOUT_DEBUG=y builds to remove the debug strings. This is
otherwise identical with wpa_msg(), but it gets compiled out if stdout
debugging is disabled.
This is needed to allows WPS PBC session overlap detection to work
with drivers that process Probe Request frames internally. This
code is is run in hostapd, but the wpa_supplicant AP mode did not
have call to the hostapd_probe_req_rx() function even though it
registered handlers for hostapd Probe Request RX callbacks.
This was previously done for WPA/WPA2-Personal as part of association
processing when the driver is implementing 4-way handshake. The
portValid needs to be done for WPA/WPA2-Enterprise to get the proper
EAPOL authentication completed callback to configure PMK to the driver.
The driver may get confused if we set the initial TX GTK before having
fully configured and connected to an IBSS, so better delay this
operation until the connection (join/start IBSS) has been completed.
The proto configuration may be left to non-zero when moving from one
configuration to another. To avoid misidentifying a network
configuration as enabling WPA, check key_mgmt field, too.
This adds partial callbacks and events to allow P2P management to be
implemented in a driver/firmware. This is not yet complete and is
very much subject to change in the future.
The nl80211 driver can report low ACK condition (in fact it reports
complete loss right now only). Use that, along with a config option, to
disconnect stations when the data connection is not working properly,
e.g., due to the STA having went outside the range of the AP. This is
disabled by default and can be enabled with disassoc_low_ack=1 in
hostapd or wpa_supplicant configuration file.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The WPS mode was already verified when the AP was configured for
WPA/WPA2, but this was not done with AP that was in open mode.
Fix this by allowing wpa_supplicant_ssid_bss_match() to be called
in non-WPA configuration, too. With this change, wps_pbc BSSID
command will wait until the specified target AP is in active PBC
mode before trying to connect to it.
If a station received unprotected Deauthentication or Disassociation
frame with reason code 6 or 7 from the current AP, there may be a
mismatch in association state between the AP and STA. Verify whether
this is the case by using SA Query procedure. If not response is
received from the AP, deauthenticate.
This implementation is only for user space SME with
driver_nl80211.c.
Some new code I'm working on will need the scan_res_handler assigned all
the time in certain circumstances, so the easiest way is to reset it
within the handler. This is currently prevented by the way the code in
the event handler works -- change that to permit such usage.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When controlling multiple virtual interfaces on the same physical
radio, share the scan results events with sibling interfaces. This
decreases the time it takes to connect many virtual interfaces.
This is currently only supported on Linux with cfg80211-based
drivers when using nl80211 or wext driver interface.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Move the previously SME specific optimization code into generic
function that can be used from non-SME code, too, and use it to
handle disconnection events. In other words, allow disconnection
event to trigger similar optimized scanning case to handle a
common load balancing mechanism. If there is another BSS in the
same ESS when we receive a disconnection event, scan only the
known frequencies of such other BSSes on the next attempt to
speed up recovery.
The special case of requiring blacklisting count to be 2 or higher
is only needed when more than a single network is currently enabled.
As such, we should not do that when only a single network is enabled.
This make the station more likely to follow network side load
balancing attempts where the current AP may disassociate us with
an assumption that we would move to another AP.
assoc_freq needs to be cleared when an interface gets disconnected.
This fixes an issue where P2P Action frame transmission may fail
because of missing remain-on-channel operation when using the same
interface for group operations (or non-P2P connections) and P2P
management operations.
The wpa_supplicant_event() EVENT_TX_STATUS ack field needs to be
converted to use wpas_send_action_tx_status()
enum p2p_send_action_result in this case, too, to avoid getting
incorrect TX status for P2P processing.
By default, make hostapd and wpa_supplicant maintain an internal
entropy pool that is fed with following information:
hostapd:
- Probe Request frames (timing, RSSI)
- Association events (timing)
- SNonce from Supplicants
wpa_supplicant:
- Scan results (timing, signal/noise)
- Association events (timing)
The internal pool is used to augment the random numbers generated
with the OS mechanism (os_get_random()). While the internal
implementation is not expected to be very strong due to limited
amount of generic (non-platform specific) information to feed the
pool, this may strengthen key derivation on some devices that are
not configured to provide strong random numbers through
os_get_random() (e.g., /dev/urandom on Linux/BSD).
This new mechanism is not supposed to replace proper OS provided
random number generation mechanism. The OS mechanism needs to be
initialized properly (e.g., hw random number generator,
maintaining entropy pool over reboots, etc.) for any of the
security assumptions to hold.
If the os_get_random() is known to provide strong ramdom data (e.g., on
Linux/BSD, the board in question is known to have reliable source of
random data from /dev/urandom), the internal hostapd random pool can be
disabled. This will save some in binary size and CPU use. However, this
should only be considered for builds that are known to be used on
devices that meet the requirements described above. The internal pool
is disabled by adding CONFIG_NO_RANDOM_POOL=y to the .config file.
The driver wrapper may now indicate the preferred channel (e.g., based
on scan results) on both 2.4 GHz and 5 GHz bands (and an overall best
frequency). When setting up a GO, this preference information is used
to select the operating channel if configuration does not include
hardcoded channel. Similarly, this information can be used during
GO Negotiation to indicate preference for a specific channel based
on current channel conditions.
p2p_group_add command can now use special values (freq=2 and freq=5)
to indicate that the GO is to be started on the specified band.
Commit d8d940b746 introduced a regression
that prevented TSN APs from being used with WEP since the AP was
rejected if it advertised WPA or RSN IE when we were configured to use
WEP. Resolve this by checking whether the AP is advertising a TSN, i.e.,
whether the AP allows WEP to be used as a group cipher. If so, allow
the AP to be selected if we are configured to use static WEP or
IEEE 802.1X (non-WPA).
It should be noted that this is still somewhat more restricted in AP
selection than earlier wpa_supplicant branches (0.7.x or older) that
ignore the WPA/RSN IE completely when configured for non-WPA.
Add a new driver event, EVENT_INTERFACE_UNAVAILABLE, for indicating
that the driver is not able to continue operating the virtual
interface in its current mode anymore, e.g., due to operating
channel for GO interface forced to a DFS channel by another virtual
interface.
When this happens for a P2P group interface, the P2P group will
be terminated and P2P-GROUP-REMOVED event shows the reason for
this as follows:
P2P-GROUP-REMOVED wlan0 GO reason=UNAVAILABLE
The driver wrapper may indicate EVENT_CHANNEL_LIST_CHANGED before
completing init(). This would likely result in segfault when driver
channel list is being read as part of processing this event when
P2P is enabled.
The workaround to ignore no ctrl::ack received for GO Negotiation
Confirmation frame was only supposed to be used when the frame was
actually transmitted and just the ack was not received. However, due
to the way the driver failure on transmitting the frame were reported,
this ended up getting applied for all failures in sending the GO
Negotiation Confirmation frame.
Improve this by providing a mechanism to indicate whether send_action
operations fail locally before the frame was actually transmitted or
because of not receiving ack frame after having transmitted the frame.
Previously, wpa_supplicant remaining in scanning state without
trying to connect, but there is no particular need to do that.
Instead, cancel WPS operation completely whenever PBC session
overlap is detected.
Disconnection event may be received while in associating state.
Previously, wpa_supplicant could get stuck not trying to reconnect
in that case at least with nl80211. Allow scan request in this
state to avoid the issue. This helps especially with APs that do
load balancing by sending Deauthentication frame as a response to
Reassociation Request frame after successful Authentication frame
exchange.
ctrl_interface STA_AUTOCONNECT command can now be used to disable
automatic reconnection on receiving disconnection event. The default
behavior is for wpa_supplicant to try to reconnect automatically, i.e.,
to maintain previous behavior.
The overlap condition cannot disappear before group formation timeout
hits, so there is no point in continuing in this case and failure can
be indicated immediately.
If CONFIG_WPS_STRICT is set, validate WPS IE(s) in management frames and
reject the frames if any of the mandatory attributes is missing or if an
included attribute uses an invalid value. In addition, verify that all
mandatory attributes are included and have valid values in the WSC
messages.
Verify that the driver wrapper is using a valid deauth/disassoc
event before dereferencing the addr pointer. The address is required
to be set in AP mode, but it is safer to verify this here than to
trust on all driver wrappers doing the correct thing.
Commit d8d940b746 broke the logic on
iterating through all configured network blocks. This was supposed
to continue the loop on mismatch to allow other than the first
configured network to be found.
This removes quite a bit of duplicated code and allows network block
priority configuration to be used to prefer unprotected networks and
also allows use on open network with good signal strength even if
scan results show a protected network with marginal signal strength
that does not allow it to be used.
This is needed to avoid trying to reassociate based on new scan
results when using wpa_supplicant to control AP mode. This could
happen if something external triggered the driver to run a scan.
It is possible that l2_packet is not used with wpa_supplicant
in some cases, so better make sure we do not end up notifying
l2_packet code about authentications unless it was actually
initialized in the first place.
Add a new wpa_supplicant state: interface disabled. This can be used
to allow wpa_supplicant to be running with the network interface even
when the driver does not actually allow any radio operations (e.g.,
due to rfkill).
Allow driver_nl80211.c and driver_wext.c to start while rfkill is in
blocked state (i.e., when ifconfig up fails) and process rfkill
events to block/unblock WLAN.
This adds more details into the CTRL-EVENT-DISCONNECTED event to
make it easier to figure out which network was disconnected in some
race conditions and to what could have been the reason for
disconnection. The reason code is currently only available with
the nl80211 driver wrapper.
'wpa_cli roam <bssid>' can now be used to test roaming within an ESS
(e.g., for FT over-the-air). This command will bypass a new scan and
will select the BSS based on the specified BSSID. It is responsibility
of the caller to make sure that the target AP is in the BSS table.
This can be done, e.g., by running a scan before the roam command,
if needed.
Instead of parsing the IEs in the callers, use the already existing
parser in wpa_ft.c to handle MDIE and FTIE from initial MD association
response. In addition, this provides more complete access to association
response IEs to FT code which will be needed to fix FT 4-way handshake
message 2/4.
This allows bgscan modules to use more information to decide on when
to perform background scans. bgscan_simple can now change between
short and long background scan intervals based on signal strength
and in addition, it can trigger immediate scans when the signal
strength is detected to be dropping.
bgscan_simple takes following parameters now:
short interval:signal strength threshold:long interval
For example:
bgscan="simple:30:-45:300"
This can be used to limit which frequencies are considered when
selecting a BSS. This is somewhat similar to scan_freq, but will
also affect any scan results regardless of which program triggered
the scan.
Previously, this was only done with userspace MLME (i.e., driver_test.c);
now, driver_nl80211.c can deliver the FT Action Response (FT-over-DS)
for processing. The reassociation after successful FT Action frame
exchange is not yet implemented.
This is needed to allow the BSS table entry for the previously used
BSS to be removed. Now wpa_bss_in_use() can return 0 for the last BSS
that was used as soon as deauthentication/disassociation event has been
received.
When multiple APs are present in scan results with similar signal
strength, wpa_supplicant may end up bounching between them frequently
whenever new scan results are available (e.g., due to periodic scans
requested by NetworkManager). This can result in unnecessary roaming
and in case of the current cfg80211 version, to frequent network
disconnections.
Do not request a roam if the current BSS is still present in the scan
results and the selected BSS is in the same ESS and has only a slighly
stronger signal strength.
The three existing enums were already depending on using the same
values in couple of places and it is just simpler to standardize on
one of these to avoid need for mapping between different enums for
the exact same thing.
This fits better in wpa_supplicant/scan.c. Couple of remaining
scan_helpers.c functions are currently used in driver wrappers,
but they can likely be removed in the future.
Get rid of wpa_supplicant_sta_rx() and add a new driver event that is
marked to be used only with driver_test.c. In addition, remove this
functionality from privsep wrapper. This is only use for client mode
MLME testing with driver_test.c.
Get more information about scans when updating BSS table information.
This allows the missing-from-scans expiration rule to work properly
when only partial set of channels or SSIDs are being scanned.
Replace driver wrapper calls to hostapd_tx_status(),
hostapd_rx_from_unknown_sta(), hostapd_mgmt_rx(), and
hostapd_mgmt_tx_cb() with new generic driver events
EVENT_TX_STATUS, EVENT_RX_FROM_UNKNOWN, and EVENT_RX_MGMT.
This cleans up lot of the driver wrapper code to be less dependent
on whether it is being used within wpa_supplicant AP mode or hostapd.
Wait for connection (IBSS join completed) event before marking state
completed. In addition, do not use the station mode authentication
timeout since that can trigger full disconnection from IBSS when
there is a timeout with just one of the peers.
cfg80211/mac80211 can get into somewhat confused state if the AP only
disassociates us and leaves us in authenticated state. For now, force
the state to be cleared with deauthentication to avoid confusing errors
if we try to associate with the AP again. This gets rid of 30 second
delay (scan timeout) in cases where only a disassociation frame is
received from the AP.
This makes it clearer which files are including header from src/common.
Some of these cases should probably be cleaned up in the future not to
do that.
In addition, src/common/nl80211_copy.h and wireless_copy.h were moved
into src/drivers since they are only used by driver wrappers and do not
need to live in src/common.
This avoids passing the raw scan results into the RSN code and by
doing so, removes the only dependency on src/drivers from the
src/rsn_supp code (or from any src subdirectory for that matter).
This is like wpa_msg(), but the output is directed only to
ctrl_interface listeners. In other words, the output will not be
shown on stdout or in syslog.
Change scan result reporting to use wpa_msg_ctrl() for
CTRL-EVENT-SCAN-RESULTS message at info level and wpa_printf() at
debug level to avoid showing scan result events in syslog in the
common configuration used with NetworkManager.
Previously, APs that were hiding SSID (zero-length SSID IE in
Beacon frames) could have been selected when wildcard SSID matching
was used. This would result in failed association attempt since
the client does not know the correct SSID. This can slow down WPS
which is often using wildcard SSID matching.
Ignore BSSes without known SSID in the scan results when selecting
which BSS to use.
mac80211 does not currently allow (re)authentication when we are already
authenticated. In order to work around this, force deauthentication if
nl80211 authentication command fails with EALREADY. Unfortunately, the
workaround code in driver_nl80211.c alone is not enough since the
following disconnection event would clear wpa_supplicant authentication
state. To handle this, add some code to restore authentication state
when using userspace SME.
This workaround will hopefully become unnecessary in some point should
mac80211 start accepting new authentication requests even when in
authenticated state.
If no BSSes/IBSSes matching the enabled networks are found in the scan
results, IBSS/AP mode network (if configured) can be created in
ap_scan=1 mode instead of requiring ap_scan=2 mode to be used whenever
using IBSS or AP mode.
Current wpa_supplicant has a bug with WEP keys, it adds a zero-length
sequence counter field to netlink which the kernel doesn't accept.
Additionally, the kernel API slightly changed to accept keys only when
connected, so we need to send it the keys after that. For that to work
with shared key authentication, we also include the default WEP TX key
in the authentication command.
To upload the keys properly _after_ associating, add a new flag
WPA_DRIVER_FLAGS_SET_KEYS_AFTER_ASSOC_DONE indicating that the driver
needs the keys at that point and not earlier.
This allows background scanning and roaming decisions to be contained in
a single place based on a defined set of notification events which will
hopefully make it easier to experiment with roaming improvements. In
addition, this allows multiple intra-ESS roaming policies to be used
(each network configuration block can configure its own bgscan module).
The beacon loss and signal strength notifications are implemented for
the bgscan API, but the actual events are not yet available from the
driver.
The included sample bgscan module ("simple") is an example of what can
be done with the new bgscan mechanism. It requests periodic background
scans when the device remains associated with an ESS and has couple of
notes on what a more advanced bgscan module could do to optimize
background scanning and roaming. The periodic scans will cause the scan
result handler to pick a better AP if one becomes available. This bgscan
module can be taken into use by adding bgscan="simple" (or
bgscan="simple:<bgscan interval in seconds>") into the network
configuration block.
