Modern kernels ~5.4+ have changed the way lost beacons are
reported and effectively make the lost beacon event useless
because it is immediately followed by a disconnect event. This
does not allow IWD enough time to do much of anything before
the disconnect comes in and we are forced to fully re-connect
to a different AP.
periodic_scan_stop is called whenever we exit the autoscan state but a
periodic scan may not be running at the time. If we have a
user-triggered scan running, or the autoconnect_quick scan, and we reset
Scanning to false before that scan finished, a client could en up
calling GetOrderedNetwork too early and not receiving the scan results.
ConnectHiddenNetwork can be seen a triggering this sequence:
1. the active scan,
2. the optional agent request,
3. the Authentication/Association/4-Way Handshake/netconfig,
4. connected state
Currently Disconnect() interrupts 3 and 4, allow it to also interrupt
state 1. It's difficult to tell whether we're in state 2 from within
station.c.
For multi-bss networks its nice to know which BSS is being connected
to. The ranking can hint at it, but blacklisting or network capabilities
could effect which network is actually chosen. An explicit debug print
makes debugging much easier.
Move the update of station->networks_sorted order to before we set
station->connected_network NULL to avoid a crash when we attempt to
use the NULL pointer.
Besides being undefined behaviour, signed integer overflow can cause
unexpected comparison results. In the case of network_rank_compare(),
a connected network with rank INT_MAX would cause newly inserted
networks with negative rank to be inserted earlier in the ordered
network list. This is reflected in the GetOrderedMethods() DBus method
as can be seen in the following iwctl output:
[iwd]# station wlan0 get-networks
Network name Security Signal
----------------------------------------------------
BEOLAN 8021x **** }
BeoBlue psk *** } all unknown,
UI_Test_Network psk *** } hence assigned
deneb_2G psk *** } negative rank
BEOGUEST open **** }
> titan psk ****
Linksys05274_5GHz_dmt psk ****
Lyngby-4G-4 5GHz psk ****
Doing so ensures that the currently connected network is always at the
beginning of the list. Previously, the list would only get updated after
a scan.
This fixes the documented behaviour of GetOrderedNetworks() DBus method,
which states that the currently connected network is always at the
beginning of the returned array.
To use the wiphy radio work queue, scanning mostly remained the same.
start_next_scan_request was modified to be used as the work callback,
as well as not start the next scan if the current one was done
(since this is taken care of by wiphy work queue now). All
calls to start_next_scan_request were removed, and more or less
replaced with wiphy_radio_work_done.
scan_{suspend,resume} were both removed since radio management
priorities solve this for us. ANQP requests can be inserted ahead of
scan requests, which accomplishes the same thing.
Before connecting to a hidden network we must scan. During this scan
if another connection attempt comes in the expected behavior is to
abort the original connection. Rather than waiting for the scan to
complete, then canceling the original hidden connection we can just
cancel the hidden scan immediately, reply to dbus, and continue with
the new connection attempt.
The new frame-xchg module now handles a lot of what ANQP used to do. ANQP
now does not need to depend on nl80211/netdev for building and sending
frames. It also no longer needs any of the request lookups, frame watches
or to maintain a queue of requests because frame-xchg filters this for us.
From an API perspective:
- anqp_request() was changed to take the wdev_id rather than ifindex.
- anqp_cancel() was added so that station can properly clean up ANQP
requests if the device disappears.
During testing a bug was also fixed in station on the timeout path
where the request queue would get popped twice.
When roaming, iwd tries to scan a limited number of frequencies to keep
the roaming latency down. Ideally the frequency list would come in from
a neighbor report, but if neighbor reports are not supported, we fall
back to our internal database for known frequencies of this network.
iwd tries to keep the number of scans down to a bare minimum, which
means that we might miss APs that are in range. This could happen
because the user might have moved physically and our frequency list is
no longer up to date, or if the AP frequencies have been reconfigured.
If a limited scan fails to find any good roaming candidates, re-attempt
a full scan right away.
If the roam failed and we are no longer connected, station_disassociated
is called which ends up calling station_roam_state_clear. Thus
resetting the variables is not needed. Reflow the logic to make this a
bit more explicit.
If the roam attempt fails, do not reset this to false. Generally this
is set by the fact that we lost beacon and to not attempt neighbor
reports, etc. This hint should be preserved across roam attempts.
Right now, if the connection fails, then network always thinks that the
password should be re-asked. Loosen this to only do so if the
connection failed at least in the handshake phase. If the connection
failed due to Association / Authentication timeout, it is likely that
something is wrong with the AP and it can't respond.
This is to allow network to watch for ANQP activity in order to
fix the race condition between scanning finishing and ANQP finishing.
Without this it is possible for a DBus Connect() to come in before
ANQP has completed and causing the network to return NotConfigured,
when its actually in the process of obtaining all the network info.
The watch was made globally in station due to network not having
a station object until each individual network is created. Adding a
watch during network creation would result in many watchers as well
as a lot of removal/addition as networks are found and lost.
Change signature of network_connect_new_hidden_network to take
reference to the caller's l_dbus_message struct. This allows to
set the caller's l_dbus_message struct to NULL after replying in
the case of a failure.
==201== at 0x467C15: l_dbus_message_unref (dbus-message.c:412)
==201== by 0x412A51: station_hidden_network_scan_results (station.c:2504)
==201== by 0x41EAEA: scan_finished (scan.c:1505)
==201== by 0x41EC10: get_scan_done (scan.c:1535)
==201== by 0x462592: destroy_request (genl.c:673)
==201== by 0x462987: process_unicast (genl.c:988)
==201== by 0x462987: received_data (genl.c:1087)
==201== by 0x45F5A2: io_callback (io.c:126)
==201== by 0x45E8FD: l_main_iterate (main.c:474)
==201== by 0x45E9BB: l_main_run (main.c:521)
==201== by 0x45EBCA: l_main_run_with_signal (main.c:643)
==201== by 0x403B15: main (main.c:512)
Introduce hidden_pending to keep reference to the dbus message object
while we wait for the scan results to be returned while trying to
connect to a hidden network. This simplifies the logic by separating it
into two independent logical units: scanning, connecting and eliminates
a possibility of a memory leak in the case when Network.Connect being
initiated while Station.ConnectHiddenNetwork is in progress.
If a connection is initiated (via dbus) while a quick scan is in
progress, the quick scan will be aborted. In this case,
station_quick_scan_results will always transition to the
AUTOCONNECT_FULL state regardless of whether it should or not.
Fix this by making sure that we only enter AUTOCONNECT_FULL if we're
still in the AUTOCONNECT_QUICK state.
Reported-by: Alvin Šipraga <alsi@bang-olufsen.dk>
This patch adds two new options to a network provisioning file:
AlwaysRandomizeAddress={true,false}
If true, IWD will randomize the MAC address on each connection to this
network. The address does not persists between connections, any new
connection will result in a different MAC.
AddressOverride=<MAC>
If set, the MAC address will be set to <MAC> assuming its a valid MAC
address.
These two options should not be used together, and will only take effect
if [General].AddressRandomization is set to 'network' in the IWD
config file.
If neither of these options are set, and [General].AddressRandomization
is set to 'network', the default behavior remains the same; the MAC
will be generated deterministically on a per-network basis.
If a scan is requested during the middle of a connection we should
return busy instead of attempting the scan. The kernel ends up coming
back with not supported in this case, which is misleading and
difficult to debug.
For Radio Resource Management (RRM) we will need access to the currently
connected BSS as well as the last scan results in order to do certain
kinds of requested measurements.
On EAP events, call the handshake_event handler with the new event type
HANDSHAKE_EVENT_EAP_NOTIFY isntead of the eapol_event callback.
This allows the handler to be set before calling
netdev_connect/netdev_connect_wsc. It's also in theory more type-safe
because we don't need the cast in netdev_connect_wsc anymore.
Convert the handshake event callback type to use variable argument
list to allow for more flexibility in event-specific arguments
passed to the callbacks.
Note the uint16_t reason code is promoted to an int when using variable
arguments so va_arg(args, int) has to be used.
Previously, station state 'connected' used to identify an interface associated
with AP. With the introduction of netconfig, an interface is assumed to be
connected after the IP addresses have been assigned to it. If netconfig is
disabled, the behavior remains unchanged.
As a first step to enable the usage of netconfig in ead and
prospective transition to be a part of ell, the public API for
creation and destruction of the netconfig objects has been
renamed and changed. Instead of hiding the netconfig objects inside
of netconfig module, the object is now passed back to the caller.
The internal queue of netconfig objects remains untouched, due
to limitations in ell’s implementation of rtnl. After the proper
changes are done to ell, netconfig_list is expected to be removed
from netconfig module.
If neighbor reports are unavailable, or the report yielded no
results we can quickly scan for only known frequencies. This
changes the original behavior where we would do a full scan
in this case.
Station was building up the HS20 elements manually. Now we can
use this new API and let network take care of the complexity
of building network specific vendor IEs.
Since hotspot networks may require ANQP the autoconnect loop needed to
be delayed until after the ANQP results came back and the network
objects were updated. If there are hotspot networks in range ANQP will
be performed and once complete autoconnect will begin for all networks
including hotspots. If no hotspots are in range autoconnect will
proceed as it always has.
Note: Assuming hotspots are in range this will introduce some delay
in autoconnecting to any network since ANQP must come back. The full
plan is to intellegently decide when and when not to do ANQP in order
to minimize delays but since ANQP is disabled by default the behavior
introduced with this patch is acceptable.
