The 8021x offloading procedure still does EAP in userspace which
negotiates the PMK. The kernel then expects to obtain this PMK
from userspace by calling SET_PMK. This then allows the firmware
to begin the 4-way handshake.
Using __eapol_install_set_pmk_func to install netdev_set_pmk,
netdev now gets called into once EAP finishes and can begin
the final userspace actions prior to the firmware starting
the 4-way handshake:
- SET_PMK using PMK negotiated with EAP
- Emit SETTING_KEYS event
- netdev_connect_ok
One thing to note is that the kernel provides no way of knowing if
the 4-way handshake completed. Assuming SET_PMK/SET_STATION come
back with no errors, IWD assumes the PMK was valid. If not, or
due to some other issue in the 4-way, the kernel will send a
disconnect.
This adds a new type for 8021x offload as well as support in
building CMD_CONNECT.
As described in the comment, 8021x offloading is not particularly
similar to PSK as far as the code flow in IWD is concerned. There
still needs to be an eapol_sm due to EAP being done in userspace.
This throws somewhat of a wrench into our 'is_offload' cases. And
as such this connection type is handled specially.
802.1x offloading needs a way to call SET_PMK after EAP finishes.
In the same manner as set_tk/gtk/igtk a new 'install_pmk' function
was added which eapol can call into after EAP completes.
The timeout functionality was removed from the core SAE
implementation as it causes issues with kernel behavior.
Because of this the timeout tests are no longer valid,
nor is a few asserts in the end-to-end test.
The chances were extremely low, but using l_idle_oneshot
could end up causing a invalid memory access if the netdev
went down while waiting for the disconnect idle callback.
Instead netdev can keep track of the idle with l_idle_create
and remove it if the netdev goes down prior to the idle callback.
This fixes an infinite loop issue when authenticate frames time
out. If the AP is not responding IWD ends up retrying indefinitely
due to how SAE was handling this timeout. Inside sae_auth_timeout
it was actually sending another authenticate frame to reject
the SAE handshake. This, again, resulted in a timeout which called
the SAE timeout handler and repeated indefinitely.
The kernel resend behavior was not taken into account when writing
the SAE timeout behavior and in practice there is actually no need
for SAE to do much of anything in response to a timeout. The
kernel automatically resends Authenticate frames 3 times which mirrors
IWDs SAE behavior anyways. Because of this the authenticate timeout
handler can be completely removed, which will cause the connection
to fail in the case of an autentication timeout.
This crash was caused from the disconnect_cb being called
immediately in cases where send_disconnect was false. The
previous patch actually addressed this separately as this
flag was being set improperly which will, indirectly, fix
one of the two code paths that could cause this crash.
Still, there is a situation where send_disconnect could
be false and in this case IWD would still crash. If IWD
is waiting to queue the connect item and netdev_disconnect
is called it would result in the callback being called
immediately. Instead we can add an l_idle as to allow the
callback to happen out of scope, which is what station
expects.
Prior to this patch, the crashing behavior can be tested using
the following script (or some variant of it, your system timing
may not be the same as mine).
iwctl station wlan0 disconnect
iwctl station wlan0 connect <network1> &
sleep 0.02
iwctl station wlan0 connect <network2>
++++++++ backtrace ++++++++
0 0x7f4e1504e530 in /lib64/libc.so.6
1 0x432b54 in network_get_security() at src/network.c:253
2 0x416e92 in station_handshake_setup() at src/station.c:937
3 0x41a505 in __station_connect_network() at src/station.c:2551
4 0x41a683 in station_disconnect_onconnect_cb() at src/station.c:2581
5 0x40b4ae in netdev_disconnect() at src/netdev.c:3142
6 0x41a719 in station_disconnect_onconnect() at src/station.c:2603
7 0x41a89d in station_connect_network() at src/station.c:2652
8 0x433f1d in network_connect_psk() at src/network.c:886
9 0x43483a in network_connect() at src/network.c:1183
10 0x4add11 in _dbus_object_tree_dispatch() at ell/dbus-service.c:1802
11 0x49ff54 in message_read_handler() at ell/dbus.c:285
12 0x496d2f in io_callback() at ell/io.c:120
13 0x495894 in l_main_iterate() at ell/main.c:478
14 0x49599b in l_main_run() at ell/main.c:521
15 0x495cb3 in l_main_run_with_signal() at ell/main.c:647
16 0x404add in main() at src/main.c:490
17 0x7f4e15038b25 in /lib64/libc.so.6
The send_disconnect flag was being improperly set based only
on connect_cmd_id being zero. This does not take into account
the case of CMD_CONNECT having finished but not EAPoL. In this
case we do need to send a disconnect.
This adds a new connection type, TYPE_PSK_OFFLOAD, which
allows the 4-way handshake to be offloaded by the firmware.
Offloading will be used if the driver advertises support.
The CMD_ROAM event path was also modified to take into account
handshake offloading. If the handshake is offloaded we still
must issue GET_SCAN, but not start eapol since the firmware
takes care of this.
Until now FT was only supported via Auth/Assoc commands which barred
any fullmac cards from using FT AKMs. With PSK offload support these
cards can do FT but only when offloading is used.
In the FW scan callback eapol was being stared unconditionally which
isn't correct as roaming on open networks is possible. Instead check
that a SM exists just like is done in netdev_connect_event.
This should have been updated along with the connect and roam
event separation. Since netdev_connect_event is not being
re-used for CMD_ROAM the comment did not make sense anymore.
Still, there needs to be a check to ensure we were not disconnected
while waiting for GET_SCAN to come back.
netdev_connect_event was being reused for parsing of CMD_ROAM
attributes which made some amount of sense since these events
are nearly identical, but due to the nature of firmware roaming
there really isn't much IWD needs to parse from CMD_ROAM. In
addition netdev_connect_event was getting rather complicated
since it had to handle both CMD_ROAM and CMD_CONNECT.
The only bits of information IWD needs to parse from CMD_ROAM
is the roamed BSSID, authenticator IEs, and supplicant IEs. Since
this is so limited it now makes little sense to reuse the entire
netdev_connect_event function, and intead only parse what is
needed for CMD_ROAM.
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.
Currently netdev handles SoftMac and FullMac drivers mostly in the same
way, by building CMD_CONNECT nl80211 commands and letting the kernel
figure out the details. Exceptions to this are FILS/OWE/SAE AKMs which
are only supported on SoftMac drivers by using
CMD_AUTHENTICATE/CMD_ASSOCIATE.
Recently, basic support for SAE (WPA3-Personal) offload on FullMac cards
was introduced. When offloaded, the control flow is very different than
under typical conditions and required additional logic checks in several
places. The logic is now becoming quite complex.
Introduce a concept of a connection type in order to make it clearer
what driver and driver features are being used for this connection. In
the future, connection types can be expanded with 802.1X handshake
offload, PSK handshake offload and CMD_EXTERNAL_AUTH based SAE
connections.
Commit 6e8b76527 added a switch statement for AKM suites which
was not correct as this is a bitmask and may contain multiple
values. Intead we can rely on wiphy_select_akm which is a more
robust check anyways.
Fixes: 6e8b765278 ("wiphy: add check for CMD_AUTH/CMD_ASSOC support")
If there is an associate timeout, retry a few times in case
it was just a fluke. At this point SAE is fully negotiated
so it makes sense to attempt to save the connection.
Any auth proto which did not implement the assoc_timeout handler
could end up getting 'stuck' forever if there was an associate
timeout. This is because in the event of an associate timeout IWD
only sets a few flags and relies on the connect event to actually
handle the failure. The problem is a connect event never comes
if the failure was a timeout.
To fix this we can explicitly fail the connection if the auth
proto has not implemented assoc_timeout or if it returns false.
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.
Converts ie_rsn_akm_suite values (and WPA1 hint) into a more
human readable security string such as:
WPA2-Personal, WPA3-Personal, WPA2-Personal + FT etc.
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.
SAE offload support requires some minor tweaks to CMD_CONNECT
as well as special checks once the connect event comes in. Since
at this point we are fully connected.
