Several tests do not pass due to some additional changes that have
not been merged. Remove these cases and add some hardening after
discovering some unfortunate wpa_supplicant behavior.
- Disable p2p in wpa_supplicant. With p2p enabled an extra device
is created which starts receiving DPP frames and printing
confusing messages.
- Remove extra asserts which don't make sense currently. These
will be added back later as future additions to PKEX are
upstreamed.
- Work around wpa_supplicant retransmit limitation. This is
described in detail in the comment in pkex_test.py
- wait_for_event was returning a list in certain cases, not the
event itself
- The configurator ID was not being printed (',' instead of '%')
- The DPP ID was not being properly waited for with PKEX
With the addition of DPP PKEX autotests some of the timeouts are
quite long and hit test-runners maximum timeouts. For UML we should
allow this since time-travel lets us skip idle waits. Move the test
timeout out of a global define and into the argument list so QEMU
and UML can define it differently.
The StartConfigurator() call was left out since there would be no
functional difference to the user in iwctl. Its expected that
human users of the shared code API provide the code/id ahead of
time, i.e. use ConfigureEnrollee/StartEnrollee.
Check that enough space for newline and 0-byte is left in line.
This fixes a buffer overflow on specific completion results.
Reported-By: Leona Maroni <dev@leona.is>
Adds a configurator variant to be used along side an agent. When
called the configurator will start and wait for an initial PKEX
exchange message from an enrollee at which point it will request
the code from an agent. This provides more flexibility for
configurators that are capable of configuring multiple enrollees
with different identifiers/codes.
Note that the timing requirements per the DPP spec still apply
so this is not meant to be used with a human configurator but
within an automated agent which does a quick lookup of potential
identifiers/codes and can reply within the 200ms window.
The PKEX configurator role is currently limited to being a responder.
When started the configurator will listen on its current operating
channel for a PKEX exchange request. Once received it and the
encrypted key is properly decrypted it treats this peer as the
enrollee and won't allow configurations from other peers unless
PKEX is restarted. The configurator will encrypt and send its
encrypted ephemeral key in the PKEX exchange response. The enrollee
then sends its encrypted bootstrapping key (as commit-reveal request)
then the same for the configurator (as commit-reveal response).
After this, PKEX authentication begins. The enrollee is expected to
send the authenticate request, since its the initiator.
This is the initial support for PKEX enrollees acting as the
initiator. A PKEX initiator starts the protocol by broadcasting
the PKEX exchange request. This request contains a key encrypted
with the pre-shared PKEX code. If accepted the peer sends back
the exchange response with its own encrypted key. The enrollee
decrypts this and performs some crypto/hashing in order to establish
an ephemeral key used to encrypt its own boostrapping key. The
boostrapping key is encrypted and sent to the peer in the PKEX
commit-reveal request. The peer then does the same thing, encrypting
its own bootstrapping key and sending to the initiator as the
PKEX commit-reveal response.
After this, both peers have exchanged their boostrapping keys
securely and can begin DPP authentication, then configuration.
For now the enrollee will only iterate the default channel list
from the Easy Connect spec. Future upates will need to include some
way of discovering non-default channel configurators, but the
protocol needs to be ironed out first.
Stop() will now return NotFound if DPP is not running. This causes
the DPP test to fail since it calls this regardless if the protocol
already stopped. Ignore this exception since tests end in various
states, some stopped and some not.
PKEX and DPP will share the same state machine since the DPP protocol
follows PKEX. This does pose an issue with the DBus interfaces
because we don't want DPP initiated by the SharedCode interface to
start setting properties on the DeviceProvisioning interface.
To handle this a dpp_interface enum is being introduced which binds
the dpp_sm object to a particular interface, for the life of the
protocol run. Once the protocol finishes the dpp_sm can be unbound
allowing either interface to use it again later.
This mispelling was present in the configuration, so I retained parsing
of the legacy BandModifier*Ghz options for compatibility. Without this
change anyone spelling GHz correctly in their configs would be very
confused.
PKEX is part of the WFA EasyConnect specification and is
an additional boostrapping method (like QR codes) for
exchanging public keys between a configurator and enrollee.
PKEX operates over wifi and requires a key/code be exchanged
prior to the protocol. The key is used to encrypt the exchange
of the boostrapping information, then DPP authentication is
started immediately aftewards.
This can be useful for devices which don't have the ability to
scan a QR code, or even as a more convenient way to share
wireless credentials if the PSK is very secure (i.e. not a
human readable string).
PKEX would be used via the three DBus APIs on a new interface
SharedCodeDeviceProvisioning.
ConfigureEnrollee(a{sv}) will start a configurator with a
static shared code (optionally identifier) passed in as the
argument to this method.
StartEnrollee(a{sv}) will start a PKEX enrollee using a static
shared code (optionally identifier) passed as the argument to
the method.
StartConfigurator(o) will start a PKEX configurator and use the
agent specified by the path argument. The configurator will query
the agent for a specific code when an enrollee sends the initial
exchange message.
After the PKEX protocol is finished, DPP bootstrapping keys have
been exchanged and DPP Authentication will start, followed by
configuration.
Beacon loss handling was removed in the past because it was
determined that this even always resulted in a disconnect. This
was short sighted and not always true. The default kernel behavior
waits for 7 lost beacons before emitting this event, then sends
either a few nullfuncs or probe requests to the BSS to determine
if its really gone. If these come back successfully the connection
will remain alive. This can give IWD some time to roam in some
cases so we should be handling this event.
Since beacon loss indicates a very poor connection the roam scan
is delayed by a few seconds in order to give the kernel a chance
to send the nullfuncs/probes or receive more beacons. This may
result in a disconnect, but it would have happened anyways.
Attempting a roam mainly handles the case when the connection can
be maintained after beacon loss, but is still poor.
This is being done to allow the DPP module to work correctly. DPP
currently uses __station_connect_network incorrectly since it
does not (and cannot) change the state after calling. The only
way to connect with a state change is via station_connect_network
which requires a DBus method that triggered the connection; DPP
does not have this due to its potentially long run time.
To support DPP there are a few options:
1. Pass a state into __station_connect_network (this patch)
2. Support a NULL DBus message in station_connect_network. This
would require several NULL checks and adding all that to only
support DPP just didn't feel right.
3. A 3rd connect API in station which wraps
__station_connect_network and changes the state. And again, an
entirely new API for only DPP felt wrong (I guess we did this
for network_autoconnect though...)
Its about 50/50 between call sites that changed state after calling
and those that do not. Changing the state inside
__station_connect_network felt useful enough to cover the cases that
could benefit and the remaining cases could handle it easily enough:
- network_autoconnect(), and the state is changed by station after
calling so it more or less follows the same pattern just routes
through network. This will now pass the CONNECTING_AUTO state
from within network vs station.
- The disconnect/reconnect path. Here the state is changed to
ROAMING prior in order to avoid multiple state changes. Knowing
this the same ROAMING state can be passed which won't trigger a
state change.
- Retrying after a failed BSS. The state changes on the first call
then remains the same for each connection attempt. To support this
the current station->state is passed to avoid a state change.
Until now IWD only supported enrollees as responders (configurators
could do both). For PKEX it makes sense for the enrollee to be the
initiator because configurators in the area are already on their
operating channel and going off is inefficient. For PKEX, whoever
initiates also initiates authentication so for this reason the
authentication path is being opened up to allow enrollees to
initiate.
The check for the header was incorrect according to the spec.
Table 58 indicates that the "Query Response Info" should be set
to 0x00 for the configuration request. The frame handler was
expecting 0x7f which is the value for the config response frame.
Unfortunately wpa_supplicant also gets this wrong and uses 0x7f
in all cases which is likely why this value was set incorrectly
in IWD. The issue is that IWD's config request is correct which
means IWD<->IWD configuration is broken. (and wpa_supplicant as
a configurator likely doesn't validate the config request).
Fix this by checking both 0x7f and 0x00 to handle both
supplicants.
Stopping periodic scans and not restarting them prevents autoconnect
from working again if DPP (or the post-DPP connect) fails. Since
the DPP offchannel work is at a higher priority than scanning (and
since new offchannels are queue'd before canceling) there is no risk
of a scan happening during DPP so its safe to leave periodic scans
running.
The packet loss handler puts a higher priority on roaming compared
to the low signal roam path. This is generally beneficial since this
event usually indicates some problem with the BSS and generally is
an indicator that a disconnect will follow sometime soon.
But by immediately issuing a scan we run the risk of causing many
successive scans if more packet loss events arrive following
the roam scans (and if no candidates are found). Logs provided
further.
To help with this handle the first event with priority and
immediately issue a roam scan. If another event comes in within a
certain timeframe (2 seconds) don't immediately scan, but instead
rearm the roam timer instead of issuing a scan. This also handles
the case of a low signal roam scan followed by a packet loss
event. Delaying the roam will at least provide some time for packets
to get out in between roam scans.
Logs were snipped to be less verbose, but this cycled happened
5 times prior. In total 7 scans were issued in 5 seconds which may
very well have been the reason for the local disconnect:
Oct 27 16:23:46 src/station.c:station_roam_failed() 9
Oct 27 16:23:46 src/wiphy.c:wiphy_radio_work_done() Work item 29 done
Oct 27 16:23:47 src/netdev.c:netdev_mlme_notify() MLME notification Notify CQM(64)
Oct 27 16:23:47 src/station.c:station_packets_lost() Packets lost event: 10
Oct 27 16:23:47 src/station.c:station_roam_scan() ifindex: 9
Oct 27 16:23:47 src/wiphy.c:wiphy_radio_work_insert() Inserting work item 30
Oct 27 16:23:47 src/wiphy.c:wiphy_radio_work_next() Starting work item 30
Oct 27 16:23:47 src/station.c:station_start_roam() Using cached neighbor report for roam
Oct 27 16:23:47 src/scan.c:scan_notify() Scan notification Trigger Scan(33)
Oct 27 16:23:47 src/scan.c:scan_request_triggered() Active scan triggered for wdev a
Oct 27 16:23:47 src/scan.c:scan_notify() Scan notification New Scan Results(34)
Oct 27 16:23:47 src/netdev.c:netdev_link_notify() event 16 on ifindex 9
... scan results ...
Oct 27 16:23:47 src/station.c:station_roam_failed() 9
Oct 27 16:23:47 src/wiphy.c:wiphy_radio_work_done() Work item 30 done
Oct 27 16:23:47 src/netdev.c:netdev_mlme_notify() MLME notification Notify CQM(64)
Oct 27 16:23:47 src/station.c:station_packets_lost() Packets lost event: 10
Oct 27 16:23:47 src/station.c:station_roam_scan() ifindex: 9
Oct 27 16:23:47 src/wiphy.c:wiphy_radio_work_insert() Inserting work item 31
Oct 27 16:23:47 src/wiphy.c:wiphy_radio_work_next() Starting work item 31
Oct 27 16:23:47 src/station.c:station_start_roam() Using cached neighbor report for roam
Oct 27 16:23:47 src/scan.c:scan_notify() Scan notification Trigger Scan(33)
Oct 27 16:23:47 src/scan.c:scan_request_triggered() Active scan triggered for wdev a
Oct 27 16:23:48 src/scan.c:scan_notify() Scan notification New Scan Results(34)
Oct 27 16:23:48 src/netdev.c:netdev_link_notify() event 16 on ifindex 9
... scan results ...
Oct 27 16:23:48 src/station.c:station_roam_failed() 9
Oct 27 16:23:48 src/wiphy.c:wiphy_radio_work_done() Work item 31 done
Oct 27 16:23:48 src/netdev.c:netdev_mlme_notify() MLME notification Notify CQM(64)
Oct 27 16:23:48 src/station.c:station_packets_lost() Packets lost event: 10
Oct 27 16:23:48 src/station.c:station_roam_scan() ifindex: 9
Oct 27 16:23:48 src/wiphy.c:wiphy_radio_work_insert() Inserting work item 32
Oct 27 16:23:48 src/wiphy.c:wiphy_radio_work_next() Starting work item 32
Oct 27 16:23:48 src/station.c:station_start_roam() Using cached neighbor report for roam
Oct 27 16:23:48 src/scan.c:scan_notify() Scan notification Trigger Scan(33)
Oct 27 16:23:48 src/scan.c:scan_request_triggered() Active scan triggered for wdev a
Oct 27 16:23:49 src/netdev.c:netdev_link_notify() event 16 on ifindex 9
Oct 27 16:23:49 src/netdev.c:netdev_mlme_notify() MLME notification Del Station(20)
Oct 27 16:23:49 src/netdev.c:netdev_mlme_notify() MLME notification Deauthenticate(39)
Oct 27 16:23:49 src/netdev.c:netdev_deauthenticate_event()
Oct 27 16:23:49 src/netdev.c:netdev_mlme_notify() MLME notification Disconnect(48)
Oct 27 16:23:49 src/netdev.c:netdev_disconnect_event()
Oct 27 16:23:49 Received Deauthentication event, reason: 4, from_ap: false
Include a specific timeout value so different protocols can specify
different timeouts. For example once the authentication timeout
should not take very long (even 10 seconds seems excessive) but
adding PKEX may warrant longer timeouts.
For example discovering a configurator IWD may want to wait several
minutes before ending the discovery. Similarly running PKEX as a
configurator we should put a hard limit on the time, but again
minutes rather than 10 seconds.
The memcpy in HEX2BUF was copying the length of the buffer that was
passed in, not the actual length of the converted hexstring. This
test was segfaulting in the Alpine CI which uses clang/musl.
Its been seen (so far only in mac80211_hwsim + UML) where an
offchannel requests ACK comes after the ROC started event. This
causes the ROC started event to never call back to notify since
info->roc_cookie is unset and it appears to be coming from an
external process.
We can detect this situation in the ROC notify event by checking
if there is a pending ROC command and if info->roc_cookie does
not match. This can also be true for an external event so we just
set a new "early_cookie" member and return.
Then, when the ACK comes in for the ROC request, we can validate
if the prior event was associated with IWD or some external
process. If it was from IWD call the started callback, otherwise
the ROC notify event should come later and handled under the
normal logic where the cookies match.
Instead of looking up by wdev, lookup by the ID itself. We
shouldn't ever have more than one info per wdev in the queue but
looking up the _exact_ info structure doesn't hurt in case things
change in the future.
If netconfig is canceled before completion (when roaming) the
settings are freed and never loaded again once netconfig is started
post-roam. Now after a roam make sure to re-load the settings and
start netconfig.
Commit 23f0f5717c did not correctly handle the reassociation
case where the state is set from within station_try_next_transition.
If IWD reassociates netconfig will get reset and DHCP will need to
be done over again after the roam. Instead get the state ahead of
station_try_next_transition.
Fixes: 23f0f5717c ("station: allow roaming before netconfig finishes")
When using mutual authentication an additional value needs to
be hashed when deriving i/r_auth values. A NULL value indicates
no mutual authentication (zero length iovec is passed to hash).
DPP configurators are running the majority of the protocol on the
current operating channel, meaning no ROC work. The retry logic
was bailing out if !dpp->roc_started with the assumption that DPP
was in between requesting offchannel work and it actually starting.
For configurators, this may not be the case. The offchannel ID also
needs to be checked, and if no work is scheduled we can send the
frame.
The prf_plus API was a bit restrictive because it only took a
string label which isn't compatible with some specs (e.g. DPP
inputs to HKDF-Expand). In addition it took additional label
aruments which were appended to the HMAC call (and the
non-intuitive '\0' if there were extra arguments).
Instead the label argument has been removed and callers can pass
it in through va_args. This also lets the caller decided the length
and can include the '\0' or not, dependent on the spec the caller
is following.