ELL ECC supports group 20 (P384) so OWE can also support it. This also
adds group negotiation, where OWE can choose a different group than the
default if the AP requests it.
A check needed to be added in netdev in order for the negotiation to work.
The RFC says that if a group is not supported association should be rejected
with code 77 (unsupported finite cyclic group) and association should be
started again. This rejection was causing a connect event to be emitted by
the kernel (in addition to an associate event) which would result in netdev
terminating the connection, which we didn't want. Since OWE receives the
rejected associate event it can intelligently decide whether it really wants
to terminate (out of supported groups) or try the next available group.
This also utilizes the new MIC/KEK/KCK length changes, since OWE dictates
the lengths of those keys.
Make sure we don't pass NULLs to memcmp or l_memdup when the prefix
buffer is NULL. There's no point having callers pass dummy buffers if
they need to watch frames independent of the frame data.
The changes to station.c are minor. Specifically,
station_build_handshake_rsn was modified to always build up the RSN
information, not just for SECURITY_8021X and SECURITY_PSK. This is
because OWE needs this RSN information, even though it is still
SECURITY_NONE. Since "regular" open networks don't need this, a check
was added (security == NONE && akm != OWE) which skips the RSN
building.
netdev.c needed to be changed in nearly the same manor as it was for
SAE. When connecting, we check if the AKM is for OWE, and if so create
a new OWE SM and start it. OWE handles all the ECDH, and netdev handles
sending CMD_AUTHENTICATE and CMD_ASSOCIATE when triggered by OWE. The
incoming authenticate/associate events just get forwarded to OWE as they
do with SAE.
Adhoc was not waiting for BOTH handshakes to complete before adding the
new peer to the ConnectedPeers property. Actually waiting for the gtk/igtk
(in a previous commit) helps with this, but adhoc also needed to keep track
of which handshakes had completed, and only add the peer once BOTH were done.
This required a small change in netdev, where we memcmp the addresses from
both handshakes and only set the PTK on one.
Currently, netdev triggers the HANDSHAKE_COMPLETE event after completing
the SET_STATION (after setting the pairwise key). Depending on the timing
this may happen before the GTK/IGTK are set which will result in group
traffic not working initially (the GTK/IGTK would still get set, but group
traffic would not work immediately after DBus said you were connected, this
mainly poses a problem with autotests).
In order to fix this, several flags were added in netdev_handshake_state:
ptk_installed, gtk_installed, igtk_installed, and completed. Each of these
flags are set true when their respective keys are set, and in each key
callback we try to trigger the handshake complete event (assuming all the
flags are true). Initially the gtk/igtk flags are set to true, for reasons
explained below.
In the WPA2 case, all the key setter functions are called sequentially from
eapol. With this change, the PTK is now set AFTER the gtk/igtk. This is
because the gtk/igtk are optional and only set if group traffic is allowed.
If the gtk/igtk are not used, we set the PTK and can immediately trigger the
handshake complete event (since gtk_installed/igtk_installed are initialized
as true). When the gtk/igtk are being set, we immediately set their flags to
false and wait for their callbacks in addition to the PTK callback. Doing it
this way handles both group traffic and non group traffic paths.
WPA1 throws a wrench into this since the group keys are obtained in a
separate handshake. For this case a new flag was added to the handshake_state,
'wait_for_gtk'. This allows netdev to set the PTK after the initial 4-way,
but still wait for the gtk/igtk setters to get called before triggering the
handshake complete event. As a precaution, netdev sets a timeout that will
trigger if the gtk/igtk setters are never called. In this case we can still
complete the connection, but print a warning that group traffic will not be
allowed.
==1628== Invalid read of size 1
==1628== at 0x405E71: hardware_rekey_cb (netdev.c:1381)
==1628== by 0x444E5B: process_unicast (genl.c:415)
==1628== by 0x444E5B: received_data (genl.c:534)
==1628== by 0x442032: io_callback (io.c:126)
==1628== by 0x4414CD: l_main_iterate (main.c:387)
==1628== by 0x44158B: l_main_run (main.c:434)
==1628== by 0x403775: main (main.c:489)
==1628== Address 0x5475208 is 312 bytes inside a block of size 320 free'd
==1628== at 0x4C2ED18: free (vg_replace_malloc.c:530)
==1628== by 0x43D94D: l_queue_clear (queue.c:107)
==1628== by 0x43D998: l_queue_destroy (queue.c:82)
==1628== by 0x40B431: netdev_shutdown (netdev.c:4765)
==1628== by 0x403B17: iwd_shutdown (main.c:81)
==1628== by 0x4419D2: signal_callback (signal.c:82)
==1628== by 0x4414CD: l_main_iterate (main.c:387)
==1628== by 0x44158B: l_main_run (main.c:434)
==1628== by 0x403775: main (main.c:489)
==1628== Block was alloc'd at
==1628== at 0x4C2DB6B: malloc (vg_replace_malloc.c:299)
==1628== by 0x43CA4D: l_malloc (util.c:62)
==1628== by 0x40A853: netdev_create_from_genl (netdev.c:4517)
==1628== by 0x444E5B: process_unicast (genl.c:415)
==1628== by 0x444E5B: received_data (genl.c:534)
==1628== by 0x442032: io_callback (io.c:126)
==1628== by 0x4414CD: l_main_iterate (main.c:387)
==1628== by 0x44158B: l_main_run (main.c:434)
==1628== by 0x403775: main (main.c:489)
Netdev/AP share several NL80211 commands and each has their own
builder API's. These were moved into a common file nl80211_util.[ch].
A helper was added to AP for building NEW_STATION to make the associate
callback look cleaner (rather than manually building NEW_STATION).
Check that netdev->device is not NULL before doing device_remove()
(which would crash) and emitting NETDEV_WATCH_EVENT_DEL. It may be
NULL if the initial RTM_SETLINK has failed to bring device UP.
In netdev_set_powered also check that no NL80211_CMD_SET_INTERFACE is in
progress because once it returned we would overwrite
netdev->set_powered_cmd_id (could also add a check there but it seems
more logical to just disallow Powered property changes while Mode is
being changed, since we also disallow Mode changes while Powered is
being changed.)
When we detect a new device we either bring it down and then up or only
up. The IFF_UP flag in netdev->ifi_flags is updated before that, then
we send the two rtnl commands and then fire the NETDEV_WATCH_EVENT_NEW
event if either the bring up succeeded or -ERFKILL was returned, so the
device may either be UP or DOWN at that point.
It seems that a RTNL NEWLINK notification is usually received before
the RTNL command callback but I don't think this is guaranteed so update
the IFF_UP flag in the callbacks so that the NETDEV_WATCH_EVENT_NEW
handlers can reliably use netdev_get_is_up()
The NL80211_ATTR_KEY_DEFAULT_TYPES attribute is only parsed by the
kernel if either NL80211_ATTR_KEY_DEFAULT or
NL80211_ATTR_KEY_DEFAULT_MGMT are also present, however these are only
used with NL80211_CMD_SET_KEY and ignored for NEW_KEY. As far as I
understand the default key concept only makes sense for a Tx key because
on Rx all keys can be tried, so we don't need this for client mode. The
kernel decides whether the NEW_KEY is for unicast or multicast based on
whether NL80211_ATTR_KEY_MAC was supplied.
Boiled down, FT over SAE is no different than FT over PSK, apart from
the different AKM suite. The bulk of this change fixes the current
netdev/station logic related to SAE by rebuilding the RSNE and adding
the MDE if present in the handshake to match what the PSK logic does.
A common function was introduced into station which will rebuild the
handshake rsne's for a target network. This is used for both new
network connections as well as fast transitions.
To prepare for FT over SAE, several case/if statements needed to include
IE_RSN_AKM_SUITE_FT_OVER_SAE. Also a new macro was introduced to remove
duplicate if statement code checking for both FT_OVER_SAE and SAE AKM's.
To avoid confusion in case of an authenticator side handshake_state
structure and eapol_sm structure, rename own_ie to supplicant_ie and
ap_ie to authenticator_ie. Also rename
handshake_state_set_{own,ap}_{rsn,wpa} and fix when we call
handshake_state_setup_own_ciphers. As a result
handshake_state_set_authenticator, if needed, should be called before
handshake_state_set_{own,ap}_{rsn,wpa}.
There was somewhat overlapping functionality in the device_watch
infrastructure as well as the netdev_event_watch. This commit combines
the two into a single watch based on the netdev object and cleans up the
various interface additions / removals.
With this commit the interfaces are created when the netdev/device is
switched to Powered=True state AND when the netdev iftype is also in the
correct state for that interface. If the device is brought down, then
all interfaces except the .Device interface are removed.
This will make it easy to implement Device.Mode property properly since
most nl80211 devices need to be brought into Powered=False state prior
to switching the iftype.
The way that netdev_set_linkmode_and_operstate was used resulted in
potential crashes when the netdev was destroyed. This is because netdev
was given as data to l_netlink_send and could be destroyed between the
time of the call and the callback. Since the result of calls to
netdev_set_linkmode_and_operstate is inconsequential, it isn't really
worthwhile tracking these calls in order to cancel them.
This patch simplies the handling of these rtnl calls, makes sure that
netdev isn't passed as user data and rewrites the
netdev_set_linkmode_and_operstate signature to be more consistent with
rtnl_set_powered.
Since all netdevs share the rtnl l_netlink object, it was possible for
netdevs to be destroyed with outstanding commands still executing on the
rtnl object. This can lead to crashes and other nasty situations.
This patch makes sure that Powered requests are always tracked via
set_powered_cmd_id and the request is canceled when netdev is destroyed.
This also implies that netdev_set_powered can now return an -EBUSY error
in case a request is already outstanding.
This removes the authenticator bit in eapol_sm as well as unifies
eapol_register_authenticator and eapol_register. Taking advantage
of the handshake state authenticator bit we no longer have a need
for 2 separate register functions.
ap, and adhoc were also updated to set the authenticator bit in
the handshake and only use eapol_register to register their sm's.
netdev was updated to use the authenticator bit when choosing the
correct key address for adhoc.
In order to plug SAE into the existing connect mechanism the actual
CMD_CONNECT message is never sent, rather sae_register takes care
of sending out CMD_AUTHENTICATE. This required some shuffling of
code in order to handle both eapol and sae. In the case of non-SAE
authentication everything behaves as it did before. When using SAE
an sae_sm is created when a connection is attempted but the eapol_sm
is not. After SAE succeeds it will start association and then create
the eapol_sm and start the 4-way handshake.
This change also adds the handshake SAE events to device and
initializes SAE in main.
Our logic would set CONTROL_PORT_OVER_NL80211 even in cases where
CONTROL_PORT wasn't used (e.g. for open networks). While the kernel
ignored this attribute in this case, it is nicer to set this only if
CONTROL_PORT is intended to be used.
SAE will require some of the same CMD_ASSOCIATE building code that
FT currently uses. This breaks out the common code from FT into
netdev_build_cmd_associate_common.
These will issue a JOIN/LEAVE_IBSS to the kernel. There is
a TODO regarding network configuration. For now, only the
SSID is configurable. This configuration is also required
for AP, but needs to be thought out. Since the current
AP Dbus API has nothing related to configuration items
such as freq/channel or RSN elements they are hard coded,
and will be for Ad-Hoc as well (for now).
Now that the device mode can be changed, netdev must check that
the iftype is correct before starting a connection or disconnecting.
netdev_connect, netdev_connect_wsc, and netdev_disconnect now check
that the iftype is station before continuing.
With the introduction of Ad-Hoc, its not as simple as choosing
aa/spa addresses when setting the keys. Since Ad-Hoc acts as
both the authenticator and supplicant we must check how the netdev
address relates to the particular handshake object as well as
choose the correct key depending on the value of the AA/SPA address.
802.11 states that the higher of the two addresses is to be used
to set the key for the Ad-Hoc connection.
A simple helper was added to choose the correct addressed based on
netdev type and handshake state. netdev_set_tk also checks that
aa > spa in the handshake object when in Ad-Hoc mode. If this is
true then the keys from that handshake are used, otherwise return
and the other handshake key will be used (aa will be > spa).
The station/ap mode behaves exactly the same as before.
For Ad-Hoc networks, the kernel takes care of auth/assoc
and issues a NEW_STATION event when that is complete. This
provides a way to notify when NEW_STATION events occur as
well as forward the MAC of the station to Ad-Hoc.
The two new API's added:
- netdev_station_watch_add()
- netdev_station_watch_remove()
James Prestwood