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()
This removes the need for duplicate code in AP/netdev for issuing
a DEL_STATION command. Now AP can issue a DEL_STATION with
netdev_del_station, and specify to either disassociate or deauth
depending on state.
If netdev fails to set the keys, there was no way for device/ap to
know. A new handshake event was added for this. The key setting
failure function was also fixed to support both AP/station iftypes.
It will now automatically send either a disconnect or del_station
depending on the interface type.
In similar manner, netdev_handshake_failed was also modified to
support both AP/station iftypes. Now, any handshake event listeners
should call netdev_handshake_failed upon a handshake failure
event, including AP.
Right now iwd uses Control Port over NL80211 feature if the kernel /
driver supports it. On some kernels this feature is still buggy, so add
an iwd.conf entry to allow the user to override id.
For now the default is to disable this feature until it is more stable.
These checks allow both a station and authenticator to use
the same netdev key install functions. For NEW_KEY and
SET_STATION, the iftype is checked and either handshake->aa
or ->spa is used as the station address for the KEY/STATION
commands. Also, in the failure cases, a disconnect command
is issued only if the iftype is station as this doesn't
apply to AP.
Handshake related netdev events were removed in favor of
handshake events. Now events will be emitted on the handshake
object related to the 4-way handshake and key settings. Events
are:
HANDSHAKE_EVENT_STARTED
HANDSHAKE_EVENT_SETTING_KEYS
HANDSHAKE_EVENT_COMPLETE
HANDSHAKE_EVENT_FAILED
Right now, since netdev only operates in station mode, nothing
listens for COMPLETE/FAILED, as device/wsc gets notified by the
connect_cb when the connection was successful. The COMPLETE/
FAILED were added in preperation for AP moving into eapol/netdev.
When a wifi interface is added/removed to/from a bridge, a
RTM_NEW/DELLINK event is issued. This is the same event used to signal
when an interface is created/deleted.
For this reason the event generated by the bridge code has to be
properly distinguished and handled accordingly. Failing to do so will
result in inconsistencies in iwd which will think an interface has been
deleted when it was actually not.
Detect incoming NEW/DELLINK bridge events and reacts accordingly. For
now, this simply means printing a simple message, as there is no
special logic in iwd for this yet.
If Control Port over NL80211 is not supported, open up a PAE socket and
stuff it into an l_io on the netdev object. Install a read handler on
the l_io and call __eapol_rx_packet as needed.
With the introduction of Control Port Over NL80211 feature, the
transport details need to be moved out of eapol and into netdev.c.
Whether a given WiFi hardware supports transfer of Control Port packets
over NL80211 is Wiphy and kernel version related, so the transport
decisions need to be made elsewhere.
handshake_state_install_ptk triggers a call to
netdev_set_pairwise_key_cb which calls netdev_connect_ok, so don't call
netdev_connect_ok after handshake_state_install_ptk. This doesn't fix
any specific problem though.
SA Query procedure is used when an unprotected disassociate frame
is received (with frame protection enabled). There are two code
paths that can occur when this disassociate frame is received:
1. Send out SA Query and receive a response from the AP within a
timeout. This means that the disassociate frame was not sent
from the AP and can be ignored.
2. Send out SA Query and receive no response. In this case it is
assumed that the AP went down ungracefully and is now back up.
Since frame protection is enabled, you must re-associate with
the AP.
When the 4-Way Handshake is done eapol.c calls netdev_set_tk, then
optionally netdev_set_gtk and netdev_set_igtk. To support the no group
key option send the final SET STATION enabling the controlled port
inside the callback for the netdev_set_tk operation which always means
the end of a 4-Way Handshake rather than in the netdev_set_gtk callback.
The spec says exactly that the controlled port is enabled at the end of
the 4-Way Handshake.
The netlink operations will still be queued in the same order because
the netdev_set_tk/netdev_set_gtk/netdev_set_igtk calls happen in one
main loop iteration but even if the order changed it wouldn't matter.
On failure of any of the three operations netdev_setting_keys_failed
gets called and the remaining operations are cancelled.
The l_queue_find() to find other watches matching the new prefix
needs to be before the watchlist_link(), otherwise the prefix will
match itself and "registered" is always true.
Denis Kenzior