It was seen during testing that several offload-capable cards
were not including the OCI in the 4-way handshake. This made
any OCV capable AP unconnectable.
To be safe disable OCV on any cards that support offloading.
802.11 requires an STA initiate the SA Query procedure on channel
switch events. This patch refactors sending the SA Query into its
own routine and starts the procedure when the channel switch event
comes in.
In addition the OCI needs to be verified, so the channel info is
parsed and set into the handshakes chandef.
There are several events for channel switching, and nl80211cmd was
naming two of them "Channel Switch Notify". Change
CH_SWITCH_STARTED_NOTIFY to "Channel Switch Started Notify" to
distinguish the two events.
SA query is the final protocol that requires OCI inclusion and
verification. The OCI element is now included and verified in
both request and response frames as required by 802.11.
strcmp behavior is undefined if one of the parameters is NULL.
Server-id is a mandatory value and cannot be NULL. Gateway can be NULL
in DHCP, so check that explicitly.
Reported-by: Andrew Zaborowski <andrew.zaborowski@intel.com>
In certain situations, it is possible for us to know the MAC of the
default gateway when DHCP finishes. This is quite typical on many home
network and small network setups. It is thus possible to pre-populate
the ARP cache with the gateway MAC address to save an extra round trip
at connection time.
Another advantage is during roaming. After version 4.20, linux kernel
flushes ARP caches by default whenever netdev encounters a no carrier
condition (as is the case during roaming). This can prevent packets
from going out after a roam for a significant amount of time due to
lost/delayed ARP responses.
This implements the new handshake callback for setting a TK with
an extended key ID. The procedure is different from legacy zero
index TKs.
First the new TK is set as RX only. Then message 4 should be sent
out (so it uses the existing TK). This poses a slight issue with
PAE sockets since message order is not guaranteed. In this case
the 4th message is stored and sent after the new TK is installed.
Then the new TK is modified using SET_KEY to both send and
receive.
In the case of control port over NL80211 the above can be avoided
and we can simply install the new key, send message 4, and modify
the TK as TX + RX all in sequence, without waiting for any callbacks.
When UseDefaultInterface is set, iwd doesn't attempt to destroy and
recreate any default interfaces it detects. However, only a single
default interface was ever remembered & initialized. This is fine for
most cases since the kernel would typically only create a single netdev
by default.
However, some drivers can create multiple netdevs by default, if
configured to do so. Other usecases, such as tethering, can also
benefit if iwd initialized & managed all default netdevs that were
detected at iwd start time or device hotplug.
oci variable is always set during handshake_util_find_kde. Do not
initialize it unnecessarily to help the compiler / static analysis find
potential issues.
If OCI is not used, then the oci array is never initialized. Do not try
to include it in our GTK 2_of_2 message.
Fixes: ad4d639854 ("eapol: include OCI in GTK 2/2")
802.11 added Extended Key IDs which aim to solve the issue of PTK
key replacement during rekeys. Since swapping out the existing PTK
may result in data loss because there may be in flight packets still
using the old PTK.
Extended Key IDs use two key IDs for the PTK, which toggle between
0 and 1. During a rekey a new PTK is derived which uses the key ID
not already taken by the existing PTK. This new PTK is added as RX
only, then message 4/4 is sent. This ensure message 4 is encrypted
using the previous PTK. Once sent, the new PTK can be modified to
both RX and TX and the rekey is complete.
To handle this in eapol the extended key ID KDE is parsed which
gives us the new PTK key index. Using the new handshake callback
(handshake_state_set_ext_tk) the new TK is installed. The 4th
message is also included as an argument which is taken care of by
netdev (in case waiting for NEW_KEY is required due to PAE socekts).
This may not be required but setting the group key mode explicitly
to multicast makes things consistent, even if only for the benefit
of reading iwmon logs easier.
The procedure for setting extended key IDs is different from the
single PTK key. The key ID is toggled between 0 and 1 and the new
key is set as RX only, then set to RX/TX after message 4/4 goes
out.
Since netdev needs to set this new key before sending message 4,
eapol can include a built message which netdev will store if
required (i.e. using PAE).
ext_key_id_capable indicates the handshake has set the capability bit
in the RSN info. This will only be set if the AP also has the capability
set.
active_tk_index is the key index the AP chose in message 3. This is
now used for both legacy (always zero) and extended key IDs.
Move the reading of ControlPortOverNL80211 into wiphy itself and
renamed wiphy_control_port_capable to wiphy_control_port_enabled.
This makes things easier for any modules interested in control
port support since they will only have to check this one API rather
than read the settings and check capability.
Expose the Device Address property for each peer. The spec doesn't say
much about how permanent the address or the name are, although the
device address by definition lives longer than the interface addresses.
However the device address is defined to be unique and the name is not
so the address can be used to differentiate devices with identical name.
Being unique also may imply that it's assigned globally and thus
permanent.
Network Manager uses the P2P device address when saving connection
profiles (and will need it from the backend) and in this case it seems
better justified than using the name.
The address is already in the object path but the object path also
includes the local phy index which may change for no reason even when
the peer's address hasn't changed so the path is not useful for
remembering which device we've connected to before. Looking at only
parts of the path is considered wrong.
Some drivers might not actually support control port properly even if
advertised by mac80211. Introduce a new method to wiphy that will take
care of looking up any driver quirks that override the presence of
NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211
Make consecutive calls to netconfig_load_settings() memory-leak safe by
introducing a netconfig_free_settings convenience method. This method
will free any settings that are allocated as a result of
netconfig_load_settings() and will be called from netconfig_free() to
ensure that any settings are freed as a result of netconfig_destroy().
For symmetry with IPv4, save the command id for this netlink command so
we can later add logic to the callback as well as be able to cancel the
command. No functional change in this commit alone.
FT/FILS handle their own PMK derivation but rekeys still require
using the 4-way handshake. There is some ambiguity in the spec whether
or not the PMKID needs to be included in message 1/4 and it appears
that when rekeying after FT/FILS hostapd does not include a PMKID.
The handshake contains the current BSS's RSNE/WPA which may differ
from the FT-over-DS target. When verifying the target BSS's RSNE/WPA
IE needs to be checked, not the current BSS.
If the deauth path was triggered IWD would deauth but end up
calling the connect callback with whatever result netdev had
set, e.g. 'NETDEV_RESULT_OK'. This, of course, caused station
some confusion.
FT-over-DS cannot use OCV due to how the kernel works. This means
we could connect initially with OCVC set, but a FT-over-DS attempt
needs to unset OCVC. Set OCVC false when rebuilding the RSNE for
reassociation.
The FT-over-DS action stage builds an FT-Request which contains an
RSNE. Since FT-over-DS will not support OCV add a boolean to
ft_build_authenticate_ies so the OCVC bit can be disabled rather
than relying on the handshake setting.
This modifies the FT logic to fist call get_oci() before
reassociation. This allows the OCI to be included in reassociation
and in the 4-way handshake later on.
The code path for getting the OCI had to be slightly changed to
handle an OCI that is already set. First the handshake chandef is
NULL'ed out for any new connection. This prevents a stale OCI from
being used. Then some checks were added for this case in
netdev_connect_event and if chandef is already set, start the 4-way
handshake.
James Prestwood