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).
REKEY_GTK kicks off the GTK only handshake where REKEY_PTK does
both (via the 4-way). The way this utility was written was causing
hostapd some major issues since both REKEY_GTK and REKEY_PTK was
used.
Instead if address is set only do REKEY_PTK. This will also rekey
the GTK via the 4-way handshake.
If no address is set do REKEY_GTK which will only rekey the GTK.
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.
The FT-over-DS test was allowed to fail as it stood. If FT-over-DS
failed it would just do a normal over-Air transition which satisfied
all the checks. To prevent this Authenticate frames are blocked after
the initial connection so if FT-over-DS fails there is no other way
to roam.
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.
