In order to support fullmac drivers the PMKSA entries must be added
and removed from the kernel. To accomplish this a set of driver
callbacks will be added to the PMKSA module. In addition a new
pmksa_cache_free API will be added whos only purpose is to handle
the removal from the kernel.
The iwd_notice function was more meant for special purpose events
not general debug prints. For these error conditions we should be
using l_warn. For the informational "External Auth to SSID" log
we already print this information when connecting from station. In
addition there are logs when performing external auth so it should
be very obvious external auth is being used without this log.
The netdev frame watches got cleaned up upon the interface going down
which works if the interface is simply being toggled but when IWD
shuts down it first shuts down the interface, then immediately frees
netdev. If a watched frame arrives immediately after that before the
interface shutdown callback it will reference netdev, which has been
freed.
Fix this by clearing out the frame watches in netdev_free.
==147== Invalid read of size 8
==147== at 0x408ADB: netdev_neighbor_report_frame_event (netdev.c:4772)
==147== by 0x467C75: frame_watch_unicast_notify (frame-xchg.c:234)
==147== by 0x4E28F8: __notifylist_notify (notifylist.c:91)
==147== by 0x4E2D37: l_notifylist_notify_matches (notifylist.c:204)
==147== by 0x4A1388: process_unicast (genl.c:844)
==147== by 0x4A1388: received_data (genl.c:972)
==147== by 0x49D82F: io_callback (io.c:105)
==147== by 0x49C93C: l_main_iterate (main.c:461)
==147== by 0x49CA0B: l_main_run (main.c:508)
==147== by 0x49CA0B: l_main_run (main.c:490)
==147== by 0x49CC3F: l_main_run_with_signal (main.c:630)
==147== by 0x4049EC: main (main.c:614)
If an AP directed roam frame comes in while IWD is roaming its
still valuable to parse that frame and blacklist the BSS that
sent it.
This can happen most frequently during a roam scan while connected
to an overloaded BSS that is requesting IWD roams elsewhere.
If the BSS is requesting IWD roam elsewhere add this BSS to the
blacklist using BLACKLIST_REASON_ROAM_REQUESTED. This will lower
the chances of IWD roaming/connecting back to this BSS in the
future.
This then allows IWD to consider this blacklist state when picking
a roam candidate. Its undesireable to fully ban a roam blacklisted
BSS, so some additional sorting logic has been added. Prior to
comparing based on rank, BSS's will be sorted into two higher level
groups:
Above Threshold - BSS is above the RoamThreshold
Below Threshold - BSS is below the RoamThreshold
Within each of these groups the BSS may be roam blacklisted which
will position it at the bottom of the list within its respecitve
group.
This adds a new (less severe) blacklist reason as well as an option
to configure the timeout. This blacklist reason will be used in cases
where a BSS has requested IWD roam elsewhere. At that time a new
blacklist entry will be added which will be used along with some
other criteria to determine if IWD should connect/roam to that BSS
again.
Now that we have multiple blacklist reasons there may be situations
where a blacklist entry already exists but with a different reason.
This is going to be handled by the reason severity. Since we have
just two reasons we will treat a connection failure as most severe
and a roam requested as less severe. This leaves us with two
possible situations:
1. BSS is roam blacklisted, then gets connection blacklisted:
The reason will be "promoted" to connection blacklisted.
2. BSS is connection blacklisted, then gets roam blacklisted:
The blacklist request will be ignored
When pruning the list check_if_expired was comparing to the maximum
amount of time a BSS can be blacklisted, not if the current time had
exceeded the expirationt time. This results in blacklist entries
hanging around longer than they should, which would result in them
poentially being blacklisted even longer if there was another reason
to blacklist in the future.
Instead on prune check the actual expiration and remove the entry if
its expired. Doing this removes the need to check any of the times
in blacklist_contains_bss since prune will remove any expired entries
correctly.
To both prepare for some new blacklisting behavior and allow for
easier consolidation of the network-specific blacklist include a
reason enum for each entry. This allows IWD to differentiate
between multiple blacklist types. For now only the existing
"permanent" type is being added which prevents connections to that
BSS via autoconnect until it expires.
Allowing the timeout blacklist to be disabled has introduced a bug
where a failed connection will not result in the BSS list to be
traversed. This causes IWD to retry the same BSS over and over which
be either a) have some issue preventing a connection or b) may simply
be unreachable/out of range.
This is because IWD was inherently relying on the timeout blacklist
to flag BSS's on failures. With it disabled there was nothing to tell
network_bss_select that we should skip the BSS and it would return
the same BSS indefinitely.
To fix this some of the blacklisting logic was re-worked in station.
Now, a BSS will always get network blacklisted upon a failure. This
allows network.c to traverse to the next BSS upon failure.
For auth/assoc failures we will then only timeout blacklist under
certain conditions, i.e. the status code was not in the temporary
list.
Fixes: 77639d2d452e ("blacklist: allow configuration to disable the blacklist")
Certain use cases may not need or want this feature so allowing it to
be disabled is a much cleaner way than doing something like setting
the timeouts very low.
Now [Blacklist].InitialTimeout can be set to zero which will prevent
any blacklisting.
In addition some other small changes were added:
- Warn if the multiplier is 0, and set to 1 if so.
- Warn if the initial timeout exceeds the maximum timeout.
- Log if the blacklist is disabled
- Use L_USEC_PER_SEC instead of magic numbers.
SAE/WPA3 is completely broken on brcmfmac, at least without a custom
kernel patch which isn't included in many OS distributions. In order
to help with this add a driver quirk so devices with brcmfmac can
utilize WPA2 instead of WPA3 and at least connect to networks at
this capacity until the fix is more widely distributed.
Instead of just printing the PMKSA pointer separate this into two
separate debug messages, one for if the PMKSA exists and the other
if it does not. In addition print out the MAC of the AP so we have
a reference of which PMKSA this is.
With external auth there is no associate event meaning the auth proto
never gets freed, which prevents eapol from starting inside the
OCI callback. Check for this specific case and free the auth proto
after signaling that external auth has completed.
The ath10k driver has shown some performance issues, specifically
packet loss, when frame watches are registered with the multicast
RX flag set. This is relevant for DPP which registers for these
when DPP starts (if the driver supports it). This has only been
observed when there are large groups of clients all using the same
wifi channel so its unlikely to be much of an issue for those using
IWD/ath10k and DPP unless you run large deployments of clients.
But for large deployments with IWD/ath10k we need a way to disable
the multicast RX registrations. Now, with the addition of
wiphy_supports_multicast_rx we can both check that the driver
supports this as well as if its been disabled by the driver quirk.
This driver quirk and associated helper API lets other modules both
check if multicast RX is supported, and if its been disabled via
the driver quirk setting.
The actual connection piece of this is very minimal, and only
requires station to check if there is a PMKSA cached, and if so
include the PMKID in the RSNE. Netdev then takes care of the rest.
The remainder of this patch is the error handling if a PMKSA
connection fails with INVALID_PMKID. In this case IWD should retry
the same BSS without PMKSA.
An option was also added to disable PMKSA if a user wants to do
that. In theory PMKSA is actually less secure compared to SAE so
it could be something a user wants to disable. Going forward though
it will be enabled by default as its a requirement from the WiFi
alliance for WPA3 certification.
To prepare for PMKSA support station needs access to the handshake
object. This is because if PMKSA fails due to an expired/missing
PMKSA on the AP station should retry using the standard association.
This poses a problem currently because netdev frees the handshake
prior to calling the connect callback.
This was quite simple and only requiring caching the PMKSA after a
successful handshake, and using the correct authentication type
for connections if we have a prior PMKSA cached.
This is only being added for initial SAE associations for now since
this is where we gain the biggest improvement, in addition to the
requirement by the WiFi alliance to label products as "WPA3 capable"
This is needed in order to clear the PMKSA from the handshake state
without actually putting it back into the cache. This is something
that will be needed in case the AP rejects the association due to
an expired (or forgotten) PMKSA.
The majority of this patch was authored by Denis Kenzior, but
I have appended setting the PMK inside handshake_state_set_pmksa
as well as checking if the pmkid exists in
handshake_state_steal_pmkid.
Authored-by: Denis Kenzior <denkenz@gmail.com>
Authored-by: James Prestwood <prestwoj@gmail.com>
This adds a ref count to the handshake state object (as well as
ref/unref APIs). Currently IWD is careful to ensure that netdev
holds the root reference to the handshake state. Other modules do
track it themselves, but ensure that it doesn't get referenced
after netdev frees it.
Future work related to PMKSA will require that station holds a
references to the handshake state, specifically for retry logic,
after netdev is done with it so we need a way to delay the free
until station is also done.
The utilization rank factor already existed but was very rigid
and only checked a few values. This adds the (optional) ability
to start applying an exponentially decaying factor to both
utilization and station count after some threshold is reached.
This area needs to be re-worked in order to support very highly
loaded networks. If a network either doesn't support client
balancing or does it poorly its left up to the clients to choose
the best BSS possible given all the information available. In
these cases connecting to a highly loaded BSS may fail, or result
in a disconnect soon after connecting. In these cases its likely
better for IWD to choose a slightly lower RSSI/datarate BSS over
the conventionally 'best' BSS in order to aid in distributing
the network load.
The thresholds are currently optional and not enabled by default
but if set they behave as follows:
If the value is above the threshold it is mapped to an integer
between 0 and 30. (using a starting range of <value> - 255).
This integer is then used to index in the exponential decay table
to get a factor between 1 and 0. This factor is then applied to
the rank.
Note that as the value increases above the threshold the rank
will be increasingly effected, as is expected for an exponential
function. These option should be used with care as it may have
unintended consequences, especially with very high load networks.
i.e. you may see IWD roaming to BSS's with much lower signal if
there are high load BSS's nearby.
To maintain the existing behavior if there is no utilization
factor set in main.conf the legacy thresholds/factors will be
used.
This is copied from network.c that uses a static table to lookup
exponential decay values by index (generated from 1/pow(n, 0.3)).
network.c uses this for network ranking but it can be useful for
BSS ranking as well if you need to apply some exponential backoff
to a value.
This has been needed elsewhere but generally shortcuts could be
taken mapping with ranges starting/ending with zero. This is a
more general linear mapping utility to map values between any
two ranges.
gcc-15 switched to -std=c23 by default:
https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=55e3bd376b2214e200fa76d12b67ff259b06c212
As a result `iwd` fails the build as:
../src/crypto.c:1215:24: error: incompatible types when returning type '_Bool' but 'struct l_ecc_point *' was expected
1215 | return false;
| ^~~~~
Signed-off-by: Rudi Heitbaum <rudi@heitbaum.com>
After the band is established we check the e4 table for the channel
that matches. The problem here is we will end up checking all the
operating classes, even those that are not within the band that was
determined. This could result in false positives and return a
channel that doesn't make sense.
When the frequencies/channels were parsed there was no check that the
resulting band matched what was expected. Now, pass the band object
itself in which has the band set to what is expected.
If IPv6 is disabled or not supported at the kernel level writing the
sysfs settings will fail. A few of them had a support check but this
patch adds a supported bool to the remainder so we done get errors
like:
Unable to write drop_unsolicited_na to /proc/sys/net/ipv6/conf/wlan0/drop_unsolicited_na
Similar to several other modules DPP registers for its frame
watches on init then ignores anything is receives unless DPP
is actually running.
Due to some recent issues surrounding ath10k and multicast frames
it was discovered that simply registering for multicast RX frames
causes a significant performance impact depending on the current
channel load.
Regardless of the impact to a single driver, it is actually more
efficient to only register for the DPP frames when DPP starts
rather than when IWD initializes. This prevents any of the frames
from hitting userspace which would otherwise be ignored.
Using the frame-xchg group ID's we can only register for DPP
frames when needed, then close that group and the associated
frame watches.
