All uses of frame-xchg were for action frames, and the frame type
was hard coded. Soon other frame types will be needed so the type
must now be specified in the frame_xchg_prefix structure.
This will make the debug API more robust as well as fix issues
certain drivers have when trying to roam. Some of these drivers
may flush scan results after CMD_CONNECT which results in -ENOENT
when trying to roam with CMD_AUTHENTICATE unless you rescan
explicitly.
Now this will be taken care of automatically and station will first
scan for the BSS (or full scan if not already in results) and
attempt to roam once the BSS is seen in a fresh scan.
The logic to replace the old BSS object was factored out into its
own function to be shared by the non-debug roam scan. It was also
simplified to just update the network since this will remove the
old BSS if it exists.
Add a second netconfig-commit backend which, if enabled, doesn't
directly send any of the network configuration to the kernel or system
files but delegates the operation to an interested client's D-Bus
method as described in doc/agent-api.txt. This backend is switched to
when a client registers a netconfig agent object and is swiched away
from when the client disconnects or unregisters the agent. Only one
netconfig agent can be registered any given time.
Add netconfig_event_handler() that responds to events emitted by
the l_netconfig object by calling netconfig_commit, tracking whether
we're connected for either address family and emitting
NETCONFIG_EVENT_CONNECTED or NETCONFIG_EVENT_FAILED as necessary.
NETCONFIG_EVENT_FAILED is a new event as until now failures would cause
the netconfig state machine to stop but no event emitted so that
station.c could take action. As before, these events are only
emitted based on the IPv4 configuration state, not IPv6.
Add netconfig-commit.c whose main method, netconfig_commit actually sets
the configuration obtained by l_netconfig to the system netdev,
specifically it sets local addresses on the interface, adds routes to the
routing table, sets DNS related data and may add entries to the neighbor
cache. netconfig-commit.c uses a backend-ops type structure to allow
for switching backends. In this commit there's only a default backend
that uses l_netconfig_rtnl_apply() and a struct resolve object to write
the configuration.
netconfig_gateway_to_arp is moved from netconfig.c to netconfig-commit.c
(and renamed.) The struct netconfig definition is moved to netconfig.h
so that both files can access the settings stored in the struct.
To avoid repeated lookups by ifindex, replace the ifindex member in
struct netconfig with a struct netdev pointer. A struct netconfig
always lives shorter than the struct netdev.
* make the error handling simpler,
* make error messages more consistent,
* validate address families,
* for IPv4 skip l_rtnl_address_set_noprefixroute()
as l_netconfig will do this internally as needed.
* for IPv6 set the default prefix length to 64 as that's going to be
used for the local prefix route's prefix length and is a more
practical value.
Drop all the struct netconfig members where we were keeping the parsed
netconfig settings and add a struct l_netconfig object. In
netconfig_load_settings load all of the settings once parsed directly
into the l_netconfig object. Only preserve the mdns configuration and
save some boolean values needed to properly handle static configuration
and FILS. Update functions to use the new set of struct netconfig
members.
These booleans mirroring the l_netconfig state could be replaced by
adding l_netconfig getters for settings which currently only have
setters.
In anticipation of switching to use the l_netconfig API, which
internally handles DHCPv4, DHCPv6, ACD, etc., drop pointers to
instances of l_dhcp_client, l_dhcp6_client and l_acd from struct
netconfig. Also drop all code used for handling events from these
APIs, including code to commit the received configurations to the
system. Committing the final settings to the system netdevs is going to
be handled by a new set of utilities in a new file.
The RRM module was blindly scanning using the requested
frequency which may or may not be possible given the hardware.
Instead check that the frequency will work and if not reject
the request.
This was reported by a user seeing the RRM scan fail which was
due to the AP requesting a scan on 5GHz when the adapter was
2.4GHz only.
Support for MAC address changes while powered was recently added to
mac80211. This avoids the need to power down the device which both
saves time as well as preserves any allowed frequencies which may
have been disabled if the device powered down.
The code path for changing the address was reused but now just the
'up' callback will be provided directly to l_rtnl_set_mac. Since
there aren't multiple stages of callbacks the rtnl_data structure
isn't strictly needed, but the code looks cleaner and more
consistent between the powered/non-powered code paths.
The comment/debug error print was also updated to be more general
between the two MAC change code paths.
Documentation for MulticastDNS setting suggests it should be part of the
main iwd configuration file. See man iwd.config. However, in reality
the setting was being pulled from the network provisioning file instead.
The latter actually makes more sense since systemd-resolved has its own
set of global defaults. Fix the documentation to reflect the actual
implementation.
netdev does not keep any pointers to struct scan_bss arguments that are
passed in. Make this explicitly clear by modifying the API definitions
and mark these as const.
This adds a new netdev event for packet loss notifications from
the kernel. Depending on the scenario a station may see packet
loss events without any other indications like low RSSI. In these
cases IWD should still roam since there is no data flowing.
Some APs use an older hostapd OWE implementation which incorrectly
derives the PTK. To work around this group 19 should be used for
these APs. If there is a failure (reason=2) and the AKM is OWE
set force default group into network and retry. If this has been
done already the behavior is no different and the BSS will be
blacklisted.
If a OWE network is buggy and requires the default group this info
needs to be stored in network in order for it to set this into the
handshake on future connect attempts.
This functionality works around the kernel's behavior of allowing
6GHz only after a regulatory domain update. If the regdom updates
scan.c needs to be aware in order to split up periodic scans, or
insert 6GHz frequencies into an ongoing periodic scan. Doing this
allows any 6GHz BSS's to show up in the scan results rather than
needing to issue an entirely new scan to see these BSS's.
The kernel's regulatory domain updates after some number of beacons
are processed. This triggers a regulatory domain update (and wiphy
dump) but only after a scan request. This means a full scan started
prior to the regdom being set will not include any 6Ghz BSS's even
if the regdom was unlocked during the scan.
This can be worked around by splitting up a large scan request into
multiple requests allowing one of the first commands to trigger a
regdom update. Once the regdom updates (and wiphy dumps) we are
hopefully still scanning and could append an additional request to
scan 6GHz.
In the case of an external scan, we won't have a scan_request object,
sr. Make sure to not crash in this case.
Also, since scan_request can no longer carry the frequency set in all
cases, add a new member to scan_results in order to do so.
Fixes: 27d8cf4ccc ("scan: track scanned frequencies for entire request")
The kernel handles setting the regulatory domain by receiving beacons
which set the country IE. Presumably since most regulatory domains
disallow 6GHz the default (world) domain also disables it. This means
until the country is set, 6GHz is disabled.
This poses a problem for IWD's quick scanning since it only scans a few
frequencies and this likely isn't enough beacons for the firmware to
update the country, leaving 6Ghz inaccessable to the user without manual
intervention (e.g. iw scan passive, or periodic scans by IWD).
To try and work around this limitation the quick scan logic has been
updated to check if a 6GHz AP has been connected to before and if that
frequency is disabled (but supported). If this is the case IWD will opt
for a full passive scan rather than scanning a limited set of
frequencies.
For whatever reason the kernel will send regdom updates even if
the regdom didn't change. This ends up causing wiphy to dump
which isn't needed since there should be no changes in disabled
frequencies.
Now the previous country is checked against the new one, and if
they match the wiphy is not dumped again.
A change in regulatory domain can result in frequencies being
enabled or disabled depending on the domain. This effects the
frequencies stored in wiphy which other modules depend on
such as scanning, offchannel work etc.
When the regulatory domain changes re-dump the wiphy in order
to update any frequency restrictions.
A helper to check whether the country code corresponds to a
real country, or some special code indicating the country isn't
yet set. For now, the special codes are OO (world roaming) and
XX (unknown entity).
Events to indicate when a regulatory domain wiphy dump has
started and ended. This is important because certain actions
such as scanning need to be delayed until the dump has finished.
The NEW_SCAN_RESULTS handling was written to only parse the frequency
list if there were no additional scan commands to send. This results in
the scan callback containing frequencies of only the last CMD_TRIGGER.
Until now this worked fine because a) the queue is only used for hidden
networks and b) frequencies were never defined by any callers scanning
for hidden networks (e.g. dbus/periodic scans).
Soon the scan command queue will be used to break up scan requests
meaning only the last scan request frequencies would be used in the
callback, breaking the logic in station.
Now the NEW_SCAN_RESULTS case will parse the frequencies for each scan
command rather than only the last.
The compiler treated the '1' as an int type which was not big enough
to hold a bit shift of 31:
runtime error: left shift of 1 by 31 places cannot be represented in
type 'int'
Instead of doing the iftype check manually, refactor
wiphy_get_supported_iftypes by adding a subroutine which just parses
out iftypes from a mask into a char** list. This removes the need to
case each iftype into a string.
Add extra logging around CQM events to help track wifi status. This is
useful for headless systems that can only be accessed over the network
and so information in the logs is invaluable for debugging outages.
Prior to this change, the only log for CQM messages is saying one was
received. This adds details to what attributes were set and the
associated data with them.
The signal strength log format was chosen to roughly match
wpa_supplicant's which looks like this:
CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-60 noise=-96 txrate=6000
Provides useful information on why a roam might have failed, such as
failing to find the BSS or the BSS being ranked lower, and why that
might be.
The output format is the same as station_add_seen_bss for consistency.
If a frequency is disabled IWD should keep track and disallow any
operations on that channel such as scanning. A new list has been added
which contains only disabled frequencies.
The scan_passive API wasn't using a const struct scan_freq_set as it
should be since it's not modifying the contents. Changing this to
const did require some additional changes like making the scan_parameters
'freqs' member const as well.
After changing scan_parameters, p2p needed updating since it was using
scan_parameters.freqs directly. This was changed to using a separate
scan_freq_set pointer, then setting to scan_parameters.freqs when needed.
Similar to the HT/VHT APIs, this estimates the data rate based on the
HE Capabilities element, in addition to our own capabilities. The
logic is much the same as HT/VHT. The major difference being that HE
uses several MCS tables depending on the channel width. Each width
MCS set is checked (if supported) and the highest estimated rate out
of all the MCS sets is used.
There appears to be a compiler bug with gcc 11.2 which thinks the vht_mcs_set
is a zero length array, and the memset of size 8 is out of bounds. This is only
seen once an element is added to 'struct band'.
In file included from /usr/include/string.h:519,
from src/wiphy.c:34:
In function ‘memset’,
inlined from ‘band_new_from_message’ at src/wiphy.c:1300:2,
inlined from ‘parse_supported_bands’ at src/wiphy.c:1423:11,
inlined from ‘wiphy_parse_attributes’ at src/wiphy.c:1596:5,
inlined from ‘wiphy_update_from_genl’ at src/wiphy.c:1773:2:
/usr/include/bits/string_fortified.h:59:10: error: ‘__builtin_memset’ offset [0, 7] is out of the bounds [0, 0] [-Werror=array-bounds]
59 | return __builtin___memset_chk (__dest, __ch, __len,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
60 | __glibc_objsize0 (__dest));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~
This increases the maximum data rate which now is possible with HE.
A few comments were also updated, one to include 6G when adjusting
the rank for >4000mhz, and the other fixing a typo.
This is a general way of finding the best MCS/NSS values which will work
for HT, VHT, and HE by passing in the max MCS values for each value which
the MCS map could contain (0, 1, or 2).
The HE capabilities information is contained in
NL80211_BAND_ATTR_IFTYPE_DATA where each entry is a set of attributes
which define the rules for one or more interface types. This patch
specifically parses the HE PHY and HE MCS data which will be used for
data rate estimation.
Since the set of info is per-iftype(s) the data is stored in a queue
where each entry contains the PHY/MCS info, and a uint32 bit mask where
each bit index signifies an interface type.
With the addition of HE, the print function for MCS sets needs to change
slightly. The maps themselves are the same format, but the values indicate
different MCS ranges. Now the three MCS max values are passed in.
This queue will hold iftype(s) specific data for HE capabilities. Since
the capabilities may differ per-iftype the data is stored as such. Iftypes
may share a configuration so the band_he_capabilities structure has a
mask for each iftype using that configuration.
Certain module dependencies were missing, which could cause a crash on
exit under (very unlikely) circumstances.
#0 l_queue_peek_head (queue=<optimized out>) at ../iwd-1.28/ell/queue.c:241
#1 0x0000aaaab752f2a0 in wiphy_radio_work_done (wiphy=0xaaaac3a129a0, id=6)
at ../iwd-1.28/src/wiphy.c:2013
#2 0x0000aaaab7523f50 in netdev_connect_free (netdev=netdev@entry=0xaaaac3a13db0)
at ../iwd-1.28/src/netdev.c:765
#3 0x0000aaaab7526208 in netdev_free (data=0xaaaac3a13db0) at ../iwd-1.28/src/netdev.c:909
#4 0x0000aaaab75a3924 in l_queue_clear (queue=queue@entry=0xaaaac3a0c800,
destroy=destroy@entry=0xaaaab7526190 <netdev_free>) at ../iwd-1.28/ell/queue.c:107
#5 0x0000aaaab75a3974 in l_queue_destroy (queue=0xaaaac3a0c800,
destroy=destroy@entry=0xaaaab7526190 <netdev_free>) at ../iwd-1.28/ell/queue.c:82
#6 0x0000aaaab7522050 in netdev_exit () at ../iwd-1.28/src/netdev.c:6653
#7 0x0000aaaab7579bb0 in iwd_modules_exit () at ../iwd-1.28/src/module.c:181
In this particular case, wiphy module was de-initialized prior to the
netdev module:
Jul 14 18:14:39 localhost iwd[2867]: ../iwd-1.28/src/wiphy.c:wiphy_free() Freeing wiphy phy0[0]
Jul 14 18:14:39 localhost iwd[2867]: ../iwd-1.28/src/netdev.c:netdev_free() Freeing netdev wlan0[45]
This fixes a crash associated with toggling the iftype to AP mode
then calling GetDiagnostics. The diagnostic interface is never
cleaned up when netdev goes down so DBus calls can still be made
which ends up crashing since the AP interface objects are no longer
valid.
Running the following iwctl commands in a script (once or twice)
triggers this crash reliably:
iwctl device wlp2s0 set-property Mode ap
iwctl device wlp2s0 set-property Mode station
iwctl device wlp2s0 set-property Mode ap
iwctl ap wlp2s0 start myssid secret123
iwctl ap wlp2s0 show
++++++++ backtrace ++++++++
0 0x7f8f1a8fe320 in /lib64/libc.so.6
1 0x451f35 in ap_dbus_get_diagnostics() at src/ap.c:4043
2 0x4cdf5a in _dbus_object_tree_dispatch() at ell/dbus-service.c:1815
3 0x4bffc7 in message_read_handler() at ell/dbus.c:285
4 0x4b5d7b in io_callback() at ell/io.c:120
5 0x4b489b in l_main_iterate() at ell/main.c:476
6 0x4b49a6 in l_main_run() at ell/main.c:519
7 0x4b4cd9 in l_main_run_with_signal() at ell/main.c:645
8 0x404f5b in main() at src/main.c:600
9 0x7f8f1a8e8b75 in /lib64/libc.so.6
+++++++++++++++++++++++++++
About a month ago hostapd was changed to set the secure bit on
eapol frames during rekeys (bc36991791). The spec is ambiguous
about this and has conflicting info depending on the sections you
read (12.7.2 vs 12.7.6). According to the hostapd commit log TGme
is trying to clarify this and wants to set secure=1 in the case
of rekeys. Because of this, IWD is completely broken with rekeys
since its disallows secure=1 on PTK 1/4 and 2/4.
Now, a bool is passed to the verify functions which signifies if
the PTK has been negotiated already. If secure differs from this
the key frame is not verified.
The man pages (iwd.network) have a section about how to name provisioning
files containing non-alphanumeric characters but not everyone reads the
entire man page.
Warning them that the provisioning file was not read and pointing to
'man iwd.network' should lead someone in the right direction.
EAP-Success might come in with an identifier that is incremented by 1
from the last Response packet. Since identifier field is a byte, the
value might overflow (from 255 -> 0.) This overflow isn't handled
properly resulting in EAP-Success/Failure packets with a 0 identifier
due to overflow being erroneously ignored. Fix that.
Most users of storage_network_open don't log errors when the function
returns a NULL and fall back to defaults (empty l_settings).
storage_network_open() itself only logs errors if the flie is encrypted.
Now also log an error when l_settings_load_from_file() fails to help track
down potential syntax errors.
Drop the wrong negation in the error check. Check that there are no extra
characters after prefix length suffix. Reset errno 0 before the strtoul
call, as recommended by the manpage.
This is actually a false positive only because
p2p_device_validate_conn_wfd bails out if the IE is NULL which
avoids using wfd_data_length. But its subtle and without inspecting
the code it does seem like the length could be used uninitialized.
src/p2p.c:940:7: error: variable 'wfd_data_len' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
if (dev->conn_own_wfd)
^~~~~~~~~~~~~~~~~
src/p2p.c:946:8: note: uninitialized use occurs here
wfd_data_len))
^~~~~~~~~~~~
src/p2p.c:940:3: note: remove the 'if' if its condition is always true
if (dev->conn_own_wfd)
^~~~~~~~~~~~~~~~~~~~~~
src/p2p.c:906:23: note: initialize the variable 'wfd_data_len' to silence this warning
ssize_t wfd_data_len;
^
= 0
On musl-gcc the compiler is giving a warning for igtk_key_index
and gtk_key_index being used uninitialized. This isn't possible
since they are only used if gtk/igtk are non-NULL so pragma to
ignore the warning.
src/fils.c: In function 'fils_rx_associate':
src/fils.c:580:17: error: 'igtk_key_index' may be used uninitialized
in this function [-Werror=maybe-uninitialized]
580 | handshake_state_install_igtk(fils->hs,
igtk_key_index,igtk + 6,
igtk_len - 6, igtk);
(same error for gtk_key_index)
For network configuration files the man pages (iwd.network) state
that [General].{AlwaysRandomizeAddress,AddressOverride} are only
used if main.conf has [General].AddressRandomization=network.
This actually was not being enforced and both iwd.network settings
were still taken into account regardless of what AddressRandomization
was set to (even disabled).
The handshake setup code now checks the AddressRandomization value
and if anything other than 'network' skips the randomization.
There were a few places in dpp/dpp-util which passed a single byte but
was being read in with va_arg(va, size_t). On some architectures this was
causing failures presumably from the compiler using an integer type
smaller than size_t. As we do elsewhere, cast to size_t to force the
compiler to pass a properly sized iteger to va_arg.
After one of the eap-tls-common-based methods succeeds keep the TLS
tunnel instance until the method is freed, rather than free it the
moment the method succeeds. This fixes repeated method runs where until
now each next run would attempt to create a new TLS tunnel instance
but would have no authentication data (CA certificate, client
certificate, private key and private key passphrase) since those are
were by the old l_tls object from the moment of the l_tls_set_auth_data()
call.
Use l_tls_reset() to reset the TLS state after method success, followed
by a new l_tls_start() when the reauthentication starts.
A user reported that IWD was failing to FT in some cases and this was
due to the AP setting the Retry bit in the frame type. This was
unexpected by IWD since it directly checks the frame type against
0x00b0 which does not account for any B8-B15 bits being set.
IWD doesn't need to verify the frame type field for a few reasons:
First mpdu_validate checks the management frame type, Second the kernel
checks prior to forwarding the event. Because of this the check was
removed completely.
Reported-By: Michael Johnson <mjohnson459@gmail.com>
station_signal_agent_notify() has been refactored so that its usage is
simpler. station_rssi_level_changed() has been replaced by an inlined
call to station_signal_agent_notify().
The call to netdev_rssi_level_init() in netdev_connect_common() is
currently a no-op, because netdev->connected has not yet been set at
this stage of the connection attempt. Because netdev_rssi_level_init()
is only used twice, it's been replaced by two inlined calls to
netdev_set_rssi_level_idx().
The SignalLevelAgent API is currently broken by the system bus's
security policy, which blocks iwd's outgoing method call messages. This
patch punches a hole for method calls on the
net.connman.iwd.SignalLevelAgent interface.
There may be situations where DNS information should not be set (for
example in auto-tests where the resolver daemon is not running) or if a
user wishes to ignore DNS information obtained.
Allows granularly specifying the DHCP logging level. This allows the
user to tailor the output to what they need. By default, always display
info, errors and warnings to match the rest of iwd.
Setting `IWD_DHCP_DEBUG` to "debug", "info", "warn", "error" will limit
the logging to that level or higher allowing the default logging
verbosity to be reduced.
Setting `IWD_DHCP_DEBUG` to "1" as per the current behavior will
continue to enable debug level logging.
After the initial handshake, once the TK has been installed, all frames
coming to the AP should be encrypted. However, it seems that some
kernel/driver combinations allow unencrypted EAPoL frames to be received
and forwarded to userspace. This can lead to various attacks.
Some drivers can report whether the EAPoL frame has been received
unencrypted. Use this information to drop unencrypted EAPoL frames
received after the initial handshake has been completed.
After the initial handshake, once the TK has been installed, all frames
coming from the AP should be encrypted. However, it seems that some
kernel/driver combinations allow unencrypted EAPoL frames to be received
and forwarded to userspace. This can lead to a denial-of-service attack
where receipt of an invalid, unencrypted EAP-Failure frame generated by
an adversary results in iwd terminating an ongoing connection.
Some drivers can report whether the EAPoL frame has been received
unencrypted. Use this information to drop unencrypted EAP frames
received after the initial handshake has been completed.
Reported-by: Domien Schepers <schepers.d@northeastern.edu>
After the initial handshake, once the TK has been installed, all frames
coming from the AP should be encrypted. However, it seems that some
kernel/driver combinations allow unencrypted EAPoL frames to be received
and forwarded to userspace. This can lead to a denial-of-service attack
where receipt of an invalid, unencrypted EAPoL 1/4 frame generated by an
adversary results in iwd terminating an ongoing connection.
Some drivers can report whether the EAPoL frame has been received
unencrypted. Use this information to drop unencrypted PTK 1/4 frames
received after the initial handshake has been completed.
Reported-by: Domien Schepers <schepers.d@northeastern.edu>
Do not fail an ongoing handshake when an invalid EAPoL frame is
received. Instead, follow the intent of 802.11-2020 section 12.7.2:
"EAPOL-Key frames containing invalid field values shall be silently
discarded."
This prevents a denial-of-service attack where receipt of an invalid,
unencrypted EAPoL 1/4 frame generated by an adversary results in iwd
terminating an ongoing connection.
Reported-by: Domien Schepers <schepers.d@northeastern.edu>
Periodic scan requests are meant to be performed with a lower priority
than normal scan requests. They're thus given a different priority when
inserting them into the wiphy work queue. Unfortunately, the priority
is not taken into account when they are inserted into the
sr->requests queue. This can result in the scanning code being confused
since it assumes the top of the queue is always the next scheduled or
currently ongoing scan. As a result any further wiphy_work might never be
started properly.
Apr 27 16:34:40 iwd[5117]: ../iwd-1.26/src/wiphy.c:wiphy_radio_work_insert() Inserting work item 3
Apr 27 16:34:40 iwd[5117]: ../iwd-1.26/src/wiphy.c:wiphy_radio_work_next() Starting work item 3
Apr 27 16:34:40 iwd[5117]: ../iwd-1.26/src/scan.c:scan_periodic_timeout() 1
Apr 27 16:34:40 iwd[5117]: ../iwd-1.26/src/wiphy.c:wiphy_radio_work_insert() Inserting work item 4
Apr 27 16:34:43 iwd[5117]: ../iwd-1.26/src/wiphy.c:wiphy_radio_work_insert() Inserting work item 5
Apr 27 16:34:43 iwd[5117]: ../iwd-1.26/src/wiphy.c:wiphy_radio_work_done() Work item 3 done
Apr 27 16:34:43 iwd[5117]: ../iwd-1.26/src/wiphy.c:wiphy_radio_work_next() Starting work item 5
Apr 27 16:34:43 iwd[5117]: ../iwd-1.26/src/scan.c:scan_notify() Scan notification Trigger Scan(33)
Apr 27 16:34:43 iwd[5117]: ../iwd-1.26/src/scan.c:scan_request_triggered() Passive scan triggered for wdev 1
Apr 27 16:34:43 iwd[5117]: ../iwd-1.26/src/scan.c:scan_periodic_triggered() Periodic scan triggered for wdev 1
In the above log, scan request 5 (triggered by dbus) is started before
scan request 4 (periodic scan). Yet the scanning code thinks scan
request 4 was triggered.
Fix this by using the wiphy_work priority to sort the sr->requests queue
so that the scans are ordered in the same manner.
Reported-by: Alvin Šipraga <ALSI@bang-olufsen.dk>
The upstream code immediately retransmitted any no-ACK frames.
This would work in cases where the peer wasn't actively switching
channels (e.g. the ACK was simply lost) but caused unintended
behavior in the case of a channel switch when the peer was not
listening.
If either IWD or the peer needed to switch channels based on the
authenticate request the response may end up not getting ACKed
because the peer is idle, or in the middle of the hardware changing
channels. IWD would get no-ACK and immediately send the frame again
and most likely the same behavior would result. This would very
quickly increment frame_retry past the maximum and DPP would fail.
Instead when no ACK is received wait 1 second before sending out
the next frame. This can re-use the existing frame_pending buffer
and the same logic for re-transmitting.
There is a potential corner case of an offchannel frame callback
being called after ROC has ended.
This could happen in theory if a received frame is queued right as
the ROC session expires. If the ROC cancel event makes it to user
space before the frame IWD will schedule another ROC then receive
the frame. This doesn't prevent IWD from sending out another
frame since OFFCHANNEL_TX_OK is used, but it will prevent IWD from
receiving a response frame since no dwell duration is used with DPP.
To handle this an roc_started bool was added to the dpp_sm which
tracks the ROC state. If dpp_send_frame is called when roc_started
is false the frame will be saved and sent out once the ROC session
is started again.
ConnectHiddenNetwork creates a temporary network object and initiates a
connection with it. If the connection fails (due to an incorrect
passphrase or other reasons), then this temporary object is destroyed.
Delay its destruction until network_disconnected() since
network_connect_failed is called too early. Also, re-order the sequence
in station_reset_connection_state() in order to avoid using the network
object after it has been freed by network_disconnected().
Fixes: 85d9d6461f ("network: Hide hidden networks on connection error")
station_hide_network will remove and free the network object, so calling
network_close_settings will result in a crash. Make sure this is done
prior to network object's destruction.
Fixes: 85d9d6461f ("network: Hide hidden networks on connection error")
If a user connection fails on a freshly scanned psk or open hidden
network, during passphrase request or after, it shall be removed from
the network list. Otherwise, it would be possible to directly connect
to that known network, which will appear as not hidden.
p2p_peer_update_existing may be called with a scan_bss struct built from
a Probe Request frame so it can't access bss->p2p_probe_resp_info even
if peer->bss was built from a Probe Response. Check the source frame
type of the scan_bss struct before updating the Device Address.
This fixes one timing issue that would make the autotest fail often.
Since l_malloc is used the frame contents are not zero'ed automatically
which could result in random bytes being present in the frame which were
expected to be zero. This poses a problem when calculating the MIC as the
crypto operations are done on the entire frame with the expectation of
the MIC being zero.
Fixes: 83212f9b23 ("eapol: change eapol_create_common to support FILS")
explicit_bzero is used in src/storage.c since commit
01cd858760 but src/missing.h is not
included, as a result build with uclibc fails on:
/home/buildroot/autobuild/instance-0/output-1/host/lib/gcc/powerpc-buildroot-linux-uclibc/10.3.0/../../../../powerpc-buildroot-linux-uclibc/bin/ld: src/storage.o: in function `storage_init':
storage.c:(.text+0x13a4): undefined reference to `explicit_bzero'
Fixes:
- http://autobuild.buildroot.org/results/2aff8d3d7c33c95e2c57f7c8a71e69939f0580a1
This is used to hold the current BSS frequency which will be
used after IWD receives a presence announcement. Since this was
not being set, the logic was always thinking there was a channel
mismatch (0 != current_freq) and attempting to go offchannel to
'0' which resulted in -EINVAL, and ultimately protocol termination.
The logic here assumed any BSS's in the roam scan were identical to
ones in station's bss_list with the same address. Usually this is true
but, for example, if the BSS changed frequency the one in station's
list is invalid.
Instead when a match is found remove the old BSS and re-insert the new
one.
With the addition of 6GHz '6000' is no longer the maximum frequency
that could be in .known_network.freq. For more robustness
band_freq_to_channel is used to validate the frequency.
Scanning while in AP mode is somewhat of an edge case, but it does
have some usefulness specifically with onboarding new devices, i.e.
a new device starts an AP, a station connects and provides the new
device with network credentials, the new device switches to station
mode and connects to the desired network.
In addition this could be used later for ACS (though this is a bit
overkill for IWD's access point needs).
Since AP performance is basically non-existant while scanning this
feature is meant to be used in a limited scope.
Two DBus API's were added which mirror the station interface: Scan and
GetOrderedNetworks.
Scan is no different than the station variant, and will perform an active
scan on all channels.
GetOrderedNetworks diverges from station and simply returns an array of
dictionaries containing basic information about networks:
{
Name: <ssid>
SignalStrength: <mBm>
Security: <psk, open, or 8021x>
}
Limitations:
- Hidden networks are not supported. This isn't really possible since
the SSID's are unknown from the AP perspective.
- Sharing scan results with station is not supported. This would be a
convenient improvement in the future with respect to onboarding new
devices. The scan could be performed in AP mode, then switch to
station and connect immediately without needing to rescan. A quick
hack could better this situation by not flushing scan results in
station (if the kernel retains these on an iftype change).
This was already implemented in station but with no dependency on
that module at all. AP will need this for a scanning API so its
being moved into scan.c.
The 802.11ax standards adds some restrictions for the 6GHz band. In short
stations must use SAE, OWE, or 8021x on this band and frame protection is
required.
All uses of this macro will work with a bitwise comparison which is
needed for 6GHz checks and somewhat more flexible since it can be
used to compare RSN info, not only single AKM values.
This adds checks if MFP is set to 0 or 1:
0 - Always fail if the frequency is 6GHz
1 - Fail if MFPC=0 and the frequency is 6GHz.
If HW is capable set MFPR=1 for 6GHz
This is a new band defined in the WiFi 6E (ax) amendment. A completely
new value is needed due to channel reuse between 2.4/5 and 6GHz.
util.c needed minimal updating to prevent compile errors which will
be fixed later to actually handle this band. WSC also needed a case
added for 6GHz but the spec does not outline any RF Band value for
6GHz so the 5GHz value will be returned in this case.
sae.c was failing to build on some platforms:
error: implicit declaration of function 'reallocarray'; did you mean 'realloc'?
[-Werror=implicit-function-declaration]
In certain rare cases IWD gets a link down event before nl80211 ever sends
a disconnect event. Netdev notifies station of the link down which causes
station to be freed, but netdev remains in the same state. Then later the
disconnect event arrives and netdev still thinks its connected, calls into
(the now freed) station object and causes a crash.
To fix this netdev_connect_free() is now called on any link down events
which will reset the netdev object to a proper state.
src/netdev.c:netdev_link_notify() event 16 on ifindex 16
src/netdev.c:netdev_mlme_notify() MLME notification Del Station(20)
src/netdev.c:netdev_link_notify() event 16 on ifindex 16
src/netdev.c:netdev_mlme_notify() MLME notification Deauthenticate(39)
src/netdev.c:netdev_deauthenticate_event()
src/netdev.c:netdev_link_notify() event 16 on ifindex 16
src/station.c:station_free()
src/netconfig.c:netconfig_destroy()
src/resolve.c:resolve_systemd_revert() ifindex: 16
src/station.c:station_roam_state_clear() 16
src/netdev.c:netdev_mlme_notify() MLME notification Disconnect(48)
src/netdev.c:netdev_disconnect_event()
Received Deauthentication event, reason: 3, from_ap: false
0 0x472fa4 in station_disconnect_event src/station.c:2916
1 0x472fa4 in station_netdev_event src/station.c:2954
2 0x43a262 in netdev_disconnect_event src/netdev.c:1213
3 0x43a262 in netdev_mlme_notify src/netdev.c:5471
4 0x6706eb in process_multicast ell/genl.c:1029
5 0x6706eb in received_data ell/genl.c:1096
6 0x65e630 in io_callback ell/io.c:120
7 0x65a94e in l_main_iterate ell/main.c:478
8 0x65b0b3 in l_main_run ell/main.c:525
9 0x65b0b3 in l_main_run ell/main.c:507
10 0x65b5cc in l_main_run_with_signal ell/main.c:647
11 0x4124d7 in main src/main.c:532
The difference between the existing code is that IWD will send the
authentication request, making it the initiator.
This handles the use case where IWD is provided a peers URI containing
its bootstrapping key rather than IWD always providing its own URI.
A new DBus API was added, ConfigureEnrollee().
Using ConfigureEnrollee() IWD will act as a configurator but begin by
traversing a channel list (URI provided or default) and waiting for
presence announcements (with one caveat). When an announcement is
received IWD will send an authentication request to the peer, receive
its reply, and send an authentication confirm.
As with being a responder, IWD only supports configuration to the
currently connected BSS and will request the enrollee switch to this
BSS's frequency to preserve network performance.
The caveat here is that only one driver (ath9k) supports multicast frame
registration which prevents presence frame from being received. In this
case it will be required the the peer URI contains a MAC and channel
information. This is because IWD will jump right into sending auth
requests rather than waiting for a presence announcement.
The frame watch which covers the presence procedure (and most
frames for that matter) needs to support multicast frames for
presence to work. Doing this in frame-xchg seems like the right
choice but only ath9k supports multicast frame registration.
Because of this limited support DPP will register for these frames
manually.
Parses K (key), M (mac), C (class/channels), and V (version) tokens
into a new structure dpp_uri_info. H/I are not parsed since there
currently isn't any use for them.
This was caught by static analysis. As is common this should never
happen in the real world since the only way this can fail (apart from
extreme circumstances like OOM) is if the key size is incorrect, which
it will never be.
Static analysis flagged that 'path' was never being checked (which
should not ever be NULL) but during that review I noticed stat()
was being called, then fstat afterwards.
Recently systemd added the ability to pass secret credentials to
services via LoadCredentialEncrypted/SetCredentialEncrypted. Once
set up the service is able to read the decrypted credentials from
a file. The file path is found in the environment variable
CREDENTIALS_DIRECTORY + an identifier. The value of SystemdEncrypt
should be set to the systemd key ID used when the credential was
created.
When SystemdEncrypt is set IWD will attempt to read the decrypted
secret from systemd. If at any point this fails warnings will be
printed but IWD will continue normally. Its expected that any failures
will result in the inability to connect to any networks which have
previously encrypted the passphrase/PSK without re-entering
the passphrase manually. This could happen, for example, if the
systemd secret was changed.
Once the secret is read in it is set into storage to be used for
profile encryption/decryption.
Using storage_decrypt() hotspot can also support profile encyption.
The hotspot consortium name is used as the 'ssid' since this stays
consistent between hotspot networks for any profile.
Some users don't like the idea of storing network credentials in
plaintext on the file system. This patch implements an option to
encrypt such profiles using a secret key. The origin of the key can in
theory be anything, but would typically be provided by systemd via
'LoadEncryptedCredential' setting in the iwd unit file.
The encryption operates on the entire [Security] group as well as all
embedded groups. Once encrypted the [Security] group will be replaced
with two key/values:
EncryptedSalt - A random string of bytes used for the encryption
EncryptedSecurity - A string of bytes containing the encrypted
[Security] group, as well as all embedded groups.
After the profile has been encrypted these values should not be
modified. Note that any values added to [Security] after encryption
has no effect. Once the profile is encrypted there is no way to modify
[Security] without manually decrypting first, or just re-creating it
entirely which effectively treated a 'new' profile.
The encryption/decryption is done using AES-SIV with a salt value and
the network SSID as the IV.
Once a key is set any profiles opened will automatically be encrypted
and re-written to disk. Modules using network_storage_open will be
provided the decrypted profile, and will be unaware it was ever
encrypted in the first place. Similarly when network_storage_sync is
called the profile will by automatically encrypted and written to disk
without the caller needing to do anything special.
A few private storage.c helpers were added to serve several purposes:
storage_init/exit():
This sets/cleans up the encryption key direct from systemd then uses
extract and expand to create a new fixed length key to perform
encryption/decryption.
__storage_decrypt():
Low level API to decrypt an l_settings object using a previously set
key and the SSID/name for the network. This returns a 'changed' out
parameter signifying that the settings need to be encrypted and
re-written to disk. The purpose of exposing this is for a standalone
decryption tool which does not re-write any settings.
storage_decrypt():
Wrapper around __storage_decrypt() that handles re-writing a new
profile to disk. This was exposed in order to support hotspot profiles.
__storage_encrypt():
Encrypts an l_settings object and returns the full profile as data
This got merged without a few additional fixes, in particular an
over 80 character line and incorrect length check.
Fixes: d8116e8828 ("dpp-util: add dpp_point_from_asn1()")
When we detect a new phy being added, we schedule a filtered dump of
the newly detected WIPHY and associated INTERFACEs. This code path and
related processing of the dumps was mostly shared with the un-filtered
dump of all WIPHYs and INTERFACEs which is performed when iwd starts.
This normally worked fine as long as a single WIPHY was created at a
time. However, if multiphy new phys were detected in a short amount of
time, the logic would get confused and try to process phys that have not
been probed yet. This resulted in iwd trying to create devices or not
detecting devices properly.
Fix this by only processing the target WIPHY and related INTERFACEs
when the filtered dump is performed, and not any additional ones that
might still be pending.
While here, remove a misleading comment:
manager_wiphy_check_setup_done() would succeed only if iwd decided to
keep the default interfaces created by the kernel.
This debug print was before any checks which could bail out prior to
autoconnect starting. This was confusing because debug logs would
contain multiple "station_autoconnect_start()" prints making you think
autoconnect was started several times.
The periodic scan code was refactored to make normal scans and
periodic scans consistent by keeping both in the same queue. But
that change left out the abort path where periodic scans were not
actually removed from the queue.
This fixes a rare crash when a periodic scan has been triggered and
the device goes down. This path never removes the request from the
queue but still frees it. Then when the scan context is removed the
stale request is freed again.
0 0x4bb65b in scan_request_cancel src/scan.c:202
1 0x64313c in l_queue_clear ell/queue.c:107
2 0x643348 in l_queue_destroy ell/queue.c:82
3 0x4bbfb7 in scan_context_free src/scan.c:209
4 0x4c9a78 in scan_wdev_remove src/scan.c:2115
5 0x42fecd in netdev_free src/netdev.c:965
6 0x445827 in netdev_destroy src/netdev.c:6507
7 0x52beb9 in manager_config_notify src/manager.c:765
8 0x67084b in process_multicast ell/genl.c:1029
9 0x67084b in received_data ell/genl.c:1096
10 0x65e790 in io_callback ell/io.c:120
11 0x65aaae in l_main_iterate ell/main.c:478
12 0x65b213 in l_main_run ell/main.c:525
13 0x65b213 in l_main_run ell/main.c:507
14 0x65b72c in l_main_run_with_signal ell/main.c:647
15 0x4124e7 in main src/main.c:532
If netdev_connect_failed is called before netdev_get_oci_cb() the
netdev's handshake will be destroyed and ultimately crash when the
callback is called.
This patch moves the cancelation into netdev_connect_free rather than
netdev_free.
++++++++ backtrace ++++++++
0 0x7f4e1787d320 in /lib64/libc.so.6
1 0x42634c in handshake_state_set_chandef() at src/handshake.c:1057
2 0x40a11b in netdev_get_oci_cb() at src/netdev.c:2387
3 0x483d7b in process_unicast() at ell/genl.c:986
4 0x480d3c in io_callback() at ell/io.c:120
5 0x48004d in l_main_iterate() at ell/main.c:472 (discriminator 2)
6 0x4800fc in l_main_run() at ell/main.c:521
7 0x48032c in l_main_run_with_signal() at ell/main.c:649
8 0x403e95 in main() at src/main.c:532
9 0x7f4e17867b75 in /lib64/libc.so.6
+++++++++++++++++++++++++++
Commit 4d2176df29 ("handshake: Allow event handler to free handshake")
introduced a re-entrancy guard so that handshake_state objects that are
destroyed as a result of the event do not cause a crash. It rightly
used a temporary object to store the passed in handshake. Unfortunately
this caused variable shadowing which resulted in crashes fixed by commit
d22b174a73 ("handshake: use _hs directly in handshake_event").
However, since the temporary was no longer used, this fix itself caused
a crash:
#0 0x00005555f0ba8b3d in eapol_handle_ptk_1_of_4 (sm=sm@entry=0x5555f2b4a920, ek=0x5555f2b62588, ek@entry=0x16, unencrypted=unencrypted@entry=false) at src/eapol.c:1236
1236 handshake_event(sm->handshake,
(gdb) bt
#0 0x00005555f0ba8b3d in eapol_handle_ptk_1_of_4 (sm=sm@entry=0x5555f2b4a920, ek=0x5555f2b62588, ek@entry=0x16, unencrypted=unencrypted@entry=false) at src/eapol.c:1236
#1 0x00005555f0bab118 in eapol_key_handle (unencrypted=<optimized out>, frame=<optimized out>, sm=0x5555f2b4a920) at src/eapol.c:2343
#2 eapol_rx_packet (proto=<optimized out>, from=<optimized out>, frame=<optimized out>, unencrypted=<optimized out>, user_data=0x5555f2b4a920) at src/eapol.c:2665
#3 0x00005555f0bac497 in __eapol_rx_packet (ifindex=62, src=src@entry=0x5555f2b62574 "x\212 J\207\267", proto=proto@entry=34958, frame=frame@entry=0x5555f2b62588 "\002\003",
len=len@entry=121, noencrypt=noencrypt@entry=false) at src/eapol.c:3017
#4 0x00005555f0b8c617 in netdev_control_port_frame_event (netdev=0x5555f2b64450, msg=0x5555f2b62588) at src/netdev.c:5574
#5 netdev_unicast_notify (msg=msg@entry=0x5555f2b619a0, user_data=<optimized out>) at src/netdev.c:5613
#6 0x00007f60084c9a51 in dispatch_unicast_watches (msg=0x5555f2b619a0, id=<optimized out>, genl=0x5555f2b3fc80) at ell/genl.c:954
#7 process_unicast (nlmsg=0x7fff61abeac0, genl=0x5555f2b3fc80) at ell/genl.c:973
#8 received_data (io=<optimized out>, user_data=0x5555f2b3fc80) at ell/genl.c:1098
#9 0x00007f60084c61bd in io_callback (fd=<optimized out>, events=1, user_data=0x5555f2b3fd20) at ell/io.c:120
#10 0x00007f60084c536d in l_main_iterate (timeout=<optimized out>) at ell/main.c:478
#11 0x00007f60084c543e in l_main_run () at ell/main.c:525
#12 l_main_run () at ell/main.c:507
#13 0x00007f60084c5670 in l_main_run_with_signal (callback=callback@entry=0x5555f0b89150 <signal_handler>, user_data=user_data@entry=0x0) at ell/main.c:647
#14 0x00005555f0b886a4 in main (argc=<optimized out>, argv=<optimized out>) at src/main.c:532
This happens when the driver does not support rekeying, which causes iwd to
attempt a disconnect and re-connect. The disconnect action is
taken during the event callback and destroys the underlying eapol state
machine. Since a temporary isn't used, attempting to dereference
sm->handshake results in a crash.
Fix this by introducing a UNIQUE_ID macro which should prevent shadowing
and using a temporary variable as originally intended.
Fixes: d22b174a73 ("handshake: use _hs directly in handshake_event")
Fixes: 4d2176df29 ("handshake: Allow event handler to free handshake")
Reported-By: Toke Høiland-Jørgensen <toke@toke.dk>
Tested-by: Toke Høiland-Jørgensen <toke@toke.dk>
There is no need to punch the holes for netdev/wheel groups to send to
the .Agent interface. This is only done by the iwd daemon itself and
the policy for user 'root' already takes care of this.
A select few drivers send this instead of SIGNAL_MBM. The docs say this
value is the signal 'in unspecified units, scaled to 0..100'. The range
for SIGNAL_MBM is -10000..0 so this can be scaled to the MBM range easy
enough...
Now, this isn't exactly correct because this value ultimately gets
returned from GetOrderedNetworks() and is documented as 100 * dBm where
in reality its just a unit-less signal strength value. Its not ideal, but
this patch at least will fix BSS ranking for these few drivers.
The 'at_console' D-Bus policy setting has been deprecated for more then
10 years and could be ignored at any time in the future. Moreover, while
the intend was to allow locally logged on users to interact with iwd, it
didn't actually do that.
More info at https://www.spinics.net/lists/linux-bluetooth/msg75267.html
and https://gitlab.freedesktop.org/dbus/dbus/-/issues/52
Therefor remove the 'at_console' setting block.
On Debian (based) systems, there is a standard defined group which is
allowed to manage network interfaces, and that is the 'netdev' group.
So add a D-Bus setting block to grant the 'netdev' group that access.
Building on GCC 8 resulted in this compiler error.
src/sae.c:107:25: error: implicit declaration of function 'reallocarray';
did you mean 'realloc'? [-Werror=implicit-function-declaration]
sm->rejected_groups = reallocarray(NULL, 2, sizeof(uint16_t));
src/erp.c:134:10: error: comparison of integer expressions of different
signedness: 'unsigned int' and 'int' [-Werror=sign-compare]
src/eap-ttls.c:378:10: error: comparison of integer expressions of different signedness: 'uint32_t' {aka 'unsigned int'} and 'int' [-Werror=sign-compare]
Fixes the following crash:
#0 0x000211c4 in netdev_connect_event (msg=<optimized out>, netdev=0x2016940) at src/netdev.c:2915
#1 0x76f11220 in process_multicast (nlmsg=0x7e8acafc, group=<optimized out>, genl=<optimized out>) at ell/genl.c:1029
#2 received_data (io=<optimized out>, user_data=<optimized out>) at ell/genl.c:1096
#3 0x76f0da08 in io_callback (fd=<optimized out>, events=1, user_data=0x200a560) at ell/io.c:120
#4 0x76f0ca78 in l_main_iterate (timeout=<optimized out>) at ell/main.c:478
#5 0x76f0cb74 in l_main_run () at ell/main.c:525
#6 l_main_run () at ell/main.c:507
#7 0x76f0cdd4 in l_main_run_with_signal (callback=callback@entry=0x18c94 <signal_handler>, user_data=user_data@entry=0x0)
at ell/main.c:647
#8 0x00018178 in main (argc=<optimized out>, argv=<optimized out>) at src/main.c:532
This crash was introduced in commit:
4d2176df29 ("handshake: Allow event handler to free handshake")
The culprit seems to be that 'hs' is being used both in the caller and
in the macro. Since the macro defines a variable 'hs' in local block
scope, it overrides 'hs' from function scope. Yet (_hs) still evaluates
to 'hs' leading the local variable to be initialized with itself. Only
the 'handshake_event(hs, HANDSHAKE_EVENT_SETTING_KEYS))' is affected
since it is the only macro invocation that uses 'hs' from function
scope. Thus, the crash would only happen on hardware supporting handshake
offload (brcmfmac).
Fix this by removing the local scope variable declaration and evaluate
(_hs) instead.
Fixes: 4d2176df29 ("handshake: Allow event handler to free handshake")
- Ensure that input isn't an empty string
- Ensure that EINVAL errno (which could be optionally returned by
strto{ul|l} is also checked.
- Since strtoul allows '+' and '-' characters in input, ensure that
input which is expected to be an unsigned number doesn't start with
'-'
Given an ASN1 blob of the right form, parse and create
an l_ecc_point object. The form used is specific to DPP
hence why this isn't general purpose and put into dpp-util.
Like in ap.c, allow the event callback to mark the handshake state as
destroyed, without causing invalid accesses after the callback has
returned. In this case the crash was because try_handshake_complete
needed to access members of handshake_state after emitting the event,
as well as access the netdev, which also has been destroyed:
==257707== Invalid read of size 8
==257707== at 0x408C85: try_handshake_complete (netdev.c:1487)
==257707== by 0x408C85: try_handshake_complete (netdev.c:1480)
(...)
==257707== Address 0x4e187e8 is 856 bytes inside a block of size 872 free'd
==257707== at 0x484621F: free (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==257707== by 0x437887: ap_stop_handshake (ap.c:151)
==257707== by 0x439793: ap_del_station (ap.c:316)
==257707== by 0x43EA92: ap_station_disconnect (ap.c:3411)
==257707== by 0x43EA92: ap_station_disconnect (ap.c:3399)
==257707== by 0x454276: p2p_group_event (p2p.c:1006)
==257707== by 0x439147: ap_event (ap.c:281)
==257707== by 0x4393AB: ap_new_rsna (ap.c:390)
==257707== by 0x4393AB: ap_handshake_event (ap.c:1010)
==257707== by 0x408C7F: try_handshake_complete (netdev.c:1485)
==257707== by 0x408C7F: try_handshake_complete (netdev.c:1480)
(...)
Previously we added logic to defer doing anything in ap_free() to after
the AP event handler has returned so that ap_event() has a chance to
inform whoever called it that the ap_state has been freed. But there's
also a chance that the event handler is destroying both the AP and the
netdev it runs on, so after the handler has returned we can't even use
netdev_get_wdev_id or netdev_get_ifindex. The easiest solution seems to
be to call ap_reset() in ap_free() even if we're within an event handler
to ensure we no longer need any external objects. Also make sure
ap_reset() can be called multiple times.
Another option would be to watch for NETDEV_WATCH_EVENT_DEL and remove
our reference to the netdev (because there's no need actually call
l_rtnl_ifaddr_delete or frame_watch_wdev_remove if the netdev was
destroyed -- frame_watch already tracks netdev removals), or to save
just the ifindex and the wdev id...
The purpose of this was to have a single utility to both cancel an
existing offchannel operation (if one exists) and start a new one.
The problem was the previous offchannel operation was being canceled
first which opened up the radio work queue to other items. This is
not desireable as, for example, a scan would end up breaking the
DPP protocol most likely.
Starting the new offchannel then canceling is the correct order of
operations but to do this required saving the new ID, canceling, then
setting offchannel_id to the new ID so dpp_presence_timeout wouldn't
overwrite the new ID to zero.
This also removes an explicit call to offchannel_cancel which is
already done by dpp_offchannel_start.
Several members are named based on initiator/responder (i/r)
terminology. Eventually both initiator and responder will be
supported so rename these members to use own/peer naming
instead.
ASN1 parsing will soon be required which will need some utilities in
asn1-private.h. To avoid duplication include this private header and
replace the OID's with the defined structures as well as remove the
duplicated macros.
station_set_scan_results takes an autoconnect flag which was being
set true in both regular/quick autoconnect scans. Since OWE networks
are processed after setting the scan results IWD could end up
connecting to a network before all the OWE hidden networks are
populated.
To fix this regular/quick autoconnect results will set the flag to
false, then process OWE networks, then start autoconnect. If any
OWE network scans are pending station_autoconnect_start will fail
but will pick back up after the hidden OWE scan.
scan_request_failed and scan_finished remove the finished scan_request
from the request queue right away, before calling the callback. This
breaks those clients that rely on scan_cancel working on such requests
(i.e. to force the destroy callback to be invoked synchronously, see
a0911ca778 ("station: Make sure roam_scan_id is always canceled").
Fix this by removing the scan_request from the request queue after
invoking the callback. Also provide a re-entrancy guard that will make
sure that the scan_request isn't removed in scan_cancel itself.
There are similar operations being performed but with different
callbacks and userdata, depending on whether 'sr' is NULL or not.
Optimize the function flow slightly to make if-else unnecessary.
While here, update the comment. periodic scans are now scheduled only
based on the periodic timeout timer.
If periodic scan is active and we receive a SCAN_ABORTED event, we would
still invoke the periodic scan callback with an error. This is rather
pointless since the periodic scan callback cannot do anything useful
with this information. Fix that.
We should never reach a point where NEW_SCAN_RESULTS or SCAN_ABORTED are
received before a corresponding TRIGGER_SCAN is received. Even if this
does happen, there's no harm from processing the commands anyway.
This makes it a little easier to book-keep the started variable. Since
scan_request already has a 'passive' bit-field, there should be no
storage penalty.
If scan_cancel is called on a scan_request that is 'finished' but with
the GET_SCAN command still in flight, it will trigger a crash as
follows:
Received Deauthentication event, reason: 2, from_ap: true
src/station.c:station_disconnect_event() 11
src/station.c:station_disassociated() 11
src/station.c:station_reset_connection_state() 11
src/station.c:station_roam_state_clear() 11
src/scan.c:scan_cancel() Trying to cancel scan id 6 for wdev 200000002
src/scan.c:scan_cancel() Scan is at the top of the queue, but not triggered
src/scan.c:get_scan_done() get_scan_done
Aborting (signal 11) [/home/denkenz/iwd-master/src/iwd]
++++++++ backtrace ++++++++
#0 0x7f9871aef3f0 in /lib64/libc.so.6
#1 0x41f470 in station_roam_scan_notify() at /home/denkenz/iwd-master/src/station.c:2285
#2 0x43936a in scan_finished() at /home/denkenz/iwd-master/src/scan.c:1709
#3 0x439495 in get_scan_done() at /home/denkenz/iwd-master/src/scan.c:1739
#4 0x4bdef5 in destroy_request() at /home/denkenz/iwd-master/ell/genl.c:676
#5 0x4c070b in l_genl_family_cancel() at /home/denkenz/iwd-master/ell/genl.c:1960
#6 0x437069 in scan_cancel() at /home/denkenz/iwd-master/src/scan.c:842
#7 0x41dc2e in station_roam_state_clear() at /home/denkenz/iwd-master/src/station.c:1594
#8 0x41dd2b in station_reset_connection_state() at /home/denkenz/iwd-master/src/station.c:1619
#9 0x41dea4 in station_disassociated() at /home/denkenz/iwd-master/src/station.c:1644
The happens because get_scan_done callback is still called as a result of
l_genl_cancel. Add a re-entrancy guard in the form of 'canceled'
variable in struct scan_request. If set, get_scan_done will skip invoking
scan_finished.
It isn't clear what 'l_queue_peek_head() == results->sr' check was trying
to accomplish. If GET_SCAN dump was scheduled, then it should be
reported. Drop it.
results->sr is set to NULL for 'opportunistic' scans which were
triggered externally. See scan_notify() for details. However,
get_scan_done would only invoke scan_finished (and thus the periodic
scan callback sc->sp.callback) only if the scan queue was empty. It
should do so in all cases.
The point type was being hard coded to 0x3 (BIT1) which may have resulted
in the peer subtracting Y from P when reading in the point (depending on
if Y was odd or not).
Instead set the compressed type to whatever avoids the subtraction which
both saves IWD from needing to do it, as well as the peer.
The intent of this check is to make sure that at least 2 bytes are
available for reading. However, the unintended consequence is that tags
with a zero length at the end of input would be rejected.
While here, rework the check to be more resistant to potential
overflow conditions.
The DPP spec says nothing about how to handle re-transmits but it
was found in testing this can happen relatively easily for a few
reasons.
If the configurator requests a channel switch but does not get onto
the new channel quick enough the enrollee may have already sent the
authenticate response and it was missed. Also by nature of how the
kernel goes offchannel there are moments in time between ROC when
the card is idle and not receiving any frames.
Only frames where there was no ACK will be retransmitted. If the
peer received the frame and dropped it resending the same frame wont
do any good.
Now the result is sent immediately. Prior a connect attempt or
scan could have started, potentially losing this frame. In addition
the offchannel operation is cancelled after sending the result
which will allow the subsequent connect or scan to happen much
faster since it doesn't have to wait for ROC to expire.
The previous (incorrect) else was removed since it ended up
printing in most cases since the if clause returned. This should
have been an else if conditional from the start and only print if the
station device was not found.
IWD may be in the middle of some long operation, e.g. scanning.
If the URI is returned before IWD is ready, a configurator could
start sending frames and IWD either wont receive them, or will
be unable to respond quickly.
The offchannel priority was also changed to zero, which matches the
priority of frames. Currently there should be no interaction between
offchannel and connect (previous offchannel priority).
Periodic scans were handled specially where they were only
started if no other requests were pending in the scan queue.
This is fine, and what we want, but this can actually be
handled automatically by nature of the wiphy work queue rather
than needing to check the request queue explicitly.
Instead we can insert periodic scans at a lower priority than
other scans. This puts them at the end of the work queue, as
well as allows future requests to jump ahead if a periodic scan
has not yet started.
Eventually, once all pending scans are done, the peridoic scan
may begin. This is no different than the preivous behavior and
avoids the need for any special checks once scan requests
complete.
One check was added to address the problem of the periodic scan
timer firing before the scan could even start. Currently this
happened to be handled fine in scan_periodic_queue, as it checks
the queue length. Since this check was removed we must see check
for this condition inside scan_periodic_timeout.
This adds a priority argument to scan_common rather than hard
coding it when inserting the work item and uses the newly
defined wiphy priority for scanning.
Work priority was never explicitly defined anywhere, and a module
using wiphy_radio_work APIs needed to ensure it was not inserting
at a priority that would interfere with other work.
Now all the types of work have been defined with their own priority
and future priorities can easily be added before, after, or in
between existing priorities.
- Mostly problems with whitespace:
- Use of spaces instead of tabs
- Stray spaces before closing ')
- Missing spaces
- Missing 'void' from function declarations & definitions that
take no arguments.
- Wrong indentation level
When this attribute is included, the initiator is requesting all
future frames be sent on this channel. There is no reason for a
configurator to act on this attribute (at least for now) so the
request frame will be dropped in this case. Enrollees will act
on it by switching to the new channel and sending the authentication
response.
While connected the driver ends up choosing quite small ROC
durations leading to excessive calls to ROC. This also will
negatively effect any wireless performance for the current
network and possibly lead to missed DPP frames.
Currently the enrollee relied on autoconnect to handle connecting
to the newly configured network. This usually resulted in poor
performance since periodic scans are done at large intervals apart.
Instead first check if the newly configured network is already
in IWD's network queue. If so it can be connected to immediately.
If not, a full scan must be done and results given to station.
With better JSON support the configuration request object
can now be fully parsed. As stated in the previous comment
there really isn't much use from the configurator side apart
from verifying mandatory values are included.
This patch also modifies the configuration result to handle
sending non 'OK' status codes in case of JSON parsing errors.
json_iter_parse is only meant to work on objects while
json_iter_next is only meant to work on arrays.
This adds checks in both APIs to ensure they aren't being
used incorrectly.
Arrays can now be parsed using the JSON_ARRAY type (stored in
a struct json_iter) then iterated using json_iter_next. When
iterating the type can be checked with json_iter_get_type. For
each iteration the value can be obtained using any of the type
getters (int/uint/boolean/null).
This adds support for boolean, (unsigned) integers, and
null types. JSON_PRIMITIVE should be used as the type when
parsing and the value should be struct json_iter.
Once parsed the actual value can be obtained using one of
the primitive getters. If the type does not match they will
return false.
If using JSON_OPTIONAL with JSON_PRIMITIVE the resulting
iterator can be checked with json_iter_is_valid. If false
the key/value was not found or the type was not matching.
First, this was renamed to 'count_tokens_in_container' to be
more general purpose (i.e. include future array counting).
The way the tokens are counted also changed to be more intuitive.
While the previous way was correct, it was somewhat convoluted in
how it worked (finding the next parent of the objects parent).
Instead we can use the container token itself as the parent and
begin counting tokens. When we find a token with a parent index
less than the target we have reached the end of this container.
This also works for nested containers, including arrays since we
no longer rely on a key (which an array element would not have).
For example::
{
"first":{"foo":"bar"},
"second":{"foo2":"bar2"}
}
index 0 <overall object>
index 1 "first" with parent 0
index 2 {"foo":"bar"} with parent 1
Counting tokens inside "first"'s object we have:
index 3 "foo" with parent 2
index 4 "bar" with parent 3
If we continue counting we reach:
index 5 "second" with parent 0
This terminates the counting loop since the parent index is
less than '2' (the index of {"foo":"bar"} object).
In file included from ./ell/ell.h:15,
from ../../src/dpp.c:29:
../../src/dpp.c: In function ‘authenticate_request’:
../../ell/log.h:79:22: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 8 has type ‘size_t’ {aka ‘unsigned int’} [-Wformat=]
79 | l_log(L_LOG_DEBUG, "%s:%s() " format, __FILE__, \
| ^~~~~~~~~~
../../ell/log.h:54:16: note: in definition of macro ‘l_log’
54 | __func__, format "\n", ##__VA_ARGS__)
| ^~~~~~
../../ell/log.h:103:31: note: in expansion of macro ‘L_DEBUG_SYMBOL’
103 | #define l_debug(format, ...) L_DEBUG_SYMBOL(__debug_desc, format, ##__VA_ARGS__)
| ^~~~~~~~~~~~~~
../../src/dpp.c:1235:3: note: in expansion of macro ‘l_debug’
1235 | l_debug("I-Nonce has unexpected length %lu", i_nonce_len);
| ^~~~~~~
Direct leak of 64 byte(s) in 1 object(s) allocated from:
#0 0x7fa226fbf0f8 in __interceptor_malloc (/usr/lib/gcc/x86_64-pc-linux-gnu/9.4.0/libasan.so.5+0x10c0f8)
#1 0x688c98 in l_malloc ell/util.c:62
#2 0x6c2b19 in msg_alloc ell/genl.c:740
#3 0x6cb32c in l_genl_msg_new_sized ell/genl.c:1567
#4 0x424f57 in netdev_build_cmd_authenticate src/netdev.c:3285
#5 0x425b50 in netdev_sae_tx_authenticate src/netdev.c:3385
Direct leak of 7 byte(s) in 1 object(s) allocated from:
#0 0x7fd748ad00f8 in __interceptor_malloc (/usr/lib/gcc/x86_64-pc-linux-gnu/9.4.0/libasan.so.5+0x10c0f8)
#1 0x688c21 in l_malloc ell/util.c:62
#2 0x4beec7 in handshake_state_set_vendor_ies src/handshake.c:324
#3 0x464e4e in station_handshake_setup src/station.c:1203
#4 0x472a2f in __station_connect_network src/station.c:2975
#5 0x473a30 in station_connect_network src/station.c:3078
#6 0x4ed728 in network_connect_8021x src/network.c:1497
Fixes: f24cfa481b ("handshake: Add setter for vendor IEs")
This implements a configurator in the responder role. Currently
configuring an enrollee is limited to only the connected network.
This is to avoid the need to go offchannel for any reason. But
because of this a roam, channel switch, or disconnect will cause
the configuration to fail as none of the frames are being sent
offchannel.
Added both enrollee and configurator roles, as well as the needed
logic inside the authentication protocol to verify role compatibility.
The dpp_sm's role will now be used when setting capability bits making
the auth protocol agnostic to enrollees or configurators.
This also allows the card to re-issue ROC if it ends in the middle of
authenticating or configuring as well as add a maximum timeout for
auth/config protocols.
IO errors were also handled as these sometimes can happen with
certain drivers but are not fatal.
Allows creating a new configuration object based on settings, ssid,
and akm suite (for configurator role) as well as converting a
configuration object to JSON.
Rather than hard coding ad0, use the actual frame data. There really
isn't a reason this would differ (only status attribute) but just
in case its better to use the frame data directly.
This is a minimal implementation only supporting legacy network
configuration, i.e. only SSID and PSK/passphrase are supported.
Missing features include:
- Fragmentation/comeback delay support
- DPP AKM support
- 8021x/PKEX support
This implements the DPP protocol used to authenticate to a
DPP configurator.
Note this is not a full implementation of the protocol and
there are a few missing features which will be added as
needed:
- Mutual authentication (needed for BLE bootstrapping)
- Configurator support
- Initiator role
The presence procedure implemented is a far cry from what the spec
actually wants. There are two reason for this: a) the kernels offchannel
support is not at a level where it will work without rather annoying
work arounds, and b) doing the procedure outlined in the spec will
result in terrible discovery performance.
Because of this a simpler single channel announcement is done by default
and the full presence procedure is left out until/if it is needed.
This is a minimal wrapper around jsmn.h to make things a bit easier
for iterating through a JSON object.
To use, first parse the JSON and create a contents object using
json_contents_new(). This object can then be used to initialize a
json_iter object using json_iter_init().
The json_iter object can then be parsed with json_iter_parse by
passing in JSON_MANDATORY/JSON_OPTIONAL arguments. Currently only
JSON_STRING and JSON_OBJECT types are supported. Any JSON_MANDATORY
values that are not found will result in an error.
If a JSON_OPTIONAL string is not found, the pointer will be NULL.
If a JSON_OPTIONAL object is not found, this iterator will be
initialized but 'start' will be -1. This can be checked with a
convenience macro json_object_not_found();
Static analysis was not happy since this return can be negative and
it was being fed into an unsigned argument. In reality this cannot
happen since the key buffer is always set to the maximum size supported
by any curves.
This module provides a convenient wrapper around both
CMD_[CANCEL_]_REMAIN_ON_CHANNEL APIs.
Certain protocols require going offchannel to send frames, and/or
wait for a response. The frame-xchg module somewhat does this but
has some limitations. For example you cannot just go offchannel;
an initial frame must be sent out to start the procedure. In addition
frame-xchg does not work for broadcasts since it expects an ACK.
This module is much simpler and only handles going offchannel for
a duration. During this time frames may be sent or received. After
the duration the caller will get a callback and any included error
if there was one. Any offchannel request can be cancelled prior to
the duration expriring if the offchannel work has finished early.
The disconnect event handler was mistakenly bailing out if FT or
reassociation was going on. This was done because a disconnect
event is sent by the kernel when CMD_AUTH/CMD_ASSOC is used.
The problem is an AP could also disconnect IWD which should never
be ignored.
To fix this always parse the disconnect event and, if issued by
the AP, always notify watchers of the disconnect.
LLD 13 and GNU ld 2.37 support -z start-stop-gc which allows garbage
collection of C identifier name sections despite the __start_/__stop_
references. GNU ld before 2015-10 had the behavior as well. Simply set
the retain attribute so that GCC 11 (if configure-time binutils is 2.36
or newer)/Clang 13 will set the SHF_GNU_RETAIN section attribute to
prevent garbage collection.
Without the patch, there are linker errors with -z start-stop-gc
(LLD default) when -Wl,--gc-sections is used:
```
ld.lld: error: undefined symbol: __start___eap
>>> referenced by eap.c
>>> src/eap.o:(eap_init)
```
The remain attribute will not be needed if the metadata sections are
referenced by code directly.
ap.c has been mostly careful to call the event handler at the end of any
externally called function to allow methods like ap_free() to be called
within the handler, but that isn't enough. For example in
ap_del_station we may end up emitting two events: STATION_REMOVED and
DHCP_LEASE_EXPIRED. Use a slightly more complicated mechanism to
explicitly guard ap_free calls inside the event handler.
To make it easier, simplify cleanup in ap_assoc_reassoc with the use of
_auto_.
In ap_del_station reorder the actions to send the STATION_REMOVED event
first as the DHCP_LEASE_EXPIRED is a consequence of the former and it
makes sense for the handler to react to it first.
src/eap.c: In function 'eap_rx_packet':
src/eap.c:419:50: error: 'vendor_type' may be used uninitialized in this function [-Werror=maybe-uninitialized]
419 | (type == EAP_TYPE_EXPANDED && vendor_id == (id) && vendor_type == (t))
| ^~
src/eap.c:430:11: note: 'vendor_type' was declared here
430 | uint32_t vendor_type;
It isn't clear why GCC complains about vendor_type, but not vendor_id.
But in all cases if type == EAP_TYPE_EXPANDED, then vendor_type and
vendor_id are set. Silence this spurious warning.
There is an unchecked NULL pointer access in network_has_open_pair.
open_info can be NULL, when out of multiple APs in range that advertise
the same SSID some advertise OWE transition elments and some don't.
The Hotspot 2.0 spec has some requirements that IWD was missing depending
on a few bits in extended capabilities and the HS2.0 indication element.
These requirements correspond to a few sysfs options that can be set in
the kernel which are now set on CONNECTED and unset on DISCONNECTED.
Netconfig was the only user of sysfs but now other modules will
also need it.
Adding existing API for IPv6 settings, a IPv4 and IPv6 'supports'
checker, and a setter for IPv4 settings.
The way a SA Query was done following a channel switch was slightly
incorrect. One because it is only needed when OCVC is set, and two
because IWD was not waiting a random delay between 0 and 5000us as
lined out by the spec. This patch fixes both these issues.
Cache the latest v4 and v6 domain string lists in struct netconfig state
to be able to more easily detect changes in those values in future
commits. For that split netconfig_set_domains's code into this function,
which now only commits the values in netconfig->v{4,6}_domain{,s} to the
resolver, and netconfig_domains_update() which figures out the active
domains string list and saves it into netconfig->v{4,6}_domain{,s}. This
probably saves some cycles as the callers can now decide to only
recalculate the domains list which may have changed.
While there simplify netconfig_set_domains return type to void as the
result was always 0 anyway and was never checked by callers.
Cache the latest v4 and v6 DNS IP string lists in struct netconfig state
to be able to more easily detect changes in those values in future
commits. For that split netconfig_set_dns's code into this function,
which now only commit the values in netconfig->dns{4,6}_list to the
resolver, and netconfig_dns_list_update() which figures out the active
DNS IP address list and saves it in netconfig->dns{4,6} list. This
probably saves some cycles as the callers can now decide to only
recalculate the dns_list which may have changed.
While there simplify netconfig_set_dns return type to void as the result
was always 0 anyway and was never checked by callers.
Cache the latest v4 and v6 gateway IP string in struct netconfig state
to be able to more easily detect changes in those values in future
commits and perhaps to simplify the ..._routes_install functions.
netconfig_ipv4_get_gateway's out_mac parameter can now be NULL. While
editing that function fix a small formatting annoyance.
Use a separate fils variable to make the code a bit prettier.
Also make sure that the out_mac parameter is not NULL prior to storing
the gateway_mac in it.
Add netconfig_enabled() and use that in all places that want to know
whether network configuration is enabled. Drop the enable_network_config
deprecated setting, which was only being handled in one of these 5 or so
places.
This code path was never tested and used to ensure a OWE transition
candidate gets selected over an open one (e.g. if all the BSS's are
blacklisted). But this logic was incorrect and the path was being
taken for BSS's that did not contain the owe_trans element, basically
all BSS's. For RSN's this was somewhat fine since the final check
would set a candidate, but for open BSS's the loop would start over
and potentially complete the loop without ever returning a candidate.
If fallback was false, NULL would be returned.
To fix this only take the OWE transition path if its an OWE transition
BSS, i.e. inverse the logic.
Normally Beacon Reporting subelements are present only if repeated
measurements are requested. However, an all-zero Beacon Reporting
subelement is included by some implementations. Handle this case
similarly to the absent case.
Since Reporting Detail subelement is listed as 'extensible', make sure
that the length check is not overly restrictive. We only interpret the
first field.
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.
