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.
The procedure for setting extended key IDs is different from the
single PTK key. The key ID is toggled between 0 and 1 and the new
key is set as RX only, then set to RX/TX after message 4/4 goes
out.
Since netdev needs to set this new key before sending message 4,
eapol can include a built message which netdev will store if
required (i.e. using PAE).
ext_key_id_capable indicates the handshake has set the capability bit
in the RSN info. This will only be set if the AP also has the capability
set.
active_tk_index is the key index the AP chose in message 3. This is
now used for both legacy (always zero) and extended key IDs.
Move the reading of ControlPortOverNL80211 into wiphy itself and
renamed wiphy_control_port_capable to wiphy_control_port_enabled.
This makes things easier for any modules interested in control
port support since they will only have to check this one API rather
than read the settings and check capability.
Expose the Device Address property for each peer. The spec doesn't say
much about how permanent the address or the name are, although the
device address by definition lives longer than the interface addresses.
However the device address is defined to be unique and the name is not
so the address can be used to differentiate devices with identical name.
Being unique also may imply that it's assigned globally and thus
permanent.
Network Manager uses the P2P device address when saving connection
profiles (and will need it from the backend) and in this case it seems
better justified than using the name.
The address is already in the object path but the object path also
includes the local phy index which may change for no reason even when
the peer's address hasn't changed so the path is not useful for
remembering which device we've connected to before. Looking at only
parts of the path is considered wrong.
Some drivers might not actually support control port properly even if
advertised by mac80211. Introduce a new method to wiphy that will take
care of looking up any driver quirks that override the presence of
NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211
Make consecutive calls to netconfig_load_settings() memory-leak safe by
introducing a netconfig_free_settings convenience method. This method
will free any settings that are allocated as a result of
netconfig_load_settings() and will be called from netconfig_free() to
ensure that any settings are freed as a result of netconfig_destroy().
For symmetry with IPv4, save the command id for this netlink command so
we can later add logic to the callback as well as be able to cancel the
command. No functional change in this commit alone.
FT/FILS handle their own PMK derivation but rekeys still require
using the 4-way handshake. There is some ambiguity in the spec whether
or not the PMKID needs to be included in message 1/4 and it appears
that when rekeying after FT/FILS hostapd does not include a PMKID.
The handshake contains the current BSS's RSNE/WPA which may differ
from the FT-over-DS target. When verifying the target BSS's RSNE/WPA
IE needs to be checked, not the current BSS.
If the deauth path was triggered IWD would deauth but end up
calling the connect callback with whatever result netdev had
set, e.g. 'NETDEV_RESULT_OK'. This, of course, caused station
some confusion.
FT-over-DS cannot use OCV due to how the kernel works. This means
we could connect initially with OCVC set, but a FT-over-DS attempt
needs to unset OCVC. Set OCVC false when rebuilding the RSNE for
reassociation.
The FT-over-DS action stage builds an FT-Request which contains an
RSNE. Since FT-over-DS will not support OCV add a boolean to
ft_build_authenticate_ies so the OCVC bit can be disabled rather
than relying on the handshake setting.
This modifies the FT logic to fist call get_oci() before
reassociation. This allows the OCI to be included in reassociation
and in the 4-way handshake later on.
The code path for getting the OCI had to be slightly changed to
handle an OCI that is already set. First the handshake chandef is
NULL'ed out for any new connection. This prevents a stale OCI from
being used. Then some checks were added for this case in
netdev_connect_event and if chandef is already set, start the 4-way
handshake.
netconfig_load_settings is called when establishing a new initial
association to a network. This function tries to update dhcp/dhcpv6
clients with the MAC address of the netdev being used. However, it is
too early to update the MAC here since netdev might need to powercycle
the underlying network device in order to update the MAC (i.e. when
AddressRandomization="network" is used).
If the MAC is set incorrectly, DHCP clients are unable to obtain the
lease properly and station is stuck in "connecting" mode indefinitely.
Fix this by delaying MAC address update until netconfig_configure() is
invoked.
Fixes: ad228461ab ("netconfig: Move loading settings to new method, refactor")
If the AP advertises FT-over-DS support it likely wants us to use
it. Additionally signal_low is probably going to be true since IWD
has started a roam attempt.
When netdev goes down so does station, but prior to netdev calling
the neighbor report callback. The way the logic was written station
is dereferenced prior to checking for any errors, causing a use
after free.
Since -ENODEV is used in this case check for that early before
accessing station.
This adds a utility to convert a chandef obtained from the kernel into a
3 byte OCI element format containing the operating class, primary
channel and secondary channel center frequency index.
This changes scan_bss from using separate members for each
OWE transition element data type (ssid, ssid_len, and bssid)
to a structure that holds them all.
This is being done because OWE transition has option operating
class and channel bytes which will soon be parsed. This would
end up needing 5 separate members in scan_bss which is a bit
much for a single IE that needs to be parsed.
This makes checking the presense of the IE more convenient
as well since it can be done with a simple NULL pointer check
rather than having to l_memeqzero the BSSID.
These members are currently stored in scan_bss but with the
addition of operating class/band info this will become 5
separate members. This is a bit excessive to store in scan_bss
separately so instead this structure can hold everything related
to the OWE transition IE.
Add a utility for setting the OCI obtained from the hardware (prior to
handshake starting) as well as a utility to validate the OCI obtained
from the peer.
This adds a utility that can convert an operating class + channel
combination to a frequency. Operating class is assumed to be a global
operating class from 802.11 Appendix E4.
This information can be found in Operating Channel Information (OCI) IEs,
as well as OWE Transition Mode IEs.
Calling handshake_state_setup_own_ciphers from within
handshate_state_set_authenticator_ie was misleading. In all cases the
supplicant chooses the AKM. This worked since our AP code only ever
advertises a single AKM, but would not work in the general case.
Similarly, the supplicant would choose which authentication type to use
by either sending the WPA1 or WPA2 IE (or OSEN). Thus the setting of
the related variables in handshake_state_set_authenticator_ie was also
incorrect. In iwd, the supplicant_ie would be set after the
authenticator_ie, so these settings would be overwritten in most cases.
Refactor these two setters so that the supplicant's chosen rsn_info
would be used to drive the handshake.
reallocarray has been added to glibc relatively recently (version 2.26,
from 2017) and apparently not all users run new enough glibc. Moreover,
reallocarray is not available with uclibc-ng. So use realloc if
reallocarray is not available to avoid the following build failure
raised since commit 891b78e9e8:
/home/giuliobenetti/autobuild/run/instance-3/output-1/host/lib/gcc/xtensa-buildroot-linux-uclibc/10.3.0/../../../../xtensa-buildroot-linux-uclibc/bin/ld: src/sae.o: in function `sae_rx_authenticate':
sae.c:(.text+0xd74): undefined reference to `reallocarray'
Fixes:
- http://autobuild.buildroot.org/results/c6d3f86282c44645b4f1c61882dc63ccfc8eb35a
There isn't much control station has with how BSS's are inserted to
a network object. The rank algorithm makes that decision. Because of
this we could end up in a situation where the Open BSS is preferred
over the OWE transition BSS.
In attempt to better handle this any Open BSS in this type of network
will not be chosen unless its the only candidate (e.g. no other BSSs,
inability to connect with OWE, or an improperly configured network).
OWE Transition is described in the WiFi Alliance OWE Specification
version 1.1. The idea behind it is to support both legacy devices
without any concept of OWE as well as modern ones which support the
OWE protocol.
OWE is a somewhat special type of network. Where it advertises an
RSN element but is still "open". This apparently confuses older
devices so the OWE transition procedure was created.
The idea is simple: have two BSS's, one open, and one as a hidden
OWE network. Each network advertises a vendor IE which points to the
other. A device sees the open network and can connect (legacy) or
parse the IE, scan for the hidden OWE network, and connect to that
instead.
Care was taken to handle connections to hidden networks directly.
The policy is being set that any hidden network with the WFA OWE IE
is not connectable via ConnectHiddenNetwork(). These networks are
special, and can only be connected to via the network object for
the paired open network.
When scan results come in from any source (DBus, quick, autoconnect)
each BSS is checked for the OWE Transition IE. A few paths can be
taken here when the IE is found:
1. The BSS is open. The BSSID in the IE is checked against the
current scan results (excluding hidden networks). If a match is
found we should already have the hidden OWE BSS and nothing
else needs to be done (3).
2. The BSS is open. The BSSID in the IE is not found in the
current scan results, and the open network also has no OWE BSS
in it. This will be processed after scan results.
3. The BSS is not open and contains the OWE IE. This BSS will
automatically get added to the network object and nothing else
needs to be done.
After the scan results each network is checked for any non-paired
open BSS's. If found a scan is started for these BSS's per-network.
Once these scan results come in the network is notified.
From here network.c can detect that this is an OWE transition
network and connect to the OWE BSS rather than the open one.
Specifically OWE networks with multiple open/hidden BSS's are troublesome
to scan for with the current APIs. The scan parameters are limited to a
single SSID and even if that was changed we have the potential of hitting
the max SSID's per scan limit. In all, it puts the burden onto the caller
to sort out the SSIDs/frequencies to scan for.
Rather than requiring station to handle this a new scan API was added,
scan_owe_hidden() which takes a list of open BSS's and will automatically
scan for the SSIDs in the OWE transition IE for each.
It is slightly optimized to first check if all the hidden SSID's are the
same. This is the most likely case (e.g. single pair or single network)
and a single scan command can be used. Otherwise individual scan commands
are queued for each SSID/frequency combo.
handshake_util_ap_ie_matches() is used to make sure that the RSN element
received from the Authenticator during handshake / association response
is the same as the one advertised in Beacon/Probe Response frames. This
utility tries to bitwise compare the element first, and only if that
fails, compares RSN members individually.
For FT, bitwise comparison will always fail since the PMKID has to be
included by the Authenticator in any RSN IEs included in Authenticate
& Association Response frames.
Perform the bitwise comparison as an optimization only during processing
of eapol message 3/4. Also keep the parsed rsn information for future
use and to possibly avoid re-parsing it during later checks.
DBus scan is performed in several subsets. In certain corner-case
circumstances it would be possible for autoconnect to run after each
subset scan. Instead, trigger autoconnect only after the dbus scan
completes.
This also works around a condition where ANQP results could trigger
autoconnect too early.
Several invocations of station_set_scan_results() base the
'add_to_autoconnect' parameter on station_is_autoconnecting(). Simplify
the code by having station_set_scan_results() invoke that itself.
'add_to_autoconnect' now becomes an 'intent' parameter, specifying
whether autoconnect path should be invoked as a result of these scan
results or not when station is in an appropriate state. Rename
'add_to_autoconnect' parameter to make this clearer.
If the frequency of the bss is not in the list of frequencies for the
current scan, then this is a cached bss. It was likely already
processed for ANQP before, so skip it.
IWD has restricted SSIDs to only utf8 so they can be displayed but
with the addition of OWE transition networks this is an unneeded
restriction (for these networks). The SSID of an OWE transition
network is never displayed to the user so limiting to utf8 isn't
required.
Allow non-utf8 SSIDs to be scanned for by including the length in
the scan parameters and not relying on strlen().
This is a parser for the WFA OWE Transition element. For now the
optional band/channel bytes will not be parsed as hostapd does not
yet support these and would also require the 802.11 appendix E-1
to be added to IWD. Because of this OWE Transition networks are
assumed to be on the same channel as their open counterpart.
in6_addr.__in6_u.__u6_addr8 is glibc-specific and named differently in
the headers shipped with musl libc for example. The POSIX compliant and
universal way of accessing it is in6_addr.s6_addr.
This was actually broken if triggered because __network_connect
checks if network->connect_after_owe_hidden is set and returns
already in progress. We want to keep this behavior though for
obvious reasons.
To fix this station_connect_network can be called directly which
bypasses the check. This is essentially how ANQP avoids this
problem as well.
Similar to ANQP a connect call could come in while station is
scanning for OWE hidden networks. This is supported in the same
manor by saving away the dbus message and resuming the connection
after the hidden OWE scan.
With the addition of OWE transition network needs to be notified
of the hidden OWE scan which is quite similar to how it is notified
of ANQP. The ANQP event watch can be made generic and reused to
allow other events besides ANQP.
This is being added to support OWE transition mode. For these
type of networks the OWE BSS may contain a different SSID than
that of the network, but the WFA spec requires this be hidden
from the user. This means we need to set the handshake SSID based
on the BSS rather than the network object.
Refactor netconfig_set_dns to be a bit easier to follow and remove use
of macros. Also bail out early if no DNS addresses are provided instead
of building an empty DNS list since resolve_set_dns() simply returns if
a NULL or empty DNS list is provided.
Kernel keeps transmitting authentication frames until told to stop or an
authentication frame the kernel considers 'final' is received. Detect
cases where the kernel would keep retransmitting, and if auth_proto
encounters a fatal protocol error, prevent these retransmissions from
occuring by sending a Deauthenticate command to the kernel.
Additionally, treat -EBADMSG/-ENOMSG return from auth_proto specially.
These error codes are meant to convey that a frame should be silently
dropped and retransmissions should continue.
This works around a hostapd bug (described more in the TODO comment)
which is exposed because of the kernels overly agressive re-transmit
behavior on missed ACKs. Combined this results in a death if the
initial commit is not acked. This behavior has been identified in
consumer access points and likely won't ever be patched for older
devices. Because of this IWD must work around the problem which can
be eliminated by not sending out this commit message.
This bug was reported to the hostapd ML:
https://lists.infradead.org/pipermail/hostap/2021-September/039842.html
This change should not cause any compatibility problems to non-hostapd
access points and is identical to how wpa_supplicant treats this
scenario.
If a commit is received while in an accepted state the spec states
the scalar should be checked against the previous commit and if
equal the message should be silently dropped.
In netconfig_load_settings apply the DNS overrides strings we've loaded
instead of leaking them.
Fixes: ad228461ab ("netconfig: Move loading settings to new method, refactor")
netdev now assumes the SSID was set in the handshake (normally via
network_handshake_setup) but WSC calls netdev_connect directly so
it also should set the SSID.
In order to support OWE in the CMD_CONNECT path the scan_bss parameter
needs to be removed since this is lost after netdev_connect returns.
Nearly everything needed is also stored in the handshake except the
privacy capability which is now being mirrored in the netdev object
itself.
