It is possible for a zero-length anti-clogging token payload to cause
IWD to abort. If the length passed into sae_process_anti_clogging was
1, l_memdup would be called with a size of -1. This will cause malloc
to abort.
Fix this by checking for a minimum packet length and dropping the
packet if the length is too small.
The HS20 indication element should always be included during
(Re)Association per the spec. This removes the need for a
dedicated boolean, and now the hs20_ie can be used instead.
The hotspot spec specifically mentions the roaming consortium OI be
3 or 5 bytes long. This requirement also prevents potential buffer
overflows if the user were to configure a long roaming consortium OI.
If the scan was triggered and later aborted, make sure to reset the
triggered value when the CMD_NEW_SCAN_RESULTS event comes in.
src/station.c:station_enter_state() Old State: disconnected, new state: connecting
src/scan.c:scan_notify() Scan notification 33
src/station.c:station_netdev_event() Associating
src/scan.c:scan_notify() Scan notification 34
Aborting (signal 11) [/home/denkenz/iwd-master/src/iwd]
++++++++ backtrace ++++++++
#0 0x7efd4d6a2ef0 in /lib64/libc.so.6
#1 0x42b20d in scan_notify() at src/scan.c:1383
In the same fashion as the WSC WFA OUI, ie.[ch] will now expose the
other vendor OUIs to avoid duplication across multiple files in IWD
as well as used in iwmon.
P2P probe requests are to be sent at min 6.0 Mb/s using OFDM,
specifically the 802.11b rates are prohibited (section 2.4.1 in Wi-Fi
P2p Technical Spec v1.7), some of which use CCK modulation. This is
already the default for 5G but for 2.4G the drivers generally do this
if we set the NL80211_ATTR_TX_NO_CCK_RATE flags with
NL80211_CMD_TRIGGER_SCAN.
The length check was incorrectly assuming that PPS MO ID or
ANQP Domain ID would be present in the IE. Both these are optional
and without then the minimum length is 5 bytes, not 7.
Per the hotspot 2.0 spec, if a matching roaming consortium OI is
found it should be added to the (Re)Association request. vendor_ies
can now be provided to netdev_connect, which get appended to the IE
attribute.
This API will attempt to find a matching roaming consortium OI
if present in the config file. A single matching OI is returned
or NULL if one was not found.
Hotspot 2.0 network providers allow 'roaming' between a users home
network and other providers networks, assuming they are part of the
same roaming consortium. The roaming consortium is advertised as an
IE in beacon/probe frames.
In terms of the hotspot config files this is similar to HESSID, where
if the AP advertises the roaming consortium IE, and the config file
matches we do not need to do ANQP in order to connect.
This is duplicated when the first scan_bss is added to a network
object that contains the IE. Any future BSS's added will not re-add
the IE. Its assumed that all BSS's under a network will contain the
same roaming consortium OIs.
Parses up to 3 (the max) roaming consortium OIs out of the roaming
consortium IE. If more OIs are available via ANQP the 'num_anqp_out'
value will be set to indicate how many more OIs are available.
Builds according to the hotspot 2.0 spec using the vendor specific
IE.
Declare structures to hold the parsed contents of the P2P IEs and WSC
IEs in P2P-related frames and add functions to free memory used by
those structures.
Define structs and types for most P2P attributes and p2p_parse_attrs
similar to wsc_parse_attrs -- a generic parser for attributes in a P2P
IE payload. This parser may write into the provided buffer even on
error but it's private to p2putil.c. The local callers will take care
of keeping the user-provided buffers untouched on error.
Add a utility for building the simplified WSC IEs used in P2P action
frames and public action frames. Only three types of WSC attributes are
mandatory in those frames (but different subsets are needed by different
frame types) so add a single utility for building those IEs. We may
need to add some more optional attributes to those IEs later.
The ifindex is used to index the netdevs in the system (wlan, ethernet,
etc.) but we can also do wifi scanning on interfaces that have no
corresponding netdev object, like the P2P-device virtual interfaces.
Use the wdev id's to reference interfaces, the nl80211 api doesn't care
whether we use a NL80211_ATTR_IFINDEX or NL80211_ATTR_WDEV. Only
wireless interfaces have a wdev id.
Save the actual cmd_id returned from l_genl_family_dump and zero it in
the get_scan_done. There's no need to zero it in scan_cancel because
get_scan_done gets called automatically.
Store the scan_context pointer in scan_results directly instead of
storing the ifindex. We now cancel ongoing GET_SCAN commands when the
scan_context is being freed so there's no point going through the extra
step of looking up the scan_context by ifindex inside the command
callback to guard against non-existent scan_contexts.
method.ops is NULL, which causes method.ops->exit to crash. This
adds a check that method.ops is not NULL before dereferencing.
Fixes:
Aborting (signal 11) [/home/jprestwo/iwd/src/iwd]
++++++++ backtrace ++++++++
0 0x7f016b59cf20 in /lib/x86_64-linux-gnu/libc.so.6
1 0x432057 in resolve_exit() at /home/jprestwo/iwd/src/resolve.c:295
2 0x403b61 in iwd_modules_exit() at /home/jprestwo/iwd/src/main.c:195
3 0x7f016b57fb97 in /lib/x86_64-linux-gnu/libc.so.6
+++++++++++++++++++++++++++
The original idea was to allow the provisioning file to include HESSID
without the NAIRealmNames. Configuring this way would allow for ANQP
to be skipped completely, assuming the AP advertises its HESSID.
The way the code was written still required NAIRealmNames to be
provided in the provisioning file.
The framework enables the service specific implementations
to provide its own variations for the DNS installation tasks.
The selection of the address resolution service can be done
through dns_resolve_method setting.
The module is responsible for the configuration of the address
resolution services. It will consist of the multiple service
specific plugins such as: systemd-resolved plugin, dnsmasq
plugin, etc.
If supported by the driver, we can create an interface directly with a
random MAC if configured to do so. If the driver does not have this
capability, then tell netdev to perform the necessary logic as part of
the interface initialization procedure.
#0 0x7f5e25e71930 in /lib64/libc.so.6
#1 0x446faa in hs20_config_free() at src/hotspot.c:63
#2 0x469542 in l_queue_clear() at ell/queue.c:109
#3 0x4694e7 in l_queue_destroy() at ell/queue.c:83
#4 0x4475c1 in hotspot_exit() at src/hotspot.c:273
#5 0x403170 in iwd_modules_exit() at src/main.c:195
#6 0x404085 in main() at src/main.c:531
#7 0x7f5e25e5cbde in /lib64/libc.so.6
Regulatory domain management is now completely handled by the kernel, so
iwd doesn't really need to query or be aware of changes to this. This
may change in the future, but for now this code has not been used and
can be safely gotten rid of.
After a scan, station can now pause future scans and start ANQP requests
to discover Hotspot's NAI realm. This lets us check if the AP's NAI realm
matches any stored hotspot configuration files. If so we can connect to
this network. If the network provides an HESSID and a matching one is
found in a hotspot provisioning file we can skip ANQP and directly connect
as this is expected to be our 'home network'
The actual ANQP request was handled by netdev, but in the case of P2P
their may be no netdev. For this reason all functionality needed for
an ANQP request has been moved into anqp.c. There are still a few netdev
references, which need to be removed when P2P is introduced. Leaving them
in for now as its still going to work as a first pass implementation
The initial ANQP parser design did not work well with how the hotspot
implementation was turning out. For one, much care was taken into parsing
the EAP credentials which are not really required. The assumption is
that any hotspot network will already be provisioned, so checking that
the EAP parameters match is a bit overkill. Instead only the NAI Realms
will be checked. This greatly simplifies the NAI realm parser, as now it
can just return a string list of realms instead of the full EAP
credential info.
This module will be in charge of managing Hotspot provisioning files
stored under the .hotspot/ directory. This includes a dir watch to
handle file changes/removal as well as an API to match a network
object to a hotspot provisioning file.
Hotspot networks are supposed to include an HESSID in the scan
results. This is more or less an identifier for the overall
network. In addition, the NAI Realms can be obtained via ANQP
and should be the same for each BSS. Since both HESSID and NAI
realms should be the same for a given network in range we can
store these values in the network object itself. This also allows
us to easily find hotspot configuration files by looking at
the HESSID/NAI Realms directly in the network object as opposed
to individual scan_bss's.
In order to do ANQP efficiently IWD needs the ability to suspend scanning
temporarily. This is because both scanning and ANQP go offchannel and must
remain off channel for some amount of time. This cannot be done
simultaneously and if e.g. ANQP is requested after a scan is already
pending, the kernel will wait till that scan finishes before sending out
the frame.
Use memset instead. explicit_bzero should only be used when we're
wiping a secret just prior to the encopassing storage being freed. The
compiler would usually optimize away the memset, leaving the secrets
around.
In rtnlutil we're simply zeroing the structure prior to filling it, so
the use of explicit_bzero is not needed and brings confusion to the
reader since no secrets are being wiped.
netconfig is interested in three station states: connected,
disconnected and connected after it has roamed. On connected
it tries to obtain a new DHCP lease, on disconnected it stops
the DHCP client and discards all addresses from interface, on
connected after roaming it will try to request a previously
issued address.
iwd keeps track of the addresses assigned to the managed
interfaces. The list of assigned IPv4/IPv6 addresses is stored
in ifaddr_list inside of netconfig. The tracking of the IP
addresses will help to remove them from an interface once they
are no longer valid.
netconfig module will be responsible for the orchestration
of the network configuration with the IP addresses.
iwd creates one netconfig structure per interface index.
The purpose of this struct is to hold all of the interface
related addressing states such as: assigned dhcp
clients, known addresses, routes, etc.
A not-yet-merged kernel patch will enable the FRAME_WAIT_CANCEL
event to be emitted when a CMD_FRAME duration expires. This can
shortcut the ridiculously long timeout that is required making
GAS requests with no response drastically quicker to handle.
This adds a new API netdev_anqp_request which will send out a GAS
request, parses the GAS portion of the response and forwards the
ANQP response to the callers callback.
This IE tells us what Advertisement Protocols the AP supports. This
is only here to look for ANQP support, so all this does is iterate
through all other Advertisement Protocol tuples looking for ANQP.
If found, anqp_capable is set in the scan_bss
Currently these are geared to support the WiFi Alliance Hotspot 2.0
ANQP elements, which all fall under the vendor specific ANQP element.
anqp_iter_next behaves similar to the genl parsers, where the id, length
and data will be returned as out parameters. Currently there is only
vendor support for Hotspot 2.0. anqp_iter_is_hs20 can be used to setup
the subtype, length, and data pointer to parse any Hotspot 2.0 ANQP
elements. From here the subtype can be checked and a vendor specific
parser for that subtype can be used to parse the data, e.g.
hs20_parse_osu_provider_nai.
The vendor specific IE was being parsed only to check if the AP supported
WPA, which used a Microsoft OUI. Hotspot/OSEN uses neither WPA or RSN
(although its nearly identical to RSN) so the we also need to check for
this Wifi-Alliance OUI and set bss->osen (new) if found.
The OSEN AKM uses the vendor specific IE, so when finding the RSNE
element we need to handle it specially to ensure that its both
a vendor specific element and it matches the WFA OUI since other
vendor specific elements may be included.
The OSEN AKM is nearly identical to the RSN IE, but differs slightly.
For one, OSEN is encapsulated into the vendor specific IE, and includes
the WFA OUI before the 'normal' RSN elements. OSEN also does not include
a WPA version, since its not technically WPA/WPA2.
Some of the RSN parsing was made common so both RSN/OSEN parsing could
use it.
The handshake object had 4 setters for authenticator/supplicant IE.
Since the IE ultimately gets put into the same buffer, there really
only needs to be a single setter for authenticator/supplicant. The
handshake object can deal with parsing to decide what kind of IE it
is (WPA or RSN).
The Hotspot 2.0 spec introduces 'Anonymous EAP-TLS' as a new EAP method
to be used with OSEN/Hotspot. The protocol details of this aren't
relevant to this patch, but one major difference is that it uses the
expanded EAP type rather than the TLS type. Since the common TLS code
was written with only EAP_TYPE_TLS in mind the vendor ID/type cause the
EAP packet to be malformed when using the expanded EAP type.
To handle this the common TLS code now checks the EAP type, and if its
expanded we shift the payload 7 bytes further to account for the extra
header data.
802.11 defines GAS (generic advertisement service) which can be used
to query supported advertisement protocols from an AP before
authentication/association. Hotspot/OSEN only care about the ANQP
protocol, but the way the IE is structured potentially requires
iterating through several tuples before you reach the ANQP protocol
identifier. Because of this we define all protocol identifiers.
This adds some checks for the FT_OVER_FILS AKMs in station and netdev
allowing the FILS-FT AKMs to be selected during a connection.
Inside netdev_connect_event we actually have to skip parsing the IEs
because FILS itself takes care of this (needs to handle them specially)
FILS unfortunately is a special case when it comes to fast transition.
We have to process the FT IEs internally since we cannot trigger the
same initial mobility association code path (via netdev).
FT over FILS-SHA384 uses a 24 byte FT MIC rather than the 16 byte MIC
used for all other AKMs. This change allows both the FT builder/parser
to handle both lengths of MIC. The mic length is now passed directly
into ie_parse_fast_bss_transition and ie_build_fast_bss_transition
FILS-FT is a special case with respect to the PTK keys. The KCK getter
was updated to handle both FT-FILS AKMs, by returning the offset in
the PTK to the special KCK generated during FILS. A getter for the KCK
length was added, which handles the SHA384 variant. The PTK size was
also updated since FILS-FT can generate an additional 56 bytes of PTK
ifaddr is not guaranteed to be initialized, I'm not sure why there was
no compiler warning. Also replace a | with a || for boolean conditions
and merge the wiphy check with that line.
When handling a scan finished event for a scan we haven't started check
that we were not halfway through a scan request that would have its
results flushed by the external scan.
FT-over-DS is a way to do a Fast BSS Transition using action frames for
the authenticate step. This allows a station to start a fast transition
to a target AP while still being connected to the original AP. This,
in theory, can result in less carrier downtime.
The existing ft_sm_new was removed, and two new constructors were added;
one for over-air, and another for over-ds. The internals of ft.c mostly
remain the same. A flag to distinguish between air/ds was added along
with a new parser to parse the action frames rather than authenticate
frames. The IE parsing is identical.
Netdev now just initializes the auth-proto differently depending on if
its doing over-air or over-ds. A new TX authenticate function was added
and used for over-ds. This will send out the IEs from ft.c with an
FT Request action frame.
The FT Response action frame is then recieved from the AP and fed into
the auth-proto state machine. After this point ft-over-ds behaves the
same as ft-over-air (associate to the target AP).
Some simple code was added in station.c to determine if over-air or
over-ds should be used. FT-over-DS can be beneficial in cases where the
AP is directing us to roam, or if the RSSI falls below a threshold.
It should not be used if we have lost communication to the AP all
(beacon lost) as it only works while we can still talk to the original
AP.
To support FT-over-DS this API needed some slight modifications:
- Instead of setting the DA to netdev->handshake->aa, it is just set to
the same address as the 'to' parameter. The kernel actually requires
and checks for these addresses to match. All occurences were passing
the handshake->aa anyways so this change should have no adverse
affects; and its actually required by ft-over-ds to pass in the
previous BSSID, so hard coding handshake->aa will not work.
- The frequency is is also passed in now, as ft-over-ds needs to use
the frequency of the currently connected AP (netdev->frequency get
set to the new target in netdev_fast_transition. Previous frequency
is also saved now).
- A new vector variant (netdev_send_action_framev) was added as well
to support sending out the FT Request action frame since the FT
TX authenticate function provides an iovec of the IEs. The existing
function was already having to prepend the action frame header to
the body, so its not any more or less copying to do the same thing
with an iovec instead.
Since FT already handles processing the FT IE's (and building for
associate) it didn't make sense to have all the IE building inside
netdev_build_cmd_ft_authenticate. Instead this logic was moved into
ft.c, and an iovec is now passed from FT into
netdev_ft_tx_authenticate. This leaves the netdev command builder
unburdened by the details of FT, as well as prepares for FT-over-DS.
Blacklist some drivers known to crash when interfaces are deleted or
created so that we don't even attempt that before falling back to using
the default interface.
Read the driver name for each wiphy from sysfs if available. I didn't
find a better way to obtain the driver name for a phy than by reading
the dir name that the "driver" symlink points at. For an existing
netdev this can be done using the SIOCETHTOOL ioctl.
manager_interface_dump_done would use manager_create_interfaces() at the
end of the loop iterating over pending_wiphys. To prevent it from
crashing make sure manager_create_interfaces never frees the pending
wiphy state and instead make the caller check whether it needs to be
freed so it can be done safely inside loops.
Instead of having two separate types of scans make the periodic scan
logic a layer on top of the one-off scan requests, with minimum code to
account for the lower priority of those scans and the fact that periodic
scans also receive results from external scans. Also try to simplify
the code for both the periodic and one-off scans. In the SCAN_RESULTS
and SCAN_ABORT add more complete checks of the current request's state
so we avoid some existing crashes related to external scans.
scan_send_next_cmd and start_next_scan_request are now just one function
since their funcionality was similar and start_next_scan_request is used
everywhere. Also the state after the trigger command receives an EBUSY
is now the same as when a new scan is on top of the queue so we have
fewer situations to consider.
This code still does not account for fragmented scans where an external
scan between two or our fragments flushes the results and we lose some
of the results, or for fragmented scans that take over 30s and the
kernel expires some results (both situations are unlikely.)
In both netdev_{authenticate,associate}_event there is no need to check
for in_ft at the start since netdev->ap will always be set if in_ft is
set.
There was also no need to set eapol_sm_set_use_eapol_start, as setting
require_handshake implies this and achieves the same result when starting
the SM.
Since FT operates over Authenticate/Associate, it makes the most sense
for it to behave like the other auth-protos.
This change moves all the FT specific processing out of netdev and into
ft.c. The bulk of the changes were strait copy-pastes from netdev into
ft.c with minor API changes (e.g. remove struct netdev).
The 'in_ft' boolean unforunately is still required for a few reasons:
- netdev_disconnect_event relies on this flag so it can ignore the
disconnect which comes in when doing a fast transition. We cannot
simply check netdev->ap because this would cause the other auth-protos
to not handle a disconnect correctly.
- netdev_associate_event needs to correctly setup the eapol_sm when
in FT mode by setting require_handshake and use_eapol_start to false.
This cannot be handled inside eapol by checking the AKM because an AP
may only advertise a FT AKM, and the initial mobility association
does require the 4-way handshake.
Now the 'ft' module, previously ftutil, will be used to drive FT via
the auth-proto virtual class. This renaming is in preparation as
ftutil will become obsolete since all the IE building/processing is
going to be moved out of netdev. The new ft.c module will utilize
the existing ftutil functionality, but since this is now a full blown
auth protocol naming it 'ft' is better suited.
The duplicate/similar code in netdev_associate_event and
netdev_connect_event leads to very hard to follow code, especially
when you throw OWE/SAE/FILS or full mac cards into the mix.
Currently these protocols finish the connection inside
netdev_associate_event, and set ignore_connect_event. But for full
mac cards we must finish the connection in netdev_connect_event.
In attempt to simplify this, all connections will be completed
and/or the 4-way started in netdev_connect_event. This satisfies
both soft/full mac cards as well as simplifies the FT processing
in netdev_associate_event. Since the FT IEs can be processed in
netdev_connect_event (as they already are to support full mac)
we can assume that any FT processing inside netdev_associate_event
is for a fast transition, not initial mobility association. This
simplifies netdev_ft_process_associate by removing all the blocks
that would get hit if transition == false.
Handling FT this way also fixes FT-SAE which was broken after the
auth-proto changes since the initial mobility association was
never processed if there was an auth-proto running.
SAE was a bit trickier than OWE/FILS because the initial implementation
for SAE did not include parsing raw authenticate frames (netdev skipped
the header and passed just the authentication data). OWE/FILS did not
do this and parse the entire frame in the RX callbacks. Because of this
it was not as simple as just setting some RX callbacks. In addition,
the TX functions include some of the authentication header/data, but
not all (thanks NL80211), so this will require an overhaul to test-sae
since the unit test passes frames from one SM to another to test the
protocol end-to-end (essentially the header needs to be prepended to
any data coming from the TX functions for the end-to-end tests).
Since ERP is only used for FILS and not behaving in the 'normal' ERP
fashion (dealing with actual EAP data, timeouts etc.) we can structure
ERP as a more synchronous protocol, removing the need for a complete
callback.
Now, erp_rx_packet returns a status, so FILS can decide how to handle
any failures. The complete callback was also removed in favor of a
getter for the RMSK (erp_get_rmsk). This allows FILS to syncronously
handle ERP, and potentially fail directly in fils_rx_authenticate.
A new eapol API was added specifically for FILS (eapol_set_started). Since
either way is special cased for FILS, its a bit cleaner to just check the
AKM inside eapol_start and, if FILS, dont start any timeouts or start the
handshake (effectively what eapol_set_started was doing).
This is a new concept applying to any protocol working over authenticate
and/or associate frames (OWE/SAE/FILS). All these protocols behave
similarly enough that they can be unified into a handshake driver
structure.
Now, each protocol will initialize this auth_proto structure inside
their own internal data. The auth_proto will be returned from
the initializer which netdev can then use to manage the protocol by
forwarding authenticate/associate frames into the individual drivers.
The auth_proto consists only of function pointers:
start - starts the protocol
free - frees the driver data
rx_authenticate - receive authenticate frame
rx_associate - receive associate frame
auth_timeout - authenticate frame timed out
assoc_timeout - associate frame timed out
If the setting is true we'll not attempt to remove or create
interfaces on any wiphys and will only use the default interface
(if it exists). If false, force us managing the interfaces. Both
values override the auto logic.
An unexpected Associate event would cause iwd to crash when accessing
netdev->handshake->mde. netdev->handshake is only set if we're
attempting to connect or connected somewhere so check netdev->connected
first.
FILS needs to allocate an extra 16 bytes of key data for the AES-SIV
vector. Instead of leaving it up to the caller to figure this out (as
was done with the GTK builder) eapol_create_common can allocate the
extra space since it knows the MIC length.
This also updates _create_gtk_2_of_2 as it no longer needs to create
an extra data array.
Since FILS does not use a MIC, the 1/4 handler would always get called
for FILS PTK rekeys. We can use the fact that message 1/4 has no MIC as
well as no encrypted data to determine which packet it is. Both no MIC
and no encrypted data means its message 1/4. Anything else is 3/4.
For FILS rekeys, we still derive the PTK using the 4-way handshake.
And for FILS-SHA384 we need the SHA384 KDF variant when deriving.
This change adds both FILS-SHA256 and FILS-SHA384 to the checks
for determining the SHA variant.
crypto_derive_pairwise_ptk was taking a boolean to decide whether to
use SHA1 or SHA256, but for FILS SHA384 may also be required for
rekeys depending on the AKM.
crypto_derive_pairwise_ptk was changed to take l_checksum_type instead
of a boolean to allow for all 3 SHA types.
AP still relies on the get_data/set_length semantics. Its more convenient
to still use these since it avoids the need for extra temporary buffers
when building the rates IE.
The TLV builder APIs were not very intuative, and in some (or all)
cases required access to the builder structure directly, either to
set the TLV buffer or to get the buffer at the end.
This change adds a new API, ie_tlv_builder_set_data, which both sets
the length for the current TLV and copies the TLV data in one go.
This will avoid the need for memcpy(ie_tlv_builder_get_data(...),...)
ie_tlv_builder_finalize was also changed to return a pointer to the
start of the build buffer. This will eliminate the need to access
builder.tlv after building the TLVs.
ie_tlv_builder_init was changed to take an optional buffer to hold
the TLV data. Passing NULL/0 will build the TLV in the internal
buffer. Passing in a pointer and length will build into the passed
in buffer.
Let manager.c signal to wiphy.c when the wiphy parsing from the genl
messages is complete. When we query for existing wiphy using the
GET_WIPHY dump command we get many genl messages per wiphy, on a
notification we only get one message. So after wiphy_create there may
be one or many calls to wiphy_update_from_genl. wiphy_create_complete
is called after all of them, so wiphy.c can be sure it's done with
parsing the wiphy attributes when in prints the new wiphy summary log
message, like it did before manager.c was added.
I had wrongly assumed that all the important wiphy attributes were in
the first message in the dump, but NL80211_ATTR_EXT_FEATURES was not and
wasn't being parsed which was breaking at least testRSSIAgent.
SAE was behaving inconsitently with respect to freeing the state.
It was freeing the SM internally on failure, but requiring netdev
free it on success.
This removes the call to sae_sm_free in sae.c upon failure, and
instead netdev frees the SM in the complete callback in all cases
regardless of success or failure.
From netdev's prospective FILS works the same as OWE/SAE where we create
a fils_sm and forward all auth/assoc frames into the FILS module. The
only real difference is we do not start EAPoL once FILS completes.
FILS (Fast Initial Link Setup) allows a station to negotiate a PTK during
authentication and association. This allows for a faster connection as
opposed to doing full EAP and the 4-way. FILS uses ERP (EAP Reauth Protocol)
to achieve this, but encapsulates the ERP data into an IE inside
authenticate frames. Association is then used to verify both sides have
valid keys, as well as delivering the GTK/IGTK.
FILS will work similar to SAE/OWE/FT where netdev registers a fils_sm, and
then forwards all Auth/Assoc frame data to and from the FILS module.
Keeping the ERP cache on the handshake object allows station.c to
handle all the ERP details and encapsulate them into a handshake.
FILS can then use the ERP cache right from the handshake rather
than getting it itself.
wiphy_select_akm needed to be updated to take a flag, which can be
set to true if there are known reauth keys for this connection. If
we have reauth keys, and FILS is available we will choose it.
If the AP send an associate with an unsupported group status, OWE
was completely starting over and sending out an authenticate frame
when it could instead just resend the associate frame with a
different group.
With FILS support coming there needs to be a way to set the PTK directly.
Other AKMs derive the PTK via the 4-way handshake, but FILS computes the
PTK on its own.
This reverts commit 1e337259ce.
Using util_get_username was wrong in this context. MSCHAPv2 expects us
to only strip the domain name from identities of the form
domain\identity. util_get_username would also strip identities of the
form username@domain.com.
FILS-SHA384 got overlooked and the kek length was being hard coded
to 32 bytes when encrypting the key data. There was also one occurence
where the kek_len was just being set incorrectly.
If the input length is 16 bytes, this means aes_siv_decrypt should
only be verifying the 16 byte SIV and not decrypting any data. If
this is the case, we can skip over the whole AES-CTR portion of
AES-SIV and only verify the SIV.
In eapol_key_handle, 'have_snonce' is checked before decrypting the
key data. For FILS, there will be no snonce so this check can be
skipped if mic_len == 0.
The GTK handshake for FILS uses AES-SIV to encrypt the key data, and
does away with the MIC completely. Now, when finalizing the 2/2 GTK
packet we check the MIC length, and if zero we assume FILS is being
used and we use AES-SIV to encrypt the key data.
For FILS, there is no actual data being encrypted for GTK 2/2 (hence
why the input data length is zero). This results in only the SIV
being generated, which essentially serves the same purpose as a MIC.
FILS does not use a MIC, as well as requires encrypted data on GTK 2/2.
This updates eapol_create_gtk_2_of_2 to pass in extra data to
eapol_create_common, which will reserve room for this encrypted data.
Extra data is only reserved if mic_len == 0.
FILS does not use a MIC in EAPoL frames and also requires encrypted
data on all EAPoL frames. In the common builder the mic_len is now
checked and the flags are set appropriately.
FILS authentication does away with the MIC, so checking for key_mic
in the eapol key frame does not allow FILS to work. Now we pass in
the mic_len to eapol_verify_gtk_1_of_2, and if it is non-zero we can
check that the MIC is present in the frame.
FILS does not require an eapol_sm for authentication, but rekeys
are still performed using the 4-way handshake. Because of this
FILS needs to create a eapol_sm in a 'started' state, but without
calling eapol_start as this will initialize EAP and create handshake
timeouts.
This allows EAPoL to wait for any 4-way packets, and handle them
as rekeys.
ERP (EAP Reauthentication Protocol) allows a station to quickly
reauthenticate using keys from a previous EAP authentication.
This change both implements ERP as well as moves the key cache into
the ERP module.
ERP in its current form is here to only support FILS. ERP is likely not
widespread and there is no easy way to determine if an AP supports ERP
without trying it. Attempting ERP with a non-ERP enabled AP will actually
result in longer connection times since ERP must fail and then full EAP
is done afterwards. For this reason ERP was separated from EAP and a
separate ERP state machine must be created. As it stands now, ERP cannot
be used on its own, only with FILS.
Quick scan uses a set of frequencies associated with the
known networks. This allows to reduce the scan latency.
At this time, the frequency selection follows a very simple
logic by taking all known frequencies from the top 5 most
recently connected networks.
If connection isn't established after the quick scan attempt,
we fall back to the full periodic scan.
Instead of handling NEW_WIPHY events and WIHPY_DUMP events in a similar
fashion, split up the paths to optimize iwd startup time. There's
fundamentally no reason to wait a second (and eat up file-descriptor
resources for timers unnecessarily) when we can simply start an
interface dump right after the wiphy dump.
In case a new wiphy is added in the middle of a wiphy dump, we will
likely get a new wiphy event anyway, in which case a setup_timeout will
be created and we will ignore this phy during the interface dump
processing.
This also optimizes the case of iwd being re-started, in which case
there are no interfaces present.
Separate out the two types of NEW_WIPHY handlers into separate paths and
factor out the common code into a utility function.
Dumps of CMD_NEW_WIPHY can be split up over several messages, while
CMD_NEW_WIPHY events (generated when a new card is plugged in) are
stuffed into a single message.
This also prepares ground for follow-on commits where we will handle the
two types of events differently.
src/netdev.c:netdev_create_from_genl() Skipping duplicate netdev wlp2s0[3]
Aborting (signal 11) [/home/denkenz/iwd/src/iwd]
++++++++ backtrace ++++++++
#0 0x7fc4c7a4e930 in /lib64/libc.so.6
#1 0x40ea13 in netdev_getlink_cb() at src/netdev.c:4654
#2 0x468cab in process_message() at ell/netlink.c:183
#3 0x4690a3 in can_read_data() at ell/netlink.c:289
#4 0x46681d in io_callback() at ell/io.c:126
#5 0x4651cd in l_main_iterate() at ell/main.c:473
#6 0x46530e in l_main_run() at ell/main.c:516
#7 0x465626 in l_main_run_with_signal() at ell/main.c:642
#8 0x403df8 in main() at src/main.c:513
#9 0x7fc4c7a39bde in /lib64/libc.so.6
Mirror netdev.c white/blacklist logic. If either or both the whitelist
and the blacklist are given also fall back to not touching the existing
interface setup on the wiphy.
If we get an error during DEL_INTERFACE or NEW_INTERFACE we may be
dealing with a driver that doesn't implement virtual interfaces or
doesn't implement deleting the default interface. In this case fall
back to using the first usable interface that we've detected on this
wiphy.
There's at least one full-mac driver that doesn't implement the cfg80211
.del_virtual_intf and .add_virtual_intf methods and at least one that
only allows P2P interfaces to be manipulated. mac80211 drivers seem to
at least implement those methods but I didn't check to see if there are
driver where they'd eventually return EOPNOTSUPP.
This is probably the trickiest part in this patchset. I'm introducing a
new logic where instead of using the interfaces that we find present
when a wiphy is detected, which would normally be the one default
interface per wiphy but could be 0 or more than one, we create one
ourselves with the socket owner attribute and use exactly one for
Station, AP and Ad-Hoc modes. When IWD starts we delete all the
interfaces on existing wiphys that we're going to use (as determined by
the wiphy white/blacklists) or freshly hotplugged ones, and only then we
register the interface we're going to use meaning that the wiphy's
limits on the number of concurrent interfaces of each type should be at
0. Otherwise we'd be unlikely to be abe to create the station interface
as most adapters only allow one. After that we ignore any interfaces
that may be created by other processes as we have no use for multiple
station interfaces.
At this point manager.c only keeps local state for wiphys during
the interface setup although when we start adding P2P code we will be
creating and removing interfaces multiple times during the wiphy's
runtime and may need to track it here or in wiphy.c. We do not
specifically check the interface number limits received during the wiphy
dump, if we need to create any interfaces and we're over the driver's
maximum for that specific iftype we'll still attempt it and report error
if it fails.
I tested this and it seems to work with my laptop's intel card and some
USB hotplug adapters.
The latest refactoring ended up assuming that FT related elements would
be handled in netdev_associate_event. However, FullMac cards (that do
not generate netdev_associate_event) could still connect using FT AKMs
and perform the Initial mobility association. In such cases the FTE
element was required but ended up not being set into the handshake.
This caused the handshake to fail during PTK 1_of_4 processing.
Fix this by making sure that FTE + related info is set into the
handshake, albeit with a lower sanity checking level since the
elements have been processed by the firmware already.
Note that it is currently impossible for actual FTs to be performed on
FullMac cards, so the extra logic and sanity checking to handle these
can be skipped.
Add functionality to read and parse the known frequencies
from permanent storage on start of the service. On service
shutdown, we sync the known frequencies back to the permanent
storage.
Each known network (previously connected) will have a set
of known frequencies associated with it, e.g. a set of
frequencies from all BSSs observed. The list of known
frequencies is sorted with the most recently observed
frequency in the head.
Previously, the scan results were disregarded once the new
ones were available. To enable the scan scenarios where the
new scan results are delivered in parts, we introduce a
concept of aging BSSs and will remove them based on
retention time.
Add manager.c, a new file where the wiphy and interface creation/removal
will be handled and interface use policies will be implemented. Since
not all kernel-side nl80211 interfaces are tied to kernel-side netdevs,
netdev.c can't manage all of the interfaces that we will be using, so
the logic is being moved to a common place where all interfaces on a
wiphy will be managed according to the policy, device support for things
like P2P and user enabling/disabling/connecting with P2P which require
interfaces to be dynamically added and removed.
Add wiphy_create, wiphy_update_from_genl and wiphy_destroy that together
will let a new file command the wiphy creation, updates and deletion
with the same functionality the current config notification handler
implements in wiphy.c.
As mentioned in code comments the name is NUL-terminated so there's no
need to return the length path, which was ignored in some occasions
anyway. Consistently treat it as NUL-terminated but also validate.
Make netdev_create_from_genl public and change signature to return the
created netdev or NULL. Also add netdev_destroy that destroys and
unregisters the created netdevs. Both will be used to move the
whole interface management to a new file.
The handshake_state only holds a single AKM value. FILS depends on the AP
supporting EAP as well as FILS. The first time IWD connects, it will do a
full EAP auth. Subsequent connections (assuming FILS is supported) will use
FILS. But if the AP does not support FILS there is no reason to cache the
ERP keys.
This adds the supp_fils to the handshake_state. Now, station.c can set this
flag while building the handshake. This flag can later be checked when
caching the ERP keys.
This allows IWD to cache ERP keys after a full EAP run. Caching
allows IWD to quickly connect to the network later on using ERP or
FILS.
The cache will contain the EAP Identity, Session ID, EMSK, SSID and
optionally the ERP domain. For the time being, the cache entry
lifetimes are hard coded to 24 hours. Eventually the cache should
be written to disk to allow ERP/FILS to work after a reboot or
IWD restart.
mschaputil already had similar functionality, but ERP will need this
as well. These two functions will also handle identities with either
'@' or '\' to separate the user and domain.
Many operations performed during an error in load_settings were the same
as the ones performed when freeing the eap object. Add eap_free_common
to unify these.
EAP identites are recommended to follow RFC 4282 (The Network Access
Identifier). This RFC recommends a maximum NAI length of 253 octets.
It also mentions that RADIUS is only able to support NAIs of 253
octets.
Because of this, IWD should not allow EAP identities larger than 253
bytes. This change adds a check in eap_load_settings to verify the
identity does not exceed this limit.
The associate event is only important for OWE and FT. If neither of
these conditions (or FT initial association) are happening we do
not need to continue further processing the associate event.
802.11 mandates that IEs inside management frames are presented in a
given order. However, in the real world, many APs seem to ignore the
rules and send their IEs in seemingly arbitrary order, especially when
it comes to VENDOR tags. Change this function to no longer be strict in
enforcing the order.
Also, drop checking of rules specific to Probe Responses. These will
have to be handled separately (most likely by the AP module) since
802.11-2016, Section 11.1.4.3.5 essentially allows just about anything.
In netdev_associate_event the ignore_connect_event was getting set true,
but afterwards there were still potential failure paths. Now, once in
assoc_failed we explicitly set ignore_connect_event to false so the
the failure can be handled properly inside netdev_connect_event
The list of PSK/8021x AKM's in security_determine was getting long,
and difficult to keep under 80 characters. This moves them all into
two new macros, AKM_IS_PSK/AKM_IS_8021X.
It was assumed that the hunt-and-peck loop was guarenteed to find
a PWE. This was incorrect in terms of kernel support. If a system
does not have support for AF_ALG or runs out of file descriptors
the KDFs may fail. The loop continued to run if found == false,
which is also incorrect because we want to stop after 20 iterations
regarless of success.
This changes the loop to a for loop so it will always exit after
the set number of iterations.
CC src/scan.o
src/scan.c: In function ‘scan_bss_compute_rank’:
src/scan.c:1048:4: warning: this decimal constant is unsigned only in ISO C90
factor = factor * data_rate / 2340000000 +
The auto-connect state will now consist of the two phases:
STATION_STATE_AUTOCONNECT_QUICK and STATION_STATE_AUTOCONNECT_FULL.
The auto-connect will always start with STATION_STATE_AUTOCONNECT_QUICK
and then transition into STATION_STATE_AUTOCONNECT_FULL if no
connection has been established. During STATION_STATE_AUTOCONNECT_QUICK
phase we take advantage of the wireless scans with the limited number
of channels on which the known networks have been observed before.
This approach allows to shorten the time required for the network
sweeps, therefore decreases the connection latency if the connection
is possible. Thereafter, if no connection has been established after
the first phase we transition into STATION_STATE_AUTOCONNECT_FULL and
do the periodic scan just like we did before the split in
STATION_STATE_AUTOCONNECT state.
For simplicity 160Mhz and 80+80Mhz were grouped together when
parsing the VHT capabilities, but the 80+80 bits were left in
vht_widht_map. This could cause an overflow when getting the
width map.
wiphy_select_akm will now check if BIP is supported, and if MFPR is
set in the scan_bss before returning either SAE AKMs. This will allow
fallback to another PSK AKM (e.g. hybrid APs) if any of the requirements
are not met.
Replace existing uses of memset to clear secrets with explicit_bzero to
make sure it doesn't get optimized away. This has some side effects as
documented in gcc docs but is still recommended.
In eap_secret_info_free make sure we clear both strings in the case of
EAP_SECRET_REMOTE_USER_PASSWORD secrets.
Environments with several AP's, all at low signal strength may
want to lower the roaming RSSI threshold to prevent IWD from
roaming excessively. This adds an option 'roam_rssi_threshold',
which is still defaulted to -70.
Also printing keys with l_debug conditional on an environment variable
as someone wanting debug logs, or leaving debug on accidentally, does
not necessarily want the keys in the logs and in memory.
At some point the connect command builder was modified, and the
control port over NL80211 check was moved to inside if (is_rsn).
For WPS, no supplicant_ie was set, so CONTROL_PORT_OVER_NL80211
was never set into CMD_CONNECT. This caused IWD to expect WPS
frames over netlink, but the kernel was sending them over the
legacy route.
This commit hardens the iwd.service.in template file for systemd
services. The following is a short explanation for each added directive:
+PrivateTmp=true
If true, sets up a new file system namespace for the executed processes
and mounts private /tmp and /var/tmp directories inside it that is not
shared by processes outside of the namespace.
+NoNewPrivileges=true
If true, ensures that the service process and all its children can never
gain new privileges through execve() (e.g. via setuid or setgid bits, or
filesystem capabilities).
+PrivateDevices=true
If true, sets up a new /dev mount for the executed processes and only
adds API pseudo devices such as /dev/null, /dev/zero or /dev/random (as
well as the pseudo TTY subsystem) to it, but no physical devices such as
/dev/sda, system memory /dev/mem, system ports /dev/port and others.
+ProtectHome=yes
If true, the directories /home, /root and /run/user are made
inaccessible and empty for processes invoked by this unit.
+ProtectSystem=strict
If set to "strict" the entire file system hierarchy is mounted
read-only, except for the API file system subtrees /dev, /proc and /sys
(protect these directories using PrivateDevices=,
ProtectKernelTunables=, ProtectControlGroups=).
+ReadWritePaths=/var/lib/iwd/
Sets up a new file system namespace for executed processes. These
options may be used to limit access a process might have to the file
system hierarchy. Each setting takes a space-separated list of paths
relative to the host's root directory (i.e. the system running the
service manager). Note that if paths contain symlinks, they are resolved
relative to the root directory set with RootDirectory=/RootImage=.
Paths listed in ReadWritePaths= are accessible from within
the namespace with the same access modes as from outside of
it.
+ProtectControlGroups=yes
If true, the Linux Control Groups (cgroups(7)) hierarchies accessible
through /sys/fs/cgroup will be made read-only to all processes of the
unit.
+ProtectKernelModules=yes
If true, explicit module loading will be denied. This allows module
load and unload operations to be turned off on modular kernels.
For further explanation to all directives see `man systemd.directives`
Hostapd has now been updated to include the group number when rejecting
the connection with UNSUPP_FINITE_CYCLIC_GROUP. We still need the existing
len == 0 check because old hostapd versions will still behave this way.
The single-use password is apparently sent in plaintext over the network
but at least try to prevent it from staying in the memory until we know
it's been used.
station.c generates the IEs we will need to use for the
Authenticate/Associate and EAPoL frames and sets them into the
handshake_state object. However the driver may modify some of them
during CMD_CONNECT and we need to use those update values so the AP
isn't confused about differing IEs in diffent frames from us.
Specifically the "wl" driver seems to do this at least for the RSN IE.
The KDF function processes data in 32 byte chunks so for groups which
primes are not divisible by 32 bytes, you will get a buffer overflow
when copying the last chunk of data.
Now l_checksum_get_digest is limited to the bytes remaining in the
buffer, or 32, whichever is the smallest.
Since eapol_encrypt_key_data already calculates the key data length and
encodes it into the key frame, we can just return this length and avoid
having to obtain it again from the frame.
Similar to SAE, EAP-PWD derives an ECC point (PWE). It is possible
for information to be gathered from the timing of this derivation,
which could be used to to recover the password.
This change adapts EAP-PWD to use the same mitigation technique as
SAE where we continue to derive ECC points even after we have found
a valid point. This derivation loop continues for a set number of
iterations (20 in this case), so anyone timing it will always see
the same timings for every run of the protocol.
This is not used by any of the scan notify callback implementations and
for P2P we're going to need to scan on an interface without an ifindex
so without this the other changes should be mostly contained in scan.
Also add a mask parameter to wiphy_get_supported_iftypes to make sure
the SupportedModes property only contains the values that can be used
as Device.Mode.
dbus_iftype_to_string returns NULL for unknown iftypes, the strdup will
also return NULL and ret[i] will be assigned a NULL. As a result
the l_strjoinv will not print the known iftypes that might have come
after that and will the l_strfreev will leak the strduped strings.
sc->state would get set when the TRIGGERED event arrived or when the
triggered callback for our own SCAN_TRIGGER command is received.
However it would not get reset to NOT_RUNNING when the NEW_SCAN_RESULTS
event is received, instead we'd first request the results with GET_SCAN
and only reset sc->state when that returns. If during that command a
new scan gets triggered, the GET_SCAN callback would still reset
sc->state and clobber the value set by the new scan.
To fix that repurpose sc->state to only track that period from the
TRIGGERED signal to the NEW_SCAN_RESULTS signal. sc->triggered can be
used to check if we're still waiting for the GET_SCAN command and
sc->start_cmd_id to check if we're waiting for the scan to get
triggered, so one of these three variables will now always indicate if
a scan is in progress.
We can crash if we abort the connection, but the connect command has
already gone through. In this case we will get a sequence of
authenticate_event, associate_event, connect_event. The first and last
events don't crash since they check whether netdev->connected is true.
However, this causes an annoying warning to be printed.
Fix this by introducing an 'aborting' flag and ignore all connection
related events if it is set.
++++++++ backtrace ++++++++
Now that the OWE failure/retry is handled in netdev, we can catch
all associate error status' inside owe_rx_associate rather than only
catching UNSUPP_FINITE_CYCLIC_GROUP.
Apart from OWE, the association event was disregarded and all association
processing was done in netdev_connect_event. This led to
netdev_connect_event having to handle all the logic of both success and
failure, as well as parsing the association for FT and OWE. Also, without
checking the status code in the associate frame there is the potential
for the kernel to think we are connected even if association failed
(e.g. rogue AP).
This change introduces two flags into netdev, expect_connect_failure and
ignore_connect_event. All the FT processing that was once in
netdev_connect_event has now been moved into netdev_associate_event, as
well as non-FT associate frame processing. The connect event now only
handles failure cases for soft/half MAC cards.
Note: Since fullmac cards rely on the connect event, the eapol_start
and netdev_connect_ok were left in netdev_connect_event. Since neither
auth/assoc events come in on fullmac we shouldn't have any conflict with
the new flags.
Once a connection has completed association, EAPoL is started from
netdev_associate_event (if required) and the ignore_connect_event flag can
be set. This will bypass the connect event.
If a connection has failed during association for whatever reason, we can
set expect_connect_failure, the netdev reason, and the MPDU status code.
This allows netdev_connect_event to both handle the error, and, if required,
send a deauth telling the kernel that we have failed (protecting against the
rogue AP situation).
OWE processing can be completely taken care of inside
netdev_authenticate_event and netdev_associate_event. This removes
the need for OWE specific checks inside netdev_connect_event. We can
now return early out of the connect event if OWE is in progress.
Several Auth/Assoc failure status codes indicate that the connection
failed for reasons such as bandwidth issues, poor channel conditions
etc. These conditions should not result in the BSS being blacklisted
since its likely only a temporary issue and the AP is not actually
"broken" per-se.
This adds support in station.c to temporarily blacklist these BSS's
on a per-network basis. After the connection has completed we clear
out these blacklist entries.
Certain error conditions require that a BSS be blacklisted only for
the duration of the current connection. The existing blacklist
does not allow for this, and since this blacklist is shared between
all interfaces it doesnt make sense to use it for this purpose.
Instead, each network object can contain its own blacklist of
scan_bss elements. New elements can be added with network_blacklist_add.
The blacklist is cleared when the connection completes, either
successfully or not.
Now inside network_bss_select both the per-network blacklist as well as
the global blacklist will be checked before returning a BSS.
Several netdev events benefit from including event data in the callback.
This is similar to how the connect callback works as well. The content
of the event data is documented in netdev.h (netdev_event_func_t).
By including event data for the two disconnect events, we can pass the
reason code to better handle the failure in station.c. Now, inside
station_disconnect_event, we still check if there is a pending connection,
and if so we can call the connect callback directly with HANDSHAKE_FAILED.
Doing it this way unifies the code path into a single switch statment to
handle all failures.
In addition, we pass the RSSI level index as event data to
RSSI_LEVEL_NOTIFY. This removes the need for a getter to be exposed in
netdev.h.
On successful send, scan_send_start(..) used to set msg to NULL,
therefore the further management of the command by the caller was
impossible. This patch removes wrapper around l_genl_family_send()
and lets the callers to take responsibility for the command.
This change cleans up the mess of status vs reason codes. The two
types of codes have already been separated into different enumerations,
but netdev was still treating them the same (with last_status_code).
A new 'event_data' argument was added to the connect callback, which
has a different meaning depending on the result of the connection
(described inside netdev.h, netdev_connect_cb_t). This allows for the
removal of netdev_get_last_status_code since the status or reason
code is now passed via event_data.
Inside the netdev object last_status_code was renamed to last_code, for
the purpose of storing either status or reason. This is only used when
a disconnect needs to be emitted before failing the connection. In all
other cases we just pass the code directly into the connect_cb and do
not store it.
All ocurrences of netdev_connect_failed were updated to use the proper
code depending on the netdev result. Most of these simply changed from
REASON_CODE_UNSPECIFIED to STATUS_CODE_UNSPECIFIED. This was simply for
consistency (both codes have the same value).
netdev_[authenticate|associate]_event's were updated to parse the
status code and, if present, use that if their was a failure rather
than defaulting to UNSPECIFIED.
Even though .check_settings in our EAP method implementations does the
settings validation, .load_settings also has minimum sanity checks to
rule out segfaults if the settings have changed since the last
.check_settings call.
If OWE fails in association there is no reason to send a disconnect
since its already known that we failed. Instead we can directly
call netdev_connect_failed
