Under certain conditions, access points with very low signal could be
detected. This signal is too low to estimate a data rate and causes
this L_WARN to fire. Fix this by returning a -ENETUNREACH error code in
case the signal is too low for any of the supported rates.
Some network settings keys are set / parsed in multiple files. Add a
utility to parse all common network configuration settings in one place.
Also add some defines to make sure settings are always saved in the
expected group/key.
scan_parse_result used to parse the wdev and return this to the caller
where it was compared against the expected wdev. Simplify this by
extract the wdev first, and proceeding with the bss parsing afterwards.
NL80211_BSS_LAST_SEEN_BOOTTIME is expressed in nanoseconds, while BSS
timestamps are expressed in microseconds internally. Convert the
attribute to microseconds when using it to timestamp a BSS. This makes
iwd expire absent BSSes within 30 seconds as intended.
Fixes: 454cee12d4 ("scan: Use kernel-reported time-stamp if provided")
It was observed that IWD's ranking for BSS's did not always
end up with the fastest being chosen. This was due to IWD's
heavy weight on signal strength. This is a decent way of ranking
but even better is calculating a theoretical data rate which
was also done and factored in. The problem is the data rate
factor was always outdone by the signal strength.
Intead remove signal strength entirely as this is already taken
into account with the data rate calculation. This also removes
the check for rate IEs. If no IEs are found the parser will
base the data rate soley on RSSI.
There were a few other factors removed which will be added back
when ranking *networks* rather than BSS's. WPA version (or open)
was removed as well as the privacy capability. These values really
should not differ between BSS's in the same SSID and as such
should be used for network ranking instead.
Adds support for getting firmware scan results from the kernel.
This is intended to be used after the firmware roamed automatically
and the scan result is require for handshake initialization.
The scan 'request' is competely separate from the normal scan
queue, though scan_results, scan_request, and the scan_context
are all used for consistency and code reuse.
Handle situations where the BSS we're trying to connect to is no longer
in the kernel scan result cache. Normally, the kernel will re-scan the
target frequency if this happens on the CMD_CONNECT path, and retry the
connection.
Unfortunately, CMD_AUTHENTICATE path used for WPA3, OWE and FILS does
not have this scanning behavior. CMD_AUTHENTICATE simply fails with
a -ENOENT error. Work around this by trying a limited scan of the
target frequency and re-trying CMD_AUTHENTICATE once.
Found using lsan:
==29896==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 9 byte(s) in 1 object(s) allocated from:
#0 0x7fcd41e0c710 in __interceptor_malloc /var/tmp/portage/sys-devel/gcc-8.2.0-r6/work/gcc-8.2.0/libsanitizer/asan/asan_malloc_linux.cc:86
#1 0x606abd in l_malloc ell/util.c:62
#2 0x460230 in ie_tlv_vendor_ie_concat src/ie.c:140
#3 0x4605d1 in ie_tlv_extract_wfd_payload src/ie.c:216
#4 0x4a8773 in scan_parse_bss_information_elements src/scan.c:1105
#5 0x4a94a8 in scan_parse_attr_bss src/scan.c:1181
#6 0x4a99f8 in scan_parse_result src/scan.c:1238
#7 0x4abe4e in get_scan_callback src/scan.c:1451
#8 0x6442d9 in process_unicast ell/genl.c:979
#9 0x6453ff in received_data ell/genl.c:1087
#10 0x62e1a4 in io_callback ell/io.c:126
#11 0x628fca in l_main_iterate ell/main.c:473
#12 0x6294e8 in l_main_run ell/main.c:520
#13 0x629d8b in l_main_run_with_signal ell/main.c:642
#14 0x40681b in main src/main.c:505
#15 0x7fcd40a55bdd in __libc_start_main (/lib64/libc.so.6+0x21bdd)
Besides being undefined behaviour, signed integer overflow can cause
unexpected comparison results. In the case of network_rank_compare(),
a connected network with rank INT_MAX would cause newly inserted
networks with negative rank to be inserted earlier in the ordered
network list. This is reflected in the GetOrderedMethods() DBus method
as can be seen in the following iwctl output:
[iwd]# station wlan0 get-networks
Network name Security Signal
----------------------------------------------------
BEOLAN 8021x **** }
BeoBlue psk *** } all unknown,
UI_Test_Network psk *** } hence assigned
deneb_2G psk *** } negative rank
BEOGUEST open **** }
> titan psk ****
Linksys05274_5GHz_dmt psk ****
Lyngby-4G-4 5GHz psk ****
Instead of creating the results->bss_list l_queue lazily, always create
one before sending the GET_SCAN command. This is to make sure that an
empty list is passed to the scan callback (e.g. in station.c) instead of
a NULL. Passing NULL has been causing difficult to debug crashes in
station.c, in fact I think I've been seeing them for over a year now
but can't be sure. station_set_scan_results has been taking ownership
of the new BSS list and, if station->connected_bss was not on the list,
it would try to add it not realizing that l_queue_push_tail() was doing
nothing. Always passing a valid list may help us prevent similar
problems in the future.
The crash might start with:
==120489== Invalid read of size 8
==120489== at 0x425D38: network_bss_select (network.c:709)
==120489== by 0x415BD1: station_try_next_bss (station.c:2263)
==120489== by 0x415E31: station_retry_with_status (station.c:2323)
==120489== by 0x415E31: station_connect_cb (station.c:2367)
==120489== by 0x407E66: netdev_connect_failed (netdev.c:569)
==120489== by 0x40B93D: netdev_connect_event (netdev.c:1801)
==120489== by 0x40B93D: netdev_mlme_notify (netdev.c:3678)
To use the wiphy radio work queue, scanning mostly remained the same.
start_next_scan_request was modified to be used as the work callback,
as well as not start the next scan if the current one was done
(since this is taken care of by wiphy work queue now). All
calls to start_next_scan_request were removed, and more or less
replaced with wiphy_radio_work_done.
scan_{suspend,resume} were both removed since radio management
priorities solve this for us. ANQP requests can be inserted ahead of
scan requests, which accomplishes the same thing.
If start_scan_next_request() is called while a scan request
(NL80211_CMD_TRIGGER_SCAN) is still running, the same scan request will
be sent again. Add a check in the function to avoid sending a request if
one is already in progress. For consistency, check also that scan
results are not being requested (NL80211_CMD_GET_SCAN), before trying to
send the next scan request. Finally, remove similar checks at
start_next_scan_request() callsites to simplify the code.
This also fixes a crash that occurs if the following conditions are met:
- the duplicated request is the only request in the scan request
queue, and
- both scan requests fail with an error not EBUSY.
In this case, the first callback to scan_request_triggered() will delete
the request from the scan request queue. The second callback will find
an empty queue and consequently pass a NULL scan_request pointer to
scan_request_failed(), causing a segmentation fault.
If scanning is suspended, have scan_common() queue its scan request
rather than issuing it immediately. This respects the assumption that
scans are not requested while sc->suspended is true.
#0 0x000055555558ee5d in scan_notify (msg=0x55555560b640, user_data=0x0) at src/scan.c:1706
#1 0x00007ffff7f2c78c in ?? () from /usr/lib/libell.so.0
#2 0x00007ffff7f299ec in ?? () from /usr/lib/libell.so.0
#3 0x00007ffff7f28e4a in l_main_iterate () from /usr/lib/libell.so.0
#4 0x00007ffff7f28efc in l_main_run () from /usr/lib/libell.so.0
#5 0x00007ffff7f290b9 in l_main_run_with_signal () from /usr/lib/libell.so.0
#6 0x00005555555639c4 in main (argc=1, argv=0x7fffffffec18) at src/main.c:497
Save the source frame type in struct scan_bss as it may affect how some
of the data in the struct will be parsed. Also replace the P2P IE
payload data in that struct with a union containing pre-parsed p2p
attributes corresponding to the frame type.
This means users don't have to call the parsers in p2putil.c on that
data, which wouldn't have worked anyway because those parsers assume
input is the raw IE sequence rather than just the "payload".
The kernel sends NL80211_ATTR_SCAN_START_TIME_TSF with CMD_TRIGGER and
RRM requires this value for beacon measurement reports.
The start time is parsed during CMD_TRIGGER and set into the scan request.
A getter was added to obtain this time value for an already triggered
scan.
After making the change, the SCAN_ABORTED case was cleaned up a bit to
remove the local scan_request usage in favor of the one used for all the
other cases.
The kernel allows a scan duration and duration mandatory flag to be
set in scan requests. RRM requests can contain these values so they
have been added to scan_parameters.
Scanning with drivers which do not support EXT_FEATURE_SET_SCAN_DWELL
will not include these values in scan requests.
no_cck_rates is set in the scan parameters generally to make sure
that the Probe Request frames are not sent at any of the 802.11b
rates during active scans. With this patch we also omit those rates
from the Supported Rates IEs, which is required by the p2p spec and
also matches our flag's name.
The intent here was to validate that the frequency is a multiple of 5
and lies in a certain range. Somehow the channel was checked for being
a multiple of 5 instead.
