channel list ends up with 2 entries, the HT and the legacy channel.
The scan itself is currently always done at legacy rates so we end
up receiving scan results for legacy networks on the HT channel and
erroneously assigning the BSS to the 11n channel. As the channel's
capabilities are used to setup the adapter we might end up with
non-working settings and/or firmware crashes.
Fix this by ensuring that scan results received on a HT channel
are only assigned to that channel if the htcap IE is available,
else use the legacy channel equivalent.
Tested by: Pawel Worach, Raoul Megelas, Maciej Milewski,
Andrei <az at azsupport dot com>
Approved by: re (kib)
If multiple networks are available the max bandwidth is one
condition used for selecting the "best" BSS. To achieve that
we should consider all parameters which affect the max RX rate.
This includes 20/40MHz, SGI and the of course the MCS set.
If the TX MCS parameters are available we should use those,
because an AP announcing support for receiving frames at 450Mbps
might only be able to transmit at 150Mbps (1T3R). I haven't seen
devices with support for transmitting at higher rates then
receiving, so prefering TX over RX information should be safe.
While here, remove the hardcoded assumption that MCS15 is the max
possible MCS rate, use MCS31 instead which really is the highest
rate (according to the 802.11n std). Also, fix a mismatch of an
40MHz/SGI check.
beacon or probe-response frames. Fix the condition by checking for the
the array's content instead of the always existing array itself.
Reviewed by: rpaulo, stefanf
MFC after: 3 days
net80211 wireless stack. This work is based on the March 2009 D3.0 draft
standard. This standard is expected to become final next year.
This includes two main net80211 modules, ieee80211_mesh.c
which deals with peer link management, link metric calculation,
routing table control and mesh configuration and ieee80211_hwmp.c
which deals with the actually routing process on the mesh network.
HWMP is the mandatory routing protocol on by the mesh standard, but
others, such as RA-OLSR, can be implemented.
Authentication and encryption are not implemented.
There are several scripts under tools/tools/net80211/scripts that can be
used to test different mesh network topologies and they also teach you
how to setup a mesh vap (for the impatient: ifconfig wlan0 create
wlandev ... wlanmode mesh).
A new build option is available: IEEE80211_SUPPORT_MESH and it's enabled
by default on GENERIC kernels for i386, amd64, sparc64 and pc98.
Drivers that support mesh networks right now are: ath, ral and mwl.
More information at: http://wiki.freebsd.org/WifiMesh
Please note that this work is experimental. Also, please note that
bridging a mesh vap with another network interface is not yet supported.
Many thanks to the FreeBSD Foundation for sponsoring this project and to
Sam Leffler for his support.
Also, I would like to thank Gateworks Corporation for sending me a
Cambria board which was used during the development of this project.
Reviewed by: sam
Approved by: re (kensmith)
Obtained from: projects/mesh11s
o replace DLT_IEEE802_11 support in net80211 with DLT_IEEE802_11_RADIO
and remove explicit bpf support from wireless drivers; drivers now
use ieee80211_radiotap_attach to setup shared data structures that
hold the radiotap header for each packet tx/rx
o remove rx timestamp from the rx path; it was used only by the tdma support
for debugging and was mostly useless due to it being 32-bits and mostly
unavailable
o track DLT_IEEE80211_RADIO bpf attachments and maintain per-vap and
per-com state when there are active taps
o track the number of monitor mode vaps
o use bpf tap and monitor mode vap state to decide when to collect radiotap
state and dispatch frames; drivers no longer explicitly directly check
bpf state or use bpf calls to tap frames
o handle radiotap state updates on channel change in net80211; drivers
should not do this (unless they bypass net80211 which is almost always
a mistake)
o update various drivers to be more consistent/correct in handling radiotap
o update ral to include TSF in radiotap'd frames
o add promisc mode callback to wi
Reviewed by: cbzimmer, rpaulo, thompsa
sleepable context for net80211 driver callbacks. This removes the need for USB
and firmware based drivers to roll their own code to defer the chip programming
for state changes, scan requests, channel changes and mcast/promisc updates.
When a driver callback completes the hardware state is now guaranteed to have
been updated and is in sync with net80211 layer.
This nukes around 1300 lines of code from the wireless device drivers making
them more readable and less race prone.
The net80211 layer has been updated as follows
- all state/channel changes are serialised on the taskqueue.
- ieee80211_new_state() always queues and can now be called from any context
- scanning runs from a single taskq function and executes to completion. driver
callbacks are synchronous so the channel, phy mode and rx filters are
guaranteed to be set in hardware before probe request frames are
transmitted.
Help and contributions from Sam Leffler.
Reviewed by: sam
o break out version-related code to simplify rev'ing the protocol
o add parameter validation macros so checks that appear multiple places
are consistent (and easy to change)
o add protocol version check when looking for a scan candidate
o improve scan debug output format
o rewrite beacon update handling to calculate a bitmask of changed values
and pass that down through the driver callback so drivers can optimize work
o do slot bounds check before use when parsing received beacons
and xmit parameters. This makes it possible to use tdma on fractional
channels.
o add IEEE80211_MODE_HALF and IEEE80211_MODE_QUARTER; note these are
band-agnostic (may need revisiting)
o setup all default rates in ic_sup_rates instead of doing it only
for active modes; we need these to calculate the default tx parameters
which are not recalculated after a regulatory update (can't just
recalculate after installing a new channel list because we might
clobber user settings)
o remove special case code in ieee80211_get_suprates; this is now
a candidate for an inline or removal
o add various entries for new modes (roaming+tx params, wme, rate
mapping, scan set setup, country ie construction, tdma, basic rates)
Note these modes are intentionally not visible through if_media.
channel, only accept a real 11g channel; this fixes a problem where we were
wrongly promoting 11b to a Dynamic Turbo G channel which broke scanning on
channel 6
o add net80211 support for a tdma vap that is built on top of the
existing adhoc-demo support
o add tdma scheduling of frame transmission to the ath driver; it's
conceivable other devices might be capable of this too in which case
they can make use of the 802.11 protocol additions etc.
o add minor bits to user tools that need to know: ifconfig to setup and
configure, new statistics in athstats, and new debug mask bits
While the architecture can support >2 slots in a TDMA BSS the current
design is intended (and tested) for only 2 slots.
Sponsored by: Intel
really was meant to be 256. Adjust usage accordingly and replace
bogus usage of this value in checking IEEE channel #'s.
NB: this causes an ABI change; ifconfig must be recompiled
(unless explicitly locked to mode 11b) so when we join the bss the
channel attached to the scan cache entry may need to be demoted.
o demote to 11b if the ap is advertising 11b rates
o skip the ap if it's 11b but we're locked to 11g (could consider this
advisory but for now treat it as mandatory)
o handle an odd edge case, if there is a fixed transmit rate for 11g
then the rate check against the 11b ap will fail, try to demote to
11b and retry the rate check
Reviewed by: sephe, thompsa
Note this includes changes to all drivers and moves some device firmware
loading to use firmware(9) and a separate module (e.g. ral). Also there
no longer are separate wlan_scan* modules; this functionality is now
bundled into the wlan module.
Supported by: Hobnob and Marvell
Reviewed by: many
Obtained from: Atheros (some bits)
while still restricting auto-channel select to only those channels
permitted by regulatory constraints (sorta, we're still missing the
checks to honor radar and noadhoc status on channels). This somehow
got lost in the initial merge of the revised scanning code.
Reviewed by: jhay
MFC after: 2 weeks
sends frames up the stack after changing the current channel then
the lookup by ieee channel number may fail leaving a null ptr in
se_chan; if this happens fallback to the channel recorded when the
frame is processed (curchan). Since the frame doesn't contribute
to scan results for the sta this is acceptable.
Reviewed by: thompsa
MFC after: 3 days
o do not override the home channel recorded for the sta when the frame is
received off-channel; this fixes a problem where we might think the sta
was operating on the channel the frame was received on causing association
requests to be ignored/rejected (likely cause of kern/99036)
o don't include rssi of off-channel frames in the avg rssi used to select
a bss; this gives us a better estimate of the signal we will see for the
station when on-channel
PR: kern/99036
Found by: Yubin Gong
Reviewed by: sephe
MFC after: 1 week
11b channel is not found, e.g. Atheros 5211.
Reported by: matteo
Problem outlined by: thompsa
Reviewed by: sam, thompsa
Approved by: re (kensmith), sam (mentor)
Tested by: matteo (an early version)
operating channel and use this in the scan cache rather than directly using
ic_curchan. Some firmware cards can only do a full scan and so ic_curchan does
not have the correct value.
Also add IEEE80211_CHAN2IEEE to directly dereference ic_ieee from the channel
to be used in the fast path.
Reviewed by: sam, sephe
Approved by: re (kensmith)
o major overhaul of the way channels are handled: channels are now
fully enumerated and uniquely identify the operating characteristics;
these changes are visible to user applications which require changes
o make scanning support independent of the state machine to enable
background scanning and roaming
o move scanning support into loadable modules based on the operating
mode to enable different policies and reduce the memory footprint
on systems w/ constrained resources
o add background scanning in station mode (no support for adhoc/ibss
mode yet)
o significantly speedup sta mode scanning with a variety of techniques
o add roaming support when background scanning is supported; for now
we use a simple algorithm to trigger a roam: we threshold the rssi
and tx rate, if either drops too low we try to roam to a new ap
o add tx fragmentation support
o add first cut at 802.11n support: this code works with forthcoming
drivers but is incomplete; it's included now to establish a baseline
for other drivers to be developed and for user applications
o adjust max_linkhdr et. al. to reflect 802.11 requirements; this eliminates
prepending mbufs for traffic generated locally
o add support for Atheros protocol extensions; mainly the fast frames
encapsulation (note this can be used with any card that can tx+rx
large frames correctly)
o add sta support for ap's that beacon both WPA1+2 support
o change all data types from bsd-style to posix-style
o propagate noise floor data from drivers to net80211 and on to user apps
o correct various issues in the sta mode state machine related to handling
authentication and association failures
o enable the addition of sta mode power save support for drivers that need
net80211 support (not in this commit)
o remove old WI compatibility ioctls (wicontrol is officially dead)
o change the data structures returned for get sta info and get scan
results so future additions will not break user apps
o fixed tx rate is now maintained internally as an ieee rate and not an
index into the rate set; this needs to be extended to deal with
multi-mode operation
o add extended channel specifications to radiotap to enable 11n sniffing
Drivers:
o ath: add support for bg scanning, tx fragmentation, fast frames,
dynamic turbo (lightly tested), 11n (sniffing only and needs
new hal)
o awi: compile tested only
o ndis: lightly tested
o ipw: lightly tested
o iwi: add support for bg scanning (well tested but may have some
rough edges)
o ral, ural, rum: add suppoort for bg scanning, calibrate rssi data
o wi: lightly tested
This work is based on contributions by Atheros, kmacy, sephe, thompsa,
mlaier, kevlo, and others. Much of the scanning work was supported by
Atheros. The 11n work was supported by Marvell.
