In the 11n world, most NICs did A-MPDU receive/transmit offloading but
not A-MSDU offloading. So, the net80211 A-MPDU receive path would just
receive MPDUs, do the reordering bit, pass it up to the rest of
net80211 for crypto decap and then do A-MSDU decap before throwing ethernet
frames up to the rest of the system.
However 11ac and 11ax NICs are increasingly doing A-MSDU offload (and
newer 11ax stuff does socket offload, but hey I don't want to scare people
JUST yet) - so although A-MPDU reordering may be done in the OS, A-MSDUs
look like a normal MPDU. This means that all the MSDUs are actually
faked into a set of MPDUs with matching 802.11 header - the sequence number,
QoS header and any encryption verification bits (like IV) are just copied.
This shows up as MASSIVE packet loss in net80211, cause after the first MPDU
we just toss the rest.
(And don't get me started about ethernet decap with A-MPDU host reordering;
we'll have to cross that bridge for later 11ac and 11ax bits too.)
Anyway, this work changes each A-MPDU reorder slot into an mbufq.
The mbufq is treated as a whole set of frames to pass up to the stack
and reordered/de-duped as a group. The last frame in the reorder list
is checked to see if it's an A-MSDU final frame so any duplicates are
correctly tossed rather than double-received. Other than that, the
rest of the logic is unchanged.
The previous commit did a small subset of this - if there wasn't any reordering
going on then it'd accept the A-MSDUs. This is the rest of the needed work.
This is a no-op for 11n NICs doing A-MPDU reordering but needing software
A-MSDU decap - they aren't tagged as A-MSDU and so any subsequent
frames added to the reorder slot are tossed.
Tested:
* QCA9880 (ath10k/athp) - STA/AP mode;
* RT3593 (if_rsu) - 11n STA+DWDS mode (I'm committing through it rn);
* QCA9380 (if_ath) - STA/AP mode.
This is hopefully a big no-op unless you're running some extra
patches to flip on A-MSDU options in a driver.
802.11n supports sending A-MSDU in A-MPDU. That lets you do things
like pack small frames into an A-MSDU and stuff /those/ into an A-MPDU.
It allows for much more efficient airtime because you're not
wasting time sending small frames - which is still a problem when
doing A-MPDU as there's still per-frame overhead and minimum A-MPDU
density requirements.
It, however, is optional for 802.11n. A lot of stuff doesn't advertise
it (but does it, just wait!); and I know that ath10k does it and my
ath(4) driver work supports it.
Now, 802.11ac makes A-MSDU in A-MPDU something that can happen more
frequently, because even though you can send very large A-MPDUs
(like 1 megabyte and larger) you still have the small frame problem.
So, 802.11ac NICs like ath10k and iwm will support A-MSDU in A-MPDU
out of the box if it's enabled - and you can negotiate it.
So, let's lay down the ground work to enable A-MSDU in A-MPDU.
This will allow hardware like iwn(4) and ath(4) which supports
software A-MSDU but hardware A-MPDU to be more efficient.
Drivers that support A-MSDU in A-MPDU will set TX/RX htcap flags.
Note this is separate from the software A-MSDU encap path; /that/
dictates whether net80211 is doing A-MSDU encapsulation or not.
These HTC flags control negotiation, NOT encapsulation.
Once this negotiation and driver bits are done, hardware like
rtwn(4), run(4), and others will be able to use A-MSDU even without
A-MPDU working; right now FF and A-MSDU aren't even attempted
if you're an 11n node. It's a small hold-over from the initial
A-MPDU work and I know how to fix it, but to flip it on properly
I need to be able to negotiate or ignore A-MSDU in A-MPDU.
Oh and the fun part - some 11ac APs I've tested will quite happily
decap A-MSDU in A-MPDU even though they don't negotiate it when
doing 802.11n. So hey, I know it works - I just want to properly
handle things. :-)
Tested:
* AR9380, STA/AP mode
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
No functional change intended.
When doing AMSDU offload, the driver (for now!) presents 802.11 frames with
the same sequence number and crypto sequence number / IV values up to the stack.
But, this will trip afoul over the sequence number detection.
So drivers now have a way to signify that a frame is part of an offloaded
AMSDU group, so we can just ensure that we pass those frames up to the
stack.
The logic will be a bit messy - the TL;DR will be that if it's part of
the previously seen sequence number then it belongs in the same burst.
But if we get a repeat of the same sequence number (eg we sent an ACK
but the receiver didn't hear it) then we shouldn't be passing those frames
up. So, we can't just say "all subframes go up", we need to track
whether we've seen the end of a burst of frames for the given sequence
number or not, so we know whether to actually pass them up or not.
The first part of doing all of this is to ensure the ieee80211_rx_stats
struct is available in the RX sequence number check path and the
RX ampdu reorder path. So, start by passing the pointer into these
functions to avoid doing another lookup.
The actual support will come in a subsequent commit once I know the
functionality actually works!
ucast/mcast/mgmt HT rate.
- Init global ieee80211_htrateset only once; neither ic_htcaps nor
ic_txstream is changed when device is attached;
- Move global ieee80211_htrateset structure to ieee80211com;
there was a possible data race when more than 1 wireless device is
used simultaneously;
- Discard unsupported rates in ieee80211_ioctl_settxparams(); otherwise,
an unsupported value may break connectivity (actually,
'ifconfig wlan0 ucastrate 8' for RTL8188EU results in immediate
disconnect + infinite 'device timeout's after it).
Tested with:
- Intel 6205, STA mode.
- RTL8821AU, STA mode.
Reviewed by: adrian
Differential Revision: https://reviews.freebsd.org/D9871
This is the bulk of the magic to start enabling VHT channel negotiation.
It is absolutely, positively not yet even a complete VHT wave-1 implementation.
* parse IEs in scan, assoc req/resp, probe req/resp;
* break apart the channel upgrade from the HT IE parsing - do it after the
VHT IEs are parsed;
* (dirty! sigh) add channel width decision making in ieee80211_ht.c htinfo_update_chw().
This is the main bit where negotiated channel promotion through IEs occur.
* Shoehorn in VHT node init ,teardown, rate control, etc calls like the HT
versions;
* Do VHT channel adjustment where appropriate
Tested:
* monitor mode, ath10k port
* STA mode, ath10k port - VHT20, VHT40, VHT80 modes
TODO:
* IBSS;
* hostap;
* (ignore mesh, wds for now);
* finish 11n state engine - channel width change, opmode notifications, SMPS, etc;
* VHT basic rate negotiation and acceptance criteria when scanning, associating, etc;
* VHT control/management frame handling (group managment and operating mode being
the two big ones);
* Verify TX/RX VHT rate negotiation is actually working correctly.
Whilst here, add some comments about seqno allocation and locking. To achieve
the full VHT rates I need to push seqno allocation into the drivers and
finally remove the IEEE80211_TX_LOCK() I added years ago to fix issues. :/
Unfortunately (sigh) some firmware doesn't provide the RX BA starting point,
so we need to cope and set a "close enough" sequence number so we (hopefully!)
don't discard frames as duplicates.
Tested:
* QCA9880v2, athp driver (under development), STA mode
IBSS negotiation is a subset of the STA/AP negotiation. We always have a
current channel, so base the HT capabilities on the current channel.
This is then put into IBSS probe requests to inform peers of our
11n capabilities.
A-MSDU is another 11n aggregation mechanism where multiple ethernet
frames get LLC encapsulated (so they have a length field), padded,
and put in a single MPDU (802.11 MAC frame.) This means it gets sent
out as a single frame, with a single seqno, it's acked as one frame, etc.
It turns out that, hah, atheros fast frames is almost but not quite
like this, so I'm reusing all of the current superg/fast-frames stuff
in order to actually transmit A-MSDU. Yes, this means that A-MSDU
frames are also only aggregated two at a time, so it's not necessarily
a huge win, but it's better than nothing.
This doesn't do anything by default - the driver needs to say it does
A-MSDU as well as set the AMSDU software TX capability so this code path
gets exercised.
For now, the only driver that enables this is urtwn. I'll enable it
for rsu at some point soon.
Tested:
* Add an amsdu encap path to aggregate two frames, same as the
fast-frames path.
* Always do the superg init/teardown and node init/teardown stuff,
regardless of whether the nodes are doing fast-frames (the ATH
capability stuff.) That way we can reuse it for amsdu.
* Don't do AMSDU for multicast/broadcast and EAPOL frames.
* If we're doing A-MPDU, then don't bother doing FF/A-MSDU.
We can likely do both together, but I don't want to change
behaviour.
* Teach the fast frames approx txtime logic to support the 11n
rates. But, since we don't currently have a full "current rate"
support, assume it's HT20, long-gi, etc. That way we overshoot
on the TX time estimation, so we're always inside the requirements.
(And we only aggregate two frames for now, so we're not really
going to exceed that.)
* Drop the maximum FF age default down to 2ms, otherwise we end up
with some very annoyingly large latencies.
TODO:
* We only aggregate two ethernet frames, so I'm not checking the max
A-MSDU size. But when it comes time to support >2 frames, we should
obey that.
Tested:
* urtwn(4)
in the superg fast-frames code.
This harks back to an earlier commit (r280349) where I found that
initialising the pps code with ticks=0 would cause hilariously bad
hz ticks wraparound failures, leading to never actually aggregating
traffic. This is still true for the superg path and so I have to
do the same thing there.
This is a big no-op; a subsequent commit will flip this on so it
works with the fast-frames transmit path.
Tested:
* AR9170, otus(4) - STA mode, 11bg operation
* AR9331, AP mode
Some fullmac devices may rely on the stack starting it but not doing it.
Whilst here, remove a duplicate LE_* macro definition, thanks to
Andriy Voskoboinyk <s3erios@gmail.com>.
for re-ordering.
Devices like if_rsu don't pass through action/management frames but do send
firmware commands to inform us of things. One of those notifications is
the RX A-MPDU negotiated parameters.
Currently, a channel width change updates the 802.11n HT info data in
net80211 but it doesn't trigger any device changes. So the device
driver may decide that HT40 frames can be transmitted but the last
device channel set only had HT20 set.
Now, a task is scheduled so a hardware reset or change isn't done
during any active ongoing RX. It also means that it's serialised
with the other task operations (eg channel change.)
This isn't the final incantation of this work, see below.
For now, any unmodified drivers will simply receive a channel
change log entry. A subsequent patch to ath(4) will introduce
some basic channel change handling (by resetting the NIC.)
Other NICs may need to update their rate control information.
TODO:
* There's still a small window at the present moment where the
channel width has been updated but the task hasn't been fired.
The final version of this should likely pass in a channel width
field to the driver and let the driver atomically do whatever
it needs to before changing the channel.
PR: kern/166286
adjust the IEEE80211_HTRATE_MAXSIZE constant, only MCS0 - 76 are valid
the other bits in the mcsset IE (77 - 127) are either reserved or used
for TX parameters.
o add a new facility for components to register send+recv handlers
o ieee80211_send_action and ieee80211_recv_action now use the registered
handlers to dispatch operations
o rev ieee80211_send_action api to enable passing arbitrary data
o rev ieee80211_recv_action api to pass the 802.11 frame header as it may
be difficult to locate
o update existing IEEE80211_ACTION_CAT_BA and IEEE80211_ACTION_CAT_HT handling
o update mwl for api rev
Reviewed by: rpaulo
Approved by: re (kensmith)
o correct BAR frame construction for AMPDU
o retransmit BAR frames until ACK'd or timeout (use tunables to
control behaviour, default is very aggressive)
o defer seq# update until BAR frame is ACK'd
o add BAR response handling callback for driver to interpose and
push new state to device or push pending aggregates
While here also:
o add backpointer to node in the per-tid tx aggregation data structure
o move ampdu tx state setup/teardown work to separate functions
o change ieee80211_parse_htcap and ieee80211_parse_htinfo to save only
internal state obtained from the ie's; no dynamic state such as
ni_chw is altered
o add ieee80211_ht_updateparams to parse ht cap+info ie's and update
dynamic node state
o change ieee80211_ht_node_init to not take an htcap ie that is parsed;
instead have the caller make a separate call as one caller wants to
parse the ie while another wants to parse both cap+info ie's and
update state so can better do this with ieee80211_ht_updateparams
These changes fix sta mode state handling where the node's channel
width was shifted to ht20/ht40 prematurely.
o use txa_start to form the addba request and purge txa_seqstart
o fill txa_start before calling ic_addba_request to permit drivers
to override when they handle seq# generation (e.g. mwl)
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)
o add driver callback to handle notification of beacon changes;
this is required for devices that manage beacon frames themselves
(devices must override the default handler which does nothing)
o move beacon update-related flags from ieee80211com to the beacon
offsets storage (or handle however a driver wants)
o expand beacon offsets structure with members needed for 11h/dfs
and appie's
o change calling convention for ieee80211_beacon_alloc and
ieee80211_beacon_update
o add overlapping bss support for 11g; requires driver to pass
beacon frames from overlapping bss up to net80211 which is not
presently done by any driver
o move HT beacon contents update to a routine in the HT code area
Reviewed by: avatar, thompsa, sephe
Approved by: re (blanket wireless)
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.
