802.11 mbufs.
The raw transmit path currently doesn't make it easy to queue
these frames:
* there's no node reference stored in the mbuf, like for the normal
path, and
* the bpf supplied raw transmit parameters (rate, rts/cts, etc)
are passed in as an argument, not as an mbuf tag.
In order to support driver queuing of these frames, we need to
be able to put the above into the mbuf before the driver gets it,
so the driver /can/ put it into a queue if needed.
Use an mbuf tag and for now just verbatim copy the bpf parameters
into it. Later on it may grow to include more options but this
will do for now.
Why would you want to queue raw frames? Well, in the case of
iwn(4), we can't send the firmware frames to transmit before
we hear a beacon - the firmware will consider passive channels
as unavailable until it hears a beacon. The firmware "passive"
channel state is cleared upon each RXON command, which is sent to
update association status. So, when we attempt association and
authorisation, the RXON command causes the firmware to clear out
what it's already seen, and so we have to wait for a beacon before
we can transmit.
Before people get overly excited - this alone doesn't "fix" 5GHz
operation - it just makes it (more) possible.
The aim here is to convert all the drivers over to use a raw_xmit()
API that doesn't include the node and params - instead they'd get
those from the mbuf. Then raw_xmit() becomes just a side-channel
version of the normal transmit path for management traffic.
MFC after: 2 weeks
Sponsored by: Norse Corp, Inc.
DragonflyBSD uses the FreeBSD wireless stack and drivers. Their malloc()
API is named differently, so they don't have userland/kernel symbol
clashes like we do (think libuinet.)
So, to make it easier for them and to port to other BSDs/other operating
systems, start hiding the malloc specific bits behind defines in
ieee80211_freebsd.h.
DragonflyBSD can now put these portability defines in their local
ieee80211_dragonflybsd.h.
This should be a great big no-op for everyone running wifi.
TODO:
* kill M_WAITOK - some platforms just don't want you to use it
* .. and/or handle it returning NULL rather than waiting forever.
* MALLOC_DEFINE() ?
* Migrate the well-known malloc names (eg M_TEMP) to net80211
namespace defines.
together.
Add M_FLAG_PRINTF for use with printf(9) %b indentifier.
Use the generic mbuf flags print names in the net80211 code and adjust
the protocol specific bits for their new positions.
Change SCTP M_PROTO mapping from 5 to 1 to fit within the 16bit field
they use internally to store some additional information.
Discussed with: trociny, glebius
M_LASTFRAG flags to protocol specific flags.
Remove the now unused M_FRAG, M_FIRSTFRAG and M_LASTFRAG mbuf flags.
Discussed with: trociny, glebius, adrian
upper layer(s).
This eliminates the if_snd queue from net80211. Yay!
This unfortunately has a few side effects:
* It breaks ALTQ to net80211 for now - sorry everyone, but fixing
parallelism and eliminating the if_snd queue is more important
than supporting this broken traffic scheduling model. :-)
* There's no VAP and IC flush methods just yet - I think I'll add
some NULL methods for now just as placeholders.
* It reduces throughput a little because now net80211 will drop packets
rather than buffer them if the driver doesn't do its own buffering.
This will be addressed in the future as I implement per-node software
queues.
Tested:
* ath(4) and iwn(4) in STA operation
This patchset implements a new TX lock, covering both the per-VAP (and
thus per-node) TX locking and the serialisation through to the underlying
physical device.
This implements the hard requirement that frames to the underlying physical
device are scheduled to the underlying device in the same order that they
are processed at the VAP layer. This includes adding extra encapsulation
state (such as sequence numbers and CCMP IV numbers.) Any order mismatch
here will result in dropped packets at the receiver.
There are multiple transmit contexts from the upper protocol layers as well
as the "raw" interface via the management and BPF transmit paths.
All of these need to be correctly serialised or bad behaviour will result
under load.
The specifics:
* add a new TX IC lock - it will eventually just be used for serialisation
to the underlying physical device but for now it's used for both the
VAP encapsulation/serialisation and the physical device dispatch.
This lock is specifically non-recursive.
* Methodize the parent transmit, vap transmit and ic_raw_xmit function
pointers; use lock assertions in the parent/vap transmit routines.
* Add a lock assertion in ieee80211_encap() - the TX lock must be held
here to guarantee sensible behaviour.
* Refactor out the packet sending code from ieee80211_start() - now
ieee80211_start() is just a loop over the ifnet queue and it dispatches
each VAP packet send through ieee80211_start_pkt().
Yes, I will likely rename ieee80211_start_pkt() to something that
better reflects its status as a VAP packet transmit path. More on
that later.
* Add locking around the management and BAR TX sending - to ensure that
encapsulation and TX are done hand-in-hand.
* Add locking in the mesh code - again, to ensure that encapsulation
and mesh transmit are done hand-in-hand.
* Add locking around the power save queue and ageq handling, when
dispatching to the parent interface.
* Add locking around the WDS handoff.
* Add a note in the mesh dispatch code that the TX path needs to be
re-thought-out - right now it's doing a direct parent device transmit
rather than going via the vap layer. It may "work", but it's likely
incorrect (as it bypasses any possible per-node power save and
aggregation handling.)
Why not a per-VAP or per-node lock?
Because in order to ensure per-VAP ordering, we'd have to hold the
VAP lock across parent->if_transmit(). There are a few problems
with this:
* There's some state being setup during each driver transmit - specifically,
the encryption encap / CCMP IV setup. That should eventually be dragged
back into the encapsulation phase but for now it lives in the driver TX path.
This should be locked.
* Two drivers (ath, iwn) re-use the node->ni_txseqs array in order to
allocate sequence numbers when doing transmit aggregation. This should
also be locked.
* Drivers may have multiple frames queued already - so when one calls
if_transmit(), it may end up dispatching multiple frames for different
VAPs/nodes, each needing a different lock when handling that particular
end destination.
So to be "correct" locking-wise, we'd end up needing to grab a VAP or
node lock inside the driver TX path when setting up crypto / AMPDU sequence
numbers, and we may already _have_ a TX lock held - mostly for the same
destination vap/node, but sometimes it'll be for others. That could lead
to LORs and thus deadlocks.
So for now, I'm sticking with an IC TX lock. It has the advantage of
papering over the above and it also has the added advantage that I can
assert that it's being held when doing a parent device transmit.
I'll look at splitting the locks out a bit more later on.
General outstanding net80211 TX path issues / TODO:
* Look into separating out the VAP serialisation and the IC handoff.
It's going to be tricky as parent->if_transmit() doesn't give me the
opportunity to split queuing from driver dispatch. See above.
* Work with monthadar to fix up the mesh transmit path so it doesn't go via
the parent interface when retransmitting frames.
* Push the encryption handling back into the driver, if it's at all
architectually sane to do so. I know it's possible - it's what mac80211
in Linux does.
* Make ieee80211_raw_xmit() queue a frame into VAP or parent queue rather
than doing a short-cut direct into the driver. There are QoS issues
here - you do want your management frames to be encapsulated and pushed
onto the stack sooner than the (large, bursty) amount of data frames
that are queued. But there has to be a saner way to do this.
* Fragments are still broken - drivers need to be upgraded to an if_transmit()
implementation and then fragmentation handling needs to be properly fixed.
Tested:
* STA - AR5416, AR9280, Intel 5300 abgn wifi
* Hostap - AR5416, AR9160, AR9280
* Mesh - some testing by monthadar@, more to come.
This framework allows drivers to abstract the rate control algorithm and
just feed the framework with the usable parameters. The rate control
framework will now deal with passing the parameters to the selected
algorithm. Right now we have AMRR (the default) and RSSADAPT but there's
no way to select one with ifconfig, yet.
The objective is to have more rate control algorithms in the net80211
stack so all drivers[0] can use it. Ideally, we'll have the well-known
sample rate control algorithm in the net80211 at some point so all
drivers can use it (not just ath).
[0] all drivers that do rate control in software, that is.
Reviewed by: bschmidt, thompsa, weyongo
MFC after: 1 months
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
long-term work before they can be serviced. Packets are tagged and
assigned an age (in seconds) at the point they are added to the
queue. If a packet is not retrieved before it's age expires it is
reclaimed. Tagging can take two forms: a reference to an ieee80211_node
(as happens in the tx path) or an opaque token in cases where there
is no reference or the node structure is not stable (i.e. it's going
to be destroyed).
o add ic_stageq to replace the per-node wds staging queue used for
dynamic wds
o add ieee80211_mac_hash for building ageq tokens; this computes a
32-bit hash from an 802.11 mac address (copied from the bridge)
o while here fix a stray ';' noticed in IEEE80211_PSQ_INIT
Reviewed by: rpaulo
Approved by: re (kensmith)
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
used for s/w retransmit schemes that want to access this information
w/o the overhead of decoding the raw frame. Note this also allows
drivers to record this information w/o writing the frame when the seq#
is obtained through an out-of-band mechanism (e.g. when a h/w assigned
seq# is reported in a descriptor on tx done notification).
Reviewed by: sephe, avatar
to be encapsulated before dispatching to the driver
o eliminate M_WDS now that we call ieee80211_encap directly and can supply
the wds vap to indicate a 4-address frame should be created
When copying big structures, LLVM generates calls to memmove(), because
it may not be able to figure out whether structures overlap. This caused
linker errors to occur. memmove() is now implemented using bcopy().
Ideally it would be the other way around, but that can be solved in the
future. On ARM we don't do add anything, because it already has
memmove().
Discussed on: arch@
Reviewed by: rdivacky
the net80211 layer has complete control over the handling of mgt frames
(in particular, the ac, tx rate, and retry count); this also allows us
to purge the M_LINK0 flag that was attached to mbufs to mark them as
needing encryption for shared key auth
o change ieee80211_send_setup to take a tid parameter so it can be used
to setup QoS frames
For receive:
o explicitly tag rx frames w/ M_AMPDU instead of passing frames through
the reorder processing according to the node having HT and the frame
being QoS data
o relax ieee80211_ampdu_reorder asserts to allow any frame to be passed
in, unsuitable frames are returned to the caller for normal processing;
this permits drivers that cannot inspect the PLCP to mark all data
frames as potential ampdu candidates with only a small penalty
o add M_AMPDU_MPDU to identify frames resubmitted from the reorder q
For transmit:
o tag aggregation candidates with M_AMPDU_MPDU
o fix the QoS ack policy set in ampdu subframes; we only support immediate
BA streams which should be marked for "normal ack" to get implicit block
ack behaviour; interestingly certain vendor parts BA'd frames with the
11e BA ack policy set
o do not assign a sequence # to aggregation candidates; this must be done
when frames are submitted for transmit (NB: this can/will be handled
better when aggregation is pulled up to net80211)
o construct a name for the com lock as done for other locks
o pass the device name to IEEE80211_LOCK_INIT so the mtx name
is constructed as foo_com_lock
o introduce *_LOCK_OBJ macro's to hide the lock contents and
minimize redundant code
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)
device and have had the crypto bits stripped from the 802.11 header
o strip mbuf flags in the rx path before passing up the stack
Reviewed by: thompsa, sephe, avatar
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.
station exiting power save mode prepend them to the driver's
send q instead of appending them. This insures the packets
are not misordered wrt any packets already q'd for the station.
This corrects a problem noticed when using a VoIP phone talking
to an ath card in ap mode; the misordered packets caused noise.
Submitted by: "J.R. Oldroyd" <jr@opal.com>
MFC after: 2 weeks
the state machine clocks to INIT, node references are not reclaimed.
Add a new routine ieee80211_drain_ifq that does this and use it
instead of IF_DRAIN.
Submitted by: Sepherosa Ziehau
Obtained from: DragonFly
MFC after: 1 month
Crypto changes:
o change driver/net80211 key_alloc api to return tx+rx key indices; a
driver can leave the rx key index set to IEEE80211_KEYIX_NONE or set
it to be the same as the tx key index (the former disables use of
the key index in building the keyix->node mapping table and is the
default setup for naive drivers by null_key_alloc)
o add cs_max_keyid to crypto state to specify the max h/w key index a
driver will return; this is used to allocate the key index mapping
table and to bounds check table loookups
o while here introduce ieee80211_keyix (finally) for the type of a h/w
key index
o change crypto notifiers for rx failures to pass the rx key index up
as appropriate (michael failure, replay, etc.)
Node table changes:
o optionally allocate a h/w key index to node mapping table for the
station table using the max key index setting supplied by drivers
(note the scan table does not get a map)
o defer node table allocation to lateattach so the driver has a chance
to set the max key id to size the key index map
o while here also defer the aid bitmap allocation
o add new ieee80211_find_rxnode_withkey api to find a sta/node entry
on frame receive with an optional h/w key index to use in checking
mapping table; also updates the map if it does a hash lookup and the
found node has a rx key index set in the unicast key; note this work
is separated from the old ieee80211_find_rxnode call so drivers do
not need to be aware of the new mechanism
o move some node table manipulation under the node table lock to close
a race on node delete
o add ieee80211_node_delucastkey to do the dirty work of deleting
unicast key state for a node (deletes any key and handles key map
references)
Ath driver:
o nuke private sc_keyixmap mechansim in favor of net80211 support
o update key alloc api
These changes close several race conditions for the ath driver operating
in ap mode. Other drivers should see no change. Station mode operation
for ath no longer uses the key index map but performance tests show no
noticeable change and this will be fixed when the scan table is eliminated
with the new scanning support.
Tested by: Michal Mertl, avatar, others
Reviewed by: avatar, others
MFC after: 2 weeks
don't mark the MORE_DATA bit when taking it off the ps queue, there's
no 802.11 header then; we must wait to do this at encap time so
mark the mbuf instead.
Reviewed by: avatar
Approved by: re (scottl)
Obtained from: Atheros
