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.
Smart NICs with firmware (eg wpi, iwn, the new atheros parts, the intel 7260
series, etc) support doing a lot of things in firmware. This includes but
isn't limited to things like scanning, sending probe requests and receiving
probe responses. However, net80211 doesn't know about any of this - it still
drives the whole scan/probe infrastructure itself.
In order to move towards suppoting smart NICs, the receive path needs to
know about the channel/details for each received packet. In at least
the iwn and 7260 firmware (and I believe wpi, but I haven't tried it yet)
it will do the scanning, power-save and off-channel buffering for you -
all you need to do is handle receiving beacons and probe responses on
channels that aren't what you're currently on. However the whole receive
path is peppered with ic->ic_curchan and manual scan/powersave handling.
The beacon parsing code also checks ic->ic_curchan to determine if the
received beacon is on the correct channel or not.[1]
So:
* add freq/ieee values to ieee80211_rx_stats;
* change ieee80211_parse_beacon() to accept the 'current' channel
as an argument;
* modify the iv_input() and iv_recv_mgmt() methods to include the rx_stats;
* add a new method - ieee80211_lookup_channel_rxstats() - that looks up
a channel based on the contents of ieee80211_rx_stats;
* if it exists, use it in the mgmt path to switch the current channel
(which still defaults to ic->ic_curchan) over to something determined
by rx_stats.
This is enough to kick-start scan offload support in the Intel 7260
driver that Rui/I are working on. It also is a good start for scan
offload support for a handful of existing NICs (wpi, iwn, some USB
parts) and it'll very likely dramatically improve stability/performance
there. It's not the whole thing - notably, we don't need to do powersave,
we should not scan all channels, and we should leave probe request sending
to the firmware and not do it ourselves. But, this allows for continued
development on the above features whilst actually having a somewhat
working NIC.
TODO:
* Finish tidying up how the net80211 input path works.
Right now ieee80211_input / ieee80211_input_all act as the top-level
that everything feeds into; it should change so the MIMO input routines
are those and the legacy routines are phased out.
* The band selection should be done by the driver, not by the net80211
layer.
* ieee80211_lookup_channel_rxstats() only determines 11b or 11g channels
for now - this is enough for scanning, but not 100% true in all cases.
If we ever need to handle off-channel scan support for things like
static-40MHz or static-80MHz, or turbo-G, or half/quarter rates,
then we should extend this.
[1] This is a side effect of frequency-hopping and CCK modes - you
can receive beacons when you think you're on a different channel.
In particular, CCK (which is used by the low 11b rates, eg beacons!)
is decodable from adjacent channels - just at a low SNR.
FH is a side effect of having the hardware/firmware do the frequency
hopping - it may pick up beacons transmitted from other FH networks
that are in a different phase of hopping frequencies.
is used.
Although the module _builds_, it fails to load because of a missing symbol from
ieee80211_tdma.c.
Specifics:
* Always build ieee80211_tdma.c in the module;
* only compile in the code if IEEE80211_SUPPORT_TDMA is defined.
The ieee80211_swbmiss() callout is not called with the ic lock held, so it's
quite possible the scheduler will run the callout during a state change.
This patch:
* changes the swbmiss callout to be locked by the ic lock
* enforces the ic lock being held across the beacon vap functions
by grabbing it inside beacon_miss() and beacon_swmiss().
This ensures that the ic lock is held (and thus the VAP state
stays constant) during beacon miss and software miss processing.
Since the callout is removed whilst the ic lock is held, it also
ensures that the ic lock can't be called during a state change
or exhibit any race conditions seen above.
Both Edgar and Joel report that this patch fixes the crash and
doesn't introduce new issues.
Reported by: Edgar Martinez <emartinez@kbcnetworks.com>
Reported by: Joel Dahl <joel@vnode.se>
Reported by: emaste
o add safety belt in vdetach for failed state block allocation
o fix dynamic change to tdma config; ERESTART may not result in
kicking the state machine so we need to explicitly mark the
beacon for update
Sponsored by:
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
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.
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
