After fixing zd1211rw: use unaligned safe memcmp() in-place of
compare_ether_addr(), I started to see kernel log messages detailing
unaligned access:

  Kernel unaligned access at TPC[100f7f44] sta_info_get+0x24/0x68 [mac80211]

As with the aforementioned patch, the unaligned access was eminating
from a compare_ether_addr() call. Concerned that whilst it was safe to
assume that unalignment was the norm for the zd1211rw, and take
preventative measures, it may not be the case or acceptable to use the
easy fix of changing the call to memcmp().

My research however indicated that it was OK to do this, as there are
a few instances where memcmp() is the preferred mechanism for doing
mac address comparisons throughout the module.
Signed-off-by: NShaddy Baddah <shaddy_baddah@hotmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When debugfs_create_dir fails, sta_info_debugfs_add_work will not
terminate because it will find the same station again and again.
This is possible whenever debugfs fails for whatever reason; one
reason is a race condition in mac80211, unfortunately we cannot
do much about it, so just document it, it just means some station
may be missing from debugfs.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Long awaited, hard work. This patch totally cleans up the rate control
API to remove the requirement to include internal headers outside of
net/mac80211/.

There's one internal use in the PID algorithm left for mesh networking,
we'll have to figure out a way to clean that one up and decide how to
do the peer link evaluation, possibly independent of the rate control
algorithm or via new API.

Additionally, ath9k is left using the cross-inclusion hack for now, we
will add new API where necessary to make this work properly, but right
now I'm not expert enough to do it. It's still off better than before.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch changes mac80211 to share some more data about
stations with drivers. Should help iwlwifi and ath9k when
 they get around to updating, and might also help with
implementing rate control algorithms without internals.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: Sujith Manoharan <Sujith.Manoharan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There's really no reason for mac80211 to be using its
own interface type defines. Use the nl80211 types and
simplify the configuration code a bit: there's no need
to translate them any more now.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

ieee80211_sta_expire uses the internal __sta_info_unlink
function which can become static if this function is moved
to sta_info.c.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently, almost every interface type has a 'bss' pointer
pointing to BSS information. This BSS information, however,
is for a _local_ BSS, not for the BSS we joined, so having
it on a STA mode interface makes little sense, but now they
have it pointing to the master device, which is an AP mode
virtual interface. However, except for some bitrate control
data, this pointer is only used in AP/VLAN modes (for power
saving stations.)

Overall, it is not necessary to even have the master netdev
be a valid virtual interface, and it doesn't have to be on
the list of interfaces either.

This patch changes the master netdev to be special, it now
 - no longer is on the list of virtual interfaces, which
   lets me remove a lot of tests for that
 - no longer has sub_if_data attached, since that isn't used

Additionally, this patch changes some vlan/ap mode handling
that is related to these 'bss' pointers described above (but
in the VLAN case they actually make sense because there they
point to the AP they belong to); it also adds some debugging
code to IEEE80211_DEV_TO_SUB_IF to validate it is not called
on the master netdev any more.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Fix more than 50 kernel-doc warnings in ieee80211/mac80211 kernel-doc notation.
Fix a few typos also.

Note: Some fields are marked as TBD and need to have their description
corrected.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch reworks the mac80211 debug settings making them more focused
and adding help text for those that didn't have one. It also removes a
number of printks that can be triggered remotely and add no value, e.g.
"too short deauthentication frame received - ignoring".

If somebody really needs to debug that they should just add a monitor
interface and look at the frames in wireshark.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

David Ellingsworth posted a bug that was only noticable on UP/NO-PREEMPT
and Michael correctly analysed it to be a spin_lock_bh() section within
a spin_lock_irqsave() section. This adds a separate spinlock for the
sta_info flags to fix that issue and avoid having to take much care
about where the sta flag manipulation functions are called.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Reported-By: NDavid Ellingsworth <david@identd.dyndns.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch updates mac80211 and drivers to be multi-queue aware and
use that instead of the internal queue mapping. Also does a number
of cleanups in various pieces of the code that fall out and reduces
internal mac80211 state size.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch converts mac80211 and all drivers to have transmit
information and status in skb->cb rather than allocating extra
memory for it and copying all the data around. To make it fit,
a union is used where only data that is necessary for all steps
is kept outside of the union.

A number of fixes were done by Ivo, as well as the rt2x00 part
of this patch.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

As discussed earlier, we can unify locking in struct sta_info
and use just a single spinlock protecting all members of the
structure that need protection. Many don't, but one of the
especially bad ones is the 'flags' member that can currently
be clobbered when RX and TX is being processed on different
CPUs at the same time.

Because having four spinlocks for different, mostly exclusive
parts of a single structure is overkill, this patch also kills
the ampdu and mesh plink spinlocks and uses just a single one
for everything. Because none of the spinlocks are nested, this
is safe.

It remains to be seen whether or not we should make the sta
flags use atomic bit operations instead, for now though this
is a safe thing and using atomic operations instead will be
very simple using the new static inline functions this patch
introduces for accessing sta->flags.

Since spin_lock_bh() is used with this lock, there shouldn't
be any contention even if aggregation is enabled at around the
same time as both requires frame transmission/reception which
is in a bh context.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: Tomas Winkler <tomasw@gmail.com>
Cc: Ron Rindjunsky <ron.rindjunsky@intel.com>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This
 * makes the queue number passed to drivers a u16
   (as it will be with skb_get_queue_mapping)
 * removes the useless queue number defines
 * splits hw->queues into hw->queues/ampdu_queues
 * removes the debugfs files for per-queue counters
 * removes some dead QoS code
 * removes the beacon queue configuration for IBSS
   so that the drivers now never get a queue number
   bigger than (hw->queues + hw->ampdu_queues - 1)
   for tx and only in the range 0..hw->queues-1 for
   conf_tx.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch renames all mac80211 files (except ieee80211_i.h) to get rid
of the useless ieee80211_ prefix.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Up to now, key manipulation is supposed to run under RTNL to
avoid concurrent manipulations and also allow the set_key()
hardware callback to sleep. This is not feasible because STA
structs are rcu-protected and thus a lot of operations there
cannot take the RTNL. Also, key references are rcu-protected
so we cannot do things atomically.

This patch changes key locking completely:
 * key operations are now atomic
 * hardware crypto offload is enabled and disabled from
   a workqueue, due to that key freeing is also delayed
 * debugfs code is also run from a workqueue
 * keys reference STAs (and vice versa!) so during STA
   unlink the STAs key reference is removed but not the
   keys STA reference, to avoid races key todo work is
   run before STA destruction.
 * fewer STA operations now need the RTNL which was
   required due to key operations

This fixes the locking problems lockdep pointed out and also
makes things more light-weight because the rtnl isn't required
as much.

Note that the key todo lock/key mutex are global locks, this
is not required, of course, they could be per-hardware instead.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When a STA is supposed to be unlinked but is pinned, it still needs
to be unlinked from all structures. Only at the end of the unlink
process should we check for pin status and invalidate the callers
reference if it is pinned. Move the pin status check down.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

These two symbols are used only in ifdeffed function. Move them to that
section too.
net/mac80211/sta_info.c:387: warning: `__sta_info_pin' defined but not used
net/mac80211/sta_info.c:397: warning: `__sta_info_unpin' defined but not used
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Cc: Michael Wu <flamingice@sourmilk.net>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jiri Benc <jbenc@suse.cz>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Because we queue the sta-debugfs-adding work on our mac80211
workqueue (which needs to be flushed under RTNL) and that work
needs the RTNL, it can currently deadlock, thanks to Reinette
Chatre for pointing out the lockdep warning about this.

This patch fixes it by moving this work to the common kernel
workqueue (using schedule_work) and canceling it as appropriate.

It also fixes a related problem: When a STA is pinned by the
debugfs adding work and sta_info_flush() runs concurrently
it is not guaranteed that all STAs are removed from the driver
before the corresponding interface is removed which may lead
to bugs.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When the IBSS code tries to flush the STA list, it does so in
an atomic context. Flushing isn't safe there, however, and
requires the RTNL, so we need to defer it to a workqueue.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Calling sta_info_destroy() doesn't require RCU-synchronisation
before-hand because it does that internally. However, it does
require rtnl-locking so insert that where necessary.

Also clean up the code doing it internally to be a bit clearer and
not synchronize twice if keys are configured.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When STA structure insertion fails, it has been allocated but isn't
really alive yet, it isn't reachable by any other code and also can't
yet have much configured. This patch changes the code so that when
the insertion fails, the resulting STA pointer is no longer valid
because it is freed.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

sta_info_destroy(NULL) should be valid, but currently isn't because
the argument is dereferenced before the NULL check. There are no
users that currently pass in NULL, i.e. all check before calling the
function, but I want to change that.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch alters the A-MPDU MLME in sta_info to use dynamic allocation,
thus drastically improving memory usage - from a constant ~2 Kbyte in
the previous (static) allocation to a lower limit of ~200 Byte and an upper
limit of ~2 Kbyte.
Signed-off-by: NRon Rindjunsky <ron.rindjunsky@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Skip properly entries whose dev does not match.
Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

I noticed a bug I introduced when mesh is enabled: sta_info_destroy()
will end up calling cancel_timer() on a timer that has never been
initialized because the timer is only initialized in mesh_plink_alloc(),
not in sta_info_alloc(). This patch moves the initialization of all mesh
related fields into sta_info_alloc(), adds a bit of sanity checking to
the cfg80211 handlers and sta_info_insert() and makes mesh_plink_alloc()
a static helper function that is only used from the mesh plink code.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Quite a while ago I started this book. The required kernel-doc
patches have since gone into the tree so it is now possible to
build the book in mainline.

The actual documentation is still rather incomplete and not all
things are linked into the book, but this enables us to edit
the documentation collaboratively, hopefully driver authors can
add documentation based on their experience with mac80211.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When we take down an interface, we need to remove the STA info
items that belong to it because otherwise we might invoke a
sta_notify() callback in the driver when we later delete the
STA entries, but in that case the driver will already have
removed its knowledge of the interface they belonged to leading
to confusion. Also, we could invoke the set_tim() callback after
the driver removed its knowledge of the interface, which can
lead to a crash if it requests a beacon with a then-invalid vif
pointer!

A side effect of this patch is that, because it was easier, it
disallows changing the WDS peer while an interface is up. Should
that actually be necessary, it can be added back, but the WDS
peer STA entry may not be added while the interface is UP so for
now I've simplified the WDS peer's STA entry lifetime management.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

sta_info_add() has two functions: allocating a station info
structure and inserting it into the hash table/list. Splitting
these two functions allows allocating with GFP_KERNEL in many
places instead of GFP_ATOMIC which is now required by the RCU
protection. Additionally, in many places RCU protection is now
no longer needed at all because between sta_info_alloc() and
sta_info_insert() the caller owns the structure.

This fixes a few race conditions with setting initial flags
and similar, but not all (see comments in ieee80211_sta.c and
cfg.c). More documentation on the existing races will be in
a follow-up patch.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This makes access to the STA hash table/list use RCU to protect
against freeing of items. However, it's not a true RCU, the
copy step is missing: whenever somebody changes a STA item it
is simply updated. This is an existing race condition that is
now somewhat understandable.

This patch also fixes the race key freeing vs. STA destruction
by making sure that sta_info_destroy() is always called under
RTNL and frees the key.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Various cleanups, reducing the #ifdef mess and other things.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Includes integration in struct sta_info of mesh peer link elements, previously
on their own mesh peer link table.
Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In order to RCU-ify sta_info, we need to be able to allocate
a key without linking it to an sdata/sta structure (because
allocation cannot be done in an rcu critical section). This
patch splits up ieee80211_key_alloc() and updates all users
appropriately.

While at it, this patch fixes a number of race conditions
such as finally making key replacement atomic, unfortunately
at the expense of more complex code.

Note that this patch documents /existing/ bugs with sta info
and key interaction, there is currently a race condition
when a sta info is freed without holding the RTNL. This will
finally be fixed by a followup patch.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When a STA structure is added, it is often checked whether it
already exists before adding it. This, however, isn't done
atomically so there is a race condition that could lead to two
STA structures being added with the same MAC address. This
patch changes sta_info_add() to return an ERR_PTR in case
of failure and adds the failure mode -EEXIST when the STA
already exists.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This consolidates all TIM handling code to avoid re-introducing
errors with the bitmap/set_tim order and to reduce code. While
reading the code I noticed a possible problem so I also added
a comment about that.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The TIM flag that is kept in each station's info is completely
useless, there's no code (aside from the debugfs display code)
checking it, hence it can be removed. While doing that, I noticed
that the TIM handling is broken when buffered frames expire, so
fix that.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Drivers should be allowed to simply get a complete new beacon when
set_tim() is invoked (and set_tim() is required for drivers that
just want a beacon template!), so we need to update our own TIM
bitmap before calling set_tim() so that getting the beacon will
now get an already updated beacon.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch creates new cfg80211 wiphy API for channel and bitrate
registration and converts mac80211 and drivers to the new API. The
old mac80211 API is completely ripped out. All drivers (except ath5k)
are updated to the new API, in many cases I expect that optimisations
can be done.

Along with the regulatory code I've also ripped out the
IEEE80211_HW_DEFAULT_REG_DOMAIN_CONFIGURED flag, I believe it to be
unnecessary if the hardware simply gives us whatever channels it wants
to support and we then enable/disable them as required, which is pretty
much required for travelling.

Additionally, the patch adds proper "basic" rate handling for STA
mode interface, AP mode interface will have to have new API added
to allow userspace to set the basic rate set, currently it'll be
empty... However, the basic rate handling will need to be moved to
the BSS conf stuff.

I do expect there to be bugs in this, especially wrt. transmit
power handling where I'm basically clueless about how it should work.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>