Add Unscheduled Automatic Power-Save Delivery (U-APSD) client support. The
idea is that the data frames from the client trigger AP to send the buffered
frames with ACs which have U-APSD enabled. This decreases latency and makes it
possible to save even more power.

Driver needs to use IEEE80211_HW_UAPSD to enable the feature. The current
implementation assumes that firmware takes care of the wakeup and
hardware needing IEEE80211_HW_PS_NULLFUNC_STACK is not yet supported.

Tested with wl1251 on a Nokia N900 and Cisco Aironet 1231G AP and running
various test traffic with ping.
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Kalle and Lennert reported problems with the new work
code, and at least Kalle's problem I was able to trace
to a missing jiffies initialisation.

I also ran into a problem where occasionally I couldn't
connect, which seems fixed with kicking the work items
after scanning.

Finally, also add some sanity checking code to verify
that we're not adding work items while an interface is
down -- that case could lead to something similar to
what Lennert was seeing.

There still seems to be a race condition that we're
trying to figure out separately.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Tested-by: NLennert Buytenhek <buytenh@marvell.com>
Tested-by: NKalle Valo <kalle.valo@iki.fi>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

On a 32 bit system (in this case an omap 3430 system) gcc warned about
pointer conversion:

net/mac80211/work.c: In function 'ieee80211_remain_on_channel_timeout':
net/mac80211/work.c:534: warning: cast from pointer to integer of different size
net/mac80211/work.c: In function 'ieee80211_remain_done':
net/mac80211/work.c:1030: warning: cast from pointer to integer of different size
net/mac80211/work.c: In function 'ieee80211_wk_remain_on_channel':
net/mac80211/work.c:1056: warning: cast from pointer to integer of different size
net/mac80211/work.c: In function 'ieee80211_wk_cancel_remain_on_channel':
net/mac80211/work.c:1072: warning: cast from pointer to integer of different size

Fix it by casting the pointers to unsigned long instead. This makes the
compiler happy again.

Compile-tested only.

Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There's no need to be requeueing the work struct
since we check for the scan after removing items
due to possible timeouts.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This changes mac80211 to allow being off-channel for
any type of work, not just the 'remain-on-channel'
work. This also helps fast transition to a BSS on a
different channel.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This implements the new remain-on-channel cfg80211
command in mac80211, extending the work interface.

Also change the work purge code to be able to clean
up events properly (pretending they timed out.)
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

cfg80211 offers private data for each BSS struct,
which mac80211 uses. However, mac80211 uses internal
and external (cfg80211) BSS pointers interchangeably
and has a hack to put the cfg80211 bss struct into
the private struct.

Remove this hack, properly converting between the
pointers wherever necessary.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently, we insert all user-specified IEs before the HT
IE for association, and after the HT IE for probe requests.
For association, that's correct only if the user-specified
IEs are RSN only, incorrect in all other cases including
WPA. Change this to split apart the user-specified IEs in
two places for association: before the HT IE (e.g. RSN),
after the HT IE (generally empty right now I think?) and
after WMM (all other vendor-specific IEs). For probes,
split the IEs in different places to be correct according
to the spec.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Refactor the code to reserve an skb of the right size
(instead of hoping 200 bytes are enough forever), and
also put HT IE generation into an own function.

Additionally, put the HT IE before the vendor-specific
WMM IE. This still leaves things not quite ordered
correctly, due to user-specified IEs, add a note about
that for now.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The station we're authenticating/associating with
may not always be an AP in the sense that word is
mostly understood, so print only the MAC address
of the peer instead.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In order to use auth/assoc for different purposes
other than MLME, it needs to be split up. For other
purposes, a generic work handling (potentially on
another channel) will be useful.

To achieve that, this patch moves much of the MLME
work handling out of mlme into a new work API. The
API can currently handle probing a specific AP,
authentication and association. The MLME previously
handled probe/authentication as one step and will
continue to do so, but they are separate in the new
work handling.

Work items are RCU-managed to be able to check for
existence of an item for a specific frame in the RX
path, but they can be re-used which the MLME right
now will do for its combined probe/auth step.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>