mac80211 doesn't handle shared skbs correctly at the moment. As a result
a possible resize can trigger a BUG in pskb_expand_head.

[  676.030000] Kernel bug detected[#1]:
[  676.030000] Cpu 0
[  676.030000] $ 0   : 00000000 00000000 819662ff 00000002
[  676.030000] $ 4   : 81966200 00000020 00000000 00000020
[  676.030000] $ 8   : 819662e0 800043c0 00000002 00020000
[  676.030000] $12   : 3b9aca00 00000000 00000000 00470000
[  676.030000] $16   : 80ea2000 00000000 00000000 00000000
[  676.030000] $20   : 818aa200 80ea2018 80ea2000 00000008
[  676.030000] $24   : 00000002 800ace5c
[  676.030000] $28   : 8199a000 8199bd20 81938f88 80f180d4
[  676.030000] Hi    : 0000026e
[  676.030000] Lo    : 0000757e
[  676.030000] epc   : 801245e4 pskb_expand_head+0x44/0x1d8
[  676.030000]     Not tainted
[  676.030000] ra    : 80f180d4 ieee80211_skb_resize+0xb0/0x114 [mac80211]
[  676.030000] Status: 1000a403    KERNEL EXL IE
[  676.030000] Cause : 10800024
[  676.030000] PrId  : 0001964c (MIPS 24Kc)
[  676.030000] Modules linked in: mac80211_hwsim rt2800lib rt2x00soc rt2x00pci rt2x00lib mac80211 crc_itu_t crc_ccitt cfg80211 compat arc4 aes_generic deflate ecb cbc [last unloaded: rt2800pci]
[  676.030000] Process kpktgend_0 (pid: 97, threadinfo=8199a000, task=81879f48, tls=00000000)
[  676.030000] Stack : ffffffff 00000000 00000000 00000014 00000004 80ea2000 00000000 00000000
[  676.030000]         818aa200 80f180d4 ffffffff 0000000a 81879f78 81879f48 81879f48 00000018
[  676.030000]         81966246 80ea2000 818432e0 80f1a420 80203050 81814d98 00000001 81879f48
[  676.030000]         81879f48 00000018 81966246 818432e0 0000001a 8199bdd4 0000001c 80f1b72c
[  676.030000]         80203020 8001292c 80ef4aa2 7f10b55d 801ab5b8 81879f48 00000188 80005c90
[  676.030000]         ...
[  676.030000] Call Trace:
[  676.030000] [<801245e4>] pskb_expand_head+0x44/0x1d8
[  676.030000] [<80f180d4>] ieee80211_skb_resize+0xb0/0x114 [mac80211]
[  676.030000] [<80f1a420>] ieee80211_xmit+0x150/0x22c [mac80211]
[  676.030000] [<80f1b72c>] ieee80211_subif_start_xmit+0x6f4/0x73c [mac80211]
[  676.030000] [<8014361c>] pktgen_thread_worker+0xfac/0x16f8
[  676.030000] [<8002ebe8>] kthread+0x7c/0x88
[  676.030000] [<80008e0c>] kernel_thread_helper+0x10/0x18
[  676.030000]
[  676.030000]
[  676.030000] Code: 24020001  10620005  2502001f <0200000d> 0804917a  00000000  2502001f  00441023  00531021

Fix this by making a local copy of shared skbs prior to mangeling them.
To avoid copying the skb unnecessarily move the skb_copy call below the
checks that don't need write access to the skb.

Also, move the assignment of nh_pos and h_pos below the skb_copy to point
to the correct skb.

It would be possible to avoid another resize of the copied skb by using
skb_copy_expand instead of skb_copy but that would make the patch more
complex. Also, shared skbs are a corner case right now, so the resize
shouldn't matter much.

Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The last_tx_rate field was also updated for non-data frames that are
often sent with a lower rate (for example management frames at 1 Mbps).
This is confusing when the data rate is actually much higher.

Hence, only update the last_tx_rate field with tx rate information
gathered from last data frames.

If the rate control algorithm filled in txrc.reported_rate we don't need
to verify this information.

Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In order for frame injection to work properly for some use cases
(e.g., finding the station entry and keys for encryption), mac80211
needs to find the correct sdata entry. This works when the main vif
is in AP mode, but commit a2c1e3da
broke this particular use case for station main vif. While this type of
injection is quite unusual operation, it has some uses and we should fix
it. Do this by changing the monitor vif sdata selection to allow station
vif to be selected instead of limiting it to just AP vifs. We still need
to skip some iftypes to avoid selecting unsuitable vif for injection.
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The lower driver is notified when the fragmentation threshold changes
and upon a reconfig of the interface.

If the driver supports hardware TX fragmentation, don't fragment
packets in the stack.
Signed-off-by: NArik Nemtsov <arik@wizery.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This adds API to allow adding per-station GTKs,
updates mac80211 to support it, and also allows
drivers to remove a key from hwaccel again when
this may be necessary due to multiple GTKs.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Initialize the rate table for WDS interfaces, and
add cases to allow WDS packets to pass the xmit and receive
tests.
Signed-off-by: NBill Jordan <bjordan@rajant.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

hdr pointer is left dangling after call to ieee80211_skb_resize. This
can cause guards around mesh path selection to fail.
Signed-off-by: NSteve deRosier <steve@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There are subqueue helpers so that we don't
need to get the TX queue and then wake/stop
it, use those helpers.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Some vendor specified mechanisms for 802.1X-style
functionality use a different protocol than EAP
(even if EAP is vendor-extensible). Support this
in mac80211 via the cfg80211 API for it.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJuuso Oikarinen <juuso.oikarinen@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Allow drivers to specify their own set of cipher
suites to advertise vendor-specific ciphers. The
driver is then required to implement hardware
crypto offload for it.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJuuso Oikarinen <juuso.oikarinen@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

mesh_hdr only used when CONFIG_MAC80211_MESH is defined
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Standardize logging messages from
	printk(KERN_<level> "%s: " fmt , wiphy_name(foo), args);
to
	wiphy_<level>(foo, fmt, args);
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently, mac80211 translates the cfg80211
cipher suite selectors into ALG_* values.
That isn't all too useful, and some drivers
benefit from the distinction between WEP40
and WEP104 as well. Therefore, convert it
all to use the cipher suite selectors.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In the function ieee80211_subif_start_xmit the logic related with
meshdrlen is under CONFIG_MAC80211_MESH macro, but in one place it isn't.
This is some update for this
Signed-off-by: NYuri Ershov <ext-yuri.ershov@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

I just had the following:
WARNING: at drivers/net/wireless/iwlwifi/iwl-agn-tx.c:574 iwlagn_tx_skb+0x1576/0x15f0 [iwlagn]()
Call Trace:
 <IRQ>  [<ffffffff8105c5df>] warn_slowpath_common+0x7f/0xc0
 [<ffffffff8105c63a>] warn_slowpath_null+0x1a/0x20
 [<ffffffffa0290b46>] iwlagn_tx_skb+0x1576/0x15f0 [iwlagn]
 [<ffffffffa027076c>] iwl_mac_tx+0x5c/0x260 [iwlagn]
 [<ffffffffa01bdf5b>] __ieee80211_tx+0x10b/0x1a0 [mac80211]
 [<ffffffffa01bfb86>] ieee80211_tx_pending+0x186/0x2d0 [mac80211]
 [<ffffffff81062ea5>] tasklet_action+0x125/0x130
 [<ffffffff810634a6>] __do_softirq+0x106/0x270
 [<ffffffff8100c09c>] call_softirq+0x1c/0x30
iwlagn 0000:02:00.0: Attempting to modify non-existing station 107

Note that 107 == 0x6b which is slab poison.

The reason is that mac80211 passed a freed station
pointer to mac80211, because as it happened iwlwifi
reset itself while mac80211 was disconnecting from
the network.

It turns out that we do take care to look up the
station pointer in ieee80211_tx_pending_skb, but
then don't use it, which obviously is a bug. Fix
this by removing the ieee80211_tx_h_sta handler
and assigning the station pointer directly.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When the driver or rate control requests starting
or stopping an aggregation session, that currently
causes a direct callback into the driver, which
could potentially cause locking problems. Also,
the functions need to be callable from contexts
that cannot sleep, and thus will interfere with
making the ampdu_action callback sleeping.

To address these issues, add a new work item for
each station that will process any start or stop
requests out of line.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently we allocate some memory for each TX
aggregation session and additionally keep a
state bitmap indicating the state it is in.
By using RCU to protect the pointer, moving
the state into the structure and some locking
trickery we can avoid locking when the TX agg
session is fully operational.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Also simplify the flags assignment into a single statement at the
end of ieee80211_beacon_get_tim.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently whenever rts thresold is set, every packet will use RTS
protection no matter its size exceeds the threshold or not. This is
due to a bug in the rts threshold check.
	if (len > tx->local->hw.wiphy->rts_threshold) {
		txrc.rts = rts = true;
	}
Basically it is comparing an int (len) and a u32 (rts_threshold),
and the variable len is assigned as:
	len = min_t(int, tx->skb->len + FCS_LEN,
			 tx->local->hw.wiphy->frag_threshold);
However, when frag_threshold is "-1", len is always "-1", which is
0xffffffff therefore rts is always set to true.

CC: stable@kernel.org
Signed-off-by: NShanyu Zhao <shanyu.zhao@intel.com>
Reviewed-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The sta_cleanup timer is used to periodically expire buffered frames from the
tx buf. The timer is executing periodically, regardless of the need for it.
This is wasting resources.

Fix this simply by not restarting the sta_cleanup timer if the tx buffer was
empty. Restart the timer when there is some more tx-traffic.

Cc: Janne Ylälehto <janne.ylalehto@nokia.com>
Signed-off-by: NJuuso Oikarinen <juuso.oikarinen@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

All other places except one in the TX path, which
has BHs disabled, and it also cannot be locked from
interrupts so disabling IRQs is not necessary.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

BIP (part of IEEE 802.11w) is only supposed to be used with
group-addressed frames. We ended up picking it as a default mechanism
for every management whenever we did not have a STA entry for the
destination (e.g., for Probe Response to a STA that is not
associated). While the extra MMIE in the end of management frames
should not break frames completed in most cases, there is no point in
doing this. Fix key selection to pick the default management key only
if the frame is sent to multicast/broadcast address and the frame is a
robust management frame.
Signed-off-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

"mac80211: fix skb buffering issue" still left a race
between enabling the hardware queues and the virtual
interface queues. In hindsight it's totally obvious
that enabling the netdev queues for a hardware queue
when the hardware queue is enabled is wrong, because
it could well possible that we can fill the hw queue
with packets we already have pending. Thus, we must
only enable the netdev queues once all the pending
packets have been processed and sent off to the device.

In testing, I haven't been able to trigger this race
condition, but it's clearly there, possibly only when
aggregation is being enabled.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We don't need "sdata" any more after:
	d84f3234
	mac80211: remove dev_hold/put calls
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Many drivers would like to sleep during station
addition and removal, and currently have a high
complexity there from not being able to.

This introduces two new callbacks sta_add() and
sta_remove() that drivers can implement instead
of using sta_notify() and that can sleep, and
the new sta_add() callback is also allowed to
fail.

The reason we didn't do this previously is that
the IBSS code wants to insert stations from the
RX path, which is a tasklet, so cannot sleep.
This patch will keep the station allocation in
that path, but moves adding the station to the
driver out of line. Since the addition can now
fail, we can have IBSS peer structs the driver
rejected -- in that case we still talk to the
station but never tell the driver about it in
the control.sta pointer. If there will ever be
a driver that has a low limit on the number of
stations and that cannot talk to any stations
that are not known to it, we need to do come up
with a new strategy of handling larger IBSSs,
maybe quicker expiry or rejecting peers.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Upstream radiotap has adopted the namespace
proposal David Young made and I then took care
of, for which I had adapted the radiotap parser
as a library outside the kernel. This brings
the in-kernel parser up to speed.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When injecting frames, mac80211 currently looks for the first AP
interface that matches the source address of the injected frame.
This breaks when such a frame is directed at a STA that has been moved
to a VLAN. This patch fixes it by using sta_info_get_bss instead of
sta_info_get, which also finds stations belonging to a VLAN interface
of the same BSS as the AP interface.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When an injected frame gets buffered for a powersave STA or filtered
and retransmitted, mac80211 attempts to parse the radiotap header
again, which doesn't work because it's gone at that point.
This patch adds a new flag for checking the availability of a radiotap
header, so that it only attempts to parse it once, reusing the tx info
on the next call to ieee80211_tx().
This fixes severe issues with rekeying in AP mode.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

What a stupid mistake. In

    commit 813d7669
    Author: Johannes Berg <johannes@sipsolutions.net>
    Date:   Sun Jan 17 01:47:58 2010 +0100

        mac80211: move control.hw_key assignment

I inserted code testing the wrong flags field,
which means that the test is almost always true
(it's really testing for the peer's WMM support)
and thus the later parts of the stack assume hw
crypto will be done even if that's not true.

Obviously, that broke software crypto. Maxim
said so specifically, and Jochen probably uses
some cipher that iwl3945 doesn't support in
hardware, which might also explain that Maxim
reports that even hw crypto is broken.

Fix this to test the right flags field.
Reported-by: NMaxim Levitsky <maximlevitsky@gmail.com>
Reported-by: NJochen Friedrich <jochen@scram.de>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Pavel Roskin reported a crash in ieee80211_tx_h_select_key():

http://marc.info/?l=linux-wireless&m=126419655108528&w=2

This is a regression from patch "mac80211: move control.hw_key assignment".
Fix it as suggested by Johannes, adding an else statement to make sure
that tx->key is not accessed when it's null.

Compile-tested only.
Reported-by: NPavel Roskin <proski@gnu.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: NKalle Valo <kalle.valo@iki.fi>
Tested-by: NBob Copeland <me@bobcopeland.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

ieee80211_tx_h_select_key might decide that a frame
need not be encrypted at all, in which case it will
clear tx->key. In that case it may crash if a key
was previously selected, e.g. as the default key.

This is also due to my patch
"mac80211: move control.hw_key assignment".
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In an earlier commit,

    mac80211: disable software retry for now

    Pavel Roskin reported a problem that seems to be due to
    software retry of already transmitted frames. It turns
    out that we've never done that correctly, but due to
    some recent changes it now crashes in the TX code. I've
    added a comment in the patch that explains the problem
    better and also points to possible solutions -- which
    I can't implement right now.

I disabled software retry of failed/filtered frames
because it was broken. With the work of the previous
patches, it now becomes fairly easy to re-enable it
by adding a flag indicating that the frame shouldn't
be modified, but still running it through the transmit
handlers to populate the control information.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When mac80211 asks a driver to encrypt a frame, it
must assign the control.hw_key pointer for it to
know which key to use etc. Currently, mac80211 does
this whenever it would software-encrypt a frame.

Change the logic of this code to assign the hw_key
pointer when selecting the key, and later check it
when deciding whether to encrypt the frame or let
it be encrypted by the hardware. This allows us to
later simply skip the encryption function since it
no longer modifies the TX control.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There's no value in setting a flag that will
never be checked after this point, this seems
to be legacy code -- I think previously the
flag was used to check whether to encrypt the
frame or not. Now, however, the flag need not
be set, and setting it actually interferes if
the frame will be processed again later.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This TX handler is used only for assigning the
station pointer in the control information, so
give it a better name. Also move it before rate
control.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

To make U-APSD client mode effective, we must not wake up from dynamic power
save when transmitting frames. So if dynamic power save is enabled, it needs
check the queue the transmitted packet is in and decide if we need to wake
up or not.

In a perfect world, where all packets would have correct QoS tags, U-APSD
enabled queues should not trigger wakeup from power save. But in the real
world, where very few packets have correct QoS tags, this won't work. For
example, if only voip class has U-APSD enabled and we send a packet in voip
class, but the packets we receive are in best effort class, we would receive
the packets with the legacy power save method. And that would increase
latencies too much from a voip application point of view.

The workaround is to enable U-APSD for all qeueus and still use dynamic ps
wakeup for all other queues except voip. That way we can still save power
with a voip application and not sacrifice latency. Normal traffic (in
background, best effort or video class) would still trigger wakeup from
dynamic power save.
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently dynamic ps check is in ieee80211_xmit(), but it's cleaner
to have a separate tx handler for this. Also this is a prerequisite for
U-APSD client mode which needs to know the queue frame is in.

Also need_dynamic_ps() function is embedded to the tx handler.

No functional changes expect that the code is run in a later phase than
originally.
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If frames are transmitted on 4-addr ap vlan interfaces with no station,
they end up being transmitted unencrypted, even if the ap interface
uses WPA. This patch add some sanity checking to make sure that this
does not happen.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Certain type of hardware, for example wl1251 and wl1271, need a template
for the Probe Request. Create a function ieee80211_probereq_get() which
creates the template and drivers send it to hardware.
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>