* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
vfs: make no_llseek the default
vfs: don't use BKL in default_llseek
llseek: automatically add .llseek fop
libfs: use generic_file_llseek for simple_attr
mac80211: disallow seeks in minstrel debug code
lirc: make chardev nonseekable
viotape: use noop_llseek
raw: use explicit llseek file operations
ibmasmfs: use generic_file_llseek
spufs: use llseek in all file operations
arm/omap: use generic_file_llseek in iommu_debug
lkdtm: use generic_file_llseek in debugfs
net/wireless: use generic_file_llseek in debugfs
drm: use noop_llseek
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.
The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.
New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time. Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.
The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.
Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.
Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.
===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
// but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}
@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}
@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}
@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}
@ fops0 @
identifier fops;
@@
struct file_operations fops = {
...
};
@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
.llseek = llseek_f,
...
};
@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
.read = read_f,
...
};
@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
.write = write_f,
...
};
@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
.open = open_f,
...
};
// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
... .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};
@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
... .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};
// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
... .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};
// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};
// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};
@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+ .llseek = default_llseek, /* write accesses f_pos */
};
// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////
@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
.write = write_f,
.read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};
@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};
@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};
@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
This reverts commit 5ed3bc7288.
It turns-out that not all drivers are calling ieee80211_tx_status from a
compatible context. Revert this for now and try again later...
Signed-off-by: John W. Linville <linville@tuxdriver.com>
We never delete the addBA response timer, which
is typically fine, but if the station it belongs
to is deleted very quickly after starting the BA
session, before the peer had a chance to reply,
the timer may fire after the station struct has
been freed already. Therefore, we need to delete
the timer in a suitable spot -- best when the
session is being stopped (which will happen even
then) in which case the delete will be a no-op
most of the time.
I've reproduced the scenario and tested the fix.
This fixes the crash reported at
http://mid.gmane.org/4CAB6F96.6090701@candelatech.com
Cc: stable@kernel.org
Reported-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
commit 8c0c709eea
Author: Johannes Berg <johannes@sipsolutions.net>
Date: Wed Nov 25 17:46:15 2009 +0100
mac80211: move cmntr flag out of rx flags
moved the CMTR flag into the skb's status, and
in doing so introduced a use-after-free -- when
the skb has been handed to cooked monitors the
status setting will touch now invalid memory.
Additionally, moving it there has effectively
discarded the optimisation -- since the bit is
only ever set on freed SKBs, and those were a
copy, it could never be checked.
For the current release, fixing this properly
is a bit too involved, so let's just remove the
problematic code and leave userspace with one
copy of each frame for each virtual interface.
Cc: stable@kernel.org [2.6.33+]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The default llseek operation is changing from
default_llseek to no_llseek, so all code relying on
the current behaviour needs to make that explicit.
The wireless driver infrastructure and some of the drivers
make use of generated debugfs files, so they cannot
be converted by our script that automatically determines
the right operation.
All these files use debugfs and they typically rely
on simple_read_from_buffer, so the best llseek operation
here is generic_file_llseek.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (26 commits)
pkt_sched: Fix lockdep warning on est_tree_lock in gen_estimator
ipvs: avoid oops for passive FTP
Revert "sky2: don't do GRO on second port"
gro: fix different skb headrooms
bridge: Clear INET control block of SKBs passed into ip_fragment().
3c59x: Remove incorrect locking; correct documented lock hierarchy
sky2: don't do GRO on second port
ipv4: minor fix about RPF in help of Kconfig
xfrm_user: avoid a warning with some compiler
net/sched/sch_hfsc.c: initialize parent's cl_cfmin properly in init_vf()
pxa168_eth: fix a mdiobus leak
net sched: fix kernel leak in act_police
vhost: stop worker only if created
MAINTAINERS: Add ehea driver as Supported
ath9k_hw: fix parsing of HT40 5 GHz CTLs
ath9k_hw: Fix EEPROM uncompress block reading on AR9003
wireless: register wiphy rfkill w/o holding cfg80211_mutex
netlink: Make NETLINK_USERSOCK work again.
irda: Correctly clean up self->ias_obj on irda_bind() failure.
wireless extensions: fix kernel heap content leak
...
The new workqueue changes helped me find this bug
that's been lingering since the changes to the work
processing in mac80211 -- the work timer is never
deleted properly. Do that to avoid having it fire
after all data structures have been freed. It can't
be re-armed because all it will do, if running, is
schedule the work, but that gets flushed later and
won't have anything to do since all work items are
gone by now (by way of interface removal).
Cc: stable@kernel.org [2.6.34+]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Since the writing to sysfs can free the old one, we need to block that
when we access the charp variables.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Dan Williams <dcbw@redhat.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Jing Huang <huangj@brocade.com>
Cc: James E.J. Bottomley <James.Bottomley@suse.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: libertas-dev@lists.infradead.org
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-usb@vger.kernel.org
The warning is:
net/mac80211/main.c:688: warning: label ‘fail_ifa’ defined but not used
Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Releasing the scan mutex while starting scans
can lead to unexpected things happening, so
we shouldn't do that. Fix that and hold the
mutex across the scan triggering.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Some features require knowing the DTIM period
before associating. This implements the ability
to wait for a beacon in mac80211 before assoc
to provide this value. It is optional since
most likely not all drivers will need this.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
For some drivers it can be useful to know whether the channel they're
supposed to switch to is going to be used for short off-channel work or
scanning, or whether the hardware is expected to stay on it for a while
longer. This is important for various kinds of calibration work, which
takes longer to complete and should keep some persistent state, even if
the channel temporarily changes.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This reverts this commit. While in theory the change is
correct the patch does not address current assumptions made
by some drivers, one which is definitley affected is ath9k.
Prior to this change the scan complete callback would be
called after we returned to the home channel and configured
the hardware RX filters. After this change we call the scan
complete callback prior to both the hw config and the config
filter. At least for ath9k this breaks quite a few assumptions
on the callback, leading to disconnects to the AP after every scan
making the driver pretty useless on STA mode. The goal behind
this commit was to address the now understood spurious warnings
from ath9k and mac80211_hwsim on scanning on two wiphys at the
same time but we have now supressed these and will address this
issue in the next kernel release.
When fixing this for good next we must first review the other
driver's dependence on this logic and perhaps consider removal
of the scan complete callback all together.
Cc: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John 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: Yuri Ershov <ext-yuri.ershov@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Key locking simplification removed key->sdata != NULL verification from
ieee80211_key_free(). While that is fine for most use cases, there is one
path where this function can be called with an unlinked key (i.e.,
key->sdata == NULL && key->local == NULL). This results in a NULL pointer
dereference with the current implementation. This is known to happen at
least with FT protocol when wpa_supplicant tries to configure the key
before association.
Avoid the issue by passing in the local pointer to
ieee80211_key_free(). In addition, do not clear the key from hw_accel
or debugfs if it has not yet been added. At least the hw_accel one could
trigger another NULL pointer dereference.
Signed-off-by: Jouni Malinen <j@w1.fi>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
In AP mode, there is no need to notify the driver about QoS
changes for the monitor interface that is created. The warning
in ieee80211_bss_info_change_notify() would be hit otherwise.
Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John 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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Another remnant of the previous key locking scheme
needs to be removed -- this causes a warning
otherwise as ieee80211_set_default_mgmt_key will
acquire a mutex.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The intent was to free "msp->ratelist" here. "msp->sample_table" is
always NULL at this point.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
"It's not problematic if minstrel gets feedback for rates that it
doesn't have in its list, it should just ignore it. - Felix"
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Cc: Felix Fietkau <nbd@openwrt.org>
If sta is NULL, we will have problems long before we get here...
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Cc: Felix Fietkau <nbd@openwrt.org>
IBSS has never had locking, instead relying on some
memory barriers etc. That's hard to get right, and
I think we had it wrong too until the previous patch.
Since this is not performance sensitive, it doesn't
make sense to have the maintenance overhead of that,
so add proper locking.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Bob reported a lockdep complaint originating in
the mac80211 IBSS code due to the common work
struct patch. The reason is that the IBSS and
station mode code have different locking orders
for the cfg80211 wdev lock and the work struct
(where "locking" implies running/canceling).
Fix this by simply not canceling the work in
the IBSS code, it is not necessary since when
the REQ_RUN bit is cleared, the work will run
without effect if it runs. When the interface
is set down, it is flushed anyway, so there's
no concern about it running after memory has
been invalidated either.
This fixes
https://bugzilla.kernel.org/show_bug.cgi?id=16419
Additionally, looking into this I noticed that
there's a small window while the IBSS is torn
down in which the work may be rescheduled and
the REQ_RUN bit be set again after leave() has
cleared it when a scan finishes at exactly the
same time. Avoid that by setting the ssid_len
to zero before clearing REQ_RUN which signals
to the scan finish code that this interface is
not active.
Reported-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When WEP is not available, we should reject shared
key authentication because it could never succeed.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
If a station interface is reused as monitor interface it is possible that
the carrier is still set to off. This breaks packet injection on that
monitor interface.
Force the carrier on in monitor interface initialisation like it is also done
for other interface types (e.g. adhoc, mesh point, ap).
Signed-off-by: David Gnedt <david.gnedt@davizone.at>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Ever since
commit e1b3ec1a2a
Author: Stanislaw Gruszka <sgruszka@redhat.com>
Date: Mon Mar 29 12:18:34 2010 +0200
mac80211: explicitly disable/enable QoS
mac80211 is telling drivers, in particular
iwlwifi, whether QoS is enabled or not.
However, this is only relevant for station mode,
since only then will any device send nullfunc
frames and need to know whether they should be
QoS frames or not. In other modes, there are
(currently) no frames the device is supposed to
send.
When you now consider virtual interfaces, it
becomes apparent that the current mechanism is
inadequate since it enables/disables QoS on a
global scale, where for nullfunc frames it has
to be on a per-interface scale.
Due to the above considerations, we can change
the way mac80211 advertises the QoS state to
drivers to only ever advertise it as "off" in
station mode, and make it a per-BSS setting.
Tested-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When aggregation related action frames are enqueued for further work,
and they originate from a STA that is part of an AP VLAN, they are
currently enqueued for the AP interface. This breaks the sta_info_get()
lookup in the actual work function, and because of that, aggregation
sessions are not established for this STA.
Fix this by replacing the sta_info_get call with a call to
sta_info_get_bss.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Do this by poisoning the values of wep_tx_tfm and wep_rx_tfm if either
crypto allocation fails.
Reported-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch will also fix the odd freeze which occurred
when minstrel_ht connects to an 802.11n network with
legacy hardware.
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The current mac80211 code assumes that WEP is always available. If WEP
fails to initialize, ieee80211_register_hw will always fail.
In some cases (e.g. FIPS certification), the cryptography used by WEP is
unavailable. However, in such cases there is no good reason why CCMP
encryption (or even no link level encryption) cannot be used. So, this
patch removes mac80211's assumption that WEP (and TKIP) will always be
available for use.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The check should be against current top2 rate, instead of
current top rate.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The throughput should be considered when updating rate
with best probability.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Allow selection of minstrel_ht as default rate control algorithm. At
the moment minstrel_ht can only be requested by the driver code but
not selected as default in make menuconfig. Fix this by using
minstrel_ht when minstrel was selected as default and minstrel_ht
is available.
This change won't affect legacy devices as minstrel_ht falls back to
minstrel in that case.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This check is duplicated in drv_get_survey.
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Because of an ambiguity in the for_each_sta_info macro, it can
currently only be used if the third parameter is set to 'sta'.
Fix this by renaming the parameter to '_sta'.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
