The length of the fixed portion of plink confirm frames is 4 bytes longer than
the other plink_action frames. This path corrects an error in the length
adjustment done for these type of frames.
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
If a PREQ frame is received giving us a fresher DSN than what we have, record
the new dsn and mark it as valid. This patch fixes a bug in the setting of the
MESH_PATH_DSN_VALID flag.
Also, minor fix to coding style on that file.
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Mesh frames that could not be immediately resolved were queued with a NULL
info->control.vif. This patch moves the call to mesh_nexthop_lookup closer to
the point where it is handed over to ieee80211_tx(). This ensures that the
unresolved frames are ready to be sent once the path is resolved.
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This prevents calling rcu_synchronize from within the tx path by moving the
table growth code to the mesh workqueue.
Move mesh_table_free and mesh_table_grow from mesh.c to mesh_pathtbl.c and
declare them static.
Also, re-enable mesh in Kconfig and update the configuration description.
Signed-off-by: Javier Cardona <javier@cozybit.com>
Tested-by: Andrey Yurovsky <andrey@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The mesh stack was enabling beaconing without specifying an interval. This
patch defines a default beaconing interval of 1s.
Incidentally, this fixes mesh beaconing in mac80211_hwsim devices.
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This change triggers a path discovery as soon as the link quality degrades
below a certain threshold. This results in a faster path recovery time than
by simply relying on the periodic path refresh mechanism to detect broken
links.
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The fail_avg value is used to compute the mesh metric, and was only being set
by the pid rate control module. This fixes the mesh path selection mechanism
for cards that use mistrel for rate control.
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The 11s task group recently changed the frame mesh multicast/broadcast frame
format to use 3-address. This was done to avoid interactions with widely
deployed lazy-WDS access points.
This patch changes the format of group addressed frames, both mesh-originated
and proxied, to use the data format defined in draft D2.08 and forward. The
address fields used for group addressed frames is:
In 802.11 header
ToDS:0 FromDS:1
addr1: DA (broadcast/multicast address)
addr2: TA
addr3: Mesh SA
In address extension header:
addr4: SA (only present if frame was proxied)
Note that this change breaks backward compatibility with earlier mesh stack
versions.
Signed-off-by: Andrey Yurovsky <andrey@cozybit.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
On locally originated traffic, we refresh active paths after a timeout. The
decision to do this was using the wrong sign and therefore the refresh timer
was triggered for every frame.
Signed-off-by: Andrey Yurovsky <andrey@cozybit.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Also, fix typo in comment.
Signed-off-by: Javier Cardona <javier@cozybit.com>
Tested-by: Andrey Yurovsky <andrey@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
It's really easier to read if it's not indented
as much, so invert the condition and rearrange
the code so the smaller chunk is indented instead.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
There's no need to mask the variable with 0xFFF0
since we ever only use it as a u16 and the lowest
four bits can't ever be non-zero. The compiler
cannot infer the latter, and therefore has to emit
code to do the masking.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When encryption is used, the number of bytes
sent to the peer increases by the IV and ICV.
This is accounted if software encryption is
used, but not if the devices does hardware
encryption. To make the numbers comparable,
never account for that overhead.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The memory layout for scan requests was rather wrong,
we put the scan SSIDs before the channels which could
lead to the channel pointers being unaligned in memory.
It turns out that using a pointer to the channel array
isn't necessary anyway since we can embed a zero-length
array into the struct.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
If we have a lot of frames to transmit at once, for
instance with fragmentation, it can be an optimisation
to only tell the DMA engine about them on the last
fragment/frame to avoid banging the IO too much. This
patch allows implementation such an optimisation by
telling the driver when more frames can be expected.
Currently, this is used by mac80211 only on fragmented
frames, but could also be used in the future on other
frames when the queue was full and there are multiple
frames pending.
Note that drivers need to be careful when using this
flag, they need to kick their DMA engines not just
when this flag is clear, but also when the queue gets
full so that progress can be made.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
In order for userspace to be able to figure out whether
it obtained a consistent snapshot of data or not when
using netlink dumps, we need to have a generation number
in each dump message that indicates whether the list has
changed or not -- its value is arbitrary.
This patch adds such a number to all dumps, this needs
some mac80211 involvement to keep track of a generation
number to start with when adding/removing mesh paths or
stations.
The wiphy and netdev lists can be fully handled within
cfg80211, of course, but generation numbers need to be
stored there as well.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
After being disassociated by the AP, mac80211 currently
reports this to cfg80211, and then goes to delete the
association. That's fine, but cfg80211 assumes that it's
still authenticated, however, mac80211 throws away all
state.
This fixes mac80211 to keep track of the authentication
in that case so that cfg80211 can request a deauth or
new association properly.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Mesh is currently disabled on mac80211, its marked
as broken. This patch gets it to compile though,
to account for the mac80211 workqueue changes.
There was a simple typo in the patches for mesh
for the workqueue migration, but we never compile
tested it as we couldn't even select mesh as its
broken. Lets at least let it compile for those
interested in getting it fixed.
Reported-by: Pat Erley <pat-lkml@erley.org>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
We splice skbs from the pending queue for a TID
onto the local pending queue when tearing down a
block ack request. This is not necessary unless we
actually have received a request to start a block ack
request (rate control, for example). If we never received
that request we should not be splicing the tid pending
queue as it would be null, causing a panic.
Not sure yet how exactly we allowed through a call when the
tid state does not have at least HT_ADDBA_REQUESTED_MSK set,
that will require some further review as it is not quite
obvious.
For more information see the bug report:
http://bugzilla.kernel.org/show_bug.cgi?id=13922
This fixes this oops:
BUG: unable to handle kernel NULL pointer dereference at 00000030
IP: [<f8806c70>] ieee80211_agg_splice_packets+0x40/0xc0 [mac80211]
*pdpt = 0000000002d1e001 *pde = 0000000000000000
Thread overran stack, or stack corrupted
Oops: 0000 [#1] SMP
last sysfs file: /sys/module/aes_generic/initstate
Modules linked in: <bleh>
Pid: 0, comm: swapper Not tainted (2.6.31-rc5-wl #2) Dell DV051
EIP: 0060:[<f8806c70>] EFLAGS: 00010292 CPU: 0
EIP is at ieee80211_agg_splice_packets+0x40/0xc0 [mac80211]
EAX: 00000030 EBX: 0000004c ECX: 00000003 EDX: 00000000
ESI: c1c98000 EDI: f745a1c0 EBP: c076be58 ESP: c076be38
DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
Process swapper (pid: 0, ti=c076a000 task=c0709160 task.ti=c076a000)
Stack: <bleh2>
Call Trace:
[<f8806edb>] ? ieee80211_stop_tx_ba_cb+0xab/0x150 [mac80211]
[<f8802f1e>] ? ieee80211_tasklet_handler+0xce/0x110 [mac80211]
[<c04862ff>] ? net_rx_action+0xef/0x1d0
[<c0149378>] ? tasklet_action+0x58/0xc0
[<c014a0f2>] ? __do_softirq+0xc2/0x190
[<c018eb48>] ? handle_IRQ_event+0x58/0x140
[<c01205fe>] ? ack_apic_level+0x7e/0x270
[<c014a1fd>] ? do_softirq+0x3d/0x40
[<c014a345>] ? irq_exit+0x65/0x90
[<c010a6af>] ? do_IRQ+0x4f/0xc0
[<c014a35d>] ? irq_exit+0x7d/0x90
[<c011d547>] ? smp_apic_timer_interrupt+0x57/0x90
[<c01094a9>] ? common_interrupt+0x29/0x30
[<c010fd9e>] ? mwait_idle+0xbe/0x100
[<c0107e42>] ? cpu_idle+0x52/0x90
[<c054b1a5>] ? rest_init+0x55/0x60
[<c077492d>] ? start_kernel+0x315/0x37d
[<c07743ce>] ? unknown_bootoption+0x0/0x1f9
[<c0774099>] ? i386_start_kernel+0x79/0x81
Code: <bleh3>
EIP: [<f8806c70>] ieee80211_agg_splice_packets+0x40/0xc0 [mac80211] SS:ESP 0068:c076be38
CR2: 0000000000000030
Cc: stable@kernel.org
Testedy-by: Jack Lau <jackelectronics@hotmail.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When an interface is configured in the AP mode, the mac80211
implementation doesn't inform the driver to receive PS Poll frames.
It leads to inability to communicate with power-saving stations
reliably.
The FIF_CONTROL flag isn't passed by mac80211 to
ieee80211_ops.configure_filter when an interface is in the AP mode.
And it's ok, because we don't want to receive ACK frames and other
control ones, but only PS Poll ones.
This patch introduces the FIF_PSPOLL filter flag in addition to
FIF_CONTROL, which means for the driver "pass PS Poll frames".
This flag is passed to the driver:
A) When an interface is configured in the AP mode.
B) In all cases, when the FIF_CONTROL flag was passed earlier (in
addition to it).
Signed-off-by: Igor Perminov <igor.perminov@inbox.ru>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Do a probe request every 30 seconds, and wait for probe response,
half a second This should lower the traffic that card sends, thus save
power Wainting longer for response makes probe more robust against
'slow' access points
Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Retry 5 times (chosen arbitary ), before assuming
that station is out of range.
Fixes frequent disassociations while connected to weak,
and sometimes even strong access points.
Signed-off-by: Maxim Levitky <maximlevitsky@gmail.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Since the bss is always set now once we are connected, if the
bss has its own information element we refer to it and pass that
instead of relying on mac80211's parsing.
Now all cfg80211 drivers get country IE support, automatically and
we reduce the call overhead that we had on mac80211 which called this
upon every beacon and instead now call this only upon a successfull
connection by a STA on cfg80211.
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Some of the recent MLME rework I did broke powersave
because the ps_sdata isn't assigned at the right time,
and the work item wasn't removed from the list before
calling ieee80211_recalc_ps(). To be more specific,
this broke the case where you'd enabled PS before
associating, either automatically or with iwconfig.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The mac80211 workqueue exists to enable mac80211 and drivers
to queue their own work on a single threaded workqueue. mac80211
takes care to flush the workqueue during suspend but we never
really had requirements on drivers for how they should use
the workqueue in consideration for suspend.
We extend mac80211 to document how the mac80211 workqueue should
be used, how it should not be used and finally move raw access to
the workqueue to mac80211 only. Drivers and mac80211 use helpers
to queue work onto the mac80211 workqueue:
* ieee80211_queue_work()
* ieee80211_queue_delayed_work()
These helpers will now warn if mac80211 already completed its
suspend cycle and someone is trying to queue work. mac80211
flushes the mac80211 workqueue prior to suspend a few times,
but we haven't taken the care to ensure drivers won't add more
work after suspend. To help with this we add a warning when
someone tries to add work and mac80211 already completed the
suspend cycle.
Drivers should ensure they cancel any work or delayed work
in the mac80211 stop() callback.
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
sparse complains about a shadowed variable, which
we can just rename, and lots of stuff if the API
tracer is enabled, so kick out the tracer code in
a sparse run -- the macros just confuse it.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When downing interfaces, it's a good idea to tell the driver to
stop sending beacons; that way the driver doesn't need special
code in ops->remove_interface() when it should already handle the
case in bss_info_changed().
This fixes a potential crash with at least ath5k since the vif
pointer will be nullified while beacon interrupts are still active.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Finally! This is what you've all been waiting for!
This patch makes cfg80211 take care of wext emulation
_completely_ by itself, drivers that don't need things
cfg80211 doesn't do yet don't even need to be aware of
wireless extensions.
This means we can also clean up mac80211's and iwm's
Kconfig and make it possible to build them w/o wext
now!
RIP wext.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Since we now have handlers IWESSID for all modes, we can
combine them into one.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Since we now have IWAP handlers for all modes, we can
combine them into one.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Until now we implemented iwfreq for managed mode, we
needed to keep the implementations separate, but now
that we have all versions implemented we can combine
them and export just one handler.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When enqueuing packets on the internal packet queue, we
need to ensure that we have a valid vif pointer since
that is required since the net namespace work. Add some
assertions to verify this, but also don't crash is for
some reason we don't end up with a vif pointer -- warn
and drop the packet in all these cases.
Since this code touches a number of hotpaths, it is
intended to be temporary, or maybe configurable in the
future, at least the bit that is in the path that gets
hit for every packet, ieee80211_tx_pending().
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Fix an oops in ieee80211_scan_state_set_channel which was triggered
if the last scanned channel was skipped (for example due to regulatory
restrictions) by returning to the decision state after each skipped
channel.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Marcel reported a warning, which quite obviously comes
from an oversight in the code handling deauth frames,
and which resulted in multiple follow-up warnings due
to this missing handling. This patch adds the missing
deauth handling (telling cfg80211 about it) and also
removes the follow-up warnings since they could happen
due to races even if nothing is wrong. I've explained
the races in the comments.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Reported-by: Marcel Holtmann <marcel@holtmann.org>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Jan reported that his b43-based laptop hangs during suspend.
The problem turned out to be mac80211 asking the driver to
stop the hardware before removing interfaces, and interface
removal caused b43 to touch the hardware (while down, which
causes the hang).
This patch fixes mac80211 to do reorder these operations to
have them in the correct order -- first remove interfaces
and then stop the hardware. Some more code is necessary to
be able to do so in a race-free manner, in particular it is
necessary to not process frames received during quiescing.
Fixes http://bugzilla.kernel.org/show_bug.cgi?id=13337.
Reported-by: Jan Scholz <scholz@fias.uni-frankfurt.de>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This was caused by patch:
"mac80211: cooperate more with network namespaces"
The version of the patch applied doesn't match Johannes' latest:
http://johannes.sipsolutions.net/patches/kernel/all/LATEST/NNN-mac80211-netns.patch
The skb->cb virtual interface data wasn't being reset for
reuse so ath9k pooped out when trying to dereference the
private rate control info from the skb.
BUG: unable to handle kernel NULL pointer dereference
RIP: 0010:[<ffffffffa0258173>] ath_tx_rc_status+0x33/0x150 [ath9k]
<-- snip etc -->
Reported-by: Davide Pesavento <davidepesa@gmail.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When a station queries us for a PS-poll response, we wrongly
queue the frame on the virtual interface's queue rather than
the pending queue.
Additionally, fix a race condition where we could potentially
send multiple frames to the sleeping station due to using a
station flag rather than a packet flag. When converting to a
packet flag, we can also convert p54 and remove the filter
clearing we added for it.
(Also remove a now dead function)
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Reported-by: Bob Copeland <me@bobcopeland.com>
Tested-by: Bob Copeland <me@bobcopeland.com>
Cc: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
We were issuing probe requests to the associated AP on the wrong
band by having our beacon timer loss trigger while we are scanning.
When we would scan the timer could hit and force us to send a
probe request to the AP but with a chance we'd be on the wrong band.
This leads to finding no usable bitrate but we should not get so
far on the xmit path. We should not be trying to send these probe
request frames so prevent ieee80211_mgd_probe_ap() from sending
these.
As it turns out all callers of ieee80211_mgd_probe_ap() need this
check so we just move the scan check there. This means we can remove
the recenlty added check during ieee80211_sta_monitor_work().
Additionally we now fix a race condition added by the patch
"mac80211: do not monitor the connection while scanning" which
had the same check in ieee80211_sta_conn_mon_timer(). The race
happens because the timer routine *does* a valid check for
scanning but after it queues work into the mac80211 workqueue
the work callback can kick off with scanning enabled and cause
the same issue we were trying to avoid.
The more appropriate solution would be to disable the respective
timers during scan and re-enable them after scan but requires more
complex code and testing.
Cc: Christian Lamparter <chunkeey@web.de>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Reported-by: Fabio Rossi <rossi.f@inwind.it>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When a new MLME work is created, its timeout is initialised
to 0. This is wrong, it could then be thought of as having
an actual timeout in the future (time_is_after_jiffies() can
return true). Instead, it should be initialised to jiffies
so that it will run right away as soon as the mlme work is
executed.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Reported-by: Luciano Roth Coelho <luciano.coelho@nokia.com>
Reported-by: Alban Browaeys <prahal@yahoo.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Rename scan_state to next_scan_state to better reflect
what it is used for.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Introduce a new scan flag "SCAN_OFF_CHANNEL" which basically tells us
that we are currently on a different channel for scanning and cannot
RX/TX. "SCAN_SW_SCANNING" tells us that we are currently running a
software scan but we might as well be on the operating channel to RX/TX.
While "SCAN_SW_SCANNING" is set during the whole scan "SCAN_OFF_CHANNEL"
is set when leaving the operating channel and unset when coming back.
Introduce two new scan states "SCAN_LEAVE_OPER_CHANNEL" and
"SCAN_ENTER_OPER_CHANNEL" which basically implement the functionality we
need to leave the operating channel (send a nullfunc to the AP and stop
the queues) and enter it again (send a nullfunc to the AP and start the
queues again).
Enhance the scan state "SCAN_DECISION" to switch back to the operating
channel after each scanned channel. In the future it sould be simple
to enhance the decision state to scan as much channels in a row as the
qos latency allows us.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Use a bitfield to store the current scan mode instead of two boolean
variables {sw,hw}_scanning. This patch does not introduce functional
changes but allows us to enhance the scan flags later (for example
for background scanning).
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Introduce a new scan state "decision" which is entered after
every completed scan operation and decides about the next steps.
At first the decision is in any case to scan the next channel.
This shouldn't introduce any functional changes.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Instead of queueing the scan work again without delay just process the
next state immediately.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Move the processing of each scan state into its own functions for better
readability. This patch does not introduce functional changes.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This finally opens up the ability to put mac80211 devices
into different network namespaces. As long as you don't
have sysfs, that is.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>