This fixes an incorrect assumption (BUG_ON) made in
cfg80211 when handling country IE regulatory requests.
The assumption was that we won't try to call_crda()
twice for the same event and therefore we will not
recieve two replies through nl80211 for the regulatory
request. As it turns out it is true we don't call_crda()
twice for the same event, however, kobject_uevent_env()
*might* send the udev event twice and/or userspace can
simply process the udev event twice. We remove the BUG_ON()
and simply ignore the duplicate request.

For details refer to this thread:

http://marc.info/?l=linux-wireless&m=124149987921337&w=2

Cc: stable@kernel.org
Reported-by: NMaxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Device drivers using wiphy_apply_custom_regulatory() want some
regulatory settings applied to their wiphy, if no bands were
configured on the wiphy then something went wrong.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There is a race on access to last_request and its alpha2
through reg_is_valid_request() and us possibly processing
first another regulatory request on another CPU. We avoid
this improbably race by locking with the cfg80211_mutex as
we should have done in the first place. While at it add
the assert on locking on reg_is_valid_request().

Cc: stable@kernel.org
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This is more consistent with our nl80211 naming convention
for HT40-/+.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We are not correctly listening to the regulatory max bandwidth
settings. To actually make use of it we need to redesign things
a bit. This patch does the work for that. We do this to so we
can obey to regulatory rules accordingly for use of HT40.

We end up dealing with HT40 by having two passes for each channel.

The first check will see if a 20 MHz channel fits into the channel's
center freq on a given frequency range. We check for a 20 MHz
banwidth channel as that is the maximum an individual channel
will use, at least for now. The first pass will go ahead and
check if the regulatory rule for that given center of frequency
allows 40 MHz bandwidths and we use this to determine whether
or not the channel supports HT40 or not. So to support HT40 you'll
need at a regulatory rule that allows you to use 40 MHz channels
but you're channel must also be enabled and support 20 MHz by itself.

The second pass is done after we do the regulatory checks over
an device's supported channel list. On each channel we'll check
if the control channel and the extension both:

 o exist
 o are enabled
 o regulatory allows 40 MHz bandwidth on its frequency range

This work allows allows us to idependently check for HT40- and
HT40+.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Its possible for cfg80211 to have scheduled the work and for
the global workqueue to not have kicked in prior to a cfg80211
driver's regulatory hint or wiphy_apply_custom_regulatory().

Although this is very unlikely its possible and should fix
this race. When this race would happen you are expected to have
hit a null pointer dereference panic.

Cc: stable@kernel.org
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Tested-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Commit 0ad8acaf "cfg80211: fix NULL pointer deference in
reg_device_remove()" added a check that last_request is non-NULL,
rendering the 2nd check superfluous.  While there, rearrange the code a
bit so it's a little more straight forward.
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

During initialization we would not have received any beacons
so skip processing reg beacon hints, also adds a check to
reg_is_world_roaming() for last_request before accessing its
fields.

This should fix this:

BUG: unable to handle kernel NULL pointer dereference at

IP: [<e0171332>] wiphy_update_regulatory+0x20f/0x295

*pdpt = 0000000008bf1001 *pde = 0000000000000000
Oops: 0000 [#1]
last sysfs file: /sys/class/backlight/eeepc/brightness
Modules linked in: ath5k(+) mac80211 led_class cfg80211
go_bit cfbcopyarea cfbimgblt cfbfillrect ipv6
ydev usual_tables(P) snd_hda_codec_realtek snd_hda_intel
nd_hwdep uhci_hcd snd_pcm_oss snd_mixer_oss i2c_i801
e serio_raw i2c_core pcspkr atl2 snd_pcm intel_agp
re agpgart eeepc_laptop snd_page_alloc ac video backlight
rfkill button processor evdev thermal fan ata_generic

Pid: 2909, comm: modprobe Tainted: Pc #112) 701
EIP: 0060:[<e0171332>] EFLAGS: 00010246 CPU: 0
EIP is at wiphy_update_regulatory+0x20f/0x295 [cfg80211]
EAX: 00000000 EBX: c5da0000 ECX: 00000000 EDX: c5da0060
ESI: 0000001a EDI: c5da0060 EBP: df3bdd70 ESP: df3bdd40
 DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
Process modprobe (pid: 2909, ti=df3bc000 task=c5d030000)
Stack:
 df3bdd90 c5da0060 c04277e0 00000001 00000044 c04277e402
 00000002 c5da0000 0000001a c5da0060 df3bdda8 e01706a2 02
 00000282 000080d0 00000068 c5d53500 00000080 0000028240
Call Trace:
 [<e01706a2>] ? wiphy_register+0x122/0x1b7 [cfg80211]
 [<e0328e02>] ? ieee80211_register_hw+0xd8/0x346
 [<e06a7c9f>] ? ath5k_hw_set_bssid_mask+0x71/0x78 [ath5k]
 [<e06b0c52>] ? ath5k_pci_probe+0xa5c/0xd0a [ath5k]
 [<c01a6037>] ? sysfs_find_dirent+0x16/0x27
 [<c01fec95>] ? local_pci_probe+0xe/0x10
 [<c01ff526>] ? pci_device_probe+0x48/0x66
 [<c024c9fd>] ? driver_probe_device+0x7f/0xf2
 [<c024cab3>] ? __driver_attach+0x43/0x5f
 [<c024c0af>] ? bus_for_each_dev+0x39/0x5a
 [<c024c8d0>] ? driver_attach+0x14/0x16
 [<c024ca70>] ? __driver_attach+0x0/0x5f
 [<c024c5b3>] ? bus_add_driver+0xd7/0x1e7
 [<c024ccb9>] ? driver_register+0x7b/0xd7
 [<c01ff827>] ? __pci_register_driver+0x32/0x85
 [<e00a8018>] ? init_ath5k_pci+0x18/0x30 [ath5k]
 [<c0101131>] ? _stext+0x49/0x10b
 [<e00a8000>] ? init_ath5k_pci+0x0/0x30 [ath5k]
 [<c012f452>] ? __blocking_notifier_call_chain+0x40/0x4c
 [<c013a714>] ? sys_init_module+0x87/0x18b
 [<c0102804>] ? sysenter_do_call+0x12/0x22
Code: b8 da 17 e0 83 c0 04 e8 92 f9 ff ff 84 c0 75 2a 8b
85 c0 74 0c 83 c0 04 e8 7c f9 ff ff 84 c0 75 14 a1 bc da
4 03 74 66 8b 4d d4 80 79 08 00 74 5d a1 e0 d2 17 e0 48
EIP: [<e0171332>] wiphy_update_regulatory+0x20f/0x295
SP 0068:df3bdd40
CR2: 0000000000000004
---[ end trace 830f2dd2a95fd1a8 ]---

This issue is hard to reproduce, but it was noticed and discussed on
this thread:

http://marc.info/?t=123938022700005&r=1&w=2

Cc: stable@kernel.org
Reported-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We forgot to lock using the cfg80211_mutex in
wiphy_apply_custom_regulatory(). Without the lock
there is possible race between processing a reply from CRDA
and a driver calling wiphy_apply_custom_regulatory(). During
the processing of the reply from CRDA we free last_request and
wiphy_apply_custom_regulatory() eventually accesses an
element from last_request in the through freq_reg_info_regd().

This is very difficult to reproduce (I haven't), it takes us
3 hours and you need to be banging hard, but the race is obvious
by looking at the code.

This should only affect those who use this caller, which currently
is ath5k, ath9k, and ar9170.

EIP: 0060:[<f8ebec50>] EFLAGS: 00210282 CPU: 1
EIP is at freq_reg_info_regd+0x24/0x121 [cfg80211]
EAX: 00000000 EBX: f7ca0060 ECX: f5183d94 EDX: 0024cde0
ESI: f8f56edc EDI: 00000000 EBP: 00000000 ESP: f5183d44
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process modprobe (pid: 14617, ti=f5182000 task=f3934d10 task.ti=f5182000)
Stack: c0505300 f7ca0ab4 f5183d94 0024cde0 f8f403a6 f8f63160 f7ca0060 00000000
00000000 f8ebedf8 f5183d90 f8f56edc 00000000 00000004 00000f40 f8f56edc
f7ca0060 f7ca1234 00000000 00000000 00000000 f7ca14f0 f7ca0ab4 f7ca1289
Call Trace:
[<f8ebedf8>] wiphy_apply_custom_regulatory+0x8f/0x122 [cfg80211]
[<f8f3f798>] ath_attach+0x707/0x9e6 [ath9k]
[<f8f45e46>] ath_pci_probe+0x18d/0x29a [ath9k]
[<c023c7ba>] pci_device_probe+0xa3/0xe4
[<c02a860b>] really_probe+0xd7/0x1de
[<c02a87e7>] __driver_attach+0x37/0x55
[<c02a7eed>] bus_for_each_dev+0x31/0x57
[<c02a83bd>] driver_attach+0x16/0x18
[<c02a78e6>] bus_add_driver+0xec/0x21b
[<c02a8959>] driver_register+0x85/0xe2
[<c023c9bb>] __pci_register_driver+0x3c/0x69
[<f8e93043>] ath9k_init+0x43/0x68 [ath9k]
[<c010112b>] _stext+0x3b/0x116
[<c014a872>] sys_init_module+0x8a/0x19e
[<c01049ad>] sysenter_do_call+0x12/0x21
[<ffffe430>] 0xffffe430
=======================
Code: 0f 94 c0 c3 31 c0 c3 55 57 56 53 89 c3 83 ec 14 8b 74 24 2c 89 54 24 0c 89 4c 24 08 85 f6 75
06 8b 35 c8 bb ec f8 a1 cc bb ec f8 <8b> 40 04 83 f8 03 74 3a 48 74 37 8b 43 28 85 c0 74 30 89 c6
8b
EIP: [<f8ebec50>] freq_reg_info_regd+0x24/0x121 [cfg80211] SS:ESP 0068:f5183d44

Cc: stable@kernel.org
Reported-by: NNataraj Sadasivam <Nataraj.Sadasivam@Atheros.com>
Reported-by: NVivek Natarajan <Vivek.Natarajan@Atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Trying to separate header files into net/wireless.h and
net/cfg80211.h has been a source of confusion. Remove
net/wireless.h (because there also is the linux/wireless.h)
and subsume everything into net/cfg80211.h -- except the
definitions for regulatory structures which get moved to
a new header net/regulatory.h.

The "new" net/cfg80211.h is now divided into sections.

There are no real changes in this patch but code shuffling
and some very minor documentation fixes.

I have also, to make things reflect reality, put in a
copyright line for Luis to net/regulatory.h since that
is probably exclusively written by him but was formerly
in a file that only had my copyright line.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This informs userspace when a change has occured on a world
roaming wiphy's channel which has lifted some restrictions
due to a regulatory beacon hint.

Because this is now sent to userspace through the regulatory
multicast group we remove the debug prints we used to use as
they are no longer necessary.
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

As part of our documented API we always respect the orig_flag
settings on a channel. We forgot to follow this for the beacon
hints.
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We won't ever get here as regulatory_hint_core() can only fail
on -ENOMEM and in that case we don't initialize cfg80211 but this is
technically correct code.

This is actually good for stable, where we don't check for -ENOMEM
failure on __regulatory_hint()'s failure.

Cc: stable@kernel.org
Reported-by: NQuentin Armitage <Quentin@armitage.org.uk>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We had left in code to allow interested developers to add
support for parsing country IEs when OLD_REG was enabled.
This never happened and since we're going to remove OLD_REG
lets just remove these comments and code for it.

This code path was never being entered so this has no
functional change.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It seems a few users are using this module parameter although its not
recommended. People are finding it useful despite there being utilities
for setting this in userspace. I'm not aware of any distribution using
this though.

Until userspace and distributions catch up with a default userspace
automatic replacement (GeoClue integration would be nirvana) we copy
the ieee80211_regdom module parameter from OLD_REG to the new reg
code to help these users migrate.

Users who are using the non-valid ISO / IEC 3166 alpha "EU" in their
ieee80211_regdom module parameter and migrate to non-OLD_REG enabled
system will world roam.

This also schedules removal of this same ieee80211_regdom module
parameter circa March 2010. Hope is by then nirvana is reached and
users will abandoned the module parameter completely.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The incorrect assumption is the last regulatory request
(last_request) is always a country IE when processing
country IEs. Although this is true 99% of the time the
first time this happens this could not be true.

This fixes an oops in the branch check for the last_request
when accessing drv_last_ie. The access was done under the
assumption the struct won't be null.

Note to stable: to port to 29 replace as follows, only 29 has
country IE code:

s|NL80211_REGDOM_SET_BY_COUNTRY_IE|REGDOM_SET_BY_COUNTRY_IE

Cc: stable@kernel.org
Reported-by: NQuentin Armitage <Quentin@armitage.org.uk>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Although EU is a bogus alpha2 we need to process the send request
as our code depends on last_request being set.

Cc: stable@kernel.org
Reported-by: NQuentin Armitage <Quentin@armitage.org.uk>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This allows us to send to userspace "regulatory" events.
For now we just send an event when we change regulatory domains.
We also notify userspace when devices are using their own custom
world roaming regulatory domains.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We do this so we can later inform userspace who set the
regulatory domain and provide details of the request.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This is not used as we can always just assume the first
regulatory domain set will _always_ be a static regulatory
domain. REGDOM_SET_BY_CORE will be the first request from
cfg80211 for a regdomain and that then populates the first
regulatory request.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This is the lowest value amongst countries which do enable 5 GHz operation.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

freq_diff is unsigned, so test before subtraction
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Since we already have a regulatory request from the workqueue use that
and avoid a new kzalloc()
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We were passing value by value, lets just pass the struct.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When devices are world roaming they cannot beacon or do active scan
on 5 GHz or on channels 12, 13 and 14 on the 2 GHz band. Although
we have a good regulatory API some cards may _always_ world roam, this
is also true when a system does not have CRDA present. Devices doing world
roaming can still passive scan, if they find a beacon from an AP on
one of the world roaming frequencies we make the assumption we can do
the same and we also remove the passive scan requirement.

This adds support for providing beacon regulatory hints based on scans.
This works for devices that do either hardware or software scanning.
If a channel has not yet been marked as having had a beacon present
on it we queue the beacon hint processing into the workqueue.

All wireless devices will benefit from beacon regulatory hints from
any wireless device on a system including new devices connected to
the system at a later time.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The current static world regulatory domain is too restrictive,
we can use some 5 GHz channels world wide so long as they do not
touch frequencies which require DFS. The compromise is we must
also enforce passive scanning and disallow usage of a mode of
operation that beacons: (AP | IBSS | Mesh)
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This enables active scan and beaconing on Channels 1 through 11
on the static world regulatory domain.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This allows drivers that agree on regulatory to share their
regulatory domain.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

All regulatory hints (core, driver, userspace and 11d) are now processed in
a workqueue.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This was never happening but it was still wrong, so correct it.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Truth of the matter this was confusing people so mark it as
unlikely as that is the case now.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We were not protecting last_request there is a small possible race
between an 11d hint and another routine which calls reset_regdomains()
which can prevent a valid country IE from being processed. This is
not critical as it will still be procesed soon after but locking prior
to it is correct.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We do this so later on we can move the pending requests onto a
workqueue. By using the wiphy_idx instead of the wiphy we can
later easily check if the wiphy has disappeared or not.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>