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>

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>

Calling kobject_uevent_env() can fail mainly due to out of
memory conditions. We do not want to continue during such
conditions so propagate that as well instead of letting
cfg80211 load as if everything is peachy.

Additionally lets clarify that when CRDA is not called during
cfg80211's initialization _and_ if the error is not an -ENOMEM
its because kobject_uevent_env() failed to call CRDA, not because
CRDA failed. For those who want to find out why we also let you
do so by enabling the kernel config CONFIG_CFG80211_REG_DEBUG --
you'll get an actual stack trace.

So for now we'll treat non -ENOMEM kobject_uevent_env() failures as
non fatal during cfg80211's initialization.

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

This makes the core hint path more readable and allows for us to
later make it obvious under what circumstances we need locking or not.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

cfg80211_drv_mutex is protecting more than the driver list,
this renames it and documents what its currently supposed to
protect.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This lets userspace request to get the currently set
regulatory domain.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Let users be more compliant if so desired.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This allows drivers to request strict regulatory settings to
be applied to its devices. This is desirable for devices where
proper calibration and compliance can only be gauranteed for
for the device's programmed regulatory domain. Regulatory
domain settings will be ignored until the device's own
regulatory domain is properly configured. If no regulatory
domain is received only the world regulatory domain will be
applied -- if OLD_REG (default to "US") is not enabled. If
OLD_REG behaviour is not acceptable to drivers they must
update their wiphy with a custom reuglatory prior to wiphy
registration.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Drivers may need more information than just who set the last regulatory domain,
as such lets just pass the last regulatory_request receipt. To do this we need
to move out to headers struct regulatory_request, and enum environment_cap. While
at it lets add documentation for enum environment_cap.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This ensures that the initial REGDOM_SET_BY_CORE upon wiphy registration
respects the wiphy->custom_regulatory setting. Without this and if OLD_REG
is disabled (which will be default soon as we remove it) the
wiphy->custom_regulatory is simply ignored.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Drivers without firmware can also have custom regulatory maps
which do not map to a specific ISO / IEC alpha2 country code.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We ignore regulatory hints for the same alpha2 if we already
have processed the same alpha2 on the current regulatory domain.
For a driver regulatory_hint() this means we copy onto its
wiphy->regd the previously procesed regulatory domain from CRDA
without having to call CRDA again.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This prevents user regulatory changes to be considered prior to previous
pending user, core or driver requests which have not be applied.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>