linux/net/wireless/reg.h
Johannes Berg 9caf036402 cfg80211: fix BSS struct IE access races
When a BSS struct is updated, the IEs are currently
overwritten or freed. This can lead to races if some
other CPU is accessing the BSS struct and using the
IEs concurrently.

Fix this by always allocating the IEs in a new struct
that holds the data and length and protecting access
to this new struct with RCU.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-11-30 13:42:20 +01:00

106 lines
4.5 KiB
C

#ifndef __NET_WIRELESS_REG_H
#define __NET_WIRELESS_REG_H
/*
* Copyright 2008-2011 Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
extern const struct ieee80211_regdomain *cfg80211_regdomain;
bool is_world_regdom(const char *alpha2);
bool reg_is_valid_request(const char *alpha2);
bool reg_supported_dfs_region(u8 dfs_region);
int regulatory_hint_user(const char *alpha2,
enum nl80211_user_reg_hint_type user_reg_hint_type);
int reg_device_uevent(struct device *dev, struct kobj_uevent_env *env);
void wiphy_regulatory_register(struct wiphy *wiphy);
void wiphy_regulatory_deregister(struct wiphy *wiphy);
int __init regulatory_init(void);
void regulatory_exit(void);
int set_regdom(const struct ieee80211_regdomain *rd);
bool reg_last_request_cell_base(void);
/**
* regulatory_hint_found_beacon - hints a beacon was found on a channel
* @wiphy: the wireless device where the beacon was found on
* @beacon_chan: the channel on which the beacon was found on
* @gfp: context flags
*
* This informs the wireless core that a beacon from an AP was found on
* the channel provided. This allows the wireless core to make educated
* guesses on regulatory to help with world roaming. This is only used for
* world roaming -- when we do not know our current location. This is
* only useful on channels 12, 13 and 14 on the 2 GHz band as channels
* 1-11 are already enabled by the world regulatory domain; and on
* non-radar 5 GHz channels.
*
* Drivers do not need to call this, cfg80211 will do it for after a scan
* on a newly found BSS. If you cannot make use of this feature you can
* set the wiphy->disable_beacon_hints to true.
*/
int regulatory_hint_found_beacon(struct wiphy *wiphy,
struct ieee80211_channel *beacon_chan,
gfp_t gfp);
/**
* regulatory_hint_11d - hints a country IE as a regulatory domain
* @wiphy: the wireless device giving the hint (used only for reporting
* conflicts)
* @band: the band on which the country IE was received on. This determines
* the band we'll process the country IE channel triplets for.
* @country_ie: pointer to the country IE
* @country_ie_len: length of the country IE
*
* We will intersect the rd with the what CRDA tells us should apply
* for the alpha2 this country IE belongs to, this prevents APs from
* sending us incorrect or outdated information against a country.
*
* The AP is expected to provide Country IE channel triplets for the
* band it is on. It is technically possible for APs to send channel
* country IE triplets even for channels outside of the band they are
* in but for that they would have to use the regulatory extension
* in combination with a triplet but this behaviour is currently
* not observed. For this reason if a triplet is seen with channel
* information for a band the BSS is not present in it will be ignored.
*/
void regulatory_hint_11d(struct wiphy *wiphy,
enum ieee80211_band band,
const u8 *country_ie,
u8 country_ie_len);
/**
* regulatory_hint_disconnect - informs all devices have been disconneted
*
* Regulotory rules can be enhanced further upon scanning and upon
* connection to an AP. These rules become stale if we disconnect
* and go to another country, whether or not we suspend and resume.
* If we suspend, go to another country and resume we'll automatically
* get disconnected shortly after resuming and things will be reset as well.
* This routine is a helper to restore regulatory settings to how they were
* prior to our first connect attempt. This includes ignoring country IE and
* beacon regulatory hints. The ieee80211_regdom module parameter will always
* be respected but if a user had set the regulatory domain that will take
* precedence.
*
* Must be called from process context.
*/
void regulatory_hint_disconnect(void);
#endif /* __NET_WIRELESS_REG_H */