cfg80211: make regulatory_hint_11d() band specific

In practice APs do not send country IE channel triplets for channels
the AP is not operating on and if they were to do so they would have
to use the regulatory extension which we currently do not process.
No AP has been seen in practice that does this though so just drop
those country IEs.

Additionally it has been noted the first series of country IE
channels triplets are specific to the band the AP sends. Propagate
the band on which the country IE was found on reject the country
IE then if the triplets are ever oustide of the band.

Although we now won't process country IE information with multiple
band information we leave the intersection work as is as it is
technically possible for someone to want to eventually process these
type of country IEs with regulatory extensions.

Cc: Jouni Malinen <jouni.malinen@atheros.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/net/wireless/reg.h b/net/wireless/reg.h
index 3362c7c069b2..3018508226ab 100644
--- a/net/wireless/reg.h
+++ b/net/wireless/reg.h
@@ -41,14 +41,25 @@ int regulatory_hint_found_beacon(struct wiphy *wiphy,
  * 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  * sending us incorrect or outdated information against a country.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,
                          u8 *country_ie,
                          u8 country_ie_len);