1 files changed, 117 insertions, 11 deletions

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 4f877535e666..bc494cef2102 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -421,6 +421,31 @@ static u32 freq_max_bandwidth(const struct ieee80211_freq_range *freq_range,
         return 0;
 }
 
+/**
+ * freq_in_rule_band - tells us if a frequency is in a frequency band
+ * @freq_range: frequency rule we want to query
+ * @freq_khz: frequency we are inquiring about
+ *
+ * This lets us know if a specific frequency rule is or is not relevant to
+ * a specific frequency's band. Bands are device specific and artificial
+ * definitions (the "2.4 GHz band" and the "5 GHz band"), however it is
+ * safe for now to assume that a frequency rule should not be part of a
+ * frequency's band if the start freq or end freq are off by more than 2 GHz.
+ * This resolution can be lowered and should be considered as we add
+ * regulatory rule support for other "bands".
+ **/
+static bool freq_in_rule_band(const struct ieee80211_freq_range *freq_range,
+        u32 freq_khz)
+{
+#define ONE_GHZ_IN_KHZ  1000000
+        if (abs(freq_khz - freq_range->start_freq_khz) <= (2 * ONE_GHZ_IN_KHZ))
+                return true;
+        if (abs(freq_khz - freq_range->end_freq_khz) <= (2 * ONE_GHZ_IN_KHZ))
+                return true;
+        return false;
+#undef ONE_GHZ_IN_KHZ
+}
+
 /* Converts a country IE to a regulatory domain. A regulatory domain
  * structure has a lot of information which the IE doesn't yet have,
  * so for the other values we use upper max values as we will intersect
@@ -538,6 +563,7 @@ static struct ieee80211_regdomain *country_ie_2_rd(
 
         /* This time around we fill in the rd */
         while (country_ie_len >= 3) {
+                int end_channel = 0;
                 struct ieee80211_country_ie_triplet *triplet =
                         (struct ieee80211_country_ie_triplet *) country_ie;
                 struct ieee80211_reg_rule *reg_rule = NULL;
@@ -559,6 +585,23 @@ static struct ieee80211_regdomain *country_ie_2_rd(
 
                 reg_rule->flags = flags;
 
+                /* 2 GHz */
+                if (triplet->chans.first_channel <= 14)
+                        end_channel = triplet->chans.first_channel +
+                                triplet->chans.num_channels;
+                else
+                        /*
+                         * 5 GHz -- For example in country IEs if the first
+                         * channel given is 36 and the number of channels is 4
+                         * then the individual channel numbers defined for the
+                         * 5 GHz PHY by these parameters are: 36, 40, 44, and 48
+                         * and not 36, 37, 38, 39.
+                         *
+                         * See: http://tinyurl.com/11d-clarification
+                         */
+                        end_channel =  triplet->chans.first_channel +
+                                (4 * (triplet->chans.num_channels - 1));
+
                 /* The +10 is since the regulatory domain expects
                  * the actual band edge, not the center of freq for
                  * its start and end freqs, assuming 20 MHz bandwidth on
@@ -568,8 +611,7 @@ static struct ieee80211_regdomain *country_ie_2_rd(
                                 triplet->chans.first_channel) - 10);
                 freq_range->end_freq_khz =
                         MHZ_TO_KHZ(ieee80211_channel_to_frequency(
-                                triplet->chans.first_channel +
-                                        triplet->chans.num_channels) + 10);
+                                end_channel) + 10);
 
                 /* Large arbitrary values, we intersect later */
                 /* Increment this if we ever support >= 40 MHz channels
@@ -748,12 +790,23 @@ static u32 map_regdom_flags(u32 rd_flags)
  *      this value to the maximum allowed bandwidth.
  * @reg_rule: the regulatory rule which we have for this frequency
  *
- * Use this function to get the regulatory rule for a specific frequency.
+ * Use this function to get the regulatory rule for a specific frequency on
+ * a given wireless device. If the device has a specific regulatory domain
+ * it wants to follow we respect that unless a country IE has been received
+ * and processed already.
+ *
+ * Returns 0 if it was able to find a valid regulatory rule which does
+ * apply to the given center_freq otherwise it returns non-zero. It will
+ * also return -ERANGE if we determine the given center_freq does not even have
+ * a regulatory rule for a frequency range in the center_freq's band. See
+ * freq_in_rule_band() for our current definition of a band -- this is purely
+ * subjective and right now its 802.11 specific.
  */
 static int freq_reg_info(u32 center_freq, u32 *bandwidth,
                          const struct ieee80211_reg_rule **reg_rule)
 {
         int i;
+        bool band_rule_found = false;
         u32 max_bandwidth = 0;
 
         if (!cfg80211_regdomain)
@@ -767,7 +820,15 @@ static int freq_reg_info(u32 center_freq, u32 *bandwidth,
                 rr = &cfg80211_regdomain->reg_rules[i];
                 fr = &rr->freq_range;
                 pr = &rr->power_rule;
+
+                /* We only need to know if one frequency rule was
+                 * was in center_freq's band, that's enough, so lets
+                 * not overwrite it once found */
+                if (!band_rule_found)
+                        band_rule_found = freq_in_rule_band(fr, center_freq);
+
                 max_bandwidth = freq_max_bandwidth(fr, center_freq);
+
                 if (max_bandwidth && *bandwidth <= max_bandwidth) {
                         *reg_rule = rr;
                         *bandwidth = max_bandwidth;
@@ -775,23 +836,64 @@ static int freq_reg_info(u32 center_freq, u32 *bandwidth,
                 }
         }
 
+        if (!band_rule_found)
+                return -ERANGE;
+
         return !max_bandwidth;
 }
 
-static void handle_channel(struct ieee80211_channel *chan)
+static void handle_channel(struct wiphy *wiphy, enum ieee80211_band band,
+                           unsigned int chan_idx)
 {
         int r;
-        u32 flags = chan->orig_flags;
+        u32 flags;
         u32 max_bandwidth = 0;
         const struct ieee80211_reg_rule *reg_rule = NULL;
         const struct ieee80211_power_rule *power_rule = NULL;
+        struct ieee80211_supported_band *sband;
+        struct ieee80211_channel *chan;
+
+        sband = wiphy->bands[band];
+        BUG_ON(chan_idx >= sband->n_channels);
+        chan = &sband->channels[chan_idx];
+
+        flags = chan->orig_flags;
 
         r = freq_reg_info(MHZ_TO_KHZ(chan->center_freq),
                 &max_bandwidth, &reg_rule);
 
         if (r) {
-                flags |= IEEE80211_CHAN_DISABLED;
-                chan->flags = flags;
+                /* This means no regulatory rule was found in the country IE
+                 * with a frequency range on the center_freq's band, since
+                 * IEEE-802.11 allows for a country IE to have a subset of the
+                 * regulatory information provided in a country we ignore
+                 * disabling the channel unless at least one reg rule was
+                 * found on the center_freq's band. For details see this
+                 * clarification:
+                 *
+                 * http://tinyurl.com/11d-clarification
+                 */
+                if (r == -ERANGE &&
+                    last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
+#ifdef CONFIG_CFG80211_REG_DEBUG
+                        printk(KERN_DEBUG "cfg80211: Leaving channel %d MHz "
+                                "intact on %s - no rule found in band on "
+                                "Country IE\n",
+                                chan->center_freq, wiphy_name(wiphy));
+#endif
+                } else {
+                /* In this case we know the country IE has at least one reg rule
+                 * for the band so we respect its band definitions */
+#ifdef CONFIG_CFG80211_REG_DEBUG
+                        if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE)
+                                printk(KERN_DEBUG "cfg80211: Disabling "
+                                        "channel %d MHz on %s due to "
+                                        "Country IE\n",
+                                        chan->center_freq, wiphy_name(wiphy));
+#endif
+                        flags |= IEEE80211_CHAN_DISABLED;
+                        chan->flags = flags;
+                }
                 return;
         }
 
@@ -808,12 +910,16 @@ static void handle_channel(struct ieee80211_channel *chan)
                 chan->max_power = (int) MBM_TO_DBM(power_rule->max_eirp);
 }
 
-static void handle_band(struct ieee80211_supported_band *sband)
+static void handle_band(struct wiphy *wiphy, enum ieee80211_band band)
 {
-        int i;
+        unsigned int i;
+        struct ieee80211_supported_band *sband;
+
+        BUG_ON(!wiphy->bands[band]);
+        sband = wiphy->bands[band];
 
         for (i = 0; i < sband->n_channels; i++)
-                handle_channel(&sband->channels[i]);
+                handle_channel(wiphy, band, i);
 }
 
 static bool ignore_reg_update(struct wiphy *wiphy, enum reg_set_by setby)
@@ -840,7 +946,7 @@ void wiphy_update_regulatory(struct wiphy *wiphy, enum reg_set_by setby)
         enum ieee80211_band band;
         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
                 if (wiphy->bands[band])
-                        handle_band(wiphy->bands[band]);
+                        handle_band(wiphy, band);
                 if (wiphy->reg_notifier)
                         wiphy->reg_notifier(wiphy, setby);
         }