cfg80211: Handle WMM rules in regulatory domain intersection

The support added for regulatory WMM rules did not handle
the case of regulatory domain intersections. Fix it.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Fixes: 230ebaa1 ("cfg80211: read wmm rules from regulatory database")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/reg.c

@@ -1309,6 +1309,16 @@ reg_intersect_dfs_region(const enum nl80211_dfs_regions dfs_region1,
 	return dfs_region1;
 }
 
+static void reg_wmm_rules_intersect(const struct ieee80211_wmm_ac *wmm_ac1,
+				    const struct ieee80211_wmm_ac *wmm_ac2,
+				    struct ieee80211_wmm_ac *intersect)
+{
+	intersect->cw_min = max_t(u16, wmm_ac1->cw_min, wmm_ac2->cw_min);
+	intersect->cw_max = max_t(u16, wmm_ac1->cw_max, wmm_ac2->cw_max);
+	intersect->cot = min_t(u16, wmm_ac1->cot, wmm_ac2->cot);
+	intersect->aifsn = max_t(u8, wmm_ac1->aifsn, wmm_ac2->aifsn);
+}
+
 /*
  * Helper for regdom_intersect(), this does the real
  * mathematical intersection fun
@@ -1323,6 +1333,8 @@ static int reg_rules_intersect(const struct ieee80211_regdomain *rd1,
 	struct ieee80211_freq_range *freq_range;
 	const struct ieee80211_power_rule *power_rule1, *power_rule2;
 	struct ieee80211_power_rule *power_rule;
+	const struct ieee80211_wmm_rule *wmm_rule1, *wmm_rule2;
+	struct ieee80211_wmm_rule *wmm_rule;
 	u32 freq_diff, max_bandwidth1, max_bandwidth2;
 
 	freq_range1 = &rule1->freq_range;
@@ -1333,6 +1345,10 @@ static int reg_rules_intersect(const struct ieee80211_regdomain *rd1,
 	power_rule2 = &rule2->power_rule;
 	power_rule = &intersected_rule->power_rule;
 
+	wmm_rule1 = &rule1->wmm_rule;
+	wmm_rule2 = &rule2->wmm_rule;
+	wmm_rule = &intersected_rule->wmm_rule;
+
 	freq_range->start_freq_khz = max(freq_range1->start_freq_khz,
 					 freq_range2->start_freq_khz);
 	freq_range->end_freq_khz = min(freq_range1->end_freq_khz,
@@ -1376,6 +1392,29 @@ static int reg_rules_intersect(const struct ieee80211_regdomain *rd1,
 	intersected_rule->dfs_cac_ms = max(rule1->dfs_cac_ms,
 					   rule2->dfs_cac_ms);
 
+	if (rule1->has_wmm && rule2->has_wmm) {
+		u8 ac;
+
+		for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
+			reg_wmm_rules_intersect(&wmm_rule1->client[ac],
+						&wmm_rule2->client[ac],
+						&wmm_rule->client[ac]);
+			reg_wmm_rules_intersect(&wmm_rule1->ap[ac],
+						&wmm_rule2->ap[ac],
+						&wmm_rule->ap[ac]);
+		}
+
+		intersected_rule->has_wmm = true;
+	} else if (rule1->has_wmm) {
+		*wmm_rule = *wmm_rule1;
+		intersected_rule->has_wmm = true;
+	} else if (rule2->has_wmm) {
+		*wmm_rule = *wmm_rule2;
+		intersected_rule->has_wmm = true;
+	} else {
+		intersected_rule->has_wmm = false;
+	}
+
 	if (!is_valid_reg_rule(intersected_rule))
 		return -EINVAL;