cfg80211: add helper fn for single rule channels

As a preparation to handle adjacent rule channels,
factor out handling channels located in a single
regulatory rule.
Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
Link: https://lore.kernel.org/r/20200803144353.305538-1-markus.theil@tu-ilmenau.deSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/reg.c

@@ -1691,57 +1691,18 @@ static uint32_t reg_rule_to_chan_bw_flags(const struct ieee80211_regdomain *regd
 	return bw_flags;
 }
 
-/*
- * Note that right now we assume the desired channel bandwidth
- * is always 20 MHz for each individual channel (HT40 uses 20 MHz
- * per channel, the primary and the extension channel).
- */
-static void handle_channel(struct wiphy *wiphy,
-			   enum nl80211_reg_initiator initiator,
-			   struct ieee80211_channel *chan)
+static void handle_channel_single_rule(struct wiphy *wiphy,
+				       enum nl80211_reg_initiator initiator,
+				       struct ieee80211_channel *chan,
+				       u32 flags,
+				       struct regulatory_request *lr,
+				       struct wiphy *request_wiphy,
+				       const struct ieee80211_reg_rule *reg_rule)
 {
-	u32 flags, bw_flags = 0;
-	const struct ieee80211_reg_rule *reg_rule = NULL;
+	u32 bw_flags = 0;
 	const struct ieee80211_power_rule *power_rule = NULL;
-	struct wiphy *request_wiphy = NULL;
-	struct regulatory_request *lr = get_last_request();
 	const struct ieee80211_regdomain *regd;
 
-	request_wiphy = wiphy_idx_to_wiphy(lr->wiphy_idx);
-
-	flags = chan->orig_flags;
-
-	reg_rule = freq_reg_info(wiphy, ieee80211_channel_to_khz(chan));
-	if (IS_ERR(reg_rule)) {
-		/*
-		 * We will disable all channels that do not match our
-		 * received regulatory rule unless the hint is coming
-		 * from a Country IE and the Country IE had no information
-		 * about a band. The IEEE 802.11 spec allows for an AP
-		 * to send only a subset of the regulatory rules allowed,
-		 * so an AP in the US that only supports 2.4 GHz may only send
-		 * a country IE with information for the 2.4 GHz band
-		 * while 5 GHz is still supported.
-		 */
-		if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
-		    PTR_ERR(reg_rule) == -ERANGE)
-			return;
-
-		if (lr->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
-		    request_wiphy && request_wiphy == wiphy &&
-		    request_wiphy->regulatory_flags & REGULATORY_STRICT_REG) {
-			pr_debug("Disabling freq %d.%03d MHz for good\n",
-				 chan->center_freq, chan->freq_offset);
-			chan->orig_flags |= IEEE80211_CHAN_DISABLED;
-			chan->flags = chan->orig_flags;
-		} else {
-			pr_debug("Disabling freq %d.%03d MHz\n",
-				 chan->center_freq, chan->freq_offset);
-			chan->flags |= IEEE80211_CHAN_DISABLED;
-		}
-		return;
-	}
-
 	regd = reg_get_regdomain(wiphy);
 
 	power_rule = &reg_rule->power_rule;
@@ -1803,6 +1764,57 @@ static void handle_channel(struct wiphy *wiphy,
 		chan->max_power = chan->max_reg_power;
 }
 
+/* Note that right now we assume the desired channel bandwidth
+ * is always 20 MHz for each individual channel (HT40 uses 20 MHz
+ * per channel, the primary and the extension channel).
+ */
+static void handle_channel(struct wiphy *wiphy,
+			   enum nl80211_reg_initiator initiator,
+			   struct ieee80211_channel *chan)
+{
+	u32 flags = 0;
+	const struct ieee80211_reg_rule *reg_rule = NULL;
+	struct wiphy *request_wiphy = NULL;
+	struct regulatory_request *lr = get_last_request();
+
+	request_wiphy = wiphy_idx_to_wiphy(lr->wiphy_idx);
+
+	flags = chan->orig_flags;
+
+	reg_rule = freq_reg_info(wiphy, ieee80211_channel_to_khz(chan));
+	if (IS_ERR(reg_rule)) {
+		/* We will disable all channels that do not match our
+		 * received regulatory rule unless the hint is coming
+		 * from a Country IE and the Country IE had no information
+		 * about a band. The IEEE 802.11 spec allows for an AP
+		 * to send only a subset of the regulatory rules allowed,
+		 * so an AP in the US that only supports 2.4 GHz may only send
+		 * a country IE with information for the 2.4 GHz band
+		 * while 5 GHz is still supported.
+		 */
+		if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
+		    PTR_ERR(reg_rule) == -ERANGE)
+			return;
+
+		if (lr->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
+		    request_wiphy && request_wiphy == wiphy &&
+		    request_wiphy->regulatory_flags & REGULATORY_STRICT_REG) {
+			pr_debug("Disabling freq %d.%03d MHz for good\n",
+				 chan->center_freq, chan->freq_offset);
+			chan->orig_flags |= IEEE80211_CHAN_DISABLED;
+			chan->flags = chan->orig_flags;
+		} else {
+			pr_debug("Disabling freq %d.%03d MHz\n",
+				 chan->center_freq, chan->freq_offset);
+			chan->flags |= IEEE80211_CHAN_DISABLED;
+		}
+		return;
+	}
+
+	handle_channel_single_rule(wiphy, initiator, chan, flags, lr,
+				   request_wiphy, reg_rule);
+}
+
 static void handle_band(struct wiphy *wiphy,
 			enum nl80211_reg_initiator initiator,
 			struct ieee80211_supported_band *sband)