AP: Add op_class config item to specify 6 GHz channels uniquely

Add hostapd config option "op_class" for fixed channel selection along
with existing "channel" option. "op_class" and "channel" config options
together can specify channels across 2.4 GHz, 5 GHz, and 6 GHz bands
uniquely.

Signed-off-by: Liangwei Dong <liangwei@codeaurora.org>
Signed-off-by: Vamsi Krishna <vamsin@codeaurora.org>

hostapd/config_file.c

@@ -3136,6 +3136,8 @@ static int hostapd_config_fill(struct hostapd_config *conf,
 		}
 	} else if (os_strcmp(buf, "acs_exclude_dfs") == 0) {
 		conf->acs_exclude_dfs = atoi(pos);
+	} else if (os_strcmp(buf, "op_class") == 0) {
+		conf->op_class = atoi(pos);
 	} else if (os_strcmp(buf, "channel") == 0) {
 		if (os_strcmp(pos, "acs_survey") == 0) {
 #ifndef CONFIG_ACS

hostapd/hostapd.conf

@@ -163,6 +163,12 @@ hw_mode=g
 # which will enable the ACS survey based algorithm.
 channel=1
 
+# Global operating class (IEEE 802.11, Annex E, Table E-4)
+# This option allows hostapd to specify the operating class of the channel
+# configured with the channel parameter. channel and op_class together can
+# uniquely identify channels across different bands, including the 6 GHz band.
+#op_class=131
+
 # ACS tuning - Automatic Channel Selection
 # See: http://wireless.kernel.org/en/users/Documentation/acs
 #

src/ap/ap_config.h

@@ -875,6 +875,7 @@ struct hostapd_config {
 	u16 beacon_int;
 	int rts_threshold;
 	int fragm_threshold;
+	u8 op_class;
 	u8 channel;
 	int enable_edmg;
 	u8 edmg_channel;

src/ap/hw_features.c

@@ -961,6 +961,7 @@ out:
 int hostapd_select_hw_mode(struct hostapd_iface *iface)
 {
 	int i;
+	int freq = -1;
 
 	if (iface->num_hw_features < 1)
 		return -1;
@@ -977,9 +978,14 @@ int hostapd_select_hw_mode(struct hostapd_iface *iface)
 	}
 
 	iface->current_mode = NULL;
+	if (iface->conf->channel && iface->conf->op_class)
+		freq = ieee80211_chan_to_freq(NULL, iface->conf->op_class,
+					      iface->conf->channel);
 	for (i = 0; i < iface->num_hw_features; i++) {
 		struct hostapd_hw_modes *mode = &iface->hw_features[i];
 		if (mode->mode == iface->conf->hw_mode) {
+			if (freq > 0 && !hw_get_chan(mode, freq))
+				continue;
 			iface->current_mode = mode;
 			break;
 		}