Extend hw_mode to support any band for offloaded ACS case

When device supports dual band operations with offloaded ACS, hw_mode
can now be set to any band (hw_mode=any) in order to allow ACS to select
the best channel from any band. After a channel is selected, the hw_mode
is updated for hostapd.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

hostapd/config_file.c

@@ -2539,6 +2539,8 @@ static int hostapd_config_fill(struct hostapd_config *conf,
 			conf->hw_mode = HOSTAPD_MODE_IEEE80211G;
 		else if (os_strcmp(pos, "ad") == 0)
 			conf->hw_mode = HOSTAPD_MODE_IEEE80211AD;
+		else if (os_strcmp(pos, "any") == 0)
+			conf->hw_mode = HOSTAPD_MODE_IEEE80211ANY;
 		else {
 			wpa_printf(MSG_ERROR, "Line %d: unknown hw_mode '%s'",
 				   line, pos);

hostapd/hostapd.conf

@@ -127,7 +127,9 @@ ssid=test
 
 # Operation mode (a = IEEE 802.11a, b = IEEE 802.11b, g = IEEE 802.11g,
 # ad = IEEE 802.11ad (60 GHz); a/g options are used with IEEE 802.11n, too, to
-# specify band)
+# specify band). When using ACS (see channel parameter), a special value "any"
+# can be used to indicate that any support band can be used. This special case
+# is currently supported only with drivers with which offloaded ACS is used.
 # Default: IEEE 802.11b
 hw_mode=g
 

src/ap/drv_callbacks.c

@@ -532,7 +532,7 @@ void hostapd_event_connect_failed_reason(struct hostapd_data *hapd,
 static void hostapd_acs_channel_selected(struct hostapd_data *hapd,
 					 struct acs_selected_channels *acs_res)
 {
-	int ret;
+	int ret, i;
 
 	if (hapd->iconf->channel) {
 		wpa_printf(MSG_INFO, "ACS: Channel was already set to %d",
@@ -540,6 +540,24 @@ static void hostapd_acs_channel_selected(struct hostapd_data *hapd,
 		return;
 	}
 
+	if (!hapd->iface->current_mode) {
+		for (i = 0; i < hapd->iface->num_hw_features; i++) {
+			struct hostapd_hw_modes *mode =
+				&hapd->iface->hw_features[i];
+
+			if (mode->mode == acs_res->hw_mode) {
+				hapd->iface->current_mode = mode;
+				break;
+			}
+		}
+		if (!hapd->iface->current_mode) {
+			hostapd_logger(hapd, NULL, HOSTAPD_MODULE_IEEE80211,
+				       HOSTAPD_LEVEL_WARNING,
+				       "driver selected to bad hw_mode");
+			return;
+		}
+	}
+
 	hapd->iface->freq = hostapd_hw_get_freq(hapd, acs_res->pri_channel);
 
 	if (!acs_res->pri_channel) {

src/ap/hw_features.c

@@ -895,15 +895,19 @@ int hostapd_select_hw_mode(struct hostapd_iface *iface)
 	}
 
 	if (iface->current_mode == NULL) {
-		wpa_printf(MSG_ERROR, "Hardware does not support configured "
+		if (!(iface->drv_flags & WPA_DRIVER_FLAGS_ACS_OFFLOAD) ||
-			   "mode");
+		    !(iface->drv_flags & WPA_DRIVER_FLAGS_SUPPORT_HW_MODE_ANY))
-		hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
+		{
+			wpa_printf(MSG_ERROR,
+				   "Hardware does not support configured mode");
+			hostapd_logger(iface->bss[0], NULL,
+				       HOSTAPD_MODULE_IEEE80211,
 				       HOSTAPD_LEVEL_WARNING,
-			       "Hardware does not support configured mode "
+				       "Hardware does not support configured mode (%d) (hw_mode in hostapd.conf)",
-			       "(%d) (hw_mode in hostapd.conf)",
 				       (int) iface->conf->hw_mode);
 			return -2;
 		}
+	}
 
 	switch (hostapd_check_chans(iface)) {
 	case HOSTAPD_CHAN_VALID:

src/common/defs.h

@@ -295,6 +295,7 @@ enum hostapd_hw_mode {
 	HOSTAPD_MODE_IEEE80211G,
 	HOSTAPD_MODE_IEEE80211A,
 	HOSTAPD_MODE_IEEE80211AD,
+	HOSTAPD_MODE_IEEE80211ANY,
 	NUM_HOSTAPD_MODES
 };
 

src/common/qca-vendor.h

@@ -221,6 +221,7 @@ enum qca_wlan_vendor_acs_hw_mode {
 	QCA_ACS_MODE_IEEE80211G,
 	QCA_ACS_MODE_IEEE80211A,
 	QCA_ACS_MODE_IEEE80211AD,
+	QCA_ACS_MODE_IEEE80211ANY,
 };
 
 /**
@@ -230,10 +231,13 @@ enum qca_wlan_vendor_acs_hw_mode {
  *	management offload, a mechanism where the station's firmware
  *	does the exchange with the AP to establish the temporal keys
  *	after roaming, rather than having the user space wpa_supplicant do it.
+ * @QCA_WLAN_VENDOR_FEATURE_SUPPORT_HW_MODE_ANY: Device supports automatic
+ *	band selection based on channel selection results.
  * @NUM_QCA_WLAN_VENDOR_FEATURES: Number of assigned feature bits
  */
 enum qca_wlan_vendor_features {
 	QCA_WLAN_VENDOR_FEATURE_KEY_MGMT_OFFLOAD	= 0,
+	QCA_WLAN_VENDOR_FEATURE_SUPPORT_HW_MODE_ANY     = 1,
 	NUM_QCA_WLAN_VENDOR_FEATURES /* keep last */
 };
 

src/drivers/driver.h

@@ -1212,6 +1212,8 @@ struct wpa_driver_capa {
 #define WPA_DRIVER_FLAGS_HT_IBSS		0x0000001000000000ULL
 /** Driver supports IBSS with VHT datarates */
 #define WPA_DRIVER_FLAGS_VHT_IBSS		0x0000002000000000ULL
+/** Driver supports automatic band selection */
+#define WPA_DRIVER_FLAGS_SUPPORT_HW_MODE_ANY	0x0000004000000000ULL
 	u64 flags;
 
 #define WPA_DRIVER_SMPS_MODE_STATIC			0x00000001
@@ -4563,6 +4565,7 @@ union wpa_event_data {
 	 * @ch_width: Selected Channel width by driver. Driver may choose to
 	 *	change hostapd configured ACS channel width due driver internal
 	 *	channel restrictions.
+	 * hw_mode: Selected band (used with hw_mode=any)
 	 */
 	struct acs_selected_channels {
 		u8 pri_channel;
@@ -4570,6 +4573,7 @@ union wpa_event_data {
 		u8 vht_seg0_center_ch;
 		u8 vht_seg1_center_ch;
 		u16 ch_width;
+		enum hostapd_hw_mode hw_mode;
 	} acs_selected_channels;
 };
 

src/drivers/driver_nl80211.c

@@ -8365,6 +8365,8 @@ static int hw_mode_to_qca_acs(enum hostapd_hw_mode hw_mode)
 		return QCA_ACS_MODE_IEEE80211A;
 	case HOSTAPD_MODE_IEEE80211AD:
 		return QCA_ACS_MODE_IEEE80211AD;
+	case HOSTAPD_MODE_IEEE80211ANY:
+		return QCA_ACS_MODE_IEEE80211ANY;
 	default:
 		return -1;
 	}

src/drivers/driver_nl80211_capa.c

@@ -813,6 +813,9 @@ static void qca_nl80211_get_features(struct wpa_driver_nl80211_data *drv)
 
 	if (check_feature(QCA_WLAN_VENDOR_FEATURE_KEY_MGMT_OFFLOAD, &info))
 		drv->capa.flags |= WPA_DRIVER_FLAGS_KEY_MGMT_OFFLOAD;
+
+	if (check_feature(QCA_WLAN_VENDOR_FEATURE_SUPPORT_HW_MODE_ANY, &info))
+		drv->capa.flags |= WPA_DRIVER_FLAGS_SUPPORT_HW_MODE_ANY;
 }
 
 

src/drivers/driver_nl80211_event.c

@@ -1491,6 +1491,25 @@ static void qca_nl80211_avoid_freq(struct wpa_driver_nl80211_data *drv,
 }
 
 
+static enum hostapd_hw_mode get_qca_hw_mode(u8 hw_mode)
+{
+	switch (hw_mode) {
+	case QCA_ACS_MODE_IEEE80211B:
+		return HOSTAPD_MODE_IEEE80211B;
+	case QCA_ACS_MODE_IEEE80211G:
+		return HOSTAPD_MODE_IEEE80211G;
+	case QCA_ACS_MODE_IEEE80211A:
+		return HOSTAPD_MODE_IEEE80211A;
+	case QCA_ACS_MODE_IEEE80211AD:
+		return HOSTAPD_MODE_IEEE80211AD;
+	case QCA_ACS_MODE_IEEE80211ANY:
+		return HOSTAPD_MODE_IEEE80211ANY;
+	default:
+		return NUM_HOSTAPD_MODES;
+	}
+}
+
+
 static void qca_nl80211_acs_select_ch(struct wpa_driver_nl80211_data *drv,
 				   const u8 *data, size_t len)
 {
@@ -1520,14 +1539,28 @@ static void qca_nl80211_acs_select_ch(struct wpa_driver_nl80211_data *drv,
 	if (tb[QCA_WLAN_VENDOR_ATTR_ACS_CHWIDTH])
 		event.acs_selected_channels.ch_width =
 			nla_get_u16(tb[QCA_WLAN_VENDOR_ATTR_ACS_CHWIDTH]);
+	if (tb[QCA_WLAN_VENDOR_ATTR_ACS_HW_MODE]) {
+		u8 hw_mode = nla_get_u8(tb[QCA_WLAN_VENDOR_ATTR_ACS_HW_MODE]);
+
+		event.acs_selected_channels.hw_mode = get_qca_hw_mode(hw_mode);
+		if (event.acs_selected_channels.hw_mode == NUM_HOSTAPD_MODES ||
+		    event.acs_selected_channels.hw_mode ==
+		    HOSTAPD_MODE_IEEE80211ANY) {
+			wpa_printf(MSG_DEBUG,
+				   "nl80211: Invalid hw_mode %d in ACS selection event",
+				   hw_mode);
+			return;
+		}
+	}
 
 	wpa_printf(MSG_INFO,
-		   "nl80211: ACS Results: PCH: %d SCH: %d BW: %d VHT0: %d VHT1: %d",
+		   "nl80211: ACS Results: PCH: %d SCH: %d BW: %d VHT0: %d VHT1: %d HW_MODE: %d",
 		   event.acs_selected_channels.pri_channel,
 		   event.acs_selected_channels.sec_channel,
 		   event.acs_selected_channels.ch_width,
 		   event.acs_selected_channels.vht_seg0_center_ch,
-		   event.acs_selected_channels.vht_seg1_center_ch);
+		   event.acs_selected_channels.vht_seg1_center_ch,
+		   event.acs_selected_channels.hw_mode);
 
 	/* Ignore ACS channel list check for backwards compatibility */