Add support for user configurable Beacon frame data rate for AP mode

Allow configuration of Beacon frame TX rate from hostapd.conf with
"beacon_rate=xx" option. The following format is used to set
legacy/HT/VHT beacon rates:

Legacy (CCK/OFDM rates):
	beacon_rate=<legacy rate in 100 kbps>
HT:
	beacon_rate=ht:<HT MCS>
VHT:
	beacon_rate=vht:<VHT MCS>

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

hostapd/config_file.c

@@ -2756,6 +2756,40 @@ static int hostapd_config_fill(struct hostapd_config *conf,
 				   line);
 			return 1;
 		}
+	} else if (os_strcmp(buf, "beacon_rate") == 0) {
+		int val;
+
+		if (os_strncmp(pos, "ht:", 3) == 0) {
+			val = atoi(pos + 3);
+			if (val < 0 || val > 31) {
+				wpa_printf(MSG_ERROR,
+					   "Line %d: invalid beacon_rate HT-MCS %d",
+					   line, val);
+				return 1;
+			}
+			conf->rate_type = BEACON_RATE_HT;
+			conf->beacon_rate = val;
+		} else if (os_strncmp(pos, "vht:", 4) == 0) {
+			val = atoi(pos + 4);
+			if (val < 0 || val > 9) {
+				wpa_printf(MSG_ERROR,
+					   "Line %d: invalid beacon_rate VHT-MCS %d",
+					   line, val);
+				return 1;
+			}
+			conf->rate_type = BEACON_RATE_VHT;
+			conf->beacon_rate = val;
+		} else {
+			val = atoi(pos);
+			if (val < 10 || val > 10000) {
+				wpa_printf(MSG_ERROR,
+					   "Line %d: invalid legacy beacon_rate %d",
+					   line, val);
+				return 1;
+			}
+			conf->rate_type = BEACON_RATE_LEGACY;
+			conf->beacon_rate = val;
+		}
 	} else if (os_strcmp(buf, "preamble") == 0) {
 		if (atoi(pos))
 			conf->preamble = SHORT_PREAMBLE;

hostapd/hostapd.conf

@@ -227,6 +227,19 @@ fragm_threshold=-1
 #basic_rates=10 20 55 110
 #basic_rates=60 120 240
 
+# Beacon frame TX rate configuration
+# This sets the TX rate that is used to transmit Beacon frames. If this item is
+# not included, the driver default rate (likely lowest rate) is used.
+# Legacy (CCK/OFDM rates):
+#    beacon_rate=<legacy rate in 100 kbps>
+# HT:
+#    beacon_rate=ht:<HT MCS>
+# VHT:
+#    beacon_rate=vht:<VHT MCS>
+#
+# For example, beacon_rate=10 for 1 Mbps or beacon_rate=60 for 6 Mbps (OFDM).
+#beacon_rate=10
+
 # Short Preamble
 # This parameter can be used to enable optional use of short preamble for
 # frames sent at 2 Mbps, 5.5 Mbps, and 11 Mbps to improve network performance.

src/ap/ap_config.h

@@ -626,6 +626,8 @@ struct hostapd_config {
 
 	int *supported_rates;
 	int *basic_rates;
+	unsigned int beacon_rate;
+	enum beacon_rate_type rate_type;
 
 	const struct wpa_driver_ops *driver;
 	char *driver_params;

src/ap/beacon.c

@@ -1223,6 +1223,8 @@ int ieee802_11_build_ap_params(struct hostapd_data *hapd,
 	params->dtim_period = hapd->conf->dtim_period;
 	params->beacon_int = hapd->iconf->beacon_int;
 	params->basic_rates = hapd->iface->basic_rates;
+	params->beacon_rate = hapd->iconf->beacon_rate;
+	params->rate_type = hapd->iconf->rate_type;
 	params->ssid = hapd->conf->ssid.ssid;
 	params->ssid_len = hapd->conf->ssid.ssid_len;
 	if ((hapd->conf->wpa & (WPA_PROTO_WPA | WPA_PROTO_RSN)) ==

src/common/defs.h

@@ -370,4 +370,10 @@ enum wpa_radio_work_band {
 	BAND_60_GHZ = BIT(2),
 };
 
+enum beacon_rate_type {
+	BEACON_RATE_LEGACY,
+	BEACON_RATE_HT,
+	BEACON_RATE_VHT
+};
+
 #endif /* DEFS_H */

src/drivers/driver.h

@@ -964,6 +964,22 @@ struct wpa_driver_ap_params {
 	 */
 	int *basic_rates;
 
+	/**
+	 * beacon_rate: Beacon frame data rate
+	 *
+	 * This parameter can be used to set a specific Beacon frame data rate
+	 * for the BSS. The interpretation of this value depends on the
+	 * rate_type (legacy: in 100 kbps units, HT: HT-MCS, VHT: VHT-MCS). If
+	 * beacon_rate == 0 and rate_type == 0 (BEACON_RATE_LEGACY), the default
+	 * Beacon frame data rate is used.
+	 */
+	unsigned int beacon_rate;
+
+	/**
+	 * beacon_rate_type: Beacon data rate type (legacy/HT/VHT)
+	 */
+	enum beacon_rate_type rate_type;
+
 	/**
 	 * proberesp - Probe Response template
 	 *
@@ -1313,6 +1329,12 @@ struct wpa_driver_capa {
 #define WPA_DRIVER_FLAGS_P2P_LISTEN_OFFLOAD     0x0000020000000000ULL
 /** Driver supports FILS */
 #define WPA_DRIVER_FLAGS_SUPPORT_FILS		0x0000040000000000ULL
+/** Driver supports Beacon frame TX rate configuration (legacy rates) */
+#define WPA_DRIVER_FLAGS_BEACON_RATE_LEGACY	0x0000080000000000ULL
+/** Driver supports Beacon frame TX rate configuration (HT rates) */
+#define WPA_DRIVER_FLAGS_BEACON_RATE_HT		0x0000100000000000ULL
+/** Driver supports Beacon frame TX rate configuration (VHT rates) */
+#define WPA_DRIVER_FLAGS_BEACON_RATE_VHT	0x0000200000000000ULL
 	u64 flags;
 
 #define FULL_AP_CLIENT_STATE_SUPP(drv_flags) \