commit 2dfbe0feb590dfebaf1e92c4006c1ae22ee482bb
Author: houbao <houbao@codeaurora.org>
Date:   Thu Dec 6 15:17:46 2018 +0800

    Subject: [PATCH] hostapd: Add max rate information into STATUS and STA
     commands
    
    These allow external programs to get max MCS, max nss, and rate
    information of an interface or a STA.

--- a/src/ap/ctrl_iface_ap.c
+++ b/src/ap/ctrl_iface_ap.c
@@ -51,6 +51,107 @@ static size_t hostapd_write_ht_mcs_bitma
 }
 
 
+static u8 hostapd_maxnss(struct hostapd_data *hapd, struct sta_info *sta)
+{
+	u8 *mcs_set = NULL;
+	u16 mcs_map;
+	u8 ht_rx_nss = 0;
+	u8 vht_rx_nss = 1;
+	u8 mcs;
+	u8 ht_supported = 0;
+	u8 vht_supported = 0;
+	int i;
+
+	if (sta) {
+		if (sta->ht_capabilities && (sta->flags & WLAN_STA_HT)) {
+			mcs_set = sta->ht_capabilities->supported_mcs_set;
+			ht_supported = 1;
+		}
+		if (sta->vht_capabilities && (sta->flags & WLAN_STA_VHT)) {
+			mcs_map = le_to_host16(sta->vht_capabilities->
+					       vht_supported_mcs_set.rx_map);
+			vht_supported = 1;
+		}
+	} else {
+		struct hostapd_config *conf = hapd->iface->conf;
+		struct hostapd_hw_modes *mode = hapd->iface->current_mode;
+
+		if (mode && conf->ieee80211ac && !hapd->conf->disable_11ac) {
+			mcs_map = mode->vht_mcs_set[4] | \
+				  (mode->vht_mcs_set[5] << 8);
+			vht_supported = 1;
+		}
+		if (mode && conf->ieee80211n && !hapd->conf->disable_11n) {
+			mcs_set = mode->mcs_set;
+			ht_supported = 1;
+		}
+	}
+	if (ht_supported && mcs_set != NULL) {
+		if (mcs_set[0])
+			ht_rx_nss++;
+		if (mcs_set[1])
+			ht_rx_nss++;
+		if (mcs_set[2])
+			ht_rx_nss++;
+		if (mcs_set[3])
+			ht_rx_nss++;
+	}
+	if (vht_supported) {
+		for (i = 7; i >= 0; i--) {
+			mcs = (mcs_map >> (2 * i)) & 0x03;
+			if (mcs != 0x03) {
+				vht_rx_nss = i + 1;
+				break;
+			}
+		}
+	}
+
+	return ht_rx_nss > vht_rx_nss ? ht_rx_nss : vht_rx_nss;
+}
+
+
+static u8 hostapd_htmaxmcs(const u8 *mcs_set)
+{
+	u8 rates[WLAN_SUPP_RATES_MAX];
+	u8 i;
+	u8 j = 0;
+
+	for (i = 0; i < WLAN_SUPP_HT_RATES_MAX; i++) {
+		if (mcs_set[i / 8] & (1 << (i % 8)))
+			rates[j++] = i;
+		if (j == WLAN_SUPP_RATES_MAX) {
+			wpa_printf(MSG_INFO,
+				   "HT extended rate set too large; using only %u rates",
+				   j);
+			break;
+		}
+	}
+	if (j <= WLAN_SUPP_RATES_MAX)
+		return rates[j - 1];
+
+	return 0;
+}
+
+
+static u8 hostapd_vhtmaxmcs(u16 rx_vht_mcs_map, u16 tx_vht_mcs_map)
+{
+	u8 rx_max_mcs, tx_max_mcs, max_mcs;
+
+	if (rx_vht_mcs_map && tx_vht_mcs_map) {
+		/* Refer to IEEE P802.11ac/D7.0 Figure 8-401bs
+		 * for VHT MCS Map definition
+		 */
+		rx_max_mcs = rx_vht_mcs_map & 0x03;
+		tx_max_mcs = tx_vht_mcs_map & 0x03;
+		max_mcs = rx_max_mcs < tx_max_mcs ? rx_max_mcs : tx_max_mcs;
+		if (max_mcs < 0x03)
+			return 7 + max_mcs;
+	}
+
+	return 0;
+}
+
+
 static int hostapd_get_sta_tx_rx(struct hostapd_data *hapd,
 				 struct sta_info *sta,
 				 char *buf, size_t buflen)
@@ -161,6 +262,38 @@ static int hostapd_get_sta_tx_rx(struct
 			len += ret;
 	}
 
+	ret = os_snprintf(buf + len, buflen - len, "max_nss=%u\n",
+			  hostapd_maxnss(hapd, sta));
+ 	if (!os_snprintf_error(buflen - len, ret))
+ 		len += ret;
+
+#ifdef CONFIG_IEEE80211AC
+	if ((sta->flags & WLAN_STA_VHT) && sta->vht_capabilities) {
+		u8 vht_maxmcs = hostapd_vhtmaxmcs(
+			le_to_host16(sta->vht_capabilities->
+				     vht_supported_mcs_set.rx_map),
+			le_to_host16(sta->vht_capabilities->
+				     vht_supported_mcs_set.tx_map));
+		ret = os_snprintf(buf + len, buflen - len, "max_vhtmcs=%u\n",
+				  vht_maxmcs);
+		if (!os_snprintf_error(buflen - len, ret))
+			len += ret;
+	}
+#endif /* CONFIG_IEEE80211AC */
+
+#ifdef CONFIG_IEEE80211N
+	if ((sta->flags & (WLAN_STA_HT | WLAN_STA_VHT)) == WLAN_STA_HT &&
+	    sta->ht_capabilities) {
+		u8 ht_maxmcs;
+
+		ht_maxmcs = hostapd_htmaxmcs(sta->ht_capabilities->
+					     supported_mcs_set);
+		ret = os_snprintf(buf + len, buflen - len, "max_mcs=%u\n",
+				  ht_maxmcs);
+		if (!os_snprintf_error(buflen - len, ret))
+			len += ret;
+	}
+#endif /* CONFIG_IEEE80211N */
 	return len;
 }
 
@@ -800,6 +933,20 @@ int hostapd_ctrl_iface_status(struct hos
 		if (os_snprintf_error(buflen - len, ret))
 			return len;
 		len += ret;
+
+		if (mode) {
+			u16 rxmap = mode->vht_mcs_set[0] |
+				(mode->vht_mcs_set[1] << 8);
+			u16 txmap = mode->vht_mcs_set[4] |
+				(mode->vht_mcs_set[5] << 8);
+
+			ret = os_snprintf(buf + len, buflen - len,
+					  "vht_max_mcs=%u\n",
+					  hostapd_vhtmaxmcs(rxmap, txmap));
+			if (os_snprintf_error(buflen - len, ret))
+				return len;
+			len += ret;
+		}
 	}
 
 	if (iface->conf->ieee80211n && !hapd->conf->disable_11n) {
@@ -834,8 +981,33 @@ int hostapd_ctrl_iface_status(struct hos
 		if (os_snprintf_error(buflen - len, ret))
 			return len;
 		len += ret;
+
+		if (mode) {
+			ret = os_snprintf(buf + len, buflen - len,
+					  "max_mcs=%u\n",
+					  hostapd_htmaxmcs(mode->mcs_set));
+			if (os_snprintf_error(buflen - len, ret))
+				return len;
+			len += ret;
+		}
 	}
 
+	if (mode && mode->rates && mode->num_rates &&
+	    mode->num_rates <= WLAN_SUPP_RATES_MAX) {
+		ret = os_snprintf(buf + len, buflen - len,
+				  "max_rate=%u\n",
+				  mode->rates[mode->num_rates - 1]);
+		if (os_snprintf_error(buflen - len, ret))
+			return len;
+		len += ret;
+	}
+
+	ret = os_snprintf(buf + len, buflen - len, "max_nss=%u\n",
+			  hostapd_maxnss(hapd, NULL));
+	if (os_snprintf_error(buflen - len, ret))
+		return len;
+	len += ret;
+
 	for (j = 0; mode && j < mode->num_channels; j++) {
 		if (mode->channels[j].freq == iface->freq) {
 			ret = os_snprintf(buf + len, buflen - len,
--- a/src/ap/sta_info.h
+++ b/src/ap/sta_info.h
@@ -46,6 +46,7 @@
 /* Maximum number of supported rates (from both Supported Rates and Extended
  * Supported Rates IEs). */
 #define WLAN_SUPP_RATES_MAX 32
+#define WLAN_SUPP_HT_RATES_MAX 77
 
 struct hostapd_data;