nl80211: sched_scan relative RSSI parameters

Add driver interface support to set sched_scan relative RSSI parameters
and to indicate driver support for this.

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

src/drivers/driver.h

@@ -495,6 +495,36 @@ struct wpa_driver_scan_params {
 	  */
 	 unsigned int duration_mandatory:1;
 
+	/**
+	 * relative_rssi_set - Whether relative RSSI parameters are set
+	 */
+	unsigned int relative_rssi_set:1;
+
+	/**
+	 * relative_rssi - Relative RSSI for reporting better BSSs
+	 *
+	 * Amount of RSSI by which a BSS should be better than the current
+	 * connected BSS to report the new BSS to user space.
+	 */
+	s8 relative_rssi;
+
+	/**
+	 * relative_adjust_band - Band to which RSSI should be adjusted
+	 *
+	 * The relative_adjust_rssi should be added to the band specified
+	 * by relative_adjust_band.
+	 */
+	enum set_band relative_adjust_band;
+
+	/**
+	 * relative_adjust_rssi - RSSI to be added to relative_adjust_band
+	 *
+	 * An amount of relative_band_rssi should be added to the BSSs that
+	 * belong to the band specified by relative_adjust_band while comparing
+	 * with other bands for BSS reporting.
+	 */
+	s8 relative_adjust_rssi;
+
 	/*
 	 * NOTE: Whenever adding new parameters here, please make sure
 	 * wpa_scan_clone_params() and wpa_scan_free_params() get updated with
@@ -1397,6 +1427,8 @@ struct wpa_driver_capa {
 #define WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA	0x0000400000000000ULL
 /** Driver supports mgmt_tx with random TX addr in connected state */
 #define WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA_CONNECTED	0x0000800000000000ULL
+/** Driver supports better BSS reporting with sched_scan in connected mode */
+#define WPA_DRIVER_FLAGS_SCHED_SCAN_RELATIVE_RSSI	0x0001000000000000ULL
 	u64 flags;
 
 #define FULL_AP_CLIENT_STATE_SUPP(drv_flags) \

src/drivers/driver_nl80211_capa.c

@@ -395,6 +395,9 @@ static void wiphy_info_ext_feature_flags(struct wiphy_info_data *info,
 	if (ext_feature_isset(ext_features, len,
 			      NL80211_EXT_FEATURE_MGMT_TX_RANDOM_TA_CONNECTED))
 		capa->flags |= WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA_CONNECTED;
+	if (ext_feature_isset(ext_features, len,
+			      NL80211_EXT_FEATURE_SCHED_SCAN_RELATIVE_RSSI))
+		capa->flags |= WPA_DRIVER_FLAGS_SCHED_SCAN_RELATIVE_RSSI;
 }
 
 

src/drivers/driver_nl80211_scan.c

@@ -562,6 +562,39 @@ int wpa_driver_nl80211_sched_scan(void *priv,
 		nla_nest_end(msg, match_sets);
 	}
 
+	if (params->relative_rssi_set) {
+		struct nl80211_bss_select_rssi_adjust rssi_adjust;
+
+		os_memset(&rssi_adjust, 0, sizeof(rssi_adjust));
+		wpa_printf(MSG_DEBUG, "nl80211: Relative RSSI: %d",
+			   params->relative_rssi);
+		if (nla_put_u32(msg, NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI,
+				params->relative_rssi))
+			goto fail;
+
+		if (params->relative_adjust_rssi) {
+			int pref_band_set = 1;
+
+			switch (params->relative_adjust_band) {
+			case WPA_SETBAND_5G:
+				rssi_adjust.band = NL80211_BAND_5GHZ;
+				break;
+			case WPA_SETBAND_2G:
+				rssi_adjust.band = NL80211_BAND_2GHZ;
+				break;
+			default:
+				pref_band_set = 0;
+				break;
+			}
+			rssi_adjust.delta = params->relative_adjust_rssi;
+
+			if (pref_band_set &&
+			    nla_put(msg, NL80211_ATTR_SCHED_SCAN_RSSI_ADJUST,
+				    sizeof(rssi_adjust), &rssi_adjust))
+				goto fail;
+		}
+	}
+
 	ret = send_and_recv_msgs(drv, msg, NULL, NULL);
 
 	/* TODO: if we get an error here, we should fall back to normal scan */