nl80211: Add an option to specify the BSSID to scan for

This allows scans to be optimized when a response is needed only from a
single, known BSS.

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

src/drivers/driver.h

@@ -439,6 +439,15 @@ struct wpa_driver_scan_params {
 	 */
 	 unsigned int sched_scan_plans_num;
 
+	/**
+	 * bssid - Specific BSSID to scan for
+	 *
+	 * This optional parameter can be used to replace the default wildcard
+	 * BSSID with a specific BSSID to scan for if results are needed from
+	 * only a single BSS.
+	 */
+	const u8 *bssid;
+
 	/*
 	 * NOTE: Whenever adding new parameters here, please make sure
 	 * wpa_scan_clone_params() and wpa_scan_free_params() get updated with

src/drivers/driver_nl80211_scan.c

@@ -257,6 +257,13 @@ int wpa_driver_nl80211_scan(struct i802_bss *bss,
 			goto fail;
 	}
 
+	if (params->bssid) {
+		wpa_printf(MSG_DEBUG, "nl80211: Scan for a specific BSSID: "
+			   MACSTR, MAC2STR(params->bssid));
+		if (nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN, params->bssid))
+			goto fail;
+	}
+
 	ret = send_and_recv_msgs(drv, msg, NULL, NULL);
 	msg = NULL;
 	if (ret) {

wpa_supplicant/scan.c

@@ -2259,6 +2259,17 @@ wpa_scan_clone_params(const struct wpa_driver_scan_params *src)
 			params->mac_addr_mask = mac_addr + ETH_ALEN;
 		}
 	}
+
+	if (src->bssid) {
+		u8 *bssid;
+
+		bssid = os_malloc(ETH_ALEN);
+		if (!bssid)
+			goto failed;
+		os_memcpy(bssid, src->bssid, ETH_ALEN);
+		params->bssid = bssid;
+	}
+
 	return params;
 
 failed:
@@ -2287,6 +2298,8 @@ void wpa_scan_free_params(struct wpa_driver_scan_params *params)
 	 */
 	os_free((u8 *) params->mac_addr);
 
+	os_free((u8 *) params->bssid);
+
 	os_free(params);
 }