nl80211: Allow driver-based roam to change ESS

This extends NL80211_CMD_ROAM event processing to allow the driver to
roam to another ESS (different SSID) when using offloaded BSS selection.

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

src/drivers/driver_nl80211.h

@@ -270,5 +270,6 @@ int wpa_driver_nl80211_sched_scan(void *priv,
 int wpa_driver_nl80211_stop_sched_scan(void *priv);
 struct wpa_scan_results * wpa_driver_nl80211_get_scan_results(void *priv);
 void nl80211_dump_scan(struct wpa_driver_nl80211_data *drv);
+const u8 * nl80211_get_ie(const u8 *ies, size_t ies_len, u8 ie);
 
 #endif /* DRIVER_NL80211_H */

src/drivers/driver_nl80211_event.c

@@ -271,6 +271,7 @@ static void mlme_event_connect(struct wpa_driver_nl80211_data *drv,
 			       struct nlattr *ptk_kek)
 {
 	union wpa_event_data event;
+	const u8 *ssid;
 	u16 status_code;
 
 	if (drv->capa.flags & WPA_DRIVER_FLAGS_SME) {
@@ -331,6 +332,16 @@ static void mlme_event_connect(struct wpa_driver_nl80211_data *drv,
 	if (req_ie) {
 		event.assoc_info.req_ies = nla_data(req_ie);
 		event.assoc_info.req_ies_len = nla_len(req_ie);
+
+		if (cmd == NL80211_CMD_ROAM) {
+			ssid = nl80211_get_ie(event.assoc_info.req_ies,
+					      event.assoc_info.req_ies_len,
+					      WLAN_EID_SSID);
+			if (ssid && ssid[1] > 0 && ssid[1] <= 32) {
+				drv->ssid_len = ssid[1];
+				os_memcpy(drv->ssid, ssid + 2, ssid[1]);
+			}
+		}
 	}
 	if (resp_ie) {
 		event.assoc_info.resp_ies = nla_data(resp_ie);

src/drivers/driver_nl80211_scan.c

@@ -433,7 +433,7 @@ int wpa_driver_nl80211_stop_sched_scan(void *priv)
 }
 
 
-static const u8 * nl80211_get_ie(const u8 *ies, size_t ies_len, u8 ie)
+const u8 * nl80211_get_ie(const u8 *ies, size_t ies_len, u8 ie)
 {
 	const u8 *end, *pos;
 

wpa_supplicant/events.c

@@ -158,11 +158,32 @@ static void wpa_supplicant_update_current_bss(struct wpa_supplicant *wpa_s)
 static int wpa_supplicant_select_config(struct wpa_supplicant *wpa_s)
 {
 	struct wpa_ssid *ssid, *old_ssid;
+	u8 drv_ssid[MAX_SSID_LEN];
+	size_t drv_ssid_len;
 	int res;
 
 	if (wpa_s->conf->ap_scan == 1 && wpa_s->current_ssid) {
 		wpa_supplicant_update_current_bss(wpa_s);
-		return 0;
+
+		if (wpa_s->current_ssid->ssid_len == 0)
+			return 0; /* current profile still in use */
+		res = wpa_drv_get_ssid(wpa_s, drv_ssid);
+		if (res < 0) {
+			wpa_msg(wpa_s, MSG_INFO,
+				"Failed to read SSID from driver");
+			return 0; /* try to use current profile */
+		}
+		drv_ssid_len = res;
+
+		if (drv_ssid_len == wpa_s->current_ssid->ssid_len &&
+		    os_memcmp(drv_ssid, wpa_s->current_ssid->ssid,
+			      drv_ssid_len) == 0)
+			return 0; /* current profile still in use */
+
+		wpa_msg(wpa_s, MSG_DEBUG,
+			"Driver-initiated BSS selection changed the SSID to %s",
+			wpa_ssid_txt(drv_ssid, drv_ssid_len));
+		/* continue selecting a new network profile */
 	}
 
 	wpa_dbg(wpa_s, MSG_DEBUG, "Select network based on association "