hostapd: Allow the first BSS in a multi-BSS setup to be removed

This moves the vif added check from core hostapd to the driver wrapper
(only driver_nl80211.c uses this) and reorders operations a bit to allow
the first BSS (vif) to be removed from a multi-BSS setup.

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

src/ap/hostapd.c

@@ -257,8 +257,7 @@ static void hostapd_free_hapd_data(struct hostapd_data *hapd)
 
 	authsrv_deinit(hapd);
 
-	if (hapd->interface_added &&
-	    hostapd_if_remove(hapd, WPA_IF_AP_BSS, hapd->conf->iface)) {
+	if (hostapd_if_remove(hapd, WPA_IF_AP_BSS, hapd->conf->iface)) {
 		wpa_printf(MSG_WARNING, "Failed to remove BSS interface %s",
 			   hapd->conf->iface);
 	}
@@ -644,7 +643,6 @@ static int hostapd_setup_bss(struct hostapd_data *hapd, int first)
 			}
 		}
 
-		hapd->interface_added = 1;
 		if (hostapd_if_add(hapd->iface->bss[0], WPA_IF_AP_BSS,
 				   hapd->conf->iface, hapd->own_addr, hapd,
 				   &hapd->drv_priv, force_ifname, if_addr,
@@ -1128,13 +1126,13 @@ hostapd_alloc_bss_data(struct hostapd_iface *hapd_iface,
 
 void hostapd_interface_deinit(struct hostapd_iface *iface)
 {
-	size_t j;
+	int j;
 
 	if (iface == NULL)
 		return;
 
 	hostapd_cleanup_iface_pre(iface);
-	for (j = 0; j < iface->num_bss; j++) {
+	for (j = iface->num_bss - 1; j >= 0; j--) {
 		struct hostapd_data *hapd = iface->bss[j];
 		hostapd_free_stas(hapd);
 		hostapd_flush_old_stations(hapd, WLAN_REASON_DEAUTH_LEAVING);

src/ap/hostapd.h

@@ -99,7 +99,6 @@ struct hostapd_data {
 	struct hostapd_iface *iface;
 	struct hostapd_config *iconf;
 	struct hostapd_bss_config *conf;
-	int interface_added; /* virtual interface added for this BSS */
 
 	u8 own_addr[ETH_ALEN];
 

src/drivers/driver_nl80211.c

@@ -218,6 +218,7 @@ struct i802_bss {
 	unsigned int added_bridge:1;
 	unsigned int in_deinit:1;
 	unsigned int wdev_id_set:1;
+	unsigned int added_if:1;
 
 	u8 addr[ETH_ALEN];
 
@@ -9383,6 +9384,7 @@ static int wpa_driver_nl80211_if_add(void *priv, enum wpa_driver_if_type type,
 		new_bss->next = drv->first_bss->next;
 		new_bss->freq = drv->first_bss->freq;
 		new_bss->ctx = bss_ctx;
+		new_bss->added_if = 1;
 		drv->first_bss->next = new_bss;
 		if (drv_priv)
 			*drv_priv = new_bss;
@@ -9410,7 +9412,7 @@ static int wpa_driver_nl80211_if_remove(struct i802_bss *bss,
 
 	wpa_printf(MSG_DEBUG, "nl80211: %s(type=%d ifname=%s) ifindex=%d",
 		   __func__, type, ifname, ifindex);
-	if (ifindex > 0)
+	if (ifindex > 0 && bss->added_if)
 		nl80211_remove_iface(drv, ifindex);
 
 #ifdef HOSTAPD
@@ -9448,6 +9450,18 @@ static int wpa_driver_nl80211_if_remove(struct i802_bss *bss,
 		if (bss)
 			wpa_printf(MSG_INFO, "nl80211: %s - could not find "
 				   "BSS %p in the list", __func__, bss);
+	} else {
+		nl80211_teardown_ap(bss);
+		wpa_driver_nl80211_del_beacon(drv);
+		nl80211_destroy_bss(bss);
+		i802_set_iface_flags(bss, 0);
+		if (drv->first_bss->next) {
+			drv->first_bss = drv->first_bss->next;
+			drv->ctx = drv->first_bss->ctx;
+			os_free(bss);
+		} else {
+			wpa_printf(MSG_DEBUG, "nl80211: No second BSS to reassign context to");
+		}
 	}
 #endif /* HOSTAPD */