[PATCH] nl80211: Do not change type to station on P2P interfaces

[Ilan Peer]

It is possible that when trying to remove a dynamically added interface,
changing its type to station mode is not possible (since the kernel
does not support so in its interface combinations).

Since P2P interfaces are always dynamically added, avoid changing their type
to station in the deinit_ap() and deinit_p2p_client() nl80211 callbacks,
assuming that the interface is about to be removed.

Signed-hostap: Ilan Peer <ilan.peer at intel.com>
---
 src/drivers/driver.h         |   10 ++++++----
 src/drivers/driver_nl80211.c |   19 +++++++++++++++----
 2 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/src/drivers/driver.h b/src/drivers/driver.h
index d78bdd0..a440166 100644
--- a/src/drivers/driver.h
+++ b/src/drivers/driver.h
@@ -2161,8 +2161,9 @@ struct wpa_driver_ops {
 	 * Returns: 0 on success, -1 on failure (or if not supported)
 	 *
 	 * This optional function can be used to disable AP mode related
-	 * configuration and change the driver mode to station mode to allow
-	 * normal station operations like scanning to be completed.
+	 * configuration. If the interface was not dynamically added,
+	 * change the driver mode to station mode to allow  normal station
+	 * operations like scanning to be completed.
 	 */
 	int (*deinit_ap)(void *priv);
 
@@ -2171,8 +2172,9 @@ struct wpa_driver_ops {
 	 * @priv: Private driver interface data
 	 * Returns: 0 on success, -1 on failure (or if not supported)
 	 *
-	 * This optional function can be used to disable P2P client mode. It
-	 * can be used to change the interface type back to station mode.
+	 * This optional function can be used to disable P2P client mode. If the
+	 * interface was not dynamically added, change the interface type back
+	 * to station mode.
 	 */
 	int (*deinit_p2p_cli)(void *priv);
 
diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index 2f30cda..5737338 100644
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -197,6 +197,7 @@ struct i802_bss {
 	u8 addr[ETH_ALEN];
 
 	int freq;
+	int if_dynamic;
 
 	void *ctx;
 	struct nl_handle *nl_preq, *nl_mgmt;
@@ -4010,15 +4011,14 @@ wpa_driver_nl80211_finish_drv_init(struct wpa_driver_nl80211_data *drv)
 #endif /* HOSTAPD */
 	struct i802_bss *bss = &drv->first_bss;
 	int send_rfkill_event = 0;
-	int dynamic_if;
 
 	drv->ifindex = if_nametoindex(bss->ifname);
 	bss->ifindex = drv->ifindex;
 	bss->wdev_id = drv->global->if_add_wdevid;
 	bss->wdev_id_set = drv->global->if_add_wdevid_set;
 
-	dynamic_if = drv->ifindex == drv->global->if_add_ifindex;
-	dynamic_if = dynamic_if || drv->global->if_add_wdevid_set;
+	bss->if_dynamic = drv->ifindex == drv->global->if_add_ifindex;
+	bss->if_dynamic = bss->if_dynamic || drv->global->if_add_wdevid_set;
 	drv->global->if_add_wdevid_set = 0;
 
 	if (wpa_driver_nl80211_capa(drv))
@@ -4028,7 +4028,7 @@ wpa_driver_nl80211_finish_drv_init(struct wpa_driver_nl80211_data *drv)
 		   bss->ifname, drv->phyname);
 
 #ifndef HOSTAPD
-	if (dynamic_if)
+	if (bss->if_dynamic)
 		nlmode = nl80211_get_ifmode(bss);
 
 	/*
@@ -9530,6 +9530,12 @@ static int wpa_driver_nl80211_deinit_ap(void *priv)
 	if (!is_ap_interface(drv->nlmode))
 		return -1;
 	wpa_driver_nl80211_del_beacon(drv);
+
+	/* If the P2P GO interface was dynamically added, then it is
+	 * possible that the interface change to station is not possible */
+	if ((drv->nlmode == NL80211_IFTYPE_P2P_GO) && bss->if_dynamic)
+		return 0;
+
 	return wpa_driver_nl80211_set_mode(priv, NL80211_IFTYPE_STATION);
 }
 
@@ -9552,6 +9558,11 @@ static int wpa_driver_nl80211_deinit_p2p_cli(void *priv)
 	struct wpa_driver_nl80211_data *drv = bss->drv;
 	if (drv->nlmode != NL80211_IFTYPE_P2P_CLIENT)
 		return -1;
+
+	/* If the P2P Client interface was dynamically added, then it is
+	 * possible that the interface change to station is not possible */
+	if (bss->if_dynamic)
+		return 0;
 	return wpa_driver_nl80211_set_mode(priv, NL80211_IFTYPE_STATION);
 }
 
-- 
1.7.10.4