Add an optional set_mode() driver_ops handler for setting mode before keys

A bug just got reported as a result of this for mac80211 drivers.

https://bugzilla.redhat.com/show_bug.cgi?id=459399

The basic problem is that since taking the device down clears the keys
from the driver on many mac80211-based cards, and since the mode gets
set _after_ the keys have been set in the driver, the keys get cleared
on a mode switch and the resulting association is wrong.  The report is
about ad-hoc mode specifically, but this could happen when switching
from adhoc back to managed mode.

src/drivers/driver.h

@@ -929,6 +929,20 @@ struct wpa_driver_ops {
 	 * Returns: 0 on success, -1 on failure
 	 */
 	int (*set_probe_req_ie)(void *, const u8 *ies, size_t ies_len);
+
+ 	/**
+	 * set_mode - Request driver to set the operating mode
+	 * @priv: private driver interface data
+	 * @mode: Operation mode (infra/ibss) IEEE80211_MODE_*
+	 *
+	 * This handler will be called before any key configuration and call to
+	 * associate() handler in order to allow the operation mode to be
+	 * configured as early as possible. This information is also available
+	 * in associate() params and as such, some driver wrappers may not need
+	 * to implement set_mode() handler.
+	 * Returns: 0 on success, -1 on failure
+	 */
+	int (*set_mode)(void *priv, int mode);
 };
 
 /**

src/drivers/driver_ndis.c

@@ -2829,5 +2829,7 @@ const struct wpa_driver_ops wpa_driver_ndis_ops = {
 	NULL /* mlme_remove_sta */,
 	NULL /* update_ft_ies */,
 	NULL /* send_ft_action */,
-	wpa_driver_ndis_get_scan_results
+	wpa_driver_ndis_get_scan_results,
+	NULL /* set_probe_req_ie */,
+	NULL /* set_mode */
 };

src/drivers/driver_nl80211.c

@@ -2226,8 +2226,6 @@ static int wpa_driver_nl80211_associate(
 	    wpa_driver_nl80211_set_bssid(drv, NULL) < 0)
 		ret = -1;
 
-	if (wpa_driver_nl80211_set_mode(drv, params->mode) < 0)
-		ret = -1;
 	/* TODO: should consider getting wpa version and cipher/key_mgmt suites
 	 * from configuration, not from here, where only the selected suite is
 	 * available */
@@ -2859,6 +2857,7 @@ const struct wpa_driver_ops wpa_driver_nl80211_ops = {
 	.get_scan_results2 = wpa_driver_nl80211_get_scan_results,
 	.deauthenticate = wpa_driver_nl80211_deauthenticate,
 	.disassociate = wpa_driver_nl80211_disassociate,
+	.set_mode = wpa_driver_nl80211_set_mode,
 	.associate = wpa_driver_nl80211_associate,
 	.set_auth_alg = wpa_driver_nl80211_set_auth_alg,
 	.init = wpa_driver_nl80211_init,

src/drivers/driver_test.c

@@ -982,5 +982,6 @@ const struct wpa_driver_ops wpa_driver_test_ops = {
 	NULL /* update_ft_ies */,
 	NULL /* send_ft_action */,
 	wpa_driver_test_get_scan_results2,
-	NULL /* set_probe_req_ie */
+	NULL /* set_probe_req_ie */,
+	NULL /* set_mode */
 };

src/drivers/driver_wext.c

@@ -2206,8 +2206,6 @@ int wpa_driver_wext_associate(void *priv,
 	    wpa_driver_wext_set_bssid(drv, NULL) < 0)
 		ret = -1;
 
-	if (wpa_driver_wext_set_mode(drv, params->mode) < 0)
-		ret = -1;
 	/* TODO: should consider getting wpa version and cipher/key_mgmt suites
 	 * from configuration, not from here, where only the selected suite is
 	 * available */
@@ -2782,6 +2780,7 @@ const struct wpa_driver_ops wpa_driver_wext_ops = {
 	.get_scan_results2 = wpa_driver_wext_get_scan_results,
 	.deauthenticate = wpa_driver_wext_deauthenticate,
 	.disassociate = wpa_driver_wext_disassociate,
+	.set_mode = wpa_driver_wext_set_mode,
 	.associate = wpa_driver_wext_associate,
 	.set_auth_alg = wpa_driver_wext_set_auth_alg,
 	.init = wpa_driver_wext_init,

wpa_supplicant/wpa_supplicant.c

@@ -937,6 +937,11 @@ void wpa_supplicant_associate(struct wpa_supplicant *wpa_s,
 	 * previous association. */
 	wpa_sm_set_assoc_wpa_ie(wpa_s->wpa, NULL, 0);
 
+	if (wpa_drv_set_mode(wpa_s, ssid->mode)) {
+		wpa_printf(MSG_WARNING, "Failed to set operating mode");
+		assoc_failed = 1;
+	}
+
 #ifdef IEEE8021X_EAPOL
 	if (ssid->key_mgmt & WPA_KEY_MGMT_IEEE8021X_NO_WPA) {
 		if (ssid->leap) {

wpa_supplicant/wpa_supplicant_i.h

@@ -448,6 +448,14 @@ static inline int wpa_drv_set_wpa(struct wpa_supplicant *wpa_s, int enabled)
 	return 0;
 }
 
+static inline int wpa_drv_set_mode(struct wpa_supplicant *wpa_s, int mode)
+{
+	if (wpa_s->driver->set_mode) {
+		return wpa_s->driver->set_mode(wpa_s->drv_priv, mode);
+	}
+	return 0;
+}
+
 static inline int wpa_drv_associate(struct wpa_supplicant *wpa_s,
 				    struct wpa_driver_associate_params *params)
 {