TDLS: Get TDLS related capabilities from driver

Put glue code in place to propagate TDLS related driver capabilities to
the TDLS state machine.

If the driver doesn't support capabilities, assume TDLS is supported
internally.

When TDLS is explicitly not supported, disable all user facing TDLS
operations.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Cc: Kalyan C Gaddam <chakkal@iit.edu>

src/rsn_supp/tdls.c

@@ -625,7 +625,7 @@ int wpa_tdls_recv_teardown_notify(struct wpa_sm *sm, const u8 *addr,
 	u8 *rbuf, *pos;
 	int ielen;
 
-	if (sm->tdls_disabled)
+	if (sm->tdls_disabled || !sm->tdls_supported)
 		return -1;
 
 	/* Find the node and free from the list */
@@ -1823,7 +1823,7 @@ int wpa_tdls_start(struct wpa_sm *sm, const u8 *addr)
 	struct wpa_tdls_peer *peer;
 	int tdls_prohibited = sm->tdls_prohibited;
 
-	if (sm->tdls_disabled)
+	if (sm->tdls_disabled || !sm->tdls_supported)
 		return -1;
 
 #ifdef CONFIG_TDLS_TESTING
@@ -1870,7 +1870,7 @@ int wpa_tdls_reneg(struct wpa_sm *sm, const u8 *addr)
 {
 	struct wpa_tdls_peer *peer;
 
-	if (sm->tdls_disabled)
+	if (sm->tdls_disabled || !sm->tdls_supported)
 		return -1;
 
 	for (peer = sm->tdls; peer; peer = peer->next) {
@@ -1899,8 +1899,9 @@ static void wpa_supplicant_rx_tdls(void *ctx, const u8 *src_addr,
 	wpa_hexdump(MSG_DEBUG, "TDLS: Received Data frame encapsulation",
 		    buf, len);
 
-	if (sm->tdls_disabled) {
-		wpa_printf(MSG_DEBUG, "TDLS: Discard message - TDLS disabled");
+	if (sm->tdls_disabled || !sm->tdls_supported) {
+		wpa_printf(MSG_DEBUG, "TDLS: Discard message - TDLS disabled "
+			   "or unsupported by driver");
 		return;
 	}
 
@@ -1969,6 +1970,21 @@ int wpa_tdls_init(struct wpa_sm *sm)
 		return -1;
 	}
 
+	/*
+	 * Drivers that support TDLS but don't implement the get_capa callback
+	 * are assumed to perform everything internally
+	 */
+	if (wpa_sm_tdls_get_capa(sm, &sm->tdls_supported,
+				 &sm->tdls_external_setup) < 0) {
+		sm->tdls_supported = 1;
+		sm->tdls_external_setup = 0;
+	}
+
+	wpa_printf(MSG_DEBUG, "TDLS: TDLS operation%s supported by "
+		   "driver", sm->tdls_supported ? "" : " not");
+	wpa_printf(MSG_DEBUG, "TDLS: Driver uses %s link setup",
+		   sm->tdls_external_setup ? "external" : "internal");
+
 	return 0;
 }
 

src/rsn_supp/wpa.h

@@ -56,6 +56,8 @@ struct wpa_sm_ctx {
 			      const u8 *ies, size_t ies_len);
 	int (*mark_authenticated)(void *ctx, const u8 *target_ap);
 #ifdef CONFIG_TDLS
+	int (*tdls_get_capa)(void *ctx, int *tdls_supported,
+			     int *tdls_ext_setup);
 	int (*send_tdls_mgmt)(void *ctx, const u8 *dst,
 			      u8 action_code, u8 dialog_token,
 			      u16 status_code, const u8 *buf, size_t len);

src/rsn_supp/wpa_i.h

@@ -98,6 +98,15 @@ struct wpa_sm {
 	struct wpa_tdls_peer *tdls;
 	int tdls_prohibited;
 	int tdls_disabled;
+
+	/* The driver supports TDLS */
+	int tdls_supported;
+
+	/*
+	 * The driver requires explicit discovery/setup/teardown frames sent
+	 * to it via tdls_mgmt.
+	 */
+	int tdls_external_setup;
 #endif /* CONFIG_TDLS */
 
 #ifdef CONFIG_IEEE80211R
@@ -253,6 +262,16 @@ static inline void wpa_sm_set_rekey_offload(struct wpa_sm *sm)
 }
 
 #ifdef CONFIG_TDLS
+static inline int wpa_sm_tdls_get_capa(struct wpa_sm *sm,
+				       int *tdls_supported,
+				       int *tdls_ext_setup)
+{
+	if (sm->ctx->tdls_get_capa)
+		return sm->ctx->tdls_get_capa(sm->ctx->ctx, tdls_supported,
+					      tdls_ext_setup);
+	return -1;
+}
+
 static inline int wpa_sm_send_tdls_mgmt(struct wpa_sm *sm, const u8 *dst,
 					u8 action_code, u8 dialog_token,
 					u16 status_code, const u8 *buf,

wpa_supplicant/wpa_supplicant.c

@@ -2318,6 +2318,7 @@ next_driver:
 						      &wpa_s->hw.flags);
 
 	if (wpa_drv_get_capa(wpa_s, &capa) == 0) {
+		wpa_s->drv_capa_known = 1;
 		wpa_s->drv_flags = capa.flags;
 		wpa_s->max_scan_ssids = capa.max_scan_ssids;
 		wpa_s->max_sched_scan_ssids = capa.max_sched_scan_ssids;

wpa_supplicant/wpa_supplicant_i.h

@@ -500,6 +500,7 @@ struct wpa_supplicant {
 	unsigned int network_select:1;
 	unsigned int auto_select:1;
 #endif /* CONFIG_INTERWORKING */
+	unsigned int drv_capa_known;
 
 	struct {
 		struct hostapd_hw_modes *modes;

wpa_supplicant/wpas_glue.c

@@ -525,6 +525,27 @@ static int wpa_supplicant_mark_authenticated(void *ctx, const u8 *target_ap)
 
 #ifdef CONFIG_TDLS
 
+static int wpa_supplicant_tdls_get_capa(void *ctx, int *tdls_supported,
+					int *tdls_ext_setup)
+{
+	struct wpa_supplicant *wpa_s = ctx;
+
+	*tdls_supported = 0;
+	*tdls_ext_setup = 0;
+
+	if (!wpa_s->drv_capa_known)
+		return -1;
+
+	if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_TDLS_SUPPORT)
+		*tdls_supported = 1;
+
+	if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_TDLS_EXTERNAL_SETUP)
+		*tdls_ext_setup = 1;
+
+	return 0;
+}
+
+
 static int wpa_supplicant_send_tdls_mgmt(void *ctx, const u8 *dst,
 					 u8 action_code, u8 dialog_token,
 					 u16 status_code, const u8 *buf,
@@ -700,6 +721,7 @@ int wpa_supplicant_init_wpa(struct wpa_supplicant *wpa_s)
 	ctx->mark_authenticated = wpa_supplicant_mark_authenticated;
 #endif /* CONFIG_IEEE80211R */
 #ifdef CONFIG_TDLS
+	ctx->tdls_get_capa = wpa_supplicant_tdls_get_capa;
 	ctx->send_tdls_mgmt = wpa_supplicant_send_tdls_mgmt;
 	ctx->tdls_oper = wpa_supplicant_tdls_oper;
 #endif /* CONFIG_TDLS */