FST: Make FST peer connection check more permissive in hostapd

Modify the FST peer connection check so it won't skip peers without MB
IEs making it more permissive for peers that didn't provide MB IEs
during association request. This can be helpful, e.g., in cases where a
STA's interface connected before it was added to the FST group. This
allows the AP to receive FST Action frames and initiate session with a
STA via STA's interface that doesn't expose MB IEs.

The adjusted FST protocol is still safe, as it protects itself in many
other ways (checking band info and it's accordance to the interfaces,
Setup IDs, connection states of the interfaces involved, etc.)
effectively avoiding all types of invalid situations.

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

src/fst/fst.c

@@ -160,7 +160,7 @@ void fst_global_del_ctrl(struct fst_ctrl_handle *h)
 void fst_rx_action(struct fst_iface *iface, const struct ieee80211_mgmt *mgmt,
 		   size_t len)
 {
-	if (fst_iface_is_connected(iface, mgmt->sa))
+	if (fst_iface_is_connected(iface, mgmt->sa, FALSE))
 		fst_session_on_action_rx(iface, mgmt, len);
 	else
 		wpa_printf(MSG_DEBUG,

src/fst/fst_ctrl_iface.c

@@ -749,7 +749,7 @@ int fst_ctrl_iface_mb_info(const u8 *addr, char *buf, size_t buflen)
 
 	foreach_fst_group(g) {
 		foreach_fst_group_iface(g, f) {
-			if (fst_iface_is_connected(f, addr)) {
+			if (fst_iface_is_connected(f, addr, TRUE)) {
 				ret += print_band(num++, f, addr,
 						  buf + ret, buflen - ret);
 			}

src/fst/fst_group.c

@@ -219,7 +219,8 @@ fst_group_get_new_iface_by_mbie_and_band_id(struct fst_group *g,
 					fst_mbie_get_peer_addr(mbie);
 
 				if (peer_addr &&
-				    fst_iface_is_connected(iface, peer_addr) &&
+				    fst_iface_is_connected(iface, peer_addr,
+							   TRUE) &&
 				    band_id == fst_iface_get_band_id(iface)) {
 					os_memcpy(iface_peer_addr, peer_addr,
 						  ETH_ALEN);

src/fst/fst_iface.c

@@ -49,12 +49,13 @@ void fst_iface_delete(struct fst_iface *i)
 }
 
 
-Boolean fst_iface_is_connected(struct fst_iface *iface, const u8 *addr)
+Boolean fst_iface_is_connected(struct fst_iface *iface, const u8 *addr,
+			       Boolean mb_only)
 {
 	struct fst_get_peer_ctx *ctx;
-	const u8 *a = fst_iface_get_peer_first(iface, &ctx, TRUE);
+	const u8 *a = fst_iface_get_peer_first(iface, &ctx, mb_only);
 
-	for (; a != NULL; a = fst_iface_get_peer_next(iface, &ctx, TRUE))
+	for (; a != NULL; a = fst_iface_get_peer_next(iface, &ctx, mb_only))
 		if (os_memcmp(addr, a, ETH_ALEN) == 0)
 			return TRUE;
 

src/fst/fst_iface.h

@@ -123,7 +123,8 @@ static inline const u8 * fst_iface_get_peer_next(struct fst_iface *i,
 	return i->iface_obj.get_peer_next(i->iface_obj.ctx, ctx, mb_only);
 }
 
-Boolean fst_iface_is_connected(struct fst_iface *iface, const u8 *addr);
+Boolean fst_iface_is_connected(struct fst_iface *iface, const u8 *addr,
+			       Boolean mb_only);
 void fst_iface_attach_mbie(struct fst_iface *i, struct wpabuf *mbie);
 enum mb_band_id fst_iface_get_band_id(struct fst_iface *i);
 

src/fst/fst_session.c

@@ -863,13 +863,15 @@ int fst_session_initiate_setup(struct fst_session *s)
 		return -EINVAL;
 	}
 
-	if (!fst_iface_is_connected(s->data.old_iface, s->data.old_peer_addr)) {
+	if (!fst_iface_is_connected(s->data.old_iface, s->data.old_peer_addr,
+				    FALSE)) {
 		fst_printf_session(s, MSG_ERROR,
 				   "The preset old peer address is not connected");
 		return -EINVAL;
 	}
 
-	if (!fst_iface_is_connected(s->data.new_iface, s->data.new_peer_addr)) {
+	if (!fst_iface_is_connected(s->data.new_iface, s->data.new_peer_addr,
+				    FALSE)) {
 		fst_printf_session(s, MSG_ERROR,
 				   "The preset new peer address is not connected");
 		return -EINVAL;
@@ -966,7 +968,8 @@ int fst_session_respond(struct fst_session *s, u8 status_code)
 		return -EINVAL;
 	}
 
-	if (!fst_iface_is_connected(s->data.old_iface, s->data.old_peer_addr)) {
+	if (!fst_iface_is_connected(s->data.old_iface,
+				    s->data.old_peer_addr, FALSE)) {
 		fst_printf_session(s, MSG_ERROR,
 				   "The preset peer address is not in the peer list");
 		return -EINVAL;