mesh: Ignore crowded peer

The "Accepting Additional Mesh Peerings bit == 0" means the peer cannot
accept any more peers, so suppress attempt to open a connection to such
a peer.

Signed-off-by: Masashi Honma <masashi.honma@gmail.com>

src/common/ieee802_11_defs.h

@@ -1337,6 +1337,14 @@ enum wifi_display_subelem {
 #define MESH_PATH_PROTOCOL_VENDOR	255
 #define MESH_PATH_METRIC_AIRTIME	1
 #define MESH_PATH_METRIC_VENDOR		255
+/* IEEE 802.11s - Mesh Capability */
+#define MESH_CAP_ACCEPT_ADDITIONAL_PEER	BIT(0)
+#define MESH_CAP_MCCA_SUPPORTED		BIT(1)
+#define MESH_CAP_MCCA_ENABLED		BIT(2)
+#define MESH_CAP_FORWARDING		BIT(3)
+#define MESH_CAP_MBCA_ENABLED		BIT(4)
+#define MESH_CAP_TBTT_ADJUSTING		BIT(5)
+#define MESH_CAP_MESH_PS_LEVEL		BIT(6)
 
 enum plink_action_field {
 	PLINK_OPEN = 1,

wpa_supplicant/mesh_mpm.c

@@ -649,6 +649,14 @@ static struct sta_info * mesh_mpm_add_peer(struct wpa_supplicant *wpa_s,
 	struct sta_info *sta;
 	int ret;
 
+	if (elems->mesh_config_len >= 7 &&
+	    !(elems->mesh_config[6] & MESH_CAP_ACCEPT_ADDITIONAL_PEER)) {
+		wpa_msg(wpa_s, MSG_DEBUG,
+			"mesh: Ignore a crowded peer " MACSTR,
+			MAC2STR(addr));
+		return NULL;
+	}
+
 	sta = ap_get_sta(data, addr);
 	if (!sta) {
 		sta = ap_sta_add(data, addr);