[PATCH] libertas: specific mesh scan for mshX interface

With this patch, scanning with mshX interface will only return mesh networks. To
differentiate them, a specific mesh IE in beacons/probe responses is used. This
IE has been introduced in firmware release 5.110.14. Note:

Even though there can be at most a single mesh per channel, this scan might
return several networks in the same channel.

If all nodes in a mesh network are associated to an AP, they won't produce
beacons/probe responses, thus the network will not be listed. This will be fixed
in future firmware releases.

Scan on ethX interface is not filtered, so it will list both mesh and non-mesh
networks.
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/defs.h

@@ -156,6 +156,8 @@ static inline void lbs_dbg_hex(char *prompt, u8 * buf, int len)
 #define MRVDRV_MAX_BEACON_INTERVAL		1000
 #define MRVDRV_BEACON_INTERVAL			100
 
+#define MARVELL_MESH_IE_LENGTH		9
+
 /** INT status Bit Definition*/
 #define his_cmddnldrdy			0x01
 #define his_cardevent			0x02

drivers/net/wireless/libertas/scan.c

@@ -1099,6 +1099,12 @@ static int libertas_process_bss(struct bss_descriptor * bss,
 				memcpy(bss->wpa_ie, elem, bss->wpa_ie_len);
 				lbs_dbg_hex("process_bss: WPA IE", bss->wpa_ie,
 				            elem->len);
+			} else if (elem->len >= MARVELL_MESH_IE_LENGTH &&
+			    elem->data[0] == 0x00 &&
+			    elem->data[1] == 0x50 &&
+			    elem->data[2] == 0x43 &&
+			    elem->data[3] == 0x04) {
+				bss->mesh = 1;
 			}
 			break;
 
@@ -1611,6 +1617,10 @@ int libertas_get_scan(struct net_device *dev, struct iw_request_info *info,
 			break;
 		}
 
+		/* For mesh device, list only mesh networks */
+		if (dev == priv->mesh_dev && !iter_bss->mesh)
+			continue;
+
 		/* Prune old an old scan result */
 		stale_time = iter_bss->last_scanned + DEFAULT_MAX_SCAN_AGE;
 		if (time_after(jiffies, stale_time)) {

drivers/net/wireless/libertas/scan.h

@@ -170,6 +170,8 @@ struct bss_descriptor {
 	u8 rsn_ie[MAX_WPA_IE_LEN];
 	size_t rsn_ie_len;
 
+	u8 mesh;
+
 	struct list_head list;
 };