batman-adv: set the isolation mark in the skb if needed

If a broadcast packet is coming from a client marked as
isolated, then mark the skb using the isolation mark so
that netfilter (or any other application) can recognise
them.

The mark is written in the skb based on the mask value:
only bits set in the mask are substitued by those in the
mark value

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

1 files changed, 16 insertions, 2 deletions

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index e126d74da6b8..c50f64337f55 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -399,9 +399,23 @@ void batadv_interface_rx(struct net_device *soft_iface,
 		batadv_tt_add_temporary_global_entry(bat_priv, orig_node,
 						     ethhdr->h_source, vid);
 
-	if (batadv_is_ap_isolated(bat_priv, ethhdr->h_source, ethhdr->h_dest,
-				  vid))
+	if (is_multicast_ether_addr(ethhdr->h_dest)) {
+		/* set the mark on broadcast packets if AP isolation is ON and
+		 * the packet is coming from an "isolated" client
+		 */
+		if (batadv_vlan_ap_isola_get(bat_priv, vid) &&
+		    batadv_tt_global_is_isolated(bat_priv, ethhdr->h_source,
+						 vid)) {
+			/* save bits in skb->mark not covered by the mask and
+			 * apply the mark on the rest
+			 */
+			skb->mark &= ~bat_priv->isolation_mark_mask;
+			skb->mark |= bat_priv->isolation_mark;
+		}
+	} else if (batadv_is_ap_isolated(bat_priv, ethhdr->h_source,
+					 ethhdr->h_dest, vid)) {
 		goto dropped;
+	}
 
 	netif_rx(skb);
 	goto out;