Merge tag 'batman-adv-fix-for-davem' of git://git.open-mesh.org/linux-merge

Included changes:
- fix a bug generated by the wrong interaction between the GW feature and the
  Bridge Loop Avoidance

net/batman-adv/bridge_loop_avoidance.c

@@ -1351,6 +1351,7 @@ void bla_free(struct bat_priv *bat_priv)
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: the frame to be checked
  * @vid: the VLAN ID of the frame
+ * @is_bcast: the packet came in a broadcast packet type.
  *
  * bla_rx avoidance checks if:
  *  * we have to race for a claim
@@ -1361,7 +1362,8 @@ void bla_free(struct bat_priv *bat_priv)
  * process the skb.
  *
  */
-int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid)
+int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid,
+	   bool is_bcast)
 {
 	struct ethhdr *ethhdr;
 	struct claim search_claim, *claim = NULL;
@@ -1380,7 +1382,7 @@ int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid)
 
 	if (unlikely(atomic_read(&bat_priv->bla_num_requests)))
 		/* don't allow broadcasts while requests are in flight */
-		if (is_multicast_ether_addr(ethhdr->h_dest))
+		if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast)
 			goto handled;
 
 	memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN);
@@ -1406,8 +1408,13 @@ int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid)
 	}
 
 	/* if it is a broadcast ... */
-	if (is_multicast_ether_addr(ethhdr->h_dest)) {
-		/* ... drop it. the responsible gateway is in charge. */
+	if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) {
+		/* ... drop it. the responsible gateway is in charge.
+		 *
+		 * We need to check is_bcast because with the gateway
+		 * feature, broadcasts (like DHCP requests) may be sent
+		 * using a unicast packet type.
+		 */
 		goto handled;
 	} else {
 		/* seems the client considers us as its best gateway.

net/batman-adv/bridge_loop_avoidance.h

@@ -23,7 +23,8 @@
 #define _NET_BATMAN_ADV_BLA_H_
 
 #ifdef CONFIG_BATMAN_ADV_BLA
-int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid);
+int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid,
+	   bool is_bcast);
 int bla_tx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid);
 int bla_is_backbone_gw(struct sk_buff *skb,
 		       struct orig_node *orig_node, int hdr_size);
@@ -41,7 +42,7 @@ void bla_free(struct bat_priv *bat_priv);
 #else /* ifdef CONFIG_BATMAN_ADV_BLA */
 
 static inline int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb,
-			 short vid)
+			 short vid, bool is_bcast)
 {
 	return 0;
 }

net/batman-adv/soft-interface.c

@@ -256,7 +256,11 @@ void interface_rx(struct net_device *soft_iface,
 	struct bat_priv *bat_priv = netdev_priv(soft_iface);
 	struct ethhdr *ethhdr;
 	struct vlan_ethhdr *vhdr;
+	struct batman_header *batadv_header = (struct batman_header *)skb->data;
 	short vid __maybe_unused = -1;
+	bool is_bcast;
+
+	is_bcast = (batadv_header->packet_type == BAT_BCAST);
 
 	/* check if enough space is available for pulling, and pull */
 	if (!pskb_may_pull(skb, hdr_size))
@@ -302,7 +306,7 @@ void interface_rx(struct net_device *soft_iface,
 	/* Let the bridge loop avoidance check the packet. If will
 	 * not handle it, we can safely push it up.
 	 */
-	if (bla_rx(bat_priv, skb, vid))
+	if (bla_rx(bat_priv, skb, vid, is_bcast))
 		goto out;
 
 	netif_rx(skb);