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

3 files changed, 19 insertions, 7 deletions

diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c
index 8bf97515a77d..c5863f499133 100644
--- a/net/batman-adv/bridge_loop_avoidance.c
+++ b/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.
diff --git a/net/batman-adv/bridge_loop_avoidance.h b/net/batman-adv/bridge_loop_avoidance.h
index e39f93acc28f..dc5227b398d4 100644
--- a/net/batman-adv/bridge_loop_avoidance.h
+++ b/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;
 }
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 6e2530b02043..a0ec0e4ada4c 100644
--- a/net/batman-adv/soft-interface.c
+++ b/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);