batman-adv: keep track of when unicast packets are sent

To enable ELP to send probing packets over wireless links
only if needed, batman-adv must keep track of the last time
it sent a unicast packet towards every neighbour.

For this purpose a 2 main changes are introduced:
1) a new member of the elp_neigh_node structure stores the
   last time a unicast packet was sent towards this neighbour;
2) a wrapper function for sending unicast packets is
   implemented. This function will simply update the member
   describe din point 1) and then forward the packet to the
   real sending routine.

Point 2) implies that any code-path leading to a unicast
sending now has to use the new wrapper.

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

1 files changed, 48 insertions, 7 deletions

diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index caff32cf6fe7..3ce06e0a91b1 100644
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -49,16 +49,30 @@
 
 static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
 
-/* send out an already prepared packet to the given address via the
- * specified batman interface
+/**
+ * batadv_send_skb_packet - send an already prepared packet
+ * @skb: the packet to send
+ * @hard_iface: the interface to use to send the broadcast packet
+ * @dst_addr: the payload destination
+ *
+ * Send out an already prepared packet to the given neighbor or broadcast it
+ * using the specified interface. Either hard_iface or neigh_node must be not
+ * NULL.
+ * If neigh_node is NULL, then the packet is broadcasted using hard_iface,
+ * otherwise it is sent as unicast to the given neighbor.
+ *
+ * Return: NET_TX_DROP in case of error or the result of dev_queue_xmit(skb)
+ * otherwise
  */
 int batadv_send_skb_packet(struct sk_buff *skb,
 			   struct batadv_hard_iface *hard_iface,
 			   const u8 *dst_addr)
 {
-	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+	struct batadv_priv *bat_priv;
 	struct ethhdr *ethhdr;
 
+	bat_priv = netdev_priv(hard_iface->soft_iface);
+
 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
 		goto send_skb_err;
 
@@ -100,6 +114,35 @@ send_skb_err:
 	return NET_XMIT_DROP;
 }
 
+int batadv_send_broadcast_skb(struct sk_buff *skb,
+			      struct batadv_hard_iface *hard_iface)
+{
+	return batadv_send_skb_packet(skb, hard_iface, batadv_broadcast_addr);
+}
+
+int batadv_send_unicast_skb(struct sk_buff *skb,
+			    struct batadv_neigh_node *neigh)
+{
+#ifdef CONFIG_BATMAN_ADV_BATMAN_V
+	struct batadv_hardif_neigh_node *hardif_neigh;
+#endif
+	int ret;
+
+	ret = batadv_send_skb_packet(skb, neigh->if_incoming, neigh->addr);
+
+#ifdef CONFIG_BATMAN_ADV_BATMAN_V
+	hardif_neigh = batadv_hardif_neigh_get(neigh->if_incoming, neigh->addr);
+
+	if ((hardif_neigh) && (ret != NET_XMIT_DROP))
+		hardif_neigh->bat_v.last_unicast_tx = jiffies;
+
+	if (hardif_neigh)
+		batadv_hardif_neigh_put(hardif_neigh);
+#endif
+
+	return ret;
+}
+
 /**
  * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
  * @skb: Packet to be transmitted.
@@ -146,8 +189,7 @@ int batadv_send_skb_to_orig(struct sk_buff *skb,
 	if (recv_if && batadv_nc_skb_forward(skb, neigh_node)) {
 		ret = NET_XMIT_POLICED;
 	} else {
-		batadv_send_skb_packet(skb, neigh_node->if_incoming,
-				       neigh_node->addr);
+		batadv_send_unicast_skb(skb, neigh_node);
 		ret = NET_XMIT_SUCCESS;
 	}
 
@@ -538,8 +580,7 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 		/* send a copy of the saved skb */
 		skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 		if (skb1)
-			batadv_send_skb_packet(skb1, hard_iface,
-					       batadv_broadcast_addr);
+			batadv_send_broadcast_skb(skb1, hard_iface);
 	}
 	rcu_read_unlock();