batman-adv: Distributed ARP Table - add snooping functions for ARP messages
In case of an ARP message going in or out the soft_iface, it is intercepted and
a special action is performed. In particular the DHT helper functions previously
implemented are used to store all the ARP entries belonging to the network in
order to provide a fast and unicast lookup instead of the classic broadcast
flooding mechanism.
Each node stores the entries it is responsible for (following the DHT rules) in
its soft_iface ARP table. This makes it possible to reuse the kernel data
structures and functions for ARP management.
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 859679b..1826699 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -28,6 +28,7 @@
#include "vis.h"
#include "unicast.h"
#include "bridge_loop_avoidance.h"
+#include "distributed-arp-table.h"
static int batadv_route_unicast_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if);
@@ -985,11 +986,13 @@
struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct batadv_unicast_packet *unicast_packet;
int hdr_size = sizeof(*unicast_packet);
+ bool is4addr;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
+ is4addr = unicast_packet->header.packet_type == BATADV_UNICAST_4ADDR;
/* the caller function should have already pulled 2 bytes */
- if (unicast_packet->header.packet_type == BATADV_UNICAST_4ADDR)
+ if (is4addr)
hdr_size = sizeof(struct batadv_unicast_4addr_packet);
if (batadv_check_unicast_packet(skb, hdr_size) < 0)
@@ -1000,9 +1003,17 @@
/* packet for me */
if (batadv_is_my_mac(unicast_packet->dest)) {
+ if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb,
+ hdr_size))
+ goto rx_success;
+ if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb,
+ hdr_size))
+ goto rx_success;
+
batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size,
NULL);
+rx_success:
return NET_RX_SUCCESS;
}
@@ -1038,8 +1049,17 @@
if (!new_skb)
return NET_RX_SUCCESS;
+ if (batadv_dat_snoop_incoming_arp_request(bat_priv, new_skb,
+ hdr_size))
+ goto rx_success;
+ if (batadv_dat_snoop_incoming_arp_reply(bat_priv, new_skb,
+ hdr_size))
+ goto rx_success;
+
batadv_interface_rx(recv_if->soft_iface, new_skb, recv_if,
sizeof(struct batadv_unicast_packet), NULL);
+
+rx_success:
return NET_RX_SUCCESS;
}
@@ -1131,9 +1151,16 @@
if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size))
goto out;
+ if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size))
+ goto rx_success;
+ if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size))
+ goto rx_success;
+
/* broadcast for me */
batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size,
orig_node);
+
+rx_success:
ret = NET_RX_SUCCESS;
goto out;