batman-adv: introduce packet type handler array for incoming packets
The packet handler array replaces the growing switch statement, thus
dealing with incoming packets in a more efficient way. It also adds
to possibility to register packet handlers on the fly.
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index 7913272..d19b935 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -39,6 +39,7 @@
/* List manipulations on hardif_list have to be rtnl_lock()'ed,
* list traversals just rcu-locked */
struct list_head hardif_list;
+static int (*recv_packet_handler[256])(struct sk_buff *, struct hard_iface *);
char bat_routing_algo[20] = "BATMAN IV";
static struct hlist_head bat_algo_list;
@@ -46,11 +47,15 @@
struct workqueue_struct *bat_event_workqueue;
+static void recv_handler_init(void);
+
static int __init batman_init(void)
{
INIT_LIST_HEAD(&hardif_list);
INIT_HLIST_HEAD(&bat_algo_list);
+ recv_handler_init();
+
bat_iv_init();
/* the name should not be longer than 10 chars - see
@@ -179,6 +184,122 @@
return 0;
}
+static int recv_unhandled_packet(struct sk_buff *skb,
+ struct hard_iface *recv_if)
+{
+ return NET_RX_DROP;
+}
+
+/* incoming packets with the batman ethertype received on any active hard
+ * interface
+ */
+int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *ptype, struct net_device *orig_dev)
+{
+ struct bat_priv *bat_priv;
+ struct batman_ogm_packet *batman_ogm_packet;
+ struct hard_iface *hard_iface;
+ uint8_t idx;
+ int ret;
+
+ hard_iface = container_of(ptype, struct hard_iface, batman_adv_ptype);
+ skb = skb_share_check(skb, GFP_ATOMIC);
+
+ /* skb was released by skb_share_check() */
+ if (!skb)
+ goto err_out;
+
+ /* packet should hold at least type and version */
+ if (unlikely(!pskb_may_pull(skb, 2)))
+ goto err_free;
+
+ /* expect a valid ethernet header here. */
+ if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
+ goto err_free;
+
+ if (!hard_iface->soft_iface)
+ goto err_free;
+
+ bat_priv = netdev_priv(hard_iface->soft_iface);
+
+ if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
+ goto err_free;
+
+ /* discard frames on not active interfaces */
+ if (hard_iface->if_status != IF_ACTIVE)
+ goto err_free;
+
+ batman_ogm_packet = (struct batman_ogm_packet *)skb->data;
+
+ if (batman_ogm_packet->header.version != COMPAT_VERSION) {
+ bat_dbg(DBG_BATMAN, bat_priv,
+ "Drop packet: incompatible batman version (%i)\n",
+ batman_ogm_packet->header.version);
+ goto err_free;
+ }
+
+ /* all receive handlers return whether they received or reused
+ * the supplied skb. if not, we have to free the skb.
+ */
+ idx = batman_ogm_packet->header.packet_type;
+ ret = (*recv_packet_handler[idx])(skb, hard_iface);
+
+ if (ret == NET_RX_DROP)
+ kfree_skb(skb);
+
+ /* return NET_RX_SUCCESS in any case as we
+ * most probably dropped the packet for
+ * routing-logical reasons.
+ */
+ return NET_RX_SUCCESS;
+
+err_free:
+ kfree_skb(skb);
+err_out:
+ return NET_RX_DROP;
+}
+
+static void recv_handler_init(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(recv_packet_handler); i++)
+ recv_packet_handler[i] = recv_unhandled_packet;
+
+ /* batman originator packet */
+ recv_packet_handler[BAT_IV_OGM] = recv_bat_ogm_packet;
+ /* batman icmp packet */
+ recv_packet_handler[BAT_ICMP] = recv_icmp_packet;
+ /* unicast packet */
+ recv_packet_handler[BAT_UNICAST] = recv_unicast_packet;
+ /* fragmented unicast packet */
+ recv_packet_handler[BAT_UNICAST_FRAG] = recv_ucast_frag_packet;
+ /* broadcast packet */
+ recv_packet_handler[BAT_BCAST] = recv_bcast_packet;
+ /* vis packet */
+ recv_packet_handler[BAT_VIS] = recv_vis_packet;
+ /* Translation table query (request or response) */
+ recv_packet_handler[BAT_TT_QUERY] = recv_tt_query;
+ /* Roaming advertisement */
+ recv_packet_handler[BAT_ROAM_ADV] = recv_roam_adv;
+}
+
+int recv_handler_register(uint8_t packet_type,
+ int (*recv_handler)(struct sk_buff *,
+ struct hard_iface *))
+{
+ if (recv_packet_handler[packet_type] != &recv_unhandled_packet)
+ return -EBUSY;
+
+ recv_packet_handler[packet_type] = recv_handler;
+ return 0;
+}
+
+void recv_handler_unregister(uint8_t packet_type)
+{
+ recv_packet_handler[packet_type] = recv_unhandled_packet;
+}
+
static struct bat_algo_ops *bat_algo_get(char *name)
{
struct bat_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;