[B.A.T.M.A.N.] [PATCH 03/14] batman-adv: introduce packet type handler array for incoming packets

Antonio Quartulli
2012-05-09T11:12:45Z

From: Marek Lindner <lindner_marek@yahoo.de>

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>
---
net/batman-adv/hard-interface.c | 113 ------------------------------------
net/batman-adv/main.c | 121 +++++++++++++++++++++++++++++++++++++++
net/batman-adv/main.h | 6 ++
3 files changed, 127 insertions(+), 113 deletions(-)

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index 47c79d7..95f869c 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -32,12 +32,6 @@

#include <linux/if_arp.h>

-
-static int batman_skb_recv(struct sk_buff *skb,
- struct net_device *dev,
- struct packet_type *ptype,
- struct net_device *orig_dev);
-
void hardif_free_rcu(struct rcu_head *rcu)
{
struct hard_iface *hard_iface;
@@ -551,113 +545,6 @@ out:
return NOTIFY_DONE;
}

-/* incoming packets with the batman ethertype received on any active hard
- * interface */
-static 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;
- 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. */
-
- switch (batman_ogm_packet->header.packet_type) {
- /* batman originator packet */
- case BAT_IV_OGM:
- ret = recv_bat_ogm_packet(skb, hard_iface);
- break;
-
- /* batman icmp packet */
- case BAT_ICMP:
- ret = recv_icmp_packet(skb, hard_iface);
- break;
-
- /* unicast packet */
- case BAT_UNICAST:
- ret = recv_unicast_packet(skb, hard_iface);
- break;
-
- /* fragmented unicast packet */
- case BAT_UNICAST_FRAG:
- ret = recv_ucast_frag_packet(skb, hard_iface);
- break;
-
- /* broadcast packet */
- case BAT_BCAST:
- ret = recv_bcast_packet(skb, hard_iface);
- break;
-
- /* vis packet */
- case BAT_VIS:
- ret = recv_vis_packet(skb, hard_iface);
- break;
- /* Translation table query (request or response) */
- case BAT_TT_QUERY:
- ret = recv_tt_query(skb, hard_iface);
- break;
- /* Roaming advertisement */
- case BAT_ROAM_ADV:
- ret = recv_roam_adv(skb, hard_iface);
- break;
- default:
- ret = NET_RX_DROP;
- }
-
- 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;
-}
-
/* This function returns true if the interface represented by ifindex is a
* 802.11 wireless device */
bool is_wifi_iface(int ifindex)
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 @@ unsigned char broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

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 @@ int is_my_mac(const uint8_t *addr)
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;
diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index d9832ac..fd83acd 100644
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -155,6 +155,12 @@ void mesh_free(struct net_device *soft_iface);
void inc_module_count(void);
void dec_module_count(void);
int is_my_mac(const uint8_t *addr);
+int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *ptype, struct net_device *orig_dev);
+int recv_handler_register(uint8_t packet_type,
+ int (*recv_handler)(struct sk_buff *,
+ struct hard_iface *));
+void recv_handler_unregister(uint8_t packet_type);
int bat_algo_register(struct bat_algo_ops *bat_algo_ops);
int bat_algo_select(struct bat_priv *bat_priv, char *name);
int bat_algo_seq_print_text(struct seq_file *seq, void *offset);
--
1.7.9.4