Re: [B.A.T.M.A.N.] [PATCHv2 4/7] batman-adv: Buffer unicast packets before forward.

On Fri, Dec 14, 2012 at 07:32:49 +0100, Martin Hundebøll wrote:

#define BATADV_NC_NODE_TIMEOUT 10000 /* Milliseconds */ +#define BATADV_NC_PATH_TIMEOUT 10000 /* Milliseconds */

Whit define doesn't seem to be used anywhere in this patch..

enum batadv_mesh_state { BATADV_MESH_INACTIVE, diff --git a/network-coding.c b/network-coding.c index e3d9f01..2388176 100644 --- a/network-coding.c +++ b/network-coding.c @@ -20,10 +20,14 @@ #include <linux/debugfs.h>

#include "main.h" +#include "hash.h" #include "network-coding.h" +#include "send.h" #include "originator.h" #include "hard-interface.h"

+static struct lock_class_key batadv_nc_coding_hash_lock_class_key;

static void batadv_nc_worker(struct work_struct *work);

/** @@ -42,10 +46,25 @@ static void batadv_nc_start_timer(struct batadv_priv *bat_priv) */ int batadv_nc_init(struct batadv_priv *bat_priv) {

• bat_priv->nc.timestamp_fwd_flush = jiffies;

• if (bat_priv->nc.coding_hash)

• return 0;
  

• bat_priv->nc.coding_hash = batadv_hash_new(128);

• if (!bat_priv->nc.coding_hash)

• goto err;
  

• batadv_hash_set_lock_class(bat_priv->nc.coding_hash,

• 		   &batadv_nc_coding_hash_lock_class_key);
  

• INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker); batadv_nc_start_timer(bat_priv);

  return 0;

+err:

• return -ENOMEM;

}

/** @@ -56,6 +75,7 @@ void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv) { atomic_set(&bat_priv->network_coding, 1); bat_priv->nc.min_tq = 200;

• bat_priv->nc.max_fwd_delay = 10;

}

/** @@ -96,6 +116,30 @@ static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node) }

/**

• • batadv_nc_path_free_ref - decrements the nc path refcounter and possibly
• • frees it
• • @nc_path: the nc node to free
• */

+static void batadv_nc_path_free_ref(struct batadv_nc_path *nc_path) +{

• if (atomic_dec_and_test(&nc_path->refcount))

• kfree_rcu(nc_path, rcu);
  

+}

+/**

• • batadv_nc_packet_free - frees nc packet
• • @nc_packet: the nc packet to free
• */

+static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet) +{

• if (nc_packet->skb)

• kfree_skb(nc_packet->skb);
  

• batadv_nc_path_free_ref(nc_packet->nc_path);
• kfree(nc_packet);

+}

+/**

• batadv_nc_to_purge_nc_node - checks whether an nc node has to be purged
• @bat_priv: the bat priv with all the soft interface information
• @nc_node: the nc node to check

@@ -112,6 +156,26 @@ static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv, }

/**

• • batadv_nc_to_purge_nc_path_coding - checks whether an nc path has timed out
• • @bat_priv: the bat priv with all the soft interface information
• • @nc_path: the nc path to check
• • Returns true if the entry has to be purged now, false otherwise
• */

+static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv,

• 			      struct batadv_nc_path *nc_path)
  

+{

• if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)

• return true;
  

• /* purge the path when no packets has been added for 10 times the

• * max_fwd_delay time
  

• */
  

• return batadv_has_timed_out(nc_path->last_valid,

• 		    bat_priv->nc.max_fwd_delay * 10);
  

+}

+/**

• batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale
• entries
• @bat_priv: the bat priv with all the soft interface information

@@ -204,6 +268,267 @@ static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv) }

/**

• • batadv_nc_purge_paths - traverse all nc paths part of the hash and remove
• • unused ones
• • @bat_priv: the bat priv with all the soft interface information
• • @hash: hash table containing the nc paths to check
• • @to_purge: function in charge to decide whether an entry has to be purged or

• •      not. This function takes the nc node as argument and has to return
    

• •      a boolean value: true is the entry has to be deleted, false
    

• •      otherwise
    

• */

+static void batadv_nc_purge_paths(struct batadv_priv *bat_priv,

• 		  struct batadv_hashtable *hash,
  

• 		  bool (*to_purge)(struct batadv_priv *,
  

• 				   struct batadv_nc_path *))
  

+{

• struct hlist_head *head;
• struct hlist_node *node, *node_tmp;
• struct batadv_nc_path *nc_path;
• spinlock_t *lock; /* Protects lists in hash */
• uint32_t i;
• for (i = 0; i < hash->size; i++) {

• head = &hash->table[i];
  

• lock = &hash->list_locks[i];
  

• /* For each nc_path in this bin */
  

• spin_lock_bh(lock);
  

• hlist_for_each_entry_safe(nc_path, node, node_tmp,
  

• 			  head, hash_entry) {
  

• 	/* if an helper function has been passed as parameter,
  

• 	 * ask it if the entry has to be purged or not
  

• 	 */
  

• 	if (to_purge && !to_purge(bat_priv, nc_path))
  

• 		continue;
  

• 	/* purging an non-empty nc_path should never happen, but
  

• 	 * is observed under high CPU load. Delay the purging
  

• 	 * until next iteration to allow the packet_list to be
  

• 	 * emptied first.
  

• 	 */
  

• 	if (!unlikely(list_empty(&nc_path->packet_list))) {
  

• 		net_ratelimited_function(printk,
  

• 					 KERN_WARNING
  

• 					 "Skipping free of non-empty nc_path (%pM -> %pM)!\n",
  

• 					 nc_path->prev_hop,
  

• 					 nc_path->next_hop);
  

• 		continue;
  

• 	}
  

• 	/* nc_path is unused, so remove it */
  

• 	batadv_dbg(BATADV_DBG_NC, bat_priv,
  

• 		   "Remove nc_path %pM -> %pM\n",
  

• 		   nc_path->prev_hop, nc_path->next_hop);
  

• 	hlist_del_rcu(node);
  

• 	batadv_nc_path_free_ref(nc_path);
  

• }
  

• spin_unlock_bh(lock);
  

• }

+}

+/**

• • batadv_nc_hash_key_gen - computes the nc_path hash key
• • @key: buffer to hold the final hash key
• • @src: source ethernet mac address going into the hash key
• • @dst: destination ethernet mac address going into the hash key
• */

+static void batadv_nc_hash_key_gen(struct batadv_nc_path *key,

• 			  const char *src,
  

• 			  const char *dst)
  

+{

• memcpy(key->prev_hop, src, sizeof(key->prev_hop));
• memcpy(key->next_hop, dst, sizeof(key->next_hop));

+}

+/**

• • batadv_nc_hash_choose - compute the hash value for an nc path
• • @data: data to hash
• • @size: size of the hash table
• • Returns the selected index in the hash table for the given data.
• */

+static uint32_t batadv_nc_hash_choose(const void *data, uint32_t size) +{

• const struct batadv_nc_path *nc_path = data;
• uint32_t hash = 0;
• hash = batadv_hash_bytes(hash, &nc_path->prev_hop,

• 		 sizeof(nc_path->prev_hop));
  

• hash = batadv_hash_bytes(hash, &nc_path->next_hop,

• 		 sizeof(nc_path->next_hop));
  

• hash += (hash << 3);
• hash ^= (hash >> 11);
• hash += (hash << 15);
• return hash % size;

+}

+/**

• • batadv_nc_hash_compare - comparing function used in the network coding hash
• • tables
• • @node: node in the local table
• • @data2: second object to compare the node to
• • Returns 1 if the two entry are the same, 0 otherwise
• */

+static int batadv_nc_hash_compare(const struct hlist_node *node,

• 		  const void *data2)
  

+{

• const struct batadv_nc_path *nc_path1, *nc_path2;
• nc_path1 = container_of(node, struct batadv_nc_path, hash_entry);
• nc_path2 = data2;
• /* Return 1 if the two keys are identical */
• if (memcmp(nc_path1->prev_hop, nc_path2->prev_hop,

•    sizeof(nc_path1->prev_hop)) != 0)
  

• return 0;
  

• if (memcmp(nc_path1->next_hop, nc_path2->next_hop,

•    sizeof(nc_path1->next_hop)) != 0)
  

• return 0;
  

• return 1;

+}

+/**

• • batadv_nc_hash_find - search for an existing nc path and return it
• • @hash: hash table containing the nc path
• • @data: search key
• • Returns the nc_path if found, NULL otherwise.
• */

+static struct batadv_nc_path * +batadv_nc_hash_find(struct batadv_hashtable *hash,

•     void *data)
  

+{

• struct hlist_head *head;
• struct hlist_node *node;
• struct batadv_nc_path *nc_path, *nc_path_tmp = NULL;
• int index;
• if (!hash)

• return NULL;
  

• index = batadv_nc_hash_choose(data, hash->size);
• head = &hash->table[index];
• rcu_read_lock();
• hlist_for_each_entry_rcu(nc_path, node, head, hash_entry) {

• if (!batadv_nc_hash_compare(node, data))
  

• 	continue;
  

• if (!atomic_inc_not_zero(&nc_path->refcount))
  

• 	continue;
  

• nc_path_tmp = nc_path;
  

• break;
  

• }
• rcu_read_unlock();
• return nc_path_tmp;

+}

+/**

• • batadv_nc_send_packet - send non-coded packet and free nc_packet struct
• • @nc_packet: the nc packet to send
• */

+static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet) +{

• batadv_send_skb_packet(nc_packet->skb,

• 	       nc_packet->neigh_node->if_incoming,
  

• 	       nc_packet->nc_path->next_hop);
  

• nc_packet->skb = NULL;
• batadv_nc_packet_free(nc_packet);

+}

+/**

• • batadv_nc_fwd_flush - Checks the timestamp of the given nc packet.
• • @bat_priv: the bat priv with all the soft interface information
• • @nc_path: the nc path the packet belongs to
• • @nc_packet: the nc packet to be checked
• • Checks whether the given nc packet has hit its forward timeout. If so, the
• • packet is no longer delayed, immediately sent and the entry deleted from the
• • queue. Has to be called with the appropriate locks.
• • Returns false as soon as the entry in the fifo queue has not been timed out
• • yet and true otherwise.
• */

+static bool batadv_nc_fwd_flush(struct batadv_priv *bat_priv,

• 		struct batadv_nc_path *nc_path,
  

• 		struct batadv_nc_packet *nc_packet)
  

+{

• unsigned long timeout = bat_priv->nc.max_fwd_delay;
• /* Packets are added to tail, so the remaining packets did not time

• * out and we can stop processing the current queue
  

• */
  

• if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE &&

•    !batadv_has_timed_out(nc_packet->timestamp, timeout))
  

• return false;
  

• /* Send packet */
• batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
• batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,

• 	   nc_packet->skb->len + ETH_HLEN);
  

• list_del(&nc_packet->list);
• batadv_nc_send_packet(nc_packet);
• return true;

+}

+/**

• • batadv_nc_process_nc_paths - traverse given nc packet pool and free timed out
• • nc packets
• • @bat_priv: the bat priv with all the soft interface information
• • @hash: to be processed hash table
• • @process_fn: Function called to process given nc packet. Should return true

• •        to encourage this function to proceed with the next packet.
    

• •        Otherwise the rest of the current queue is skipped.
    

• */

+static void +batadv_nc_process_nc_paths(struct batadv_priv *bat_priv,

• 	   struct batadv_hashtable *hash,
  

• 	   bool (*process_fn)(struct batadv_priv *,
  

• 			      struct batadv_nc_path *,
  

• 			      struct batadv_nc_packet *))
  

+{

• struct hlist_node *node;
• struct hlist_head *head;
• struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
• struct batadv_nc_path *nc_path;
• bool ret;
• int i;
• if (!hash)

• return;
  

• /* Loop hash table bins */
• for (i = 0; i < hash->size; i++) {

• head = &hash->table[i];
  

• /* Loop coding paths */
  

• rcu_read_lock();
  

• hlist_for_each_entry_rcu(nc_path, node, head, hash_entry) {
  

• 	/* Loop packets */
  

• 	spin_lock_bh(&nc_path->packet_list_lock);
  

• 	list_for_each_entry_safe(nc_packet, nc_packet_tmp,
  

• 				 &nc_path->packet_list, list) {
  

• 		ret = process_fn(bat_priv, nc_path, nc_packet);
  

• 		if (!ret)
  

• 			break;
  

• 	}
  

• 	spin_unlock_bh(&nc_path->packet_list_lock);
  

• }
  

• rcu_read_unlock();
  

• }

+}

+/**

• batadv_nc_worker - periodic task for house keeping related to network coding
• @work: kernel work struct

*/ @@ -212,12 +537,23 @@ static void batadv_nc_worker(struct work_struct *work) struct delayed_work *delayed_work; struct batadv_priv_nc *priv_nc; struct batadv_priv *bat_priv;

• unsigned long timeout;

  delayed_work = container_of(work, struct delayed_work, work); priv_nc = container_of(delayed_work, struct batadv_priv_nc, work); bat_priv = container_of(priv_nc, struct batadv_priv, nc);

  batadv_nc_purge_orig_hash(bat_priv);

• batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash,

• 	      batadv_nc_to_purge_nc_path_coding);
  

• timeout = bat_priv->nc.max_fwd_delay;

• if (batadv_has_timed_out(bat_priv->nc.timestamp_fwd_flush, timeout)) {

• batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.coding_hash,
  

• 			   batadv_nc_fwd_flush);
  

• bat_priv->nc.timestamp_fwd_flush = jiffies;
  

• }

  /* Schedule a new check */ batadv_nc_start_timer(bat_priv);

@@ -408,12 +744,163 @@ out: }

/**

• • batadv_nc_get_path - get existing nc_path or allocate a new one
• • @bat_priv: the bat priv with all the soft interface information
• • @hash: hash table containing the nc path
• • @src: ethernet source address - first half of the nc path search key
• • @dst: ethernet destination address - second half of the nc path search key
• • Returns pointer to nc_path if the path was found or created, returns NULL
• • on error.
• */

+static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv,

• 				 struct batadv_hashtable *hash,
  

• 				 uint8_t *src,
  

• 				 uint8_t *dst)
  

+{

• int hash_added;
• struct batadv_nc_path *nc_path, nc_path_key;
• batadv_nc_hash_key_gen(&nc_path_key, src, dst);
• /* Search for existing nc_path */
• nc_path = batadv_nc_hash_find(hash, (void *)&nc_path_key);
• if (nc_path) {

• /* Set timestamp to delay removal of nc_path */
  

• nc_path->last_valid = jiffies;
  

• return nc_path;
  

• }
• /* No existing nc_path was found; create a new */
• nc_path = kzalloc(sizeof(*nc_path), GFP_ATOMIC);
• if (!nc_path)

• return NULL;
  

• /* Initialize nc_path */
• INIT_LIST_HEAD(&nc_path->packet_list);
• spin_lock_init(&nc_path->packet_list_lock);
• atomic_set(&nc_path->refcount, 2);
• nc_path->last_valid = jiffies;
• memcpy(nc_path->next_hop, dst, ETH_ALEN);
• memcpy(nc_path->prev_hop, src, ETH_ALEN);
• batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_path %pM -> %pM\n",

•    nc_path->prev_hop,
  

•    nc_path->next_hop);
  

• /* Add nc_path to hash table */
• hash_added = batadv_hash_add(hash, batadv_nc_hash_compare,

• 		     batadv_nc_hash_choose, &nc_path_key,
  

• 		     &nc_path->hash_entry);
  

• if (hash_added < 0) {

• kfree(nc_path);
  

• return NULL;
  

• }
• return nc_path;

+}

+/**

• • batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding
• • @skb: skb to add to path
• • @nc_path: path to add skb to
• • @neigh_node: next hop to forward packet to
• • @packet_id: checksum to identify packet
• • Returns true if the packet was buffered or false in case of an error.
• */

+static bool batadv_nc_skb_add_to_path(struct sk_buff *skb,

• 		      struct batadv_nc_path *nc_path,
  

• 		      struct batadv_neigh_node *neigh_node,
  

• 		      __be32 packet_id)
  

+{

• struct batadv_nc_packet *nc_packet;
• nc_packet = kzalloc(sizeof(*nc_packet), GFP_ATOMIC);
• if (!nc_packet)

• return false;
  

• /* Initialize nc_packet */
• nc_packet->timestamp = jiffies;
• nc_packet->packet_id = packet_id;
• nc_packet->skb = skb;
• nc_packet->neigh_node = neigh_node;
• nc_packet->nc_path = nc_path;
• /* Add coding packet to list */
• spin_lock_bh(&nc_path->packet_list_lock);
• list_add_tail(&nc_packet->list, &nc_path->packet_list);
• spin_unlock_bh(&nc_path->packet_list_lock);
• return true;

+}

+/**

• • batadv_nc_skb_forward - try to code a packet or add it to the coding packet
• • buffer
• • @skb: data skb to forward
• • @neigh_node: next hop to forward packet to
• • @ethhdr: pointer to the ethernet header inside the skb
• • Returns true if the skb was consumed (encoded packet sent) or false otherwise
• */

+bool batadv_nc_skb_forward(struct sk_buff *skb,

• 	   struct batadv_neigh_node *neigh_node,
  

• 	   struct ethhdr *ethhdr)
  

+{

• const struct net_device *netdev = neigh_node->if_incoming->soft_iface;
• struct batadv_priv *bat_priv = netdev_priv(netdev);
• struct batadv_unicast_packet *packet;
• struct batadv_nc_path *nc_path;
• __be32 packet_id;
• u8 *payload;
• /* Check if network coding is enabled */
• if (!atomic_read(&bat_priv->network_coding))

• goto out;
  

• /* We only handle unicast packets */
• payload = skb_network_header(skb);
• packet = (struct batadv_unicast_packet *)payload;
• if (packet->header.packet_type != BATADV_UNICAST)

• goto out;
  

• /* Find or create a nc_path for this src-dst pair */
• nc_path = batadv_nc_get_path(bat_priv,

• 		     bat_priv->nc.coding_hash,
  

• 		     ethhdr->h_source,
  

• 		     neigh_node->addr);
  

• if (!nc_path)

• goto out;
  

• /* Add skb to nc_path */
• packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
• if (!batadv_nc_skb_add_to_path(skb, nc_path, neigh_node, packet_id))

• goto free_nc_path;
  

• /* Packet is consumed */
• return true;

+free_nc_path:

• batadv_nc_path_free_ref(nc_path);

+out:

• /* Packet is not consumed */
• return false;

+}

+/**

• batadv_nc_free - clean up network coding memory
• @bat_priv: the bat priv with all the soft interface information

*/ void batadv_nc_free(struct batadv_priv *bat_priv) { cancel_delayed_work_sync(&bat_priv->nc.work);

• batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL);
• batadv_hash_destroy(bat_priv->nc.coding_hash);

}

/** @@ -490,6 +977,11 @@ int batadv_nc_init_debugfs(struct batadv_priv *bat_priv) if (!file) goto out;

• file = debugfs_create_u32("max_fwd_delay", S_IRUGO | S_IWUSR, nc_dir,

• 		  &bat_priv->nc.max_fwd_delay);
  

• if (!file)

• goto out;
  

• return 0;

out: diff --git a/network-coding.h b/network-coding.h index 56dadfd..970dbde 100644 --- a/network-coding.h +++ b/network-coding.h @@ -35,6 +35,9 @@ void batadv_nc_purge_orig(struct batadv_priv *bat_priv, struct batadv_nc_node *)); void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv); void batadv_nc_init_orig(struct batadv_orig_node *orig_node); +bool batadv_nc_skb_forward(struct sk_buff *skb,

• 	   struct batadv_neigh_node *neigh_node,
  

• 	   struct ethhdr *ethhdr);
  

int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset); int batadv_nc_init_debugfs(struct batadv_priv *bat_priv);

@@ -79,6 +82,13 @@ static inline void batadv_nc_init_orig(struct batadv_orig_node *orig_node) return; }

+static inline bool batadv_nc_skb_forward(struct sk_buff *skb,

• 			 struct batadv_neigh_node *neigh_node,
  

• 			 struct ethhdr *ethhdr)
  

+{

• return false;

+}

static inline int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset) { diff --git a/routing.c b/routing.c index 0cea96b..f97cfe3 100644 --- a/routing.c +++ b/routing.c @@ -29,6 +29,7 @@ #include "unicast.h" #include "bridge_loop_avoidance.h" #include "distributed-arp-table.h" +#include "network-coding.h"

static int batadv_route_unicast_packet(struct sk_buff *skb, struct batadv_hard_iface *recv_if); @@ -865,14 +866,17 @@ static int batadv_route_unicast_packet(struct sk_buff *skb, /* decrement ttl */ unicast_packet->header.ttl--;

• /* Update stats counter */
• batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
• batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,

• 	   skb->len + ETH_HLEN);
  

• /* route it */
• if (batadv_send_skb_to_orig(skb, orig_node, recv_if))

• /* network code packet if possible */
• if (batadv_nc_skb_forward(skb, neigh_node, ethhdr)) { ret = NET_RX_SUCCESS;
• } else if (batadv_send_skb_to_orig(skb, orig_node, recv_if)) {

• ret = NET_RX_SUCCESS;
  

• /* Update stats counter */
  

• batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
  

• batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
  

• 		   skb->len + ETH_HLEN);
  

• }

out: if (neigh_node) diff --git a/types.h b/types.h index beb84f4..b34fde7 100644 --- a/types.h +++ b/types.h @@ -275,11 +275,19 @@ struct batadv_priv_dat {

• struct batadv_priv_nc - per mesh interface network coding private data
• @work: work queue callback item for cleanup
• @min_tq: only consider neighbors for encoding if neigh_tq > min_tq

• • @max_fwd_delay: maximum packet forward delay to allow coding of packets
• • @timestamp_fwd_flush: timestamp of last forward packet queue flush
• • @coding_hash: Hash table used to buffer skbs while waiting for another
• • incoming skb to code it with. Skbs are added to the buffer just before being
• • forwarded in routing.c
  */

struct batadv_priv_nc { struct delayed_work work; struct dentry *debug_dir; u8 min_tq;

• u32 max_fwd_delay;
• unsigned long timestamp_fwd_flush;
• struct batadv_hashtable *coding_hash;

};

/** @@ -441,6 +449,47 @@ struct batadv_nc_node { unsigned long last_seen; };

+/**

• • struct batadv_nc_path - network coding path
• • @hash_entry: next and prev pointer for the list handling
• • @rcu: struct used for freeing in an RCU-safe manner
• • @refcount: number of contexts the object is used by
• • @packet_list: list of buffered packets for this path
• • @packet_list_lock: access lock for packet list
• • @next_hop: next hop (destination) of path
• • @prev_hop: previous hop (source) of path
• • @last_valid: timestamp for last validation of path
• */

+struct batadv_nc_path {

• struct hlist_node hash_entry;
• struct rcu_head rcu;
• atomic_t refcount;
• struct list_head packet_list;
• spinlock_t packet_list_lock; /* Protects packet_list */
• uint8_t next_hop[ETH_ALEN];
• uint8_t prev_hop[ETH_ALEN];
• unsigned long last_valid;

+};

+/**

• • struct batadv_nc_packet - network coding packet used when coding and
• • decoding packets
• • @list: next and prev pointer for the list handling
• • @packet_id: crc32 checksum of skb data
• • @timestamp: field containing the info when the packet was added to path
• • @neigh_node: pointer to original next hop neighbor of skb
• • @skb: skb which can be encoded or used for decoding
• • @nc_path: pointer to path this nc packet is attached to
• */

+struct batadv_nc_packet {

• struct list_head list;
• __be32 packet_id;
• unsigned long timestamp;
• struct batadv_neigh_node *neigh_node;
• struct sk_buff *skb;
• struct batadv_nc_path *nc_path;

+};

/* forw_packet - structure for forw_list maintaining packets to be

•              send/forwarded
  

*/

1.8.0.2