Eric Lee / smarc-fsl-linux-kernel

Commit c799443ee13ef37221732839f1cca6f11c798b7a

Authored by Markus Elfring 2015-11-15 15:04:43 +0800

Committed by Antonio Quartulli 2016-01-09 20:56:00 +0800

batman-adv: Delete unnecessary checks before the function call "kfree_skb"

The kfree_skb() function tests whether its argument is NULL and then
returns immediately. Thus the test around the calls is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

Showing 3 changed files with 3 additions and 6 deletions Inline Diff

net/batman-adv/main.c
net/batman-adv/network-coding.c
net/batman-adv/send.c

net/batman-adv/main.c

Diff comments View file @ c799443

net/batman-adv/network-coding.c

Diff comments View file @ c799443

 /* Copyright (C) 2012-2015 B.A.T.M.A.N. contributors:
  *
  * Martin Hundebøll, Jeppe Ledet-Pedersen
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of version 2 of the GNU General Public
  * License as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 #include "network-coding.h"
 #include "main.h"
 #include <linux/atomic.h>
 #include <linux/bitops.h>
 #include <linux/byteorder/generic.h>
 #include <linux/compiler.h>
 #include <linux/debugfs.h>
 #include <linux/errno.h>
 #include <linux/etherdevice.h>
 #include <linux/fs.h>
 #include <linux/if_ether.h>
 #include <linux/if_packet.h>
 #include <linux/init.h>
 #include <linux/jhash.h>
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/lockdep.h>
 #include <linux/netdevice.h>
 #include <linux/printk.h>
 #include <linux/random.h>
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
 #include <linux/seq_file.h>
 #include <linux/skbuff.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/stat.h>
 #include <linux/stddef.h>
 #include <linux/string.h>
 #include <linux/workqueue.h>
 #include "hard-interface.h"
 #include "hash.h"
 #include "originator.h"
 #include "packet.h"
 #include "routing.h"
 #include "send.h"
 static struct lock_class_key batadv_nc_coding_hash_lock_class_key;
 static struct lock_class_key batadv_nc_decoding_hash_lock_class_key;
 static void batadv_nc_worker(struct work_struct *work);
 static int batadv_nc_recv_coded_packet(struct sk_buff *skb,
 				       struct batadv_hard_iface *recv_if);
 /**
  * batadv_nc_init - one-time initialization for network coding
  */
 int __init batadv_nc_init(void)
 {
 	int ret;
 	/* Register our packet type */
 	ret = batadv_recv_handler_register(BATADV_CODED,
 					   batadv_nc_recv_coded_packet);
 	return ret;
 }
 /**
  * batadv_nc_start_timer - initialise the nc periodic worker
  * @bat_priv: the bat priv with all the soft interface information
  */
 static void batadv_nc_start_timer(struct batadv_priv *bat_priv)
 {
 	queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work,
 			   msecs_to_jiffies(10));
 }
 /**
  * batadv_nc_tvlv_container_update - update the network coding tvlv container
  *  after network coding setting change
  * @bat_priv: the bat priv with all the soft interface information
  */
 static void batadv_nc_tvlv_container_update(struct batadv_priv *bat_priv)
 {
 	char nc_mode;
 	nc_mode = atomic_read(&bat_priv->network_coding);
 	switch (nc_mode) {
 	case 0:
 		batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1);
 		break;
 	case 1:
 		batadv_tvlv_container_register(bat_priv, BATADV_TVLV_NC, 1,
 					       NULL, 0);
 		break;
 	}
 }
 /**
  * batadv_nc_status_update - update the network coding tvlv container after
  *  network coding setting change
  * @net_dev: the soft interface net device
  */
 void batadv_nc_status_update(struct net_device *net_dev)
 {
 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
 	batadv_nc_tvlv_container_update(bat_priv);
 }
 /**
  * batadv_nc_tvlv_ogm_handler_v1 - process incoming nc tvlv container
  * @bat_priv: the bat priv with all the soft interface information
  * @orig: the orig_node of the ogm
  * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
  * @tvlv_value: tvlv buffer containing the gateway data
  * @tvlv_value_len: tvlv buffer length
  */
 static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
 					  struct batadv_orig_node *orig,
 					  u8 flags,
 					  void *tvlv_value, u16 tvlv_value_len)
 {
 	if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
 		clear_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities);
 	else
 		set_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities);
 }
 /**
  * batadv_nc_mesh_init - initialise coding hash table and start house keeping
  * @bat_priv: the bat priv with all the soft interface information
  */
 int batadv_nc_mesh_init(struct batadv_priv *bat_priv)
 {
 	bat_priv->nc.timestamp_fwd_flush = jiffies;
 	bat_priv->nc.timestamp_sniffed_purge = jiffies;
 	if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_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);
 	bat_priv->nc.decoding_hash = batadv_hash_new(128);
 	if (!bat_priv->nc.decoding_hash)
 		goto err;
 	batadv_hash_set_lock_class(bat_priv->nc.decoding_hash,
 				   &batadv_nc_decoding_hash_lock_class_key);
 	INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker);
 	batadv_nc_start_timer(bat_priv);
 	batadv_tvlv_handler_register(bat_priv, batadv_nc_tvlv_ogm_handler_v1,
 				     NULL, BATADV_TVLV_NC, 1,
 				     BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
 	batadv_nc_tvlv_container_update(bat_priv);
 	return 0;
 err:
 	return -ENOMEM;
 }
 /**
  * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables
  * @bat_priv: the bat priv with all the soft interface information
  */
 void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv)
 {
 	atomic_set(&bat_priv->network_coding, 0);
 	bat_priv->nc.min_tq = 200;
 	bat_priv->nc.max_fwd_delay = 10;
 	bat_priv->nc.max_buffer_time = 200;
 }
 /**
  * batadv_nc_init_orig - initialise the nc fields of an orig_node
  * @orig_node: the orig_node which is going to be initialised
  */
 void batadv_nc_init_orig(struct batadv_orig_node *orig_node)
 {
 	INIT_LIST_HEAD(&orig_node->in_coding_list);
 	INIT_LIST_HEAD(&orig_node->out_coding_list);
 	spin_lock_init(&orig_node->in_coding_list_lock);
 	spin_lock_init(&orig_node->out_coding_list_lock);
 }
 /**
  * batadv_nc_node_free_rcu - rcu callback to free an nc node and remove
  *  its refcount on the orig_node
  * @rcu: rcu pointer of the nc node
  */
 static void batadv_nc_node_free_rcu(struct rcu_head *rcu)
 {
 	struct batadv_nc_node *nc_node;
 	nc_node = container_of(rcu, struct batadv_nc_node, rcu);
 	batadv_orig_node_free_ref(nc_node->orig_node);
 	kfree(nc_node);
 }
 /**
  * batadv_nc_node_free_ref - decrements the nc node refcounter and possibly
  * frees it
  * @nc_node: the nc node to free
  */
 static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node)
 {
 	if (atomic_dec_and_test(&nc_node->refcount))
 		call_rcu(&nc_node->rcu, batadv_nc_node_free_rcu);
 }
 /**
  * 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);
-		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
  *
  * Returns true if the entry has to be purged now, false otherwise
  */
 static bool batadv_nc_to_purge_nc_node(struct batadv_priv *bat_priv,
 				       struct batadv_nc_node *nc_node)
 {
 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 		return true;
 	return batadv_has_timed_out(nc_node->last_seen, BATADV_NC_NODE_TIMEOUT);
 }
 /**
  * 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_to_purge_nc_path_decoding - 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_decoding(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_buffer time
 	 */
 	return batadv_has_timed_out(nc_path->last_valid,
 				    bat_priv->nc.max_buffer_time * 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
  * @list: list of nc nodes
  * @lock: nc node list lock
  * @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 if the entry has to be deleted, false
  *	      otherwise
  */
 static void
 batadv_nc_purge_orig_nc_nodes(struct batadv_priv *bat_priv,
 			      struct list_head *list,
 			      spinlock_t *lock,
 			      bool (*to_purge)(struct batadv_priv *,
 					       struct batadv_nc_node *))
 {
 	struct batadv_nc_node *nc_node, *nc_node_tmp;
 	/* For each nc_node in list */
 	spin_lock_bh(lock);
 	list_for_each_entry_safe(nc_node, nc_node_tmp, list, list) {
 		/* 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_node))
 			continue;
 		batadv_dbg(BATADV_DBG_NC, bat_priv,
 			   "Removing nc_node %pM -> %pM\n",
 			   nc_node->addr, nc_node->orig_node->orig);
 		list_del_rcu(&nc_node->list);
 		batadv_nc_node_free_ref(nc_node);
 	}
 	spin_unlock_bh(lock);
 }
 /**
  * batadv_nc_purge_orig - purges all nc node data attached of the given
  *  originator
  * @bat_priv: the bat priv with all the soft interface information
  * @orig_node: orig_node with the nc node entries to be purged
  * @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
  */
 void batadv_nc_purge_orig(struct batadv_priv *bat_priv,
 			  struct batadv_orig_node *orig_node,
 			  bool (*to_purge)(struct batadv_priv *,
 					   struct batadv_nc_node *))
 {
 	/* Check ingoing nc_node's of this orig_node */
 	batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->in_coding_list,
 				      &orig_node->in_coding_list_lock,
 				      to_purge);
 	/* Check outgoing nc_node's of this orig_node */
 	batadv_nc_purge_orig_nc_nodes(bat_priv, &orig_node->out_coding_list,
 				      &orig_node->out_coding_list_lock,
 				      to_purge);
 }
 /**
  * batadv_nc_purge_orig_hash - traverse entire originator hash to check if they
  *  have timed out nc nodes
  * @bat_priv: the bat priv with all the soft interface information
  */
 static void batadv_nc_purge_orig_hash(struct batadv_priv *bat_priv)
 {
 	struct batadv_hashtable *hash = bat_priv->orig_hash;
 	struct hlist_head *head;
 	struct batadv_orig_node *orig_node;
 	u32 i;
 	if (!hash)
 		return;
 	/* For each orig_node */
 	for (i = 0; i < hash->size; i++) {
 		head = &hash->table[i];
 		rcu_read_lock();
 		hlist_for_each_entry_rcu(orig_node, head, hash_entry)
 			batadv_nc_purge_orig(bat_priv, orig_node,
 					     batadv_nc_to_purge_nc_node);
 		rcu_read_unlock();
 	}
 }
 /**
  * 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_tmp;
 	struct batadv_nc_path *nc_path;
 	spinlock_t *lock; /* Protects lists in hash */
 	u32 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_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(&nc_path->hash_entry);
 			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 u32 batadv_nc_hash_choose(const void *data, u32 size)
 {
 	const struct batadv_nc_path *nc_path = data;
 	u32 hash = 0;
 	hash = jhash(&nc_path->prev_hop, sizeof(nc_path->prev_hop), hash);
 	hash = jhash(&nc_path->next_hop, sizeof(nc_path->next_hop), hash);
 	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 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, head, hash_entry) {
 		if (!batadv_nc_hash_compare(&nc_path->hash_entry, 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_sniffed_purge - Checks timestamp of given sniffed 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 sniffed (overheard) nc_packet has hit its buffering
  * timeout. If so, the packet is no longer kept 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_sniffed_purge(struct batadv_priv *bat_priv,
 				    struct batadv_nc_path *nc_path,
 				    struct batadv_nc_packet *nc_packet)
 {
 	unsigned long timeout = bat_priv->nc.max_buffer_time;
 	bool res = false;
 	lockdep_assert_held(&nc_path->packet_list_lock);
 	/* 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))
 		goto out;
 	/* purge nc packet */
 	list_del(&nc_packet->list);
 	batadv_nc_packet_free(nc_packet);
 	res = true;
 out:
 	return res;
 }
 /**
  * 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;
 	lockdep_assert_held(&nc_path->packet_list_lock);
 	/* 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_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, 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
  */
 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);
 	batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash,
 			      batadv_nc_to_purge_nc_path_decoding);
 	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;
 	}
 	if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge,
 				 bat_priv->nc.max_buffer_time)) {
 		batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash,
 					   batadv_nc_sniffed_purge);
 		bat_priv->nc.timestamp_sniffed_purge = jiffies;
 	}
 	/* Schedule a new check */
 	batadv_nc_start_timer(bat_priv);
 }
 /**
  * batadv_can_nc_with_orig - checks whether the given orig node is suitable for
  *  coding or not
  * @bat_priv: the bat priv with all the soft interface information
  * @orig_node: neighboring orig node which may be used as nc candidate
  * @ogm_packet: incoming ogm packet also used for the checks
  *
  * Returns true if:
  *  1) The OGM must have the most recent sequence number.
  *  2) The TTL must be decremented by one and only one.
  *  3) The OGM must be received from the first hop from orig_node.
  *  4) The TQ value of the OGM must be above bat_priv->nc.min_tq.
  */
 static bool batadv_can_nc_with_orig(struct batadv_priv *bat_priv,
 				    struct batadv_orig_node *orig_node,
 				    struct batadv_ogm_packet *ogm_packet)
 {
 	struct batadv_orig_ifinfo *orig_ifinfo;
 	u32 last_real_seqno;
 	u8 last_ttl;
 	orig_ifinfo = batadv_orig_ifinfo_get(orig_node, BATADV_IF_DEFAULT);
 	if (!orig_ifinfo)
 		return false;
 	last_ttl = orig_ifinfo->last_ttl;
 	last_real_seqno = orig_ifinfo->last_real_seqno;
 	batadv_orig_ifinfo_free_ref(orig_ifinfo);
 	if (last_real_seqno != ntohl(ogm_packet->seqno))
 		return false;
 	if (last_ttl != ogm_packet->ttl + 1)
 		return false;
 	if (!batadv_compare_eth(ogm_packet->orig, ogm_packet->prev_sender))
 		return false;
 	if (ogm_packet->tq < bat_priv->nc.min_tq)
 		return false;
 	return true;
 }
 /**
  * batadv_nc_find_nc_node - search for an existing nc node and return it
  * @orig_node: orig node originating the ogm packet
  * @orig_neigh_node: neighboring orig node from which we received the ogm packet
  *  (can be equal to orig_node)
  * @in_coding: traverse incoming or outgoing network coding list
  *
  * Returns the nc_node if found, NULL otherwise.
  */
 static struct batadv_nc_node
 *batadv_nc_find_nc_node(struct batadv_orig_node *orig_node,
 			struct batadv_orig_node *orig_neigh_node,
 			bool in_coding)
 {
 	struct batadv_nc_node *nc_node, *nc_node_out = NULL;
 	struct list_head *list;
 	if (in_coding)
 		list = &orig_neigh_node->in_coding_list;
 	else
 		list = &orig_neigh_node->out_coding_list;
 	/* Traverse list of nc_nodes to orig_node */
 	rcu_read_lock();
 	list_for_each_entry_rcu(nc_node, list, list) {
 		if (!batadv_compare_eth(nc_node->addr, orig_node->orig))
 			continue;
 		if (!atomic_inc_not_zero(&nc_node->refcount))
 			continue;
 		/* Found a match */
 		nc_node_out = nc_node;
 		break;
 	}
 	rcu_read_unlock();
 	return nc_node_out;
 }
 /**
  * batadv_nc_get_nc_node - retrieves an nc node or creates the entry if it was
  *  not found
  * @bat_priv: the bat priv with all the soft interface information
  * @orig_node: orig node originating the ogm packet
  * @orig_neigh_node: neighboring orig node from which we received the ogm packet
  *  (can be equal to orig_node)
  * @in_coding: traverse incoming or outgoing network coding list
  *
  * Returns the nc_node if found or created, NULL in case of an error.
  */
 static struct batadv_nc_node
 *batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
 		       struct batadv_orig_node *orig_node,
 		       struct batadv_orig_node *orig_neigh_node,
 		       bool in_coding)
 {
 	struct batadv_nc_node *nc_node;
 	spinlock_t *lock; /* Used to lock list selected by "int in_coding" */
 	struct list_head *list;
 	/* Check if nc_node is already added */
 	nc_node = batadv_nc_find_nc_node(orig_node, orig_neigh_node, in_coding);
 	/* Node found */
 	if (nc_node)
 		return nc_node;
 	nc_node = kzalloc(sizeof(*nc_node), GFP_ATOMIC);
 	if (!nc_node)
 		return NULL;
 	if (!atomic_inc_not_zero(&orig_neigh_node->refcount))
 		goto free;
 	/* Initialize nc_node */
 	INIT_LIST_HEAD(&nc_node->list);
 	ether_addr_copy(nc_node->addr, orig_node->orig);
 	nc_node->orig_node = orig_neigh_node;
 	atomic_set(&nc_node->refcount, 2);
 	/* Select ingoing or outgoing coding node */
 	if (in_coding) {
 		lock = &orig_neigh_node->in_coding_list_lock;
 		list = &orig_neigh_node->in_coding_list;
 	} else {
 		lock = &orig_neigh_node->out_coding_list_lock;
 		list = &orig_neigh_node->out_coding_list;
 	}
 	batadv_dbg(BATADV_DBG_NC, bat_priv, "Adding nc_node %pM -> %pM\n",
 		   nc_node->addr, nc_node->orig_node->orig);
 	/* Add nc_node to orig_node */
 	spin_lock_bh(lock);
 	list_add_tail_rcu(&nc_node->list, list);
 	spin_unlock_bh(lock);
 	return nc_node;
 free:
 	kfree(nc_node);
 	return NULL;
 }
 /**
  * batadv_nc_update_nc_node - updates stored incoming and outgoing nc node
  *  structs (best called on incoming OGMs)
  * @bat_priv: the bat priv with all the soft interface information
  * @orig_node: orig node originating the ogm packet
  * @orig_neigh_node: neighboring orig node from which we received the ogm packet
  *  (can be equal to orig_node)
  * @ogm_packet: incoming ogm packet
  * @is_single_hop_neigh: orig_node is a single hop neighbor
  */
 void batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
 			      struct batadv_orig_node *orig_node,
 			      struct batadv_orig_node *orig_neigh_node,
 			      struct batadv_ogm_packet *ogm_packet,
 			      int is_single_hop_neigh)
 {
 	struct batadv_nc_node *in_nc_node = NULL;
 	struct batadv_nc_node *out_nc_node = NULL;
 	/* Check if network coding is enabled */
 	if (!atomic_read(&bat_priv->network_coding))
 		goto out;
 	/* check if orig node is network coding enabled */
 	if (!test_bit(BATADV_ORIG_CAPA_HAS_NC, &orig_node->capabilities))
 		goto out;
 	/* accept ogms from 'good' neighbors and single hop neighbors */
 	if (!batadv_can_nc_with_orig(bat_priv, orig_node, ogm_packet) &&
 	    !is_single_hop_neigh)
 		goto out;
 	/* Add orig_node as in_nc_node on hop */
 	in_nc_node = batadv_nc_get_nc_node(bat_priv, orig_node,
 					   orig_neigh_node, true);
 	if (!in_nc_node)
 		goto out;
 	in_nc_node->last_seen = jiffies;
 	/* Add hop as out_nc_node on orig_node */
 	out_nc_node = batadv_nc_get_nc_node(bat_priv, orig_neigh_node,
 					    orig_node, false);
 	if (!out_nc_node)
 		goto out;
 	out_nc_node->last_seen = jiffies;
 out:
 	if (in_nc_node)
 		batadv_nc_node_free_ref(in_nc_node);
 	if (out_nc_node)
 		batadv_nc_node_free_ref(out_nc_node);
 }
 /**
  * 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,
 						 u8 *src,
 						 u8 *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;
 	ether_addr_copy(nc_path->next_hop, dst);
 	ether_addr_copy(nc_path->prev_hop, src);
 	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_random_weight_tq - scale the receivers TQ-value to avoid unfair
  *  selection of a receiver with slightly lower TQ than the other
  * @tq: to be weighted tq value
  */
 static u8 batadv_nc_random_weight_tq(u8 tq)
 {
 	u8 rand_val, rand_tq;
 	get_random_bytes(&rand_val, sizeof(rand_val));
 	/* randomize the estimated packet loss (max TQ - estimated TQ) */
 	rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq);
 	/* normalize the randomized packet loss */
 	rand_tq /= BATADV_TQ_MAX_VALUE;
 	/* convert to (randomized) estimated tq again */
 	return BATADV_TQ_MAX_VALUE - rand_tq;
 }
 /**
  * batadv_nc_memxor - XOR destination with source
  * @dst: byte array to XOR into
  * @src: byte array to XOR from
  * @len: length of destination array
  */
 static void batadv_nc_memxor(char *dst, const char *src, unsigned int len)
 {
 	unsigned int i;
 	for (i = 0; i < len; ++i)
 		dst[i] ^= src[i];
 }
 /**
  * batadv_nc_code_packets - code a received unicast_packet with an nc packet
  *  into a coded_packet and send it
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: data skb to forward
  * @ethhdr: pointer to the ethernet header inside the skb
  * @nc_packet: structure containing the packet to the skb can be coded with
  * @neigh_node: next hop to forward packet to
  *
  * Returns true if both packets are consumed, false otherwise.
  */
 static bool batadv_nc_code_packets(struct batadv_priv *bat_priv,
 				   struct sk_buff *skb,
 				   struct ethhdr *ethhdr,
 				   struct batadv_nc_packet *nc_packet,
 				   struct batadv_neigh_node *neigh_node)
 {
 	u8 tq_weighted_neigh, tq_weighted_coding, tq_tmp;
 	struct sk_buff *skb_dest, *skb_src;
 	struct batadv_unicast_packet *packet1;
 	struct batadv_unicast_packet *packet2;
 	struct batadv_coded_packet *coded_packet;
 	struct batadv_neigh_node *neigh_tmp, *router_neigh;
 	struct batadv_neigh_node *router_coding = NULL;
 	struct batadv_neigh_ifinfo *router_neigh_ifinfo = NULL;
 	struct batadv_neigh_ifinfo *router_coding_ifinfo = NULL;
 	u8 *first_source, *first_dest, *second_source, *second_dest;
 	__be32 packet_id1, packet_id2;
 	size_t count;
 	bool res = false;
 	int coding_len;
 	int unicast_size = sizeof(*packet1);
 	int coded_size = sizeof(*coded_packet);
 	int header_add = coded_size - unicast_size;
 	/* TODO: do we need to consider the outgoing interface for
 	 * coded packets?
 	 */
 	router_neigh = batadv_orig_router_get(neigh_node->orig_node,
 					      BATADV_IF_DEFAULT);
 	if (!router_neigh)
 		goto out;
 	router_neigh_ifinfo = batadv_neigh_ifinfo_get(router_neigh,
 						      BATADV_IF_DEFAULT);
 	if (!router_neigh_ifinfo)
 		goto out;
 	neigh_tmp = nc_packet->neigh_node;
 	router_coding = batadv_orig_router_get(neigh_tmp->orig_node,
 					       BATADV_IF_DEFAULT);
 	if (!router_coding)
 		goto out;
 	router_coding_ifinfo = batadv_neigh_ifinfo_get(router_coding,
 						       BATADV_IF_DEFAULT);
 	if (!router_coding_ifinfo)
 		goto out;
 	tq_tmp = router_neigh_ifinfo->bat_iv.tq_avg;
 	tq_weighted_neigh = batadv_nc_random_weight_tq(tq_tmp);
 	tq_tmp = router_coding_ifinfo->bat_iv.tq_avg;
 	tq_weighted_coding = batadv_nc_random_weight_tq(tq_tmp);
 	/* Select one destination for the MAC-header dst-field based on
 	 * weighted TQ-values.
 	 */
 	if (tq_weighted_neigh >= tq_weighted_coding) {
 		/* Destination from nc_packet is selected for MAC-header */
 		first_dest = nc_packet->nc_path->next_hop;
 		first_source = nc_packet->nc_path->prev_hop;
 		second_dest = neigh_node->addr;
 		second_source = ethhdr->h_source;
 		packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data;
 		packet2 = (struct batadv_unicast_packet *)skb->data;
 		packet_id1 = nc_packet->packet_id;
 		packet_id2 = batadv_skb_crc32(skb,
 					      skb->data + sizeof(*packet2));
 	} else {
 		/* Destination for skb is selected for MAC-header */
 		first_dest = neigh_node->addr;
 		first_source = ethhdr->h_source;
 		second_dest = nc_packet->nc_path->next_hop;
 		second_source = nc_packet->nc_path->prev_hop;
 		packet1 = (struct batadv_unicast_packet *)skb->data;
 		packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data;
 		packet_id1 = batadv_skb_crc32(skb,
 					      skb->data + sizeof(*packet1));
 		packet_id2 = nc_packet->packet_id;
 	}
 	/* Instead of zero padding the smallest data buffer, we
 	 * code into the largest.
 	 */
 	if (skb->len <= nc_packet->skb->len) {
 		skb_dest = nc_packet->skb;
 		skb_src = skb;
 	} else {
 		skb_dest = skb;
 		skb_src = nc_packet->skb;
 	}
 	/* coding_len is used when decoding the packet shorter packet */
 	coding_len = skb_src->len - unicast_size;
 	if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0)
 		goto out;
 	skb_push(skb_dest, header_add);
 	coded_packet = (struct batadv_coded_packet *)skb_dest->data;
 	skb_reset_mac_header(skb_dest);
 	coded_packet->packet_type = BATADV_CODED;
 	coded_packet->version = BATADV_COMPAT_VERSION;
 	coded_packet->ttl = packet1->ttl;
 	/* Info about first unicast packet */
 	ether_addr_copy(coded_packet->first_source, first_source);
 	ether_addr_copy(coded_packet->first_orig_dest, packet1->dest);
 	coded_packet->first_crc = packet_id1;
 	coded_packet->first_ttvn = packet1->ttvn;
 	/* Info about second unicast packet */
 	ether_addr_copy(coded_packet->second_dest, second_dest);
 	ether_addr_copy(coded_packet->second_source, second_source);
 	ether_addr_copy(coded_packet->second_orig_dest, packet2->dest);
 	coded_packet->second_crc = packet_id2;
 	coded_packet->second_ttl = packet2->ttl;
 	coded_packet->second_ttvn = packet2->ttvn;
 	coded_packet->coded_len = htons(coding_len);
 	/* This is where the magic happens: Code skb_src into skb_dest */
 	batadv_nc_memxor(skb_dest->data + coded_size,
 			 skb_src->data + unicast_size, coding_len);
 	/* Update counters accordingly */
 	if (BATADV_SKB_CB(skb_src)->decoded &&
 	    BATADV_SKB_CB(skb_dest)->decoded) {
 		/* Both packets are recoded */
 		count = skb_src->len + ETH_HLEN;
 		count += skb_dest->len + ETH_HLEN;
 		batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2);
 		batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count);
 	} else if (!BATADV_SKB_CB(skb_src)->decoded &&
 		   !BATADV_SKB_CB(skb_dest)->decoded) {
 		/* Both packets are newly coded */
 		count = skb_src->len + ETH_HLEN;
 		count += skb_dest->len + ETH_HLEN;
 		batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2);
 		batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count);
 	} else if (BATADV_SKB_CB(skb_src)->decoded &&
 		   !BATADV_SKB_CB(skb_dest)->decoded) {
 		/* skb_src recoded and skb_dest is newly coded */
 		batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
 		batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
 				   skb_src->len + ETH_HLEN);
 		batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
 		batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
 				   skb_dest->len + ETH_HLEN);
 	} else if (!BATADV_SKB_CB(skb_src)->decoded &&
 		   BATADV_SKB_CB(skb_dest)->decoded) {
 		/* skb_src is newly coded and skb_dest is recoded */
 		batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
 		batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
 				   skb_src->len + ETH_HLEN);
 		batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
 		batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
 				   skb_dest->len + ETH_HLEN);
 	}
 	/* skb_src is now coded into skb_dest, so free it */
 	kfree_skb(skb_src);
 	/* avoid duplicate free of skb from nc_packet */
 	nc_packet->skb = NULL;
 	batadv_nc_packet_free(nc_packet);
 	/* Send the coded packet and return true */
 	batadv_send_skb_packet(skb_dest, neigh_node->if_incoming, first_dest);
 	res = true;
 out:
 	if (router_neigh)
 		batadv_neigh_node_free_ref(router_neigh);
 	if (router_coding)
 		batadv_neigh_node_free_ref(router_coding);
 	if (router_neigh_ifinfo)
 		batadv_neigh_ifinfo_free_ref(router_neigh_ifinfo);
 	if (router_coding_ifinfo)
 		batadv_neigh_ifinfo_free_ref(router_coding_ifinfo);
 	return res;
 }
 /**
  * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst.
  * @skb: data skb to forward
  * @dst: destination mac address of the other skb to code with
  * @src: source mac address of skb
  *
  * Whenever we network code a packet we have to check whether we received it in
  * a network coded form. If so, we may not be able to use it for coding because
  * some neighbors may also have received (overheard) the packet in the network
  * coded form without being able to decode it. It is hard to know which of the
  * neighboring nodes was able to decode the packet, therefore we can only
  * re-code the packet if the source of the previous encoded packet is involved.
  * Since the source encoded the packet we can be certain it has all necessary
  * decode information.
  *
  * Returns true if coding of a decoded packet is allowed.
  */
 static bool batadv_nc_skb_coding_possible(struct sk_buff *skb, u8 *dst, u8 *src)
 {
 	if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src))
 		return false;
 	return true;
 }
 /**
  * batadv_nc_path_search - Find the coding path matching in_nc_node and
  *  out_nc_node to retrieve a buffered packet that can be used for coding.
  * @bat_priv: the bat priv with all the soft interface information
  * @in_nc_node: pointer to skb next hop's neighbor nc node
  * @out_nc_node: pointer to skb source's neighbor nc node
  * @skb: data skb to forward
  * @eth_dst: next hop mac address of skb
  *
  * Returns true if coding of a decoded skb is allowed.
  */
 static struct batadv_nc_packet *
 batadv_nc_path_search(struct batadv_priv *bat_priv,
 		      struct batadv_nc_node *in_nc_node,
 		      struct batadv_nc_node *out_nc_node,
 		      struct sk_buff *skb,
 		      u8 *eth_dst)
 {
 	struct batadv_nc_path *nc_path, nc_path_key;
 	struct batadv_nc_packet *nc_packet_out = NULL;
 	struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
 	struct batadv_hashtable *hash = bat_priv->nc.coding_hash;
 	int idx;
 	if (!hash)
 		return NULL;
 	/* Create almost path key */
 	batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr,
 			       out_nc_node->addr);
 	idx = batadv_nc_hash_choose(&nc_path_key, hash->size);
 	/* Check for coding opportunities in this nc_path */
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) {
 		if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr))
 			continue;
 		if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr))
 			continue;
 		spin_lock_bh(&nc_path->packet_list_lock);
 		if (list_empty(&nc_path->packet_list)) {
 			spin_unlock_bh(&nc_path->packet_list_lock);
 			continue;
 		}
 		list_for_each_entry_safe(nc_packet, nc_packet_tmp,
 					 &nc_path->packet_list, list) {
 			if (!batadv_nc_skb_coding_possible(nc_packet->skb,
 							   eth_dst,
 							   in_nc_node->addr))
 				continue;
 			/* Coding opportunity is found! */
 			list_del(&nc_packet->list);
 			nc_packet_out = nc_packet;
 			break;
 		}
 		spin_unlock_bh(&nc_path->packet_list_lock);
 		break;
 	}
 	rcu_read_unlock();
 	return nc_packet_out;
 }
 /**
  * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the
  *  skb's sender (may be equal to the originator).
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: data skb to forward
  * @eth_dst: next hop mac address of skb
  * @eth_src: source mac address of skb
  * @in_nc_node: pointer to skb next hop's neighbor nc node
  *
  * Returns an nc packet if a suitable coding packet was found, NULL otherwise.
  */
 static struct batadv_nc_packet *
 batadv_nc_skb_src_search(struct batadv_priv *bat_priv,
 			 struct sk_buff *skb,
 			 u8 *eth_dst,
 			 u8 *eth_src,
 			 struct batadv_nc_node *in_nc_node)
 {
 	struct batadv_orig_node *orig_node;
 	struct batadv_nc_node *out_nc_node;
 	struct batadv_nc_packet *nc_packet = NULL;
 	orig_node = batadv_orig_hash_find(bat_priv, eth_src);
 	if (!orig_node)
 		return NULL;
 	rcu_read_lock();
 	list_for_each_entry_rcu(out_nc_node,
 				&orig_node->out_coding_list, list) {
 		/* Check if the skb is decoded and if recoding is possible */
 		if (!batadv_nc_skb_coding_possible(skb,
 						   out_nc_node->addr, eth_src))
 			continue;
 		/* Search for an opportunity in this nc_path */
 		nc_packet = batadv_nc_path_search(bat_priv, in_nc_node,
 						  out_nc_node, skb, eth_dst);
 		if (nc_packet)
 			break;
 	}
 	rcu_read_unlock();
 	batadv_orig_node_free_ref(orig_node);
 	return nc_packet;
 }
 /**
  * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the
  *  unicast skb before it is stored for use in later decoding
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: data skb to store
  * @eth_dst_new: new destination mac address of skb
  */
 static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv,
 					      struct sk_buff *skb,
 					      u8 *eth_dst_new)
 {
 	struct ethhdr *ethhdr;
 	/* Copy skb header to change the mac header */
 	skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
 	if (!skb)
 		return;
 	/* Set the mac header as if we actually sent the packet uncoded */
 	ethhdr = eth_hdr(skb);
 	ether_addr_copy(ethhdr->h_source, ethhdr->h_dest);
 	ether_addr_copy(ethhdr->h_dest, eth_dst_new);
 	/* Set data pointer to MAC header to mimic packets from our tx path */
 	skb_push(skb, ETH_HLEN);
 	/* Add the packet to the decoding packet pool */
 	batadv_nc_skb_store_for_decoding(bat_priv, skb);
 	/* batadv_nc_skb_store_for_decoding() clones the skb, so we must free
 	 * our ref
 	 */
 	kfree_skb(skb);
 }
 /**
  * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst.
  * @skb: data skb to forward
  * @neigh_node: next hop to forward packet to
  * @ethhdr: pointer to the ethernet header inside the skb
  *
  * Loops through list of neighboring nodes the next hop has a good connection to
  * (receives OGMs with a sufficient quality). We need to find a neighbor of our
  * next hop that potentially sent a packet which our next hop also received
  * (overheard) and has stored for later decoding.
  *
  * Returns true if the skb was consumed (encoded packet sent) or false otherwise
  */
 static bool batadv_nc_skb_dst_search(struct sk_buff *skb,
 				     struct batadv_neigh_node *neigh_node,
 				     struct ethhdr *ethhdr)
 {
 	struct net_device *netdev = neigh_node->if_incoming->soft_iface;
 	struct batadv_priv *bat_priv = netdev_priv(netdev);
 	struct batadv_orig_node *orig_node = neigh_node->orig_node;
 	struct batadv_nc_node *nc_node;
 	struct batadv_nc_packet *nc_packet = NULL;
 	rcu_read_lock();
 	list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) {
 		/* Search for coding opportunity with this in_nc_node */
 		nc_packet = batadv_nc_skb_src_search(bat_priv, skb,
 						     neigh_node->addr,
 						     ethhdr->h_source, nc_node);
 		/* Opportunity was found, so stop searching */
 		if (nc_packet)
 			break;
 	}
 	rcu_read_unlock();
 	if (!nc_packet)
 		return false;
 	/* Save packets for later decoding */
 	batadv_nc_skb_store_before_coding(bat_priv, skb,
 					  neigh_node->addr);
 	batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb,
 					  nc_packet->neigh_node->addr);
 	/* Code and send packets */
 	if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet,
 				   neigh_node))
 		return true;
 	/* out of mem ? Coding failed - we have to free the buffered packet
 	 * to avoid memleaks. The skb passed as argument will be dealt with
 	 * by the calling function.
 	 */
 	batadv_nc_send_packet(nc_packet);
 	return false;
 }
 /**
  * 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
  *
  * 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)
 {
 	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;
 	struct ethhdr *ethhdr = eth_hdr(skb);
 	__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->packet_type != BATADV_UNICAST)
 		goto out;
 	/* Try to find a coding opportunity and send the skb if one is found */
 	if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr))
 		return true;
 	/* 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_skb_store_for_decoding - save a clone of the skb which can be used
  *  when decoding coded packets
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: data skb to store
  */
 void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv,
 				      struct sk_buff *skb)
 {
 	struct batadv_unicast_packet *packet;
 	struct batadv_nc_path *nc_path;
 	struct ethhdr *ethhdr = eth_hdr(skb);
 	__be32 packet_id;
 	u8 *payload;
 	/* Check if network coding is enabled */
 	if (!atomic_read(&bat_priv->network_coding))
 		goto out;
 	/* Check for supported packet type */
 	payload = skb_network_header(skb);
 	packet = (struct batadv_unicast_packet *)payload;
 	if (packet->packet_type != BATADV_UNICAST)
 		goto out;
 	/* Find existing nc_path or create a new */
 	nc_path = batadv_nc_get_path(bat_priv,
 				     bat_priv->nc.decoding_hash,
 				     ethhdr->h_source,
 				     ethhdr->h_dest);
 	if (!nc_path)
 		goto out;
 	/* Clone skb and adjust skb->data to point at batman header */
 	skb = skb_clone(skb, GFP_ATOMIC);
 	if (unlikely(!skb))
 		goto free_nc_path;
 	if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
 		goto free_skb;
 	if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN)))
 		goto free_skb;
 	/* Add skb to nc_path */
 	packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
 	if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id))
 		goto free_skb;
 	batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER);
 	return;
 free_skb:
 	kfree_skb(skb);
 free_nc_path:
 	batadv_nc_path_free_ref(nc_path);
 out:
 	return;
 }
 /**
  * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet
  *  should be saved in the decoding buffer and, if so, store it there
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: unicast skb to store
  */
 void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv,
 					 struct sk_buff *skb)
 {
 	struct ethhdr *ethhdr = eth_hdr(skb);
 	if (batadv_is_my_mac(bat_priv, ethhdr->h_dest))
 		return;
 	/* Set data pointer to MAC header to mimic packets from our tx path */
 	skb_push(skb, ETH_HLEN);
 	batadv_nc_skb_store_for_decoding(bat_priv, skb);
 }
 /**
  * batadv_nc_skb_decode_packet - decode given skb using the decode data stored
  *  in nc_packet
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: unicast skb to decode
  * @nc_packet: decode data needed to decode the skb
  *
  * Returns pointer to decoded unicast packet if the packet was decoded or NULL
  * in case of an error.
  */
 static struct batadv_unicast_packet *
 batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb,
 			    struct batadv_nc_packet *nc_packet)
 {
 	const int h_size = sizeof(struct batadv_unicast_packet);
 	const int h_diff = sizeof(struct batadv_coded_packet) - h_size;
 	struct batadv_unicast_packet *unicast_packet;
 	struct batadv_coded_packet coded_packet_tmp;
 	struct ethhdr *ethhdr, ethhdr_tmp;
 	u8 *orig_dest, ttl, ttvn;
 	unsigned int coding_len;
 	int err;
 	/* Save headers temporarily */
 	memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp));
 	memcpy(&ethhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp));
 	if (skb_cow(skb, 0) < 0)
 		return NULL;
 	if (unlikely(!skb_pull_rcsum(skb, h_diff)))
 		return NULL;
 	/* Data points to batman header, so set mac header 14 bytes before
 	 * and network to data
 	 */
 	skb_set_mac_header(skb, -ETH_HLEN);
 	skb_reset_network_header(skb);
 	/* Reconstruct original mac header */
 	ethhdr = eth_hdr(skb);
 	*ethhdr = ethhdr_tmp;
 	/* Select the correct unicast header information based on the location
 	 * of our mac address in the coded_packet header
 	 */
 	if (batadv_is_my_mac(bat_priv, coded_packet_tmp.second_dest)) {
 		/* If we are the second destination the packet was overheard,
 		 * so the Ethernet address must be copied to h_dest and
 		 * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST
 		 */
 		ether_addr_copy(ethhdr->h_dest, coded_packet_tmp.second_dest);
 		skb->pkt_type = PACKET_HOST;
 		orig_dest = coded_packet_tmp.second_orig_dest;
 		ttl = coded_packet_tmp.second_ttl;
 		ttvn = coded_packet_tmp.second_ttvn;
 	} else {
 		orig_dest = coded_packet_tmp.first_orig_dest;
 		ttl = coded_packet_tmp.ttl;
 		ttvn = coded_packet_tmp.first_ttvn;
 	}
 	coding_len = ntohs(coded_packet_tmp.coded_len);
 	if (coding_len > skb->len)
 		return NULL;
 	/* Here the magic is reversed:
 	 *   extract the missing packet from the received coded packet
 	 */
 	batadv_nc_memxor(skb->data + h_size,
 			 nc_packet->skb->data + h_size,
 			 coding_len);
 	/* Resize decoded skb if decoded with larger packet */
 	if (nc_packet->skb->len > coding_len + h_size) {
 		err = pskb_trim_rcsum(skb, coding_len + h_size);
 		if (err)
 			return NULL;
 	}
 	/* Create decoded unicast packet */
 	unicast_packet = (struct batadv_unicast_packet *)skb->data;
 	unicast_packet->packet_type = BATADV_UNICAST;
 	unicast_packet->version = BATADV_COMPAT_VERSION;
 	unicast_packet->ttl = ttl;
 	ether_addr_copy(unicast_packet->dest, orig_dest);
 	unicast_packet->ttvn = ttvn;
 	batadv_nc_packet_free(nc_packet);
 	return unicast_packet;
 }
 /**
  * batadv_nc_find_decoding_packet - search through buffered decoding data to
  *  find the data needed to decode the coded packet
  * @bat_priv: the bat priv with all the soft interface information
  * @ethhdr: pointer to the ethernet header inside the coded packet
  * @coded: coded packet we try to find decode data for
  *
  * Returns pointer to nc packet if the needed data was found or NULL otherwise.
  */
 static struct batadv_nc_packet *
 batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv,
 			       struct ethhdr *ethhdr,
 			       struct batadv_coded_packet *coded)
 {
 	struct batadv_hashtable *hash = bat_priv->nc.decoding_hash;
 	struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL;
 	struct batadv_nc_path *nc_path, nc_path_key;
 	u8 *dest, *source;
 	__be32 packet_id;
 	int index;
 	if (!hash)
 		return NULL;
 	/* Select the correct packet id based on the location of our mac-addr */
 	dest = ethhdr->h_source;
 	if (!batadv_is_my_mac(bat_priv, coded->second_dest)) {
 		source = coded->second_source;
 		packet_id = coded->second_crc;
 	} else {
 		source = coded->first_source;
 		packet_id = coded->first_crc;
 	}
 	batadv_nc_hash_key_gen(&nc_path_key, source, dest);
 	index = batadv_nc_hash_choose(&nc_path_key, hash->size);
 	/* Search for matching coding path */
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) {
 		/* Find matching nc_packet */
 		spin_lock_bh(&nc_path->packet_list_lock);
 		list_for_each_entry(tmp_nc_packet,
 				    &nc_path->packet_list, list) {
 			if (packet_id == tmp_nc_packet->packet_id) {
 				list_del(&tmp_nc_packet->list);
 				nc_packet = tmp_nc_packet;
 				break;
 			}
 		}
 		spin_unlock_bh(&nc_path->packet_list_lock);
 		if (nc_packet)
 			break;
 	}
 	rcu_read_unlock();
 	if (!nc_packet)
 		batadv_dbg(BATADV_DBG_NC, bat_priv,
 			   "No decoding packet found for %u\n", packet_id);
 	return nc_packet;
 }
 /**
  * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the
  *  resulting unicast packet
  * @skb: incoming coded packet
  * @recv_if: pointer to interface this packet was received on
  */
 static int batadv_nc_recv_coded_packet(struct sk_buff *skb,
 				       struct batadv_hard_iface *recv_if)
 {
 	struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 	struct batadv_unicast_packet *unicast_packet;
 	struct batadv_coded_packet *coded_packet;
 	struct batadv_nc_packet *nc_packet;
 	struct ethhdr *ethhdr;
 	int hdr_size = sizeof(*coded_packet);
 	/* Check if network coding is enabled */
 	if (!atomic_read(&bat_priv->network_coding))
 		return NET_RX_DROP;
 	/* Make sure we can access (and remove) header */
 	if (unlikely(!pskb_may_pull(skb, hdr_size)))
 		return NET_RX_DROP;
 	coded_packet = (struct batadv_coded_packet *)skb->data;
 	ethhdr = eth_hdr(skb);
 	/* Verify frame is destined for us */
 	if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) &&
 	    !batadv_is_my_mac(bat_priv, coded_packet->second_dest))
 		return NET_RX_DROP;
 	/* Update stat counter */
 	if (batadv_is_my_mac(bat_priv, coded_packet->second_dest))
 		batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED);
 	nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr,
 						   coded_packet);
 	if (!nc_packet) {
 		batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED);
 		return NET_RX_DROP;
 	}
 	/* Make skb's linear, because decoding accesses the entire buffer */
 	if (skb_linearize(skb) < 0)
 		goto free_nc_packet;
 	if (skb_linearize(nc_packet->skb) < 0)
 		goto free_nc_packet;
 	/* Decode the packet */
 	unicast_packet = batadv_nc_skb_decode_packet(bat_priv, skb, nc_packet);
 	if (!unicast_packet) {
 		batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED);
 		goto free_nc_packet;
 	}
 	/* Mark packet as decoded to do correct recoding when forwarding */
 	BATADV_SKB_CB(skb)->decoded = true;
 	batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE);
 	batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES,
 			   skb->len + ETH_HLEN);
 	return batadv_recv_unicast_packet(skb, recv_if);
 free_nc_packet:
 	batadv_nc_packet_free(nc_packet);
 	return NET_RX_DROP;
 }
 /**
  * batadv_nc_mesh_free - clean up network coding memory
  * @bat_priv: the bat priv with all the soft interface information
  */
 void batadv_nc_mesh_free(struct batadv_priv *bat_priv)
 {
 	batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_NC, 1);
 	batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_NC, 1);
 	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);
 	batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL);
 	batadv_hash_destroy(bat_priv->nc.decoding_hash);
 }
 /**
  * batadv_nc_nodes_seq_print_text - print the nc node information
  * @seq: seq file to print on
  * @offset: not used
  */
 int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset)
 {
 	struct net_device *net_dev = (struct net_device *)seq->private;
 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
 	struct batadv_hashtable *hash = bat_priv->orig_hash;
 	struct batadv_hard_iface *primary_if;
 	struct hlist_head *head;
 	struct batadv_orig_node *orig_node;
 	struct batadv_nc_node *nc_node;
 	int i;
 	primary_if = batadv_seq_print_text_primary_if_get(seq);
 	if (!primary_if)
 		goto out;
 	/* Traverse list of originators */
 	for (i = 0; i < hash->size; i++) {
 		head = &hash->table[i];
 		/* For each orig_node in this bin */
 		rcu_read_lock();
 		hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
 			/* no need to print the orig node if it does not have
 			 * network coding neighbors
 			 */
 			if (list_empty(&orig_node->in_coding_list) &&
 			    list_empty(&orig_node->out_coding_list))
 				continue;
 			seq_printf(seq, "Node:      %pM\n", orig_node->orig);
 			seq_puts(seq, " Ingoing:  ");
 			/* For each in_nc_node to this orig_node */
 			list_for_each_entry_rcu(nc_node,
 						&orig_node->in_coding_list,
 						list)
 				seq_printf(seq, "%pM ",
 					   nc_node->addr);
 			seq_puts(seq, "\n");
 			seq_puts(seq, " Outgoing: ");
 			/* For out_nc_node to this orig_node */
 			list_for_each_entry_rcu(nc_node,
 						&orig_node->out_coding_list,
 						list)
 				seq_printf(seq, "%pM ",
 					   nc_node->addr);
 			seq_puts(seq, "\n\n");
 		}
 		rcu_read_unlock();
 	}
 out:
 	if (primary_if)
 		batadv_hardif_free_ref(primary_if);
 	return 0;
 }
 /**
  * batadv_nc_init_debugfs - create nc folder and related files in debugfs
  * @bat_priv: the bat priv with all the soft interface information
  */
 int batadv_nc_init_debugfs(struct batadv_priv *bat_priv)
 {
 	struct dentry *nc_dir, *file;
 	nc_dir = debugfs_create_dir("nc", bat_priv->debug_dir);
 	if (!nc_dir)
 		goto out;
 	file = debugfs_create_u8("min_tq", S_IRUGO | S_IWUSR, nc_dir,
 				 &bat_priv->nc.min_tq);
 	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;
 	file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir,
 				  &bat_priv->nc.max_buffer_time);
 	if (!file)
 		goto out;
 	return 0;
 out:
 	return -ENOMEM;
 }

net/batman-adv/send.c

Diff comments View file @ c799443

 /* Copyright (C) 2007-2015 B.A.T.M.A.N. contributors:
  *
  * Marek Lindner, Simon Wunderlich
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of version 2 of the GNU General Public
  * License as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 #include "send.h"
 #include "main.h"
 #include <linux/atomic.h>
 #include <linux/byteorder/generic.h>
 #include <linux/etherdevice.h>
 #include <linux/fs.h>
 #include <linux/if_ether.h>
 #include <linux/if.h>
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/netdevice.h>
 #include <linux/printk.h>
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
 #include <linux/skbuff.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/stddef.h>
 #include <linux/workqueue.h>
 #include "distributed-arp-table.h"
 #include "fragmentation.h"
 #include "gateway_client.h"
 #include "hard-interface.h"
 #include "network-coding.h"
 #include "originator.h"
 #include "routing.h"
 #include "soft-interface.h"
 #include "translation-table.h"
 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
  */
 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 ethhdr *ethhdr;
 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
 		goto send_skb_err;
 	if (unlikely(!hard_iface->net_dev))
 		goto send_skb_err;
 	if (!(hard_iface->net_dev->flags & IFF_UP)) {
 		pr_warn("Interface %s is not up - can't send packet via that interface!\n",
 			hard_iface->net_dev->name);
 		goto send_skb_err;
 	}
 	/* push to the ethernet header. */
 	if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
 		goto send_skb_err;
 	skb_reset_mac_header(skb);
 	ethhdr = eth_hdr(skb);
 	ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr);
 	ether_addr_copy(ethhdr->h_dest, dst_addr);
 	ethhdr->h_proto = htons(ETH_P_BATMAN);
 	skb_set_network_header(skb, ETH_HLEN);
 	skb->protocol = htons(ETH_P_BATMAN);
 	skb->dev = hard_iface->net_dev;
 	/* Save a clone of the skb to use when decoding coded packets */
 	batadv_nc_skb_store_for_decoding(bat_priv, skb);
 	/* dev_queue_xmit() returns a negative result on error.	 However on
 	 * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
 	 * (which is > 0). This will not be treated as an error.
 	 */
 	return dev_queue_xmit(skb);
 send_skb_err:
 	kfree_skb(skb);
 	return NET_XMIT_DROP;
 }
 /**
  * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
  * @skb: Packet to be transmitted.
  * @orig_node: Final destination of the packet.
  * @recv_if: Interface used when receiving the packet (can be NULL).
  *
  * Looks up the best next-hop towards the passed originator and passes the
  * skb on for preparation of MAC header. If the packet originated from this
  * host, NULL can be passed as recv_if and no interface alternating is
  * attempted.
  *
  * Returns NET_XMIT_SUCCESS on success, NET_XMIT_DROP on failure, or
  * NET_XMIT_POLICED if the skb is buffered for later transmit.
  */
 int batadv_send_skb_to_orig(struct sk_buff *skb,
 			    struct batadv_orig_node *orig_node,
 			    struct batadv_hard_iface *recv_if)
 {
 	struct batadv_priv *bat_priv = orig_node->bat_priv;
 	struct batadv_neigh_node *neigh_node;
 	int ret = NET_XMIT_DROP;
 	/* batadv_find_router() increases neigh_nodes refcount if found. */
 	neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 	if (!neigh_node)
 		goto out;
 	/* Check if the skb is too large to send in one piece and fragment
 	 * it if needed.
 	 */
 	if (atomic_read(&bat_priv->fragmentation) &&
 	    skb->len > neigh_node->if_incoming->net_dev->mtu) {
 		/* Fragment and send packet. */
 		if (batadv_frag_send_packet(skb, orig_node, neigh_node))
 			ret = NET_XMIT_SUCCESS;
 		goto out;
 	}
 	/* try to network code the packet, if it is received on an interface
 	 * (i.e. being forwarded). If the packet originates from this node or if
 	 * network coding fails, then send the packet as usual.
 	 */
 	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);
 		ret = NET_XMIT_SUCCESS;
 	}
 out:
 	if (neigh_node)
 		batadv_neigh_node_free_ref(neigh_node);
 	return ret;
 }
 /**
  * batadv_send_skb_push_fill_unicast - extend the buffer and initialize the
  *  common fields for unicast packets
  * @skb: the skb carrying the unicast header to initialize
  * @hdr_size: amount of bytes to push at the beginning of the skb
  * @orig_node: the destination node
  *
  * Returns false if the buffer extension was not possible or true otherwise.
  */
 static bool
 batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
 				  struct batadv_orig_node *orig_node)
 {
 	struct batadv_unicast_packet *unicast_packet;
 	u8 ttvn = (u8)atomic_read(&orig_node->last_ttvn);
 	if (batadv_skb_head_push(skb, hdr_size) < 0)
 		return false;
 	unicast_packet = (struct batadv_unicast_packet *)skb->data;
 	unicast_packet->version = BATADV_COMPAT_VERSION;
 	/* batman packet type: unicast */
 	unicast_packet->packet_type = BATADV_UNICAST;
 	/* set unicast ttl */
 	unicast_packet->ttl = BATADV_TTL;
 	/* copy the destination for faster routing */
 	ether_addr_copy(unicast_packet->dest, orig_node->orig);
 	/* set the destination tt version number */
 	unicast_packet->ttvn = ttvn;
 	return true;
 }
 /**
  * batadv_send_skb_prepare_unicast - encapsulate an skb with a unicast header
  * @skb: the skb containing the payload to encapsulate
  * @orig_node: the destination node
  *
  * Returns false if the payload could not be encapsulated or true otherwise.
  */
 static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
 					    struct batadv_orig_node *orig_node)
 {
 	size_t uni_size = sizeof(struct batadv_unicast_packet);
 	return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
 }
 /**
  * batadv_send_skb_prepare_unicast_4addr - encapsulate an skb with a
  *  unicast 4addr header
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: the skb containing the payload to encapsulate
  * @orig_node: the destination node
  * @packet_subtype: the unicast 4addr packet subtype to use
  *
  * Returns false if the payload could not be encapsulated or true otherwise.
  */
 bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
 					   struct sk_buff *skb,
 					   struct batadv_orig_node *orig,
 					   int packet_subtype)
 {
 	struct batadv_hard_iface *primary_if;
 	struct batadv_unicast_4addr_packet *uc_4addr_packet;
 	bool ret = false;
 	primary_if = batadv_primary_if_get_selected(bat_priv);
 	if (!primary_if)
 		goto out;
 	/* Pull the header space and fill the unicast_packet substructure.
 	 * We can do that because the first member of the uc_4addr_packet
 	 * is of type struct unicast_packet
 	 */
 	if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
 					       orig))
 		goto out;
 	uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
 	uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
 	ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr);
 	uc_4addr_packet->subtype = packet_subtype;
 	uc_4addr_packet->reserved = 0;
 	ret = true;
 out:
 	if (primary_if)
 		batadv_hardif_free_ref(primary_if);
 	return ret;
 }
 /**
  * batadv_send_skb_unicast - encapsulate and send an skb via unicast
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: payload to send
  * @packet_type: the batman unicast packet type to use
  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
  *  4addr packets)
  * @orig_node: the originator to send the packet to
  * @vid: the vid to be used to search the translation table
  *
  * Wrap the given skb into a batman-adv unicast or unicast-4addr header
  * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
  * as packet_type. Then send this frame to the given orig_node and release a
  * reference to this orig_node.
  *
  * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
  */
 int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
 			    struct sk_buff *skb, int packet_type,
 			    int packet_subtype,
 			    struct batadv_orig_node *orig_node,
 			    unsigned short vid)
 {
 	struct batadv_unicast_packet *unicast_packet;
 	struct ethhdr *ethhdr;
 	int ret = NET_XMIT_DROP;
 	if (!orig_node)
 		goto out;
 	switch (packet_type) {
 	case BATADV_UNICAST:
 		if (!batadv_send_skb_prepare_unicast(skb, orig_node))
 			goto out;
 		break;
 	case BATADV_UNICAST_4ADDR:
 		if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
 							   orig_node,
 							   packet_subtype))
 			goto out;
 		break;
 	default:
 		/* this function supports UNICAST and UNICAST_4ADDR only. It
 		 * should never be invoked with any other packet type
 		 */
 		goto out;
 	}
 	/* skb->data might have been reallocated by
 	 * batadv_send_skb_prepare_unicast{,_4addr}()
 	 */
 	ethhdr = eth_hdr(skb);
 	unicast_packet = (struct batadv_unicast_packet *)skb->data;
 	/* inform the destination node that we are still missing a correct route
 	 * for this client. The destination will receive this packet and will
 	 * try to reroute it because the ttvn contained in the header is less
 	 * than the current one
 	 */
 	if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
 		unicast_packet->ttvn = unicast_packet->ttvn - 1;
 	if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
 		ret = NET_XMIT_SUCCESS;
 out:
 	if (orig_node)
 		batadv_orig_node_free_ref(orig_node);
 	if (ret == NET_XMIT_DROP)
 		kfree_skb(skb);
 	return ret;
 }
 /**
  * batadv_send_skb_via_tt_generic - send an skb via TT lookup
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: payload to send
  * @packet_type: the batman unicast packet type to use
  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
  *  4addr packets)
  * @dst_hint: can be used to override the destination contained in the skb
  * @vid: the vid to be used to search the translation table
  *
  * Look up the recipient node for the destination address in the ethernet
  * header via the translation table. Wrap the given skb into a batman-adv
  * unicast or unicast-4addr header depending on whether BATADV_UNICAST or
  * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
  * to the according destination node.
  *
  * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
  */
 int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
 				   struct sk_buff *skb, int packet_type,
 				   int packet_subtype, u8 *dst_hint,
 				   unsigned short vid)
 {
 	struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
 	struct batadv_orig_node *orig_node;
 	u8 *src, *dst;
 	src = ethhdr->h_source;
 	dst = ethhdr->h_dest;
 	/* if we got an hint! let's send the packet to this client (if any) */
 	if (dst_hint) {
 		src = NULL;
 		dst = dst_hint;
 	}
 	orig_node = batadv_transtable_search(bat_priv, src, dst, vid);
 	return batadv_send_skb_unicast(bat_priv, skb, packet_type,
 				       packet_subtype, orig_node, vid);
 }
 /**
  * batadv_send_skb_via_gw - send an skb via gateway lookup
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: payload to send
  * @vid: the vid to be used to search the translation table
  *
  * Look up the currently selected gateway. Wrap the given skb into a batman-adv
  * unicast header and send this frame to this gateway node.
  *
  * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
  */
 int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
 			   unsigned short vid)
 {
 	struct batadv_orig_node *orig_node;
 	orig_node = batadv_gw_get_selected_orig(bat_priv);
 	return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
 				       orig_node, vid);
 }
 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
 {
 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 	if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
 	    (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
 		return;
 	/* the interface gets activated here to avoid race conditions between
 	 * the moment of activating the interface in
 	 * hardif_activate_interface() where the originator mac is set and
 	 * outdated packets (especially uninitialized mac addresses) in the
 	 * packet queue
 	 */
 	if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
 		hard_iface->if_status = BATADV_IF_ACTIVE;
 	bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
 }
 static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
 {
-	if (forw_packet->skb)
+	kfree_skb(forw_packet->skb);
-		kfree_skb(forw_packet->skb);
 	if (forw_packet->if_incoming)
 		batadv_hardif_free_ref(forw_packet->if_incoming);
 	if (forw_packet->if_outgoing)
 		batadv_hardif_free_ref(forw_packet->if_outgoing);
 	kfree(forw_packet);
 }
 static void
 _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 				 struct batadv_forw_packet *forw_packet,
 				 unsigned long send_time)
 {
 	/* add new packet to packet list */
 	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 	hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 	/* start timer for this packet */
 	queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
 			   send_time);
 }
 /* add a broadcast packet to the queue and setup timers. broadcast packets
  * are sent multiple times to increase probability for being received.
  *
  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
  * errors.
  *
  * The skb is not consumed, so the caller should make sure that the
  * skb is freed.
  */
 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 				    const struct sk_buff *skb,
 				    unsigned long delay)
 {
 	struct batadv_hard_iface *primary_if = NULL;
 	struct batadv_forw_packet *forw_packet;
 	struct batadv_bcast_packet *bcast_packet;
 	struct sk_buff *newskb;
 	if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 			   "bcast packet queue full\n");
 		goto out;
 	}
 	primary_if = batadv_primary_if_get_selected(bat_priv);
 	if (!primary_if)
 		goto out_and_inc;
 	forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 	if (!forw_packet)
 		goto out_and_inc;
 	newskb = skb_copy(skb, GFP_ATOMIC);
 	if (!newskb)
 		goto packet_free;
 	/* as we have a copy now, it is safe to decrease the TTL */
 	bcast_packet = (struct batadv_bcast_packet *)newskb->data;
 	bcast_packet->ttl--;
 	skb_reset_mac_header(newskb);
 	forw_packet->skb = newskb;
 	forw_packet->if_incoming = primary_if;
 	forw_packet->if_outgoing = NULL;
 	/* how often did we send the bcast packet ? */
 	forw_packet->num_packets = 0;
 	INIT_DELAYED_WORK(&forw_packet->delayed_work,
 			  batadv_send_outstanding_bcast_packet);
 	_batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
 	return NETDEV_TX_OK;
 packet_free:
 	kfree(forw_packet);
 out_and_inc:
 	atomic_inc(&bat_priv->bcast_queue_left);
 out:
 	if (primary_if)
 		batadv_hardif_free_ref(primary_if);
 	return NETDEV_TX_BUSY;
 }
 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 {
 	struct batadv_hard_iface *hard_iface;
 	struct delayed_work *delayed_work;
 	struct batadv_forw_packet *forw_packet;
 	struct sk_buff *skb1;
 	struct net_device *soft_iface;
 	struct batadv_priv *bat_priv;
 	delayed_work = container_of(work, struct delayed_work, work);
 	forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 				   delayed_work);
 	soft_iface = forw_packet->if_incoming->soft_iface;
 	bat_priv = netdev_priv(soft_iface);
 	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 	hlist_del(&forw_packet->list);
 	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 		goto out;
 	if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet))
 		goto out;
 	/* rebroadcast packet */
 	rcu_read_lock();
 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 		if (hard_iface->soft_iface != soft_iface)
 			continue;
 		if (forw_packet->num_packets >= hard_iface->num_bcasts)
 			continue;
 		/* 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);
 	}
 	rcu_read_unlock();
 	forw_packet->num_packets++;
 	/* if we still have some more bcasts to send */
 	if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) {
 		_batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
 						 msecs_to_jiffies(5));
 		return;
 	}
 out:
 	batadv_forw_packet_free(forw_packet);
 	atomic_inc(&bat_priv->bcast_queue_left);
 }
 void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
 {
 	struct delayed_work *delayed_work;
 	struct batadv_forw_packet *forw_packet;
 	struct batadv_priv *bat_priv;
 	delayed_work = container_of(work, struct delayed_work, work);
 	forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 				   delayed_work);
 	bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 	spin_lock_bh(&bat_priv->forw_bat_list_lock);
 	hlist_del(&forw_packet->list);
 	spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 		goto out;
 	bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
 	/* we have to have at least one packet in the queue to determine the
 	 * queues wake up time unless we are shutting down.
 	 *
 	 * only re-schedule if this is the "original" copy, e.g. the OGM of the
 	 * primary interface should only be rescheduled once per period, but
 	 * this function will be called for the forw_packet instances of the
 	 * other secondary interfaces as well.
 	 */
 	if (forw_packet->own &&
 	    forw_packet->if_incoming == forw_packet->if_outgoing)
 		batadv_schedule_bat_ogm(forw_packet->if_incoming);
 out:
 	/* don't count own packet */
 	if (!forw_packet->own)
 		atomic_inc(&bat_priv->batman_queue_left);
 	batadv_forw_packet_free(forw_packet);
 }
 void
 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
 				 const struct batadv_hard_iface *hard_iface)
 {
 	struct batadv_forw_packet *forw_packet;
 	struct hlist_node *safe_tmp_node;
 	bool pending;
 	if (hard_iface)
 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 			   "purge_outstanding_packets(): %s\n",
 			   hard_iface->net_dev->name);
 	else
 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 			   "purge_outstanding_packets()\n");
 	/* free bcast list */
 	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 	hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 				  &bat_priv->forw_bcast_list, list) {
 		/* if purge_outstanding_packets() was called with an argument
 		 * we delete only packets belonging to the given interface
 		 */
 		if ((hard_iface) &&
 		    (forw_packet->if_incoming != hard_iface) &&
 		    (forw_packet->if_outgoing != hard_iface))
 			continue;
 		spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 		/* batadv_send_outstanding_bcast_packet() will lock the list to
 		 * delete the item from the list
 		 */
 		pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 		spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 		if (pending) {
 			hlist_del(&forw_packet->list);
 			batadv_forw_packet_free(forw_packet);
 		}
 	}
 	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 	/* free batman packet list */
 	spin_lock_bh(&bat_priv->forw_bat_list_lock);
 	hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 				  &bat_priv->forw_bat_list, list) {
 		/* if purge_outstanding_packets() was called with an argument
 		 * we delete only packets belonging to the given interface
 		 */
 		if ((hard_iface) &&
 		    (forw_packet->if_incoming != hard_iface) &&
 		    (forw_packet->if_outgoing != hard_iface))
 			continue;
 		spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 		/* send_outstanding_bat_packet() will lock the list to
 		 * delete the item from the list
 		 */
 		pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 		spin_lock_bh(&bat_priv->forw_bat_list_lock);
 		if (pending) {
 			hlist_del(&forw_packet->list);
 			batadv_forw_packet_free(forw_packet);
 		}
 	}
 	spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 }

1	/* Copyright (C) 2007-2015 B.A.T.M.A.N. contributors:	1	/* Copyright (C) 2007-2015 B.A.T.M.A.N. contributors:
2	*	2	*
3	* Marek Lindner, Simon Wunderlich	3	* Marek Lindner, Simon Wunderlich
4	*	4	*
5	* This program is free software; you can redistribute it and/or	5	* This program is free software; you can redistribute it and/or
6	* modify it under the terms of version 2 of the GNU General Public	6	* modify it under the terms of version 2 of the GNU General Public
7	* License as published by the Free Software Foundation.	7	* License as published by the Free Software Foundation.
8	*	8	*
9	* This program is distributed in the hope that it will be useful, but	9	* This program is distributed in the hope that it will be useful, but
10	* WITHOUT ANY WARRANTY; without even the implied warranty of	10	* WITHOUT ANY WARRANTY; without even the implied warranty of
11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12	* General Public License for more details.	12	* General Public License for more details.
13	*	13	*
14	* You should have received a copy of the GNU General Public License	14	* You should have received a copy of the GNU General Public License
15	* along with this program; if not, see <http://www.gnu.org/licenses/>.	15	* along with this program; if not, see <http://www.gnu.org/licenses/>.
16	*/	16	*/
17		17
18	#include "main.h"	18	#include "main.h"
19		19
20	#include <linux/atomic.h>	20	#include <linux/atomic.h>
21	#include <linux/bug.h>	21	#include <linux/bug.h>
22	#include <linux/byteorder/generic.h>	22	#include <linux/byteorder/generic.h>
23	#include <linux/crc32c.h>	23	#include <linux/crc32c.h>
24	#include <linux/errno.h>	24	#include <linux/errno.h>
25	#include <linux/fs.h>	25	#include <linux/fs.h>
26	#include <linux/if_ether.h>	26	#include <linux/if_ether.h>
27	#include <linux/if_vlan.h>	27	#include <linux/if_vlan.h>
28	#include <linux/init.h>	28	#include <linux/init.h>
29	#include <linux/ip.h>	29	#include <linux/ip.h>
30	#include <linux/ipv6.h>	30	#include <linux/ipv6.h>
31	#include <linux/kernel.h>	31	#include <linux/kernel.h>
32	#include <linux/list.h>	32	#include <linux/list.h>
33	#include <linux/lockdep.h>	33	#include <linux/lockdep.h>
34	#include <linux/module.h>	34	#include <linux/module.h>
35	#include <linux/moduleparam.h>	35	#include <linux/moduleparam.h>
36	#include <linux/netdevice.h>	36	#include <linux/netdevice.h>
37	#include <linux/pkt_sched.h>	37	#include <linux/pkt_sched.h>
38	#include <linux/rculist.h>	38	#include <linux/rculist.h>
39	#include <linux/rcupdate.h>	39	#include <linux/rcupdate.h>
40	#include <linux/seq_file.h>	40	#include <linux/seq_file.h>