#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);
/**
*/
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;
}
/**
{
atomic_set(&bat_priv->network_coding, 1);
bat_priv->nc.min_tq = 200;
+ bat_priv->nc.max_fwd_delay = 10;
}
/**
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);
+
+ 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
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_purge_orig_nc_nodes - go through list of nc nodes and purge stale
* entries
}
}
+/**
+ * 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 */
+ 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_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 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 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_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_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
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);
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,
+ 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);
}
/**
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:
projects / openwrt / staging / blogic.git / commitdiff