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authorAntonio Quartulli <ordex@autistici.org>2012-06-30 22:01:19 +0400
committerAntonio Quartulli <ordex@autistici.org>2012-11-07 23:00:20 +0400
commit2f1dfbe185075a50dc8f0490a136377af53a1c62 (patch)
tree45ade201ca4b63e4409fc21567db0f750abc8bc7 /net/batman-adv/distributed-arp-table.c
parent785ea1144182c341b8b85b0f8180291839d176a8 (diff)
downloadlinux-2f1dfbe185075a50dc8f0490a136377af53a1c62.tar.xz
batman-adv: Distributed ARP Table - implement local storage
Since batman-adv cannot inter-operate with the host ARP table, this patch introduces a batman-adv private storage for ARP entries exchanged within DAT. This storage will represent the node local cache in the DAT protocol. Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Diffstat (limited to 'net/batman-adv/distributed-arp-table.c')
-rw-r--r--net/batman-adv/distributed-arp-table.c296
1 files changed, 296 insertions, 0 deletions
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index ce39e8a5be38..2ef90e3ea2c4 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -28,6 +28,119 @@
#include "types.h"
#include "unicast.h"
+static void batadv_dat_purge(struct work_struct *work);
+
+/**
+ * batadv_dat_start_timer - initialise the DAT periodic worker
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
+{
+ INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
+ queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
+ msecs_to_jiffies(10000));
+}
+
+/**
+ * batadv_dat_entry_free_ref - decrements the dat_entry refcounter and possibly
+ * free it
+ * @dat_entry: the oentry to free
+ */
+static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry)
+{
+ if (atomic_dec_and_test(&dat_entry->refcount))
+ kfree_rcu(dat_entry, rcu);
+}
+
+/**
+ * batadv_dat_to_purge - checks whether a dat_entry has to be purged or not
+ * @dat_entry: the entry to check
+ *
+ * Returns true if the entry has to be purged now, false otherwise
+ */
+static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
+{
+ return batadv_has_timed_out(dat_entry->last_update,
+ BATADV_DAT_ENTRY_TIMEOUT);
+}
+
+/**
+ * __batadv_dat_purge - delete entries from the DAT local storage
+ * @bat_priv: the bat priv with all the soft interface information
+ * @to_purge: function in charge to decide whether an entry has to be purged or
+ * not. This function takes the dat_entry as argument and has to
+ * returns a boolean value: true is the entry has to be deleted,
+ * false otherwise
+ *
+ * Loops over each entry in the DAT local storage and delete it if and only if
+ * the to_purge function passed as argument returns true
+ */
+static void __batadv_dat_purge(struct batadv_priv *bat_priv,
+ bool (*to_purge)(struct batadv_dat_entry *))
+{
+ spinlock_t *list_lock; /* protects write access to the hash lists */
+ struct batadv_dat_entry *dat_entry;
+ struct hlist_node *node, *node_tmp;
+ struct hlist_head *head;
+ uint32_t i;
+
+ if (!bat_priv->dat.hash)
+ return;
+
+ for (i = 0; i < bat_priv->dat.hash->size; i++) {
+ head = &bat_priv->dat.hash->table[i];
+ list_lock = &bat_priv->dat.hash->list_locks[i];
+
+ spin_lock_bh(list_lock);
+ hlist_for_each_entry_safe(dat_entry, node, node_tmp, head,
+ hash_entry) {
+ /* if an helper function has been passed as parameter,
+ * ask it if the entry has to be purged or not
+ */
+ if (to_purge && !to_purge(dat_entry))
+ continue;
+
+ hlist_del_rcu(node);
+ batadv_dat_entry_free_ref(dat_entry);
+ }
+ spin_unlock_bh(list_lock);
+ }
+}
+
+/**
+ * batadv_dat_purge - periodic task that deletes old entries from the local DAT
+ * hash table
+ * @work: kernel work struct
+ */
+static void batadv_dat_purge(struct work_struct *work)
+{
+ struct delayed_work *delayed_work;
+ struct batadv_priv_dat *priv_dat;
+ struct batadv_priv *bat_priv;
+
+ delayed_work = container_of(work, struct delayed_work, work);
+ priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
+ bat_priv = container_of(priv_dat, struct batadv_priv, dat);
+
+ __batadv_dat_purge(bat_priv, batadv_dat_to_purge);
+ batadv_dat_start_timer(bat_priv);
+}
+
+/**
+ * batadv_compare_dat - comparing function used in the local DAT hash table
+ * @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_compare_dat(const struct hlist_node *node, const void *data2)
+{
+ const void *data1 = container_of(node, struct batadv_dat_entry,
+ hash_entry);
+
+ return (memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0);
+}
+
/**
* batadv_hash_dat - compute the hash value for an IP address
* @data: data to hash
@@ -55,6 +168,96 @@ static uint32_t batadv_hash_dat(const void *data, uint32_t size)
}
/**
+ * batadv_dat_entry_hash_find - looks for a given dat_entry in the local hash
+ * table
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ip: search key
+ *
+ * Returns the dat_entry if found, NULL otherwise
+ */
+static struct batadv_dat_entry *
+batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip)
+{
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct batadv_dat_entry *dat_entry, *dat_entry_tmp = NULL;
+ struct batadv_hashtable *hash = bat_priv->dat.hash;
+ uint32_t index;
+
+ if (!hash)
+ return NULL;
+
+ index = batadv_hash_dat(&ip, hash->size);
+ head = &hash->table[index];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(dat_entry, node, head, hash_entry) {
+ if (dat_entry->ip != ip)
+ continue;
+
+ if (!atomic_inc_not_zero(&dat_entry->refcount))
+ continue;
+
+ dat_entry_tmp = dat_entry;
+ break;
+ }
+ rcu_read_unlock();
+
+ return dat_entry_tmp;
+}
+
+/**
+ * batadv_dat_entry_add - add a new dat entry or update it if already exists
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ip: ipv4 to add/edit
+ * @mac_addr: mac address to assign to the given ipv4
+ */
+static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
+ uint8_t *mac_addr)
+{
+ struct batadv_dat_entry *dat_entry;
+ int hash_added;
+
+ dat_entry = batadv_dat_entry_hash_find(bat_priv, ip);
+ /* if this entry is already known, just update it */
+ if (dat_entry) {
+ if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
+ memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
+ dat_entry->last_update = jiffies;
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "Entry updated: %pI4 %pM\n", &dat_entry->ip,
+ dat_entry->mac_addr);
+ goto out;
+ }
+
+ dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
+ if (!dat_entry)
+ goto out;
+
+ dat_entry->ip = ip;
+ memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
+ dat_entry->last_update = jiffies;
+ atomic_set(&dat_entry->refcount, 2);
+
+ hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
+ batadv_hash_dat, &dat_entry->ip,
+ &dat_entry->hash_entry);
+
+ if (unlikely(hash_added != 0)) {
+ /* remove the reference for the hash */
+ batadv_dat_entry_free_ref(dat_entry);
+ goto out;
+ }
+
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM\n",
+ &dat_entry->ip, dat_entry->mac_addr);
+
+out:
+ if (dat_entry)
+ batadv_dat_entry_free_ref(dat_entry);
+}
+
+/**
* batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
* @res: the array with the already selected candidates
* @select: number of already selected candidates
@@ -268,3 +471,96 @@ out:
kfree(cand);
return ret;
}
+
+/**
+ * batadv_dat_hash_free - free the local DAT hash table
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
+{
+ __batadv_dat_purge(bat_priv, NULL);
+
+ batadv_hash_destroy(bat_priv->dat.hash);
+
+ bat_priv->dat.hash = NULL;
+}
+
+/**
+ * batadv_dat_init - initialise the DAT internals
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+int batadv_dat_init(struct batadv_priv *bat_priv)
+{
+ if (bat_priv->dat.hash)
+ return 0;
+
+ bat_priv->dat.hash = batadv_hash_new(1024);
+
+ if (!bat_priv->dat.hash)
+ return -ENOMEM;
+
+ batadv_dat_start_timer(bat_priv);
+
+ return 0;
+}
+
+/**
+ * batadv_dat_free - free the DAT internals
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+void batadv_dat_free(struct batadv_priv *bat_priv)
+{
+ cancel_delayed_work_sync(&bat_priv->dat.work);
+
+ batadv_dat_hash_free(bat_priv);
+}
+
+/**
+ * batadv_dat_cache_seq_print_text - print the local DAT hash table
+ * @seq: seq file to print on
+ * @offset: not used
+ */
+int batadv_dat_cache_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->dat.hash;
+ struct batadv_dat_entry *dat_entry;
+ struct batadv_hard_iface *primary_if;
+ struct hlist_node *node;
+ struct hlist_head *head;
+ unsigned long last_seen_jiffies;
+ int last_seen_msecs, last_seen_secs, last_seen_mins;
+ uint32_t i;
+
+ primary_if = batadv_seq_print_text_primary_if_get(seq);
+ if (!primary_if)
+ goto out;
+
+ seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
+ seq_printf(seq, " %-7s %-13s %5s\n", "IPv4", "MAC",
+ "last-seen");
+
+ for (i = 0; i < hash->size; i++) {
+ head = &hash->table[i];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(dat_entry, node, head, hash_entry) {
+ last_seen_jiffies = jiffies - dat_entry->last_update;
+ last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
+ last_seen_mins = last_seen_msecs / 60000;
+ last_seen_msecs = last_seen_msecs % 60000;
+ last_seen_secs = last_seen_msecs / 1000;
+
+ seq_printf(seq, " * %15pI4 %14pM %6i:%02i\n",
+ &dat_entry->ip, dat_entry->mac_addr,
+ last_seen_mins, last_seen_secs);
+ }
+ rcu_read_unlock();
+ }
+
+out:
+ if (primary_if)
+ batadv_hardif_free_ref(primary_if);
+ return 0;
+}