The following commit has been merged in the master branch: commit 2f1dfbe185075a50dc8f0490a136377af53a1c62 Author: Antonio Quartulli ordex@autistici.org Date: Sat Jun 30 20:01:19 2012 +0200

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

diff --git a/net/batman-adv/debugfs.c b/net/batman-adv/debugfs.c index bd032bc..ebc5f4d 100644 --- a/net/batman-adv/debugfs.c +++ b/net/batman-adv/debugfs.c @@ -31,6 +31,7 @@ #include "vis.h" #include "icmp_socket.h" #include "bridge_loop_avoidance.h" +#include "distributed-arp-table.h"

static struct dentry *batadv_debugfs;

@@ -280,6 +281,18 @@ static int batadv_bla_backbone_table_open(struct inode *inode,

#endif

+/** + * batadv_dat_cache_open - Prepare file handler for reads from dat_chache + * @inode: inode which was opened + * @file: file handle to be initialized + */ +static int batadv_dat_cache_open(struct inode *inode, struct file *file) +{ + struct net_device *net_dev = (struct net_device *)inode->i_private; + return single_open(file, batadv_dat_cache_seq_print_text, net_dev); +} + + static int batadv_transtable_local_open(struct inode *inode, struct file *file) { struct net_device *net_dev = (struct net_device *)inode->i_private; @@ -319,6 +332,7 @@ static BATADV_DEBUGINFO(bla_claim_table, S_IRUGO, batadv_bla_claim_table_open); static BATADV_DEBUGINFO(bla_backbone_table, S_IRUGO, batadv_bla_backbone_table_open); #endif +static BATADV_DEBUGINFO(dat_cache, S_IRUGO, batadv_dat_cache_open); static BATADV_DEBUGINFO(transtable_local, S_IRUGO, batadv_transtable_local_open); static BATADV_DEBUGINFO(vis_data, S_IRUGO, batadv_vis_data_open); @@ -331,6 +345,7 @@ static struct batadv_debuginfo *batadv_mesh_debuginfos[] = { &batadv_debuginfo_bla_claim_table, &batadv_debuginfo_bla_backbone_table, #endif + &batadv_debuginfo_dat_cache, &batadv_debuginfo_transtable_local, &batadv_debuginfo_vis_data, NULL, diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index ce39e8a..2ef90e3 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; +} diff --git a/net/batman-adv/distributed-arp-table.h b/net/batman-adv/distributed-arp-table.h index ea9cbd8..1b88303 100644 --- a/net/batman-adv/distributed-arp-table.h +++ b/net/batman-adv/distributed-arp-table.h @@ -55,4 +55,8 @@ batadv_dat_init_own_addr(struct batadv_priv *bat_priv, bat_priv->dat.addr = (batadv_dat_addr_t)addr; }

+int batadv_dat_init(struct batadv_priv *bat_priv); +void batadv_dat_free(struct batadv_priv *bat_priv); +int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset); + #endif /* _NET_BATMAN_ADV_ARP_H_ */ diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index afc07a8..dc33a0c 100644 --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -29,6 +29,7 @@ #include "hard-interface.h" #include "gateway_client.h" #include "bridge_loop_avoidance.h" +#include "distributed-arp-table.h" #include "vis.h" #include "hash.h" #include "bat_algo.h" @@ -128,6 +129,10 @@ int batadv_mesh_init(struct net_device *soft_iface) if (ret < 0) goto err;

+ ret = batadv_dat_init(bat_priv); + if (ret < 0) + goto err; + atomic_set(&bat_priv->gw.reselect, 0); atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);

@@ -155,6 +160,8 @@ void batadv_mesh_free(struct net_device *soft_iface)

batadv_bla_free(bat_priv);

+ batadv_dat_free(bat_priv); + free_percpu(bat_priv->bat_counters);

atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE); diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h index 5699f2b..25adfd2 100644 --- a/net/batman-adv/main.h +++ b/net/batman-adv/main.h @@ -44,6 +44,7 @@ #define BATADV_TT_LOCAL_TIMEOUT 3600000 /* in milliseconds */ #define BATADV_TT_CLIENT_ROAM_TIMEOUT 600000 /* in milliseconds */ #define BATADV_TT_CLIENT_TEMP_TIMEOUT 600000 /* in milliseconds */ +#define BATADV_DAT_ENTRY_TIMEOUT (5*60000) /* 5 mins in milliseconds */ /* sliding packet range of received originator messages in sequence numbers * (should be a multiple of our word size) */ diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index b57d93b..9ed1bb2 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -249,9 +249,13 @@ struct batadv_priv_vis { /** * struct batadv_priv_dat - per mesh interface DAT private data * @addr: node DAT address + * @hash: hashtable representing the local ARP cache + * @work: work queue callback item for cache purging */ struct batadv_priv_dat { batadv_dat_addr_t addr; + struct batadv_hashtable *hash; + struct delayed_work work; };

struct batadv_priv { @@ -465,6 +469,25 @@ struct batadv_algo_ops { };

/** + * struct batadv_dat_entry - it is a single entry of batman-adv ARP backend. It + * is used to stored ARP entries needed for the global DAT cache + * @ip: the IPv4 corresponding to this DAT/ARP entry + * @mac_addr: the MAC address associated to the stored IPv4 + * @last_update: time in jiffies when this entry was refreshed last time + * @hash_entry: hlist node for batadv_priv_dat::hash + * @refcount: number of contexts the object is used + * @rcu: struct used for freeing in an RCU-safe manner + */ +struct batadv_dat_entry { + __be32 ip; + uint8_t mac_addr[ETH_ALEN]; + unsigned long last_update; + struct hlist_node hash_entry; + atomic_t refcount; + struct rcu_head rcu; +}; + +/** * struct batadv_dat_candidate - candidate destination for DAT operations * @type: the type of the selected candidate. It can one of the following: * - BATADV_DAT_CANDIDATE_NOT_FOUND