/**
* batadv_check_claim_group
* @bat_priv: the bat priv with all the soft interface information
* @primary_if: the primary interface of this batman interface
* @hw_src: the Hardware source in the ARP Header
* @hw_dst: the Hardware destination in the ARP Header
* @ethhdr: pointer to the Ethernet header of the claim frame
*
* checks if it is a claim packet and if its on the same group.
* This function also applies the group ID of the sender
* if it is in the same mesh.
*
* returns:
* 2 - if it is a claim packet and on the same group
* 1 - if is a claim packet from another group
* 0 - if it is not a claim packet
*/
static int batadv_check_claim_group(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
uint8_t *hw_src, uint8_t *hw_dst,
struct ethhdr *ethhdr)
{
uint8_t *backbone_addr;
struct batadv_orig_node *orig_node;
struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
bla_dst_own = &bat_priv->bla.claim_dest;
/* if announcement packet, use the source,
* otherwise assume it is in the hw_src
*/
switch (bla_dst->type) {
case BATADV_CLAIM_TYPE_CLAIM:
backbone_addr = hw_src;
break;
case BATADV_CLAIM_TYPE_REQUEST:
case BATADV_CLAIM_TYPE_ANNOUNCE:
case BATADV_CLAIM_TYPE_UNCLAIM:
backbone_addr = ethhdr->h_source;
break;
default:
return 0;
}
/* don't accept claim frames from ourselves */
if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
return 0;
/* if its already the same group, it is fine. */
if (bla_dst->group == bla_dst_own->group)
return 2;
/* lets see if this originator is in our mesh */
orig_node = batadv_orig_hash_find(bat_priv, backbone_addr);
/* dont accept claims from gateways which are not in
* the same mesh or group.
*/
if (!orig_node)
return 1;
/* if our mesh friends mac is bigger, use it for ourselves. */
if (ntohs(bla_dst->group) > ntohs(bla_dst_own->group)) {
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"taking other backbones claim group: %#.4x\n",
ntohs(bla_dst->group));
bla_dst_own->group = bla_dst->group;
}
batadv_orig_node_free_ref(orig_node);
return 2;
}
/**
* batadv_bla_get_backbone_gw
* @bat_priv: the bat priv with all the soft interface information
* @orig: the mac address of the originator
* @vid: the VLAN ID
*
* searches for the backbone gw or creates a new one if it could not
* be found.
*/
static struct batadv_backbone_gw *
batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, uint8_t *orig,
short vid)
{
struct batadv_backbone_gw *entry;
struct batadv_orig_node *orig_node;
int hash_added;
entry = batadv_backbone_hash_find(bat_priv, orig, vid);
if (entry)
return entry;
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_get_backbone_gw(): not found (%pM, %d), creating new entry\n",
orig, vid);
entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
if (!entry)
return NULL;
entry->vid = vid;
entry->lasttime = jiffies;
entry->crc = BATADV_BLA_CRC_INIT;
entry->bat_priv = bat_priv;
atomic_set(&entry->request_sent, 0);
memcpy(entry->orig, orig, ETH_ALEN);
/* one for the hash, one for returning */
atomic_set(&entry->refcount, 2);
hash_added = batadv_hash_add(bat_priv->bla.backbone_hash,
batadv_compare_backbone_gw,
batadv_choose_backbone_gw, entry,
&entry->hash_entry);
if (unlikely(hash_added != 0)) {
/* hash failed, free the structure */
kfree(entry);
return NULL;
}
/* this is a gateway now, remove any tt entries */
orig_node = batadv_orig_hash_find(bat_priv, orig);
if (orig_node) {
batadv_tt_global_del_orig(bat_priv, orig_node,
"became a backbone gateway");
batadv_orig_node_free_ref(orig_node);
}
return entry;
}
/**
* batadv_choose_next_candidate - select the next DHT candidate
* @bat_priv: the bat priv with all the soft interface information
* @cands: candidates array
* @select: number of candidates already present in the array
* @ip_key: key to look up in the DHT
* @last_max: pointer where the address of the selected candidate will be saved
*/
static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
struct batadv_dat_candidate *cands,
int select, batadv_dat_addr_t ip_key,
batadv_dat_addr_t *last_max)
{
batadv_dat_addr_t max = 0, tmp_max = 0;
struct batadv_orig_node *orig_node, *max_orig_node = NULL;
struct batadv_hashtable *hash = bat_priv->orig_hash;
struct hlist_node *node;
struct hlist_head *head;
int i;
/* if no node is eligible as candidate, leave the candidate type as
* NOT_FOUND
*/
cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
/* iterate over the originator list and find the node with closest
* dat_address which has not been selected yet
*/
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
rcu_read_lock();
hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
/* the dht space is a ring and addresses are unsigned */
tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
ip_key;
if (!batadv_is_orig_node_eligible(cands, select,
tmp_max, max,
*last_max, orig_node,
max_orig_node))
continue;
if (!atomic_inc_not_zero(&orig_node->refcount))
continue;
max = tmp_max;
if (max_orig_node)
batadv_orig_node_free_ref(max_orig_node);
max_orig_node = orig_node;
}
rcu_read_unlock();
}
/**
* batadv_bla_get_backbone_gw
* @bat_priv: the bat priv with all the soft interface information
* @orig: the mac address of the originator
* @vid: the VLAN ID
* @own_backbone: set if the requested backbone is local
*
* searches for the backbone gw or creates a new one if it could not
* be found.
*/
static struct batadv_bla_backbone_gw *
batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, uint8_t *orig,
unsigned short vid, bool own_backbone)
{
struct batadv_bla_backbone_gw *entry;
struct batadv_orig_node *orig_node;
int hash_added;
entry = batadv_backbone_hash_find(bat_priv, orig, vid);
if (entry)
return entry;
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_get_backbone_gw(): not found (%pM, %d), creating new entry\n",
orig, BATADV_PRINT_VID(vid));
entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
if (!entry)
return NULL;
entry->vid = vid;
entry->lasttime = jiffies;
entry->crc = BATADV_BLA_CRC_INIT;
entry->bat_priv = bat_priv;
atomic_set(&entry->request_sent, 0);
atomic_set(&entry->wait_periods, 0);
ether_addr_copy(entry->orig, orig);
/* one for the hash, one for returning */
atomic_set(&entry->refcount, 2);
hash_added = batadv_hash_add(bat_priv->bla.backbone_hash,
batadv_compare_backbone_gw,
batadv_choose_backbone_gw, entry,
&entry->hash_entry);
if (unlikely(hash_added != 0)) {
/* hash failed, free the structure */
kfree(entry);
return NULL;
}
/* this is a gateway now, remove any TT entry on this VLAN */
orig_node = batadv_orig_hash_find(bat_priv, orig);
if (orig_node) {
batadv_tt_global_del_orig(bat_priv, orig_node, vid,
"became a backbone gateway");
batadv_orig_node_free_ref(orig_node);
}
if (own_backbone) {
batadv_bla_send_announce(bat_priv, entry);
/* this will be decreased in the worker thread */
atomic_inc(&entry->request_sent);
atomic_set(&entry->wait_periods, BATADV_BLA_WAIT_PERIODS);
atomic_inc(&bat_priv->bla.num_requests);
}
return entry;
}
