batman-adv: Distributed ARP Table - create DHT helper functions
Add all the relevant functions in order to manage a Distributed Hash Table over the B.A.T.M.A.N.-adv network. It will later be used to store several ARP entries and implement DAT (Distributed ARP Table) Signed-off-by: Antonio Quartulli <ordex@autistici.org>
This commit is contained in:
Antonio Quartulli
parent
0e861a3c4f
commit
785ea11441
|
|
@ -23,6 +23,7 @@ batman-adv-y += bat_iv_ogm.o
|
|||
batman-adv-y += bitarray.o
|
||||
batman-adv-$(CONFIG_BATMAN_ADV_BLA) += bridge_loop_avoidance.o
|
||||
batman-adv-y += debugfs.o
|
||||
batman-adv-y += distributed-arp-table.o
|
||||
batman-adv-y += gateway_client.o
|
||||
batman-adv-y += gateway_common.o
|
||||
batman-adv-y += hard-interface.o
|
||||
|
|
|
|||
|
|
@ -0,0 +1,270 @@
|
|||
/* Copyright (C) 2011-2012 B.A.T.M.A.N. contributors:
|
||||
*
|
||||
* Antonio Quartulli
|
||||
*
|
||||
* 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, write to the Free Software
|
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
||||
* 02110-1301, USA
|
||||
*/
|
||||
|
||||
#include <linux/if_ether.h>
|
||||
#include <linux/if_arp.h>
|
||||
|
||||
#include "main.h"
|
||||
#include "distributed-arp-table.h"
|
||||
#include "hard-interface.h"
|
||||
#include "originator.h"
|
||||
#include "send.h"
|
||||
#include "types.h"
|
||||
#include "unicast.h"
|
||||
|
||||
/**
|
||||
* batadv_hash_dat - compute the hash value for an IP address
|
||||
* @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_hash_dat(const void *data, uint32_t size)
|
||||
{
|
||||
const unsigned char *key = data;
|
||||
uint32_t hash = 0;
|
||||
size_t i;
|
||||
|
||||
for (i = 0; i < 4; i++) {
|
||||
hash += key[i];
|
||||
hash += (hash << 10);
|
||||
hash ^= (hash >> 6);
|
||||
}
|
||||
|
||||
hash += (hash << 3);
|
||||
hash ^= (hash >> 11);
|
||||
hash += (hash << 15);
|
||||
|
||||
return hash % size;
|
||||
}
|
||||
|
||||
/**
|
||||
* 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
|
||||
* @tmp_max: address of the currently evaluated node
|
||||
* @max: current round max address
|
||||
* @last_max: address of the last selected candidate
|
||||
* @candidate: orig_node under evaluation
|
||||
* @max_orig_node: last selected candidate
|
||||
*
|
||||
* Returns true if the node has been elected as next candidate or false othrwise
|
||||
*/
|
||||
static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
|
||||
int select, batadv_dat_addr_t tmp_max,
|
||||
batadv_dat_addr_t max,
|
||||
batadv_dat_addr_t last_max,
|
||||
struct batadv_orig_node *candidate,
|
||||
struct batadv_orig_node *max_orig_node)
|
||||
{
|
||||
bool ret = false;
|
||||
int j;
|
||||
|
||||
/* Check if this node has already been selected... */
|
||||
for (j = 0; j < select; j++)
|
||||
if (res[j].orig_node == candidate)
|
||||
break;
|
||||
/* ..and possibly skip it */
|
||||
if (j < select)
|
||||
goto out;
|
||||
/* sanity check: has it already been selected? This should not happen */
|
||||
if (tmp_max > last_max)
|
||||
goto out;
|
||||
/* check if during this iteration an originator with a closer dht
|
||||
* address has already been found
|
||||
*/
|
||||
if (tmp_max < max)
|
||||
goto out;
|
||||
/* this is an hash collision with the temporary selected node. Choose
|
||||
* the one with the lowest address
|
||||
*/
|
||||
if ((tmp_max == max) &&
|
||||
(batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
|
||||
goto out;
|
||||
|
||||
ret = true;
|
||||
out:
|
||||
return ret;
|
||||
}
|
||||
|
||||
/**
|
||||
* 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();
|
||||
}
|
||||
if (max_orig_node) {
|
||||
cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
|
||||
cands[select].orig_node = max_orig_node;
|
||||
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
||||
"dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
|
||||
select, max_orig_node->orig, max_orig_node->dat_addr,
|
||||
max);
|
||||
}
|
||||
*last_max = max;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_dat_select_candidates - selects the nodes which the DHT message has to
|
||||
* be sent to
|
||||
* @bat_priv: the bat priv with all the soft interface information
|
||||
* @ip_dst: ipv4 to look up in the DHT
|
||||
*
|
||||
* An originator O is selected if and only if its DHT_ID value is one of three
|
||||
* closest values (from the LEFT, with wrap around if needed) then the hash
|
||||
* value of the key. ip_dst is the key.
|
||||
*
|
||||
* Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM
|
||||
*/
|
||||
static struct batadv_dat_candidate *
|
||||
batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
|
||||
{
|
||||
int select;
|
||||
batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
|
||||
struct batadv_dat_candidate *res;
|
||||
|
||||
if (!bat_priv->orig_hash)
|
||||
return NULL;
|
||||
|
||||
res = kmalloc(BATADV_DAT_CANDIDATES_NUM * sizeof(*res), GFP_ATOMIC);
|
||||
if (!res)
|
||||
return NULL;
|
||||
|
||||
ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst,
|
||||
BATADV_DAT_ADDR_MAX);
|
||||
|
||||
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
||||
"dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst,
|
||||
ip_key);
|
||||
|
||||
for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
|
||||
batadv_choose_next_candidate(bat_priv, res, select, ip_key,
|
||||
&last_max);
|
||||
|
||||
return res;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_dat_send_data - send a payload to the selected candidates
|
||||
* @bat_priv: the bat priv with all the soft interface information
|
||||
* @skb: payload to send
|
||||
* @ip: the DHT key
|
||||
* @packet_subtype: unicast4addr packet subtype to use
|
||||
*
|
||||
* In this function the skb is copied by means of pskb_copy() and is sent as
|
||||
* unicast packet to each of the selected candidates
|
||||
*
|
||||
* Returns true if the packet is sent to at least one candidate, false otherwise
|
||||
*/
|
||||
static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
|
||||
struct sk_buff *skb, __be32 ip,
|
||||
int packet_subtype)
|
||||
{
|
||||
int i;
|
||||
bool ret = false;
|
||||
int send_status;
|
||||
struct batadv_neigh_node *neigh_node = NULL;
|
||||
struct sk_buff *tmp_skb;
|
||||
struct batadv_dat_candidate *cand;
|
||||
|
||||
cand = batadv_dat_select_candidates(bat_priv, ip);
|
||||
if (!cand)
|
||||
goto out;
|
||||
|
||||
batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
|
||||
|
||||
for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
|
||||
if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
|
||||
continue;
|
||||
|
||||
neigh_node = batadv_orig_node_get_router(cand[i].orig_node);
|
||||
if (!neigh_node)
|
||||
goto free_orig;
|
||||
|
||||
tmp_skb = pskb_copy(skb, GFP_ATOMIC);
|
||||
if (!batadv_unicast_4addr_prepare_skb(bat_priv, tmp_skb,
|
||||
cand[i].orig_node,
|
||||
packet_subtype)) {
|
||||
kfree_skb(tmp_skb);
|
||||
goto free_neigh;
|
||||
}
|
||||
|
||||
send_status = batadv_send_skb_packet(tmp_skb,
|
||||
neigh_node->if_incoming,
|
||||
neigh_node->addr);
|
||||
if (send_status == NET_XMIT_SUCCESS)
|
||||
/* packet sent to a candidate: return true */
|
||||
ret = true;
|
||||
free_neigh:
|
||||
batadv_neigh_node_free_ref(neigh_node);
|
||||
free_orig:
|
||||
batadv_orig_node_free_ref(cand[i].orig_node);
|
||||
}
|
||||
|
||||
out:
|
||||
kfree(cand);
|
||||
return ret;
|
||||
}
|
||||
|
|
@ -0,0 +1,58 @@
|
|||
/* Copyright (C) 2011-2012 B.A.T.M.A.N. contributors:
|
||||
*
|
||||
* Antonio Quartulli
|
||||
*
|
||||
* 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, write to the Free Software
|
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
||||
* 02110-1301, USA
|
||||
*/
|
||||
|
||||
#ifndef _NET_BATMAN_ADV_ARP_H_
|
||||
#define _NET_BATMAN_ADV_ARP_H_
|
||||
|
||||
#include "types.h"
|
||||
#include "originator.h"
|
||||
|
||||
#define BATADV_DAT_ADDR_MAX ((batadv_dat_addr_t)~(batadv_dat_addr_t)0)
|
||||
|
||||
/**
|
||||
* batadv_dat_init_orig_node_addr - assign a DAT address to the orig_node
|
||||
* @orig_node: the node to assign the DAT address to
|
||||
*/
|
||||
static inline void
|
||||
batadv_dat_init_orig_node_addr(struct batadv_orig_node *orig_node)
|
||||
{
|
||||
uint32_t addr;
|
||||
|
||||
addr = batadv_choose_orig(orig_node->orig, BATADV_DAT_ADDR_MAX);
|
||||
orig_node->dat_addr = (batadv_dat_addr_t)addr;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_dat_init_own_addr - assign a DAT address to the node itself
|
||||
* @bat_priv: the bat priv with all the soft interface information
|
||||
* @primary_if: a pointer to the primary interface
|
||||
*/
|
||||
static inline void
|
||||
batadv_dat_init_own_addr(struct batadv_priv *bat_priv,
|
||||
struct batadv_hard_iface *primary_if)
|
||||
{
|
||||
uint32_t addr;
|
||||
|
||||
addr = batadv_choose_orig(primary_if->net_dev->dev_addr,
|
||||
BATADV_DAT_ADDR_MAX);
|
||||
|
||||
bat_priv->dat.addr = (batadv_dat_addr_t)addr;
|
||||
}
|
||||
|
||||
#endif /* _NET_BATMAN_ADV_ARP_H_ */
|
||||
|
|
@ -18,6 +18,7 @@
|
|||
*/
|
||||
|
||||
#include "main.h"
|
||||
#include "distributed-arp-table.h"
|
||||
#include "hard-interface.h"
|
||||
#include "soft-interface.h"
|
||||
#include "send.h"
|
||||
|
|
@ -109,6 +110,8 @@ static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
|
|||
if (!primary_if)
|
||||
goto out;
|
||||
|
||||
batadv_dat_init_own_addr(bat_priv, primary_if);
|
||||
|
||||
skb = bat_priv->vis.my_info->skb_packet;
|
||||
vis_packet = (struct batadv_vis_packet *)skb->data;
|
||||
memcpy(vis_packet->vis_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
|
||||
|
|
|
|||
|
|
@ -73,6 +73,9 @@
|
|||
|
||||
#define BATADV_LOG_BUF_LEN 8192 /* has to be a power of 2 */
|
||||
|
||||
/* numbers of originator to contact for any PUT/GET DHT operation */
|
||||
#define BATADV_DAT_CANDIDATES_NUM 3
|
||||
|
||||
#define BATADV_VIS_INTERVAL 5000 /* 5 seconds */
|
||||
|
||||
/* how much worse secondary interfaces may be to be considered as bonding
|
||||
|
|
@ -117,6 +120,9 @@ enum batadv_uev_type {
|
|||
|
||||
#define BATADV_GW_THRESHOLD 50
|
||||
|
||||
#define BATADV_DAT_CANDIDATE_NOT_FOUND 0
|
||||
#define BATADV_DAT_CANDIDATE_ORIG 1
|
||||
|
||||
/* Debug Messages */
|
||||
#ifdef pr_fmt
|
||||
#undef pr_fmt
|
||||
|
|
|
|||
|
|
@ -18,6 +18,7 @@
|
|||
*/
|
||||
|
||||
#include "main.h"
|
||||
#include "distributed-arp-table.h"
|
||||
#include "originator.h"
|
||||
#include "hash.h"
|
||||
#include "translation-table.h"
|
||||
|
|
@ -223,6 +224,7 @@ struct batadv_orig_node *batadv_get_orig_node(struct batadv_priv *bat_priv,
|
|||
orig_node->tt_poss_change = false;
|
||||
orig_node->bat_priv = bat_priv;
|
||||
memcpy(orig_node->orig, addr, ETH_ALEN);
|
||||
batadv_dat_init_orig_node_addr(orig_node);
|
||||
orig_node->router = NULL;
|
||||
orig_node->tt_crc = 0;
|
||||
atomic_set(&orig_node->last_ttvn, 0);
|
||||
|
|
|
|||
|
|
@ -28,6 +28,13 @@
|
|||
(ETH_HLEN + max(sizeof(struct batadv_unicast_packet), \
|
||||
sizeof(struct batadv_bcast_packet)))
|
||||
|
||||
/* batadv_dat_addr_t is the type used for all DHT addresses. If it is changed,
|
||||
* BATADV_DAT_ADDR_MAX is changed as well.
|
||||
*
|
||||
* *Please be careful: batadv_dat_addr_t must be UNSIGNED*
|
||||
*/
|
||||
#define batadv_dat_addr_t uint16_t
|
||||
|
||||
/**
|
||||
* struct batadv_hard_iface_bat_iv - per hard interface B.A.T.M.A.N. IV data
|
||||
* @ogm_buff: buffer holding the OGM packet
|
||||
|
|
@ -73,6 +80,7 @@ struct batadv_orig_node {
|
|||
uint8_t orig[ETH_ALEN];
|
||||
uint8_t primary_addr[ETH_ALEN];
|
||||
struct batadv_neigh_node __rcu *router; /* rcu protected pointer */
|
||||
batadv_dat_addr_t dat_addr;
|
||||
unsigned long *bcast_own;
|
||||
uint8_t *bcast_own_sum;
|
||||
unsigned long last_seen;
|
||||
|
|
@ -238,6 +246,14 @@ struct batadv_priv_vis {
|
|||
struct batadv_vis_info *my_info;
|
||||
};
|
||||
|
||||
/**
|
||||
* struct batadv_priv_dat - per mesh interface DAT private data
|
||||
* @addr: node DAT address
|
||||
*/
|
||||
struct batadv_priv_dat {
|
||||
batadv_dat_addr_t addr;
|
||||
};
|
||||
|
||||
struct batadv_priv {
|
||||
atomic_t mesh_state;
|
||||
struct net_device_stats stats;
|
||||
|
|
@ -275,6 +291,7 @@ struct batadv_priv {
|
|||
struct batadv_priv_gw gw;
|
||||
struct batadv_priv_tt tt;
|
||||
struct batadv_priv_vis vis;
|
||||
struct batadv_priv_dat dat;
|
||||
};
|
||||
|
||||
struct batadv_socket_client {
|
||||
|
|
@ -447,4 +464,17 @@ struct batadv_algo_ops {
|
|||
void (*bat_ogm_emit)(struct batadv_forw_packet *forw_packet);
|
||||
};
|
||||
|
||||
/**
|
||||
* 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
|
||||
* - BATADV_DAT_CANDIDATE_ORIG
|
||||
* @orig_node: if type is BATADV_DAT_CANDIDATE_ORIG this field points to the
|
||||
* corresponding originator node structure
|
||||
*/
|
||||
struct batadv_dat_candidate {
|
||||
int type;
|
||||
struct batadv_orig_node *orig_node;
|
||||
};
|
||||
|
||||
#endif /* _NET_BATMAN_ADV_TYPES_H_ */
|
||||
|
|
|
|||
|
|
@ -347,10 +347,10 @@ static bool batadv_unicast_prepare_skb(struct sk_buff *skb,
|
|||
*
|
||||
* Returns false if the payload could not be encapsulated or true otherwise
|
||||
*/
|
||||
static bool batadv_unicast_4addr_prepare_skb(struct batadv_priv *bat_priv,
|
||||
struct sk_buff *skb,
|
||||
struct batadv_orig_node *orig,
|
||||
int packet_subtype)
|
||||
bool batadv_unicast_4addr_prepare_skb(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 *unicast_4addr_packet;
|
||||
|
|
|
|||
|
|
@ -32,6 +32,10 @@ void batadv_frag_list_free(struct list_head *head);
|
|||
int batadv_frag_send_skb(struct sk_buff *skb, struct batadv_priv *bat_priv,
|
||||
struct batadv_hard_iface *hard_iface,
|
||||
const uint8_t dstaddr[]);
|
||||
bool batadv_unicast_4addr_prepare_skb(struct batadv_priv *bat_priv,
|
||||
struct sk_buff *skb,
|
||||
struct batadv_orig_node *orig_node,
|
||||
int packet_subtype);
|
||||
int batadv_unicast_generic_send_skb(struct batadv_priv *bat_priv,
|
||||
struct sk_buff *skb, int packet_type,
|
||||
int packet_subtype);
|
||||
|
|
|
|||
Reference in New Issue