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OpenCloudOS-Kernel/net/batman-adv/bridge_loop_avoidance.c

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/* Copyright (C) 2011-2016 B.A.T.M.A.N. contributors:
*
* Simon Wunderlich
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include "bridge_loop_avoidance.h"
#include "main.h"
#include <linux/atomic.h>
#include <linux/byteorder/generic.h>
#include <linux/compiler.h>
#include <linux/crc16.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/fs.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/jhash.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/netdevice.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/seq_file.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/workqueue.h>
#include <net/arp.h>
#include "hard-interface.h"
#include "hash.h"
#include "originator.h"
#include "packet.h"
#include "sysfs.h"
#include "translation-table.h"
static const u8 batadv_announce_mac[4] = {0x43, 0x05, 0x43, 0x05};
static void batadv_bla_periodic_work(struct work_struct *work);
static void
batadv_bla_send_announce(struct batadv_priv *bat_priv,
struct batadv_bla_backbone_gw *backbone_gw);
/**
* batadv_choose_claim - choose the right bucket for a claim.
* @data: data to hash
* @size: size of the hash table
*
* Return: the hash index of the claim
*/
static inline u32 batadv_choose_claim(const void *data, u32 size)
{
struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data;
u32 hash = 0;
hash = jhash(&claim->addr, sizeof(claim->addr), hash);
hash = jhash(&claim->vid, sizeof(claim->vid), hash);
return hash % size;
}
/**
* batadv_choose_backbone_gw - choose the right bucket for a backbone gateway.
* @data: data to hash
* @size: size of the hash table
*
* Return: the hash index of the backbone gateway
*/
static inline u32 batadv_choose_backbone_gw(const void *data, u32 size)
{
const struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data;
u32 hash = 0;
hash = jhash(&claim->addr, sizeof(claim->addr), hash);
hash = jhash(&claim->vid, sizeof(claim->vid), hash);
return hash % size;
}
/**
* batadv_compare_backbone_gw - compare address and vid of two backbone gws
* @node: list node of the first entry to compare
* @data2: pointer to the second backbone gateway
*
* Return: true if the backbones have the same data, false otherwise
*/
static bool batadv_compare_backbone_gw(const struct hlist_node *node,
const void *data2)
{
const void *data1 = container_of(node, struct batadv_bla_backbone_gw,
hash_entry);
const struct batadv_bla_backbone_gw *gw1 = data1;
const struct batadv_bla_backbone_gw *gw2 = data2;
if (!batadv_compare_eth(gw1->orig, gw2->orig))
return false;
if (gw1->vid != gw2->vid)
return false;
return true;
}
/**
* batadv_compare_claim - compare address and vid of two claims
* @node: list node of the first entry to compare
* @data2: pointer to the second claims
*
* Return: true if the claim have the same data, 0 otherwise
*/
static bool batadv_compare_claim(const struct hlist_node *node,
const void *data2)
{
const void *data1 = container_of(node, struct batadv_bla_claim,
hash_entry);
const struct batadv_bla_claim *cl1 = data1;
const struct batadv_bla_claim *cl2 = data2;
if (!batadv_compare_eth(cl1->addr, cl2->addr))
return false;
if (cl1->vid != cl2->vid)
return false;
return true;
}
/**
* batadv_backbone_gw_release - release backbone gw from lists and queue for
* free after rcu grace period
* @ref: kref pointer of the backbone gw
*/
static void batadv_backbone_gw_release(struct kref *ref)
{
struct batadv_bla_backbone_gw *backbone_gw;
backbone_gw = container_of(ref, struct batadv_bla_backbone_gw,
refcount);
kfree_rcu(backbone_gw, rcu);
}
/**
* batadv_backbone_gw_put - decrement the backbone gw refcounter and possibly
* release it
* @backbone_gw: backbone gateway to be free'd
*/
static void batadv_backbone_gw_put(struct batadv_bla_backbone_gw *backbone_gw)
{
kref_put(&backbone_gw->refcount, batadv_backbone_gw_release);
}
/**
* batadv_claim_release - release claim from lists and queue for free after rcu
* grace period
* @ref: kref pointer of the claim
*/
static void batadv_claim_release(struct kref *ref)
{
struct batadv_bla_claim *claim;
claim = container_of(ref, struct batadv_bla_claim, refcount);
batadv_backbone_gw_put(claim->backbone_gw);
kfree_rcu(claim, rcu);
}
/**
* batadv_claim_put - decrement the claim refcounter and possibly
* release it
* @claim: claim to be free'd
*/
static void batadv_claim_put(struct batadv_bla_claim *claim)
{
kref_put(&claim->refcount, batadv_claim_release);
}
/**
* batadv_claim_hash_find - looks for a claim in the claim hash
* @bat_priv: the bat priv with all the soft interface information
* @data: search data (may be local/static data)
*
* Return: claim if found or NULL otherwise.
*/
static struct batadv_bla_claim *
batadv_claim_hash_find(struct batadv_priv *bat_priv,
struct batadv_bla_claim *data)
{
struct batadv_hashtable *hash = bat_priv->bla.claim_hash;
struct hlist_head *head;
struct batadv_bla_claim *claim;
struct batadv_bla_claim *claim_tmp = NULL;
int index;
if (!hash)
return NULL;
index = batadv_choose_claim(data, hash->size);
head = &hash->table[index];
rcu_read_lock();
hlist_for_each_entry_rcu(claim, head, hash_entry) {
if (!batadv_compare_claim(&claim->hash_entry, data))
continue;
if (!kref_get_unless_zero(&claim->refcount))
continue;
claim_tmp = claim;
break;
}
rcu_read_unlock();
return claim_tmp;
}
/**
* batadv_backbone_hash_find - looks for a backbone gateway in the hash
* @bat_priv: the bat priv with all the soft interface information
* @addr: the address of the originator
* @vid: the VLAN ID
*
* Return: backbone gateway if found or NULL otherwise
*/
static struct batadv_bla_backbone_gw *
batadv_backbone_hash_find(struct batadv_priv *bat_priv, u8 *addr,
unsigned short vid)
{
struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
struct hlist_head *head;
struct batadv_bla_backbone_gw search_entry, *backbone_gw;
struct batadv_bla_backbone_gw *backbone_gw_tmp = NULL;
int index;
if (!hash)
return NULL;
ether_addr_copy(search_entry.orig, addr);
search_entry.vid = vid;
index = batadv_choose_backbone_gw(&search_entry, hash->size);
head = &hash->table[index];
rcu_read_lock();
hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
if (!batadv_compare_backbone_gw(&backbone_gw->hash_entry,
&search_entry))
continue;
if (!kref_get_unless_zero(&backbone_gw->refcount))
continue;
backbone_gw_tmp = backbone_gw;
break;
}
rcu_read_unlock();
return backbone_gw_tmp;
}
/**
* batadv_bla_del_backbone_claims - delete all claims for a backbone
* @backbone_gw: backbone gateway where the claims should be removed
*/
static void
batadv_bla_del_backbone_claims(struct batadv_bla_backbone_gw *backbone_gw)
{
struct batadv_hashtable *hash;
struct hlist_node *node_tmp;
struct hlist_head *head;
struct batadv_bla_claim *claim;
int i;
spinlock_t *list_lock; /* protects write access to the hash lists */
hash = backbone_gw->bat_priv->bla.claim_hash;
if (!hash)
return;
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
list_lock = &hash->list_locks[i];
spin_lock_bh(list_lock);
hlist_for_each_entry_safe(claim, node_tmp,
head, hash_entry) {
if (claim->backbone_gw != backbone_gw)
continue;
batadv_claim_put(claim);
hlist_del_rcu(&claim->hash_entry);
}
spin_unlock_bh(list_lock);
}
/* all claims gone, initialize CRC */
spin_lock_bh(&backbone_gw->crc_lock);
backbone_gw->crc = BATADV_BLA_CRC_INIT;
spin_unlock_bh(&backbone_gw->crc_lock);
}
/**
* batadv_bla_send_claim - sends a claim frame according to the provided info
* @bat_priv: the bat priv with all the soft interface information
* @mac: the mac address to be announced within the claim
* @vid: the VLAN ID
* @claimtype: the type of the claim (CLAIM, UNCLAIM, ANNOUNCE, ...)
*/
static void batadv_bla_send_claim(struct batadv_priv *bat_priv, u8 *mac,
unsigned short vid, int claimtype)
{
struct sk_buff *skb;
struct ethhdr *ethhdr;
struct batadv_hard_iface *primary_if;
struct net_device *soft_iface;
u8 *hw_src;
struct batadv_bla_claim_dst local_claim_dest;
__be32 zeroip = 0;
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
return;
memcpy(&local_claim_dest, &bat_priv->bla.claim_dest,
sizeof(local_claim_dest));
local_claim_dest.type = claimtype;
soft_iface = primary_if->soft_iface;
skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
/* IP DST: 0.0.0.0 */
zeroip,
primary_if->soft_iface,
/* IP SRC: 0.0.0.0 */
zeroip,
/* Ethernet DST: Broadcast */
NULL,
/* Ethernet SRC/HW SRC: originator mac */
primary_if->net_dev->dev_addr,
/* HW DST: FF:43:05:XX:YY:YY
* with XX = claim type
* and YY:YY = group id
*/
(u8 *)&local_claim_dest);
if (!skb)
goto out;
ethhdr = (struct ethhdr *)skb->data;
hw_src = (u8 *)ethhdr + ETH_HLEN + sizeof(struct arphdr);
/* now we pretend that the client would have sent this ... */
switch (claimtype) {
case BATADV_CLAIM_TYPE_CLAIM:
/* normal claim frame
* set Ethernet SRC to the clients mac
*/
ether_addr_copy(ethhdr->h_source, mac);
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_send_claim(): CLAIM %pM on vid %d\n", mac,
BATADV_PRINT_VID(vid));
break;
case BATADV_CLAIM_TYPE_UNCLAIM:
/* unclaim frame
* set HW SRC to the clients mac
*/
ether_addr_copy(hw_src, mac);
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_send_claim(): UNCLAIM %pM on vid %d\n", mac,
BATADV_PRINT_VID(vid));
break;
case BATADV_CLAIM_TYPE_ANNOUNCE:
/* announcement frame
* set HW SRC to the special mac containg the crc
*/
ether_addr_copy(hw_src, mac);
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_send_claim(): ANNOUNCE of %pM on vid %d\n",
ethhdr->h_source, BATADV_PRINT_VID(vid));
break;
case BATADV_CLAIM_TYPE_REQUEST:
/* request frame
* set HW SRC and header destination to the receiving backbone
* gws mac
*/
ether_addr_copy(hw_src, mac);
ether_addr_copy(ethhdr->h_dest, mac);
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_send_claim(): REQUEST of %pM to %pM on vid %d\n",
ethhdr->h_source, ethhdr->h_dest,
BATADV_PRINT_VID(vid));
break;
case BATADV_CLAIM_TYPE_LOOPDETECT:
ether_addr_copy(ethhdr->h_source, mac);
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_send_claim(): LOOPDETECT of %pM to %pM on vid %d\n",
ethhdr->h_source, ethhdr->h_dest,
BATADV_PRINT_VID(vid));
break;
}
if (vid & BATADV_VLAN_HAS_TAG)
skb = vlan_insert_tag(skb, htons(ETH_P_8021Q),
vid & VLAN_VID_MASK);
skb_reset_mac_header(skb);
skb->protocol = eth_type_trans(skb, soft_iface);
batadv_inc_counter(bat_priv, BATADV_CNT_RX);
batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
skb->len + ETH_HLEN);
soft_iface->last_rx = jiffies;
netif_rx(skb);
out:
if (primary_if)
batadv_hardif_put(primary_if);
}
/**
* batadv_bla_loopdetect_report - worker for reporting the loop
* @work: work queue item
*
* Throws an uevent, as the loopdetect check function can't do that itself
* since the kernel may sleep while throwing uevents.
*/
static void batadv_bla_loopdetect_report(struct work_struct *work)
{
struct batadv_bla_backbone_gw *backbone_gw;
struct batadv_priv *bat_priv;
char vid_str[6] = { '\0' };
backbone_gw = container_of(work, struct batadv_bla_backbone_gw,
report_work);
bat_priv = backbone_gw->bat_priv;
batadv_info(bat_priv->soft_iface,
"Possible loop on VLAN %d detected which can't be handled by BLA - please check your network setup!\n",
BATADV_PRINT_VID(backbone_gw->vid));
snprintf(vid_str, sizeof(vid_str), "%d",
BATADV_PRINT_VID(backbone_gw->vid));
vid_str[sizeof(vid_str) - 1] = 0;
batadv_throw_uevent(bat_priv, BATADV_UEV_BLA, BATADV_UEV_LOOPDETECT,
vid_str);
batadv_backbone_gw_put(backbone_gw);
}
/**
* batadv_bla_get_backbone_gw - finds or creates a backbone gateway
* @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
*
* Return: the (possibly created) backbone gateway or NULL on error
*/
static struct batadv_bla_backbone_gw *
batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, u8 *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;
spin_lock_init(&entry->crc_lock);
atomic_set(&entry->request_sent, 0);
atomic_set(&entry->wait_periods, 0);
ether_addr_copy(entry->orig, orig);
INIT_WORK(&entry->report_work, batadv_bla_loopdetect_report);
/* one for the hash, one for returning */
kref_init(&entry->refcount);
kref_get(&entry->refcount);
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_put(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;
}
/**
* batadv_bla_update_own_backbone_gw - updates the own backbone gw for a VLAN
* @bat_priv: the bat priv with all the soft interface information
* @primary_if: the selected primary interface
* @vid: VLAN identifier
*
* update or add the own backbone gw to make sure we announce
* where we receive other backbone gws
*/
static void
batadv_bla_update_own_backbone_gw(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
unsigned short vid)
{
struct batadv_bla_backbone_gw *backbone_gw;
backbone_gw = batadv_bla_get_backbone_gw(bat_priv,
primary_if->net_dev->dev_addr,
vid, true);
if (unlikely(!backbone_gw))
return;
backbone_gw->lasttime = jiffies;
batadv_backbone_gw_put(backbone_gw);
}
/**
* batadv_bla_answer_request - answer a bla request by sending own claims
* @bat_priv: the bat priv with all the soft interface information
* @primary_if: interface where the request came on
* @vid: the vid where the request came on
*
* Repeat all of our own claims, and finally send an ANNOUNCE frame
* to allow the requester another check if the CRC is correct now.
*/
static void batadv_bla_answer_request(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
unsigned short vid)
{
struct hlist_head *head;
struct batadv_hashtable *hash;
struct batadv_bla_claim *claim;
struct batadv_bla_backbone_gw *backbone_gw;
int i;
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_answer_request(): received a claim request, send all of our own claims again\n");
backbone_gw = batadv_backbone_hash_find(bat_priv,
primary_if->net_dev->dev_addr,
vid);
if (!backbone_gw)
return;
hash = bat_priv->bla.claim_hash;
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
rcu_read_lock();
hlist_for_each_entry_rcu(claim, head, hash_entry) {
/* only own claims are interesting */
if (claim->backbone_gw != backbone_gw)
continue;
batadv_bla_send_claim(bat_priv, claim->addr, claim->vid,
BATADV_CLAIM_TYPE_CLAIM);
}
rcu_read_unlock();
}
/* finally, send an announcement frame */
batadv_bla_send_announce(bat_priv, backbone_gw);
batadv_backbone_gw_put(backbone_gw);
}
/**
* batadv_bla_send_request - send a request to repeat claims
* @backbone_gw: the backbone gateway from whom we are out of sync
*
* When the crc is wrong, ask the backbone gateway for a full table update.
* After the request, it will repeat all of his own claims and finally
* send an announcement claim with which we can check again.
*/
static void batadv_bla_send_request(struct batadv_bla_backbone_gw *backbone_gw)
{
/* first, remove all old entries */
batadv_bla_del_backbone_claims(backbone_gw);
batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
"Sending REQUEST to %pM\n", backbone_gw->orig);
/* send request */
batadv_bla_send_claim(backbone_gw->bat_priv, backbone_gw->orig,
backbone_gw->vid, BATADV_CLAIM_TYPE_REQUEST);
/* no local broadcasts should be sent or received, for now. */
if (!atomic_read(&backbone_gw->request_sent)) {
atomic_inc(&backbone_gw->bat_priv->bla.num_requests);
atomic_set(&backbone_gw->request_sent, 1);
}
}
/**
* batadv_bla_send_announce - Send an announcement frame
* @bat_priv: the bat priv with all the soft interface information
* @backbone_gw: our backbone gateway which should be announced
*/
static void batadv_bla_send_announce(struct batadv_priv *bat_priv,
struct batadv_bla_backbone_gw *backbone_gw)
{
u8 mac[ETH_ALEN];
__be16 crc;
memcpy(mac, batadv_announce_mac, 4);
spin_lock_bh(&backbone_gw->crc_lock);
crc = htons(backbone_gw->crc);
spin_unlock_bh(&backbone_gw->crc_lock);
memcpy(&mac[4], &crc, 2);
batadv_bla_send_claim(bat_priv, mac, backbone_gw->vid,
BATADV_CLAIM_TYPE_ANNOUNCE);
}
/**
* batadv_bla_add_claim - Adds a claim in the claim hash
* @bat_priv: the bat priv with all the soft interface information
* @mac: the mac address of the claim
* @vid: the VLAN ID of the frame
* @backbone_gw: the backbone gateway which claims it
*/
static void batadv_bla_add_claim(struct batadv_priv *bat_priv,
const u8 *mac, const unsigned short vid,
struct batadv_bla_backbone_gw *backbone_gw)
{
struct batadv_bla_claim *claim;
struct batadv_bla_claim search_claim;
int hash_added;
ether_addr_copy(search_claim.addr, mac);
search_claim.vid = vid;
claim = batadv_claim_hash_find(bat_priv, &search_claim);
/* create a new claim entry if it does not exist yet. */
if (!claim) {
claim = kzalloc(sizeof(*claim), GFP_ATOMIC);
if (!claim)
return;
ether_addr_copy(claim->addr, mac);
claim->vid = vid;
claim->lasttime = jiffies;
claim->backbone_gw = backbone_gw;
kref_init(&claim->refcount);
kref_get(&claim->refcount);
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_add_claim(): adding new entry %pM, vid %d to hash ...\n",
mac, BATADV_PRINT_VID(vid));
hash_added = batadv_hash_add(bat_priv->bla.claim_hash,
batadv_compare_claim,
batadv_choose_claim, claim,
&claim->hash_entry);
if (unlikely(hash_added != 0)) {
/* only local changes happened. */
kfree(claim);
return;
}
} else {
claim->lasttime = jiffies;
if (claim->backbone_gw == backbone_gw)
/* no need to register a new backbone */
goto claim_free_ref;
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_add_claim(): changing ownership for %pM, vid %d\n",
mac, BATADV_PRINT_VID(vid));
spin_lock_bh(&claim->backbone_gw->crc_lock);
claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
spin_unlock_bh(&claim->backbone_gw->crc_lock);
batadv_backbone_gw_put(claim->backbone_gw);
}
/* set (new) backbone gw */
kref_get(&backbone_gw->refcount);
claim->backbone_gw = backbone_gw;
spin_lock_bh(&backbone_gw->crc_lock);
backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
spin_unlock_bh(&backbone_gw->crc_lock);
backbone_gw->lasttime = jiffies;
claim_free_ref:
batadv_claim_put(claim);
}
/**
* batadv_bla_del_claim - delete a claim from the claim hash
* @bat_priv: the bat priv with all the soft interface information
* @mac: mac address of the claim to be removed
* @vid: VLAN id for the claim to be removed
*/
static void batadv_bla_del_claim(struct batadv_priv *bat_priv,
const u8 *mac, const unsigned short vid)
{
struct batadv_bla_claim search_claim, *claim;
ether_addr_copy(search_claim.addr, mac);
search_claim.vid = vid;
claim = batadv_claim_hash_find(bat_priv, &search_claim);
if (!claim)
return;
batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_del_claim(): %pM, vid %d\n",
mac, BATADV_PRINT_VID(vid));
batadv_hash_remove(bat_priv->bla.claim_hash, batadv_compare_claim,
batadv_choose_claim, claim);
batadv_claim_put(claim); /* reference from the hash is gone */
spin_lock_bh(&claim->backbone_gw->crc_lock);
claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
spin_unlock_bh(&claim->backbone_gw->crc_lock);
/* don't need the reference from hash_find() anymore */
batadv_claim_put(claim);
}
/**
* batadv_handle_announce - check for ANNOUNCE frame
* @bat_priv: the bat priv with all the soft interface information
* @an_addr: announcement mac address (ARP Sender HW address)
* @backbone_addr: originator address of the sender (Ethernet source MAC)
* @vid: the VLAN ID of the frame
*
* Return: true if handled
*/
static bool batadv_handle_announce(struct batadv_priv *bat_priv, u8 *an_addr,
u8 *backbone_addr, unsigned short vid)
{
struct batadv_bla_backbone_gw *backbone_gw;
u16 backbone_crc, crc;
if (memcmp(an_addr, batadv_announce_mac, 4) != 0)
return false;
backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid,
false);
if (unlikely(!backbone_gw))
return true;
/* handle as ANNOUNCE frame */
backbone_gw->lasttime = jiffies;
crc = ntohs(*((__be16 *)(&an_addr[4])));
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"handle_announce(): ANNOUNCE vid %d (sent by %pM)... CRC = %#.4x\n",
BATADV_PRINT_VID(vid), backbone_gw->orig, crc);
spin_lock_bh(&backbone_gw->crc_lock);
backbone_crc = backbone_gw->crc;
spin_unlock_bh(&backbone_gw->crc_lock);
if (backbone_crc != crc) {
batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
"handle_announce(): CRC FAILED for %pM/%d (my = %#.4x, sent = %#.4x)\n",
backbone_gw->orig,
BATADV_PRINT_VID(backbone_gw->vid),
backbone_crc, crc);
batadv_bla_send_request(backbone_gw);
} else {
/* if we have sent a request and the crc was OK,
* we can allow traffic again.
*/
if (atomic_read(&backbone_gw->request_sent)) {
atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
atomic_set(&backbone_gw->request_sent, 0);
}
}
batadv_backbone_gw_put(backbone_gw);
return true;
}
/**
* batadv_handle_request - check for REQUEST frame
* @bat_priv: the bat priv with all the soft interface information
* @primary_if: the primary hard interface of this batman soft interface
* @backbone_addr: backbone address to be requested (ARP sender HW MAC)
* @ethhdr: ethernet header of a packet
* @vid: the VLAN ID of the frame
*
* Return: true if handled
*/
static bool batadv_handle_request(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
u8 *backbone_addr, struct ethhdr *ethhdr,
unsigned short vid)
{
/* check for REQUEST frame */
if (!batadv_compare_eth(backbone_addr, ethhdr->h_dest))
return false;
/* sanity check, this should not happen on a normal switch,
* we ignore it in this case.
*/
if (!batadv_compare_eth(ethhdr->h_dest, primary_if->net_dev->dev_addr))
return true;
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"handle_request(): REQUEST vid %d (sent by %pM)...\n",
BATADV_PRINT_VID(vid), ethhdr->h_source);
batadv_bla_answer_request(bat_priv, primary_if, vid);
return true;
}
/**
* batadv_handle_unclaim - check for UNCLAIM frame
* @bat_priv: the bat priv with all the soft interface information
* @primary_if: the primary hard interface of this batman soft interface
* @backbone_addr: originator address of the backbone (Ethernet source)
* @claim_addr: Client to be unclaimed (ARP sender HW MAC)
* @vid: the VLAN ID of the frame
*
* Return: true if handled
*/
static bool batadv_handle_unclaim(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
u8 *backbone_addr, u8 *claim_addr,
unsigned short vid)
{
struct batadv_bla_backbone_gw *backbone_gw;
/* unclaim in any case if it is our own */
if (primary_if && batadv_compare_eth(backbone_addr,
primary_if->net_dev->dev_addr))
batadv_bla_send_claim(bat_priv, claim_addr, vid,
BATADV_CLAIM_TYPE_UNCLAIM);
backbone_gw = batadv_backbone_hash_find(bat_priv, backbone_addr, vid);
if (!backbone_gw)
return true;
/* this must be an UNCLAIM frame */
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"handle_unclaim(): UNCLAIM %pM on vid %d (sent by %pM)...\n",
claim_addr, BATADV_PRINT_VID(vid), backbone_gw->orig);
batadv_bla_del_claim(bat_priv, claim_addr, vid);
batadv_backbone_gw_put(backbone_gw);
return true;
}
/**
* batadv_handle_claim - check for CLAIM frame
* @bat_priv: the bat priv with all the soft interface information
* @primary_if: the primary hard interface of this batman soft interface
* @backbone_addr: originator address of the backbone (Ethernet Source)
* @claim_addr: client mac address to be claimed (ARP sender HW MAC)
* @vid: the VLAN ID of the frame
*
* Return: true if handled
*/
static bool batadv_handle_claim(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
u8 *backbone_addr, u8 *claim_addr,
unsigned short vid)
{
struct batadv_bla_backbone_gw *backbone_gw;
/* register the gateway if not yet available, and add the claim. */
backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid,
false);
if (unlikely(!backbone_gw))
return true;
/* this must be a CLAIM frame */
batadv_bla_add_claim(bat_priv, claim_addr, vid, backbone_gw);
if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
batadv_bla_send_claim(bat_priv, claim_addr, vid,
BATADV_CLAIM_TYPE_CLAIM);
/* TODO: we could call something like tt_local_del() here. */
batadv_backbone_gw_put(backbone_gw);
return true;
}
/**
* batadv_check_claim_group - check for claim group membership
* @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.
*
* Return:
* 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,
u8 *hw_src, u8 *hw_dst,
struct ethhdr *ethhdr)
{
u8 *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_put(orig_node);
return 2;
}
/**
* batadv_bla_process_claim - Check if this is a claim frame, and process it
* @bat_priv: the bat priv with all the soft interface information
* @primary_if: the primary hard interface of this batman soft interface
* @skb: the frame to be checked
*
* Return: true if it was a claim frame, otherwise return false to
* tell the callee that it can use the frame on its own.
*/
static bool batadv_bla_process_claim(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
struct sk_buff *skb)
{
struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
u8 *hw_src, *hw_dst;
struct vlan_hdr *vhdr, vhdr_buf;
struct ethhdr *ethhdr;
struct arphdr *arphdr;
unsigned short vid;
int vlan_depth = 0;
__be16 proto;
int headlen;
int ret;
vid = batadv_get_vid(skb, 0);
ethhdr = eth_hdr(skb);
proto = ethhdr->h_proto;
headlen = ETH_HLEN;
if (vid & BATADV_VLAN_HAS_TAG) {
/* Traverse the VLAN/Ethertypes.
*
* At this point it is known that the first protocol is a VLAN
* header, so start checking at the encapsulated protocol.
*
* The depth of the VLAN headers is recorded to drop BLA claim
* frames encapsulated into multiple VLAN headers (QinQ).
*/
do {
vhdr = skb_header_pointer(skb, headlen, VLAN_HLEN,
&vhdr_buf);
if (!vhdr)
return false;
proto = vhdr->h_vlan_encapsulated_proto;
headlen += VLAN_HLEN;
vlan_depth++;
} while (proto == htons(ETH_P_8021Q));
}
if (proto != htons(ETH_P_ARP))
return false; /* not a claim frame */
/* this must be a ARP frame. check if it is a claim. */
if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev))))
return false;
/* pskb_may_pull() may have modified the pointers, get ethhdr again */
ethhdr = eth_hdr(skb);
arphdr = (struct arphdr *)((u8 *)ethhdr + headlen);
/* Check whether the ARP frame carries a valid
* IP information
*/
if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
return false;
if (arphdr->ar_pro != htons(ETH_P_IP))
return false;
if (arphdr->ar_hln != ETH_ALEN)
return false;
if (arphdr->ar_pln != 4)
return false;
hw_src = (u8 *)arphdr + sizeof(struct arphdr);
hw_dst = hw_src + ETH_ALEN + 4;
bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
bla_dst_own = &bat_priv->bla.claim_dest;
/* check if it is a claim frame in general */
if (memcmp(bla_dst->magic, bla_dst_own->magic,
sizeof(bla_dst->magic)) != 0)
return false;
/* check if there is a claim frame encapsulated deeper in (QinQ) and
* drop that, as this is not supported by BLA but should also not be
* sent via the mesh.
*/
if (vlan_depth > 1)
return true;
/* Let the loopdetect frames on the mesh in any case. */
if (bla_dst->type == BATADV_CLAIM_TYPE_LOOPDETECT)
return 0;
/* check if it is a claim frame. */
ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst,
ethhdr);
if (ret == 1)
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_process_claim(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
ethhdr->h_source, BATADV_PRINT_VID(vid), hw_src,
hw_dst);
if (ret < 2)
return !!ret;
/* become a backbone gw ourselves on this vlan if not happened yet */
batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
/* check for the different types of claim frames ... */
switch (bla_dst->type) {
case BATADV_CLAIM_TYPE_CLAIM:
if (batadv_handle_claim(bat_priv, primary_if, hw_src,
ethhdr->h_source, vid))
return true;
break;
case BATADV_CLAIM_TYPE_UNCLAIM:
if (batadv_handle_unclaim(bat_priv, primary_if,
ethhdr->h_source, hw_src, vid))
return true;
break;
case BATADV_CLAIM_TYPE_ANNOUNCE:
if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source,
vid))
return true;
break;
case BATADV_CLAIM_TYPE_REQUEST:
if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr,
vid))
return true;
break;
}
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_process_claim(): ERROR - this looks like a claim frame, but is useless. eth src %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
ethhdr->h_source, BATADV_PRINT_VID(vid), hw_src, hw_dst);
return true;
}
/**
* batadv_bla_purge_backbone_gw - Remove backbone gateways after a timeout or
* immediately
* @bat_priv: the bat priv with all the soft interface information
* @now: whether the whole hash shall be wiped now
*
* Check when we last heard from other nodes, and remove them in case of
* a time out, or clean all backbone gws if now is set.
*/
static void batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now)
{
struct batadv_bla_backbone_gw *backbone_gw;
struct hlist_node *node_tmp;
struct hlist_head *head;
struct batadv_hashtable *hash;
spinlock_t *list_lock; /* protects write access to the hash lists */
int i;
hash = bat_priv->bla.backbone_hash;
if (!hash)
return;
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
list_lock = &hash->list_locks[i];
spin_lock_bh(list_lock);
hlist_for_each_entry_safe(backbone_gw, node_tmp,
head, hash_entry) {
if (now)
goto purge_now;
if (!batadv_has_timed_out(backbone_gw->lasttime,
BATADV_BLA_BACKBONE_TIMEOUT))
continue;
batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
"bla_purge_backbone_gw(): backbone gw %pM timed out\n",
backbone_gw->orig);
purge_now:
/* don't wait for the pending request anymore */
if (atomic_read(&backbone_gw->request_sent))
atomic_dec(&bat_priv->bla.num_requests);
batadv_bla_del_backbone_claims(backbone_gw);
hlist_del_rcu(&backbone_gw->hash_entry);
batadv_backbone_gw_put(backbone_gw);
}
spin_unlock_bh(list_lock);
}
}
/**
* batadv_bla_purge_claims - Remove claims after a timeout or immediately
* @bat_priv: the bat priv with all the soft interface information
* @primary_if: the selected primary interface, may be NULL if now is set
* @now: whether the whole hash shall be wiped now
*
* Check when we heard last time from our own claims, and remove them in case of
* a time out, or clean all claims if now is set
*/
static void batadv_bla_purge_claims(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
int now)
{
struct batadv_bla_claim *claim;
struct hlist_head *head;
struct batadv_hashtable *hash;
int i;
hash = bat_priv->bla.claim_hash;
if (!hash)
return;
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
rcu_read_lock();
hlist_for_each_entry_rcu(claim, head, hash_entry) {
if (now)
goto purge_now;
if (!batadv_compare_eth(claim->backbone_gw->orig,
primary_if->net_dev->dev_addr))
continue;
if (!batadv_has_timed_out(claim->lasttime,
BATADV_BLA_CLAIM_TIMEOUT))
continue;
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"bla_purge_claims(): %pM, vid %d, time out\n",
claim->addr, claim->vid);
purge_now:
batadv_handle_unclaim(bat_priv, primary_if,
claim->backbone_gw->orig,
claim->addr, claim->vid);
}
rcu_read_unlock();
}
}
/**
* batadv_bla_update_orig_address - Update the backbone gateways when the own
* originator address changes
* @bat_priv: the bat priv with all the soft interface information
* @primary_if: the new selected primary_if
* @oldif: the old primary interface, may be NULL
*/
void batadv_bla_update_orig_address(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
struct batadv_hard_iface *oldif)
{
struct batadv_bla_backbone_gw *backbone_gw;
struct hlist_head *head;
struct batadv_hashtable *hash;
__be16 group;
int i;
/* reset bridge loop avoidance group id */
group = htons(crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN));
bat_priv->bla.claim_dest.group = group;
/* purge everything when bridge loop avoidance is turned off */
if (!atomic_read(&bat_priv->bridge_loop_avoidance))
oldif = NULL;
if (!oldif) {
batadv_bla_purge_claims(bat_priv, NULL, 1);
batadv_bla_purge_backbone_gw(bat_priv, 1);
return;
}
hash = bat_priv->bla.backbone_hash;
if (!hash)
return;
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
rcu_read_lock();
hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
/* own orig still holds the old value. */
if (!batadv_compare_eth(backbone_gw->orig,
oldif->net_dev->dev_addr))
continue;
ether_addr_copy(backbone_gw->orig,
primary_if->net_dev->dev_addr);
/* send an announce frame so others will ask for our
* claims and update their tables.
*/
batadv_bla_send_announce(bat_priv, backbone_gw);
}
rcu_read_unlock();
}
}
/**
* batadv_bla_send_loopdetect - send a loopdetect frame
* @bat_priv: the bat priv with all the soft interface information
* @backbone_gw: the backbone gateway for which a loop should be detected
*
* To detect loops that the bridge loop avoidance can't handle, send a loop
* detection packet on the backbone. Unlike other BLA frames, this frame will
* be allowed on the mesh by other nodes. If it is received on the mesh, this
* indicates that there is a loop.
*/
static void
batadv_bla_send_loopdetect(struct batadv_priv *bat_priv,
struct batadv_bla_backbone_gw *backbone_gw)
{
batadv_dbg(BATADV_DBG_BLA, bat_priv, "Send loopdetect frame for vid %d\n",
backbone_gw->vid);
batadv_bla_send_claim(bat_priv, bat_priv->bla.loopdetect_addr,
backbone_gw->vid, BATADV_CLAIM_TYPE_LOOPDETECT);
}
/**
* batadv_bla_status_update - purge bla interfaces if necessary
* @net_dev: the soft interface net device
*/
void batadv_bla_status_update(struct net_device *net_dev)
{
struct batadv_priv *bat_priv = netdev_priv(net_dev);
struct batadv_hard_iface *primary_if;
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
return;
/* this function already purges everything when bla is disabled,
* so just call that one.
*/
batadv_bla_update_orig_address(bat_priv, primary_if, primary_if);
batadv_hardif_put(primary_if);
}
/**
* batadv_bla_periodic_work - performs periodic bla work
* @work: kernel work struct
*
* periodic work to do:
* * purge structures when they are too old
* * send announcements
*/
static void batadv_bla_periodic_work(struct work_struct *work)
{
struct delayed_work *delayed_work;
struct batadv_priv *bat_priv;
struct batadv_priv_bla *priv_bla;
struct hlist_head *head;
struct batadv_bla_backbone_gw *backbone_gw;
struct batadv_hashtable *hash;
struct batadv_hard_iface *primary_if;
bool send_loopdetect = false;
int i;
delayed_work = to_delayed_work(work);
priv_bla = container_of(delayed_work, struct batadv_priv_bla, work);
bat_priv = container_of(priv_bla, struct batadv_priv, bla);
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
batadv_bla_purge_claims(bat_priv, primary_if, 0);
batadv_bla_purge_backbone_gw(bat_priv, 0);
if (!atomic_read(&bat_priv->bridge_loop_avoidance))
goto out;
if (atomic_dec_and_test(&bat_priv->bla.loopdetect_next)) {
/* set a new random mac address for the next bridge loop
* detection frames. Set the locally administered bit to avoid
* collisions with users mac addresses.
*/
random_ether_addr(bat_priv->bla.loopdetect_addr);
bat_priv->bla.loopdetect_addr[0] = 0xba;
bat_priv->bla.loopdetect_addr[1] = 0xbe;
bat_priv->bla.loopdetect_lasttime = jiffies;
atomic_set(&bat_priv->bla.loopdetect_next,
BATADV_BLA_LOOPDETECT_PERIODS);
/* mark for sending loop detect on all VLANs */
send_loopdetect = true;
}
hash = bat_priv->bla.backbone_hash;
if (!hash)
goto out;
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
rcu_read_lock();
hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
if (!batadv_compare_eth(backbone_gw->orig,
primary_if->net_dev->dev_addr))
continue;
backbone_gw->lasttime = jiffies;
batadv_bla_send_announce(bat_priv, backbone_gw);
if (send_loopdetect)
batadv_bla_send_loopdetect(bat_priv,
backbone_gw);
/* request_sent is only set after creation to avoid
* problems when we are not yet known as backbone gw
* in the backbone.
*
* We can reset this now after we waited some periods
* to give bridge forward delays and bla group forming
* some grace time.
*/
if (atomic_read(&backbone_gw->request_sent) == 0)
continue;
if (!atomic_dec_and_test(&backbone_gw->wait_periods))
continue;
atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
atomic_set(&backbone_gw->request_sent, 0);
}
rcu_read_unlock();
}
out:
if (primary_if)
batadv_hardif_put(primary_if);
queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work,
msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
}
/* The hash for claim and backbone hash receive the same key because they
* are getting initialized by hash_new with the same key. Reinitializing
* them with to different keys to allow nested locking without generating
* lockdep warnings
*/
static struct lock_class_key batadv_claim_hash_lock_class_key;
static struct lock_class_key batadv_backbone_hash_lock_class_key;
/**
* batadv_bla_init - initialize all bla structures
* @bat_priv: the bat priv with all the soft interface information
*
* Return: 0 on success, < 0 on error.
*/
int batadv_bla_init(struct batadv_priv *bat_priv)
{
int i;
u8 claim_dest[ETH_ALEN] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00};
struct batadv_hard_iface *primary_if;
u16 crc;
unsigned long entrytime;
spin_lock_init(&bat_priv->bla.bcast_duplist_lock);
batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hash registering\n");
/* setting claim destination address */
memcpy(&bat_priv->bla.claim_dest.magic, claim_dest, 3);
bat_priv->bla.claim_dest.type = 0;
primary_if = batadv_primary_if_get_selected(bat_priv);
if (primary_if) {
crc = crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN);
bat_priv->bla.claim_dest.group = htons(crc);
batadv_hardif_put(primary_if);
} else {
bat_priv->bla.claim_dest.group = 0; /* will be set later */
}
/* initialize the duplicate list */
entrytime = jiffies - msecs_to_jiffies(BATADV_DUPLIST_TIMEOUT);
for (i = 0; i < BATADV_DUPLIST_SIZE; i++)
bat_priv->bla.bcast_duplist[i].entrytime = entrytime;
bat_priv->bla.bcast_duplist_curr = 0;
atomic_set(&bat_priv->bla.loopdetect_next,
BATADV_BLA_LOOPDETECT_PERIODS);
if (bat_priv->bla.claim_hash)
return 0;
bat_priv->bla.claim_hash = batadv_hash_new(128);
bat_priv->bla.backbone_hash = batadv_hash_new(32);
if (!bat_priv->bla.claim_hash || !bat_priv->bla.backbone_hash)
return -ENOMEM;
batadv_hash_set_lock_class(bat_priv->bla.claim_hash,
&batadv_claim_hash_lock_class_key);
batadv_hash_set_lock_class(bat_priv->bla.backbone_hash,
&batadv_backbone_hash_lock_class_key);
batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hashes initialized\n");
INIT_DELAYED_WORK(&bat_priv->bla.work, batadv_bla_periodic_work);
queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work,
msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
return 0;
}
/**
* batadv_bla_check_bcast_duplist - Check if a frame is in the broadcast dup.
* @bat_priv: the bat priv with all the soft interface information
* @skb: contains the bcast_packet to be checked
*
* check if it is on our broadcast list. Another gateway might
* have sent the same packet because it is connected to the same backbone,
* so we have to remove this duplicate.
*
* This is performed by checking the CRC, which will tell us
* with a good chance that it is the same packet. If it is furthermore
* sent by another host, drop it. We allow equal packets from
* the same host however as this might be intended.
*
* Return: true if a packet is in the duplicate list, false otherwise.
*/
bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
struct sk_buff *skb)
{
int i, curr;
__be32 crc;
struct batadv_bcast_packet *bcast_packet;
struct batadv_bcast_duplist_entry *entry;
bool ret = false;
bcast_packet = (struct batadv_bcast_packet *)skb->data;
/* calculate the crc ... */
crc = batadv_skb_crc32(skb, (u8 *)(bcast_packet + 1));
spin_lock_bh(&bat_priv->bla.bcast_duplist_lock);
for (i = 0; i < BATADV_DUPLIST_SIZE; i++) {
curr = (bat_priv->bla.bcast_duplist_curr + i);
curr %= BATADV_DUPLIST_SIZE;
entry = &bat_priv->bla.bcast_duplist[curr];
/* we can stop searching if the entry is too old ;
* later entries will be even older
*/
if (batadv_has_timed_out(entry->entrytime,
BATADV_DUPLIST_TIMEOUT))
break;
if (entry->crc != crc)
continue;
if (batadv_compare_eth(entry->orig, bcast_packet->orig))
continue;
/* this entry seems to match: same crc, not too old,
* and from another gw. therefore return true to forbid it.
*/
ret = true;
goto out;
}
/* not found, add a new entry (overwrite the oldest entry)
* and allow it, its the first occurrence.
*/
curr = (bat_priv->bla.bcast_duplist_curr + BATADV_DUPLIST_SIZE - 1);
curr %= BATADV_DUPLIST_SIZE;
entry = &bat_priv->bla.bcast_duplist[curr];
entry->crc = crc;
entry->entrytime = jiffies;
ether_addr_copy(entry->orig, bcast_packet->orig);
bat_priv->bla.bcast_duplist_curr = curr;
out:
spin_unlock_bh(&bat_priv->bla.bcast_duplist_lock);
return ret;
}
/**
* batadv_bla_is_backbone_gw_orig - Check if the originator is a gateway for
* the VLAN identified by vid.
* @bat_priv: the bat priv with all the soft interface information
* @orig: originator mac address
* @vid: VLAN identifier
*
* Return: true if orig is a backbone for this vid, false otherwise.
*/
bool batadv_bla_is_backbone_gw_orig(struct batadv_priv *bat_priv, u8 *orig,
unsigned short vid)
{
struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
struct hlist_head *head;
struct batadv_bla_backbone_gw *backbone_gw;
int i;
if (!atomic_read(&bat_priv->bridge_loop_avoidance))
return false;
if (!hash)
return false;
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
rcu_read_lock();
hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
if (batadv_compare_eth(backbone_gw->orig, orig) &&
backbone_gw->vid == vid) {
rcu_read_unlock();
return true;
}
}
rcu_read_unlock();
}
return false;
}
/**
* batadv_bla_is_backbone_gw - check if originator is a backbone gw for a VLAN.
* @skb: the frame to be checked
* @orig_node: the orig_node of the frame
* @hdr_size: maximum length of the frame
*
* Return: true if the orig_node is also a gateway on the soft interface,
* otherwise it returns false.
*/
bool batadv_bla_is_backbone_gw(struct sk_buff *skb,
struct batadv_orig_node *orig_node, int hdr_size)
{
struct batadv_bla_backbone_gw *backbone_gw;
unsigned short vid;
if (!atomic_read(&orig_node->bat_priv->bridge_loop_avoidance))
return false;
/* first, find out the vid. */
if (!pskb_may_pull(skb, hdr_size + ETH_HLEN))
return false;
vid = batadv_get_vid(skb, hdr_size);
/* see if this originator is a backbone gw for this VLAN */
backbone_gw = batadv_backbone_hash_find(orig_node->bat_priv,
orig_node->orig, vid);
if (!backbone_gw)
return false;
batadv_backbone_gw_put(backbone_gw);
return true;
}
/**
* batadv_bla_free - free all bla structures
* @bat_priv: the bat priv with all the soft interface information
*
* for softinterface free or module unload
*/
void batadv_bla_free(struct batadv_priv *bat_priv)
{
struct batadv_hard_iface *primary_if;
cancel_delayed_work_sync(&bat_priv->bla.work);
primary_if = batadv_primary_if_get_selected(bat_priv);
if (bat_priv->bla.claim_hash) {
batadv_bla_purge_claims(bat_priv, primary_if, 1);
batadv_hash_destroy(bat_priv->bla.claim_hash);
bat_priv->bla.claim_hash = NULL;
}
if (bat_priv->bla.backbone_hash) {
batadv_bla_purge_backbone_gw(bat_priv, 1);
batadv_hash_destroy(bat_priv->bla.backbone_hash);
bat_priv->bla.backbone_hash = NULL;
}
if (primary_if)
batadv_hardif_put(primary_if);
}
/**
* batadv_bla_loopdetect_check - check and handle a detected loop
* @bat_priv: the bat priv with all the soft interface information
* @skb: the packet to check
* @primary_if: interface where the request came on
* @vid: the VLAN ID of the frame
*
* Checks if this packet is a loop detect frame which has been sent by us,
* throw an uevent and log the event if that is the case.
*
* Return: true if it is a loop detect frame which is to be dropped, false
* otherwise.
*/
static bool
batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb,
struct batadv_hard_iface *primary_if,
unsigned short vid)
{
struct batadv_bla_backbone_gw *backbone_gw;
struct ethhdr *ethhdr;
ethhdr = eth_hdr(skb);
/* Only check for the MAC address and skip more checks here for
* performance reasons - this function is on the hotpath, after all.
*/
if (!batadv_compare_eth(ethhdr->h_source,
bat_priv->bla.loopdetect_addr))
return false;
/* If the packet came too late, don't forward it on the mesh
* but don't consider that as loop. It might be a coincidence.
*/
if (batadv_has_timed_out(bat_priv->bla.loopdetect_lasttime,
BATADV_BLA_LOOPDETECT_TIMEOUT))
return true;
backbone_gw = batadv_bla_get_backbone_gw(bat_priv,
primary_if->net_dev->dev_addr,
vid, true);
if (unlikely(!backbone_gw))
return true;
queue_work(batadv_event_workqueue, &backbone_gw->report_work);
/* backbone_gw is unreferenced in the report work function function */
return true;
}
/**
* batadv_bla_rx - check packets coming from the mesh.
* @bat_priv: the bat priv with all the soft interface information
* @skb: the frame to be checked
* @vid: the VLAN ID of the frame
* @is_bcast: the packet came in a broadcast packet type.
*
* batadv_bla_rx avoidance checks if:
* * we have to race for a claim
* * if the frame is allowed on the LAN
*
* in these cases, the skb is further handled by this function
*
* Return: true if handled, otherwise it returns false and the caller shall
* further process the skb.
*/
bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb,
unsigned short vid, bool is_bcast)
{
struct ethhdr *ethhdr;
struct batadv_bla_claim search_claim, *claim = NULL;
struct batadv_hard_iface *primary_if;
bool ret;
ethhdr = eth_hdr(skb);
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto handled;
if (!atomic_read(&bat_priv->bridge_loop_avoidance))
goto allow;
if (batadv_bla_loopdetect_check(bat_priv, skb, primary_if, vid))
goto handled;
if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
/* don't allow broadcasts while requests are in flight */
if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast)
goto handled;
ether_addr_copy(search_claim.addr, ethhdr->h_source);
search_claim.vid = vid;
claim = batadv_claim_hash_find(bat_priv, &search_claim);
if (!claim) {
/* possible optimization: race for a claim */
/* No claim exists yet, claim it for us!
*/
batadv_handle_claim(bat_priv, primary_if,
primary_if->net_dev->dev_addr,
ethhdr->h_source, vid);
goto allow;
}
/* if it is our own claim ... */
if (batadv_compare_eth(claim->backbone_gw->orig,
primary_if->net_dev->dev_addr)) {
/* ... allow it in any case */
claim->lasttime = jiffies;
goto allow;
}
/* if it is a broadcast ... */
if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) {
/* ... drop it. the responsible gateway is in charge.
*
* We need to check is_bcast because with the gateway
* feature, broadcasts (like DHCP requests) may be sent
* using a unicast packet type.
*/
goto handled;
} else {
/* seems the client considers us as its best gateway.
* send a claim and update the claim table
* immediately.
*/
batadv_handle_claim(bat_priv, primary_if,
primary_if->net_dev->dev_addr,
ethhdr->h_source, vid);
goto allow;
}
allow:
batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
ret = false;
goto out;
handled:
kfree_skb(skb);
ret = true;
out:
if (primary_if)
batadv_hardif_put(primary_if);
if (claim)
batadv_claim_put(claim);
return ret;
}
/**
* batadv_bla_tx - check packets going into the mesh
* @bat_priv: the bat priv with all the soft interface information
* @skb: the frame to be checked
* @vid: the VLAN ID of the frame
*
* batadv_bla_tx checks if:
* * a claim was received which has to be processed
* * the frame is allowed on the mesh
*
* in these cases, the skb is further handled by this function.
*
* This call might reallocate skb data.
*
* Return: true if handled, otherwise it returns false and the caller shall
* further process the skb.
*/
bool batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb,
unsigned short vid)
{
struct ethhdr *ethhdr;
struct batadv_bla_claim search_claim, *claim = NULL;
struct batadv_hard_iface *primary_if;
bool ret = false;
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
if (!atomic_read(&bat_priv->bridge_loop_avoidance))
goto allow;
if (batadv_bla_process_claim(bat_priv, primary_if, skb))
goto handled;
ethhdr = eth_hdr(skb);
if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
/* don't allow broadcasts while requests are in flight */
if (is_multicast_ether_addr(ethhdr->h_dest))
goto handled;
ether_addr_copy(search_claim.addr, ethhdr->h_source);
search_claim.vid = vid;
claim = batadv_claim_hash_find(bat_priv, &search_claim);
/* if no claim exists, allow it. */
if (!claim)
goto allow;
/* check if we are responsible. */
if (batadv_compare_eth(claim->backbone_gw->orig,
primary_if->net_dev->dev_addr)) {
/* if yes, the client has roamed and we have
* to unclaim it.
*/
batadv_handle_unclaim(bat_priv, primary_if,
primary_if->net_dev->dev_addr,
ethhdr->h_source, vid);
goto allow;
}
/* check if it is a multicast/broadcast frame */
if (is_multicast_ether_addr(ethhdr->h_dest)) {
/* drop it. the responsible gateway has forwarded it into
* the backbone network.
*/
goto handled;
} else {
/* we must allow it. at least if we are
* responsible for the DESTINATION.
*/
goto allow;
}
allow:
batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
ret = false;
goto out;
handled:
ret = true;
out:
if (primary_if)
batadv_hardif_put(primary_if);
if (claim)
batadv_claim_put(claim);
return ret;
}
/**
* batadv_bla_claim_table_seq_print_text - print the claim table in a seq file
* @seq: seq file to print on
* @offset: not used
*
* Return: always 0
*/
int batadv_bla_claim_table_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->bla.claim_hash;
struct batadv_bla_claim *claim;
struct batadv_hard_iface *primary_if;
struct hlist_head *head;
u16 backbone_crc;
u32 i;
bool is_own;
u8 *primary_addr;
primary_if = batadv_seq_print_text_primary_if_get(seq);
if (!primary_if)
goto out;
primary_addr = primary_if->net_dev->dev_addr;
seq_printf(seq,
"Claims announced for the mesh %s (orig %pM, group id %#.4x)\n",
net_dev->name, primary_addr,
ntohs(bat_priv->bla.claim_dest.group));
seq_puts(seq,
" Client VID Originator [o] (CRC )\n");
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
rcu_read_lock();
hlist_for_each_entry_rcu(claim, head, hash_entry) {
is_own = batadv_compare_eth(claim->backbone_gw->orig,
primary_addr);
spin_lock_bh(&claim->backbone_gw->crc_lock);
backbone_crc = claim->backbone_gw->crc;
spin_unlock_bh(&claim->backbone_gw->crc_lock);
seq_printf(seq, " * %pM on %5d by %pM [%c] (%#.4x)\n",
claim->addr, BATADV_PRINT_VID(claim->vid),
claim->backbone_gw->orig,
(is_own ? 'x' : ' '),
backbone_crc);
}
rcu_read_unlock();
}
out:
if (primary_if)
batadv_hardif_put(primary_if);
return 0;
}
/**
* batadv_bla_backbone_table_seq_print_text - print the backbone table in a seq
* file
* @seq: seq file to print on
* @offset: not used
*
* Return: always 0
*/
int batadv_bla_backbone_table_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->bla.backbone_hash;
struct batadv_bla_backbone_gw *backbone_gw;
struct batadv_hard_iface *primary_if;
struct hlist_head *head;
int secs, msecs;
u16 backbone_crc;
u32 i;
bool is_own;
u8 *primary_addr;
primary_if = batadv_seq_print_text_primary_if_get(seq);
if (!primary_if)
goto out;
primary_addr = primary_if->net_dev->dev_addr;
seq_printf(seq,
"Backbones announced for the mesh %s (orig %pM, group id %#.4x)\n",
net_dev->name, primary_addr,
ntohs(bat_priv->bla.claim_dest.group));
seq_puts(seq, " Originator VID last seen (CRC )\n");
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
rcu_read_lock();
hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
msecs = jiffies_to_msecs(jiffies -
backbone_gw->lasttime);
secs = msecs / 1000;
msecs = msecs % 1000;
is_own = batadv_compare_eth(backbone_gw->orig,
primary_addr);
if (is_own)
continue;
spin_lock_bh(&backbone_gw->crc_lock);
backbone_crc = backbone_gw->crc;
spin_unlock_bh(&backbone_gw->crc_lock);
seq_printf(seq, " * %pM on %5d %4i.%03is (%#.4x)\n",
backbone_gw->orig,
BATADV_PRINT_VID(backbone_gw->vid), secs,
msecs, backbone_crc);
}
rcu_read_unlock();
}
out:
if (primary_if)
batadv_hardif_put(primary_if);
return 0;
}
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