linux/net/batman-adv/bridge_loop_avoidance.c
Linus Lüssing 9d2c9488ce batman-adv: fix potential kernel paging errors for unicast transmissions
There are several functions which might reallocate skb data. Currently
some places keep reusing their old ethhdr pointer regardless of whether
they became invalid after such a reallocation or not. This potentially
leads to kernel paging errors.

This patch fixes these by refetching the ethdr pointer after the
potential reallocations.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-08-10 22:55:42 +02:00

1705 lines
47 KiB
C

/* Copyright (C) 2011-2013 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*/
#include "main.h"
#include "hash.h"
#include "hard-interface.h"
#include "originator.h"
#include "bridge_loop_avoidance.h"
#include "translation-table.h"
#include "send.h"
#include <linux/etherdevice.h>
#include <linux/crc16.h>
#include <linux/if_arp.h>
#include <net/arp.h>
#include <linux/if_vlan.h>
static const uint8_t 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);
/* return the index of the claim */
static inline uint32_t batadv_choose_claim(const void *data, uint32_t size)
{
struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data;
uint32_t hash = 0;
hash = batadv_hash_bytes(hash, &claim->addr, sizeof(claim->addr));
hash = batadv_hash_bytes(hash, &claim->vid, sizeof(claim->vid));
hash += (hash << 3);
hash ^= (hash >> 11);
hash += (hash << 15);
return hash % size;
}
/* return the index of the backbone gateway */
static inline uint32_t batadv_choose_backbone_gw(const void *data,
uint32_t size)
{
const struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data;
uint32_t hash = 0;
hash = batadv_hash_bytes(hash, &claim->addr, sizeof(claim->addr));
hash = batadv_hash_bytes(hash, &claim->vid, sizeof(claim->vid));
hash += (hash << 3);
hash ^= (hash >> 11);
hash += (hash << 15);
return hash % size;
}
/* compares address and vid of two backbone gws */
static int 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, *gw2 = data2;
if (!batadv_compare_eth(gw1->orig, gw2->orig))
return 0;
if (gw1->vid != gw2->vid)
return 0;
return 1;
}
/* compares address and vid of two claims */
static int 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, *cl2 = data2;
if (!batadv_compare_eth(cl1->addr, cl2->addr))
return 0;
if (cl1->vid != cl2->vid)
return 0;
return 1;
}
/* free a backbone gw */
static void
batadv_backbone_gw_free_ref(struct batadv_bla_backbone_gw *backbone_gw)
{
if (atomic_dec_and_test(&backbone_gw->refcount))
kfree_rcu(backbone_gw, rcu);
}
/* finally deinitialize the claim */
static void batadv_claim_free_rcu(struct rcu_head *rcu)
{
struct batadv_bla_claim *claim;
claim = container_of(rcu, struct batadv_bla_claim, rcu);
batadv_backbone_gw_free_ref(claim->backbone_gw);
kfree(claim);
}
/* free a claim, call claim_free_rcu if its the last reference */
static void batadv_claim_free_ref(struct batadv_bla_claim *claim)
{
if (atomic_dec_and_test(&claim->refcount))
call_rcu(&claim->rcu, batadv_claim_free_rcu);
}
/* @bat_priv: the bat priv with all the soft interface information
* @data: search data (may be local/static data)
*
* looks for a claim in the hash, and returns it 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 (!atomic_inc_not_zero(&claim->refcount))
continue;
claim_tmp = claim;
break;
}
rcu_read_unlock();
return claim_tmp;
}
/**
* batadv_backbone_hash_find - looks for a claim in the hash
* @bat_priv: the bat priv with all the soft interface information
* @addr: the address of the originator
* @vid: the VLAN ID
*
* Returns claim if found or NULL otherwise.
*/
static struct batadv_bla_backbone_gw *
batadv_backbone_hash_find(struct batadv_priv *bat_priv,
uint8_t *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;
memcpy(search_entry.orig, addr, ETH_ALEN);
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 (!atomic_inc_not_zero(&backbone_gw->refcount))
continue;
backbone_gw_tmp = backbone_gw;
break;
}
rcu_read_unlock();
return backbone_gw_tmp;
}
/* delete all claims for a backbone */
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_free_ref(claim);
hlist_del_rcu(&claim->hash_entry);
}
spin_unlock_bh(list_lock);
}
/* all claims gone, intialize CRC */
backbone_gw->crc = BATADV_BLA_CRC_INIT;
}
/**
* batadv_bla_send_claim - sends a claim frame according to the provided info
* @bat_priv: the bat priv with all the soft interface information
* @orig: 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, uint8_t *mac,
unsigned short vid, int claimtype)
{
struct sk_buff *skb;
struct ethhdr *ethhdr;
struct batadv_hard_iface *primary_if;
struct net_device *soft_iface;
uint8_t *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
*/
(uint8_t *)&local_claim_dest);
if (!skb)
goto out;
ethhdr = (struct ethhdr *)skb->data;
hw_src = (uint8_t *)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
*/
memcpy(ethhdr->h_source, mac, ETH_ALEN);
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
*/
memcpy(hw_src, mac, ETH_ALEN);
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
*/
memcpy(hw_src, mac, ETH_ALEN);
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
*/
memcpy(hw_src, mac, ETH_ALEN);
memcpy(ethhdr->h_dest, mac, ETH_ALEN);
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;
}
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_free_ref(primary_if);
}
/**
* 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_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);
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);
}
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;
}
/* 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_free_ref(backbone_gw);
}
/* @bat_priv: the bat priv with all the soft interface information
* @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_free_ref(backbone_gw);
}
/* @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);
}
}
/* @bat_priv: the bat priv with all the soft interface information
* @backbone_gw: our backbone gateway which should be announced
*
* This function sends an announcement. It is called from multiple
* places.
*/
static void batadv_bla_send_announce(struct batadv_priv *bat_priv,
struct batadv_bla_backbone_gw *backbone_gw)
{
uint8_t mac[ETH_ALEN];
__be16 crc;
memcpy(mac, batadv_announce_mac, 4);
crc = htons(backbone_gw->crc);
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 uint8_t *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;
memcpy(search_claim.addr, mac, ETH_ALEN);
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;
memcpy(claim->addr, mac, ETH_ALEN);
claim->vid = vid;
claim->lasttime = jiffies;
claim->backbone_gw = backbone_gw;
atomic_set(&claim->refcount, 2);
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));
claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
batadv_backbone_gw_free_ref(claim->backbone_gw);
}
/* set (new) backbone gw */
atomic_inc(&backbone_gw->refcount);
claim->backbone_gw = backbone_gw;
backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
backbone_gw->lasttime = jiffies;
claim_free_ref:
batadv_claim_free_ref(claim);
}
/* Delete a claim from the claim hash which has the
* given mac address and vid.
*/
static void batadv_bla_del_claim(struct batadv_priv *bat_priv,
const uint8_t *mac, const unsigned short vid)
{
struct batadv_bla_claim search_claim, *claim;
memcpy(search_claim.addr, mac, ETH_ALEN);
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_free_ref(claim); /* reference from the hash is gone */
claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
/* don't need the reference from hash_find() anymore */
batadv_claim_free_ref(claim);
}
/* check for ANNOUNCE frame, return 1 if handled */
static int batadv_handle_announce(struct batadv_priv *bat_priv,
uint8_t *an_addr, uint8_t *backbone_addr,
unsigned short vid)
{
struct batadv_bla_backbone_gw *backbone_gw;
uint16_t crc;
if (memcmp(an_addr, batadv_announce_mac, 4) != 0)
return 0;
backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid,
false);
if (unlikely(!backbone_gw))
return 1;
/* 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);
if (backbone_gw->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_gw->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_free_ref(backbone_gw);
return 1;
}
/* check for REQUEST frame, return 1 if handled */
static int batadv_handle_request(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
uint8_t *backbone_addr,
struct ethhdr *ethhdr, unsigned short vid)
{
/* check for REQUEST frame */
if (!batadv_compare_eth(backbone_addr, ethhdr->h_dest))
return 0;
/* 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 1;
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 1;
}
/* check for UNCLAIM frame, return 1 if handled */
static int batadv_handle_unclaim(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
uint8_t *backbone_addr,
uint8_t *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 1;
/* 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_free_ref(backbone_gw);
return 1;
}
/* check for CLAIM frame, return 1 if handled */
static int batadv_handle_claim(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
uint8_t *backbone_addr, uint8_t *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 1;
/* 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_free_ref(backbone_gw);
return 1;
}
/**
* batadv_check_claim_group
* @bat_priv: the bat priv with all the soft interface information
* @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;
/* check if it is a claim packet in general */
if (memcmp(bla_dst->magic, bla_dst_own->magic,
sizeof(bla_dst->magic)) != 0)
return 0;
/* 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;
}
/* @bat_priv: the bat priv with all the soft interface information
* @skb: the frame to be checked
*
* Check if this is a claim frame, and process it accordingly.
*
* returns 1 if it was a claim frame, otherwise return 0 to
* tell the callee that it can use the frame on its own.
*/
static int batadv_bla_process_claim(struct batadv_priv *bat_priv,
struct batadv_hard_iface *primary_if,
struct sk_buff *skb)
{
struct ethhdr *ethhdr;
struct vlan_ethhdr *vhdr;
struct arphdr *arphdr;
uint8_t *hw_src, *hw_dst;
struct batadv_bla_claim_dst *bla_dst;
uint16_t proto;
int headlen;
unsigned short vid = BATADV_NO_FLAGS;
int ret;
ethhdr = eth_hdr(skb);
if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
vhdr = (struct vlan_ethhdr *)ethhdr;
vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
vid |= BATADV_VLAN_HAS_TAG;
proto = ntohs(vhdr->h_vlan_encapsulated_proto);
headlen = sizeof(*vhdr);
} else {
proto = ntohs(ethhdr->h_proto);
headlen = ETH_HLEN;
}
if (proto != ETH_P_ARP)
return 0; /* 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 0;
/* pskb_may_pull() may have modified the pointers, get ethhdr again */
ethhdr = eth_hdr(skb);
arphdr = (struct arphdr *)((uint8_t *)ethhdr + headlen);
/* Check whether the ARP frame carries a valid
* IP information
*/
if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
return 0;
if (arphdr->ar_pro != htons(ETH_P_IP))
return 0;
if (arphdr->ar_hln != ETH_ALEN)
return 0;
if (arphdr->ar_pln != 4)
return 0;
hw_src = (uint8_t *)arphdr + sizeof(struct arphdr);
hw_dst = hw_src + ETH_ALEN + 4;
bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
/* 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 1;
break;
case BATADV_CLAIM_TYPE_UNCLAIM:
if (batadv_handle_unclaim(bat_priv, primary_if,
ethhdr->h_source, hw_src, vid))
return 1;
break;
case BATADV_CLAIM_TYPE_ANNOUNCE:
if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source,
vid))
return 1;
break;
case BATADV_CLAIM_TYPE_REQUEST:
if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr,
vid))
return 1;
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 1;
}
/* 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_free_ref(backbone_gw);
}
spin_unlock_bh(list_lock);
}
}
/**
* batadv_bla_purge_claims
* @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
* @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
*
* Update the backbone gateways when the own orig address changes.
*/
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;
memcpy(backbone_gw->orig,
primary_if->net_dev->dev_addr, ETH_ALEN);
/* 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();
}
}
/* 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;
int i;
delayed_work = container_of(work, struct 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;
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);
/* 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_free_ref(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;
/* initialize all bla structures */
int batadv_bla_init(struct batadv_priv *bat_priv)
{
int i;
uint8_t claim_dest[ETH_ALEN] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00};
struct batadv_hard_iface *primary_if;
uint16_t 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_free_ref(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;
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
* @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.
*/
int batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
struct sk_buff *skb)
{
int i, curr, ret = 0;
__be32 crc;
struct batadv_bcast_packet *bcast_packet;
struct batadv_bcast_duplist_entry *entry;
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 1 to forbid it.
*/
ret = 1;
goto out;
}
/* not found, add a new entry (overwrite the oldest entry)
* and allow it, its the first occurence.
*/
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;
memcpy(entry->orig, bcast_packet->orig, ETH_ALEN);
bat_priv->bla.bcast_duplist_curr = curr;
out:
spin_unlock_bh(&bat_priv->bla.bcast_duplist_lock);
return ret;
}
/* @bat_priv: the bat priv with all the soft interface information
* @orig: originator mac address
*
* check if the originator is a gateway for any VLAN ID.
*
* returns 1 if it is found, 0 otherwise
*/
int batadv_bla_is_backbone_gw_orig(struct batadv_priv *bat_priv, uint8_t *orig)
{
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 0;
if (!hash)
return 0;
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)) {
rcu_read_unlock();
return 1;
}
}
rcu_read_unlock();
}
return 0;
}
/**
* batadv_bla_is_backbone_gw
* @skb: the frame to be checked
* @orig_node: the orig_node of the frame
* @hdr_size: maximum length of the frame
*
* bla_is_backbone_gw inspects the skb for the VLAN ID and returns 1
* if the orig_node is also a gateway on the soft interface, otherwise it
* returns 0.
*/
int batadv_bla_is_backbone_gw(struct sk_buff *skb,
struct batadv_orig_node *orig_node, int hdr_size)
{
struct ethhdr *ethhdr;
struct vlan_ethhdr *vhdr;
struct batadv_bla_backbone_gw *backbone_gw;
unsigned short vid = BATADV_NO_FLAGS;
if (!atomic_read(&orig_node->bat_priv->bridge_loop_avoidance))
return 0;
/* first, find out the vid. */
if (!pskb_may_pull(skb, hdr_size + ETH_HLEN))
return 0;
ethhdr = (struct ethhdr *)(((uint8_t *)skb->data) + hdr_size);
if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
if (!pskb_may_pull(skb, hdr_size + sizeof(struct vlan_ethhdr)))
return 0;
vhdr = (struct vlan_ethhdr *)(skb->data + hdr_size);
vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
vid |= BATADV_VLAN_HAS_TAG;
}
/* 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 0;
batadv_backbone_gw_free_ref(backbone_gw);
return 1;
}
/* free all bla structures (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_free_ref(primary_if);
}
/**
* batadv_bla_rx
* @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.
*
* 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 and
* returns 1, otherwise it returns 0 and the caller shall further
* process the skb.
*/
int 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;
int 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 (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;
memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN);
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 = 0;
goto out;
handled:
kfree_skb(skb);
ret = 1;
out:
if (primary_if)
batadv_hardif_free_ref(primary_if);
if (claim)
batadv_claim_free_ref(claim);
return ret;
}
/**
* batadv_bla_tx
* @bat_priv: the bat priv with all the soft interface information
* @skb: the frame to be checked
* @vid: the VLAN ID of the frame
*
* 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 and
* returns 1, otherwise it returns 0 and the caller shall further
* process the skb.
*
* This call might reallocate skb data.
*/
int 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;
int ret = 0;
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
if (!atomic_read(&bat_priv->bridge_loop_avoidance))
goto allow;
/* in VLAN case, the mac header might not be set. */
skb_reset_mac_header(skb);
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;
memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN);
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 = 0;
goto out;
handled:
ret = 1;
out:
if (primary_if)
batadv_hardif_free_ref(primary_if);
if (claim)
batadv_claim_free_ref(claim);
return ret;
}
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;
uint32_t i;
bool is_own;
uint8_t *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_printf(seq, " %-17s %-5s %-17s [o] (%-6s)\n",
"Client", "VID", "Originator", "CRC");
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);
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' : ' '),
claim->backbone_gw->crc);
}
rcu_read_unlock();
}
out:
if (primary_if)
batadv_hardif_free_ref(primary_if);
return 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;
uint32_t i;
bool is_own;
uint8_t *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_printf(seq, " %-17s %-5s %-9s (%-6s)\n",
"Originator", "VID", "last seen", "CRC");
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;
seq_printf(seq, " * %pM on %5d %4i.%03is (%#.4x)\n",
backbone_gw->orig,
BATADV_PRINT_VID(backbone_gw->vid), secs,
msecs, backbone_gw->crc);
}
rcu_read_unlock();
}
out:
if (primary_if)
batadv_hardif_free_ref(primary_if);
return 0;
}