/* 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));
}
/**
* 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;
}
/**
* 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, 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 = (struct ethhdr *)skb_mac_header(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.
*/
int batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb, 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 = (struct ethhdr *)skb_mac_header(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;
}
static int batadv_interface_tx(struct sk_buff *skb,
struct net_device *soft_iface)
{
struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
struct batadv_priv *bat_priv = netdev_priv(soft_iface);
struct batadv_hard_iface *primary_if = NULL;
struct batadv_bcast_packet *bcast_packet;
struct vlan_ethhdr *vhdr;
__be16 ethertype = __constant_htons(ETH_P_BATMAN);
static const uint8_t stp_addr[ETH_ALEN] = {0x01, 0x80, 0xC2, 0x00,
0x00, 0x00};
static const uint8_t ectp_addr[ETH_ALEN] = {0xCF, 0x00, 0x00, 0x00,
0x00, 0x00};
unsigned int header_len = 0;
int data_len = skb->len, ret;
short vid __maybe_unused = -1;
bool do_bcast = false;
uint32_t seqno;
unsigned long brd_delay = 1;
if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
goto dropped;
soft_iface->trans_start = jiffies;
switch (ntohs(ethhdr->h_proto)) {
case ETH_P_8021Q:
vhdr = (struct vlan_ethhdr *)skb->data;
vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
if (vhdr->h_vlan_encapsulated_proto != ethertype)
break;
/* fall through */
case ETH_P_BATMAN:
goto dropped;
}
if (batadv_bla_tx(bat_priv, skb, vid))
goto dropped;
/* Register the client MAC in the transtable */
if (!is_multicast_ether_addr(ethhdr->h_source))
batadv_tt_local_add(soft_iface, ethhdr->h_source, skb->skb_iif);
/* don't accept stp packets. STP does not help in meshes.
* better use the bridge loop avoidance ...
*
* The same goes for ECTP sent at least by some Cisco Switches,
* it might confuse the mesh when used with bridge loop avoidance.
*/
if (batadv_compare_eth(ethhdr->h_dest, stp_addr))
goto dropped;
if (batadv_compare_eth(ethhdr->h_dest, ectp_addr))
goto dropped;
if (is_multicast_ether_addr(ethhdr->h_dest)) {
do_bcast = true;
switch (atomic_read(&bat_priv->gw_mode)) {
case BATADV_GW_MODE_SERVER:
/* gateway servers should not send dhcp
* requests into the mesh
*/
ret = batadv_gw_is_dhcp_target(skb, &header_len);
if (ret)
goto dropped;
break;
case BATADV_GW_MODE_CLIENT:
/* gateway clients should send dhcp requests
* via unicast to their gateway
*/
ret = batadv_gw_is_dhcp_target(skb, &header_len);
if (ret)
do_bcast = false;
break;
case BATADV_GW_MODE_OFF:
default:
break;
}
}
/* ethernet packet should be broadcasted */
if (do_bcast) {
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto dropped;
/* in case of ARP request, we do not immediately broadcasti the
* packet, instead we first wait for DAT to try to retrieve the
* correct ARP entry
*/
if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb))
brd_delay = msecs_to_jiffies(ARP_REQ_DELAY);
if (batadv_skb_head_push(skb, sizeof(*bcast_packet)) < 0)
goto dropped;
bcast_packet = (struct batadv_bcast_packet *)skb->data;
bcast_packet->header.version = BATADV_COMPAT_VERSION;
bcast_packet->header.ttl = BATADV_TTL;
/* batman packet type: broadcast */
bcast_packet->header.packet_type = BATADV_BCAST;
bcast_packet->reserved = 0;
/* hw address of first interface is the orig mac because only
* this mac is known throughout the mesh
*/
memcpy(bcast_packet->orig,
primary_if->net_dev->dev_addr, ETH_ALEN);
/* set broadcast sequence number */
seqno = atomic_inc_return(&bat_priv->bcast_seqno);
bcast_packet->seqno = htonl(seqno);
batadv_add_bcast_packet_to_list(bat_priv, skb, brd_delay);
/* a copy is stored in the bcast list, therefore removing
* the original skb.
*/
kfree_skb(skb);
/* unicast packet */
} else {
if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_OFF) {
ret = batadv_gw_out_of_range(bat_priv, skb, ethhdr);
if (ret)
goto dropped;
}
if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb))
goto dropped;
batadv_dat_snoop_outgoing_arp_reply(bat_priv, skb);
ret = batadv_unicast_send_skb(bat_priv, skb);
if (ret != 0)
goto dropped_freed;
}
batadv_inc_counter(bat_priv, BATADV_CNT_TX);
batadv_add_counter(bat_priv, BATADV_CNT_TX_BYTES, data_len);
goto end;
dropped:
kfree_skb(skb);
dropped_freed:
batadv_inc_counter(bat_priv, BATADV_CNT_TX_DROPPED);
end:
if (primary_if)
batadv_hardif_free_ref(primary_if);
return NETDEV_TX_OK;
}