Beispiel #1
0
/* 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;
}
Beispiel #5
0
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;
}