text: /* Copyright (C) 2007-2014 B.A.T.M.A.N. contributors:
   *
   * Marek Lindner, 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 <linux/crc32c.h>
  #include <linux/highmem.h>
  #include <linux/if_vlan.h>
  #include <net/ip.h>
  #include <net/ipv6.h>
  #include <net/dsfield.h>
  #include "main.h"
  #include "sysfs.h"
  #include "debugfs.h"
  #include "routing.h"
  #include "send.h"
  #include "originator.h"
  #include "soft-interface.h"
  #include "icmp_socket.h"
  #include "translation-table.h"
  #include "hard-interface.h"
  #include "gateway_client.h"
  #include "bridge_loop_avoidance.h"
  #include "distributed-arp-table.h"
  #include "gateway_common.h"
  #include "hash.h"
  #include "bat_algo.h"
  #include "network-coding.h"
  #include "fragmentation.h"
  
  
  /* List manipulations on hardif_list have to be rtnl_lock()'ed,
   * list traversals just rcu-locked
   */
  struct list_head batadv_hardif_list;
  static int (*batadv_rx_handler[256])(struct sk_buff *,
  				     struct batadv_hard_iface *);
  char batadv_routing_algo[20] = "BATMAN_IV";
  static struct hlist_head batadv_algo_list;
  
  unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
  
  struct workqueue_struct *batadv_event_workqueue;
  
  static void batadv_recv_handler_init(void);
  
  static int __init batadv_init(void)
  {
  	INIT_LIST_HEAD(&batadv_hardif_list);
  	INIT_HLIST_HEAD(&batadv_algo_list);
  
  	batadv_recv_handler_init();
  
  	batadv_iv_init();
  	batadv_nc_init();
  
  	batadv_event_workqueue = create_singlethread_workqueue("bat_events");
  
  	if (!batadv_event_workqueue)
  		return -ENOMEM;
  
  	batadv_socket_init();
  	batadv_debugfs_init();
  
  	register_netdevice_notifier(&batadv_hard_if_notifier);
  	rtnl_link_register(&batadv_link_ops);
  
  	pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
  		BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
  
  	return 0;
  }
  
  static void __exit batadv_exit(void)
  {
  	batadv_debugfs_destroy();
  	rtnl_link_unregister(&batadv_link_ops);
  	unregister_netdevice_notifier(&batadv_hard_if_notifier);
  	batadv_hardif_remove_interfaces();
  
  	flush_workqueue(batadv_event_workqueue);
  	destroy_workqueue(batadv_event_workqueue);
  	batadv_event_workqueue = NULL;
  
  	rcu_barrier();
  }
  
  int batadv_mesh_init(struct net_device *soft_iface)
  {
  	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
  	int ret;
  
  	spin_lock_init(&bat_priv->forw_bat_list_lock);
  	spin_lock_init(&bat_priv->forw_bcast_list_lock);
  	spin_lock_init(&bat_priv->tt.changes_list_lock);
  	spin_lock_init(&bat_priv->tt.req_list_lock);
  	spin_lock_init(&bat_priv->tt.roam_list_lock);
  	spin_lock_init(&bat_priv->tt.last_changeset_lock);
  	spin_lock_init(&bat_priv->tt.commit_lock);
  	spin_lock_init(&bat_priv->gw.list_lock);
  	spin_lock_init(&bat_priv->tvlv.container_list_lock);
  	spin_lock_init(&bat_priv->tvlv.handler_list_lock);
  	spin_lock_init(&bat_priv->softif_vlan_list_lock);
  
  	INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
  	INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
  	INIT_HLIST_HEAD(&bat_priv->gw.list);
  	INIT_LIST_HEAD(&bat_priv->tt.changes_list);
  	INIT_LIST_HEAD(&bat_priv->tt.req_list);
  	INIT_LIST_HEAD(&bat_priv->tt.roam_list);
  	INIT_HLIST_HEAD(&bat_priv->tvlv.container_list);
  	INIT_HLIST_HEAD(&bat_priv->tvlv.handler_list);
  	INIT_HLIST_HEAD(&bat_priv->softif_vlan_list);
  
  	ret = batadv_originator_init(bat_priv);
  	if (ret < 0)
  		goto err;
  
  	ret = batadv_tt_init(bat_priv);
  	if (ret < 0)
  		goto err;
  
  	ret = batadv_bla_init(bat_priv);
  	if (ret < 0)
  		goto err;
  
  	ret = batadv_dat_init(bat_priv);
  	if (ret < 0)
  		goto err;
  
  	ret = batadv_nc_mesh_init(bat_priv);
  	if (ret < 0)
  		goto err;
  
  	batadv_gw_init(bat_priv);
  
  	atomic_set(&bat_priv->gw.reselect, 0);
  	atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
  
  	return 0;
  
  err:
  	batadv_mesh_free(soft_iface);
  	return ret;
  }
  
  void batadv_mesh_free(struct net_device *soft_iface)
  {
  	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
  
  	atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
  
  	batadv_purge_outstanding_packets(bat_priv, NULL);
  
  	batadv_gw_node_purge(bat_priv);
  	batadv_nc_mesh_free(bat_priv);
  	batadv_dat_free(bat_priv);
  	batadv_bla_free(bat_priv);
  
  	/* Free the TT and the originator tables only after having terminated
  	 * all the other depending components which may use these structures for
  	 * their purposes.
  	 */
  	batadv_tt_free(bat_priv);
  
  	/* Since the originator table clean up routine is accessing the TT
  	 * tables as well, it has to be invoked after the TT tables have been
  	 * freed and marked as empty. This ensures that no cleanup RCU callbacks
  	 * accessing the TT data are scheduled for later execution.
  	 */
  	batadv_originator_free(bat_priv);
  
  	batadv_gw_free(bat_priv);
  
  	free_percpu(bat_priv->bat_counters);
  	bat_priv->bat_counters = NULL;
  
  	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
  }
  
  /**
   * batadv_is_my_mac - check if the given mac address belongs to any of the real
   * interfaces in the current mesh
   * @bat_priv: the bat priv with all the soft interface information
   * @addr: the address to check
   */
  int batadv_is_my_mac(struct batadv_priv *bat_priv, const uint8_t *addr)
  {
  	const struct batadv_hard_iface *hard_iface;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  		if (hard_iface->if_status != BATADV_IF_ACTIVE)
  			continue;
  
  		if (hard_iface->soft_iface != bat_priv->soft_iface)
  			continue;
  
  		if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
  			rcu_read_unlock();
  			return 1;
  		}
  	}
  	rcu_read_unlock();
  	return 0;
  }
  
  /**
   * batadv_seq_print_text_primary_if_get - called from debugfs table printing
   *  function that requires the primary interface
   * @seq: debugfs table seq_file struct
   *
   * Returns primary interface if found or NULL otherwise.
   */
  struct batadv_hard_iface *
  batadv_seq_print_text_primary_if_get(struct seq_file *seq)
  {
  	struct net_device *net_dev = (struct net_device *)seq->private;
  	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) {
  		seq_printf(seq,
  			   "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
  			   net_dev->name);
  		goto out;
  	}
  
  	if (primary_if->if_status == BATADV_IF_ACTIVE)
  		goto out;
  
  	seq_printf(seq,
  		   "BATMAN mesh %s disabled - primary interface not active\n",
  		   net_dev->name);
  	batadv_hardif_free_ref(primary_if);
  	primary_if = NULL;
  
  out:
  	return primary_if;
  }
  
  /**
   * batadv_max_header_len - calculate maximum encapsulation overhead for a
   *  payload packet
   *
   * Return the maximum encapsulation overhead in bytes.
   */
  int batadv_max_header_len(void)
  {
  	int header_len = 0;
  
  	header_len = max_t(int, header_len,
  			   sizeof(struct batadv_unicast_packet));
  	header_len = max_t(int, header_len,
  			   sizeof(struct batadv_unicast_4addr_packet));
  	header_len = max_t(int, header_len,
  			   sizeof(struct batadv_bcast_packet));
  
  #ifdef CONFIG_BATMAN_ADV_NC
  	header_len = max_t(int, header_len,
  			   sizeof(struct batadv_coded_packet));
  #endif
  
  	return header_len + ETH_HLEN;
  }
  
  /**
   * batadv_skb_set_priority - sets skb priority according to packet content
   * @skb: the packet to be sent
   * @offset: offset to the packet content
   *
   * This function sets a value between 256 and 263 (802.1d priority), which
   * can be interpreted by the cfg80211 or other drivers.
   */
  void batadv_skb_set_priority(struct sk_buff *skb, int offset)
  {
  	struct iphdr ip_hdr_tmp, *ip_hdr;
  	struct ipv6hdr ip6_hdr_tmp, *ip6_hdr;
  	struct ethhdr ethhdr_tmp, *ethhdr;
  	struct vlan_ethhdr *vhdr, vhdr_tmp;
  	u32 prio;
  
  	/* already set, do nothing */
  	if (skb->priority >= 256 && skb->priority <= 263)
  		return;
  
  	ethhdr = skb_header_pointer(skb, offset, sizeof(*ethhdr), &ethhdr_tmp);
  	if (!ethhdr)
  		return;
  
  	switch (ethhdr->h_proto) {
  	case htons(ETH_P_8021Q):
  		vhdr = skb_header_pointer(skb, offset + sizeof(*vhdr),
  					  sizeof(*vhdr), &vhdr_tmp);
  		if (!vhdr)
  			return;
  		prio = ntohs(vhdr->h_vlan_TCI) & VLAN_PRIO_MASK;
  		prio = prio >> VLAN_PRIO_SHIFT;
  		break;
  	case htons(ETH_P_IP):
  		ip_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
  					    sizeof(*ip_hdr), &ip_hdr_tmp);
  		if (!ip_hdr)
  			return;
  		prio = (ipv4_get_dsfield(ip_hdr) & 0xfc) >> 5;
  		break;
  	case htons(ETH_P_IPV6):
  		ip6_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
  					     sizeof(*ip6_hdr), &ip6_hdr_tmp);
  		if (!ip6_hdr)
  			return;
  		prio = (ipv6_get_dsfield(ip6_hdr) & 0xfc) >> 5;
  		break;
  	default:
  		return;
  	}
  
  	skb->priority = prio + 256;
  }
  
  static int batadv_recv_unhandled_packet(struct sk_buff *skb,
  					struct batadv_hard_iface *recv_if)
  {
  	return NET_RX_DROP;
  }
  
  /* incoming packets with the batman ethertype received on any active hard
   * interface
   */
  int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
  			   struct packet_type *ptype,
  			   struct net_device *orig_dev)
  {
  	struct batadv_priv *bat_priv;
  	struct batadv_ogm_packet *batadv_ogm_packet;
  	struct batadv_hard_iface *hard_iface;
  	uint8_t idx;
  	int ret;
  
  	hard_iface = container_of(ptype, struct batadv_hard_iface,
  				  batman_adv_ptype);
  	skb = skb_share_check(skb, GFP_ATOMIC);
  
  	/* skb was released by skb_share_check() */
  	if (!skb)
  		goto err_out;
  
  	/* packet should hold at least type and version */
  	if (unlikely(!pskb_may_pull(skb, 2)))
  		goto err_free;
  
  	/* expect a valid ethernet header here. */
  	if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
  		goto err_free;
  
  	if (!hard_iface->soft_iface)
  		goto err_free;
  
  	bat_priv = netdev_priv(hard_iface->soft_iface);
  
  	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
  		goto err_free;
  
  	/* discard frames on not active interfaces */
  	if (hard_iface->if_status != BATADV_IF_ACTIVE)
  		goto err_free;
  
  	batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
  
  	if (batadv_ogm_packet->version != BATADV_COMPAT_VERSION) {
  		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
  			   "Drop packet: incompatible batman version (%i)\n",
  			   batadv_ogm_packet->version);
  		goto err_free;
  	}
  
  	/* all receive handlers return whether they received or reused
  	 * the supplied skb. if not, we have to free the skb.
  	 */
  	idx = batadv_ogm_packet->packet_type;
  	ret = (*batadv_rx_handler[idx])(skb, hard_iface);
  
  	if (ret == NET_RX_DROP)
  		kfree_skb(skb);
  
  	/* return NET_RX_SUCCESS in any case as we
  	 * most probably dropped the packet for
  	 * routing-logical reasons.
  	 */
  	return NET_RX_SUCCESS;
  
  err_free:
  	kfree_skb(skb);
  err_out:
  	return NET_RX_DROP;
  }
  
  static void batadv_recv_handler_init(void)
  {
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
  		batadv_rx_handler[i] = batadv_recv_unhandled_packet;
  
  	for (i = BATADV_UNICAST_MIN; i <= BATADV_UNICAST_MAX; i++)
  		batadv_rx_handler[i] = batadv_recv_unhandled_unicast_packet;
  
  	/* compile time checks for sizes */
  	BUILD_BUG_ON(sizeof(struct batadv_bla_claim_dst) != 6);
  	BUILD_BUG_ON(sizeof(struct batadv_ogm_packet) != 24);
  	BUILD_BUG_ON(sizeof(struct batadv_icmp_header) != 20);
  	BUILD_BUG_ON(sizeof(struct batadv_icmp_packet) != 20);
  	BUILD_BUG_ON(sizeof(struct batadv_icmp_packet_rr) != 116);
  	BUILD_BUG_ON(sizeof(struct batadv_unicast_packet) != 10);
  	BUILD_BUG_ON(sizeof(struct batadv_unicast_4addr_packet) != 18);
  	BUILD_BUG_ON(sizeof(struct batadv_frag_packet) != 20);
  	BUILD_BUG_ON(sizeof(struct batadv_bcast_packet) != 14);
  	BUILD_BUG_ON(sizeof(struct batadv_coded_packet) != 46);
  	BUILD_BUG_ON(sizeof(struct batadv_unicast_tvlv_packet) != 20);
  	BUILD_BUG_ON(sizeof(struct batadv_tvlv_hdr) != 4);
  	BUILD_BUG_ON(sizeof(struct batadv_tvlv_gateway_data) != 8);
  	BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_vlan_data) != 8);
  	BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_change) != 12);
  	BUILD_BUG_ON(sizeof(struct batadv_tvlv_roam_adv) != 8);
  
  	/* broadcast packet */
  	batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
  
  	/* unicast packets ... */
  	/* unicast with 4 addresses packet */
  	batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
  	/* unicast packet */
  	batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
  	/* unicast tvlv packet */
  	batadv_rx_handler[BATADV_UNICAST_TVLV] = batadv_recv_unicast_tvlv;
  	/* batman icmp packet */
  	batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
  	/* Fragmented packets */
  	batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_frag_packet;
  }
  
  int
  batadv_recv_handler_register(uint8_t packet_type,
  			     int (*recv_handler)(struct sk_buff *,
  						 struct batadv_hard_iface *))
  {
  	int (*curr)(struct sk_buff *,
  		    struct batadv_hard_iface *);
  	curr = batadv_rx_handler[packet_type];
  
  	if ((curr != batadv_recv_unhandled_packet) &&
  	    (curr != batadv_recv_unhandled_unicast_packet))
  		return -EBUSY;
  
  	batadv_rx_handler[packet_type] = recv_handler;
  	return 0;
  }
  
  void batadv_recv_handler_unregister(uint8_t packet_type)
  {
  	batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
  }
  
  static struct batadv_algo_ops *batadv_algo_get(char *name)
  {
  	struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
  
  	hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
  		if (strcmp(bat_algo_ops_tmp->name, name) != 0)
  			continue;
  
  		bat_algo_ops = bat_algo_ops_tmp;
  		break;
  	}
  
  	return bat_algo_ops;
  }
  
  int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
  {
  	struct batadv_algo_ops *bat_algo_ops_tmp;
  	int ret;
  
  	bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
  	if (bat_algo_ops_tmp) {
  		pr_info("Trying to register already registered routing algorithm: %s\n",
  			bat_algo_ops->name);
  		ret = -EEXIST;
  		goto out;
  	}
  
  	/* all algorithms must implement all ops (for now) */
  	if (!bat_algo_ops->bat_iface_enable ||
  	    !bat_algo_ops->bat_iface_disable ||
  	    !bat_algo_ops->bat_iface_update_mac ||
  	    !bat_algo_ops->bat_primary_iface_set ||
  	    !bat_algo_ops->bat_ogm_schedule ||
  	    !bat_algo_ops->bat_ogm_emit ||
  	    !bat_algo_ops->bat_neigh_cmp ||
  	    !bat_algo_ops->bat_neigh_is_equiv_or_better) {
  		pr_info("Routing algo '%s' does not implement required ops\n",
  			bat_algo_ops->name);
  		ret = -EINVAL;
  		goto out;
  	}
  
  	INIT_HLIST_NODE(&bat_algo_ops->list);
  	hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
  	ret = 0;
  
  out:
  	return ret;
  }
  
  int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
  {
  	struct batadv_algo_ops *bat_algo_ops;
  	int ret = -EINVAL;
  
  	bat_algo_ops = batadv_algo_get(name);
  	if (!bat_algo_ops)
  		goto out;
  
  	bat_priv->bat_algo_ops = bat_algo_ops;
  	ret = 0;
  
  out:
  	return ret;
  }
  
  int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
  {
  	struct batadv_algo_ops *bat_algo_ops;
  
  	seq_puts(seq, "Available routing algorithms:\n");
  
  	hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
  		seq_printf(seq, "%s\n", bat_algo_ops->name);
  	}
  
  	return 0;
  }
  
  /**
   * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
   *  the header
   * @skb: skb pointing to fragmented socket buffers
   * @payload_ptr: Pointer to position inside the head buffer of the skb
   *  marking the start of the data to be CRC'ed
   *
   * payload_ptr must always point to an address in the skb head buffer and not to
   * a fragment.
   */
  __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
  {
  	u32 crc = 0;
  	unsigned int from;
  	unsigned int to = skb->len;
  	struct skb_seq_state st;
  	const u8 *data;
  	unsigned int len;
  	unsigned int consumed = 0;
  
  	from = (unsigned int)(payload_ptr - skb->data);
  
  	skb_prepare_seq_read(skb, from, to, &st);
  	while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
  		crc = crc32c(crc, data, len);
  		consumed += len;
  	}
  
  	return htonl(crc);
  }
  
  /**
   * batadv_tvlv_handler_free_ref - decrement the tvlv handler refcounter and
   *  possibly free it
   * @tvlv_handler: the tvlv handler to free
   */
  static void
  batadv_tvlv_handler_free_ref(struct batadv_tvlv_handler *tvlv_handler)
  {
  	if (atomic_dec_and_test(&tvlv_handler->refcount))
  		kfree_rcu(tvlv_handler, rcu);
  }
  
  /**
   * batadv_tvlv_handler_get - retrieve tvlv handler from the tvlv handler list
   *  based on the provided type and version (both need to match)
   * @bat_priv: the bat priv with all the soft interface information
   * @type: tvlv handler type to look for
   * @version: tvlv handler version to look for
   *
   * Returns tvlv handler if found or NULL otherwise.
   */
  static struct batadv_tvlv_handler
  *batadv_tvlv_handler_get(struct batadv_priv *bat_priv,
  			 uint8_t type, uint8_t version)
  {
  	struct batadv_tvlv_handler *tvlv_handler_tmp, *tvlv_handler = NULL;
  
  	rcu_read_lock();
  	hlist_for_each_entry_rcu(tvlv_handler_tmp,
  				 &bat_priv->tvlv.handler_list, list) {
  		if (tvlv_handler_tmp->type != type)
  			continue;
  
  		if (tvlv_handler_tmp->version != version)
  			continue;
  
  		if (!atomic_inc_not_zero(&tvlv_handler_tmp->refcount))
  			continue;
  
  		tvlv_handler = tvlv_handler_tmp;
  		break;
  	}
  	rcu_read_unlock();
  
  	return tvlv_handler;
  }
  
  /**
   * batadv_tvlv_container_free_ref - decrement the tvlv container refcounter and
   *  possibly free it
   * @tvlv_handler: the tvlv container to free
   */
  static void batadv_tvlv_container_free_ref(struct batadv_tvlv_container *tvlv)
  {
  	if (atomic_dec_and_test(&tvlv->refcount))
  		kfree(tvlv);
  }
  
  /**
   * batadv_tvlv_container_get - retrieve tvlv container from the tvlv container
   *  list based on the provided type and version (both need to match)
   * @bat_priv: the bat priv with all the soft interface information
   * @type: tvlv container type to look for
   * @version: tvlv container version to look for
   *
   * Has to be called with the appropriate locks being acquired
   * (tvlv.container_list_lock).
   *
   * Returns tvlv container if found or NULL otherwise.
   */
  static struct batadv_tvlv_container
  *batadv_tvlv_container_get(struct batadv_priv *bat_priv,
  			   uint8_t type, uint8_t version)
  {
  	struct batadv_tvlv_container *tvlv_tmp, *tvlv = NULL;
  
  	hlist_for_each_entry(tvlv_tmp, &bat_priv->tvlv.container_list, list) {
  		if (tvlv_tmp->tvlv_hdr.type != type)
  			continue;
  
  		if (tvlv_tmp->tvlv_hdr.version != version)
  			continue;
  
  		if (!atomic_inc_not_zero(&tvlv_tmp->refcount))
  			continue;
  
  		tvlv = tvlv_tmp;
  		break;
  	}
  
  	return tvlv;
  }
  
  /**
   * batadv_tvlv_container_list_size - calculate the size of the tvlv container
   *  list entries
   * @bat_priv: the bat priv with all the soft interface information
   *
   * Has to be called with the appropriate locks being acquired
   * (tvlv.container_list_lock).
   *
   * Returns size of all currently registered tvlv containers in bytes.
   */
  static uint16_t batadv_tvlv_container_list_size(struct batadv_priv *bat_priv)
  {
  	struct batadv_tvlv_container *tvlv;
  	uint16_t tvlv_len = 0;
  
  	hlist_for_each_entry(tvlv, &bat_priv->tvlv.container_list, list) {
  		tvlv_len += sizeof(struct batadv_tvlv_hdr);
  		tvlv_len += ntohs(tvlv->tvlv_hdr.len);
  	}
  
  	return tvlv_len;
  }
  
  /**
   * batadv_tvlv_container_remove - remove tvlv container from the tvlv container
   *  list
   * @tvlv: the to be removed tvlv container
   *
   * Has to be called with the appropriate locks being acquired
   * (tvlv.container_list_lock).
   */
  static void batadv_tvlv_container_remove(struct batadv_tvlv_container *tvlv)
  {
  	if (!tvlv)
  		return;
  
  	hlist_del(&tvlv->list);
  
  	/* first call to decrement the counter, second call to free */
  	batadv_tvlv_container_free_ref(tvlv);
  	batadv_tvlv_container_free_ref(tvlv);
  }
  
  /**
   * batadv_tvlv_container_unregister - unregister tvlv container based on the
   *  provided type and version (both need to match)
   * @bat_priv: the bat priv with all the soft interface information
   * @type: tvlv container type to unregister
   * @version: tvlv container type to unregister
   */
  void batadv_tvlv_container_unregister(struct batadv_priv *bat_priv,
  				      uint8_t type, uint8_t version)
  {
  	struct batadv_tvlv_container *tvlv;
  
  	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
  	tvlv = batadv_tvlv_container_get(bat_priv, type, version);
  	batadv_tvlv_container_remove(tvlv);
  	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
  }
  
  /**
   * batadv_tvlv_container_register - register tvlv type, version and content
   *  to be propagated with each (primary interface) OGM
   * @bat_priv: the bat priv with all the soft interface information
   * @type: tvlv container type
   * @version: tvlv container version
   * @tvlv_value: tvlv container content
   * @tvlv_value_len: tvlv container content length
   *
   * If a container of the same type and version was already registered the new
   * content is going to replace the old one.
   */
  void batadv_tvlv_container_register(struct batadv_priv *bat_priv,
  				    uint8_t type, uint8_t version,
  				    void *tvlv_value, uint16_t tvlv_value_len)
  {
  	struct batadv_tvlv_container *tvlv_old, *tvlv_new;
  
  	if (!tvlv_value)
  		tvlv_value_len = 0;
  
  	tvlv_new = kzalloc(sizeof(*tvlv_new) + tvlv_value_len, GFP_ATOMIC);
  	if (!tvlv_new)
  		return;
  
  	tvlv_new->tvlv_hdr.version = version;
  	tvlv_new->tvlv_hdr.type = type;
  	tvlv_new->tvlv_hdr.len = htons(tvlv_value_len);
  
  	memcpy(tvlv_new + 1, tvlv_value, ntohs(tvlv_new->tvlv_hdr.len));
  	INIT_HLIST_NODE(&tvlv_new->list);
  	atomic_set(&tvlv_new->refcount, 1);
  
  	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
  	tvlv_old = batadv_tvlv_container_get(bat_priv, type, version);
  	batadv_tvlv_container_remove(tvlv_old);
  	hlist_add_head(&tvlv_new->list, &bat_priv->tvlv.container_list);
  	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
  }
  
  /**
   * batadv_tvlv_realloc_packet_buff - reallocate packet buffer to accomodate
   *  requested packet size
   * @packet_buff: packet buffer
   * @packet_buff_len: packet buffer size
   * @packet_min_len: requested packet minimum size
   * @additional_packet_len: requested additional packet size on top of minimum
   *  size
   *
   * Returns true of the packet buffer could be changed to the requested size,
   * false otherwise.
   */
  static bool batadv_tvlv_realloc_packet_buff(unsigned char **packet_buff,
  					    int *packet_buff_len,
  					    int min_packet_len,
  					    int additional_packet_len)
  {
  	unsigned char *new_buff;
  
  	new_buff = kmalloc(min_packet_len + additional_packet_len, GFP_ATOMIC);
  
  	/* keep old buffer if kmalloc should fail */
  	if (new_buff) {
  		memcpy(new_buff, *packet_buff, min_packet_len);
  		kfree(*packet_buff);
  		*packet_buff = new_buff;
  		*packet_buff_len = min_packet_len + additional_packet_len;
  		return true;
  	}
  
  	return false;
  }
  
  /**
   * batadv_tvlv_container_ogm_append - append tvlv container content to given
   *  OGM packet buffer
   * @bat_priv: the bat priv with all the soft interface information
   * @packet_buff: ogm packet buffer
   * @packet_buff_len: ogm packet buffer size including ogm header and tvlv
   *  content
   * @packet_min_len: ogm header size to be preserved for the OGM itself
   *
   * The ogm packet might be enlarged or shrunk depending on the current size
   * and the size of the to-be-appended tvlv containers.
   *
   * Returns size of all appended tvlv containers in bytes.
   */
  uint16_t batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv,
  					  unsigned char **packet_buff,
  					  int *packet_buff_len,
  					  int packet_min_len)
  {
  	struct batadv_tvlv_container *tvlv;
  	struct batadv_tvlv_hdr *tvlv_hdr;
  	uint16_t tvlv_value_len;
  	void *tvlv_value;
  	bool ret;
  
  	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
  	tvlv_value_len = batadv_tvlv_container_list_size(bat_priv);
  
  	ret = batadv_tvlv_realloc_packet_buff(packet_buff, packet_buff_len,
  					      packet_min_len, tvlv_value_len);
  
  	if (!ret)
  		goto end;
  
  	if (!tvlv_value_len)
  		goto end;
  
  	tvlv_value = (*packet_buff) + packet_min_len;
  
  	hlist_for_each_entry(tvlv, &bat_priv->tvlv.container_list, list) {
  		tvlv_hdr = tvlv_value;
  		tvlv_hdr->type = tvlv->tvlv_hdr.type;
  		tvlv_hdr->version = tvlv->tvlv_hdr.version;
  		tvlv_hdr->len = tvlv->tvlv_hdr.len;
  		tvlv_value = tvlv_hdr + 1;
  		memcpy(tvlv_value, tvlv + 1, ntohs(tvlv->tvlv_hdr.len));
  		tvlv_value = (uint8_t *)tvlv_value + ntohs(tvlv->tvlv_hdr.len);
  	}
  
  end:
  	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
  	return tvlv_value_len;
  }
  
  /**
   * batadv_tvlv_call_handler - parse the given tvlv buffer to call the
   *  appropriate handlers
   * @bat_priv: the bat priv with all the soft interface information
   * @tvlv_handler: tvlv callback function handling the tvlv content
   * @ogm_source: flag indicating wether the tvlv is an ogm or a unicast packet
   * @orig_node: orig node emitting the ogm packet
   * @src: source mac address of the unicast packet
   * @dst: destination mac address of the unicast packet
   * @tvlv_value: tvlv content
   * @tvlv_value_len: tvlv content length
   *
   * Returns success if handler was not found or the return value of the handler
   * callback.
   */
  static int batadv_tvlv_call_handler(struct batadv_priv *bat_priv,
  				    struct batadv_tvlv_handler *tvlv_handler,
  				    bool ogm_source,
  				    struct batadv_orig_node *orig_node,
  				    uint8_t *src, uint8_t *dst,
  				    void *tvlv_value, uint16_t tvlv_value_len)
  {
  	if (!tvlv_handler)
  		return NET_RX_SUCCESS;
  
  	if (ogm_source) {
  		if (!tvlv_handler->ogm_handler)
  			return NET_RX_SUCCESS;
  
  		if (!orig_node)
  			return NET_RX_SUCCESS;
  
  		tvlv_handler->ogm_handler(bat_priv, orig_node,
  					  BATADV_NO_FLAGS,
  					  tvlv_value, tvlv_value_len);
  		tvlv_handler->flags |= BATADV_TVLV_HANDLER_OGM_CALLED;
  	} else {
  		if (!src)
  			return NET_RX_SUCCESS;
  
  		if (!dst)
  			return NET_RX_SUCCESS;
  
  		if (!tvlv_handler->unicast_handler)
  			return NET_RX_SUCCESS;
  
  		return tvlv_handler->unicast_handler(bat_priv, src,
  						     dst, tvlv_value,
  						     tvlv_value_len);
  	}
  
  	return NET_RX_SUCCESS;
  }
  
  /**
   * batadv_tvlv_containers_process - parse the given tvlv buffer to call the
   *  appropriate handlers
   * @bat_priv: the bat priv with all the soft interface information
   * @ogm_source: flag indicating wether the tvlv is an ogm or a unicast packet
   * @orig_node: orig node emitting the ogm packet
   * @src: source mac address of the unicast packet
   * @dst: destination mac address of the unicast packet
   * @tvlv_value: tvlv content
   * @tvlv_value_len: tvlv content length
   *
   * Returns success when processing an OGM or the return value of all called
   * handler callbacks.
   */
  int batadv_tvlv_containers_process(struct batadv_priv *bat_priv,
  				   bool ogm_source,
  				   struct batadv_orig_node *orig_node,
  				   uint8_t *src, uint8_t *dst,
  				   void *tvlv_value, uint16_t tvlv_value_len)
  {
  	struct batadv_tvlv_handler *tvlv_handler;
  	struct batadv_tvlv_hdr *tvlv_hdr;
  	uint16_t tvlv_value_cont_len;
  	uint8_t cifnotfound = BATADV_TVLV_HANDLER_OGM_CIFNOTFND;
  	int ret = NET_RX_SUCCESS;
  
  	while (tvlv_value_len >= sizeof(*tvlv_hdr)) {
  		tvlv_hdr = tvlv_value;
  		tvlv_value_cont_len = ntohs(tvlv_hdr->len);
  		tvlv_value = tvlv_hdr + 1;
  		tvlv_value_len -= sizeof(*tvlv_hdr);
  
  		if (tvlv_value_cont_len > tvlv_value_len)
  			break;
  
  		tvlv_handler = batadv_tvlv_handler_get(bat_priv,
  						       tvlv_hdr->type,
  						       tvlv_hdr->version);
  
  		ret |= batadv_tvlv_call_handler(bat_priv, tvlv_handler,
  						ogm_source, orig_node,
  						src, dst, tvlv_value,
  						tvlv_value_cont_len);
  		if (tvlv_handler)
  			batadv_tvlv_handler_free_ref(tvlv_handler);
  		tvlv_value = (uint8_t *)tvlv_value + tvlv_value_cont_len;
  		tvlv_value_len -= tvlv_value_cont_len;
  	}
  
  	if (!ogm_source)
  		return ret;
  
  	rcu_read_lock();
  	hlist_for_each_entry_rcu(tvlv_handler,
  				 &bat_priv->tvlv.handler_list, list) {
  		if ((tvlv_handler->flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) &&
  		    !(tvlv_handler->flags & BATADV_TVLV_HANDLER_OGM_CALLED))
  			tvlv_handler->ogm_handler(bat_priv, orig_node,
  						  cifnotfound, NULL, 0);
  
  		tvlv_handler->flags &= ~BATADV_TVLV_HANDLER_OGM_CALLED;
  	}
  	rcu_read_unlock();
  
  	return NET_RX_SUCCESS;
  }
  
  /**
   * batadv_tvlv_ogm_receive - process an incoming ogm and call the appropriate
   *  handlers
   * @bat_priv: the bat priv with all the soft interface information
   * @batadv_ogm_packet: ogm packet containing the tvlv containers
   * @orig_node: orig node emitting the ogm packet
   */
  void batadv_tvlv_ogm_receive(struct batadv_priv *bat_priv,
  			     struct batadv_ogm_packet *batadv_ogm_packet,
  			     struct batadv_orig_node *orig_node)
  {
  	void *tvlv_value;
  	uint16_t tvlv_value_len;
  
  	if (!batadv_ogm_packet)
  		return;
  
  	tvlv_value_len = ntohs(batadv_ogm_packet->tvlv_len);
  	if (!tvlv_value_len)
  		return;
  
  	tvlv_value = batadv_ogm_packet + 1;
  
  	batadv_tvlv_containers_process(bat_priv, true, orig_node, NULL, NULL,
  				       tvlv_value, tvlv_value_len);
  }
  
  /**
   * batadv_tvlv_handler_register - register tvlv handler based on the provided
   *  type and version (both need to match) for ogm tvlv payload and/or unicast
   *  payload
   * @bat_priv: the bat priv with all the soft interface information
   * @optr: ogm tvlv handler callback function. This function receives the orig
   *  node, flags and the tvlv content as argument to process.
   * @uptr: unicast tvlv handler callback function. This function receives the
   *  source & destination of the unicast packet as well as the tvlv content
   *  to process.
   * @type: tvlv handler type to be registered
   * @version: tvlv handler version to be registered
   * @flags: flags to enable or disable TVLV API behavior
   */
  void batadv_tvlv_handler_register(struct batadv_priv *bat_priv,
  				  void (*optr)(struct batadv_priv *bat_priv,
  					       struct batadv_orig_node *orig,
  					       uint8_t flags,
  					       void *tvlv_value,
  					       uint16_t tvlv_value_len),
  				  int (*uptr)(struct batadv_priv *bat_priv,
  					      uint8_t *src, uint8_t *dst,
  					      void *tvlv_value,
  					      uint16_t tvlv_value_len),
  				  uint8_t type, uint8_t version, uint8_t flags)
  {
  	struct batadv_tvlv_handler *tvlv_handler;
  
  	tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
  	if (tvlv_handler) {
  		batadv_tvlv_handler_free_ref(tvlv_handler);
  		return;
  	}
  
  	tvlv_handler = kzalloc(sizeof(*tvlv_handler), GFP_ATOMIC);
  	if (!tvlv_handler)
  		return;
  
  	tvlv_handler->ogm_handler = optr;
  	tvlv_handler->unicast_handler = uptr;
  	tvlv_handler->type = type;
  	tvlv_handler->version = version;
  	tvlv_handler->flags = flags;
  	atomic_set(&tvlv_handler->refcount, 1);
  	INIT_HLIST_NODE(&tvlv_handler->list);
  
  	spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
  	hlist_add_head_rcu(&tvlv_handler->list, &bat_priv->tvlv.handler_list);
  	spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
  }
  
  /**
   * batadv_tvlv_handler_unregister - unregister tvlv handler based on the
   *  provided type and version (both need to match)
   * @bat_priv: the bat priv with all the soft interface information
   * @type: tvlv handler type to be unregistered
   * @version: tvlv handler version to be unregistered
   */
  void batadv_tvlv_handler_unregister(struct batadv_priv *bat_priv,
  				    uint8_t type, uint8_t version)
  {
  	struct batadv_tvlv_handler *tvlv_handler;
  
  	tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
  	if (!tvlv_handler)
  		return;
  
  	batadv_tvlv_handler_free_ref(tvlv_handler);
  	spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
  	hlist_del_rcu(&tvlv_handler->list);
  	spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
  	batadv_tvlv_handler_free_ref(tvlv_handler);
  }
  
  /**
   * batadv_tvlv_unicast_send - send a unicast packet with tvlv payload to the
   *  specified host
   * @bat_priv: the bat priv with all the soft interface information
   * @src: source mac address of the unicast packet
   * @dst: destination mac address of the unicast packet
   * @type: tvlv type
   * @version: tvlv version
   * @tvlv_value: tvlv content
   * @tvlv_value_len: tvlv content length
   */
  void batadv_tvlv_unicast_send(struct batadv_priv *bat_priv, uint8_t *src,
  			      uint8_t *dst, uint8_t type, uint8_t version,
  			      void *tvlv_value, uint16_t tvlv_value_len)
  {
  	struct batadv_unicast_tvlv_packet *unicast_tvlv_packet;
  	struct batadv_tvlv_hdr *tvlv_hdr;
  	struct batadv_orig_node *orig_node;
  	struct sk_buff *skb = NULL;
  	unsigned char *tvlv_buff;
  	unsigned int tvlv_len;
  	ssize_t hdr_len = sizeof(*unicast_tvlv_packet);
  	bool ret = false;
  
  	orig_node = batadv_orig_hash_find(bat_priv, dst);
  	if (!orig_node)
  		goto out;
  
  	tvlv_len = sizeof(*tvlv_hdr) + tvlv_value_len;
  
  	skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + hdr_len + tvlv_len);
  	if (!skb)
  		goto out;
  
  	skb->priority = TC_PRIO_CONTROL;
  	skb_reserve(skb, ETH_HLEN);
  	tvlv_buff = skb_put(skb, sizeof(*unicast_tvlv_packet) + tvlv_len);
  	unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)tvlv_buff;
  	unicast_tvlv_packet->packet_type = BATADV_UNICAST_TVLV;
  	unicast_tvlv_packet->version = BATADV_COMPAT_VERSION;
  	unicast_tvlv_packet->ttl = BATADV_TTL;
  	unicast_tvlv_packet->reserved = 0;
  	unicast_tvlv_packet->tvlv_len = htons(tvlv_len);
  	unicast_tvlv_packet->align = 0;
  	memcpy(unicast_tvlv_packet->src, src, ETH_ALEN);
  	memcpy(unicast_tvlv_packet->dst, dst, ETH_ALEN);
  
  	tvlv_buff = (unsigned char *)(unicast_tvlv_packet + 1);
  	tvlv_hdr = (struct batadv_tvlv_hdr *)tvlv_buff;
  	tvlv_hdr->version = version;
  	tvlv_hdr->type = type;
  	tvlv_hdr->len = htons(tvlv_value_len);
  	tvlv_buff += sizeof(*tvlv_hdr);
  	memcpy(tvlv_buff, tvlv_value, tvlv_value_len);
  
  	if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
  		ret = true;
  
  out:
  	if (skb && !ret)
  		kfree_skb(skb);
  	if (orig_node)
  		batadv_orig_node_free_ref(orig_node);
  }
  
  /**
   * batadv_get_vid - extract the VLAN identifier from skb if any
   * @skb: the buffer containing the packet
   * @header_len: length of the batman header preceding the ethernet header
   *
   * If the packet embedded in the skb is vlan tagged this function returns the
   * VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS is returned.
   */
  unsigned short batadv_get_vid(struct sk_buff *skb, size_t header_len)
  {
  	struct ethhdr *ethhdr = (struct ethhdr *)(skb->data + header_len);
  	struct vlan_ethhdr *vhdr;
  	unsigned short vid;
  
  	if (ethhdr->h_proto != htons(ETH_P_8021Q))
  		return BATADV_NO_FLAGS;
  
  	if (!pskb_may_pull(skb, header_len + VLAN_ETH_HLEN))
  		return BATADV_NO_FLAGS;
  
  	vhdr = (struct vlan_ethhdr *)(skb->data + header_len);
  	vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
  	vid |= BATADV_VLAN_HAS_TAG;
  
  	return vid;
  }
  
  /**
   * batadv_vlan_ap_isola_get - return the AP isolation status for the given vlan
   * @bat_priv: the bat priv with all the soft interface information
   * @vid: the VLAN identifier for which the AP isolation attributed as to be
   *  looked up
   *
   * Returns true if AP isolation is on for the VLAN idenfied by vid, false
   * otherwise
   */
  bool batadv_vlan_ap_isola_get(struct batadv_priv *bat_priv, unsigned short vid)
  {
  	bool ap_isolation_enabled = false;
  	struct batadv_softif_vlan *vlan;
  
  	/* if the AP isolation is requested on a VLAN, then check for its
  	 * setting in the proper VLAN private data structure
  	 */
  	vlan = batadv_softif_vlan_get(bat_priv, vid);
  	if (vlan) {
  		ap_isolation_enabled = atomic_read(&vlan->ap_isolation);
  		batadv_softif_vlan_free_ref(vlan);
  	}
  
  	return ap_isolation_enabled;
  }
  
  static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
  {
  	struct batadv_algo_ops *bat_algo_ops;
  	char *algo_name = (char *)val;
  	size_t name_len = strlen(algo_name);
  
  	if (name_len > 0 && algo_name[name_len - 1] == '\n')
  		algo_name[name_len - 1] = '\0';
  
  	bat_algo_ops = batadv_algo_get(algo_name);
  	if (!bat_algo_ops) {
  		pr_err("Routing algorithm '%s' is not supported\n", algo_name);
  		return -EINVAL;
  	}
  
  	return param_set_copystring(algo_name, kp);
  }
  
  static const struct kernel_param_ops batadv_param_ops_ra = {
  	.set = batadv_param_set_ra,
  	.get = param_get_string,
  };
  
  static struct kparam_string batadv_param_string_ra = {
  	.maxlen = sizeof(batadv_routing_algo),
  	.string = batadv_routing_algo,
  };
  
  module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
  		0644);
  module_init(batadv_init);
  module_exit(batadv_exit);
  
  MODULE_LICENSE("GPL");
  
  MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
  MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
  MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
  MODULE_VERSION(BATADV_SOURCE_VERSION);
  