net/batman-adv/send.c - kernel/msm-4.19 - Gitiles

 /* Copyright (C) 2007-2013 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 "main.h"
 #include "distributed-arp-table.h"
 #include "send.h"
 #include "routing.h"
 #include "translation-table.h"
 #include "soft-interface.h"
 #include "hard-interface.h"
 #include "gateway_common.h"
 #include "gateway_client.h"
 #include "originator.h"
 #include "network-coding.h"
 #include "fragmentation.h"

 static void batadv_send_outstanding_bcast_packet(struct work_struct *work);

 /* send out an already prepared packet to the given address via the
  * specified batman interface
  */
 int batadv_send_skb_packet(struct sk_buff *skb,
 			   struct batadv_hard_iface *hard_iface,
 			   const uint8_t *dst_addr)
 {
 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 	struct ethhdr *ethhdr;

 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
 		goto send_skb_err;

 	if (unlikely(!hard_iface->net_dev))
 		goto send_skb_err;

 	if (!(hard_iface->net_dev->flags & IFF_UP)) {
 		pr_warn("Interface %s is not up - can't send packet via that interface!\n",
 			hard_iface->net_dev->name);
 		goto send_skb_err;
 	}

 	/* push to the ethernet header. */
 	if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
 		goto send_skb_err;

 	skb_reset_mac_header(skb);

 	ethhdr = eth_hdr(skb);
 	memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
 	memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
 	ethhdr->h_proto = htons(ETH_P_BATMAN);

 	skb_set_network_header(skb, ETH_HLEN);
 	skb->protocol = htons(ETH_P_BATMAN);

 	skb->dev = hard_iface->net_dev;

 	/* Save a clone of the skb to use when decoding coded packets */
 	batadv_nc_skb_store_for_decoding(bat_priv, skb);

 	/* dev_queue_xmit() returns a negative result on error.	 However on
 	 * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
 	 * (which is > 0). This will not be treated as an error.
 	 */
 	return dev_queue_xmit(skb);
 send_skb_err:
 	kfree_skb(skb);
 	return NET_XMIT_DROP;
 }

 /**
  * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
  * @skb: Packet to be transmitted.
  * @orig_node: Final destination of the packet.
  * @recv_if: Interface used when receiving the packet (can be NULL).
  *
  * Looks up the best next-hop towards the passed originator and passes the
  * skb on for preparation of MAC header. If the packet originated from this
  * host, NULL can be passed as recv_if and no interface alternating is
  * attempted.
  *
  * Returns NET_XMIT_SUCCESS on success, NET_XMIT_DROP on failure, or
  * NET_XMIT_POLICED if the skb is buffered for later transmit.
  */
 int batadv_send_skb_to_orig(struct sk_buff *skb,
 			    struct batadv_orig_node *orig_node,
 			    struct batadv_hard_iface *recv_if)
 {
 	struct batadv_priv *bat_priv = orig_node->bat_priv;
 	struct batadv_neigh_node *neigh_node;
 	int ret = NET_XMIT_DROP;

 	/* batadv_find_router() increases neigh_nodes refcount if found. */
 	neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 	if (!neigh_node)
 		goto out;

 	/* Check if the skb is too large to send in one piece and fragment
 	 * it if needed.
 	 */
 	if (atomic_read(&bat_priv->fragmentation) &&
 	    skb->len > neigh_node->if_incoming->net_dev->mtu) {
 		/* Fragment and send packet. */
 		if (batadv_frag_send_packet(skb, orig_node, neigh_node))
 			ret = NET_XMIT_SUCCESS;

 		goto out;
 	}

 	/* try to network code the packet, if it is received on an interface
 	 * (i.e. being forwarded). If the packet originates from this node or if
 	 * network coding fails, then send the packet as usual.
 	 */
 	if (recv_if && batadv_nc_skb_forward(skb, neigh_node)) {
 		ret = NET_XMIT_POLICED;
 	} else {
 		batadv_send_skb_packet(skb, neigh_node->if_incoming,
 				       neigh_node->addr);
 		ret = NET_XMIT_SUCCESS;
 	}

 out:
 	if (neigh_node)
 		batadv_neigh_node_free_ref(neigh_node);

 	return ret;
 }

 /**
  * batadv_send_skb_push_fill_unicast - extend the buffer and initialize the
  *  common fields for unicast packets
  * @skb: the skb carrying the unicast header to initialize
  * @hdr_size: amount of bytes to push at the beginning of the skb
  * @orig_node: the destination node
  *
  * Returns false if the buffer extension was not possible or true otherwise.
  */
 static bool
 batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
 				  struct batadv_orig_node *orig_node)
 {
 	struct batadv_unicast_packet *unicast_packet;
 	uint8_t ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);

 	if (batadv_skb_head_push(skb, hdr_size) < 0)
 		return false;

 	unicast_packet = (struct batadv_unicast_packet *)skb->data;
 	unicast_packet->version = BATADV_COMPAT_VERSION;
 	/* batman packet type: unicast */
 	unicast_packet->packet_type = BATADV_UNICAST;
 	/* set unicast ttl */
 	unicast_packet->ttl = BATADV_TTL;
 	/* copy the destination for faster routing */
 	memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN);
 	/* set the destination tt version number */
 	unicast_packet->ttvn = ttvn;

 	return true;
 }

 /**
  * batadv_send_skb_prepare_unicast - encapsulate an skb with a unicast header
  * @skb: the skb containing the payload to encapsulate
  * @orig_node: the destination node
  *
  * Returns false if the payload could not be encapsulated or true otherwise.
  */
 static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
 					    struct batadv_orig_node *orig_node)
 {
 	size_t uni_size = sizeof(struct batadv_unicast_packet);

 	return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
 }

 /**
  * batadv_send_skb_prepare_unicast_4addr - encapsulate an skb with a
  *  unicast 4addr header
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: the skb containing the payload to encapsulate
  * @orig_node: the destination node
  * @packet_subtype: the unicast 4addr packet subtype to use
  *
  * Returns false if the payload could not be encapsulated or true otherwise.
  */
 bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
 					   struct sk_buff *skb,
 					   struct batadv_orig_node *orig,
 					   int packet_subtype)
 {
 	struct batadv_hard_iface *primary_if;
 	struct batadv_unicast_4addr_packet *uc_4addr_packet;
 	bool ret = false;

 	primary_if = batadv_primary_if_get_selected(bat_priv);
 	if (!primary_if)
 		goto out;

 	/* Pull the header space and fill the unicast_packet substructure.
 	 * We can do that because the first member of the uc_4addr_packet
 	 * is of type struct unicast_packet
 	 */
 	if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
 					       orig))
 		goto out;

 	uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
 	uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
 	memcpy(uc_4addr_packet->src, primary_if->net_dev->dev_addr, ETH_ALEN);
 	uc_4addr_packet->subtype = packet_subtype;
 	uc_4addr_packet->reserved = 0;

 	ret = true;
 out:
 	if (primary_if)
 		batadv_hardif_free_ref(primary_if);
 	return ret;
 }

 /**
  * batadv_send_skb_unicast - encapsulate and send an skb via unicast
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: payload to send
  * @packet_type: the batman unicast packet type to use
  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
  *  4addr packets)
  * @orig_node: the originator to send the packet to
  * @vid: the vid to be used to search the translation table
  *
  * Wrap the given skb into a batman-adv unicast or unicast-4addr header
  * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
  * as packet_type. Then send this frame to the given orig_node and release a
  * reference to this orig_node.
  *
  * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
  */
 static int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
 				   struct sk_buff *skb, int packet_type,
 				   int packet_subtype,
 				   struct batadv_orig_node *orig_node,
 				   unsigned short vid)
 {
 	struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
 	struct batadv_unicast_packet *unicast_packet;
 	int ret = NET_XMIT_DROP;

 	if (!orig_node)
 		goto out;

 	switch (packet_type) {
 	case BATADV_UNICAST:
 		if (!batadv_send_skb_prepare_unicast(skb, orig_node))
 			goto out;
 		break;
 	case BATADV_UNICAST_4ADDR:
 		if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
 							   orig_node,
 							   packet_subtype))
 			goto out;
 		break;
 	default:
 		/* this function supports UNICAST and UNICAST_4ADDR only. It
 		 * should never be invoked with any other packet type
 		 */
 		goto out;
 	}

 	unicast_packet = (struct batadv_unicast_packet *)skb->data;

 	/* inform the destination node that we are still missing a correct route
 	 * for this client. The destination will receive this packet and will
 	 * try to reroute it because the ttvn contained in the header is less
 	 * than the current one
 	 */
 	if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
 		unicast_packet->ttvn = unicast_packet->ttvn - 1;

 	if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
 		ret = NET_XMIT_SUCCESS;

 out:
 	if (orig_node)
 		batadv_orig_node_free_ref(orig_node);
 	if (ret == NET_XMIT_DROP)
 		kfree_skb(skb);
 	return ret;
 }

 /**
  * batadv_send_skb_via_tt_generic - send an skb via TT lookup
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: payload to send
  * @packet_type: the batman unicast packet type to use
  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
  *  4addr packets)
  * @vid: the vid to be used to search the translation table
  *
  * Look up the recipient node for the destination address in the ethernet
  * header via the translation table. Wrap the given skb into a batman-adv
  * unicast or unicast-4addr header depending on whether BATADV_UNICAST or
  * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
  * to the according destination node.
  *
  * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
  */
 int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
 				   struct sk_buff *skb, int packet_type,
 				   int packet_subtype, uint8_t *dst_hint,
 				   unsigned short vid)
 {
 	struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
 	struct batadv_orig_node *orig_node;
 	uint8_t *src, *dst;

 	src = ethhdr->h_source;
 	dst = ethhdr->h_dest;

 	/* if we got an hint! let's send the packet to this client (if any) */
 	if (dst_hint) {
 		src = NULL;
 		dst = dst_hint;
 	}
 	orig_node = batadv_transtable_search(bat_priv, src, dst, vid);

 	return batadv_send_skb_unicast(bat_priv, skb, packet_type,
 				       packet_subtype, orig_node, vid);
 }

 /**
  * batadv_send_skb_via_gw - send an skb via gateway lookup
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: payload to send
  * @vid: the vid to be used to search the translation table
  *
  * Look up the currently selected gateway. Wrap the given skb into a batman-adv
  * unicast header and send this frame to this gateway node.
  *
  * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
  */
 int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
 			   unsigned short vid)
 {
 	struct batadv_orig_node *orig_node;

 	orig_node = batadv_gw_get_selected_orig(bat_priv);
 	return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
 				       orig_node, vid);
 }

 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
 {
 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);

 	if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
 	    (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
 		return;

 	/* the interface gets activated here to avoid race conditions between
 	 * the moment of activating the interface in
 	 * hardif_activate_interface() where the originator mac is set and
 	 * outdated packets (especially uninitialized mac addresses) in the
 	 * packet queue
 	 */
 	if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
 		hard_iface->if_status = BATADV_IF_ACTIVE;

 	bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
 }

 static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
 {
 	if (forw_packet->skb)
 		kfree_skb(forw_packet->skb);
 	if (forw_packet->if_incoming)
 		batadv_hardif_free_ref(forw_packet->if_incoming);
 	kfree(forw_packet);
 }

 static void
 _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 				 struct batadv_forw_packet *forw_packet,
 				 unsigned long send_time)
 {
 	/* add new packet to packet list */
 	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 	hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

 	/* start timer for this packet */
 	queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
 			   send_time);
 }

 /* add a broadcast packet to the queue and setup timers. broadcast packets
  * are sent multiple times to increase probability for being received.
  *
  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
  * errors.
  *
  * The skb is not consumed, so the caller should make sure that the
  * skb is freed.
  */
 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 				    const struct sk_buff *skb,
 				    unsigned long delay)
 {
 	struct batadv_hard_iface *primary_if = NULL;
 	struct batadv_forw_packet *forw_packet;
 	struct batadv_bcast_packet *bcast_packet;
 	struct sk_buff *newskb;

 	if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 			   "bcast packet queue full\n");
 		goto out;
 	}

 	primary_if = batadv_primary_if_get_selected(bat_priv);
 	if (!primary_if)
 		goto out_and_inc;

 	forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);

 	if (!forw_packet)
 		goto out_and_inc;

 	newskb = skb_copy(skb, GFP_ATOMIC);
 	if (!newskb)
 		goto packet_free;

 	/* as we have a copy now, it is safe to decrease the TTL */
 	bcast_packet = (struct batadv_bcast_packet *)newskb->data;
 	bcast_packet->ttl--;

 	skb_reset_mac_header(newskb);

 	forw_packet->skb = newskb;
 	forw_packet->if_incoming = primary_if;

 	/* how often did we send the bcast packet ? */
 	forw_packet->num_packets = 0;

 	INIT_DELAYED_WORK(&forw_packet->delayed_work,
 			  batadv_send_outstanding_bcast_packet);

 	_batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
 	return NETDEV_TX_OK;

 packet_free:
 	kfree(forw_packet);
 out_and_inc:
 	atomic_inc(&bat_priv->bcast_queue_left);
 out:
 	if (primary_if)
 		batadv_hardif_free_ref(primary_if);
 	return NETDEV_TX_BUSY;
 }

 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 {
 	struct batadv_hard_iface *hard_iface;
 	struct delayed_work *delayed_work;
 	struct batadv_forw_packet *forw_packet;
 	struct sk_buff *skb1;
 	struct net_device *soft_iface;
 	struct batadv_priv *bat_priv;

 	delayed_work = container_of(work, struct delayed_work, work);
 	forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 				   delayed_work);
 	soft_iface = forw_packet->if_incoming->soft_iface;
 	bat_priv = netdev_priv(soft_iface);

 	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 	hlist_del(&forw_packet->list);
 	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

 	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 		goto out;

 	if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet))
 		goto out;

 	/* rebroadcast packet */
 	rcu_read_lock();
 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 		if (hard_iface->soft_iface != soft_iface)
 			continue;

 		if (forw_packet->num_packets >= hard_iface->num_bcasts)
 			continue;

 		/* send a copy of the saved skb */
 		skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 		if (skb1)
 			batadv_send_skb_packet(skb1, hard_iface,
 					       batadv_broadcast_addr);
 	}
 	rcu_read_unlock();

 	forw_packet->num_packets++;

 	/* if we still have some more bcasts to send */
 	if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) {
 		_batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
 						 msecs_to_jiffies(5));
 		return;
 	}

 out:
 	batadv_forw_packet_free(forw_packet);
 	atomic_inc(&bat_priv->bcast_queue_left);
 }

 void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
 {
 	struct delayed_work *delayed_work;
 	struct batadv_forw_packet *forw_packet;
 	struct batadv_priv *bat_priv;

 	delayed_work = container_of(work, struct delayed_work, work);
 	forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 				   delayed_work);
 	bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 	spin_lock_bh(&bat_priv->forw_bat_list_lock);
 	hlist_del(&forw_packet->list);
 	spin_unlock_bh(&bat_priv->forw_bat_list_lock);

 	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 		goto out;

 	bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);

 	/* we have to have at least one packet in the queue
 	 * to determine the queues wake up time unless we are
 	 * shutting down
 	 */
 	if (forw_packet->own)
 		batadv_schedule_bat_ogm(forw_packet->if_incoming);

 out:
 	/* don't count own packet */
 	if (!forw_packet->own)
 		atomic_inc(&bat_priv->batman_queue_left);

 	batadv_forw_packet_free(forw_packet);
 }

 void
 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
 				 const struct batadv_hard_iface *hard_iface)
 {
 	struct batadv_forw_packet *forw_packet;
 	struct hlist_node *safe_tmp_node;
 	bool pending;

 	if (hard_iface)
 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 			   "purge_outstanding_packets(): %s\n",
 			   hard_iface->net_dev->name);
 	else
 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 			   "purge_outstanding_packets()\n");

 	/* free bcast list */
 	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 	hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 				  &bat_priv->forw_bcast_list, list) {
 		/* if purge_outstanding_packets() was called with an argument
 		 * we delete only packets belonging to the given interface
 		 */
 		if ((hard_iface) &&
 		    (forw_packet->if_incoming != hard_iface))
 			continue;

 		spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

 		/* batadv_send_outstanding_bcast_packet() will lock the list to
 		 * delete the item from the list
 		 */
 		pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 		spin_lock_bh(&bat_priv->forw_bcast_list_lock);

 		if (pending) {
 			hlist_del(&forw_packet->list);
 			batadv_forw_packet_free(forw_packet);
 		}
 	}
 	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

 	/* free batman packet list */
 	spin_lock_bh(&bat_priv->forw_bat_list_lock);
 	hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 				  &bat_priv->forw_bat_list, list) {
 		/* if purge_outstanding_packets() was called with an argument
 		 * we delete only packets belonging to the given interface
 		 */
 		if ((hard_iface) &&
 		    (forw_packet->if_incoming != hard_iface))
 			continue;

 		spin_unlock_bh(&bat_priv->forw_bat_list_lock);

 		/* send_outstanding_bat_packet() will lock the list to
 		 * delete the item from the list
 		 */
 		pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 		spin_lock_bh(&bat_priv->forw_bat_list_lock);

 		if (pending) {
 			hlist_del(&forw_packet->list);
 			batadv_forw_packet_free(forw_packet);
 		}
 	}
 	spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 }
	/* Copyright (C) 2007-2013 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 "main.h"
	#include "distributed-arp-table.h"
	#include "send.h"
	#include "routing.h"
	#include "translation-table.h"
	#include "soft-interface.h"
	#include "hard-interface.h"
	#include "gateway_common.h"
	#include "gateway_client.h"
	#include "originator.h"
	#include "network-coding.h"
	#include "fragmentation.h"

	static void batadv_send_outstanding_bcast_packet(struct work_struct *work);

	/* send out an already prepared packet to the given address via the
	* specified batman interface
	*/
	int batadv_send_skb_packet(struct sk_buff *skb,
	struct batadv_hard_iface *hard_iface,
	const uint8_t *dst_addr)
	{
	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
	struct ethhdr *ethhdr;

	if (hard_iface->if_status != BATADV_IF_ACTIVE)
	goto send_skb_err;

	if (unlikely(!hard_iface->net_dev))
	goto send_skb_err;

	if (!(hard_iface->net_dev->flags & IFF_UP)) {
	pr_warn("Interface %s is not up - can't send packet via that interface!\n",
	hard_iface->net_dev->name);
	goto send_skb_err;
	}

	/* push to the ethernet header. */
	if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
	goto send_skb_err;

	skb_reset_mac_header(skb);

	ethhdr = eth_hdr(skb);
	memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
	memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
	ethhdr->h_proto = htons(ETH_P_BATMAN);

	skb_set_network_header(skb, ETH_HLEN);
	skb->protocol = htons(ETH_P_BATMAN);

	skb->dev = hard_iface->net_dev;

	/* Save a clone of the skb to use when decoding coded packets */
	batadv_nc_skb_store_for_decoding(bat_priv, skb);

	/* dev_queue_xmit() returns a negative result on error. However on
	* congestion and traffic shaping, it drops and returns NET_XMIT_DROP
	* (which is > 0). This will not be treated as an error.
	*/
	return dev_queue_xmit(skb);
	send_skb_err:
	kfree_skb(skb);
	return NET_XMIT_DROP;
	}

	/**
	* batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
	* @skb: Packet to be transmitted.
	* @orig_node: Final destination of the packet.
	* @recv_if: Interface used when receiving the packet (can be NULL).
	*
	* Looks up the best next-hop towards the passed originator and passes the
	* skb on for preparation of MAC header. If the packet originated from this
	* host, NULL can be passed as recv_if and no interface alternating is
	* attempted.
	*
	* Returns NET_XMIT_SUCCESS on success, NET_XMIT_DROP on failure, or
	* NET_XMIT_POLICED if the skb is buffered for later transmit.
	*/
	int batadv_send_skb_to_orig(struct sk_buff *skb,
	struct batadv_orig_node *orig_node,
	struct batadv_hard_iface *recv_if)
	{
	struct batadv_priv *bat_priv = orig_node->bat_priv;
	struct batadv_neigh_node *neigh_node;
	int ret = NET_XMIT_DROP;

	/* batadv_find_router() increases neigh_nodes refcount if found. */
	neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
	if (!neigh_node)
	goto out;

	/* Check if the skb is too large to send in one piece and fragment
	* it if needed.
	*/
	if (atomic_read(&bat_priv->fragmentation) &&
	skb->len > neigh_node->if_incoming->net_dev->mtu) {
	/* Fragment and send packet. */
	if (batadv_frag_send_packet(skb, orig_node, neigh_node))
	ret = NET_XMIT_SUCCESS;

	goto out;
	}

	/* try to network code the packet, if it is received on an interface
	* (i.e. being forwarded). If the packet originates from this node or if
	* network coding fails, then send the packet as usual.
	*/
	if (recv_if && batadv_nc_skb_forward(skb, neigh_node)) {
	ret = NET_XMIT_POLICED;
	} else {
	batadv_send_skb_packet(skb, neigh_node->if_incoming,
	neigh_node->addr);
	ret = NET_XMIT_SUCCESS;
	}

	out:
	if (neigh_node)
	batadv_neigh_node_free_ref(neigh_node);

	return ret;
	}

	/**
	* batadv_send_skb_push_fill_unicast - extend the buffer and initialize the
	* common fields for unicast packets
	* @skb: the skb carrying the unicast header to initialize
	* @hdr_size: amount of bytes to push at the beginning of the skb
	* @orig_node: the destination node
	*
	* Returns false if the buffer extension was not possible or true otherwise.
	*/
	static bool
	batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
	struct batadv_orig_node *orig_node)
	{
	struct batadv_unicast_packet *unicast_packet;
	uint8_t ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);

	if (batadv_skb_head_push(skb, hdr_size) < 0)
	return false;

	unicast_packet = (struct batadv_unicast_packet *)skb->data;
	unicast_packet->version = BATADV_COMPAT_VERSION;
	/* batman packet type: unicast */
	unicast_packet->packet_type = BATADV_UNICAST;
	/* set unicast ttl */
	unicast_packet->ttl = BATADV_TTL;
	/* copy the destination for faster routing */
	memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN);
	/* set the destination tt version number */
	unicast_packet->ttvn = ttvn;

	return true;
	}

	/**
	* batadv_send_skb_prepare_unicast - encapsulate an skb with a unicast header
	* @skb: the skb containing the payload to encapsulate
	* @orig_node: the destination node
	*
	* Returns false if the payload could not be encapsulated or true otherwise.
	*/
	static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
	struct batadv_orig_node *orig_node)
	{
	size_t uni_size = sizeof(struct batadv_unicast_packet);

	return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
	}

	/**
	* batadv_send_skb_prepare_unicast_4addr - encapsulate an skb with a
	* unicast 4addr header
	* @bat_priv: the bat priv with all the soft interface information
	* @skb: the skb containing the payload to encapsulate
	* @orig_node: the destination node
	* @packet_subtype: the unicast 4addr packet subtype to use
	*
	* Returns false if the payload could not be encapsulated or true otherwise.
	*/
	bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
	struct sk_buff *skb,
	struct batadv_orig_node *orig,
	int packet_subtype)
	{
	struct batadv_hard_iface *primary_if;
	struct batadv_unicast_4addr_packet *uc_4addr_packet;
	bool ret = false;

	primary_if = batadv_primary_if_get_selected(bat_priv);
	if (!primary_if)
	goto out;

	/* Pull the header space and fill the unicast_packet substructure.
	* We can do that because the first member of the uc_4addr_packet
	* is of type struct unicast_packet
	*/
	if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
	orig))
	goto out;

	uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
	uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
	memcpy(uc_4addr_packet->src, primary_if->net_dev->dev_addr, ETH_ALEN);
	uc_4addr_packet->subtype = packet_subtype;
	uc_4addr_packet->reserved = 0;

	ret = true;
	out:
	if (primary_if)
	batadv_hardif_free_ref(primary_if);
	return ret;
	}

	/**
	* batadv_send_skb_unicast - encapsulate and send an skb via unicast
	* @bat_priv: the bat priv with all the soft interface information
	* @skb: payload to send
	* @packet_type: the batman unicast packet type to use
	* @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
	* 4addr packets)
	* @orig_node: the originator to send the packet to
	* @vid: the vid to be used to search the translation table
	*
	* Wrap the given skb into a batman-adv unicast or unicast-4addr header
	* depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
	* as packet_type. Then send this frame to the given orig_node and release a
	* reference to this orig_node.
	*
	* Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
	*/
	static int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
	struct sk_buff *skb, int packet_type,
	int packet_subtype,
	struct batadv_orig_node *orig_node,
	unsigned short vid)
	{
	struct ethhdr ethhdr = (struct ethhdr )skb->data;
	struct batadv_unicast_packet *unicast_packet;
	int ret = NET_XMIT_DROP;

	if (!orig_node)
	goto out;

	switch (packet_type) {
	case BATADV_UNICAST:
	if (!batadv_send_skb_prepare_unicast(skb, orig_node))
	goto out;
	break;
	case BATADV_UNICAST_4ADDR:
	if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
	orig_node,
	packet_subtype))
	goto out;
	break;
	default:
	/* this function supports UNICAST and UNICAST_4ADDR only. It
	* should never be invoked with any other packet type
	*/
	goto out;
	}

	unicast_packet = (struct batadv_unicast_packet *)skb->data;

	/* inform the destination node that we are still missing a correct route
	* for this client. The destination will receive this packet and will
	* try to reroute it because the ttvn contained in the header is less
	* than the current one
	*/
	if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
	unicast_packet->ttvn = unicast_packet->ttvn - 1;

	if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
	ret = NET_XMIT_SUCCESS;

	out:
	if (orig_node)
	batadv_orig_node_free_ref(orig_node);
	if (ret == NET_XMIT_DROP)
	kfree_skb(skb);
	return ret;
	}

	/**
	* batadv_send_skb_via_tt_generic - send an skb via TT lookup
	* @bat_priv: the bat priv with all the soft interface information
	* @skb: payload to send
	* @packet_type: the batman unicast packet type to use
	* @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
	* 4addr packets)
	* @vid: the vid to be used to search the translation table
	*
	* Look up the recipient node for the destination address in the ethernet
	* header via the translation table. Wrap the given skb into a batman-adv
	* unicast or unicast-4addr header depending on whether BATADV_UNICAST or
	* BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
	* to the according destination node.
	*
	* Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
	*/
	int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
	struct sk_buff *skb, int packet_type,
	int packet_subtype, uint8_t *dst_hint,
	unsigned short vid)
	{
	struct ethhdr ethhdr = (struct ethhdr )skb->data;
	struct batadv_orig_node *orig_node;
	uint8_t src, dst;

	src = ethhdr->h_source;
	dst = ethhdr->h_dest;

	/* if we got an hint! let's send the packet to this client (if any) */
	if (dst_hint) {
	src = NULL;
	dst = dst_hint;
	}
	orig_node = batadv_transtable_search(bat_priv, src, dst, vid);

	return batadv_send_skb_unicast(bat_priv, skb, packet_type,
	packet_subtype, orig_node, vid);
	}

	/**
	* batadv_send_skb_via_gw - send an skb via gateway lookup
	* @bat_priv: the bat priv with all the soft interface information
	* @skb: payload to send
	* @vid: the vid to be used to search the translation table
	*
	* Look up the currently selected gateway. Wrap the given skb into a batman-adv
	* unicast header and send this frame to this gateway node.
	*
	* Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
	*/
	int batadv_send_skb_via_gw(struct batadv_priv bat_priv, struct sk_buff skb,
	unsigned short vid)
	{
	struct batadv_orig_node *orig_node;

	orig_node = batadv_gw_get_selected_orig(bat_priv);
	return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
	orig_node, vid);
	}

	void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
	{
	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);

	if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) \|\|
	(hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
	return;

	/* the interface gets activated here to avoid race conditions between
	* the moment of activating the interface in
	* hardif_activate_interface() where the originator mac is set and
	* outdated packets (especially uninitialized mac addresses) in the
	* packet queue
	*/
	if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
	hard_iface->if_status = BATADV_IF_ACTIVE;

	bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
	}

	static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
	{
	if (forw_packet->skb)
	kfree_skb(forw_packet->skb);
	if (forw_packet->if_incoming)
	batadv_hardif_free_ref(forw_packet->if_incoming);
	kfree(forw_packet);
	}

	static void
	_batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
	struct batadv_forw_packet *forw_packet,
	unsigned long send_time)
	{
	/* add new packet to packet list */
	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
	hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

	/* start timer for this packet */
	queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
	send_time);
	}

	/* add a broadcast packet to the queue and setup timers. broadcast packets
	* are sent multiple times to increase probability for being received.
	*
	* This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
	* errors.
	*
	* The skb is not consumed, so the caller should make sure that the
	* skb is freed.
	*/
	int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
	const struct sk_buff *skb,
	unsigned long delay)
	{
	struct batadv_hard_iface *primary_if = NULL;
	struct batadv_forw_packet *forw_packet;
	struct batadv_bcast_packet *bcast_packet;
	struct sk_buff *newskb;

	if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	"bcast packet queue full\n");
	goto out;
	}

	primary_if = batadv_primary_if_get_selected(bat_priv);
	if (!primary_if)
	goto out_and_inc;

	forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);

	if (!forw_packet)
	goto out_and_inc;

	newskb = skb_copy(skb, GFP_ATOMIC);
	if (!newskb)
	goto packet_free;

	/* as we have a copy now, it is safe to decrease the TTL */
	bcast_packet = (struct batadv_bcast_packet *)newskb->data;
	bcast_packet->ttl--;

	skb_reset_mac_header(newskb);

	forw_packet->skb = newskb;
	forw_packet->if_incoming = primary_if;

	/* how often did we send the bcast packet ? */
	forw_packet->num_packets = 0;

	INIT_DELAYED_WORK(&forw_packet->delayed_work,
	batadv_send_outstanding_bcast_packet);

	_batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
	return NETDEV_TX_OK;

	packet_free:
	kfree(forw_packet);
	out_and_inc:
	atomic_inc(&bat_priv->bcast_queue_left);
	out:
	if (primary_if)
	batadv_hardif_free_ref(primary_if);
	return NETDEV_TX_BUSY;
	}

	static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
	{
	struct batadv_hard_iface *hard_iface;
	struct delayed_work *delayed_work;
	struct batadv_forw_packet *forw_packet;
	struct sk_buff *skb1;
	struct net_device *soft_iface;
	struct batadv_priv *bat_priv;

	delayed_work = container_of(work, struct delayed_work, work);
	forw_packet = container_of(delayed_work, struct batadv_forw_packet,
	delayed_work);
	soft_iface = forw_packet->if_incoming->soft_iface;
	bat_priv = netdev_priv(soft_iface);

	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
	hlist_del(&forw_packet->list);
	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
	goto out;

	if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet))
	goto out;

	/* rebroadcast packet */
	rcu_read_lock();
	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
	if (hard_iface->soft_iface != soft_iface)
	continue;

	if (forw_packet->num_packets >= hard_iface->num_bcasts)
	continue;

	/* send a copy of the saved skb */
	skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
	if (skb1)
	batadv_send_skb_packet(skb1, hard_iface,
	batadv_broadcast_addr);
	}
	rcu_read_unlock();

	forw_packet->num_packets++;

	/* if we still have some more bcasts to send */
	if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) {
	_batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
	msecs_to_jiffies(5));
	return;
	}

	out:
	batadv_forw_packet_free(forw_packet);
	atomic_inc(&bat_priv->bcast_queue_left);
	}

	void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
	{
	struct delayed_work *delayed_work;
	struct batadv_forw_packet *forw_packet;
	struct batadv_priv *bat_priv;

	delayed_work = container_of(work, struct delayed_work, work);
	forw_packet = container_of(delayed_work, struct batadv_forw_packet,
	delayed_work);
	bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
	spin_lock_bh(&bat_priv->forw_bat_list_lock);
	hlist_del(&forw_packet->list);
	spin_unlock_bh(&bat_priv->forw_bat_list_lock);

	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
	goto out;

	bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);

	/* we have to have at least one packet in the queue
	* to determine the queues wake up time unless we are
	* shutting down
	*/
	if (forw_packet->own)
	batadv_schedule_bat_ogm(forw_packet->if_incoming);

	out:
	/* don't count own packet */
	if (!forw_packet->own)
	atomic_inc(&bat_priv->batman_queue_left);

	batadv_forw_packet_free(forw_packet);
	}

	void
	batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
	const struct batadv_hard_iface *hard_iface)
	{
	struct batadv_forw_packet *forw_packet;
	struct hlist_node *safe_tmp_node;
	bool pending;

	if (hard_iface)
	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	"purge_outstanding_packets(): %s\n",
	hard_iface->net_dev->name);
	else
	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	"purge_outstanding_packets()\n");

	/* free bcast list */
	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
	hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
	&bat_priv->forw_bcast_list, list) {
	/* if purge_outstanding_packets() was called with an argument
	* we delete only packets belonging to the given interface
	*/
	if ((hard_iface) &&
	(forw_packet->if_incoming != hard_iface))
	continue;

	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

	/* batadv_send_outstanding_bcast_packet() will lock the list to
	* delete the item from the list
	*/
	pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
	spin_lock_bh(&bat_priv->forw_bcast_list_lock);

	if (pending) {
	hlist_del(&forw_packet->list);
	batadv_forw_packet_free(forw_packet);
	}
	}
	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

	/* free batman packet list */
	spin_lock_bh(&bat_priv->forw_bat_list_lock);
	hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
	&bat_priv->forw_bat_list, list) {
	/* if purge_outstanding_packets() was called with an argument
	* we delete only packets belonging to the given interface
	*/
	if ((hard_iface) &&
	(forw_packet->if_incoming != hard_iface))
	continue;

	spin_unlock_bh(&bat_priv->forw_bat_list_lock);

	/* send_outstanding_bat_packet() will lock the list to
	* delete the item from the list
	*/
	pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
	spin_lock_bh(&bat_priv->forw_bat_list_lock);

	if (pending) {
	hlist_del(&forw_packet->list);
	batadv_forw_packet_free(forw_packet);
	}
	}
	spin_unlock_bh(&bat_priv->forw_bat_list_lock);
	}