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Commit 55158629 authored by Linus Lüssing's avatar Linus Lüssing Committed by Sven Eckelmann
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batman-adv: Move bonding / iface alternating router search to own functions 



This decreases the size of find_router() by outsourcing the router
search for the bonding and interface alternating modes to their own sub
functions. This shall make it easier to keep track of the correct
refcounting later.

Signed-off-by: default avatarLinus Lüssing <linus.luessing@web.de>
Signed-off-by: default avatarMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
parent 0ce790e7

net/batman-adv/routing.c

+105 −75
Original line number Diff line number Diff line
@@ -1092,6 +1092,106 @@ int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if) 
	return ret;

}



/* In the bonding case, send the packets in a round

 * robin fashion over the remaining interfaces.

 *

 * This method rotates the bonding list and increases the

 * returned router's refcount. */

static struct neigh_node *find_bond_router(struct orig_node *primary_orig,

					   struct hard_iface *recv_if)

{

	struct neigh_node *tmp_neigh_node;

	struct neigh_node *router = NULL, *first_candidate = NULL;



	rcu_read_lock();

	list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,

				bonding_list) {

		if (!first_candidate)

			first_candidate = tmp_neigh_node;



		/* recv_if == NULL on the first node. */

		if (tmp_neigh_node->if_incoming == recv_if)

			continue;



		if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))

			continue;



		router = tmp_neigh_node;

		break;

	}



	/* use the first candidate if nothing was found. */

	if (!router && first_candidate &&

	    atomic_inc_not_zero(&first_candidate->refcount))

		router = first_candidate;



	if (!router)

		goto out;



	/* selected should point to the next element

	 * after the current router */

	spin_lock_bh(&primary_orig->neigh_list_lock);

	/* this is a list_move(), which unfortunately

	 * does not exist as rcu version */

	list_del_rcu(&primary_orig->bond_list);

	list_add_rcu(&primary_orig->bond_list,

		     &router->bonding_list);

	spin_unlock_bh(&primary_orig->neigh_list_lock);



out:

	rcu_read_unlock();

	return router;

}



/* Interface Alternating: Use the best of the

 * remaining candidates which are not using

 * this interface.

 *

 * Increases the returned router's refcount */

static struct neigh_node *find_ifalter_router(struct orig_node *primary_orig,

					      struct hard_iface *recv_if)

{

	struct neigh_node *tmp_neigh_node;

	struct neigh_node *router = NULL, *first_candidate = NULL;



	rcu_read_lock();

	list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,

				bonding_list) {

		if (!first_candidate)

			first_candidate = tmp_neigh_node;



		/* recv_if == NULL on the first node. */

		if (tmp_neigh_node->if_incoming == recv_if)

			continue;



		if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))

			continue;



		/* if we don't have a router yet

		 * or this one is better, choose it. */

		if ((!router) ||

		    (tmp_neigh_node->tq_avg > router->tq_avg)) {

			/* decrement refcount of

			 * previously selected router */

			if (router)

				neigh_node_free_ref(router);



			router = tmp_neigh_node;

			atomic_inc_not_zero(&router->refcount);

		}



		neigh_node_free_ref(tmp_neigh_node);

	}



	/* use the first candidate if nothing was found. */

	if (!router && first_candidate &&

	    atomic_inc_not_zero(&first_candidate->refcount))

		router = first_candidate;



	rcu_read_unlock();

	return router;

}



/* find a suitable router for this originator, and use

 * bonding if possible. increases the found neighbors

 * refcount.*/
@@ -1101,7 +1201,7 @@ struct neigh_node *find_router(struct bat_priv *bat_priv, 
{

	struct orig_node *primary_orig_node;

	struct orig_node *router_orig;

	struct neigh_node *router, *first_candidate, *tmp_neigh_node;

	struct neigh_node *router;

	static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};

	int bonding_enabled;
@@ -1157,82 +1257,12 @@ struct neigh_node *find_router(struct bat_priv *bat_priv, 
	 * in. */



	neigh_node_free_ref(router);

	first_candidate = NULL;

	router = NULL;



	if (bonding_enabled) {

		/* in the bonding case, send the packets in a round

		 * robin fashion over the remaining interfaces. */



		list_for_each_entry_rcu(tmp_neigh_node,

				&primary_orig_node->bond_list, bonding_list) {

			if (!first_candidate)

				first_candidate = tmp_neigh_node;

			/* recv_if == NULL on the first node. */

			if (tmp_neigh_node->if_incoming != recv_if &&

			    atomic_inc_not_zero(&tmp_neigh_node->refcount)) {

				router = tmp_neigh_node;

				break;

			}

		}



		/* use the first candidate if nothing was found. */

		if (!router && first_candidate &&

		    atomic_inc_not_zero(&first_candidate->refcount))

			router = first_candidate;



		if (!router) {

			rcu_read_unlock();

			return NULL;

		}



		/* selected should point to the next element

		 * after the current router */

		spin_lock_bh(&primary_orig_node->neigh_list_lock);

		/* this is a list_move(), which unfortunately

		 * does not exist as rcu version */

		list_del_rcu(&primary_orig_node->bond_list);

		list_add_rcu(&primary_orig_node->bond_list,

				&router->bonding_list);

		spin_unlock_bh(&primary_orig_node->neigh_list_lock);



	} else {

		/* if bonding is disabled, use the best of the

		 * remaining candidates which are not using

		 * this interface. */

		list_for_each_entry_rcu(tmp_neigh_node,

			&primary_orig_node->bond_list, bonding_list) {

			if (!first_candidate)

				first_candidate = tmp_neigh_node;



			/* recv_if == NULL on the first node. */

			if (tmp_neigh_node->if_incoming == recv_if)

				continue;



			if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))

				continue;



			/* if we don't have a router yet

			 * or this one is better, choose it. */

			if ((!router) ||

			    (tmp_neigh_node->tq_avg > router->tq_avg)) {

				/* decrement refcount of

				 * previously selected router */

				if (router)

					neigh_node_free_ref(router);



				router = tmp_neigh_node;

				atomic_inc_not_zero(&router->refcount);

			}



			neigh_node_free_ref(tmp_neigh_node);

		}

	if (bonding_enabled)

		router = find_bond_router(primary_orig_node, recv_if);

	else

		router = find_ifalter_router(primary_orig_node, recv_if);



		/* use the first candidate if nothing was found. */

		if (!router && first_candidate &&

		    atomic_inc_not_zero(&first_candidate->refcount))

			router = first_candidate;

	}

return_router:

	rcu_read_unlock();

	return router;