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Commit a65e5481 authored by Linus Lüssing's avatar Linus Lüssing Committed by Simon Wunderlich
Browse files

batman-adv: Introduce forward packet creation helper 



This patch abstracts the forward packet creation into the new function
batadv_forw_packet_alloc().

The queue counting and interface reference counters are now handled
internally within batadv_forw_packet_alloc() and its
batadv_forw_packet_free() counterpart. This should reduce the risk of
having reference/queue counting bugs again and should increase
code readibility.

Signed-off-by: default avatarLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: default avatarMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
parent 4fd261bf

net/batman-adv/bat_iv_ogm.c

+9 −29
Original line number Diff line number Diff line
@@ -675,19 +675,12 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, 
	struct batadv_forw_packet *forw_packet_aggr;

	unsigned char *skb_buff;

	unsigned int skb_size;

	atomic_t *queue_left = own_packet ? NULL : &bat_priv->batman_queue_left;



	/* own packet should always be scheduled */

	if (!own_packet) {

		if (!batadv_atomic_dec_not_zero(&bat_priv->batman_queue_left)) {

			batadv_dbg(BATADV_DBG_BATMAN, bat_priv,

				   "batman packet queue full\n");

			return;

		}

	}



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

	forw_packet_aggr = batadv_forw_packet_alloc(if_incoming, if_outgoing,

						    queue_left, bat_priv);

	if (!forw_packet_aggr)

		goto out_nomem;

		return;



	if (atomic_read(&bat_priv->aggregated_ogms) &&

	    packet_len < BATADV_MAX_AGGREGATION_BYTES)
@@ -698,8 +691,11 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, 
	skb_size += ETH_HLEN;



	forw_packet_aggr->skb = netdev_alloc_skb_ip_align(NULL, skb_size);

	if (!forw_packet_aggr->skb)

		goto out_free_forw_packet;

	if (!forw_packet_aggr->skb) {

		batadv_forw_packet_free(forw_packet_aggr);

		return;

	}



	forw_packet_aggr->skb->priority = TC_PRIO_CONTROL;

	skb_reserve(forw_packet_aggr->skb, ETH_HLEN);
@@ -707,12 +703,7 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, 
	forw_packet_aggr->packet_len = packet_len;

	memcpy(skb_buff, packet_buff, packet_len);



	kref_get(&if_incoming->refcount);

	kref_get(&if_outgoing->refcount);

	forw_packet_aggr->own = own_packet;

	forw_packet_aggr->if_incoming = if_incoming;

	forw_packet_aggr->if_outgoing = if_outgoing;

	forw_packet_aggr->num_packets = 0;

	forw_packet_aggr->direct_link_flags = BATADV_NO_FLAGS;

	forw_packet_aggr->send_time = send_time;
@@ -731,13 +722,6 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, 
	queue_delayed_work(batadv_event_workqueue,

			   &forw_packet_aggr->delayed_work,

			   send_time - jiffies);



	return;

out_free_forw_packet:

	kfree(forw_packet_aggr);

out_nomem:

	if (!own_packet)

		atomic_inc(&bat_priv->batman_queue_left);

}



/* aggregate a new packet into the existing ogm packet */
@@ -1820,10 +1804,6 @@ static void batadv_iv_send_outstanding_bat_ogm_packet(struct work_struct *work) 
		batadv_iv_ogm_schedule(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);

}

net/batman-adv/send.c

+81 −30
Original line number Diff line number Diff line
@@ -439,6 +439,13 @@ int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb, 
				       BATADV_P_DATA, orig_node, vid);

}



/**

 * batadv_forw_packet_free - free a forwarding packet

 * @forw_packet: The packet to free

 *

 * This frees a forwarding packet and releases any resources it might

 * have claimed.

 */

void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)

{

	kfree_skb(forw_packet->skb);
@@ -446,9 +453,73 @@ void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet) 
		batadv_hardif_put(forw_packet->if_incoming);

	if (forw_packet->if_outgoing)

		batadv_hardif_put(forw_packet->if_outgoing);

	if (forw_packet->queue_left)

		atomic_inc(forw_packet->queue_left);

	kfree(forw_packet);

}



/**

 * batadv_forw_packet_alloc - allocate a forwarding packet

 * @if_incoming: The (optional) if_incoming to be grabbed

 * @if_outgoing: The (optional) if_outgoing to be grabbed

 * @queue_left: The (optional) queue counter to decrease

 * @bat_priv: The bat_priv for the mesh of this forw_packet

 *

 * Allocates a forwarding packet and tries to get a reference to the

 * (optional) if_incoming, if_outgoing and queue_left. If queue_left

 * is NULL then bat_priv is optional, too.

 *

 * Return: An allocated forwarding packet on success, NULL otherwise.

 */

struct batadv_forw_packet *

batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming,

			 struct batadv_hard_iface *if_outgoing,

			 atomic_t *queue_left,

			 struct batadv_priv *bat_priv)

{

	struct batadv_forw_packet *forw_packet;

	const char *qname;



	if (queue_left && !batadv_atomic_dec_not_zero(queue_left)) {

		qname = "unknown";



		if (queue_left == &bat_priv->bcast_queue_left)

			qname = "bcast";



		if (queue_left == &bat_priv->batman_queue_left)

			qname = "batman";



		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,

			   "%s queue is full\n", qname);



		return NULL;

	}



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

	if (!forw_packet)

		goto err;



	if (if_incoming)

		kref_get(&if_incoming->refcount);



	if (if_outgoing)

		kref_get(&if_outgoing->refcount);



	forw_packet->skb = NULL;

	forw_packet->queue_left = queue_left;

	forw_packet->if_incoming = if_incoming;

	forw_packet->if_outgoing = if_outgoing;

	forw_packet->num_packets = 0;



	return forw_packet;



err:

	if (queue_left)

		atomic_inc(queue_left);



	return NULL;

}



static void

_batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,

				 struct batadv_forw_packet *forw_packet,
@@ -487,24 +558,20 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, 
	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);

		goto err;



	forw_packet = batadv_forw_packet_alloc(primary_if, NULL,

					       &bat_priv->bcast_queue_left,

					       bat_priv);

	batadv_hardif_put(primary_if);

	if (!forw_packet)

		goto out_and_inc;

		goto err;



	newskb = skb_copy(skb, GFP_ATOMIC);

	if (!newskb)

		goto packet_free;

		goto err_packet_free;



	/* as we have a copy now, it is safe to decrease the TTL */

	bcast_packet = (struct batadv_bcast_packet *)newskb->data;
@@ -513,11 +580,6 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, 
	skb_reset_mac_header(newskb);



	forw_packet->skb = newskb;

	forw_packet->if_incoming = primary_if;

	forw_packet->if_outgoing = NULL;



	/* 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);
@@ -525,13 +587,9 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, 
	_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_put(primary_if);

err_packet_free:

	batadv_forw_packet_free(forw_packet);

err:

	return NETDEV_TX_BUSY;

}
@@ -592,7 +650,6 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work) 


out:

	batadv_forw_packet_free(forw_packet);

	atomic_inc(&bat_priv->bcast_queue_left);

}



void
@@ -633,9 +690,6 @@ batadv_purge_outstanding_packets(struct batadv_priv *bat_priv, 


		if (pending) {

			hlist_del(&forw_packet->list);

			if (!forw_packet->own)

				atomic_inc(&bat_priv->bcast_queue_left);



			batadv_forw_packet_free(forw_packet);

		}

	}
@@ -663,9 +717,6 @@ batadv_purge_outstanding_packets(struct batadv_priv *bat_priv, 


		if (pending) {

			hlist_del(&forw_packet->list);

			if (!forw_packet->own)

				atomic_inc(&bat_priv->batman_queue_left);



			batadv_forw_packet_free(forw_packet);

		}

	}

net/batman-adv/send.h

+6 −0
Original line number Diff line number Diff line
@@ -28,6 +28,12 @@ 
struct sk_buff;



void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet);

struct batadv_forw_packet *

batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming,

			 struct batadv_hard_iface *if_outgoing,

			 atomic_t *queue_left,

			 struct batadv_priv *bat_priv);



int batadv_send_skb_to_orig(struct sk_buff *skb,

			    struct batadv_orig_node *orig_node,

			    struct batadv_hard_iface *recv_if);

net/batman-adv/types.h

+2 −0
Original line number Diff line number Diff line
@@ -1375,6 +1375,7 @@ struct batadv_skb_cb { 
 *  locally generated packet

 * @if_outgoing: packet where the packet should be sent to, or NULL if

 *  unspecified

 * @queue_left: The queue (counter) this packet was applied to

 */

struct batadv_forw_packet {

	struct hlist_node list;
@@ -1387,6 +1388,7 @@ struct batadv_forw_packet { 
	struct delayed_work delayed_work;

	struct batadv_hard_iface *if_incoming;

	struct batadv_hard_iface *if_outgoing;

	atomic_t *queue_left;

};



/**