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: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

1 files changed, 9 insertions, 29 deletions

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 57e0af9b39e4..a40cdf273625 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -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);
 }