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batman-adv: Introduce forward packet creation helper

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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>
This commit is contained in:
Linus Lüssing
2016-06-20 21:39:54 +02:00
committed by Simon Wunderlich
parent 4fd261bf58
commit a65e548131
4 changed files with 98 additions and 59 deletions
Download Patch File Download Diff File Expand all files Collapse all files

111
net/batman-adv/send.c
View File

@ -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);
}
}