diff options
author | Linus Lüssing <linus.luessing@c0d3.blue> | 2016-06-20 21:39:54 +0200 |
---|---|---|
committer | Simon Wunderlich <sw@simonwunderlich.de> | 2016-08-09 07:54:32 +0200 |
commit | a65e5481315e0754a20f58aa374423610a311f33 (patch) | |
tree | 32a59a2b19862ac384c81babaf03f3b18a7bcf47 /net/batman-adv/send.c | |
parent | 4fd261bf586b0fc932d5fd20d9b1648547b16eca (diff) | |
download | linux-a65e5481315e0754a20f58aa374423610a311f33.tar.bz2 |
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>
Diffstat (limited to 'net/batman-adv/send.c')
-rw-r--r-- | net/batman-adv/send.c | 111 |
1 files changed, 81 insertions, 30 deletions
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index 6191159484df..33d8bd14140c 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -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); } } |