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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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
net/batman-adv/bat_iv_ogm.c
View File

@ -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);
}

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);
}
}

6
net/batman-adv/send.h
View File

@ -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);

2
net/batman-adv/types.h
View File

@ -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;
};
/**