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 --- Changelog v4: * Removed goto in batadv_iv_ogm_aggregate_new() * Removed two goto's in batadv_forw_packet_alloc() * Easier to read debug output code in batadv_forw_packet_alloc() * Renamed "out" and "packet_free" jump labels in batadv_add_bcast_packet_to_list() to "err" and "err_packet_free"
Changelog v3: * Fixed kernel doc for batadv_forw_packet_alloc() * New title / some more adjustments to commit message
Changelog v2: * Rebase to current master * Fixed typo: "ressources" vs. "resources" * Moved forw_packet->num_packets initialization into forw_packet_alloc(), too * Adjusted commit message
net/batman-adv/bat_iv_ogm.c | 38 ++++----------- net/batman-adv/send.c | 111 ++++++++++++++++++++++++++++++++------------ net/batman-adv/send.h | 6 +++ net/batman-adv/types.h | 2 + 4 files changed, 98 insertions(+), 59 deletions(-)
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 6af4462..d3c8c57 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -674,19 +674,12 @@ 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) @@ -697,8 +690,11 @@ 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);
@@ -706,12 +702,7 @@ 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;
@@ -730,13 +721,6 @@ 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 */ @@ -1819,10 +1803,6 @@ 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); }
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index 49836da..89c0ce3 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -430,6 +430,13 @@ int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb, 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); @@ -437,9 +444,73 @@ 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, @@ -478,24 +549,20 @@ 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; @@ -504,11 +571,6 @@ 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); @@ -516,13 +578,9 @@ 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; }
@@ -583,7 +641,6 @@ 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 @@ -624,9 +681,6 @@ 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); } } @@ -654,9 +708,6 @@ 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); } } diff --git a/net/batman-adv/send.h b/net/batman-adv/send.h index 7cecb75..999f786 100644 --- a/net/batman-adv/send.h +++ b/net/batman-adv/send.h @@ -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); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index fb445c5..89ea104 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1371,6 +1371,7 @@ 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; @@ -1383,6 +1384,7 @@ 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; };
/**