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Message-Id: <1470992215-11009-16-git-send-email-sw@simonwunderlich.de>
Date: Fri, 12 Aug 2016 10:56:51 +0200
From: Simon Wunderlich <sw@...onwunderlich.de>
To: davem@...emloft.net
Cc: netdev@...r.kernel.org, b.a.t.m.a.n@...ts.open-mesh.org,
Linus Lüssing <linus.luessing@...3.blue>,
Marek Lindner <mareklindner@...mailbox.ch>,
Sven Eckelmann <sven@...fation.org>,
Simon Wunderlich <sw@...onwunderlich.de>
Subject: [PATCH 15/19] batman-adv: Introduce forward packet creation helper
From: Linus Lüssing <linus.luessing@...3.blue>
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@...3.blue>
Signed-off-by: Marek Lindner <mareklindner@...mailbox.ch>
Signed-off-by: Sven Eckelmann <sven@...fation.org>
Signed-off-by: Simon Wunderlich <sw@...onwunderlich.de>
---
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 57e0af9..a40cdf2 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);
}
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index 6191159..33d8bd1 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);
}
}
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 54710c7..72806a3 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -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;
};
/**
--
2.8.1
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