Currently we schedule a broadcast packet like:
3x: [ [(re-)queue] --> for(hard-if): maybe-transmit ]
The intention of queueing a broadcast packet multiple times is to
increase robustness for wireless interfaces. However on interfaces
which we only broadcast on once the queueing induces an unnecessary
penalty. This patch restructures the queueing to be performed on a per
interface basis:
for(hard-if):
- transmit
- if wireless: [queue] --> transmit --> [requeue] --> transmit
Next to the performance benefits on non-wireless interfaces this
should also make it easier to apply alternative strategies for
transmissions on wireless interfaces in the future (for instance sending
via unicast transmissions on wireless interfaces, without queueing in
batman-adv, if appropriate).
Signed-off-by: Linus Lüssing
---
Changelog v2:
* removed the other two patches from the patchset for now, only
the broadcast queueing cleanup to start with
* fixed spelling of "unnecessary" in commit message (thanks Sven)
* removed now superflous kerneldoc for hard_iface in
batadv_forw_packet_bcasts_left() (thanks Sven)
* removed delay check for queued (re)broadcasts in
batadv_forw_bcast_packet_if(): the only case where a delay is set
for this function is for a delayed, DAT fallback ARP Request from
this node, then however num_bcasts will be >=1, too, and the fallback
ARP Request will be scheduled anyway
---
net/batman-adv/main.h | 1 -
net/batman-adv/routing.c| 9 +-
net/batman-adv/send.c | 392 ++--
net/batman-adv/send.h | 12 +-
net/batman-adv/soft-interface.c | 12 +-
5 files changed, 288 insertions(+), 138 deletions(-)
diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index 8f0102b7..baa9fcbe 100644
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -88,7 +88,6 @@
/* number of packets to send for broadcasts on different interface types */
#define BATADV_NUM_BCASTS_DEFAULT 1
#define BATADV_NUM_BCASTS_WIRELESS 3
-#define BATADV_NUM_BCASTS_MAX 3
/* length of the single packet used by the TP meter */
#define BATADV_TP_PACKET_LEN ETH_DATA_LEN
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 40f5cffd..bb9e93e3 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -1182,9 +1182,9 @@ int batadv_recv_bcast_packet(struct sk_buff *skb,
struct batadv_bcast_packet *bcast_packet;
struct ethhdr *ethhdr;
int hdr_size = sizeof(*bcast_packet);
- int ret = NET_RX_DROP;
s32 seq_diff;
u32 seqno;
+ int ret;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, hdr_size)))
@@ -1210,7 +1210,7 @@ int batadv_recv_bcast_packet(struct sk_buff *skb,
if (batadv_is_my_mac(bat_priv, bcast_packet->orig))
goto free_skb;
- if (bcast_packet->ttl < 2)
+ if (bcast_packet->ttl-- < 2)
goto free_skb;
orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);
@@ -1249,7 +1249,9 @@ int batadv_recv_bcast_packet(struct sk_buff *skb,
batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet));
/* rebroadcast packet */
- batadv_add_bcast_packet_to_list(bat_priv, skb, 1, false);
+ ret = batadv_forw_bcast_packet(bat_priv, skb, 0, false);
+ if (ret == NETDEV_TX_BUSY)
+ goto free_skb;
/* don't hand the broadcast up if it is from an originator
* from the same backbone.
@@ -1275,6 +1277,7 @@ int batadv_recv_bcast_packet(struct sk_buff *skb,
spin_unlock_bh(_node->bcast_seqno_lock);
free_skb:
kfree_skb(skb);
+ ret = NET_RX_DROP;
out:
if (orig_node)
batadv_orig_node_put(orig_node);
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index 157abe92..1db6b217 100644
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -737,57 +737,52 @@ void batadv_forw_packet_ogmv1_queue(struct batadv_priv
*bat_priv,
}
/**
- * batadv_add_bcast_packet_to_list() - queue broadcast packet for multiple
sends
+ * batadv_forw_bcast_packet_to_list() - queue broadcast packet for
transmissions
* @bat_priv: the bat priv with all the soft interface information
* @skb: broadcast packet to add
* @delay: number of jiffies to wait before sending
* @own_packet: true if it is a self-generated broadcast packet
+ * @if_in: the interface where the packet was received on
+ * @if_out: the outgoing interface to queue on
*
- * add a broadcast packet to the queue and setup timers. broadcast packets
+ * Adds a broadcast packet to the queue and sets up timers. Broadcast packets
* are sent multiple times to increase probability for being received.
*
- * The skb is not consumed, so the caller should make sure that the
- * skb is freed.
+ * This call clones the given skb, hence the caller needs to take into
+ * account that the data segment of the original skb
