From 3111beed0d595d26551afb607c9812fe49da2ead Mon Sep 17 00:00:00 2001 From: Linus Lüssing Date: Sun, 7 Aug 2016 12:34:19 +0200 Subject: batman-adv: Simple (re)broadcast avoidance MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit With this patch, (re)broadcasting on a specific interfaces is avoided: * No neighbor: There is no need to broadcast on an interface if there is no node behind it. * Single neighbor is source: If there is just one neighbor on an interface and if this neighbor is the one we actually got this broadcast packet from, then we do not need to echo it back. * Single neighbor is originator: If there is just one neighbor on an interface and if this neighbor is the originator of this broadcast packet, then we do not need to echo it back. Goodies for BATMAN V: ("Upgrade your BATMAN IV network to V now to get these for free!") Thanks to the split of OGMv1 into two packet types, OGMv2 and ELP that is, we can now apply the same optimizations stated above to OGMv2 packets, too. Furthermore, with BATMAN V, rebroadcasts can be reduced in certain multi interface cases, too, where BATMAN IV cannot. This is thanks to the removal of the "secondary interface originator" concept in BATMAN V. Signed-off-by: Linus Lüssing Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich --- net/batman-adv/send.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 54 insertions(+), 1 deletion(-) (limited to 'net/batman-adv/send.c') diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index be3f6d77f961..d9bbb00150a8 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -549,6 +549,7 @@ _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, * @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 * * add a broadcast packet to the queue and setup timers. broadcast packets * are sent multiple times to increase probability for being received. @@ -560,7 +561,8 @@ _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, */ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, const struct sk_buff *skb, - unsigned long delay) + unsigned long delay, + bool own_packet) { struct batadv_hard_iface *primary_if; struct batadv_forw_packet *forw_packet; @@ -587,6 +589,7 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, bcast_packet->ttl--; forw_packet->skb = newskb; + forw_packet->own = own_packet; INIT_DELAYED_WORK(&forw_packet->delayed_work, batadv_send_outstanding_bcast_packet); @@ -603,11 +606,16 @@ err: static void batadv_send_outstanding_bcast_packet(struct work_struct *work) { struct batadv_hard_iface *hard_iface; + struct batadv_hardif_neigh_node *neigh_node; struct delayed_work *delayed_work; struct batadv_forw_packet *forw_packet; + struct batadv_bcast_packet *bcast_packet; struct sk_buff *skb1; struct net_device *soft_iface; struct batadv_priv *bat_priv; + u8 *neigh_addr; + u8 *orig_neigh; + int ret = 0; delayed_work = to_delayed_work(work); forw_packet = container_of(delayed_work, struct batadv_forw_packet, @@ -625,6 +633,8 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work) if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) goto out; + bcast_packet = (struct batadv_bcast_packet *)forw_packet->skb->data; + /* rebroadcast packet */ rcu_read_lock(); list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { @@ -634,6 +644,49 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work) if (forw_packet->num_packets >= hard_iface->num_bcasts) continue; + if (forw_packet->own) { + neigh_node = NULL; + } else { + neigh_addr = eth_hdr(forw_packet->skb)->h_source; + neigh_node = batadv_hardif_neigh_get(hard_iface, + neigh_addr); + } + + orig_neigh = neigh_node ? neigh_node->orig : NULL; + + ret = batadv_hardif_no_broadcast(hard_iface, bcast_packet->orig, + orig_neigh); + + if (ret) { + char *type; + + switch (ret) { + case BATADV_HARDIF_BCAST_NORECIPIENT: + type = "no neighbor"; + break; + case BATADV_HARDIF_BCAST_DUPFWD: + type = "single neighbor is source"; + break; + case BATADV_HARDIF_BCAST_DUPORIG: + type = "single neighbor is originator"; + break; + default: + type = "unknown"; + } + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "BCAST packet from orig %pM on %s surpressed: %s\n", + bcast_packet->orig, + hard_iface->net_dev->name, type); + + if (neigh_node) + batadv_hardif_neigh_put(neigh_node); + + continue; + } + + if (neigh_node) + batadv_hardif_neigh_put(neigh_node); + if (!kref_get_unless_zero(&hard_iface->refcount)) continue; -- cgit v1.2.3