[B.A.T.M.A.N.] [PATCH 18/20] batman-adv: Still flood multicast packets we are not a receiver of

Linus Lüssing
2010-12-07T22:32:28Z

We may only optimize the multicast packet flow, if an mcast_mode has been
activated and if we are a multicast receiver of the same group. Otherwise
flood the multicast packet without optimizations.

This allows us to still flood multicast packets of protocols where it is
not easily possible for a multicast sender to be a multicast receiver of
the same group instead of dropping them (for instance IPv6 NDP).

This commit therefore also makes IPv6 usable again, if the
proact_tracking multicast mode has been activated.

Signed-off-by: Linus Lüssing <linus.luessing@saxnet.de>
---
multicast.c | 25 +++++++++++++++++++++++++
multicast.h | 1 +
soft-interface.c | 2 +-
3 files changed, 27 insertions(+), 1 deletions(-)

diff --git a/multicast.c b/multicast.c
index 042d392..1f84f7c 100644
--- a/multicast.c
+++ b/multicast.c
@@ -107,6 +107,31 @@ void mcast_tracker_reset(struct bat_priv *bat_priv)
start_mcast_tracker(bat_priv);
}

+inline int mcast_may_optimize(uint8_t *dest, struct net_device *soft_iface) {
+ MC_LIST *mc_entry;
+ unsigned long flags;
+ struct bat_priv *bat_priv = netdev_priv(soft_iface);
+ int mcast_mode = atomic_read(&bat_priv->mcast_mode);
+
+ if (mcast_mode != MCAST_MODE_PROACT_TRACKING)
+ return 0;
+
+ /* Still allow flooding of multicast packets of protocols where it is
+ * not easily possible for a multicast sender to be a multicast
+ * receiver of the same group (for instance IPv6 NDP) */
+ MC_LIST_LOCK(soft_iface, flags);
+ netdev_for_each_mc_addr(mc_entry, soft_iface) {
+ if (memcmp(dest, mc_entry->MC_LIST_ADDR, ETH_ALEN))
+ continue;
+
+ MC_LIST_UNLOCK(soft_iface, flags);
+ return 1;
+ }
+ MC_LIST_UNLOCK(soft_iface, flags);
+
+ return 0;
+}
+
static inline int get_remaining_timeout(
struct mcast_forw_nexthop_entry *nexthop_entry,
struct bat_priv *bat_priv)
diff --git a/multicast.h b/multicast.h
index 6dcf537..630a0ae 100644
--- a/multicast.h
+++ b/multicast.h
@@ -27,6 +27,7 @@ int mcast_tracker_interval_set(struct net_device *net_dev, char *buff,
int mcast_tracker_timeout_set(struct net_device *net_dev, char *buff,
size_t count);
void mcast_tracker_reset(struct bat_priv *bat_priv);
+int mcast_may_optimize(uint8_t *dest, struct net_device *soft_iface);
void route_mcast_tracker_packet(
struct mcast_tracker_packet *tracker_packet,
int tracker_packet_len, struct bat_priv *bat_priv);
diff --git a/soft-interface.c b/soft-interface.c
index 2a5a728..444028d 100644
--- a/soft-interface.c
+++ b/soft-interface.c
@@ -391,7 +391,7 @@ int interface_tx(struct sk_buff *skb, struct net_device *soft_iface)

if (is_broadcast_ether_addr(ethhdr->h_dest))
bcast_dst = true;
- else if (atomic_read(&bat_priv->mcast_mode) == MCAST_MODE_PROACT_TRACKING)
+ else if (mcast_may_optimize(ethhdr->h_dest, soft_iface))
mcast_dst = true;
else
bcast_dst = true;
--
1.7.1