The following commit has been merged in the master branch: commit 390dcd48cd1a53a81b68a87d0188e6aacc54a199 Author: Linus Lüssing linus.luessing@c0d3.blue Date: Sun May 26 18:35:50 2019 +0200

batman-adv: mcast: avoid redundant multicast TT entries with bridges

When a bridge is added on top of bat0 we set the WANT_ALL_UNSNOOPABLES flag. Which means we sign up for all traffic for ff02::1/128 and 224.0.0.0/24.

When the node itself had IPv6 enabled or joined a group in 224.0.0.0/24 itself then so far this would result in a multicast TT entry which is redundant to the WANT_ALL_UNSNOOPABLES.

With this patch such redundant TT entries are avoided.

Signed-off-by: Linus Lüssing linus.luessing@c0d3.blue Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de

diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index ca9e2e67bdc6..d4e7474022e3 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -230,6 +230,10 @@ batadv_mcast_mla_softif_get_ipv4(struct net_device *dev,

for (pmc = rcu_dereference(in_dev->mc_list); pmc; pmc = rcu_dereference(pmc->next_rcu)) { + if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES && + ipv4_is_local_multicast(pmc->multiaddr)) + continue; + ip_eth_mc_map(pmc->multiaddr, mcast_addr);

if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list)) @@ -293,6 +297,10 @@ batadv_mcast_mla_softif_get_ipv6(struct net_device *dev, IPV6_ADDR_SCOPE_LINKLOCAL) continue;

+ if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES && + ipv6_addr_is_ll_all_nodes(&pmc6->mca_addr)) + continue; + ipv6_eth_mc_map(&pmc6->mca_addr, mcast_addr);

if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list)) @@ -413,9 +421,8 @@ static int batadv_mcast_mla_bridge_get(struct net_device *dev, struct batadv_mcast_mla_flags *flags) { struct list_head bridge_mcast_list = LIST_HEAD_INIT(bridge_mcast_list); - bool all_ipv4 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4; - bool all_ipv6 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6; struct br_ip_list *br_ip_entry, *tmp; + u8 tvlv_flags = flags->tvlv_flags; struct batadv_hw_addr *new; u8 mcast_addr[ETH_ALEN]; int ret; @@ -428,11 +435,25 @@ static int batadv_mcast_mla_bridge_get(struct net_device *dev, goto out;

list_for_each_entry(br_ip_entry, &bridge_mcast_list, list) { - if (all_ipv4 && br_ip_entry->addr.proto == htons(ETH_P_IP)) - continue; + if (br_ip_entry->addr.proto == htons(ETH_P_IP)) { + if (tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4) + continue;

- if (all_ipv6 && br_ip_entry->addr.proto == htons(ETH_P_IPV6)) - continue; + if (tvlv_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES && + ipv4_is_local_multicast(br_ip_entry->addr.u.ip4)) + continue; + } + +#if IS_ENABLED(CONFIG_IPV6) + if (br_ip_entry->addr.proto == htons(ETH_P_IPV6)) { + if (tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6) + continue; + + if (tvlv_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES && + ipv6_addr_is_ll_all_nodes(&br_ip_entry->addr.u.ip6)) + continue; + } +#endif

batadv_mcast_mla_br_addr_cpy(mcast_addr, &br_ip_entry->addr); if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list))