diff options
Diffstat (limited to 'net/bridge')
| -rw-r--r-- | net/bridge/br_multicast.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index f234c48036c8..0703725527b3 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -4054,6 +4054,61 @@ unlock: } EXPORT_SYMBOL_GPL(br_multicast_has_querier_adjacent); +/** + * br_multicast_has_router_adjacent - Checks for a router behind a bridge port + * @dev: The bridge port adjacent to which to check for a multicast router + * @proto: The protocol family to check for: IGMP -> ETH_P_IP, MLD -> ETH_P_IPV6 + * + * Checks whether the given interface has a bridge on top and if so returns + * true if a multicast router is behind one of the other ports of this + * bridge. Otherwise returns false. + */ +bool br_multicast_has_router_adjacent(struct net_device *dev, int proto) +{ + struct net_bridge_port *port, *p; + bool ret = false; + + rcu_read_lock(); + port = br_port_get_check_rcu(dev); + if (!port) + goto unlock; + + switch (proto) { + case ETH_P_IP: + hlist_for_each_entry_rcu(p, &port->br->ip4_mc_router_list, + ip4_rlist) { + if (p == port) + continue; + + ret = true; + goto unlock; + } + break; +#if IS_ENABLED(CONFIG_IPV6) + case ETH_P_IPV6: + hlist_for_each_entry_rcu(p, &port->br->ip6_mc_router_list, + ip6_rlist) { + if (p == port) + continue; + + ret = true; + goto unlock; + } + break; +#endif + default: + /* when compiled without IPv6 support, be conservative and + * always assume presence of an IPv6 multicast router + */ + ret = true; + } + +unlock: + rcu_read_unlock(); + return ret; +} +EXPORT_SYMBOL_GPL(br_multicast_has_router_adjacent); + static void br_mcast_stats_add(struct bridge_mcast_stats __percpu *stats, const struct sk_buff *skb, u8 type, u8 dir) { |