| Message ID | 20210509194509.10849-12-linus.luessing@c0d3.blue |
|---|---|
| State | New |
| Headers | show |
| Series | net: bridge: split IPv4/v6 mc router state and export for batman-adv | expand |
On 09/05/2021 22:45, Linus Lüssing wrote: > To properly support routable multicast addresses in batman-adv in a > group-aware way, a batman-adv node needs to know if it serves multicast > routers. > > This adds a function to the bridge to export this so that batman-adv > can then make full use of the Multicast Router Discovery capability of > the bridge. > > Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> > --- > net/bridge/br_multicast.c | 58 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 58 insertions(+) > > diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c > index b625fd6..e963de5 100644 > --- a/net/bridge/br_multicast.c > +++ b/net/bridge/br_multicast.c > @@ -4061,6 +4061,64 @@ 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(); > + if (!netif_is_bridge_port(dev)) > + goto unlock; > + > + port = br_port_get_rcu(dev); You can combine both of netif_is_bridge_port and br_port_get_rcu() checks and use br_port_get_check_rcu(). Then you can also drop the port->br check. > + if (!port || !port->br) > + 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) > { >
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index b625fd6..e963de5 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -4061,6 +4061,64 @@ 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(); + if (!netif_is_bridge_port(dev)) + goto unlock; + + port = br_port_get_rcu(dev); + if (!port || !port->br) + 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) {
To properly support routable multicast addresses in batman-adv in a group-aware way, a batman-adv node needs to know if it serves multicast routers. This adds a function to the bridge to export this so that batman-adv can then make full use of the Multicast Router Discovery capability of the bridge. Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> --- net/bridge/br_multicast.c | 58 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+)