With this new, exported function br_multicast_list_adjacent(net_dev) a list of IPv4/6 addresses is returned. This list contains all multicast addresses sensed by the bridge multicast snooping feature on all bridge ports of the bridge interface of net_dev, excluding addresses from the specified net_device itself.
A multicast optimization currently implemented for batman-adv requires this data. Signed-off-by: Linus Lüssing <linus.luess...@web.de> --- include/linux/if_bridge.h | 17 +++++++++++++ net/bridge/br_multicast.c | 59 +++++++++++++++++++++++++++++++++++++++++++++ net/bridge/br_private.h | 11 --------- 3 files changed, 76 insertions(+), 11 deletions(-) diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h index 1085ffe..86d71a8 100644 --- a/include/linux/if_bridge.h +++ b/include/linux/if_bridge.h @@ -16,9 +16,26 @@ #include <linux/netdevice.h> #include <uapi/linux/if_bridge.h> +struct br_ip { + union { + __be32 ip4; +#if IS_ENABLED(CONFIG_IPV6) + struct in6_addr ip6; +#endif + } u; + __be16 proto; +}; + +struct br_ip_list { + struct list_head list; + struct br_ip addr; +}; + extern void brioctl_set(int (*ioctl_hook)(struct net *, unsigned int, void __user *)); typedef int br_should_route_hook_t(struct sk_buff *skb); extern br_should_route_hook_t __rcu *br_should_route_hook; +extern int br_multicast_list_adjacent(struct net_device *net_dev, + struct list_head *br_ip_list); #endif diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 6d6f265..773a8c2 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -11,6 +11,7 @@ */ #include <linux/err.h> +#include <linux/export.h> #include <linux/if_ether.h> #include <linux/igmp.h> #include <linux/jhash.h> @@ -1846,3 +1847,61 @@ unlock: return err; } + +/** + * br_multicast_list_adjacent - Returns snooped multicast addresses + * @dev: The bridge port adjacent to which to retrieve addresses + * @br_ip_list: The list to store found, snooped multicast IP addresses in + * + * Creates a list of IP addresses (struct br_ip_list) sensed by the multicast + * snooping feature on all bridge ports of dev's bridge device, excluding + * the addresses from dev itself. + * + * Returns the number of items added to br_ip_list. + * + * Notes: + * - br_ip_list needs to be initialized by caller + * - br_ip_list might contain duplicates in the end + * (needs to be taken care of by caller) + * - br_ip_list needs to be freed by caller + */ +int br_multicast_list_adjacent(struct net_device *dev, + struct list_head *br_ip_list) +{ + struct net_bridge *br; + struct net_bridge_port *port; + struct net_bridge_port_group *group; + struct br_ip_list *entry; + struct hlist_node *p; + int count = 0; + + rcu_read_lock(); + if (!br_ip_list || !br_port_exists(dev)) + goto unlock; + + port = br_port_get_rcu(dev); + if (!port || !port->br) + goto unlock; + + br = port->br; + + list_for_each_entry_rcu(port, &br->port_list, list) { + if (!port->dev || port->dev == dev) + continue; + + hlist_for_each_entry_rcu(group, p, &port->mglist, mglist) { + entry = kmalloc(sizeof(struct br_ip_list), GFP_ATOMIC); + if (!entry) + goto unlock; + + entry->addr = group->addr; + list_add(&entry->list, br_ip_list); + count++; + } + } + +unlock: + rcu_read_unlock(); + return count; +} +EXPORT_SYMBOL(br_multicast_list_adjacent); diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 711094a..edf3fd8 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -52,17 +52,6 @@ struct mac_addr unsigned char addr[6]; }; -struct br_ip -{ - union { - __be32 ip4; -#if IS_ENABLED(CONFIG_IPV6) - struct in6_addr ip6; -#endif - } u; - __be16 proto; -}; - struct net_bridge_fdb_entry { struct hlist_node hlist; -- 1.7.10.4