[B.A.T.M.A.N.] [PATCHv2 net-next 3/4] bridge: add export of multicast database adjacent to net_dev

Linus Lüssing
2014-05-25T05:03:24Z

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.

Adding bridge support to the batman-adv multicast optimization requires
batman-adv knowing about the existence of bridged-in multicast
listeners to be able to reliably serve them with multicast packets.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
---
include/linux/if_bridge.h | 18 ++++++++++++++
net/bridge/br_multicast.c | 58 +++++++++++++++++++++++++++++++++++++++++++++
net/bridge/br_private.h | 12 ----------
3 files changed, 76 insertions(+), 12 deletions(-)

diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
index 1085ffe..44d6eb0 100644
--- a/include/linux/if_bridge.h
+++ b/include/linux/if_bridge.h
@@ -16,9 +16,27 @@
#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;
+ __u16 vid;
+};
+
+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;
+int br_multicast_list_adjacent(struct net_device *dev,
+ struct list_head *br_ip_list);

#endif
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index b3f17c9..807e535 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>
@@ -2141,3 +2142,60 @@ 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;
+ 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, &port->mglist, mglist) {
+ entry = kmalloc(sizeof(*entry), 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 bc1803b..cb704a6 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -54,18 +54,6 @@ struct mac_addr
unsigned char addr[ETH_ALEN];
};

-struct br_ip
-{
- union {
- __be32 ip4;
-#if IS_ENABLED(CONFIG_IPV6)
- struct in6_addr ip6;
-#endif
- } u;
- __be16 proto;
- __u16 vid;
-};
-
#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
/* our own querier */
struct bridge_mcast_own_query {
--
1.7.10.4