bridge: add sysfs hook to flush forwarding table

The RSTP daemon needs to be able to flush all dynamic forwarding
entries in the case of topology change.

This is a temporary interface. It will change to a netlink interface
before RSTP daemon is officially released.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
index 01a22ad0cc75..6cc5cfe665cd 100644
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -309,6 +309,19 @@ static ssize_t store_group_addr(struct device *d,
 static DEVICE_ATTR(group_addr, S_IRUGO | S_IWUSR,
                    show_group_addr, store_group_addr);
 
+static ssize_t store_flush(struct device *d,
+                           struct device_attribute *attr,
+                           const char *buf, size_t len)
+{
+        struct net_bridge *br = to_bridge(d);
+
+        if (!capable(CAP_NET_ADMIN))
+                return -EPERM;
+
+        br_fdb_flush(br);
+        return len;
+}
+static DEVICE_ATTR(flush, S_IWUSR, NULL, store_flush);
 
 static struct attribute *bridge_attrs[] = {
         &dev_attr_forward_delay.attr,
@@ -328,6 +341,7 @@ static struct attribute *bridge_attrs[] = {
         &dev_attr_topology_change_timer.attr,
         &dev_attr_gc_timer.attr,
         &dev_attr_group_addr.attr,
+        &dev_attr_flush.attr,
         NULL
 };