+static ssize_t show_group_addr(struct class_device *cd, char *buf)
+{
+ struct net_bridge *br = to_bridge(cd);
+ return sprintf(buf, "%x:%x:%x:%x:%x:%x\n",
+ br->group_addr[0], br->group_addr[1],
+ br->group_addr[2], br->group_addr[3],
+ br->group_addr[4], br->group_addr[5]);
+}
+
+static ssize_t store_group_addr(struct class_device *cd, const char *buf,
+ size_t len)
+{
+ struct net_bridge *br = to_bridge(cd);
+ unsigned new_addr[6];
+ int i;
+
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+
+ if (sscanf(buf, "%x:%x:%x:%x:%x:%x",
+ &new_addr[0], &new_addr[1], &new_addr[2],
+ &new_addr[3], &new_addr[4], &new_addr[5]) != 6)
+ return -EINVAL;
+
+ /* Must be 01:80:c2:00:00:0X */
+ for (i = 0; i < 5; i++)
+ if (new_addr[i] != br_group_address[i])
+ return -EINVAL;
+
+ if (new_addr[5] & ~0xf)
+ return -EINVAL;
+
+ if (new_addr[5] == 1 /* 802.3x Pause address */
+ || new_addr[5] == 2 /* 802.3ad Slow protocols */
+ || new_addr[5] == 3) /* 802.1X PAE address */
+ return -EINVAL;
+
+ spin_lock_bh(&br->lock);
+ for (i = 0; i < 6; i++)
+ br->group_addr[i] = new_addr[i];
+ spin_unlock_bh(&br->lock);
+ return len;
+}
+
+static CLASS_DEVICE_ATTR(group_addr, S_IRUGO | S_IWUSR,
+ show_group_addr, store_group_addr);
+
+