Add new ndo to get the xmit slave of master device.
Caller should call dev_put() when it no longer works with
slave netdevice.
User can ask to get the xmit slave assume all the slaves can
transmit by set all_slaves arg to true.
Signed-off-by: Maor Gottlieb <maorg@xxxxxxxxxxxx>
---
include/linux/netdevice.h | 6 ++++++
net/core/dev.c | 30 ++++++++++++++++++++++++++++++
2 files changed, 36 insertions(+)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 130a668049ab..d1206f08e099 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1389,6 +1389,9 @@ struct net_device_ops {
struct netlink_ext_ack *extack);
int (*ndo_del_slave)(struct net_device *dev,
struct net_device *slave_dev);
+ struct net_device* (*ndo_get_xmit_slave)(struct net_device *dev,
+ struct sk_buff *skb,
+ bool all_slaves);
netdev_features_t (*ndo_fix_features)(struct net_device *dev,
netdev_features_t features);
int (*ndo_set_features)(struct net_device *dev,
@@ -2731,6 +2734,9 @@ void netdev_freemem(struct net_device *dev);
void synchronize_net(void);
int init_dummy_netdev(struct net_device *dev);
+struct net_device *netdev_get_xmit_slave(struct net_device *dev,
+ struct sk_buff *skb,
+ bool all_slaves);
struct net_device *dev_get_by_index(struct net *net, int ifindex);
struct net_device *__dev_get_by_index(struct net *net, int ifindex);
struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex);
diff --git a/net/core/dev.c b/net/core/dev.c
index 9c9e763bfe0e..294553551ba5 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -7785,6 +7785,36 @@ void netdev_bonding_info_change(struct net_device *dev,
}
EXPORT_SYMBOL(netdev_bonding_info_change);
+/**
+ * netdev_get_xmit_slave - Get the xmit slave of master device
+ * @skb: The packet
+ * @all_slaves: assume all the slaves are active
+ *
+ * This can be called from any context and does its own locking.
+ * The returned handle has the usage count incremented and the caller must
+ * use dev_put() to release it when it is no longer needed.
+ * %NULL is returned if no slave is found.
+ */
+
+struct net_device *netdev_get_xmit_slave(struct net_device *dev,
+ struct sk_buff *skb,
+ bool all_slaves)
+{
+ const struct net_device_ops *ops = dev->netdev_ops;
+ struct net_device *slave_dev;
+
+ if (!ops->ndo_get_xmit_slave)
+ return NULL;
+
+ rcu_read_lock();
+ slave_dev = ops->ndo_get_xmit_slave(dev, skb, all_slaves);
+ if (slave_dev)
+ dev_hold(slave_dev);
+ rcu_read_unlock();
+ return slave_dev;
+}
+EXPORT_SYMBOL(netdev_get_xmit_slave);
+
static void netdev_adjacent_add_links(struct net_device *dev)
{
struct netdev_adjacent *iter;
--
2.17.2
