On 11/20/18 7:23 AM, Alexis Bauvin wrote:
> When underlay VRF changes, either because the lower device itself changed,
> or its VRF changed, this patch releases the current socket of the VXLAN
> device and recreates another one in the right VRF. This allows for
> on-the-fly change of the underlay VRF of a VXLAN device.
>
> Signed-off-by: Alexis Bauvin <abau...@scaleway.com>
> Reviewed-by: Amine Kherbouche <akherbou...@scaleway.com>
> Tested-by: Amine Kherbouche <akherbou...@scaleway.com>
> ---
> drivers/net/vxlan.c | 94 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 94 insertions(+)
>
> diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
> index a3de08122269..1e6ccad6df6a 100644
> --- a/drivers/net/vxlan.c
> +++ b/drivers/net/vxlan.c
> @@ -208,6 +208,18 @@ static inline struct vxlan_rdst
> *first_remote_rtnl(struct vxlan_fdb *fdb)
> return list_first_entry(&fdb->remotes, struct vxlan_rdst, list);
> }
>
> +static int vxlan_is_in_l3mdev_chain(struct net_device *chain,
> + struct net_device *dev)
> +{
> + if (!chain)
> + return 0;
> +
> + if (chain->ifindex == dev->ifindex)
> + return 1;
> + return vxlan_is_in_l3mdev_chain(netdev_master_upper_dev_get(chain),
> + dev);
> +}
This should return bool and true/false.
Also, why l3mdev in the name? None of the checks look at whether it is
an l3mdev master.
And again here, someone more familiar with the vxlan code should review it.
> +
> /* Find VXLAN socket based on network namespace, address family and UDP port
> * and enabled unshareable flags.
> */
> @@ -3720,6 +3732,33 @@ struct net_device *vxlan_dev_create(struct net *net,
> const char *name,
> }
> EXPORT_SYMBOL_GPL(vxlan_dev_create);
>
> +static int vxlan_reopen(struct vxlan_net *vn, struct vxlan_dev *vxlan)
> +{
> + int ret = 0;
> +
> + if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip) &&
> + !vxlan_group_used(vn, vxlan))
> + ret = vxlan_igmp_leave(vxlan);
> + vxlan_sock_release(vxlan);
> +
> + if (ret < 0)
> + return ret;
> +
> + ret = vxlan_sock_add(vxlan);
> + if (ret < 0)
> + return ret;
> +
> + if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip)) {
> + ret = vxlan_igmp_join(vxlan);
> + if (ret == -EADDRINUSE)
> + ret = 0;
> + if (ret)
> + vxlan_sock_release(vxlan);
> + }
> +
> + return ret;
> +}
> +
> static void vxlan_handle_lowerdev_unregister(struct vxlan_net *vn,
> struct net_device *dev)
> {
> @@ -3742,6 +3781,55 @@ static void vxlan_handle_lowerdev_unregister(struct
> vxlan_net *vn,
> unregister_netdevice_many(&list_kill);
> }
>
> +static void vxlan_handle_change_upper(struct vxlan_net *vn,
> + struct net_device *dev)
> +{
> + struct vxlan_dev *vxlan, *next;
> +
> + list_for_each_entry_safe(vxlan, next, &vn->vxlan_list, next) {
> + struct net_device *lower;
> + int err;
> +
> + lower = __dev_get_by_index(vxlan->net,
> + vxlan->cfg.remote_ifindex);
> + if (!vxlan_is_in_l3mdev_chain(lower, dev))
> + continue;
> +
> + err = vxlan_reopen(vn, vxlan);
> + if (err < 0)
> + netdev_err(vxlan->dev, "Failed to reopen socket: %d\n",
> + err);
> + }
> +}
> +
> +static void vxlan_handle_change(struct vxlan_net *vn, struct net_device *dev)
> +{
> + struct vxlan_dev *vxlan = netdev_priv(dev);
> + struct vxlan_sock *sock;
> + int l3mdev_index;
> +
> +#if IS_ENABLED(CONFIG_IPV6)
> + bool metadata = vxlan->cfg.flags & VXLAN_F_COLLECT_METADATA;
> + bool ipv6 = vxlan->cfg.flags & VXLAN_F_IPV6 || metadata;
> +
> + sock = ipv6 ? rcu_dereference(vxlan->vn6_sock)
> + : rcu_dereference(vxlan->vn4_sock);
> +#else
> + sock = rcu_dereference(vxlan->vn4_sock);
> +#endif
> +
> + l3mdev_index =
> + l3mdev_master_upper_ifindex_by_index(vxlan->net,
> + vxlan->cfg.remote_ifindex);
> + if (sock->sock->sk->sk_bound_dev_if != l3mdev_index) {
> + int ret = vxlan_reopen(vn, vxlan);
> +
> + if (ret < 0)
> + netdev_err(vxlan->dev, "Failed to reopen socket: %d\n",
> + ret);
> + }
> +}
> +
> static int vxlan_netdevice_event(struct notifier_block *unused,
> unsigned long event, void *ptr)
> {
> @@ -3756,6 +3844,12 @@ static int vxlan_netdevice_event(struct notifier_block
> *unused,
> } else if (event == NETDEV_UDP_TUNNEL_PUSH_INFO ||
> event == NETDEV_UDP_TUNNEL_DROP_INFO) {
> vxlan_offload_rx_ports(dev, event ==
> NETDEV_UDP_TUNNEL_PUSH_INFO);
> + } else if (event == NETDEV_CHANGEUPPER) {
> + vxlan_handle_change_upper(vn, dev);
> + } else if (event == NETDEV_CHANGE) {
> + if (dev->rtnl_link_ops &&
> + !strcmp(dev->rtnl_link_ops->kind, vxlan_link_ops.kind))
> + vxlan_handle_change(vn, dev);
> }
>
> return NOTIFY_DONE;
>
