On 11/20/18 7:23 AM, Alexis Bauvin wrote:
> Creating a VXLAN device with is underlay in the non-default VRF makes
> egress route lookup fail or incorrect since it will resolve in the
> default VRF, and ingress fail because the socket listens in the default
> VRF.
>
> This patch binds the underlying UDP tunnel socket to the l3mdev of the
> lower device of the VXLAN device. This will listen in the proper VRF and
> output traffic from said l3mdev, matching l3mdev routing rules and
> looking up the correct routing table.
>
> When the VXLAN device does not have a lower device, or the lower device
> is in the default VRF, the socket will not be bound to any interface,
> keeping the previous behaviour.
>
> The underlay l3mdev is deduced from the VXLAN lower device
> (IFLA_VXLAN_LINK).
>
> The l3mdev_master_upper_ifindex_by_index function has been added to
> l3mdev. Its goal is to fetch the effective l3mdev of an interface which
> is not a direct slave of said l3mdev. It handles the following example,
> properly resolving the l3mdev of eth0 to vrf-blue:
>
> +----------+ +---------+
> | | | |
> | vrf-blue | | vrf-red |
> | | | |
> +----+-----+ +----+----+
> | |
> | |
> +----+-----+ +----+----+
> | | | |
> | br-blue | | br-red |
> | | | |
> +----+-----+ +---+-+---+
> | | |
> | +-----+ +-----+
> | | |
> +----+-----+ +------+----+ +----+----+
> | | lower device | | | |
> | eth0 | <- - - - - - - | vxlan-red | | tap-red | (... more taps)
> | | | | | |
> +----------+ +-----------+ +---------+
same here. Very helpful diagram.
> diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
> index 27bd586b94b0..a3de08122269 100644
> --- a/drivers/net/vxlan.c
> +++ b/drivers/net/vxlan.c
The vxlan changes look ok to me. It would be good for someone who know
that code better than I do to review it.
Move the following l3mdev changes to a separate patch - introduce infra
changes separate from their use:
> diff --git a/include/net/l3mdev.h b/include/net/l3mdev.h
> index 3832099289c5..78fa0ac4613c 100644
> --- a/include/net/l3mdev.h
> +++ b/include/net/l3mdev.h
> @@ -101,6 +101,17 @@ struct net_device *l3mdev_master_dev_rcu(const struct
> net_device *_dev)
> return master;
> }
>
> +int l3mdev_master_upper_ifindex_by_index_rcu(struct net *net, int ifindex);
> +static inline
> +int l3mdev_master_upper_ifindex_by_index(struct net *net, int ifindex)
> +{
> + rcu_read_lock();
> + ifindex = l3mdev_master_upper_ifindex_by_index_rcu(net, ifindex);
> + rcu_read_unlock();
> +
> + return ifindex;
> +}
> +
> u32 l3mdev_fib_table_rcu(const struct net_device *dev);
> u32 l3mdev_fib_table_by_index(struct net *net, int ifindex);
> static inline u32 l3mdev_fib_table(const struct net_device *dev)
> @@ -207,6 +218,17 @@ static inline int l3mdev_master_ifindex_by_index(struct
> net *net, int ifindex)
> return 0;
> }
>
> +static inline
> +int l3mdev_master_upper_ifindex_by_index_rcu(struct net *net, int ifindex)
> +{
> + return 0;
> +}
> +static inline
> +int l3mdev_master_upper_ifindex_by_index(struct net *net, int ifindex)
> +{
> + return 0;
> +}
> +
> static inline
> struct net_device *l3mdev_master_dev_rcu(const struct net_device *dev)
> {
> diff --git a/net/l3mdev/l3mdev.c b/net/l3mdev/l3mdev.c
> index 8da86ceca33d..309dee76724e 100644
> --- a/net/l3mdev/l3mdev.c
> +++ b/net/l3mdev/l3mdev.c
> @@ -46,6 +46,24 @@ int l3mdev_master_ifindex_rcu(const struct net_device *dev)
> }
> EXPORT_SYMBOL_GPL(l3mdev_master_ifindex_rcu);
>
> +/**
> + * l3mdev_master_upper_ifindex_by_index - get index of upper l3 master
> + * device
> + * @net: network namespace for device index lookup
> + * @ifindex: targeted interface
> + */
> +int l3mdev_master_upper_ifindex_by_index_rcu(struct net *net, int ifindex)
> +{
> + struct net_device *dev;
> +
> + dev = dev_get_by_index_rcu(net, ifindex);
> + while (dev && !netif_is_l3_master(dev))
> + dev = netdev_master_upper_dev_get(dev);
> +
> + return dev ? dev->ifindex : 0;
> +}
> +EXPORT_SYMBOL_GPL(l3mdev_master_upper_ifindex_by_index_rcu);
> +
> /**
> * l3mdev_fib_table - get FIB table id associated with an L3
> * master interface
>
