Re: [RFC v3 2/3] vxlan: add support for underlay in non-default VRF
From: David Ahern <hidden>
Date: 2018-11-21 01:27:26
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.
quoted hunk ↗ jump to hunk
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:
quoted hunk ↗ jump to hunk
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