[Devel] [PATCH RH7 1/2] net/vxlan: enable support and autoload in a container

[Pavel Tikhomirov]

vxlan is safe in CT as:

1) Udp multicast socket to connect to outer word sits in creation net-
namespace, and these socket can get packets only forwarded/routed
in creation ns.

2) Vxlan device is owned by second netns(could be same as first) as
any other network device, so same all packets come to it are from
the same ns.

3) Vxlans logic works through vxlan_net placed on creation netns,
vxlan_fdb and vxlan_rdst are per vxlan device. Thus entries can
not intersec with entries from host and other CTs.

* One problem I can see now is adding fdb with ifindex(index of
device to route packets from UDP socket through) after vxlan is
moved to second namespace in vxlan_fdb_parse we use second
namespace to check ifindex by device lookup, but in
vxlan_xmit_one->ip_route_output_key->...->__ip_route_output_key
we use first(creation) namespace to lookup device and probably
will fail. So all fdb configuration should go before moving to
ns. Same is in mainstream AFAICS.

https://jira.sw.ru/browse/PSBM-53629

Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>

---
 drivers/net/vxlan.c | 1 +
 kernel/kmod.c       | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index fd2516d..8e89665 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2367,6 +2367,7 @@ static void vxlan_setup(struct net_device *dev)
 
 	dev->vlan_features = dev->features;
 	dev->features |= NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
+	dev->features |= NETIF_F_VIRTUAL;
 	dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
 	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
 	dev->hw_features |= NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
diff --git a/kernel/kmod.c b/kernel/kmod.c
index e0ef148..63748d4 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -421,6 +421,7 @@ static const char * const ve0_allowed_mod[] = {
 	"ip_set_list:set",
 
 	"rtnl-link-dummy",
+	"rtnl-link-vxlan",
 };
 
 /*
-- 
2.7.4