[PATCH 4.14 220/284] macvtap: advertise link netns via netlink

Greg Kroah-Hartman
2022-04-18T14:02:05Z

From: Sven Eckelmann <sven@narfation.org>

[ Upstream commit a02192151b7dbf855084c38dca380d77c7658353 ]

Assign rtnl_link_ops->get_link_net() callback so that IFLA_LINK_NETNSID is
added to rtnetlink messages. This fixes iproute2 which otherwise resolved
the link interface to an interface in the wrong namespace.

Test commands:

ip netns add nst
ip link add dummy0 type dummy
ip link add link macvtap0 link dummy0 type macvtap
ip link set macvtap0 netns nst
ip -netns nst link show macvtap0

Before:

10: macvtap0@gre0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 500
link/ether 5e:8f:ae:1d:60:50 brd ff:ff:ff:ff:ff:ff

After:

10: macvtap0@if2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 500
link/ether 5e:8f:ae:1d:60:50 brd ff:ff:ff:ff:ff:ff link-netnsid 0

Reported-by: Leonardo Mörlein <freifunk@irrelefant.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Link: https://lore.kernel.org/r/20220228003240.1337426-1-sven@narfation.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/macvtap.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index cba5cb3b849a..dc89019ca876 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -132,11 +132,17 @@ static void macvtap_setup(struct net_device *dev)
dev->tx_queue_len = TUN_READQ_SIZE;
}

+static struct net *macvtap_link_net(const struct net_device *dev)
+{
+ return dev_net(macvlan_dev_real_dev(dev));
+}
+
static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
.kind = "macvtap",
.setup = macvtap_setup,
.newlink = macvtap_newlink,
.dellink = macvtap_dellink,
+ .get_link_net = macvtap_link_net,
.priv_size = sizeof(struct macvtap_dev),
};

--
2.35.1