tjh.dev
Merge branch 'netns'
Nicolas Dichtel says:
====================
netns: audit netdevice creation with IFLA_NET_NS_[PID|FD]
When one of these attributes is set, the netdevice is created into the netns
pointed by IFLA_NET_NS_[PID|FD] (see the call to rtnl_create_link() in
rtnl_newlink()). Let's call this netns the dest_net. After this creation, if the
newlink handler exists, it is called with a netns argument that points to the
netns where the netlink message has been received (called src_net in the code)
which is the link netns.
Hence, with one of these attributes, it's possible to create a x-netns
netdevice.
Here is the result of my code review:
- all ip tunnels (sit, ipip, ip6_tunnels, gre[tap][v6], ip_vti[6]) does not
really allows to use this feature: the netdevice is created in the dest_net
and the src_net is completely ignored in the newlink handler.
- VLAN properly handles this x-netns creation.
- bridge ignores src_net, which seems fine (NETIF_F_NETNS_LOCAL is set).
- CAIF subsystem is not clear for me (I don't know how it works), but it seems
to wrongly use src_net. Patch #1 tries to fix this, but it was done only by
code review (and only compile-tested), so please carefully review it. I may
miss something.
- HSR subsystem uses src_net to parse IFLA_HSR_SLAVE[1|2], but the netdevice has
the flag NETIF_F_NETNS_LOCAL, so the question is: does this netdevice really
supports x-netns? If not, the newlink handler should use the dest_net instead
of src_net, I can provide the patch.
- ieee802154 uses also src_net and does not have NETIF_F_NETNS_LOCAL. Same
question: does this netdevice really supports x-netns?
- bonding ignores src_net and flag NETIF_F_NETNS_LOCAL is set, ie x-netns is not
supported. Fine.
- CAN does not support rtnl/newlink, ok.
- ipvlan uses src_net and does not have NETIF_F_NETNS_LOCAL. After looking at
the code, it seems that this drivers support x-netns. Am I right?
- macvlan/macvtap uses src_net and seems to have x-netns support.
- team ignores src_net and has the flag NETIF_F_NETNS_LOCAL, ie x-netns is not
supported. Ok.
- veth uses src_net and have x-netns support ;-) Ok.
- VXLAN didn't properly handle this. The link netns (vxlan->net) is the src_net
and not dest_net (see patch #2). Note that it was already possible to create a
x-netns vxlan before the commit f01ec1c017de ("vxlan: add x-netns support")
but the nedevice remains broken.
To summarize:
- CAIF patch must be carefully reviewed
- for HSR, ieee802154, ipvlan: is x-netns supported?
====================
Signed-off-by: David S. Miller <davem@davemloft.net>