The goal of this serie is to be able to multicast netlink messages with an attribute that identify a peer netns. This is needed by the userland to interpret some informations contained in netlink messages (like IFLA_LINK value, but also some other attributes in case of x-netns netdevice (see also http://thread.gmane.org/gmane.linux.network/315933/focus=316064 and http://thread.gmane.org/gmane.linux.kernel.containers/28301/focus=4239)). Ids are stored in the parent user namespace. These ids are valid only inside this user namespace. The user can retrieve these ids via a new netlink messages, but only if peer netns are in the same user namespace. Patch 1/5 and 2/5 introduce the netlink API mechanism to exports these ids to the userland. Patch 3/5 and 4/5 shows an example of how to use these ids in rtnetlink messages. And patch 5/5 shows that the netlink messages can be symetric between a GET and a SET. iproute2 patches are available, I can send them on demand. Here is a small screenshot to show how it can be used by userland: $ ip netns add foo $ ip netns del foo $ ip netns $ touch /var/run/netns/init_net $ mount --bind /proc/1/ns/net /var/run/netns/init_net $ ip netns add foo $ ip netns foo (id: 3) init_net (id: 1) $ ip netns exec foo ip netns foo (id: 3) init_net (id: 1) $ ip netns exec foo ip link add ipip1 link-netnsid 1 type ipip remote 10.16.0.121 local 10.16.0.249 $ ip netns exec foo ip l ls ipip1 6: ipip1@NONE: <POINTOPOINT,NOARP> mtu 1480 qdisc noop state DOWN mode DEFAULT group default link/ipip 10.16.0.249 peer 10.16.0.121 link-netnsid 1 The parameter link-netnsid shows us where the interface sends and receives packets (and thus we know where encapsulated addresses are set). RFCv1 -> RFCv2: remove useless () ids are now stored in the user ns. It's possible to get an id for a peer netns only if the current netns and the peer netns have the same user ns parent. MAINTAINERS | 1 + include/linux/user_namespace.h | 4 ++ include/net/ip_tunnels.h | 1 + include/net/net_namespace.h | 12 +++++ include/net/rtnetlink.h | 2 + include/uapi/linux/Kbuild | 1 + include/uapi/linux/if_link.h | 1 + include/uapi/linux/netns.h | 29 ++++++++++ kernel/user_namespace.c | 6 +++ net/core/net_namespace.c | 119 ++++++++++++++++++++++++++++++++++++++++- net/core/rtnetlink.c | 47 ++++++++++++++-- net/ipv4/ip_gre.c | 2 + net/ipv4/ip_tunnel.c | 8 +++ net/ipv4/ip_vti.c | 1 + net/ipv4/ipip.c | 1 + net/ipv6/sit.c | 1 + net/netlink/genetlink.c | 4 ++ 17 files changed, 236 insertions(+), 4 deletions(-) Comments are welcome. Regards, Nicolas _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
