Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx> writes: > 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 of peer netns are set by userland via a new genl messages. These ids are > stored per netns and are local (ie only valid in the netns where they are set). > To avoid allocating an int for each peer netns, I use idr_for_each() to retrieve > the id of a peer netns. Note that it will be possible to add a table (struct net > -> id) later to optimize this lookup if needed. > > Patch 1/4 introduces the netlink API mechanism to set and get these ids. > Patch 2/4 and 3/4 implements an example of how to use these ids in rtnetlink > messages. And patch 4/4 shows that the netlink messages can be symetric between > a GET and a SET. > > iproute2 patches are available, I can send them on demand. A quick reply. I think this patchset is in the right general direction. There are some oddball details that seem odd/awkward to me such as using genetlink instead of rtnetlink to get and set the ids, and not having ids if they are not set (that feels like a maintenance/usability challenge). I would like to give your patches a deep review, but I won't be able to do that for a couple of weeks. I am deep in the process of moving, and will be mostly offline until about the Nov 11th. Eric > Here is a small screenshot to show how it can be used by userland. > > First, setup netns and required ids: > $ 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 exec foo ip netns set init_net 0 > $ ip netns > foo > init_net > $ ip netns exec foo ip netns > foo > init_net (id: 0) > > Now, add and display an ipip tunnel, with its link part in init_net (id 0 in > netns foo) and the netdevice in foo: > $ ip netns exec foo ip link add ipip1 link-netnsid 0 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 0 > > The parameter link-netnsid shows us where the interface sends and receives > packets (and thus we know where encapsulated addresses are set). > > RFCv3 -> v4: > rebase on net-next > add copyright text in the new netns.h file > > RFCv2 -> RFCv3: > ids are now defined by userland (via netlink). Ids are stored in each netns > (and they are local to this netns). > add get_link_net support for ip6 tunnels > netnsid is now a s32 instead of a u32 > > 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/net/ip6_tunnel.h | 1 + > include/net/ip_tunnels.h | 1 + > include/net/net_namespace.h | 5 ++ > include/net/rtnetlink.h | 2 + > include/uapi/linux/Kbuild | 1 + > include/uapi/linux/if_link.h | 1 + > include/uapi/linux/netns.h | 38 +++++++++ > net/core/net_namespace.c | 195 +++++++++++++++++++++++++++++++++++++++++++ > net/core/rtnetlink.c | 38 ++++++++- > 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/ip6_gre.c | 1 + > net/ipv6/ip6_tunnel.c | 9 ++ > net/ipv6/ip6_vti.c | 1 + > net/ipv6/sit.c | 1 + > net/netlink/genetlink.c | 4 + > 19 files changed, 308 insertions(+), 3 deletions(-) > > Comments are welcome. > > Regards, > Nicolas -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
