To be clarified, tap socket isn't created in netns currently because OVS doesn't have such info, current way is:
# Step 1, add tap interface into ovs bridge in root netns, tap socket is created at this point. # step 2, move tap interface to specified netns. So question, how do you get netns id from tap socket? Would you guys like to add netlink API for this in Linux kernel? I know you Redhat guys are familiar with rtnl. Can you two guys clearly explain how to implement the behavior you expect? -----邮件原件----- 发件人: Flavio Leitner [mailto:[email protected]] 发送时间: 2020年9月17日 19:59 收件人: Yi Yang (杨燚)-云服务集团 <[email protected]> 抄送: [email protected]; [email protected]; [email protected]; [email protected] 主题: Re: 答复: [ovs-dev] [PATCH v2 0/3] userspace: enable tap interface?statistics and status update support On Thu, Sep 17, 2020 at 01:05:22AM +0000, Yi Yang (杨燚)-云服务集团 wrote: > Aaron, any caller thread just binds it to netns on calling enter_netns, once > it has entered netns, it won't disappear, so exit_netns caller thread must be > current thread, once it exits netns, it returns back to original root netns, > at this point, this thread can disappear, not a question, isn't it? So I'm > not sure why you're saying it is unsafe. > > It is impossible to let Linux kernel provide that API with netns as > argument, although it is possible to do it theoretically, it is > impractical fantasy IMO :-) OVS already uses rtm_getlink to get that information, see netdev_linux_update_via_netlink(). What we need is to get netnsid from the tap socket. I also think that is a reasonable kernel API addition. See for example: a86bd14ec ("netlink: provide network namespace id from a msg."). fbl > > -----邮件原件----- > 发件人: dev [mailto:[email protected]] 代表 Aaron Conole > 发送时间: 2020年9月17日 0:38 > 收件人: [email protected] > 抄送: [email protected]; [email protected]; [email protected] > 主题: Re: [ovs-dev] [PATCH v2 0/3] userspace: enable tap interface > statistics and status update support > > [email protected] writes: > > > From: Yi Yang <[email protected]> > > > > OVS userspace datapath can't support tap interface statistics and > > status update, so users can't get these information by cmd > > "ovs-vsctl list interface tap1", the root cause of this issue is OVS > > doesn't know network namespace of tap interface. > > > > This patch series fixed this issue and make sure tap interface can > > show statistics and get status update. > > > > Yi Yang (3): > > Add netns option for tap interface in userspace datapath > > Fix tap interface statistics issue > > Fix tap interface status update issue in network namespace > > > > lib/dpif-netlink.c | 51 +++++ > > lib/dpif-netlink.h | 3 + > > lib/netdev-linux-private.h | 1 + > > lib/netdev-linux.c | 481 > > ++++++++++++++++++++++++++++++++++++++++----- > > lib/netlink-socket.c | 146 ++++++++++++++ > > lib/netlink-socket.h | 2 + > > lib/socket-util-unix.c | 37 ++++ > > lib/socket-util.h | 3 + > > 8 files changed, 675 insertions(+), 49 deletions(-) > > > > -- > > > > Changelog > > > > v1 -> v2: > > * Split pmd thread support to seperate patch series > > * Check enter_netns return error > > * Limit setns to network namespace only by CLONE_NEWNET > > Sorry, but more thinking about this I don't support this series going in. It > reassociates the thread with a netns that may disappear causing faults in the > middle of processing - I don't think it's safe. > > NAK. > > I think the correct solution is to add support in the kernel for > getting the netns/ifindex from the tap socket, and then use that to > query the statistics. This should be solved by using (or creating if > one doesn't > exist) a kernel API to do this query by getting the netns information and > using that to do these get operations. > > Maybe someone disagrees. > > _______________________________________________ > dev mailing list > [email protected] > https://mail.openvswitch.org/mailman/listinfo/ovs-dev -- fbl _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
