From: Nicolas Dichtel <nicolas.dichtel@6wind.com>
To: Alexander Holler <holler@ahsoftware.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
netdev@vger.kernel.org, tgraf@suug.ch, davem@davemloft.net
Subject: Re: [PATCH net-next v2 0/7] netns: ease netlink use with a lot of netns
Date: Mon, 25 May 2015 09:45:25 +0200 [thread overview]
Message-ID: <5562D315.9070405@6wind.com> (raw)
In-Reply-To: <555F969B.3090706@ahsoftware.de>
Le 22/05/2015 22:50, Alexander Holler a écrit :
> Am 08.05.2015 um 14:02 schrieb Eric W. Biederman:
>>
>> So I am dense. I have read through the patches and I don't see where
>> you tag packets from other network namespaces with a network namespace
>> id.
>
> Me too,
>
> I've recently written a little tool called snetmanmon (source is
> available at github) to monitor and handle network related events
> by using rtnetlink.
>
> Having seen this patch series (thanks!), I've played with it.
>
> I've applied the patch series to v4.1-rc4.
>
> Maybe I'm using or holding it wrong, but I've some comments.
>
> First I think if NETLINK_LISTEN_ALL_NSID is enabled, a dump
> of the interfaces through RTM_GETLINK together with NLM_F_DUMP and
> NLM_F_REQUEST should return all interfaces of all reachable namespaces.
This option is only for 'listening', ie spontaneous notifications from the
kernel. It does nothing for request.
>
> Next, if NETLINK_LISTEN_ALL_NSID is enabled, I receive RTM_NEWLINK
> but without any indication of the namespace. E.g. if I do
> ip netns add netns1
> ip netns exec netns1 brctl addbr br0
> the RTM_NEWLINK for br0 (received in the root ns, not netns1) doesn't
> have the attribute IFLA_LINK_NETNSID.
nsid is sent through control message (see rcvmsg).
Try iproute2 branch net-next: 'ip monitor all-nsid'. It's an
example of how to use it.
>
> Same for the RTM_DELLINK msg if I call
> ip netns exec netns1 brctl delbr br0
> afterwards. So both netlink messages are looking like br0 was
> created in the root ns.
>
> Another problem seems to be with veth devices. E.g. if I do
> ip link add veth0 type veth peer name veth1
> ip link set veth1 netns netns1
> I receive
> RTM_NEWLINK for veth0 (no nsid)
> RTM_NEWLINK for veth1 (no nsid)
> RTM_DELLINK for veth1 (no nsid)
> RTM_NEWLINK for veth1 (with nsid 0)
> That looks ok, except the missing RTM_NEWLINK for lo in netns1, which
The nsid for netns1 in the current netns is allocated when the veth1 is moved to
netns1. At this time, lo is created since a long time, thus the kernel won't
send any notification.
Note, you can manually allocate it with 'ip netns set netns1 -1', but you
won't get any notifications for the loopback.
> was created together with the namespace. But if I now request a dump,
> I get
> RTM_NEWLINK for veth0 (with nsid 0)
> which looks like veth0 is part of nsid 0, and I get nothing for veth1.
The netlink message gives informations about veth1. With iproute2:
$ ip netns
netns1 (id: 0)
$ ip -d l ls veth0
9: veth0@if8: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT
group default qlen 1000
link/ether 72:36:c0:f4:35:64 brd ff:ff:ff:ff:ff:ff link-netnsid 0
promiscuity 0
veth addrgenmode eui64
Peer veth is the interface with ifindex 8 (@if8) in netns1 (link-netnsid 0).
To get informations about this interface, you need to dump it in netns1.
> Of course, that vlan device might be part of nsid 0 too (as veth1),
> but its part named veth0 is not part of that namespace. So the
> IFLA_LINK_NETNSID attribute received with the RTM_NEWLINK for veth0 through
> the dump is misleading.
Not sure to follow you. veth0 sits in the current netns (let's say init_net)
and veth1 in netns1.
So, when you dump veth0 in init_net, its link-netnsid is set to the id of
netns1 in init_net. And when you dump veth1 in netns1, it's link-netnsid is set
to the id of init_net in netns1.
>
> So it looks like either I missed something, I'm doing something wrong,
> or there still is some work todo to make NETLINK_LISTEN_ALL_NSID work
> like expected (or like my simple mind would expect it).
Having a patch that allows to perform request from a netns foo for a netns bar
is something doable, but much more complicated. And I think it requires more
thought. Let's see what will happen ;-)
>
> Thanks again for the patches, regards,
Thank you,
Regards,
Nicolas
next prev parent reply other threads:[~2015-05-25 7:45 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-06 9:58 [PATCH net-next 0/6] netns: ease netlink use with a lot of netns Nicolas Dichtel
2015-05-06 9:58 ` [PATCH net-next 1/6] netns: returns always an id in __peernet2id() Nicolas Dichtel
2015-05-06 11:19 ` Thomas Graf
2015-05-06 9:58 ` [PATCH net-next 2/6] netns: always provide the id to rtnl_net_fill() Nicolas Dichtel
2015-05-06 11:25 ` Thomas Graf
2015-05-06 9:58 ` [PATCH net-next 3/6] netns: rename peernet2id() to peernet2id_alloc() Nicolas Dichtel
2015-05-06 11:27 ` Thomas Graf
2015-05-06 9:58 ` [PATCH net-next 4/6] netns: notify new nsid outside __peernet2id() Nicolas Dichtel
2015-05-06 11:48 ` Thomas Graf
2015-05-06 13:39 ` Nicolas Dichtel
2015-05-06 9:58 ` [PATCH net-next 5/6] netns: use a spin_lock to protect nsid management Nicolas Dichtel
2015-05-06 12:23 ` Thomas Graf
2015-05-06 13:40 ` Nicolas Dichtel
2015-05-06 14:05 ` Thomas Graf
2015-05-06 9:58 ` [PATCH net-next 6/6] netlink: allow to listen "all" netns Nicolas Dichtel
2015-05-06 12:10 ` Thomas Graf
2015-05-06 13:42 ` Nicolas Dichtel
2015-05-07 9:02 ` [PATCH net-next v2 0/7] netns: ease netlink use with a lot of netns Nicolas Dichtel
2015-05-07 9:02 ` [PATCH net-next v2 1/7] netns: returns always an id in __peernet2id() Nicolas Dichtel
2015-05-07 9:02 ` [PATCH net-next v2 2/7] netns: always provide the id to rtnl_net_fill() Nicolas Dichtel
2015-05-07 9:02 ` [PATCH net-next v2 3/7] netns: rename peernet2id() to peernet2id_alloc() Nicolas Dichtel
2015-05-07 9:02 ` [PATCH net-next v2 4/7] netns: notify new nsid outside __peernet2id() Nicolas Dichtel
2015-05-07 11:47 ` Thomas Graf
2015-05-07 9:02 ` [PATCH net-next v2 5/7] netns: use a spin_lock to protect nsid management Nicolas Dichtel
2015-05-07 9:02 ` [PATCH net-next v2 6/7] netlink: rename private flags and states Nicolas Dichtel
2015-05-07 11:49 ` Thomas Graf
2015-05-07 9:02 ` [PATCH net-next v2 7/7] netlink: allow to listen "all" netns Nicolas Dichtel
2015-05-07 11:55 ` Thomas Graf
2015-05-08 12:02 ` [PATCH net-next v2 0/7] netns: ease netlink use with a lot of netns Eric W. Biederman
2015-05-09 21:07 ` Nicolas Dichtel
2015-05-22 20:50 ` Alexander Holler
2015-05-22 21:04 ` Cong Wang
2015-05-22 21:12 ` Alexander Holler
2015-05-22 21:29 ` Cong Wang
2015-05-22 21:46 ` Alexander Holler
2015-05-22 21:19 ` Eric W. Biederman
2015-05-22 21:30 ` Alexander Holler
2015-05-25 7:45 ` Nicolas Dichtel [this message]
2015-05-25 10:55 ` Alexander Holler
2015-05-25 13:09 ` Nicolas Dichtel
2015-05-26 10:53 ` Alexander Holler
2015-05-26 12:10 ` Nicolas Dichtel
2015-05-26 14:36 ` Alexander Holler
2015-05-29 5:57 ` Alexander Holler
2015-05-10 2:15 ` David Miller
2015-05-20 14:19 ` [PATCH iproute2-next 0/6] Allow to monitor 'all-nsid' with ip and ip xfrm Nicolas Dichtel
2015-05-20 14:19 ` [PATCH iproute2-next 1/6] include: update linux/netlink.h Nicolas Dichtel
2015-05-20 14:19 ` [PATCH iproute2-next 2/6] man: update ip monitor page Nicolas Dichtel
2015-05-20 14:19 ` [PATCH iproute2-next 3/6] libnetlink: introduce rtnl_listen_filter_t Nicolas Dichtel
2015-05-20 14:19 ` [PATCH iproute2-next 4/6] ipmonitor: introduce print_headers Nicolas Dichtel
2015-05-20 14:20 ` [PATCH iproute2-next 5/6] ipmonitor: allows to monitor in several netns Nicolas Dichtel
2015-05-20 14:20 ` [PATCH iproute2-next 6/6] xfrmmonitor: " Nicolas Dichtel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5562D315.9070405@6wind.com \
--to=nicolas.dichtel@6wind.com \
--cc=davem@davemloft.net \
--cc=ebiederm@xmission.com \
--cc=holler@ahsoftware.de \
--cc=netdev@vger.kernel.org \
--cc=tgraf@suug.ch \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).