From: Alexander Holler <holler@ahsoftware.de>
To: nicolas.dichtel@6wind.com
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: Tue, 26 May 2015 12:53:11 +0200 [thread overview]
Message-ID: <55645097.5000509@ahsoftware.de> (raw)
In-Reply-To: <55631F22.90903@6wind.com>
Am 25.05.2015 um 15:09 schrieb Nicolas Dichtel:
> Le 25/05/2015 12:55, Alexander Holler a écrit :
>> Am 25.05.2015 um 09:45 schrieb Nicolas Dichtel:
>>> Le 22/05/2015 22:50, Alexander Holler a écrit :
>>
>>>> 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.
>>
>> The problem is that you need informations about the affected
>> interfaces. E.g. if
>> you receive an NEWADDR or NEWROUTE for some interface (indicated by
>> the index of
>> the interface) in a(nother) namespace, how do you get informations
>> about that
>> interface, if not by a dump which includes the interfaces of these
>> namespaces
>> too? Without knowledge about the interface, these messages are not
>> very usable. ;)
> Yes, this is the right things.
>
> Usually, a daemon opens a socket to listen netlink event. Then, it opens
> another netlink socket to dump the configuration (interfaces, addresses,
> routes, etc.) and fill its internal structures. Starting from that
> point, for
> most of configuration parameters, it doesn't need anymore to do dumps
> and thus
> it can close the second socket. This allows your daemon to have only one
> socket
> to monitor a set a netns.
> Look at iproute for example, it starts by dumping all interfaces before
> executing the specified command.
Hmm, sounds like we're talking in different rooms about the same thing
in regard to the dump. ;)
I just wanted to explain why I think this series misses the (extended)
dump which includes all interfaces (those of other namespaces too).
How does one use NETLINK_LISTEN_ALL_NSID without beeing able to dump all
the interfaces of namespaces your patch series might send messages for?
The only way I currently see, is to start the listening part before any
namespace is created. Doing so, it can fill it's internal structures
with the RTM_NEWLINK messages (besides that missing one for lo). But how
do you get these RTM_NEWLINK messages for already created namespaces and
their interfaces, if not by a dump?
Regards,
Alexander Holler
next prev parent reply other threads:[~2015-05-26 10:54 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
2015-05-25 10:55 ` Alexander Holler
2015-05-25 13:09 ` Nicolas Dichtel
2015-05-26 10:53 ` Alexander Holler [this message]
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
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