From: Nicolas Dichtel <nicolas.dichtel@6wind•com>
To: David Laight <David.Laight@ACULAB•COM>,
David Miller <davem@davemloft•net>,
jiri@resnulli•us, vyasevich@gmail•com, netdev@vger•kernel.org,
kuznet@ms2•inr.ac.ru, jmorris@namei•org, yoshfuji@linux-ipv6•org,
kaber@trash•net, thaller@redhat•com, stephen@networkplumber•org
Subject: Re: [patch net-next] ipv6: allow userspace to create address with IFLA_F_TEMPORARY flag
Date: Tue, 05 Nov 2013 18:02:17 +0100 [thread overview]
Message-ID: <52792499.3030201@6wind.com> (raw)
In-Reply-To: <20131029124010.GA15762@order.stressinduktion.org>
Le 29/10/2013 13:40, Hannes Frederic Sowa a écrit :
> On Tue, Oct 29, 2013 at 09:37:06AM -0000, David Laight wrote:
>>> Note that you don't even need to put the DHCP protocol core into the
>>> kernel to fix the promiscuous problem. You just have to use the
>>> current kernel interfaces correctly.
>>>
>>> It used to be the case a very long time ago that you couldn't even
>>> receive broadcast UDP datagrams on a socket until an address was
>>> configured on it.
>>>
>>> So everyone turns on promiscuous mode and uses RAW sockets or
>>> AF_PACKET.
>>>
>>> Stupid? yes.
>>
>> Not only that, but the dhcp client could use a normal UDP socket
>> to keep the lease renewed - I suspect it has only ever needed
>> to use the BPF interface (I didn't think it set promiscuous)
>> when acquiring the initial lease.
>
> Yes, this is a very unfortunate situation. From my experience it is not that
> easy to get a patch merged into isc-dhcp.
>
> It seems not that invasive to switch from af_packet to an udp socket with
> SO_BROADCAST set.
If I remember well, another problem is to be able to send these packets with
0.0.0.0 when another IP address is available on the system:
RFC2131
4.1 Constructing and sending DHCP messages
...
DHCP messages broadcast by a client prior to that client obtaining
its IP address must have the source address field in the IP header
set to 0.
We made a patch (never proposed upstream) to add a socket option to keep
this 0.0.0.0 address.
If people are interested, I can try to port it on net-next.
Nicolas
next prev parent reply other threads:[~2013-11-05 17:02 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-24 13:45 [patch net-next] ipv6: allow userspace to create address with IFLA_F_TEMPORARY flag Jiri Pirko
2013-10-24 13:48 ` [patch iproute2] allow to create temporary addresses Jiri Pirko
2013-10-24 14:02 ` [patch net-next] ipv6: allow userspace to create address with IFLA_F_TEMPORARY flag Hannes Frederic Sowa
2013-10-24 16:59 ` Jiri Pirko
2013-10-25 10:05 ` Vladislav Yasevich
2013-10-25 20:12 ` Hannes Frederic Sowa
2013-10-25 23:05 ` Vladislav Yasevich
2013-10-27 13:29 ` Jiri Pirko
2013-10-27 16:48 ` Hannes Frederic Sowa
2013-10-28 13:56 ` Vladislav Yasevich
2013-10-28 21:17 ` David Miller
2013-10-28 23:16 ` Dan Williams
2013-10-28 23:23 ` Dan Williams
2013-10-29 0:12 ` David Miller
2013-10-28 23:48 ` Hannes Frederic Sowa
2013-10-29 14:31 ` Dan Williams
2013-10-29 14:38 ` Hannes Frederic Sowa
2013-10-29 17:21 ` Dan Williams
2013-10-29 16:58 ` Vlad Yasevich
2013-10-29 17:15 ` Dan Williams
2013-10-29 0:08 ` David Miller
2013-10-29 0:13 ` Hannes Frederic Sowa
2013-10-29 0:46 ` David Miller
2013-10-28 23:31 ` Hannes Frederic Sowa
2013-10-29 0:43 ` David Miller
2013-10-29 9:37 ` David Laight
2013-10-29 12:40 ` Hannes Frederic Sowa
2013-10-29 13:09 ` Eric Dumazet
2013-10-29 13:11 ` Hannes Frederic Sowa
2013-10-29 19:58 ` David Miller
2013-11-01 21:28 ` Hannes Frederic Sowa
2013-11-05 17:02 ` Nicolas Dichtel [this message]
2013-11-05 17:12 ` David Laight
2013-11-05 21:11 ` Hannes Frederic Sowa
2013-11-06 9:23 ` David Laight
2013-11-06 12:03 ` Hannes Frederic Sowa
2013-11-05 20:57 ` Hannes Frederic Sowa
2013-11-06 8:11 ` Nicolas Dichtel
2013-11-09 0:54 ` [RFC PATCH net-next 1/2] ipv4: fix wildcard search with inet_confirm_addr() Nicolas Dichtel
2013-11-09 0:54 ` [RFC PATCH net-next 2/2] udp: add sk opt to allow sending pkt with src 0.0.0.0 Nicolas Dichtel
2013-11-09 14:46 ` Julian Anastasov
2013-11-12 8:59 ` Nicolas Dichtel
2013-11-11 5:18 ` David Miller
2013-11-14 13:05 ` Nicolas Dichtel
2013-11-14 19:57 ` David Miller
2013-11-18 9:15 ` Nicolas Dichtel
2013-11-14 14:31 ` Hannes Frederic Sowa
2013-11-14 20:00 ` David Miller
2013-10-29 19:44 ` [patch net-next] ipv6: allow userspace to create address with IFLA_F_TEMPORARY flag David Miller
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=52792499.3030201@6wind.com \
--to=nicolas.dichtel@6wind$(echo .)com \
--cc=David.Laight@ACULAB$(echo .)COM \
--cc=davem@davemloft$(echo .)net \
--cc=jiri@resnulli$(echo .)us \
--cc=jmorris@namei$(echo .)org \
--cc=kaber@trash$(echo .)net \
--cc=kuznet@ms2$(echo .)inr.ac.ru \
--cc=netdev@vger$(echo .)kernel.org \
--cc=stephen@networkplumber$(echo .)org \
--cc=thaller@redhat$(echo .)com \
--cc=vyasevich@gmail$(echo .)com \
--cc=yoshfuji@linux-ipv6$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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