From: "YOSHIFUJI Hideaki/吉藤英明" <hideaki.yoshifuji@miraclelinux•com>
To: Ulf Samuelsson <ulf.samuelsson@ericsson•com>,
yzhu1 <Yanjun.Zhu@windriver•com>,
brian.haley@hp•com, davem@davemloft•net,
alexandre.dietsch@windriver•com, clinton.slabbert@windriver•com,
kuznet@ms2•inr.ac.ru, jmorris@namei•org, kaber@trash•net,
netdev@vger•kernel.org
Cc: hideaki.yoshifuji@miraclelinux•com,
"YOSHIFUJI Hideaki (USAGI Project)" <yoshfuji@linux-ipv6•org>
Subject: Re: [PATCH V2 0/1] neighbour: Support broadcast ARP in neighbor PROPE state
Date: Wed, 18 Mar 2015 19:34:12 +0900 [thread overview]
Message-ID: <550954A4.2070900@miraclelinux.com> (raw)
In-Reply-To: <55093C76.3030208@ericsson.com>
Hi,
Ulf Samuelsson wrote:
>
> On 03/12/2015 09:42 AM, YOSHIFUJI Hideaki wrote:
>> Hello.
>>
>> yzhu1 wrote:
>>> The state machine is in the attachment.
>>>
>>> Best Regards!
>>> Zhu Yanjun
>>> On 03/12/2015 02:58 PM, Zhu Yanjun wrote:
>>>> V2:
>>>> set ARP_PROBE_BCAST default N.
>>>>
>>>> V1:
>>>> Have a problem with an HP router at a certain location, which
>>>> is configured to only answer to broadcast ARP requests.
>>>> That cannot be changed.
>>>>
>>>> The first ARP request the kernel sends out, is a broadcast request,
>>>> which is fine, but after the reply, the kernel sends unicast requests,
>>>> which will not get any replies.
>>>>
>>>> The ARP entry will after some time enter STALE state,
>>>> and if nothing is done it will time out, and be removed.
>>>> This process takes to long, and I have been told that it is
>>>> difficult to makes changes that will eventually remove it.
>>>>
>>>> Have tried to change the state from STALE to INCOMPLETE, which failed,
>>>> and then tried to change the state to PROBE which also failed.
>>>>
>>>> The stack is only sending out unicasts, and never broadcast.
>>>> Is there any way to get the stack to send out a broadcast ARP
>>>> without having to wait for the entry to be removed?
>>
>> Neighbour subsystem will send multicast probes after unicast
>> probes in NUD_PROBE state if mcast_solicit is more than
>> ucast_solicit. Try setting net.ipv4.neigh.*.ucast_solicit to
>> the value less than net.ipv4.neigh.*.mcast_solicit, please?
>> e.g.
>>
>> net.ipv4.neigh.eth0.mcast_solicit = 3
>> net.ipv4.neigh.eth0.ucast_solicit = 1
>>
>> --yoshfuji
>>
> I dont see how, and I would like to focus on code discussion.
>
> Below is simplified pseudo code of the timer handler
> after you have reached REACHABLE the first time.
>
> "mcast_solicit" is not used at all.
>
> It is only used when in INCOMPLETE state as far as I can tell.
OK, I found I made this change in 2003:
From d12fd76789e80ae337408834f45dae7cba23fc55 Mon Sep 17 00:00:00 2001
From: Hideaki Yoshifuji <yoshfuji@linux-ipv6•org>
Date: Sun, 6 Jul 2003 23:32:45 +1000
Subject: [PATCH] [NET] Send only unicast NSs in PROBE state.
---
net/core/neighbour.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index c640ad5..001fdb4 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -608,7 +608,9 @@ next_elt:
static __inline__ int neigh_max_probes(struct neighbour *n)
{
struct neigh_parms *p = n->parms;
- return p->ucast_probes + p->app_probes + p->mcast_probes;
+ return (n->nud_state & NUD_PROBE ?
+ p->ucast_probes :
+ p->ucast_probes + p->app_probes + p->mcast_probes);
}
As I recall, I was hesitating adding new sysctl knob, but now I am
okay to have knob to enable mcast probes in PROBE state as well.
(By default, it should NOT send multicast probe (expecially for IPv6)
in PROBE state.)
How about these?
- introduce probe_mcast_probes knob, default to 0.
- Change neigh_max_probes() to reflect that.
Then, arp_colisit() and ndict_solicit() should send multicast probes
in PROBE state as well, if probe_mcast_probes is set to positive
value.
Will this work for you?
Regards,
--yoshfuji
>
>
> Best Regards,
> Ulf Samuelsson
>
>
>
>>
>>>>
>>>> I think the recommended behaviour in IPv6 is to send out 3 unicasts
>>>> and if all fails, to send out broadcasts.
>>>>
>>>> Zhu Yanjun (1):
>>>> neighbour: Support broadcast ARP in neighbor PROPE state
>>>>
>>>> include/net/neighbour.h | 7 ++++++
>>>> include/uapi/linux/neighbour.h | 6 +++++
>>>> include/uapi/linux/sysctl.h | 3 +++
>>>> kernel/sysctl_binary.c | 3 +++
>>>> net/core/neighbour.c | 44 +++++++++++++++++++++++++++++---
>>>> net/ipv4/Kconfig | 57 ++++++++++++++++++++++++++++++++++++++++++
>>>> net/ipv4/arp.c | 7 ++++--
>>>> 7 files changed, 121 insertions(+), 6 deletions(-)
>>>>
>>>
>>
>
--
吉藤英明 <hideaki.yoshifuji@miraclelinux•com>
ミラクル・リナックス株式会社 技術本部 サポート部
next prev parent reply other threads:[~2015-03-18 10:34 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-12 6:58 [PATCH V2 0/1] neighbour: Support broadcast ARP in neighbor PROPE state Zhu Yanjun
2015-03-12 6:58 ` [PATCH V2 1/1] " Zhu Yanjun
2015-03-12 10:05 ` YOSHIFUJI Hideaki/吉藤英明
2015-03-12 7:10 ` [PATCH V2 0/1] " yzhu1
2015-03-12 8:42 ` YOSHIFUJI Hideaki
2015-03-12 8:59 ` Ulf samuelsson
2015-03-12 9:28 ` YOSHIFUJI Hideaki/吉藤英明
2015-03-12 9:45 ` Ulf samuelsson
2015-03-12 10:16 ` YOSHIFUJI Hideaki
2015-03-18 8:51 ` Ulf Samuelsson
2015-03-18 10:34 ` YOSHIFUJI Hideaki/吉藤英明 [this message]
2015-03-18 12:15 ` Ulf Samuelsson
2015-03-18 13:22 ` YOSHIFUJI Hideaki/吉藤英明
2015-03-18 15:12 ` Ulf Samuelsson
2015-03-19 2:42 ` yzhu1
2015-03-19 2:14 ` yzhu1
2015-03-19 2:24 ` yzhu1
2015-03-12 19:22 ` David Miller
2015-03-16 12:39 ` Ulf Samuelsson
2015-03-19 5:52 ` yzhu1
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=550954A4.2070900@miraclelinux.com \
--to=hideaki.yoshifuji@miraclelinux$(echo .)com \
--cc=Yanjun.Zhu@windriver$(echo .)com \
--cc=alexandre.dietsch@windriver$(echo .)com \
--cc=brian.haley@hp$(echo .)com \
--cc=clinton.slabbert@windriver$(echo .)com \
--cc=davem@davemloft$(echo .)net \
--cc=jmorris@namei$(echo .)org \
--cc=kaber@trash$(echo .)net \
--cc=kuznet@ms2$(echo .)inr.ac.ru \
--cc=netdev@vger$(echo .)kernel.org \
--cc=ulf.samuelsson@ericsson$(echo .)com \
--cc=yoshfuji@linux-ipv6$(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