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Message-Id: <B73D6B9F-3BD0-4563-9921-AC328C686276@sfc.wide.ad.jp>
Date: Mon, 25 Apr 2011 11:29:56 +0900
From: Michio Honda <micchie@....wide.ad.jp>
To: Wei Yongjun <yjwei@...fujitsu.com>
Cc: netdev@...r.kernel.org, lksctp-developers@...ts.sourceforge.net
Subject: Re: [PATCH net-next-2.6 v4 4/5] sctp: Add ASCONF operation on the single-homed host
Yes, I think the association cannot be kept, if the single-homed ASCONF receiver moves to the new network before sending ASCONF-ACK.
Am I missing?
Thanks,
- Michio
On Apr 25, 2011, at 11:02 , Wei Yongjun wrote:
>
>> Hi,
>>
>> Such operation would not be supported by specification, in Sec.5.3 in RFC 5061:
>> F1) When adding an IP address to an association, the IP address is
>> NOT considered fully added to the association until the ASCONF-
>> ACK arrives. This means that until such time as the ASCONF
>> containing the add is acknowledged, the sender MUST NOT use the
>> new IP address as a source for ANY SCTP packet except on
>> carrying an ASCONF Chunk.
>>
>> I think this means we cannot send ASCONF-ACK from the new address even if it bundles ASCONF...
>
> If so, both side do not have valid address to send the such
> ASCONF-ACK, and can not recv ASCONF-ACK.
>
>> - Michio
>>
>> On Apr 25, 2011, at 9:57 , Wei Yongjun wrote:
>>
>>>> On Apr 22, 2011, at 13:10 , Wei Yongjun wrote:
>>>>
>>>>>> Since the sender MUST NOT use the new IP address as a source for ANY SCTP
>>>>>> packet except on carrying an ASCONF Chunk. And ASCONF chunk can be bundled.
>>>>>> How about this change. If so, you do not need change to sctp_outq_tail();
>>>>>>
>>>>>> diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
>>>>>> index 1c88c89..bd6cc9c 100644
>>>>>> --- a/net/sctp/outqueue.c
>>>>>> +++ b/net/sctp/outqueue.c
>>>>>> @@ -754,6 +754,13 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
>>>>>> */
>>>>>>
>>>>>> list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
>>>>>> + /* RFC 5061, 5.3
>>>>>> + * F1) This ...
>>>>>> + */
>>>>>> + if (q->asoc->src_out_of_asoc_ok &&
>>>>>> + chunk->chunk_hdr->type != SCTP_CID_ASCONF)
>>>>> SCTP_CID_ASCONF_ACK should be also allowed, the peer may
>>>>> send ASCONF to do the same thing at the same time.
>>>> Sorry for my bad understanding,
>>>> Do you mean the situation: "the peer (ASCONF receiver) may send ASCONF-ACK to the unconfirmed destination"?
>>>> Or do you mean following situation?
>>>> 1. the pear sends ADD/DEL ASCONF to me,
>>>> 2. I receive it,
>>>> 3. I migrate to the other network and get new address,
>>>> 4. I send ASCONF-ACK to the peer from the new address
>>> Yes, If both side send ADD/DEL ASCONF to del the last one
>>> address at the same time like this:
>>>
>>> ASCONF ----- ------ASCONF
>>> (ADD/DEL) \ / (ADD/DEL)
>>> \/
>>> /\
>>> <----/ \----->
>>> ASCONF-ACK---\ /------ASCONF-ACK
>>> \/
>>> /\
>>> <----/ \----->
>>>
>>> But I do not test for it. Not sure we need to do this, can you
>>> check this before commit your new patchset?
>>>
>>>
>>>>>> + continue;
>>>>>> +
>>>>>> list_del_init(&chunk->list);
>>>>>>
>>>>>> /* Pick the right transport to use. */
>>>>>> @@ -881,6 +888,9 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
>>>>>> }
>>>>>> }
>>>>>>
>>>>>> + if (q->asoc->src_out_of_asoc_ok)
>>>>>> + goto sctp_flush_out;
>>>>>> +
>>>>>> /* Is it OK to send data chunks? */
>>>>>> switch (asoc->state) {
>>>>>> case SCTP_STATE_COOKIE_ECHOED:
>>>>>>
>>>>>>
>>>>>>
>>>>> --
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