All of lore.kernel.org
 help / color / mirror / Atom feed
From: Sun Paul <paulrbk@gmail.com>
To: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Daniel Borkmann <dborkman@redhat.com>,
	Michael Tuexen <tuexen@fh-muenster.de>,
	Vlad Yasevich <vyasevich@gmail.com>,
	linux-sctp@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: Question on SCTP ABORT chunk is generated when the association_max_retrans is reached
Date: Mon, 26 Jan 2015 21:17:02 +0800	[thread overview]
Message-ID: <CAFXGftJNZ48Qe4DLgf5TPBvNCnUH8wxon9+b3_i_GWVYqnphhg@mail.gmail.com> (raw)
In-Reply-To: <54C62912.3040401@gmail.com>

When an ABORT is sent to side-A, side-A INIT a new connection again.

On Mon, Jan 26, 2015 at 7:46 PM, Marcelo Ricardo Leitner
<marcelo.leitner@gmail.com> wrote:
> Hi,
>
> On 25-01-2015 23:27, Sun Paul wrote:
>>
>> Hi
>>
>> sorry for the late reply. I am a bit confused. when side-A sends a
>> request to side-B, and side-B return the response, but side-A keep
>> re-transmit the same request to side-B, why side-B needed to send a
>> ABORT to side-A?
>
>
> That happens on data transfers. When A pushes data to B, A has to retry it
> until B finally acknowledges it and A receive this signal. If the ack from B
> gets dropped, A has no way to know if a) the ack was lost or b) its initial
> message never actually made it to A, thus it retransmits. If it reaches a
> limit, it gives up..
>
>> If it is used in order to reestablish the connection, shoudn't it
>> should be side-A to send ABORT instead?
>
>
> Meant to reestablish it? Not really.. just to keep both sides in sync, as A
> has given up by then.
>
>   Marcelo
>
>> - PS
>>
>> On Sat, Jan 24, 2015 at 3:05 AM, Daniel Borkmann <dborkman@redhat.com>
>> wrote:
>>>
>>> On 01/23/2015 07:36 PM, Michael Tuexen wrote:
>>> ...
>>>>
>>>>
>>>> Yepp. It might not reach the peer or it might. If it does it helps
>>>> to keep the states in sync. If it doesn't it sometimes helps in
>>>> analysing tracefiles. In BSD, we also send it. It is not required,
>>>> doesn't harm and is useful in some cases...
>>>
>>>
>>>
>>> Ok, as the TCB is destroyed in any case, should be fine then.
>>>
>>> Thanks,
>>> Daniel
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe netdev" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>

WARNING: multiple messages have this Message-ID (diff)
From: Sun Paul <paulrbk@gmail.com>
To: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Daniel Borkmann <dborkman@redhat.com>,
	Michael Tuexen <tuexen@fh-muenster.de>,
	Vlad Yasevich <vyasevich@gmail.com>,
	linux-sctp@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: Question on SCTP ABORT chunk is generated when the association_max_retrans is reached
Date: Mon, 26 Jan 2015 13:17:02 +0000	[thread overview]
Message-ID: <CAFXGftJNZ48Qe4DLgf5TPBvNCnUH8wxon9+b3_i_GWVYqnphhg@mail.gmail.com> (raw)
In-Reply-To: <54C62912.3040401@gmail.com>

When an ABORT is sent to side-A, side-A INIT a new connection again.

On Mon, Jan 26, 2015 at 7:46 PM, Marcelo Ricardo Leitner
<marcelo.leitner@gmail.com> wrote:
> Hi,
>
> On 25-01-2015 23:27, Sun Paul wrote:
>>
>> Hi
>>
>> sorry for the late reply. I am a bit confused. when side-A sends a
>> request to side-B, and side-B return the response, but side-A keep
>> re-transmit the same request to side-B, why side-B needed to send a
>> ABORT to side-A?
>
>
> That happens on data transfers. When A pushes data to B, A has to retry it
> until B finally acknowledges it and A receive this signal. If the ack from B
> gets dropped, A has no way to know if a) the ack was lost or b) its initial
> message never actually made it to A, thus it retransmits. If it reaches a
> limit, it gives up..
>
>> If it is used in order to reestablish the connection, shoudn't it
>> should be side-A to send ABORT instead?
>
>
> Meant to reestablish it? Not really.. just to keep both sides in sync, as A
> has given up by then.
>
>   Marcelo
>
>> - PS
>>
>> On Sat, Jan 24, 2015 at 3:05 AM, Daniel Borkmann <dborkman@redhat.com>
>> wrote:
>>>
>>> On 01/23/2015 07:36 PM, Michael Tuexen wrote:
>>> ...
>>>>
>>>>
>>>> Yepp. It might not reach the peer or it might. If it does it helps
>>>> to keep the states in sync. If it doesn't it sometimes helps in
>>>> analysing tracefiles. In BSD, we also send it. It is not required,
>>>> doesn't harm and is useful in some cases...
>>>
>>>
>>>
>>> Ok, as the TCB is destroyed in any case, should be fine then.
>>>
>>> Thanks,
>>> Daniel
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe netdev" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>

  reply	other threads:[~2015-01-26 13:17 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-23 10:09 Question on SCTP ABORT chunk is generated when the association_max_retrans is reached Sun Paul
2015-01-23 10:25 ` Fwd: " Sun Paul
2015-01-23 10:25   ` Sun Paul
2015-01-23 11:50   ` Daniel Borkmann
2015-01-23 11:50     ` Daniel Borkmann
2015-01-23 16:05     ` Vlad Yasevich
2015-01-23 16:05       ` Vlad Yasevich
2015-01-23 17:10       ` Daniel Borkmann
2015-01-23 17:10         ` Daniel Borkmann
2015-01-23 18:30         ` Vlad Yasevich
2015-01-23 18:30           ` Vlad Yasevich
2015-01-23 18:36           ` Michael Tuexen
2015-01-23 18:36             ` Michael Tuexen
2015-01-26 13:47           ` Fwd: " Neil Horman
2015-01-26 13:47             ` Neil Horman
2015-01-23 18:36         ` Michael Tuexen
2015-01-23 18:36           ` Michael Tuexen
2015-01-23 19:05           ` Daniel Borkmann
2015-01-23 19:05             ` Daniel Borkmann
2015-01-26  1:27             ` Sun Paul
2015-01-26  1:27               ` Sun Paul
2015-01-26 11:46               ` Marcelo Ricardo Leitner
2015-01-26 11:46                 ` Marcelo Ricardo Leitner
2015-01-26 13:17                 ` Sun Paul [this message]
2015-01-26 13:17                   ` Sun Paul
2015-01-26 13:30                   ` Daniel Borkmann
2015-01-26 13:30                     ` Daniel Borkmann
2015-01-23 16:08   ` Fwd: " Vlad Yasevich
2015-01-23 16:08     ` Vlad Yasevich

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=CAFXGftJNZ48Qe4DLgf5TPBvNCnUH8wxon9+b3_i_GWVYqnphhg@mail.gmail.com \
    --to=paulrbk@gmail.com \
    --cc=dborkman@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-sctp@vger.kernel.org \
    --cc=marcelo.leitner@gmail.com \
    --cc=netdev@vger.kernel.org \
    --cc=tuexen@fh-muenster.de \
    --cc=vyasevich@gmail.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.