Re: [Tsvwg] SCTP stream EOF

[Florian Niederbacher <[e-mail]>]

Randy Stewart schrieb:
> Florian:
>
> What do you mean by an EOF?
Same as EOF for files. That blocking recv and recvmsg can be stopped.
>
> For messages there is a SCTP_EOR to tell you a "message" as ended.
Yes, but only for message you pick up from recv- buffer if I interpret 
it right from socket_api-spec.
E.g. transfer Hello in to messages hel - lo. After 'lo' I get an EOF.
SCTP_EOR does only indicate that the message can be read in full in one 
read/recv, or not? Because i get always SCTP_EOR in my app, only if the 
messagesize is bigger then the buffer for recv\recv_msg.
>
>
> If you were using stream reset, and the peer decides to "reset" a stream
> and then use the stream for some other purpose (this is what I think you
> are stating).... then the user would get a STREAM_RESET event for that
> stream.
>
> I don't see the difference (other than name) in stream-x has been reset
> vs stream X receives a EOF. Note that an app MAY choose to use a RESET
> as a EOF.. but it can also mean something different to an app.. I am done
> sending this type of message, I will now send other types of messages.
> Which is different than an EOF....
Yes I agree. I didn't know that STREAM_RESET is handled as event. This 
would definitely solve my case. But is this already implemented in LKSCTP?

>
> Note also that the socket-api section is still missing (if I remember 
> right) from
> the stream-reconfig draft... I do need to add this. But I really think
> the Stream-Reset serves the purpose you are looking for.
>
> R
> On Sep 17, 2008, at 9:49 AM, Florian Niederbacher wrote:
>
>> Hi,
>> I would ask what are you thinking about a definition for an EOF on 
>> streams in SCTP. My problem is that I would need a signaling method 
>> to report an EOF without closing the whole SCTP association. If I am 
>> right, socket connections get only an EOF if the connection will be 
>> closed (no sending of EOF on socktes in another way is possible). In 
>> draft-stewart-tsvwg-sctpstrrst-00 the possibility the reset of 
>> streams is discussed. This would also be a solution if you can check 
>> the numbering sequence in User Space.
>> A proposal would be to generate an SCTP_EVENT e.g. SCTP_STREAM_EOF to 
>> signal EOF on streams. In this way you can stop receiving and also 
>> reuse the stream or at least continue in multi-streamed network 
>> applications, if you use different threads or processes for the 
>> receiving procedure on streams. Maybe an other possibility exists to 
>> signal an EOF on SCTP streams, but at the moment I can't find any 
>> solution to deal with this problem. What are your proposals and 
>> comments?
>>
>> Best regards
>> Florian Niederbacher
>
> -----
> Randall Stewart
> [e-mail]
>
>
>
>
>

- Regards Florian