Re: [PATCH] sctp: Make "Invalid Stream Identifier" ERROR follows SACKwhen bundling

From: Xufeng Zhang
Date: Wed Jul 25 2012 - 05:22:15 EST


On 7/25/12, Xufeng Zhang <xufengzhang.main@xxxxxxxxx> wrote:
> On 7/25/12, Vlad Yasevich <vyasevich@xxxxxxxxx> wrote:
>>
>> Actually not true. AUTH can be before SACK. So can any addip chunks
>> that
>> aid in locating an association.
>>
>> Now AUTH isn't a big issue since its autogenerated to the packet but
>> ADDIP
>> is since it could be queued up for retransmission.
>>
>> There could be other extensions as well. It really needs to be done
>> either
>> through side effects or making error chunks go at the end of other
>> control
>> chunks. Need to audit the spec to see if that's ok.
> You are right, I just found SHUTDOWN chunks are also before SACK based on
> your commit "[SCTP]: Fix SACK sequence during shutdown".
> Maybe the only solution is to do some work on side effects just as you
> said.
> Thanks for your explanation!

And after take a moment to look into the relative codes, I think we
can implement it
by below way:
1). Add a flag(isi_err_needed) in the embedded struct peer of struct
struct sctp_association
just like sack_needed flag.
2). When "invalid stream identifier" ERROR happens in sctp_eat_data()
function, we just
set isi_err_needed flag and don't create ERROR chunk and also don't
insert SCTP_CMD_REPLY command.
3). In sctp_gen_sack() function, we create ERROR chunk and also insert
SCTP_CMD_REPLY command if isi_err_needed flag is set.

Is this way proper?


Thanks,
Xufeng Zhang
>
>
>
> Thanks,
> Xufeng Zhang
>>
>> -vlad
>>>
>>>Thanks,
>>>Xufeng Zhang
>>>>
>>>> -vlad
>>
>>
>> --
>> Sent from my Android phone with SkitMail. Please excuse my brevity.
>>
>
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