Subject: Error codes not defined in RFC 2960

From: [email-masked] (Antonio Alonso Alarcon ECE/TL/NA TU-148 Tlf.3085)
Date: Fri, 16 Mar 2001 12:36:49 +0100 (MET)

Hi !

   I have been reading several SCTP related drafts (and, of course,
RFC 2960) and I could not find error codes for these two cases:

1)
   RFC 2960 specifies (section 3.1, page 17):

      -  A packet containing an INIT chunk MUST have a zero Verification
         Tag.

   If an SCTP layer receives an INIT chunk and the VT in the SCTP header is
different from 0, should it send an ERROR or an ABORT chunk ?. Which (maybe new)
error code must be sent in the ABORT/ERROR chunk ?. If a new error code is
going to be defined for it, which will be the coding value for it ?

2)
  In 2nd bake-off was discovered a security "hole" in the SCTP re-start
procedure (as described in the bake-off draft). When a "duplicate" INIT
is received including IPv4/IPv6 TLV parameters with NEW ip addresses
(i.e addresses not stored in the existing TCB structure) and ERROR chunk
must be sent with a new error code. Is there any documente where this
new error code has been defined ?. If answer is "no", is there anybody
going to define it in a new draft extending the RFC 2960 ?

Regards / Antonio

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From: Qiaobing Xie <[email-masked]>
Date: Fri, 16 Mar 2001 11:23:59 -0600

Antonio,

I don't think we have error codes for the two cases you mentioned.

In general, before allocating an error code, we should first ask
ourselves whether an error really needs to be reported back to the peer,
i.e. what is the benefit of reporting it to the peer?

This is because there are so many different ways the protocol can be
violated and we cannot assign an error code and report every one of
them.

Unnecessary error reporting can also cause security problems, such as
being used as a flooding attack reflector.

-Qiaobing

"Antonio Alonso Alarcon ECE/TL/NA TU-148 Tlf.3085" wrote:
> You are currently subscribed to sigtran as: [email-masked]

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From: [email-masked]
Date: Sat, 17 Mar 2001 15:22:00 +0200

See below Antonio...

> > going to be defined for it, which will be the coding value for it ?

	If you go to the first paragraph in page 26, you will see that you
must send an ABORT. In my case I include the 'Invalid Mandatory Parameter'
error code...

> > going to define it in a new draft extending the RFC 2960 ?

	Go to section 2.4 of

http://search.ietf.org/internet-drafts/draft-stewart-ong-sctpbakeoff-sigtran
-01.txt

	I think that this will be managed in RFC2960 Bis...

> > Regards / Antonio

	I hope it was of some help...

	BR Iván Arias Rodríguez	

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From: "Brian F. G. Bidulock" <[email-masked]>
Date: Sat, 17 Mar 2001 15:30:14 -0600

Ivan.Arias-Rodriguez,

On Sat, 17 Mar 2001, [email-masked] wrote:

> > >    I have been reading several SCTP related drafts (and,
> > > of course, RFC 2960) and I could not find error codes
> > > for these two cases:
> > > 
> > > 1)
> > >       -  A packet containing an INIT chunk MUST have a zero 
> > >          Verification Tag.
> > > 
> > >    If an SCTP layer receives an INIT chunk and the VT in
> > >    the SCTP header is different from 0, should it send
> > >    an ERROR or an ABORT chunk ?. Which (maybe new) error
> > >    code must be sent in the ABORT/ERROR chunk ?. If a
> > >    new error code is going to be defined for it, which
> > >    will be the coding value for it ?
> 
> 	If you go to the first paragraph in page 26, you will
> see that you must send an ABORT. In my case I include the
> 'Invalid Mandatory Parameter' error code...
> 

The first paragraph on page 26 deals is a 0 in an Initiate Tag
not non-zero VT in an INIT chunk.  Non-zero VT in an INIT
chunk is dealt with in section 8.4.  And if you follow down
the logic of 8.4 you drop through the list and wind up at 8.4(8)
and thus treat it as a regular OOTB packet.

-- 
Brian F. G. Bidulock    ¦ The reasonable man adapts himself to the ¦
[email-masked]    ¦ world; the unreasonable one persists in  ¦
http://www.openss7.org/ ¦ trying  to adapt the  world  to himself. ¦
                        ¦ Therefore  all  progress  depends on the ¦
                        ¦ unreasonable man. -- George Bernard Shaw ¦

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