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Re: RE: RE: RE: [Freeipmi-devel] Using libfreeipmi interface
From: |
Albert Chu |
Subject: |
Re: RE: RE: RE: [Freeipmi-devel] Using libfreeipmi interface |
Date: |
Fri, 29 Oct 2004 09:04:51 -0700 |
Hi Andrew,
> Where did the 0x3f arbitrary sequence limit come from anyway? I
> couldn't find any reference to sequence number limits in the IPMI spec
> or platform specs.
The 0x3f comes from the fact the requester sequence number is 6 bits
long. You can see this in section 7.3, figure 7-1 of the IPMI 1.5 spec.
(That section is pointed to by section 12.4, which discusses IPMI over
Lan).
I get the feeling you are passing in session sequence numbers, which are
32 bits, in place of the requester sequence numbers, which are 6 bits
long. The session sequence number is passed to the fill_hdr_session()
function when building a packet and the requester sequence number is
passed to fill_lan_msg_hdr().
Al
--
Albert Chu
address@hidden
Lawrence Livermore National Laboratory
----- Original Message -----
From: "Cress, Andrew R" <address@hidden>
Date: Friday, October 29, 2004 7:44 am
Subject: RE: RE: RE: [Freeipmi-devel] Using libfreeipmi interface
>
> re: IPMI_LAN_SEQ_NUM_MAX (=0x3F)
>
> As a use case, to understand the problem this causes, one of my
> applications 'showsel' allows reading the IPMI SEL. This can be quite
> long on Intel platforms (e.g. 4032 record capacity on one test system
> here). On one test system, with 257 SEL records, the sequence number
> increments to 267 (0x10B), and wrapping the sequence number during
> thissession causes the IPMI chipset to ignore the command with a
> duplicate/lower sequence number (and the app/lib would hang). This
> would also affect the fish/sel script/app similarly. The sequence
> number is 32 bits, and incrementing up through that capacity is
> allowed.My Tiger (ia64) system isn't up right now, but as I recall,
> it behaves
> the same way.
>
> Where did the 0x3f arbitrary sequence limit come from anyway? I
> couldn't find any reference to sequence number limits in the IPMI spec
> or platform specs.
>
> So, my position is that it is not just inappropriate to check sequence
> number bounds at 0x3f, but invalid for IPMI 1.5 platforms with LAN
> support (a bug).
>
> Andy
>
> -----Original Message-----
> From: Albert Chu [mailto:address@hidden
> Sent: Thursday, October 28, 2004 8:04 PM
> To: Cress, Andrew R
> Cc: address@hidden
> Subject: Re: RE: RE: [Freeipmi-devel] Using libfreeipmi interface
>
>
> > I also found a problem with the IPMI_LAN_SEQ_NUM_MAX (=0x3F).
> > There isn't any precedent in IPMI 1.5 for this, and limiting the
> 32-
> > bitsequence number to 6 bits causes some problems, since the BMC
> > LAN won't handle wrapping the sequence number back to 0 or 1
> after 63
> > (0x3f).
>
> I'm not quite convinced this is a problem. The bounds check makes the
> user knowledgeable to the fact that arbitrary sequence numbers aren't
> allowed. I spoke to a few other developers I work with, and they feel
> that the bounds checking is more appropriate. Ab, Ian, Bala, what are
> your thoughts??
>
>
- RE: [Freeipmi-devel] Using libfreeipmi interface, (continued)
- RE: [Freeipmi-devel] Using libfreeipmi interface, Cress, Andrew R, 2004/10/27
- Re: RE: [Freeipmi-devel] Using libfreeipmi interface, Albert Chu, 2004/10/28
- RE: RE: [Freeipmi-devel] Using libfreeipmi interface, Cress, Andrew R, 2004/10/28
- Re: RE: RE: [Freeipmi-devel] Using libfreeipmi interface, Albert Chu, 2004/10/28
- Re: [Freeipmi-devel] Using libfreeipmi interface, Albert Chu, 2004/10/28
- RE: RE: RE: [Freeipmi-devel] Using libfreeipmi interface, Cress, Andrew R, 2004/10/29
- RE: [Freeipmi-devel] Using libfreeipmi interface, Cress, Andrew R, 2004/10/29
- RE: [Freeipmi-devel] Using libfreeipmi interface, Cress, Andrew R, 2004/10/29
- Re: RE: RE: RE: [Freeipmi-devel] Using libfreeipmi interface,
Albert Chu <=