Thanks - I'm inclined to leave that one, I'm not sure why (possibly
because of the division rather than using the value directly) but that
one feels better to me as-is.
On 2018/05/09 13:45, BRAND Arnaud wrote:
> I do agree with you.
> I based my patch on the code on the ifHighSpeed case block at line 1291 in
> the same file.
> You might want to make it more explicit too.
>
> -----Message d'origine-----
> De : Stuart Henderson <s...@spacehopper.org>
> Envoyé : mercredi 9 mai 2018 15:41
> À : BRAND Arnaud <arnaud.br...@md6.fr>
> Cc : bugs@openbsd.org
> Objet : Re: snmpd ifSpeed reporting seems wrong for speeds over 4G (ex: 10G)
>
> On 2018/05/09 12:48, BRAND Arnaud wrote:
> > Hi,
> >
> > I would like to report was looks like a bug in snmpd.
> >
> > When walking on the ifTable my client crashes when walking over 10G
> > interfaces.
> > Tcpdump shows that ifSpeed (1.3.6.1.2.1.2.2.1.5) is sending the value
> > 10000000000 (10Gbps).
> > But ifSpeed is of type GAUGE and maxes out at 2^32-1 (4Gbps-1).
> >
> > My MIB browser states :
> > "An estimate of the interface's current bandwidth in bits per second.
> > For interfaces which do not vary in bandwidth or for those where no
> > accurate estimation can be made, this object should contain the
> > nominal bandwidth. If the bandwidth of the interface is greater than
> > the maximum value reportable by this object then this object should
> > report its maximum value (4,294,967,295) and ifHighSpeed must be used
> > to report the interace's speed. For a sub-layer which has no concept
> > of bandwidth, this object should be zero."
> >
> > So I guess the case block at line 1111 in /usr.sbin/snmpd/mib.c should read
> > :
> > case 5:
> > i = kif->if_baudrate >= 4294967295 ?
> > 4294967295 :
> > kif->if_baudrate ;
> > ber = ber_add_integer(ber, i);
> > ber_set_header(ber, BER_CLASS_APPLICATION,
> > SNMP_T_GAUGE32);
> > break;
> > instead of
> > case 5:
> > ber = ber_add_integer(ber, kif->if_baudrate);
> > ber_set_header(ber, BER_CLASS_APPLICATION,
> > SNMP_T_GAUGE32);
> > break;
> >
> > Is my assumption correct or have I missed something ?
> >
> > I'm gonna give it a try while a fix perhaps makes its way in the next
> > release or patches.
> >
> > Have a nice day and thanks for your nice work in OpenBSD !
> >
> > Best regards
> > Arnaud
>
> I think that's the right thing to do, but an if() and using a macro instead
> of writing 4294967295 out in full is easier on the eye.
> Any OKs for this?
>
>
> Index: mib.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/snmpd/mib.c,v retrieving revision 1.85 diff -u -p
> -r1.85 mib.c
> --- mib.c 18 Dec 2017 05:51:53 -0000 1.85
> +++ mib.c 9 May 2018 13:38:50 -0000
> @@ -1109,7 +1109,11 @@ mib_iftable(struct oid *oid, struct ber_
> ber = ber_add_integer(ber, kif->if_mtu);
> break;
> case 5:
> - ber = ber_add_integer(ber, kif->if_baudrate);
> + if (kif->if_baudrate > UINT32_MAX) {
> + /* speed should be obtained from ifHighSpeed instead */
> + ber = ber_add_integer(ber, UINT32_MAX);
> + } else
> + ber = ber_add_integer(ber, kif->if_baudrate);
> ber_set_header(ber, BER_CLASS_APPLICATION, SNMP_T_GAUGE32);
> break;
> case 6:
>
>
