On Thu, Mar 9, 2017 at 10:02 PM, Joel Knight <[email protected]> wrote:
> Hi.
>
> snmpd(8) uses unsigned ints internally to represent the size and used
> space of a file system. The HOST-RESOURCES-MIB defines the valid
> values for those OIDs as 0..2147483647. With sufficiently large file
> systems, this can cause negative numbers to be returned for the size
> and used space OIDs.
>
> .1.3.6.1.2.1.25.2.3.1.5.36=-1573167768
Hi. Just wanted to bump this again and see if anyone that cares about
snmp could take a look? Looking for oks and someone who wouldn't mind
committing it.
> At sthen's suggestion, do what net-snmp does and fiddle with the
> values to prevent wrapping. Yes this mucks with the actual values of
> size, used space, and block size, but it allows snmpd to convey the
> proper size and used space of the file system which is what most
> everybody is really interested in.
>
> In case gmail hoses this diff, it's also here:
> https://www.packetmischief.ca/files/patches/snmpd.hrstorage2.diff
Index: usr.sbin/snmpd/mib.c
===================================================================
RCS file: /data/cvs-mirror/OpenBSD/src/usr.sbin/snmpd/mib.c,v
retrieving revision 1.80
diff -p -u -r1.80 mib.c
--- usr.sbin/snmpd/mib.c 17 Nov 2015 12:30:23 -0000 1.80
+++ usr.sbin/snmpd/mib.c 19 Feb 2017 20:01:46 -0000
@@ -643,6 +643,14 @@ mib_hrstorage(struct oid *oid, struct be
units = mnt->f_bsize;
size = mnt->f_blocks;
used = mnt->f_blocks - mnt->f_bfree;
+
+ /* for large filesystems, do not overflow hrStorageSize */
+ while (size > INT32_MAX) {
+ size = size >> 1;
+ units = units << 1;
+ used = used >> 1;
+ }
+
sop = &so[3];
break;
}
