Philip Guenther <guent...@gmail.com> writes:
> On Sun, Jul 14, 2013 at 12:54 AM, Rafael Neves <rafaelne...@gmail.com> wrote:
>> The patch below fixes a bug on sysctl(8) introduced by revision 1.191
>> of sysctl.c. After rev1.191, `sysctl vfs' mangles information about
>> filesystems (mounted instances of ffs are attributed to nfs, of nfs
>> are atrributed to mfs, and so on). As a consequence, `sysctl
>> vfs.mounts.nfs' reports 0 mounted instances on a diskless(8) setup,
>> thus /etc/rc script (lines 335 to 342) doesn't add pf rules that allow
>> NFS, and system hangs when it enables pf.
>
> First off: thank you for (a) noticing this, and (b) tracking down the
> mismatch.
>
> ...
>> --- sysctl.c 9 Jun 2013 12:54:38 -0000 1.192
>> +++ sysctl.c 14 Jul 2013 07:09:28 -0000
>> @@ -1175,8 +1175,8 @@ vfsinit(void)
>>
>> vfsname[0].ctl_name = "mounts";
>> vfsname[0].ctl_type = CTLTYPE_NODE;
>> - vfsvars[0].list = vfsname + 1;
>> - vfsvars[0].size = maxtypenum - 1;
>> + vfsvars[0].list = vfsname;
>> + vfsvars[0].size = maxtypenum;
>
> Soooooo close...
>
> While this fixes the observed problem, it's not 100% correct. The
> glitch is that it fails a negative test: the command
> sysctl vfs.mounts.mounts
> should fail with the error
> sysctl: third level name mounts in vfs.mounts.mounts is invalid
>
> but with your patch it silently succeeds. The vfsname list is offset
> by one in vfsvars[0].list to prevent that, so the fix that avoids the
> unwanted match against vfsname[0] is to keep the offset, but undo it
> in the lookup:
>
> --- sysctl.c 9 Jun 2013 12:54:38 -0000 1.192
> +++ sysctl.c 15 Jul 2013 03:43:27 -0000
> @@ -1200,7 +1200,7 @@ sysctl_vfsgen(char *string, char **bufpp
>
> mib[1] = VFS_GENERIC;
> mib[2] = VFS_CONF;
> - mib[3] = indx;
> + mib[3] = indx + 1;
> size = sizeof vfc;
> if (sysctl(mib, 4, &vfc, &size, (void *)0, (size_t)0) < 0) {
> if (errno != EOPNOTSUPP)
>
>
> That makes sense?
It does make sense to me. ok jca@
--
Jérémie Courrèges-Anglas
PGP Key fingerprint: 61DB D9A0 00A4 67CF 2A90 8961 6191 8FBF 06A1 1494
